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The purpose of this research was to develop glasses that are thermally reflective, radiation-resistant, and mechanically robust. We have synthesized the La(20-x)Pb10B70:Eux series of glasses in this regard. Then, characterization, radiation shielding, structural analysis (Raman, FT-IR, DTA, SEM, XRD, and EDX), dielectrics, thermoluminescence are planned. The XRD and SEM analyses of the test samples reveal a vitreous appearance. The chemical constituents are identified by the EDX analysis in terms of their percentage of atomic weight. The density (2.592 g/cm3) and molar volume (45.44 cm3 mol−1) of the fabricated glass were evaluated as physical properties. The glass transition temperature (approximately 273 °C) and thermal stabilities (0.656 percent) of glasses are determined to be solely dependent on Eu3+ ions, according to DTA investigations. FT-IR and Raman analyses were employed to determine the various structural vibrations of the sample glass. By employing the ultrasonic velocities of the test glasses, an assessment was conducted on the micro-hardness of the glass (5.01 GPa). The shielding characteristics of radiation, such as RPE (31.6 percent) and MAC (16.9 cm2/g), indicate that the shielding behavior is solely the result of the Eu3+ ions. It has been observed that TL properties are examined at gamma irradiation intensities ranging from 5 to 25 kGy. An evaluation was conducted on the frequency factor (3.225 × 1021 S−1) and A.E. (1.785 eV) of glasses. The findings indicate that the TL characteristics of glasses are solely influenced by the Eu3+ ions. Additionally, the investigation of the dielectric properties of glasses was ascertained. The analysis focused on the dielectric constant (8.891), dielectric loss (0.026), ac conductivity (0.735 × 10–8 Ω−1 cm−1), and A.E. (1.051 eV) values of the fabricated glass. The findings suggest that the dielectric properties of glasses are entirely determined by the presence of Eu3+ ions. Overall the LBPE-1.5 glass found to be best in the structural, mechanical, optical, dielectric, radiation shielding and thermoluminescence properties. [ABSTRACT FROM AUTHOR]

The present investigation, aimed to prepare lead silicate glasses doped with samarium ions and to study it's structure, elastic, spectroscopic and thermoluminiscence properties with Al(10−x)Sbx composite influence. The objective of the investigation is to develop TL sustained good laser active resource by means of studying photo and thermoluminiscence properties. In this direction, we have prepared the glass series of Al(10−x)SbxSm0.1Pb30Si59.9 materials (where, 0 ≤ x ≤ 10, with steps of 0, 2, 4, 6, 8 and 10 mol%) after that planned for structural (XRD, FT-IR, DTA, EDS & SEM), Optical (UV & PL) and thermoluminescence characterization. The XRD and SEM studies reveal the glassy behavior of test samples. The EDX analysis signifies the chemical constitutes with atomic weight %. The physical properties such as density and molar volume of glasses were evaluated. The DTA studies of glasses reveal the glass transition and crystallization temperature points. The values of thermal stabilities of glasses found to be purely function of Sb3+ ions. Various structural vibrations of test glass conformed using FT-IR studies. Using ultrasonic velocities of the test glasses, the glasses' micro-hardness was evaluated. From the absorption spectra, the Judd–Ofelt intensity parameters (Ω2, Ω4, Ω6) have been calculated. The PL spectra under stimulation at 402 nm show a prominent reddish–orange emission at 602 nm. The experimental lifetimes (τr) of the 4G5/2 → 6H7/2 (602 nm) luminescence transition were measured using the decay spectral profiles of this transition. The evaluated emission cross-sections (σse), branching ratios (βr), and quantum efficiency (η) allow us to speculate that the lead silicate glasses doped with Sm3+ ions are ideally suitable as potential gain mediums for visible reddish orange lasers pumped directly by readily available 405 nm laser diodes. Quantum efficiencies of the produced glasses are obtained using a decay curve analysis. The emission spectra used to establish the developed glasses' reddish orange emission are used to compute the CIE chromaticity coordinates. It is evident from the stated fluorescent properties that the developed glasses are suited for reddish–orange laser applications, particularly in opto-electronic devices. From all of the values obtained, it can be observed that SAS6 glass code is ideally suited for reddish–orange laser applications. The TL properties are studied at 30 kGy gamma irradiation dose range. The frequency factor and A.E. of glasses were evaluated. This reveals that the TL behavior of glasses is a purely function of Sb3+ ions. Overall, the Al(10−x)SbxSm0.1Pb30Si59.9 glasses prepared are mechanical hard, TL effective, and optically useful resources. [ABSTRACT FROM AUTHOR]

The current research aims to develop an optically active, thermally luminescent, and radiation-shielding glass resources. For that, we have planned to develop a glasses of the chemical composition Ba(25-x)La15Si60Nix (where, 'x' = 0, 0.2, 0.4, 0.6, 0.8 & 1.0 mol%). There after the developed glasses are planned for structure, physical, mechanical, radiation shielding, optical and thermoluminescence characterization. The XRD & SEM studies reveal the glassy behavior. The EDS analysis signifies the chemical constitutes with atomic weight %. The physical properties such as density (~ 2.625 gm/cm3), molar volume (~ 48.48 cm3 mol−1) and refractive index (1.649) of glasses are evaluated. The DTA studies of glasses reveal the GTT (~ 429.5 °C) and thermal stabilities (1.593) evolutions are purely function of Ni2+ ions. Using ultrasonic velocities of the test glasses, the glasses' micro-hardness (~ 2.82 GPa) was evaluated. Radiation shielding properties such as RPE (~ 36.55%) and MAC (~ 16.556) reveal the shielding behavior is purely a function of Ni2+ ions. Using the optical absorption spectra, the bandgap (~ 1.21 eV) of the glasses evaluated. These values also purely function of Ni2+ ions. Using the photoluminescence spectra the luminescence analysis of glasses studied. The variations in values of emission cross section (~ 1.21 × 109, cm2) and Chromacity colour co-ordinates also suggesting emission range of glasses is purely function of Ni2+ ions. The TL properties are studied at 0 and 50 kGy gamma irradiation dose range. The frequency factor (~ 3.062 × 1021, S−1) and A.E. (~ 1.798 eV) of glasses were evaluated. This reveals that the TL behavior of glasses is a purely function of Ni2+ ions. Overall, the NSBL glasses prepared are mechanical hard, TL effective, optical and radiation shielding resources. [ABSTRACT FROM AUTHOR]

The objective of the study is to prepare Ag+-doped ZnO nano crystals and to assess their structure, optical behavior, TL analysis, photocatalytic activity. Using sol–gel technique the Ag+-doped ZnO nano crystals prepared. Using the FT-IR, XRD, BET surface area, SEM, EDX characterization techniques, we have examined the structure of the developed samples. The TL analysis of samples was done under a dose of 25 kGy gamma irradiation. Trap depth parameters of the samples evaluated. Which suggested the ZnO nano crystals doped with Ag+ ions are purely TL active. The optical studies such optical absorption, photoluminescence of samples reveal their optical behavior. The optical band gap of the samples also evaluated. Which is increasing with increase in concentration of Ag+ ions in ZnO nano crystals. Using the MV (10 ppm) and CR (10 ppm) dyes, under visible light the photocatalytic activity of the samples reported. At a reaction period of 90 min, the nano powder containing 1.0 mol% Ag+-doped ZnO nano crystals and a band gap energy of 2.75 eV demonstrated the best photocatalytic efficiency (∼91 %) in both colors. The evaluation was done on the impact of radical scavenger research and catalyst dosage on degrading efficiency. The rate of reaction in the presence of 1.0 mol% Ag+-doped ZnO nano crystals was four times higher than the ZnO catalyst's rate constants, and the degradation reaction follows pseudo-first-order kinetics. The degrading process shows pseudo-first-order kinetics, and the reaction rate was four times higher than the ZnO catalyst in the presence of 1.0 mol% Ag+-doped ZnO nano crystals. It took three cycle runs for the degrading efficiency to drop by 1 %. Thus, 1.0 mol% Ag+-doped ZnO nano crystals was employed as a promising photocatalyst with strong reusability potential for the degradation of textile colors, which will be very beneficial. [ABSTRACT FROM AUTHOR]

• India is vulnerable to Compound Dry and Hot Extremes (CDHEs) yet lacks attention. • A shift in studying individual extremes to a compound perspective is paramount. • We reviewed recent advances in CDHEs characterization, drivers, and prediction. • Discusses the challenges and future directions of CDHEs research in India. Compound Dry and Hot Extremes (CDHEs) is gaining attention compared to individual dry or hot extremes, due to their amplified impacts on both the population and ecosystems in India. This underscores the importance of transitioning from studying individual extremes to adopting a compound perspective. Despite this, investigation of CDHEs during the Indian summer monsoon remain limited, and a comprehensive review of methodologies for the investigation of CDHE is absent. This review systematically synthesizes recent literature, covering concepts of CDHE with illustrative examples, including identification, characterization, drivers, and prediction. It illustrates three widely used methods for the identification of CDHEs along with their advantages and disadvantages. Furthermore, it describes concepts with illustrative examples to investigate the characteristics (frequency, spatial extent, timing, duration, severity, and likelihood), explores drivers using event coincidence analysis and a complexity-based framework, and discusses the strengths and weaknesses of a logistic regression model for predicting the occurrence of CDHE. In light of the growing significance of CDHEs, we suggest future directions for Indian CDHE research, including an improved characterization of CDHEs across multiple temporal and spatial scales, a deep understanding of the physical mechanism, a robust evaluation of climate models, attribution and projection, and a comprehensive impact assessment. CDHEs are the new normal, and there is an urgent need to advance research on CDHEs in vulnerable regions like India to combat and mitigate their effects. [ABSTRACT FROM AUTHOR]

The objective of the study is to create a series of ZnO nano powders doped with CuO using sol–gel technology in order to look into their photocatalytic activity for the photodegradation and cleaning process. XRD, BET surface area, surface morphology, chemical analysis, and FT-IR measurements have all been used to look at the nano powders' structure from this point of view. The results suggest that the materials were made at the nanoscale level, and their hexagonal shape makes them good as catalytic nano resources. Photoluminescence and UV–visible diffusion reflection spectroscopy were also used to test the nano powders. The results show that the nano powders that were made are visually active. To find out how photocatalytic the nanoparticles are, they were used to break down CR (10 ppm) and MV (10 ppm) dyes when exposed to light. The nano powder with 1.0 mol% of CuO doped ZnO nanoparticles had the highest photocatalytic efficiency (86 %). It had a band gap energy of 3.15 eV and reacted with both dyes for 90 min. Researchers looked at radical scavengers and the effect of catalyst dose on how well they broke down substances. The reaction that broke down had pseudo-first-order kinetics, and the rate of the reaction was four times faster when 1.0 mol% Cu was added to the ZnO catalyst. The degradation efficiency only dropped by 1 % after three rounds of the process. Because of this, the 1.0 mol% Cu-ZnO was used as a photocatalyst that broke down textile dyes well and had a lot of promise to be used again. The samples were also checked for thermoluminescence while they were exposed to 25 kGy of gamma radiation. Samples were tested for their trap depth characteristics, indicating the test samples' potential for TL activity. [ABSTRACT FROM AUTHOR]

The quantification of spatial propagation of extreme precipitation events is vital in water resources planning and disaster mitigation. However, quantifying these extreme events has always been challenging as many traditional methods are insufficient to capture the nonlinear interrelationships between extreme event time series. Therefore, it is crucial to develop suitable methods for analyzing the dynamics of extreme events over a river basin with a diverse climate and complicated topography. Over the last decade, complex network analysis emerged as a powerful tool to study the intricate spatiotemporal relationship between many variables in a compact way. In this study, we employ two nonlinear concepts of event synchronization and edit distance to investigate the extreme precipitation pattern in the Ganga river basin. We use the network degree to understand the spatial synchronization pattern of extreme rainfall and identify essential sites in the river basin with respect to potential prediction skills. The study also attempts to quantify the influence of precipitation seasonality and topography on extreme events. The findings of the study reveal that (1) the network degree is decreased in the southwest to northwest direction, (2) the timing of 50th percentile precipitation within a year influences the spatial distribution of degree, (3) the timing is inversely related to elevation, and (4) the lower elevation greatly influences connectivity of the sites. The study highlights that edit distance could be a promising alternative to analyze event-like data by incorporating event time and amplitude and constructing complex networks of climate extremes. [ABSTRACT FROM AUTHOR]

Adequate and efficient precipitation data is a major concern due to its spatiotemporal variability and topographic and climatic factors. Satellite-based products are an alternative for a reliable precipitation estimate in basins having a complicated topography and diverse climate zones. Satellite products with global coverage and continuous data are freely available; however, understanding spatial connections is essential for reliable hydrological applications. In this study, complex network concepts like clustering coefficient, degree, degree distribution, average neighbour and architecture employed to investigate spatial connections in a basin. We also identified influential grid points in the precipitation network using weighted degree betweenness. Our results reveal that the correlation method does not significantly affect the network topology. However, the correlation threshold influences the spatial distribution of the clustering coefficient and degree values of precipitation network. The spatial distribution of clustering coefficient and degree indicated an inverse relationship independent of similarity measures and correlation thresholds. The architecture of precipitation based on satellite and observed data shows small-world behaviour for the certain correlation threshold range. Our findings unravel spatial precipitation connections and provide a way for hydrological applications in further research. [ABSTRACT FROM AUTHOR]

Compound extremes exhibit greater adverse impacts than their univariate counterparts. Studies have reported changes in frequency and the spatial extent of extremes in India; however, investigation of compound extremes is in the infancy state. This study investigates the historical variation of compound dry and hot extremes (CDHE) and compound wet and cold extremes (CWCE) during the Indian summer monsoon period from 1951 to 2019 using monthly data. Results are analyzed for 10 identified homogeneous regions for India. Our results unravelled that CDHE (CWCE) frequency has increased (decreased) by 1–3 events per decade for the recent period (1977–2019) relative to the base period (1951–1976). Overall, the increasing (decreasing) pattern of CDHE (CWCE) is high across North-central India, Western India, North-eastern India and South-eastern coastlines. Our findings help in identification of the parts of the country affected by frequent and widespread CDHE during the recent period, which is alarming. More detailed assessments are required to disentangle the complex physical process of compound extremes to improve risk management options. [ABSTRACT FROM AUTHOR]

Intrinsic predictability is imperative to quantify inherent information contained in a time series and assists in evaluating the performance of different forecasting methods to get the best possible prediction. Model forecasting performance is the measure of the probability of success. Nevertheless, model performance or the model does not provide understanding for improvement in prediction. Intuitively, intrinsic predictability delivers the highest level of predictability for a time series and informative in unfolding whether the system is unpredictable or the chosen model is a poor choice. We introduce a novel measure, the Wavelet Entropy Energy Measure (WEEM), based on wavelet transformation and information entropy for quantification of intrinsic predictability of time series. To investigate the efficiency and reliability of the proposed measure, model forecast performance was evaluated via a wavelet networks approach. The proposed measure uses the wavelet energy distribution of a time series at different scales and compares it with the wavelet energy distribution of white noise to quantify a time series as deterministic or random. We test the WEEM using a wide variety of time series ranging from deterministic, non-stationary, and ones contaminated with white noise with different noise-signal ratios. Furthermore, a relationship is developed between the WEEM and Nash–Sutcliffe Efficiency, one of the widely known measures of forecast performance. The reliability of WEEM is demonstrated by exploring the relationship to logistic map and real-world data. [ABSTRACT FROM AUTHOR]

Abstract Glass materials of composition CaO–Y 2 O 3 –B 2 O 3 –P 2 O 5 added with different concentrations of NiO (Ni2+:CYBP) are synthesized by conventional rapid melt quenching method. Various physical properties of these glasses such as polaron radius (r p), molar volume (V m), optical basicity (Λ th) and refractive index (μ) are studied. As an elastic characterization Young's modulus (Y), Poison ratio (σ) and micro hardness (H) of these glasses are studied. These grades suggest that the prepared materials are mechanically hard and exhibiting covalently interlinked structure. Further these samples are characterized by various techniques such as differential thermal analysis, thermoluminiscence, optical absorption, photoluminescence, Ionic conductivity and dielectric dispersion. The thermoluminiscence grades such as peak temperature maximum (T m), shape symmetry factor (μ sf) and activation energies (E τ , E δ and E ω) are studied at various UV irradiation levels. These results strongly recommended that the both electron and hole trap centers were created at the deeper trap levels and contribute higher orders of thermoluminiscence emission with in these glasses subjected to higher orders of temperature and UV irradiation. The various optical absorption and photoluminescence factor's such as, optical band gap (E o), nephelauxetic ratio (β), emission cross section (Ω), branching ratio (ξ) and radiative life times (τ) are studied. These grades found to be maximum for the material which has 0.5 mol% of NiO concentration may be most suggestible for optoelectronic application. The dc and ac conductivity (σ dc & σ ac) of these glasses are estimated. The various dielectric parameter's such as loss tangent (Tan (ϕ)), temperature region of relaxation (ΔT), density of states near Fermi level (N(E f)), activation energies of both dipoles and conduction (E d and E c) are also calculated. These reports clearly disclose that the octahedrally located Ni2+ ions are increasing with increase NiO concentration with in present calcio yttria borophosphate glasses. [ABSTRACT FROM AUTHOR]

Compound dry and hot extremes (CDHE) are periods of prolonged dry and hot weather. Their joint occurrence typically impacts society and nature stronger compared to the occurrence of the single hazards. Understanding the likelihood, variability and drivers of CDHE is challenging due to the complexity of the climate system involving interactions and feedbacks among atmosphere-land processes. In this study, we first investigate the role of the dependence between precipitation and temperature for the likelihood of CDHEs. We demonstrate that both the dependence strength and its type, i.e. the degree of tail dependence, substantially affect the CDHE likelihood. We then analyze the space-time variation of CDHE characteristics during the Indian Summer Monsoon across India for the period 1961–2014. We find strong negative association and substantial tail dependence between precipitation and temperature in some regions. Event coincidence analysis reveals that low soil moisture preconditioned by dry extremes is responsible for 55–65% of CDHE occurrence. Our analysis of the temporal evolution of CDHE characteristics finds an increasing negative association between precipitation and temperature leading to a 2 to 3-fold rise of CDHE frequency for some regions of India. • CDHE likelihood depends strongly on the type and strength of precipitation-temperature dependence. • Dependence between low precipitation and high temperature exhibits strong space-time variation. • Low soil moisture preconditioned by dry extremes contributes to CDHE occurrence and its spatial diversity. • CDHE frequency shows a 2 to 3-fold rise for some regions for the period 1961–2014. [ABSTRACT FROM AUTHOR]

• Spatiotemporal dependence between soil moisture (SM) and precipitation (P) over India investigated using Tail Dependence and Event Coincidence Analysis. • The precursor coincidence rate quantifies the fraction of P extreme events happening after SM has already attained extreme state. • Basin-scale analysis of temporal evolution of precursor coincidence revealed distinct patterns for major river basins over India. • Higher SM anomalies triggering P extremes is explored using trigger coincidence rate. Anthropogenic climate change has impacted almost all phases of the global water cycle. Growing consensus asserts that extreme precipitation events will only rise in the years to come. However, an increase in extreme precipitation events does not necessarily correspond to higher flood risk. Much onus lies on the antecedent conditions before the storm events. Despite the importance of Soil Moisture (SM) – Precipitation (P) dependence in runoff generation, relatively few studies have unraveled the SM – P dependence. Previous studies were constrained by the direct trivial relationship existing between SM and P, and hence there is a need to understand direction and dynamical interdependency. We employed Event Coincidence Analysis (ECA) to identify and quantify the preconditioning of P extremes by soil moisture (SM) anomalies. High precursor coincidence rate (greater than45%) was obtained for traditional flash flood-prone areas over India - Ganga river basin, West-flowing rivers of Kutch and Saurashtra including Luni, inland drainage of Rajasthan and Narmada river basin, indicating the robustness of the approach. The trigger coincidence rate reveals strong SM-P coupling over central India. Our results indicate the applicability of ECA in characterizing the spatiotemporal patterns of SM-P dependence over India. [ABSTRACT FROM AUTHOR]

• Proposed framework investigates the effectiveness of BMP/LID in managing urban surface runoff volume. • Coupled SWMM with NSGA-II for the optimal numbers of BMPs/LIDs with respect to the cost. • The optimization for minimizing cost and for maximizing benefit was simulated. • Optimization strategy employed for implementing BMPs/LIDs shows 24–26% reduction in urban flood volume. Urban surface runoff management via best management practices (BMP) and low impact development (LID) has earned significant recognition owing to positive environmental and ecological impacts. However, due to the complexity of the parameters involved, the estimation of LID efficiency in attenuating the urban surface runoff at the watershed scale is challenging. A planning analysis of employing Green Roofs and Infiltration Trenches as BMPs/LIDs practices for urban surface runoff control is presented in this study. A multi-objective optimization decision-making framework is established by coupling SWMM (Storm Water Management Model) with NSGA-II models to check the performance of BMPs/LIDs concerning the cost-benefit analysis of LID at the watershed scale. Two urbanized areas belonging to Central Delhi in India were used as case studies. The results showed that the SWMM model is useful in simulating optimization problems for managing urban surface runoff. The optimum scenarios efficiently minimized the urban runoff volume while maintaining the BMPs/LIDs implementation costs and size. With BMPs/LIDs implementation, the reduction in runoff volume increases as expenses increase initially; however, there is no noticeable reduction in flood volume after a certain threshold. Contrasted with the haphazard arrangement of BMPs/LIDs, the proposed approach demonstrates 22%–24% runoff reductions for the same expenditures in watershed 1 and 23%–26% in watershed 2. The result of the study provides insights into planning and management of the urban surface runoff control with LID practices. The proposed framework assists the hydrologists in optimum selection and placements of BMPs/LIDs practices to acquire the most extreme ecological advantages with the least expenses. [ABSTRACT FROM AUTHOR]

• The Ba (10-x) Mn x La 30 Si 60 glasses are capable of radiation shielding. • The microhardness (10.784 ∼ GPa) range, suggest higher rigidity and elastic strength. • The glass with 1.0 mol% of MnO concentration is showing better TL intensities. • The super-exchange dipole-dipole interaction and rhombic distortion with in the glasses lead to electron paramagnetic resonance. • Glasses are EPR-TL correlative upon suitable gamma irradiation. The well-known phenomenon, electron paramagnetic resonance, and thermoluminescence are used to investigate paramagnetically, and thermo-luminescent behavior of the materials to advance magneto-thermo-lumina applications. However, still, there is a necessity to introduce a correlation (or) mechanism in between electron paramagnetic resonance, and thermoluminescence to understand the radiation shielding (or) electromagnetic induction shielding phenomenon within the resource like glasses, ceramics, thin film (or) polymers. In this view, the Ba (10-x) Mn x La 30 Si 60 series of glasses are prepared. The non-crystallinity behavior and glass-forming abilities are verified by X-ray diffraction and differential thermal analysis characterization techniques. The glasses are showing non-homogeneity, de-polymerization, entropic, and de-clustering behavior with increased MnO concentration. The thermal stabilities of the glasses are reported from the DTA studies. Ultrasonic velocities were recorded to evaluate the elastic characteristics of glasses. The radiation shielding studies of glasses suggest the radiation shielding phenomenon purely a function of the MnO concentration. In this view, the results and values of mass attenuation coefficient, radiation protection efficiency, mean free path, and energy absorption build-up factor suggest more glassy thickness is required to attenuate high energy radiation. The electron paramagnetic resonance reports suggest high order of dipole-dipole super exchange interaction and rhombohedral distortion within the glasses. Which also reveals the six-state characteristic trace of the octahedral Mn2+ ions. Upon 50 kGy, γ-irradiation, the thermoluminescence properties of the glasses are reported. Trap depth parameters are calculated, which reveal the resource developed are thermoluminescent at low activation energies. Moreover, to introduce the detailed correlation between electron paramagnetic resonance, and thermoluminescence phenomenon, we have annealed the glasses under 0 to 300°C temperature and upon the 0 to 50 kGy γ - irradiation dose level. In this view, the results upon the electron paramagnetic resonance and thermoluminescence properties obtained for the glasses are highly correlative. [ABSTRACT FROM AUTHOR]

CuO inclusive silicate glasses are well known for various semiconductor applications. However, there is a lot of demand and necessity of high efficient opto-dielectric materials. In view of this, the glasses of chemical composition (30 – x) CaO + (10) Bi 2 O 3 + (60) SiO 2 + (x) CuO have been synthesized and studied for their structural, optical and dielectric characterization techniques. Glassy behaviour of CuO undoped glass and ceramic behaviour of all other CuO doped glasses conformed by structural characterization. The elastic modulus and micro hardness of glass and glass ceramics reveal their inter connected covalent structure. Trap depth parameters (T m , E τ , E δ , E ω & μ s) have been determined and analysed under irradiation, and found that 0.3 mol% CuO -doped glass ceramic under 30 kGy of irradiation dose exhibiting better TL output. Dielectric relaxation studies of the glass ceramics suggested that mixed conduction of both ionic and electronic. Observed dielectric results; dielectric constant (ε r), dielectric loss (tanφ), temperature region of relaxation (ΔT), low activation energie's for conduction (E a) and AC Conductivity (σ ac) suggesting that the glass ceramics are dielectric. Optical band gap (E o), transition probability (A t) and emission cross section (σ) corresponding to the emissive transition 3D 1 → 1S 0 assessed by optical techniques. All the results suggests that 0.3 mol% CuO -doped glass ceramic is a useful opto-dielectric resource. • Thermal stability evaluations advised the glasses prepared were hard. • Trap depth parameters of studied glass ceramics under 30 kGy of irradiation dose suggesting, 0.3 mol% CuO-doped glass ceramic is a useful TL asset. • Transition probability and emission cross section corresponding to the emissive transition 3D 1. → 1S 0 assessed by PL technique, suggesting 0.3 mol% CuO-doped glass ceramic is a useful luminescent resource. • Dielectric constant, dielectric loss, temperature region of relaxation low A.E.'s for conduction and AC Conductivity suggesting 0.3 mol% CuO-doped glass ceramic is a useful dielectric. [ABSTRACT FROM AUTHOR]

• Thermal stability, elastic evaluations advised the glasses prepared were flexible and hard. • Trap depth parameters (T m , μ m , E τ , E δ & E ω) advised that the glass Al 6 Sb 4 is a useful TL resource. • Glass Al 6 Sb 4 found to be best in JO Parameters (Ω 2 , Ω 4 and Ω 6) is a useful optical resource. • Radiative parameters (Δλ, A t , σ, β & τ rad) directing that the glass Al 6 Sb 4 is a useful PL asset. Silicates of neodymium oxide are well known for laser diode (or) white light emitting diode applications. However, there is a lot of need and necessity of high efficient laser (or) light emitting diodes. In such a way, the materials (10 – x) Al 2 O 3 – (x) Sb 2 O 3 – (0.1) Nd 2 O 3 – (30) PbO – (59.9) SiO 2 were synthesized, where the variable 'x' varies as 0, 2, 4, 6, 8 & 10 mol%. Dimensionally, arranged samples studied by structural, physical, elastic, thermoluminescent and optical characterization techniques. Analysis with regard to structure of present materials reveal that the glasses prepared were mechanical hard. Trap-depth parameters (T m , μ m , E τ , E δ & E ω) with regard to thermoluminiscence studies suggest, glasses prepared were thermally active for visible light. Judd – Ofelt theory well applied for optical studies. J-O Parameters (Ω 2 , Ω 4 and Ω 6) found to be relatively better and maximum (~9.49, ~ 4.96 and ~ 4.58 × 10−20 cm2) for Al 6 Sb 4 glass. Photoluminescence analysis, spectroscopic quality factor (~1.082), effective band width (Δλ ~ 41 nm), transition probability (A t ~ 1499 s−1), stimulated emission cross section (σ ~ 1.29 × 10−20 cm2), branching ratio (β ~ 48%) and radiative life time (τ rad ~ 195 μs) corresponding to the transition 4F 3/2 → 4I 9/2 of Nd3+ ions are suggesting Al 6 Sb 4 glass is an useful 1.06 μm photonic resource. [ABSTRACT FROM AUTHOR]

The chemical composition of (SiO 2) 59.9 – (PbO) 30 – (Pr 2 O 3) 0.1 – (Sb 2 O 3) x : (Al 2 O 3) y – x have chosen for present glass synthesis, where the variable 'x' varies from 0 to 10 mol% and againstly 'y' varies from 10 to 0 mol% with a step size of 2 mol%. The samples were characterized by structural, photo and thermoluminescence techniques. The evolutions of thermal stability, elastic modulus, micro hardness and glass transition quantities advised that they are mechanically hard in nature. The γ - irradiated trap-depth parameters such as A.E. (~0.371eV) and shape symmetry ratio (~0.236) related to the thermoluminiscence characterization advised that the sample code ' PAS 6 ' is a useful TL asset. The Judd - Ofelt quantities are derived from optical absorption spectra such as Ω 2 , Ω 4 and Ω 6 are found to be best for the glass code ' PAS 6 ' (~8.64, ~4.65 and ~3.88 × 10−20 cm2) is a useful optical resource. Radiative parameters derived from photoluminescence characterization such as spectroscopic quality factor (~1.198), effective bandwidth (Δλ ~ 32 nm), transition probability (A t = 1271 s−1), stimulated emission cross section (σ = 1.321 × 10−20 cm2), branching ratio (β ~ 49%) and radiative life time (τ rad = 217 μs) are advising that the sample code ' PAS 6 ' is a useful luminescent resource for various optical applications. • Thermal stability evaluations advised the glasses prepared were hard. • Trap depth parameters advised that the glass PAS 6 is a useful TL resource. • Glass PAS 6 found to be best in JO Parameters is a useful optical resource. • Radiative parameters directing that the glass PAS 6 is a useful PL asset. [ABSTRACT FROM AUTHOR]

• Accounted for temporal variability and magnitude to identify homogeneous regions of precipitation in India. • Coupling of self-organizing map with SVI reveals unique seasonal distribution of precipitation for each cluster. • South-central India; South-eastern coastlines; Konkan Coast exhibit stable clusters independent of temporal variability. • The temporal evolution of clusters unravels a new emerging pattern of Indian Summer Monsoon across Central India. Precipitation regionalization deals with an investigation of the seasonality and its temporal variability and is useful for a wide variety of applications in hydro-meteorology. The d homogeneous regions can be used as a basis for transforming the information from gauged to ungauged sites and can reduce the uncertainty in estimating the seasonal characteristics of precipitation across India. Despite several studies stressing the importance of seasonality and temporal variability to the environment, there is a lack of studies on accounting for temporal variability in regionalization. Precipitation regionalization must account for both the precipitation magnitude and its temporal variability at multiple time-scales to extract the seasonality of a region representing coherent local and inter-annual variability. Therefore, in this study, we propose a framework for precipitation regionalization, considering both precipitation magnitude and its temporal variability. High resolution (0.25° × 0.25°) gridded daily precipitation time series over the period 1901–2013 from Indian Meteorological Department (IMD) was used for the evaluation of the framework. First, the historical daily time series was transformed into multiple time scales, i.e., annual, seasonal, and monthly time scales. Entropy-based standardized variability index was used to measure the inter-annual variability of precipitation at each time scale. Regionalization of grid points was performed using self-organizing maps, an artificial neural network. Ten distinct regions were identified that can be tied back to two general categories, such as climate characteristics and physical characteristics. Coupling of the self-organizing map with standardized variability index reveals unique seasonal distribution of precipitation for each region. The temporal evolution of clusters unravels a new emerging pattern across Central India. Consideration of temporal variability plays an insignificant role in the shape, size and stability of south-central India, south-eastern coastlines, and Konkan Coast. Intriguingly, separate Rain-belt and Rain-shadow Western Himalayas are formed due to the difference in topography and seasonal characteristics of precipitation. The temporal evolution of clusters unravels a significant change in the occurrence of the 50th percentile monsoon after the 1940s across the north-western region; a significant increase in the 50th percentile monsoon after the 1940s across western India, and decrease in the 50th percentile monsoon after the 1980s in the north-central Region. [ABSTRACT FROM AUTHOR]

• A normalized entropy measure, Standardized Variability Index, is proposed. • Trend analysis shows one-third of the country experienced a significant increase. • More extreme rainfall events in the near future are anticipated. Understanding the spatiotemporal variability of rainfall is vital for water resources planning and management, flood and drought mitigation, and erosion control, among others. Despite the progress in this direction, through proposal of many different approaches and their applications to rainfall data at various regions around the world, our knowledge of the spatiotemporal variability of rainfall remains limited. Studies in this direction have largely focused on the amount of rainfall and its spatial patterns, and investigations of spatiotemporal variability at multiscale are limited. In this study, we introduce a novel measure, Standardized Variability Index (SVI), based on the concept of entropy to investigate the spatiotemporal variability of gridded rainfall in the Indian subcontinent at different timescales. The results show distinct spatial patterns in the inter-annual rainfall variability at all timescales. Also, the intra-annual variability of rainfall amount, as well as rainy days, is found to increase from east to west of India. The Mann-Kendall trend test at different timescales reveals significant increase in rainfall variability. In addition, coupling the mean annual rainfall with SVI enables a relative assessment of the water resources availability. [ABSTRACT FROM AUTHOR]

• The observed difference in glass crystallization to glass transition temperature from DTA spectra of the existing glass resources suggest that the decrease in devitrification up to 0.4 mol% of CoO concentration. There after the materials prepared were following quite reverse trend with further increase of CoO concentration. • The evaluations of both elastic module's, micro hardness & thermal stability of existing glasses are quite better than the evaluations of classical borate (or) borophosphate glasses might be more useful. • UV irradiated thermoluminiscence of present glasses are reported. All observed TL measurements suggest that the sample of 0.4 mol% of CoO concentration ( δ 4) exhibiting good shape symmetry factor (u) and low AE's (E τ , E δ & E ω) under 15 min of UV irradiation might be good TL asset. • The optical evaluations such as crystal field stabilization energy (D q), racah (B & C) and nephelauxetic ratio (β 0) parameters are projected. The variation in these parameters with increase in CoO content lead to decrease in optical band gap (E o) evaluations, which are found to be least for the glass sample of 0.4 mol% CoO concentration might be good optical asset to develop novel class of laser active mediums. • The radiative out comes of emissive cross section and transition probability of the peaks corresponding to the transitions 2T 1g (H) → 4T 1g (F) & 4T 1 (4P) → 4A 2 (4F) are exhibited best for the glass prepared with 0.4 mol% of CoO concentration might be most useful as radiative resource. The glasses of composition (25-x) LiF–05 Bi 2 O 3 –15 P 2 O–55 SiO 2 : x CoO have prepared (where 'x' is ranging from 0 to 0.5 mol% in step size of 0.1). Prepared samples are characterized by both structural and optical techniques. The results drawn from structural reports suggest that the samples prepared were exhibiting covalently associated interlinked structure. Thermal stability findings from differential thermal analysis disclose that the samples prepared are glassy in nature. X-Ray diffraction reports strongly acclaim the differential thermal analysis conclusions back too. Thermoluminiscence measurements suggest that the sample of 0.4 mol% of CoO concentration exhibiting good shape symmetry factor and low activation energy (~ 0.65) under 15 min of UV - irradiation might be good thermoluminiscence asset. The optical evaluations such as Racah parameters, crystal field stabilization energy and nephelauxetic ratio are additionally projected. The variation in these evaluations with increase in CoO concentration further lead to decrease in optical band gap (~ 2.31 eV) evaluations, which are found to be least for the glass models of 0.4 mol% CoO concentration might be good optical asset to develop novel class of laser active mediums. The radiative evolutions of both emission cross section and transitions probability corresponding to the emissive peaks 2T 1g (H) →4T 1g (F) &4T 1 (4P) →4A 2 (4F) assessed by Photoluminescence technique. All the results drawn from radiative studies are due to octahedrally co-ordinated Co2+ ions and also found to be best for the sample of 0.4 mol% CoO concentration might be useful luminescent resource. [ABSTRACT FROM AUTHOR]

A series of glass composites [( Sb 2 O 3 ) 0.05 (SiO 2) 0.65 ]–[ (PbO) (0.3 - x) :( Cr 2 O 3 ) x ] ( 0 ≤ x ≤ 0.01 mol%) were synthesized. Elastic, thermoluminescence, direct current (dc) conductivity and dielectric characteristics of these glass composite materials were studied. The investigations on these glass composites have indicated that the chromium ions exhibit two different oxidation states, such as Cr 3 + and Cr 6 + . The variation in poison ratio (σ ) with micro-hardness (H) plots suggests that the glass composites were prepared with a strongly and covalently connected internal structure. The observed thermoluminescence output increased with an increase in the dose of UV-irradiation. The observed peak positions of these thermoluminescent curves were shifted towards higher temperature regions. The enhanced thermoluminescence output results even recommended that both e - and h + trap cantres were created at the deeper trap levels and contribute to thermoluminescence emissions at higher temperatures. The dc conductivity (σ dc) and activation energy evaluations are also observed. Dielectric parameters such as density of energy states N (E f) , temperature region of relaxation and loss tangent (tan δ ) were calculated. The linear relationship between variation in alternating current conductivity ( σ ac ) and activation energy suggests that good amounts of polaron hopping with an increase in Cr 2 O 3 concentration in these materials were observed. The grades of loss tangent and the number of energy states near the Fermi level suggest that the materials prepared are highly useful in dielectrics. [ABSTRACT FROM AUTHOR]

In this study, we obtained nickel oxide-doped CaAl 2 SiO 6 glasses and analyzed their structural, optical, thermoluminescent, and photoluminescent properties. In general, NiO-doped glasses are useful as optical materials. However, optical materials such as glasses containing Ni2+ ions require refinement of their properties in terms of their structure, thermal stability, microhardness, electrical conductivity, and luminescence to facilitate the development of advanced thermoluminescent materials. Thus, Ni2+ ionic CaAl 2 SiO 6 glasses were synthesized and tested in this study. We observed the amorphous behavior of samples by X-ray diffraction, scanning electron microscopy, differential thermal analysis, and Fourier transform-infrared (FT-IR) spectroscopy. The order of density, oxygen packing density, polaronic radius, molar volume, and refractive index were evaluated for the glasses. The glass transition temperatures were identified using DTA to assess the order of the thermal stabilities, where the highest was found for the Ni 0.6 Ca 9.4 Al 30 Si 60 glass. The modes of molecular vibrations for Ni–O–Ni, Ca–O–Ca, Al–O–Al, and Si–O–Si molecules were identified using FT-IR. The highest transmittance intensities were determined for the Ni 0.6 Ca 9.4 Al 30 Si 60 glass. The order of the electrical conductivity and activation energy were obtained for glasses using DC conductivity measurements, where the highest was found for the Ni 0.6 Ca 9.4 Al 30 Si 60 glass. Optical absorption spectra were recorded for the glasses to determine the order of the band gap (∼0.78 eV) and nephelauxetic ratio (0.799). The photoluminescence was recorded for the glasses at an excitation wavelength of 400 nm to determine the order of the transition probability (∼1.85 S–1) and luminescence emission cross section (∼0.819 × 10−34 cm2). The highest transmittance intensities were obtained for the Ni 0.6 Ca 9.4 Al 30 Si 60 glass. Thermoluminescence was recorded for the glasses under gamma irradiation at a dose of 30 kGy, which yielded the shape symmetry factor (∼0.535%), frequency factor (1.31 S–1), and activation energy (∼0.551 eV). Irradiative thermoluminescent analysis suggested a higher order octahedral tendency, and the divalent oxidation states for nickel ions in the glass with an NiO concentration of 0.6 mol% obtained the best thermoluminescent intensities. The orders of the elastic modulus, nephelauxetic ratio, and microhardness for the glasses suggested covalently connected elastic lattices. • Microhardness range of the glasses, reveal the elastic strength. Which is found to be high in comparison with borophosphate glasses. • The d. c. Conductivity range of glasses suggest higher orders of polaronic radius, interstitial defects, and the octahedral tendency of Ni2+ ions, with in the glasses. • The order of ionic radius, trap centers, and the octahedral tendency of Ni2+ ions, with in the glasses suggest glasses will be useful advanced TL resource. The shape symmetry factor and low A.E.'s of the glasses under thermoluminescence studies suggest materials are TL active for low energies. • The order of the optical bandgap, transition probability and cross-section of the glasses are a highly suggestible for photonic resource. Due to the high orders of refractive index, the octahedral tendency of Ni2+ ions, and nephelauxetic ratio, the Ni-0.6 glass exhibited best spectroscopic properties in comparison. [ABSTRACT FROM AUTHOR]

Accelerating climate change is causing considerable changes in extreme events, leading to immense socioeconomic loss of life and property. In this study, we investigate the characteristics of extreme climate events at a regional scale to -understand these events' propagation in the near future. We have considered sixteen extreme climate indices defined by the World Meteorological Organization's Expert Team on Climate Change Detection and Indices from a long-term dataset (1951–2018) of 53 locations in Gomati River Basin, North India. We computed the present and future spatial variation of theses indices using the Sen's slope estimator and Hurst exponent analysis. The periodicities and non-stationary features were estimated using the continuous wavelet transform. Bivariate copulas were fitted to estimate the joint probabilities and return periods for certain combinations of indices. The study results show different variation in the patterns of the extreme climate indices: D95P, R95TOT, RX5D, and RX showed negative trends for all stations over the basin. The number of dry days (DD) showed positive trends over the basin at 36 stations out of those 17 stations are statistically significant. A sustainable decreasing trend is observed for D95P at all stations, indicating a reduction in precipitation in the future. DD exhibits a sustainable decreasing trend at almost all the stations over the basin barring a few exceptions highlight that the basin is turning drier. The wavelet power spectrum for D95P showed significant power distributed across the 2–16-year bands, and the two-year period was dominant in the global power spectrum around 1970–1990. One interesting finding is that a dominant two-year period in D95P has changed to the four years after 1984 and remains in the past two decades. The joint return period's resulting values are more significant than values resulting from univariate analysis (R95TOT with 44% and RTWD of 1450 mm). The difference in values highlights that ignoring the mutual dependence can lead to an underestimation of extremes. [ABSTRACT FROM AUTHOR]