Narrow Results

Lead iodide (PbI${}_2)$ nanoparticles in silica have been synthesized using the sol–gel method. The aqueous method of synthesis has been used for undoped PbI₂ nanoparticles. These nanoparticles have been stabilized using thioglycerol acting as the capping agent. The narrow-sized PbI₂ nanoparticles have been obtained, which are characterized by size-dependent properties. The PbI₂ nanoparticles have been characterized and their properties have been investigated by using various experimental techniques like Ultraviolet–Visible (UV–Vis) Absorption Spectroscopy, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Photoluminescence (PL), Atomic Force Microscopy (AFM), etc. The lateral dimension of PbI₂ nanoparticles in silica varies from 9 Å to 27 Å. PbI₂ thin films were deposited on silicon wafers by using the dip coating method and analyzed by using various characterization techniques like Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-rays (EDAX), Mapping, etc. The aim of this work is to synthesize PbI₂ nanoparticles with a size less than or comparable to the Bohr diameter of the exciton. The characterization results showed that the cluster size increases with the increasing film thickness and by the heat treatment in air atmosphere. The PbI₂ nanocrystals embedded in silica films have been studied in this paper. The PbI₂ nanoparticles and the PbI₂ sol–gel thin films can be used in optoelectronic device applications and chemical industrial applications. To the best of our knowledge, there are no studies on the synthesis of PbI₂ nanoparticles in silica using the sol–gel route and on the preparation of PbI₂ thin films using the dip coating method.

Nanodiamonds (NDs) have unique optical and mechanical characteristics, surface chemistry, extensive surface area and biocompatibility, and they are nontoxic, rendering them suitable for a diverse range of applications. Recently, NDs have received significant attention in nano-biomedical engineering. This review discusses the recent advancement of NDs’ biomedical engineering, historical background, basic introduction to nanoparticles and development. We summarize NDs’ synthesis technique, properties and applications. Two methodologies are used in ND synthesis: bottom-up and top-down. We cover synthesis methods, including detonation, ball milling, laser ablation, chemical vapor deposition (CVD) and high pressure and high temperature (HPHT); discuss the properties of NDs, such as fluorescence and biocompatibility. Due to these properties, NDs have potential applications in biomedical engineering, including bioimaging, biosensing, drug delivery, tissue engineering and protein mimics. Further, it provides an outlook for future progress, development and application of NDs in biological and biomedical areas.

Network reliability plays an important role in analysis, synthesis and detection of real-world networks. In this paper, we first propose the concept of hypernetwork reliability, which generalizes the concept of network reliability. The model for hypernetwork reliability studies consists of a hypergraph with perfect reliable vertices and equal and independent hyperedge failure probability $1-p$. The measure of reliability is defined as the probability that a hypergraph is connected. Let $H$ be an $r$-uniform hypergraph with the number of vertices $n$ and the number of hyperedges $m$, where every hyperedge connects $r$ vertices. We confirm the possibility of the existence of a fixed hypergraph that is optimal or least for all hyperedges same survival possible $p$. It is simple to verify that such hypergraph exists if $m=[\frac{n-1}{r-1}]$. For a kind of 2-regular 3-uniform hypergraphs, we calculate the upper and lower bounds on the all-terminal reliability, and describe the class of hypergraphs that reach the boundary.

Based on the working principle of the signal detection and servo feedback control of the electrostatic accelerometer, in this paper, the main electronic noise components affecting the measurements of the accelerometer are analyzed and the corresponding expressions are determined. The resolution of the designed electrostatic accelerometer is lower than 10${}^{-9}$m/s²/Hz${}^{1/2}$, which cannot be verified directly due to limitations imposed by the vibration of the ground environment. However, it can be evaluated indirectly by the testing of electronic noise under open-loop conditions. Through this process, the resolution of 3× 10${}^{-9}$m/s²/Hz${}^{1/2}$ of the Taiji-1 inertial sensor was verified and found to be in agreement with results obtained in orbit.

Nanostructured MgO powders have been synthesized using chemical methods. Ammonium oxalate and Magnesium sulphate were used as the precursor materials. The weight ratios of the raw materials (ammonium oxalate/Magnesium sulphate) were 0.9, 1, 1.1, 1.2, 1.3, and 1.4. As a result of chemical reaction (between them), Magnesium oxalate was synthesized. Produced samples were analyzed by XRD and SEM. The results show that the best ratio (for ammonium oxalate/Magnesium sulphate) is 1.4. Produced Magnesium oxalate powder was heated at 450 and 550°C. The final product was MgO nanopowder. XRD studies indicate that the highest ratio of MgO was observed in the specimen heated at 450°C.

The present paper attempts as how the pigments comprising of nano-sized hematite particles deposited on mica surfaces in optimum conditions offer an excellent pearlescent properties. To record the influencing parameters on the synthesis process, response surface methodology (RSM) technique was used where temperature of reaction, synthesis time and concentration of urea were selected as variable parameters. Taking into account colorimetric parameters, the whole process was then analyzed by "Design Expert" software that finally gave following optimum factors: reaction temperature=82.02°C, synthesis time=11.98 h, urea concentration=37.5 g/l. Once the above optimum parameters selected, seemingly, the spherical hematite particles of about 60 nm in diameter are deposited uniformly on mica surfaces.

A soft approach has been described for the formation of α–Fe₂O₃ nanorods by simple reaction of iron with water at a very low temperature range of 100–300°C. It is shown that the nanorods have diameters ranging from 50–80 nm, and their typical lengths are in the range of 5–10 μm. The chemical composition and crystalline structure of nanorods were investigated by various characterization techniques. The initial formation and subsequent growth of α–Fe₂O₃ nanostructures may be explained by the iron metal corrosion mechanism.

With the advent of nanotechnology, methods of synthesis have attained immense importance since it governs particle size of the materials. In this paper, we report synthesis of CaZrO₃ by simple and energy efficient method that produced ultra fine powder having particle size in the nanometers. Synthesis of CaZrO₃ was carried out using corresponding metal nitrates and mixed fuels i.e., glycine and urea at a temperature less than 500^°C. The reaction was highly exothermic in nature. The product obtained was voluminous and foamy. The as synthesized CaZrO₃ is crystalline in nature. It required no further heating. The compound was indexed using standard indexing procedure and the lattice constants matches completely with those reported in the literature. Differential Thermal Analysis (DTA) and Thermo Gravimetric Analysis (TGA) results shows that the material is highly stable internally during the whole range of temperature studied i.e., up to 1000^°C. The powder density of the material was calculated to be 5.6393 gcm^-1. BET surface area was found to be 11.505 m²/g. The particle size was calculated using density and BET surface area values. The particle size of the as synthesized CaZrO₃ was found to be 92 nm. The product was further characterized using Scanning Electron Microscope and electrical conductivity.

Bimetallic structure of nanoparticles is of great interest due to their extraordinary properties, especially in combining the specialty of the core and its shell. This work reports the effect of pH on the synthesis of Ni–Au (nickel–gold) bimetallic nanoparticles. The synthesis involves a two-step process where Ni nanoparticles were first synthesized using polyol method with hydrazine as the reducing agent. This was followed by the process of reducing to Au in the solution containing pre-prepared Ni to form Ni–Au bimetallic nanoparticles using sodium citrate as the reducing agent. The results obtained from Transmission Electron Microscopy (TEM) show that the process can possibly produce either core-shell structure, or mixture of Ni and Au nanoparticles. Magnetic property of core-shell structure investigated using Vibrating Sample Magnetometer (VSM) demonstrated typical characteristic of ferromagnetic with an increased magnetization as compared to Ni nanoparticles. The saturation magnetization (M_s) and coercivity (H_c) were obtained as 19.1 emu/g and 222.3 Oe, respectively.

This study reports the effective synthesis of multilayered graphene sheets via microwave atmospheric pressure plasma. This innovative approach streamlines and expedites graphene production and other carbon nanostructures, eliminating the need for catalysts, solvents, or complex processing conditions. Ethanol is directly injected into a microwave-generated argon plasma plume, leading to the formation of graphene. Raman spectroscopy revealed characteristic peaks (2D, G, and D bands) confirming graphene composition, with defects indicated by the D band. X-ray diffraction analysis supported these findings, indicating a broad peak at 25^∘ corresponding to the (002) plane, affirming a multi-layered graphene structure. Scanning electron microscopy exhibited crumpled, randomly oriented graphene sheets, albeit with uneven structures suggesting impurity incorporation. The presence of defects was quantified through the intensity ratio of the D to G band (I_D/I_G) in Raman spectroscopy, revealing a value of 0.80, signifying the presence of defects in the synthesized graphene. The 2D to G band intensity ratio (I_2D/I_G) suggested the existence of 7–10 graphene layers, highlighting the need for further optimization for enhanced graphene quality and purity.

The detonation of carbon- or nitrogen-containing explosives not only produces powerful shock waves but also provides elemental building blocks and a unique high-pressure and high-temperature physical environment for the construction of various nanostructures. This review highlights the situation and key progresses in the detonation approach towards diamond nanoparticles, graphitic carbon nanotubes, fullerene molecules, and gallium nitride nanocrystals. Further extension of the peaceful-use detonation applications and rational reactor design are also proposed.

An easy and novel approach is described for the formation of zinc oxide nanorods by simple reaction of zinc metal with water in a very low temperature range of 25–75°C. It offers a facile and fast route for large scale production of zinc oxide nanorods without catalysts. The diameters of the nanorods range from 30–120 nm with several micrometers in length. The resulting nanorods have been comprehensively characterized by Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive Analysis (EDX). A plausible mechanism is proposed for the formation of these nanorods and it is expected that this synthetic technique can be extended to obtain other oxides. This will contribute to broadening the range of materials.

In this work, CdSe quantum dots (QDs) were synthesized using a microwave activated reaction between NaHSe and CdSO₄ in the presence of thioglycolic acid (TGA) as capping molecule and then using a one-pot method, ZnS shell was grown subsequently around CdSe cores by a room temperature reaction based on the photo-sensitivity of Na₂S₂O₃ dissociation. Synthesized QDs were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV-visible (UV-Vis) and photoluminescence (PL) spectroscopy. All these analyses confirmed the formation of CdSe QDs and successful growth of ZnS shell around CdSe cores.

Sn precursor layer was evaporated on a glass substrate by an electron-beam evaporation method and followed by selenization using Se powder. SnSe film was successfully prepared by adjusting the selenization temperature and selenization time. The phase, microstructure and optical properties of the SnSe films were studied by X-ray diffraction, Raman spectroscopy, Scanning Electron Microscopy, and UV-Vis-NIR spectrophotometer. The results demonstrated that the pure phase polycrystalline SnSe films with a band gap of 0.93 eV could be prepared by selenizing at 450${}^{\circ }$C for 60 min. Under the irradiation of a 980 nm laser with a power of 2 mW/cm², photoelectric response characteristics of the SnSe films were tested, and the response time and recovery time of the prepared film were 62 ms and 80 ms, respectively, indicating that the SnSe film had a large application prospect in near-infrared light detection.

This paper introduces the notion of chaos synthesis by means of evolutionary algorithms and develops a new method for chaotic systems synthesis. This method is similar to genetic programming and grammatical evolution and is being applied along with three evolutionary algorithms: differential evolution, self-organizing migration and genetic algorithm. The aim of this investigation is to synthesize new and "simple" chaotic systems based on some elements contained in a prechosen existing chaotic system and a properly defined cost function. The investigation consists of eleven case studies: the aforementioned three evolutionary algorithms in eleven versions. For all algorithms, 100 simulations of chaos synthesis were repeated and then averaged to guarantee the reliability and robustness of the proposed method. The most significant results were carefully selected, visualized and commented in this report.

In our new approach, evaporation residue cross-sections for new superheavy nuclei with atomic numbers $Z=114-118$ are estimated by calculation of vital characteristics of superheavy nuclei synthesis such as the fission barrier height, the compound nucleus formation probability and the survival probability of the residue nuclei. Our presented estimation is in good agreement with available experimental data. In addition, this new approach allowed us to predict the evaporation residue cross-sections for superheavy nuclei with $Z=119$ and 120 via introducing synthesis box and compare our results with other models. It is shown that the fission barrier heights of two nuclei with $Z=119$ and 120 are comparable with their corresponding neutron separation energies. It is suggested that for the synthesis of new superheavy nuclei, it is proper to use nearly double magic nuclei such as ${}^{50}\mathrm{\text{Ti}}$ as our projectile, so that the fission barrier heights remain high.

In this paper, we applied the method developed by Santhosh and Safoora in [Phys. Rev. C  94 (2016) 024623; 95 (2017) 064611] to theoretically investigate the fusion, evaporation-residue (ER) and fission cross-sections of the synthesis of the unknown superheavy ${}^{309,312}$126 nuclei produced by using the ${}^{58}$Ni + ${}^{251}$Cf and ${}^{64}$Zn + ${}^{248}$Cm combinations. The charge asymmetry, mass asymmetry and fissility of the DiNuclear System (DNS) in the synthesis of the mentioned combinations are also estimated. The calculated results show that the ER cross-sections for the synthesis of the ${}^{309-317}$126 nuclei are predicted to be much less than 1.0fb. In particular, it has been found that there may exist a valley of the ER cross-sections in the synthesis of a superheavy $Z=126$ element, which produces the ${}^{313}$126 isotope. Subsequently, a model for the mass dependence of the ER cross-section in the synthesis of the ${}^{307-320}$126 isotopes has been proposed for the first time. On the other hand, the quasi-fission process strongly dominates over the fusion in the two concerned interacting systems. The present results, together with those reported in the previous studies, indicate that the investigated projectile–target combinations are not capable for the synthesis of the ${}^{309,312}$126 isotopes due to tiny fusion cross-sections (about 2–3zb), which go beyond the limitations of available facilities. Further studies are thus recommended to search for alternative interacting systems. In conclusion, this work provides useful information for the synthesis of the gap isotopes ${}^{308-317}$126, which have not been well studied up to date.

This paper reviews the growth and properties of L-asparagine monohydrate (L-ASPM) single crystal. The growth technique by which a well-defined bulk-sized single crystal can be grown is also reported. The various reported studies done over titled crystal signify its suitability for various optoelectronic applications. This paper also includes few derivative compounds of L-asparagine (L-ASP), their structural review has also been incorporated to evaluate its structural bonding and atomic arrangement. Various advanced characterization and their outcomes were also discussed in detail from all the available reported literature which mainly emphasizes on the vast applicability of the crystal. The L-ASPM single crystal is a potential candidate to be used in various optical applications.

In the this study, we focus on the growth of a metal-organic creatininium borate (CRB) single crystal for third-order nonlinear optical (NLO) applications. Optically transparent & wide optical band gap single crystals of CRB were successfully harvested by adopting a slow evaporation solution technique (SEST) at a constant 40${}^{\circ }$C temperature. The structural identification and lattice parameters of the grown sample were determined by powder X-ray diffraction (PXRD) using Rietveld analysis by FullProf Suite software. The occurrence of vacancy/interstitial defects produced during growth was investigated by high-resolution X-ray diffraction (HRXRD) using omega scan arrangement. A single peak with lower full width half maxima (56.4 arc s) was obtained from the scan which suggests that there were no grain boundaries for the grown crystal. Surface morphology and its features such as concentration of dislocations and defect sites on the as-grown sample were scrutinized using the etching technique. The optical band gap and UV–vis cut-off were examined and found to be 5.39 eV and 230 nm, respectively. Photoluminescence characteristics of the crystal show an emission at 377 nm upon excitation with a wavelength of 336 nm. The presence of radiative and non-radiative transitions inside the crystal due to excitation upon 266 nm laser was identified using time-resolved photoluminescence. Thermal stability and decomposition temperature of the compound were obtained by thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The third-order nonlinearity of the crystal was determined by Z-scan measurement technique with a femtosecond Ti-sapphire laser.

The WC–Co nanocomposites were synthesized by using a polymer precursor such as polyacrylonitrile, which severs as an in situ carbon source. The WC–Co nanocomposites formed are characterized by X-ray diffraction and electron microscopy. Nearly pure WC–Co nanocomposites with a particle size in the range of 60–80 nm have been obtained. The use of H₂ atmosphere enhanced the carbide formation and in turn reduced the reaction time (at high temperature). The phase purity of the products is strongly influenced by the processing conditions such as the firing temperature, time and atmosphere. This suggests that the process parameters have to be optimized before scaling up the process for commercial production.