Strange form factors in the context of SAMPLE, HAPPEX, and A4 experiments

The strange properties of the nucleon are investigated within the framework of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying the symmetry conserving SU(3) quantization. We present the form factors $G^0_{E,M}(Q^2)$, $G^Z_M(Q^2)$ and the electric and magnetic strange form factors $G^s_{E,M}(Q^2)$ incorporating pion and kaon asymptotics. The results show a fairly good agreement with the recent experimental data from the SAMPLE and HAPPEX collaborations. We also present predictions for future measurements including the A4 experiment at MAMI (Mainz).Comment: 10 pages with four figures. RevTeX4 is used. Few lines are changed. Accepted for publication in Phys.Rev.

TiO2-MWCNT Nanohybrid: Cytotoxicity, protein corona formation and cellular internalisation in RTG-2 fish cell line

Titanium dioxide nanoparticles-multiwalled carbon nanotubes (TiO2-MWCNT) nanohydrid has an enhanced photocatalytic activity across the visible light with promising applications in environmental remediation, solar energy devices and antimicrobial technologies. However, it is necessary to evaluate the toxicological effects of TiO2-MWCNT towards safe and sustainable development of nanohybrids. In this work, we studied the cytotoxicity, protein corona formation and cellular internalisation of TiO2-MWCNT on fibroblasts derived from gonadal rainbow trout tissue (RTG-2) for the first time. This nanohydrid did not show any toxicity effect on RTG-2 cells up to 100 mg L-1 after 24 h of exposure as monitored by alamar blue, neutral red and trypan blue assays (in presence or absence of foetal bovine serum, FBS). Futhermore, cryo-transmission electron microscopy analysis demonstrated that TiO2 particles is attached on nanotube surface after FBS-protein corona formation in cell culture medium. Raman spectroscopy imaging showed that TiO2-MWCNT can be internalised by RTG-2 cells. This work is a novel contribution towards better understanding the nanobiointeractions of nanohydrids linked to their in vitro effects on fish cells in aquatic nanoecotoxicology

Strange nucleon form factors in the perturbative chiral quark model

We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the form factors is presented.Comment: 18 pages, 6 figure

Eruptions of Magnetic Ropes in Two Homologous Solar Events on 2002 June 1 and 2: a Key to Understanding of an Enigmatic Flare

The goal of this paper is to understand the drivers, configurations, and scenarios of two similar eruptive events, which occurred in the same solar active region 9973 on 2002 June 1 and 2. The June 2 event was previously studied by Sui, Holman, and Dennis (2006, 2008), who concluded that it was challenging for popular flare models. Using multi-spectral data, we analyze a combination of the two events. Each of the events exhibited an evolving cusp-like feature. We have revealed that these apparent ``cusps'' were most likely mimicked by twisted magnetic flux ropes, but unlikely to be related to the inverted Y-like magnetic configuration in the standard flare model. The ropes originated inside a funnel-like magnetic domain whose base was bounded by an EUV ring structure, and the top was associated with a coronal null point. The ropes appear to be the major drivers for the events, but their rise was not triggered by reconnection in the coronal null point. We propose a scenario and a three-dimensional scheme for these events in which the filament eruptions and flares were caused by interaction of the ropes.Comment: 22 pages, 11 figure

Lagochilascariasis leading to severe involvement of ocular globes, ears and meninges

A case report of a 31 year-old woman from Paraíba State (North-Eastern Brazil) that presented severe involvement of ocular globes, ears and meninges. Diagnosis was established after enucleation of her left eye, when adult worms were seen in the midst of a granulomatous inflammatory process. Her response to the initial treatment with levamisole and cambendazole was good, but there was a relapse after the fifth month of treatment even with maintenance doses of both medications. She later received ivermectin and albendazol and responded well.Paciente do sexo feminino, com 31 anos, procedente da Paraíba, apresentava envolvimento severo de ambos os globos oculares, com perda da visão à esquerda, comprometimento da audição e das meninges. Após enucleação do olho esquerdo fragmento de helminto identificado como Lagochilascaris minor foi observado em processo inflamatório granulomatoso. Inicialmente a paciente foi tratada com levamisol e cambendazol, com bom resultado. Verificou-se, todavia, piora do quadro após cinco meses, com eliminação de larvas do ascarídeo em lesão presente na órbita esquerda, embora a medicação fosse mantida com administração periódica. Houve boa resposta terapêutica, com regressão do quadro, após substituição dos anti-helmínticos anteriores pela associação ivermectina e albendazol

Bibliometric analysis on the use of natural fibers in construction materials

Received: February 2nd, 2021 ; Accepted: August 3rd, 2021 ; Published: August 30th, 2021 ; Correspondence: [email protected] to the increasing interest of the population in the sustainability theme, there was a consequent growth in publications related to the theme in the area of civil construction. Agroindustrial waste has become an environmental problem, and with that natural fibers have found space in the reuse of waste due to its characteristics and possibilities of improving the mechanical properties of its products. In order to achieve sustainable construction demand, along with the need to reuse waste, studies have begun to analyze the application of natural fibers in construction materials. The documents provided by the Web of Science (WOS) database through research carried out with the search for the terms ‘Natural Fibers’ and ‘Building materials’ restricted to the period 2010–2020 in the main WOS collection. The institutions involved with the publications, the countries of origin of the documents, the year of publication, the keywords used by the authors and the number of citations for each document were analyzed using bibliometrics in the VOSVIEWER (VOS) software. The result of the analysis shows an increase in documents related to the theme over the years, and that the countries with the most studies in the area are China (16), USA (14) and Brazil (11), respectively. The results presented after analysis of the keywords show that natural fiber (61 occurrences), mechanical properties (44 occurrences) and composites (31 occurrences) are the words with the highest occurrence among the analyzed documents. The present study shows the growth of research related to the theme, in addition to discriminating countries, institutions and authors, which allows monitoring the scientific expansion of the theme and guiding future studies

Robust leakage-based distributed precoder for cooperative multicell systems

Coordinated multipoint (CoMP) from long term evolution (LTE)-advanced is a promising technique to enhance the system spectral efficiency. Among the CoMP techniques, joint transmission has high communication requirements, because of the data sharing phase through the backhaul network, and coordinated scheduling and beamforming reduces the backhaul requirements, since no data sharing is necessary. Most of the available CoMP techniques consider perfect channel knowledge at the transmitters. Nevertheless for practical systems this is unrealistic. Therefore in this study the authors address this limitation by proposing a robust precoder for a multicell-based systems, where each base station (BS) has only access to an imperfect local channel estimate. They consider both the case with and without data sharing. The proposed precoder is designed in a distributed manner at each BS by maximising the signal-to-leakage-and-noise ratio of all jointly processed users. By considering the channel estimation error in the design of the precoder, they are able to reduce considerably the impact of these errors in the system's performance. The results show that the proposed scheme has improved performance especially for the high signal-to-noise ratio regime, where the impact of the channel estimation error may be more pronounced

Chiral phase boundary of QCD at finite temperature

We analyze the approach to chiral symmetry breaking in QCD at finite temperature, using the functional renormalization group. We compute the running gauge coupling in QCD for all temperatures and scales within a simple truncated renormalization flow. At finite temperature, the coupling is governed by a fixed point of the 3-dimensional theory for scales smaller than the corresponding temperature. Chiral symmetry breaking is approached if the running coupling drives the quark sector to criticality. We quantitatively determine the phase boundary in the plane of temperature and number of flavors and find good agreement with lattice results. As a generic and testable prediction, we observe that our underlying IR fixed-point scenario leaves its imprint in the shape of the phase boundary near the critical flavor number: here, the scaling of the critical temperature is determined by the zero-temperature IR critical exponent of the running coupling.Comment: 39 pages, 8 figure

Calibration of the length of a chain of single gold atoms

Using a scanning tunneling microscope or mechanically controllable break junctions it has been shown that it is possible to control the formation of a wire made of single gold atoms. In these experiments an interatomic distance between atoms in the chain of ~3.6 Angstrom was reported which is not consistent with recent theoretical calculations. Here, using precise calibration procedures for both techniques, we measure length of the atomic chains. Based on the distance between the peaks observed in the chain length histogram we find the mean value of the inter-atomic distance before chain rupture to be 2.6 +/- 0.2 A . This value agrees with the theoretical calculations for the bond length. The discrepancy with the previous experimental measurements was due to the presence of He gas, that was used to promote the thermal contact, and which affects the value of the work function that is commonly used to calibrate distances in scanning tunnelling microscopy and mechanically controllable break junctions at low temperatures.Comment: 6 pages, 6 figure