[en] We derive an alternate analytical expression for the optimum dimensions of an electromagnetic undulator with a finite permeability lamination core. The analytical expressions are compared with earlier results under an infinite permeability approximation of the lamination core of the electromagnetic undulator design. (authors)

[en] Managing energy demand is essential for ensuring a reliable and sustainable supply, reducing environmental impacts, and achieving energy security. Governments, businesses, and individuals are crucial in shaping energy demand through policy, technology adoption, and behavioral changes. Sustainable energy planning and infrastructure development aim to balance the growing energy demand with environmental and economic goals. Energy storage devices can shave off-peak demand on the grid, reducing the need for expensive and environmentally harmful peaker power plants. This can lead to cost savings and more efficiency. Among various energy storage devices, Supercapacitors play a significant role in energy storage and have particular advantages regarding power delivery, cycle life, and dependability. They are progressively incorporated into diverse technologies and systems to improve energy storage and management solutions across numerous industries. Recently, materials like Transition metal oxides, Conducting Polymers, Carbon-based materials, and Metal-organic frameworks (MOFs) have been utilized for energy storage devices. Among these, ZIF-67 (Zeolitic Imidazolate Framework-67) gained more attention because of its various properties. It is a type of MOF and a promising material due to its high surface area, porous structure, and tunable properties. It is synthesized from relatively abundant and environmentally friendly materials, making it a potentially sustainable choice compared to other supercapacitor materials for energy storage. In the present work, a simple stirring approach is used for the synthesis of ZIF-67, and it is confirmed using X-ray Diffraction (XRD). Morphology is being studied using Scanning electron microscopy (SEM), and the obtained material's electrochemical performance, that is, cyclic voltammetry (CV), Galvanostatic Charge/Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS) tests, are being investigated on the CHI760E electrochemical workstation (author)

[en] Highlights: • PANI/C₇₀/GC Sensor has been developed for the electrochemical quantification of Herbicide Trichlopyr (TCP). • This paper is the first systematic report of electrochemical study of Trichlopyr on PANI/C₇₀ /GC Sensor. • The Fabricated sensor was applied for analysis of the TCP in real samples viz. water and tomatoes. • This is the first report for the quantification of any herbicides on fullerene C₇₀ nanocomposite. -- Abstract: The herbicide Triclopyr (TCP) is widely applied to minimize the growth of woody plants. Monitoring of TCP is of major environmental concern due to its adverse impact on aquatic organisms, soils and animals. Electrochemical behavior of TCP was investigated at C₇₀ decorated PANI modified glassy carbon sensor (PANI/C₇₀/GC). The experimental parameters, such as concentration, pH, amplitude, frequency, deposition potential were optimized. The modified sensor exhibited an excellent catalytic response towards the reduction of TCP with a well-defined reduction peak at 1.72 V. The developed sensor was characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD) and electrochemical impedance spectroscopy (EIS). The electrochemical measurements were carried out using square wave (SWV) and cyclic voltammetry (CV). The modified sensor exhibited linear calibration curve for TCP over a concentration range of 10 ngmL⁻¹–100 ngmL⁻¹ with detection limit of 1.9 ngmL⁻¹. The developed sensor could detect TCP efficiently without any interference from the common metabolites. The voltammetric procedure was applied successfully to real sample analysis with high sensitivity and good selectivity.

[en] The quest for enhancing the high-temperature stability of carbon fibers (CFs) in oxidative environments has been the subject of extensive research due to their versatile applications in various industries, like aerospace, automotive, and electronics. In this study, we explore a novel approach to achieve inherent oxidation protection in CFs by incorporating specific oxidation- inhibiting materials, polydimethylsiloxane (PDMS) and boric acid (H₃BO₃) directly into the CF precursor Polyacrylonitrile (PAN) during fabrication, to fabricate CFs by electrospinning, stabilization, and carbonization. In conclusion, the addition of PDMS and H₃BO₃ results in the formation of sealant boric oxide (B₂O₃) and silica (SiO₂) glass due to the synergistic effect which internally protects the CFs from oxidation for temperatures >600°C. The incorporation of PDMS and PDMS-H₃BO₃ into the PAN precursor improved the oxidation resistance of the fabricated hybrid CFs. The oxidation resistance of CFs is greatly increased by the presence of these protective chemicals, even at temperatures above 600°C. The concept of incorporating oxidation inhibiting materials during fabrication showcases promising results and encourages further exploration of advanced materials for enhanced carbon fiber performance. Oxidation- protected CFs have the potential to revolutionize various industries by providing lightweight, high-strength materials capable of withstanding extreme conditions, thereby enabling the development of more efficient and durable products. (author)

[en] Highlights: • X-ray developer solution contains hazardous silver with high pollutant loads. • Phycoremediation is a sustainable approach for X-ray developer solutions. • Toxicity tolerance determination is a prerequisite in phycoremediation. • Phycoremediation facilitates concomitant bio commodities production. • Phycoremediation is a sustainable way for medical effluent handling. The present research is mainly focusing on the characterization of X-ray developer solution and its toxic tolerance studies with Desmodesmus armatus towards the phycoremediation studies for removal of pollutants, silver, and concomitant lipid production. The characterization results suggested the presence of 1.229 ± 0.004 g/l BOD, 27.29 ± 0.230 g/l COD with a silver content of 0.01791 ± 0.000 g/l. The tolerance and toxicity limits of with X-ray developer solution reveals the remarkable growth of microalgae in 3:1.dilution ratio of BBM in the X-ray developer solutions. The phycoremediation with 19 days period shown the noticeable results with a relative BOD (20.86%), COD (13.88%), with 57.10% corresponding total phosphorous removal. The phycoremediation also has proven better relative silver removal potential of 44.06% on the 19th day with concomitant 1.392% lipid production. Overall, the present study shows the potential phycoremediation strategy of hazardous X-ray developer solutions with possible concurrent lipid production through a sustainable approach.

[en] The study indicates the viability of geographic information system and remote sensing data for the analysis as well as estimation of the stage and the rate of erosional processes in a Himalayan watershed for improved planning and management. The Gaj watershed lies in the outer Himalayan region of Himachal Pradesh, India, which has been characterized in to nine sub-watersheds for studying the geomorphological evolution of each separately for comparative assessment irrespective of any scale issue. The method involves the use of 30 m Cartosat (digital elevation model) for operative and time-saving data extraction of morphometric and hypsometric parameters. The estimated hypsometric integral values and the shape of the hypsometric curves reveal varying degree of erosional stages of the sub-watersheds demanding attention over the denudation activities. The results have helped in the qualitative discussions and prioritizing the sub-watershed for sustainable soil–water conservation and management, which can be useful for controlling the erosional activities at right locations in the study area.

[en] A long heated cylinder was placed near a cold wall under the incident of a Couette flow. The conventional fluid was chosen as water (H 2 O). The nanoparticle materials were selected as Al 2 O 3 and CuO. The governing Navier-Stokes and energy equations were solved numerically through a finite volume method on a staggered grid system using QUICK scheme for convective terms and SIMPLE algorithm. The dependencies of hydrodynamic and heat transfer characteristics of the cylinder on non-dimensional parameters governing the nanofluids (Particle concentrations (φ), diameter (d np ), and particle materials) and the fluid flow (Peclet number Pe and gap height ratio L) were explored here. The shifting of the front stagnation point due to the addition of nanoparticles in the base fluid was investigated. A comparison between the heat transfer enhancement (N uM ) of the cylinder and its drag coefficient’s (C D ) increment/reduction was made by presenting their ratio Nu M /CD. The least square method was applied to the numerical results to propose Nu M = Nu M (Pe) and Nu M = Nu M (L)

[en] The nonlinear phenomena are of prominent interests in understanding the particle acceleration and transportation in the interplanetary space. The ponderomotive nonlinearity causing the filamentation of the parallel propagating circularly polarized dispersive Alfvén wave having a finite frequency may be one of the mechanisms that contribute to the heating of the plasmas. The contribution will be different of the left (L) handed mode, the right (R) handed mode, and the mix mode. The contribution also depends upon the finite frequency of the circularly polarized waves. In the present paper, we have investigated the effect of the nonlinear coupling of the L and R circularly polarized dispersive Alfvén wave on the localized structures formation and the respective power spectra. The dynamical equations are derived in the presence of the ponderomotive nonlinearity of the L and R pumps and then studied semi-analytically as well as numerically. The ponderomotive nonlinearity accounts for the nonlinear coupling between both the modes. In the presence of the adiabatic response of the density fluctuations, the nonlinear dynamical equations satisfy the modified nonlinear Schrödinger equation. The equations thus obtained are solved in solar wind regime to study the coupling effect on localization and the power spectra. The effect of coupling is also studied on Faraday rotation and ellipticity of the wave caused due to the difference in the localization of the left and the right modes with the distance of propagation

[en] This paper examines the small-scale solar wind turbulence driven in view of the Alfvén waves subjected to ponderomotive nonlinearity. Filamentation instability is known to take place for the case of dispersive Alfvén wave (DAW) propagating parallel to the ambient magnetic field. The ponderomotive force associated with DAW is responsible for wave localization and these webs of filaments become more intense and irregular as one proceeds along the spatial domain. The ponderomotive force associated with pump changes with pump parameters giving rise to different evolution patterns. This paper studies in detail the nonlinear evolution of filamentation instability introduced by dispersive Alfven waves (DAWs) which becomes dispersive on account of the finite frequency of DAW i.e., pump frequency is comparable to the ion cyclotron frequency. We have explicitly obtained the perturbation dynamics and then examined the impact of pump magnitude on the driven magnetic turbulence using numerical simulation. The results show steepening at small scales with increasing pump amplitude. The compressibility associated with acoustic fluctuations may explain the variation in spectral scaling of solar wind turbulence as observed by Alexandrova et al. (Astrophys. J. 674:1157, 2008).

[en] In this work, pristine and doped Zinc Sulphide (ZnS) nanoparticles have been synthesized via chemical co-precipitation method. ZnS nanoparticles have been doped with Aluminium (Al) and Yttrium (Y) with doping concentration of 5wt% each. The structural and optical properties of the as prepared nanoparticles have been studied using X-Ray diffraction (XRD) technique and Photoluminescence spectroscopy. Average grain size of 2-3nm is observed through the XRD analysis. Effect of doping on stress, strain and lattice constant of the nanoparticles has also been analyzed. Photoluminescence spectra of the as prepared nanoparticles is enhanced due to Al doping and quenched due to Y doping. EDAX studies confirm the relative doping percentage to be 3.47 % and 3.94% by wt. for Al and Y doped nanoparticles respectively. Morphology of the nanoparticles studied using TEM and SEM indicates uniform distribution of spherical nanoparticles.