Observation of localized magnetic plasmon skyrmions

Optical skyrmions have recently been constructed by tailoring vectorial near-field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we provide experimental demonstration of electromagnetic skyrmions based on magnetic localized spoof plasmons (LSP) showing large topological robustness against continuous deformations, without stringent external interference conditions. By directly measuring the spatial profile of all three vectorial magnetic fields, we reveal multiple π-twist target skyrmion configurations mapped to multi-resonant near-equidistant LSP eigenmodes. The real-space skyrmion topology is robust against deformations of the meta-structure, demonstrating flexible skyrmionic textures for arbitrary shapes. The observed magnetic LSP skyrmions pave the way to ultra-compact and robust plasmonic devices, such as flexible sensors, wearable electronics and ultra-compact antennas.

Possibilities and challenges for the shared management of solid waste in the Metropolitan Region of Natal (RN) considering Federal Law nº 12.305/2010

The National Solid Waste Policy emerged as a guideline for an environmental problem that was observed in Brazilian municipalities: the generation of solid waste combined with a prevalence of landfills. These problems largely became evident in metropolitan regions, which were characterized, among other aspects, by population concentration. Federal Law No. 12,305/2010 explicitly highlighted the issue of metropolitan management. The proposed study aimed to investigate the challenges for achieving the shared management of solid waste in the Metropolitan Region of Natal (RMN). To this end, documentary research and the systematization of secondary databases were undertaken, which enabled diagnostic research into the management of solid waste in the fifteen municipalities that make up the RMN. The study has revealed the difficulties in forming agreements between the municipal entities in the studied spatial profile, thereby influencing the outreach of an integrated management program in the RMN.

Third-order transport coefficients for electrons in N2 and CF4: effects of non-conservative collisions, concurrence with diffusion coefficients and contribution to the spatial profile of the swarm

Using a multi-term solution of the Boltzmann equation and Monte Carlo simulation technique we study behaviour of the third-order transport coefficients for electrons in model gases, including the ionisation model of Lucas and Saelee and modified Ness-Robson model of electron attachment, and in real gases, including N2 and CF4. We observe negative values in the E/n 0-profiles of the longitudinal and transverse third-order transport coefficients for electrons in CF4 (where E is the electric field and n 0 is the gas number density). While negative values of the longitudinal third-order transport coefficients are caused by the presence of rapidly increasing cross sections for vibrational excitations of CF4, the transverse third-order transport coefficient becomes negative over the E/n 0-values after the occurrence of negative differential conductivity. It is found that the accuracy of the two-term approximation for solving the Boltzmann equation is sufficient to investigate the behaviour of the third-order transport coefficients in N2, while for electrons in CF4 it produces large errors and is not even qualitatively correct . The influence of implicit and explicit effects of electron attachment and ionisation on the third-order transport tensor is investigated. In particular, we discuss the effects of attachment heating and attachment cooling on the third-order transport coefficients for electrons in the modified Ness-Robson model, while the effects of ionisation are studied for electrons in the ionisation model of Lucas and Saelee, N2 and CF4. The concurrence between the third-order transport coefficients and the components of the diffusion tensor, and the contribution of the longitudinal component of the third-order transport tensor to the spatial profile of the swarm are also investigated. For electrons in CF4 and CH4, we found that the contribution of the component of the third-order transport tensor to the spatial profile of the swarm between approximately 50 Td and 700 Td, is almost identical to the corresponding contribution for electrons in N2. This suggests that the recent measurements of third-order transport coefficients for electrons in N2 may be extended and generalized to other gases, such as CF4 and CH4.

Plasmodium SAS4/CPAP is a flagellum basal body component during male gametogenesis, but is not essential for parasite transmission

The centriole/basal body (CBB) is an evolutionarily conserved organelle acting as a microtubule organising centre (MTOC) to nucleate cilia, flagella and the centrosome. SAS4/CPAP is a conserved component associated with BB biogenesis in many model flagellated cells. Plasmodium, a divergent unicellular eukaryote and causative agent of malaria, displays an atypical closed mitosis with an MTOC, reminiscent of the acentriolar MTOC, embedded in the nuclear membrane at most proliferative stages. Mitosis during male gamete formation is accompanied by flagellum formation: within 15 minutes, genome replication (from 1N to 8N) and three successive rounds of mitosis without nuclear division occur, with coordinated axoneme biogenesis in the cytoplasm resulting in eight flagellated gametes. There are two MTOCs in male gametocytes. An acentriolar MTOC located with the nuclear envelope and a centriolar MTOC (basal body) located within the cytoplasm that are required for flagellum assembly. To study the location and function of SAS4 during this rapid process, we examined the spatial profile of SAS4 in real time by live cell imaging and its function by gene deletion. We show its absence during asexual proliferation but its presence and coordinated association and assembly of SAS4 with another basal body component, kinesin8B, which is involved in axoneme biogenesis. In contrast its separation from the nuclear kinetochore marker NDC80 suggests that SAS4 is part of the basal body and outer centriolar MTOC residing in the cytoplasm. However, deletion of the SAS4 gene produced no phenotype, indicating that it is not essential for male gamete formation or parasite transmission through the mosquito.

Simulation study of energetic-particle driven off-axis fishbone instabilities in tokamak plasmas

Kinetic-magnetohydrodynamic hybrid simulations were performed to investigate the linear growth and the nonlinear evolution of off-axis fishbone mode (OFM) destabilized by trapped energetic ions in tokamak plasmas. The spatial profile of OFM is mainly composed of m/n = 2/1 mode inside the q = 2 magnetic flux surface while the m/n = 3/1 mode is predominant outside the q = 2 surface, where m and n are the poloidal and toroidal mode numbers, respectively, and q is the safety factor. The spatial profile of the OFM is a strongly shearing shape on the poloidal plane, suggesting the nonperturbative effect of the interaction with energetic ions. The frequency of the OFM in the linear growth phase is in good agreement with the precession drift frequency of trapped energetic ions, and the frequency chirps down in the nonlinear phase. Two types of resonance conditions between trapped energetic ions and OFM are found. For the first type of resonance, the precession drift frequency matches the OFM frequency, while for the second type, the sum of the precession drift frequency and the bounce frequency matches the OFM frequency. The first type of resonance is the primary resonance for the destabilization of OFM. The resonance frequency which is defined based on precession drift frequency and bounce frequency of the nonlinear orbit for each resonant particle is analyzed to understand the frequency chirping. The resonance frequency of the particles that transfer energy to the OFM chirps down, which may result in the chirping down of the OFM frequency. A detailed analysis of the energetic ion distribution function in phase space shows that the gradient of the distribution function along the E′ = const. line drives or stabilizes the instability, where E′ is a combination of energy and toroidal canonical momentum and conserved during the wave-particle interaction. The distribution function is flattened along the E′ = const. line in the nonlinear phase leading to the saturation of the instability.

Cosmological particle production and pairwise hotspots on the CMB

Heavy particles with masses much bigger than the inflationary Hubble scale H*, can get non-adiabatically pair produced during inflation through their couplings to the inflaton. If such couplings give rise to time-dependent masses for the heavy particles, then following their production, the heavy particles modify the curvature perturbation around their locations in a time-dependent and scale non-invariant manner. This results into a non-trivial spatial profile of the curvature perturbation that is preserved on superhorizon scales and eventually generates localized hot or cold spots on the CMB. We explore this phenomenon by studying the inflationary production of heavy scalars and derive the final temperature profile of the spots on the CMB by taking into account the subhorizon evolution, focusing in particular on the parameter space where pairwise hot spots (PHS) arise. When the heavy scalar has an $$ \mathcal{O} $$ O (1) coupling to the inflaton, we show that for an idealized situation where the dominant background to the PHS signal comes from the standard CMB fluctuations themselves, a simple position space search based on applying a temperature cut, can be sensitive to heavy particle masses M0/H* ∼ $$ \mathcal{O} $$ O (100). The corresponding PHS signal also modifies the CMB power spectra and bispectra, although the corrections are below (outside) the sensitivity of current measurements (searches).

Stereolithographic Additive Manufacturing of Zirconia Electrodes with Dendritic Patterns for Aluminum Smelting

Zirconia electrodes with dendritic patterns were fabricated by stereolithographic additive manufacturing (STL-AM). A solid electrolyte of yttria-stabilized zirconia (YSZ) was selected for oxygen separation in the molten salt electrolysis of aluminum smelting without carbon dioxide excretion. Thereafter, 4, 6, 8 and 12-coordinated dendritic structures composed of cylindrical lattices were designed as computer graphics. The specific surface area of each structure was maximized by changing the aspect ratio. The spatial profile and surface pressure of the hot liquid propagation in the dendrite patterns were systematically visualized by computational fluid dynamics (CFD). During the fabrication process, a photosensitive resin containing zirconia particles was spread on a substrate, and an ultraviolet (UV) laser beam was scanned to create a two-dimensional (2D) cross-section. Through layer laminations, three-dimensional (3D) objects with dendritic structures were successfully fabricated. The ceramics were obtained through dewaxing and sintering.

Fashion industry in Brazil: Productive and spatial profile and the emergence of fashion law

This article addresses the Brazilian fashion industry's productive and spatial profile. The study demonstrates its importance and the need to move forward in constructing a new legal discipline with its own body of rules that regiment the complex relationships involving the creative process and its trade products. Therefore, we outline the Brazilian fashion industry profile and show the advances in several countries to define this new law's boundaries. Compared with the Brazilian case, we have concluded that despite the progress, the country is falling behind and in need of more firm actions to guarantee the legal security crucial to this industry's continued development.