The 4D Klein-Gordon, Dirac and Quantization Equations from 5D Null Paths

Results from 5D induced-matter and membrane theory with null paths are extended to show that a particle obeys the 4D Klein-Gordon equation but with a variable mass. The Dirac equation also follows, but raises concerns about 4D quantization in the two natural 5D gauges, and reopens the question of a Regge-like trajectory for the spin angular momenta and squared masses of gravitationally-dominated systems.     

Scattering spectra and colour of disperse systems of low-absorptive particles

In this article, the results of calculations of scattering spectra of low-absorptive spherical particles are presented. It was obtained using different approximate and numerical methods. The comparative evaluations of application of single scattering approximation, the average field approximation and of the methods of computer modeling on the basis of Monte-Carlo method on various scattering multiplicity were performed. The comparison demonstrates the good agreement of calculated results with experimental scattering spectra of eye lens. By using the obtained spectral data the colour coordinates are calculated. The regularities of changes in colour characteristics in dependence of disperse system parameters are analyzed.     

The agglomeration state of nanosecond laser-generated aerosol particles entering the ICP

Fundamental understanding of aerosol formation and particle transport are important aspects of understanding and improving laser-ablation ICP–MS. To obtain more information about particles entering the ICP, laser aerosols generated under different ablation conditions were collected on membrane filters. The particles and agglomerates were then visualised using scanning electron microscope (SEM) imaging. To determine variations between different sample matrices, opaque (USGS BCR-2G) and transparent (NIST SRM 610) glass, CaF₂, and brass (MBH B26) samples were ablated using two different laser wavelengths, 193 and 266 nm. This study showed that the condensed nano-particles (∼10 nm in diameter) formed by laser ablation reach the ICP as micron-sized agglomerates; this is apparent from filters which contain only a few well-separated particles and particle agglomerates. Ablation experiments on different metals and non-metals show that the structure of the agglomerates is matrix-dependent. Laser aerosols generated from silicates and metals form linear agglomerates whereas particle-agglomerates of ablated CaF₂ have cotton-like structures. Amongst other conditions, this study shows that the absorption characteristics of the sample and the laser wavelength determine the production of micron-sized spherical particles formed by liquid droplet ejection.     

Size-related vaporisation and ionisation of laser-induced glass particles in the inductively coupled plasma

Ongoing discussions about the origin of elemental fractionation occurring during LA-ICP-MS analysis show that this problem is still far from being well understood. It is becoming accepted that all three possible sources (ablation, transport, excitation) contribute to elemental fractionation. However, experimental data about the vaporisation size limit of different particles in the ICP, as produced in laser ablation, have not been available until now. This information should allow one to determine the signal contributing mass within the ICP and would further clarify demands on suitable laser ablation systems and gas atmospheres in terms of their particle size distribution.The results presented here show a vaporisation size limit of laser induced particles, which was found at particle sizes between 90 nm and 150 nm using an Elan 6000 ICP-MS. Due to the fact that the ICP-MS response was used as evaluation parameter, vaporisation and ionisation limits are not distinguishable.The upper limit was determined by successively removing the larger particles from the aerosol, which was created by ablation of a NIST 610 glass standard at a wavelength of 266 nm, using a recently developed particle separation device. Various particle fractions were separated from the aerosol entering the ICP. The decrease in signal intensity is not proportional to the decrease in volume, indicating that particles above 150 nm in diameter are not completely ionised in the ICP. Due to the limited removal range of the particle separation device, which cannot remove particles smaller than 150 nm, single hole ablations were used to determine the lower vaporisation limit. This is based on measurements showing that larger particles occur dominantly during the first 100 laser pulses only. After this period, the ratio of ICP-MS counts and total particle volume was found to be constant while most of the particles are smaller than 90 nm, indicating complete vaporisation and ionisation of these particles.To describe the influence of different plasma forward powers on the vaporisation limit, the range 1000–1600 W was studied. Results indicate that optimum vaporisation and ionisation occurs at 1300 W. However, an increase of the particle ionisation limit towards larger particles was not observed within the accuracy of this study using the full range of parameters available for optimisation on commonly used ICP-MS instruments.     

Growth kinetic study of ionic liquid mediated synthesis of gold nanoparticles using Elaeis guineensis (oil palm) kernels extract under microwave irradiation

Gold nanoparticles (AuNPs) are the most studied nanomaterials due to their promising applications. However, surface capping of AuNPs is essential to protect aggregation for enhanced colloidal stability. In this study, a single step method was established to synthesize stable AuNPs using oil palm kernel (OPK) extract prepared in IL[EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). Ionic liquids were used for phytochemicals extraction along with capping and stabilizing of AuNPs after their synthesis. The OPK extract reduced the gold precursor, and UV–vis spectroscopy revealed a sharp surface plasmon (SPR) peaks in the region of 524–529 nm, which confirmed the formation of AuNPs. UV–vis and TEM analysis indicated that microwave assisted synthesis was rapid to synthesize well dispersed and small sized AuNPs in comparison with conventional heating. FTIR analysis of kernels extract before and after its reaction with gold precursor identified the involvement of CH aromatic groups, polyphenolic OH groups, and carbonyl amide groups that are responsible for reduction of trivalent gold ions to AuNPs. EDAX and XPS analysis were performed to identify the elemental gold and its surface interaction with ILs and other organic moieties. Colloidal AuNPs kept at room temperature for periods of six months were remained stable. The change of pristine nanostructure arises due to involvement of different driving forces during growth of nanoparticles. Thermodynamically instability of nanomaterials may leads to Ostwald Repining (OR) or adopt complex pattern of growth and undergo coalesce and orientation attachment (OA). These models were fitted to compare the theoretically growth of particles along with actual increase of particles size. Experimental results suggested that OA growth was originated in early phase, however, it substituted and mainly controlled by OR growth pattern over time.     

Dispersion and deposition mechanisms of particles suspended in a turbulent plane Couette flow

Inertial particle transfer in a turbulent plane Couette flow (C flow) was studied using Direct Numerical Simulation (DNS) of the flow combined with a Lagrangian particle tracking approach for particles with Stokes numbers (St) 5, 25 and 125. The particle concentration was assumed low enough, so that the simulations were done under one-way coupling condition.     

Determination of Some Transition Metals by Atomic Absorption Spectroscopy after Extraction with Pyridine-2-aldehyde-2-quinolylhydrazone

The extraction of pyridine-2-aldehyde-2-quinolylhydrazone chelates of cadmium, cobalt, copper, nickel, and zinc into isoamyl alcohol (IAOL) and methylisobutyl ketone (MIBK) has been investigated as a basis for the determination of these metals. Below pH 6 the extraction is enhanced by the addition of perchlorate, suggesting that charged complexes are being extracted by ion-pair formation. Sensitivities (1% absorption) are reported for IAOL and MIBK solutions of the metals sprayed into an air-acetylene flame. A procedure for the determination of the above metals by atomic absorption spectroscopy after extraction is given. The procedure is applied to the analysis of tap water for cadmium, copper, and zinc.     

Bio-inspired short peptide self-assembly: From particles to functional materials

Natural systems are typically featured with tremendous molecular complexity and construct exquisite architectures and functional materials through precise spatial and temporal control. Supramolecular self-assembly from peptides and proteins is believed to be the key player. Thus, knowledge of the fundamental mechanisms driving peptides into vast functional hierarchical structures will certainly help the rational control of self-assembly process, leading to more precise structural organization and functional optimization. In this review, we briefly summarize the recent progress of this burgeoning field mainly from two directions: peptide-based self-assembly and co-assembly with other functional molecules, each part is further divided into two subparts and representative examples are given for each subpart according to their development timeline. At the end of each part, brief summaries of the closely related applications are outlined. For the closing remarks, we conclude with our own understanding of the area and perspectives are given based on recent developments. Overall, this review could be suitable for both new readers to gain a comprehensive overview of the area and experienced readers to get a summary of the development in short peptide self-assembly from particles to functional materials.     

Particles in composite polymer electrolyte for solid-state lithium batteries: A review

Solid-state lithium batteries (SSLBs) have been identified as one kind of the most promising energy conversion and storage devices because of their safety, high energy density, and long cycling life. The development of solid-state electrolyte is vital to commercialize SSLBs. Composite polymer electrolyte (CPE), derived by compositing inorganic particles into solid polymer electrolyte has become the most practical species for SSLBs because it inherits the advantages of polymer electrolyte and simultaneously achieves enhanced ionic conductivity and mechanical properties. The characteristics of inorganic particles and their interaction with polymers strongly impact the performance of CPE, improving its ionic conductivity, mechanical properties, thermal and electrochemical stability, as well as interface compatibility with both electrodes. In this review, the effects of particle characteristics including its species, size, proportion, morphology on the ionic conductivity and mechanical properties of CPE are reviewed. Meanwhile, some novel composite strategies are also introduced including surface modification, hybridization, and alignment of particles in polymer matrices, as well as some new preparation methods of CPE. The interactions between particles and other components in CPE including polymer matrices or lithium salt are particularly focused herein to reveal the lithium conductive mechanism. Finally, a perspective on the direction of future CPE development for SSLBs is presented.     

Crystalline phase of Y_2O_3 :Eu particles generated in a substrate-free flame process

In this study, factors affecting the crystal structure of flame-synthesized Y 2 O 3 :Eu particles were inves- tigated, especially the particle size effect and its interaction with Eu doping concentration. Polydisperse Y 2 O 3 :Eu (size range 200 nm to 3 m) powder samples with Eu doping concentrations from 2.5 mol% to 25 mol% were generated in either H 2 /air or H 2 /O 2 substrate-free flames. The crystal structure of the powder samples was determined by powder X-ray diffraction (XRD), which was complemented...