Probing the Molecular Ordering in Azopolymer Thin Films by Second-Order Nonlinear Optics

Second-harmonic generation (SHG), a second-order nonlinear optical technique, was used to investigate the molecular ordering of self-assembled layer-by-layer films of PAH, a cationic polyelectrolyte, and PS-119, an anionic polyelectrolyte containing photoisomerizable azo groups. Possible phase transitions in these multilayer films and their thermal stability were investigated by probing the SHG signal as a function of temperature and comparing the molecular order before and after thermal treatment. These studies were also performed with different pH values for the assembling solutions, a relevant parameter for polyelectrolyte adsorption. The results have shown that the films are not thermally stable, with the SHG signal nearly vanishing at a temperature of 150°C, in contrast to what is reported in the literature. SHG measurements have also confirmed that the films are isotropic in the plane of the samples, independent of their number of layers or the pH of assembling solutions. SHG signal before and after heating indicates that the SHG signal was considerably reduced at high temperatures, but after slow cooling it was recovered to almost the same value as before heating, showing that the thermal disorder is reversible. No phase transition was observed, since the SHG signal reduction was slow and gradual, without any sudden change that would characterize a glass transition. We demonstrate that the SHG technique provides information on the film arrangement at the microscopic level which could be difficult to get with traditional techniques

Online Construction of Wavelet Trees

The wavelet tree (WT) is a flexible and efficient data structure for representing character strings in succinct space, while allowing for fast generalised rank, select and access operations. As such, they play an important role in modern text indexing methods. However, despite their popularity, not many algorithms have been published concerning their construction. In particular, while the WT is capable of representing a sequence of length n over an alphabet of size m in nlg m+o(nlg m) bits, much more space is typically used for its construction. Here we propose an O(nlg m)-time online method for the construction of the WT, requiring no prior knowledge about the input alphabet. The proposed algorithm is conceptually simpler than other state-of-the-art methods, while having comparable time performance and being more space-efficient in practice, since it performs just one pass over the input text and uses little extra space other than for the structure itself, as shown both theoretically and empirically

Influence of moisture content and gaps on the withdrawal resistance of self tapping screws in CLT

Self-tapping screws (STS) have been proclaimed as the easiest solution for structural timber connections, in special for cross laminated timber (CLT) constructions. In order to understand deeply the composite model “CLT-STS”, an experimental campaign which comprised 270 withdrawal tests was carried out. Maximum withdrawal load capacity of self-tapping screws inserted in plane side of a three layered CLT panel was evaluated considering three main parameters: moisture levels of CLT (i), number of gaps (ii) and the width of gaps (iii). Regarding (i), connections were tested with CLT at 8%, 12% and 18% of moisture content. Concerning (ii) and (iii), different test configurations with 1, 2 and 3 gaps, with 0 or 4mm, were tested. The influences of moisture content and number of gaps were modeled. Further a correlation between test results and a prediction model developed by Uibel and Blaß (2007) has been proposed

The Relationship between Elementary Chemical Composition and Extraction Method for Protium Strumosum Daly Species Resin

The genus Protium Burm f., the most abundant of the Burseraceae family, has its primary center of diversity in the Amazon. Its main characteristic is the exudation of “Breu”, an aromatic resin collected directly from the trunk of the trees.Stimulating pastes have been used to increase resin flow, such as 2-chloroethylphosphonic (Ethephon). It is important to evaluate variations in the composition of the resin extracted naturally and with the use of the stimulant, to guarantee the product quality. The inorganic analysis is also fundamental to verify the presence of compounds harmful to health.A quali-quantitative elemental variation of the resin between the two extraction modes was proved by WD-XRF analysis. In 15 samples, Mg and F were only observed in those using Ethephon. In samples from the same tree, the qualitative difference is 54%, proving a discrepancy in the chemical composition of Breu, which can alter its properties

Hemispheric asymmetry in the sunspot cycle as a nonextensive phenomenon

The appearance of dark sunspots over the solar photosphere is not considered to be symmetric between the northern and southern hemispheres. Among the different conclusions obtained by several authors, we can point out that the North-South asymmetry is a real and systematic phenomenon and is not due to random variability. In the present work, we selected the sunspot area data of a sample of 13 solar cycles divided by hemisphere extracted from the Marshall Space Flight Centre (MSFC) database to investigate the behavior of probability distributions using an out-of-equilibrium statistical model a.k.a non-extensive statistical mechanics. Based on this statistical framework, we obtained that the non-extensive entropic parameter $q$ has a semi-sinusoidal variation with a period of $\sim$22 year (Hale cycle). Among the most important results, we can highlight that the asymmetry index $q(A)$ revealed the dominance of the northern hemisphere against the southern one. Thus, we concluded that the parameter $q(A)$ can be considered an effective measure for diagnosing long-term variations of the solar dynamo. Finally, our study opens a new approach to investigating solar variability from the nonextensive perspective.Comment: 17 pages, 2 tables and 5 figures. Submitted to Solar Physic

Finding bichromatic-bidirectional waves with ADVS

The aim of this study is to investigate Bichromatic-Bidirectional waves to characterize the subtractive wave-wave nonlinear interactions, using adaptive techniques rather than traditional spectral techniques. A physical model test in a 3D-wave basin was conducted and measurements were made with two arrays of ultrasonic sensors of free surface and one array of ADVs. The Hilbert-Huang transform, aided by the Multivariate Empirical Mode Decomposition, was applied to the orbital velocity data and the main characteristics of the infragravity wave (velocity amplitude, period and direction) were extracted with a good precision. © 2018 American Society of Civil Engineers (ASCE). All rights reserved

Pregnancy after uterine arterial embolization

OBJECTIVE: To evaluate pregnancy outcomes, complications and neonatal outcomes in women who had previously undergone uterine arterial embolization. METHODS: A retrospective study of 187 patients treated with uterine arterial embolization for symptomatic uterine fibroids between 2005-2008 was performed. Uterine arterial embolization was performed using polyvinyl alcohol particles (500-900 mm in diameter). Pregnancies were identified using screening questionnaires and the study database. RESULTS: There were 15 spontaneous pregnancies. Of these, 12.5% were miscarriages (n = 2), and 87.5% were successful live births (n = 14). The gestation time for the pregnancies with successful live births ranged from 36 to 39.2 weeks. The mean time between embolization and conception was 23.8 months (range, 5-54). One of the pregnancies resulted in twins. The newborn weights (n = 14) ranged from 2.260 to 3.605 kg (mean, 3.072 kg). One (7.1%) was considered to have a low birth weight (2.260 kg). There were two cases of placenta accreta (12.5%, treated with hysterectomy in one case [6.3%]), one case of premature rupture of the membranes (PRM) (6.3%), and one case of preeclampsia (6.3%). All of the patients were delivered via Cesarean section. CONCLUSION: In this study, there was an increased risk of Cesarean delivery. There were no other major obstetric risks, suggesting that pregnancy after uterine arterial embolization is possible without significant morbidity or mortality

Xyloglucan and Concanavalin A based dressings in the topical treatment of mice wound healing process

For medical biomaterials, xyloglucan dispersions can form films or gels to be applied as a wound dressing. For this purpose, the structural characterization of xyloglucan dressing (XG) and xyloglucan dressing containing 0.5 mg/mL of concanavalin A (XGL) was performed. The lectin release capacity and stability, cytotoxicity, and pro-wound healing effects were also investigated. XG and XGL films were prepared by mixing 0.5 % (w/v) xyloglucan with 0.3 % (v/v) glycerol. The ConA incorporated in the xyloglucan dressing maintained its biological activity for fourteen days in a controlled-release manner. The films were non-toxic, homogeneous, flexible, and accelerated the wound contraction compared with the control group, promoting less infiltration of inflammatory cells, angiogenesis, remodeling, and early epithelization. The films also alleviate the inflammation phase by reducing the production of pro-inflammatory cytokines (IFN-, TNF-, IL-1, IL-6, and IL-12), especially the XGL film, which promoted the up- and down-regulation of important proteins associated with the wound repair. All these findings suggest that XG and XGL films may represent a good therapeutic approach for wound healing applications.The authors are grateful for the financial support for research grants from the Conselho Nacional de Desenvolvimento Científico e Tecnol ´ogico (CNPq), Coordenaç˜ao de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and the Fundaç˜ao de Amparo `a Ciˆencia e Tecnologia do Estado de Pernambuco (FACEPE). We are grateful to the Centro de Tecnologias Estrat´egicas do Nordeste (CETENE) and to the Laborat´orio de Imunopatologia Keizo Asami-LIKA at the Universidade Federal de Pernambuco (UFPE) for access to its installation and technical assistance.info:eu-repo/semantics/publishedVersio