In this paper, we theoretically investigate the dynamics and stability of matter‐wave solitons (MWS) in a cigar‐shaped Bose–Einstein condensate (BEC) consisting of atoms with attractive interatomic ...interactions trapped by Pöschl–Teller (PT) potential. In this scenario, we propose the idea of the BEC being dragged by PT potential at a constant speed. The BEC was modeled by the quasi‐one‐dimensional Gross–Piteaevskii Equation (1D‐GPE). In addition, an analytical (time‐dependent variational method) and numerical (split‐step Crank–Nicolson method) approach has been proposed to investigate the dynamic properties of solitons during the temporal evolution of this system. Both analytical and numerical results demonstrated that MWSs dragged by PT potential can be stable. From a general point of view, the results obtained in this paper can motivate both theoretical and experimental investigations on the dynamics and stability of solitons in dilute and ultracold unitary Bose gases trapped by PT potential, nonlinear optical properties in PT quantum wells, and propagation of solitons in nonlinear media.
The dynamic behavior of matter‐wave solitons in cigar‐shaped Bose‐Einstein condensates confined by the Pöschl–Teller potential was studied. The model proposed in this paper was described by the one‐dimensional Gross–Pitaevskii equation within the scope of the mean‐field theory. Numerical and variational solutions demonstrated that attractive Bose–Einstein condensates can be stable during the dragging of the Pöschl–Teller potential.
Gold nanoparticles (AuNPs) have shown interesting properties and specific biofunctions, providing benefits and new opportunities for controlled release systems. In this research, we demonstrated the ...use of natural rubber latex (NRL) from Hevea brasiliensis as a carrier of AuNPs and the antibiotic metronidazole (MET). We prepared AuNP-MET-NRL and characterized by physicochemical, biological and in vitro release assays. The effect of AuNPs on MET release was evaluated using UV–Vis and Laser-Induced Breakdown Spectroscopy (LIBS) techniques. AuNPs synthesized by Turkevich and Frens method resulted in a spherical shape with diameters of 34.8 ± 5.5 nm. We verified that there was no emergence or disappearance of new vibrational bands. Qualitatively and quantitatively, we showed that the MET crystals dispersed throughout the NRL. The Young's modulus and elongation values at dressing rupture were in the range appropriate for human skin application. 64.70% of the AuNP-MET complex was released within 100 h, exhibiting a second-order exponential release profile. The LIBS technique allowed monitoring of the AuNP release, indicating the Au emission peak reduction at 267.57 nm over time. Moreover, the dressing displayed an excellent hemocompatibility and fibroblast cell viability. These results demonstrated that the AuNP-MET-NRL wound dressing is a promising approach for dermal applications.
•A wound dressing was developed using AuNPs and metronidazole loaded into NRL.•The reduction of the Au signal verified by LIBS proved to be an efficient approach in the identification of AuNP released•64.7% of the AuNPs-metronidazole complex was released by the polymeric matrix•Wound dressing was biocompatible in hemolytic tests, beyond to contributing to the fibroblasts proliferation.
The biofilm accumulation over the composite resin restorations can contribute to the formation of secondary caries. In this way, antibacterial restorative composite resins are highly desired. Then, ...the purpose of this study was to modify a composite resins using Ag doped ZnO nanoparticles (NPs), evaluate the antibacterial and mechanical properties of the modified composite resin. The ZnO/AgNPs were synthesized by two different routes, polymeric precursor and coprecipitation methods, and characterized by thermal decomposition, X-ray diffraction, specific surface area by N
desorption/desorption and scanning electron microscopy (SEM). Antibacterial activity of composite resin specimens (4 mm in height and 2 mm in diameter; n = 15) modified by ZnO/Ag nanoparticles was performed against 7-days Streptococcus mutans biofilm. Colony forming units (CFU/mL) were used to evaluate the bacterial activity. Additionally, the morphology and the bacteria adherence area were analyzed by SEM images. Cylindrical specimens (6 mm in height and 4 mm in diameter; n = 20) of the composite resin containing ZnO/Ag NPs were prepared to perform compressive strength in a universal mechanical test machine, and the surface of fractured specimens was analyzed by EDX element mapping to verify NPs homogeneity. The normal distribution was confirmed and the two-way analysis of variance (ANOVA) and Tukey's test for pair comparison were performed. The nanospheres of ZnO/Ag lead to a better biofilm inhibition, than nanoplates. No difference on compressive strength was found for the composite resin modified by ZnO/Ag nanoplates. Based on these results, this material could be a good option as a new restorative material.
Sistemas Tutores Inteligentes têm se destacado como ferramenta de apoio ao ensino, principalmente pela sua adaptação às condições do usuário e cenário de aplicação. Diante da situação pandêmica, as ...ferramentas de apoio ao ensino, como os tutores, devido a sua viabilidade de utilização remota, mostram-se como uma possibilidade de suporte aos professores e alunos. Este trabalho aborda uma proposta de adaptação de conteúdo para ensino, aplicando técnicas de inteligência artificial para geração de texto e processamento de linguagem natural. Além disso, este trabalho considerou a existência de diferentes estilos de aprendizagem, variáveis conforme a personalidade do estudante e seu modo de captar informação, capaz de influenciar no nível de aprendizado. Esta variação de estilos, seguindo um modelo definido na literatura, direciona o modo de adaptação do conteúdo a ser realizado, gerando um resultado adaptado a cada estilo de aprendizagem.O processo de geração de conteúdo personalizado permite um avanço na forma de uso de sistemas tutores no ensino, criando um formato de entrega direcionada de conteúdo com ganhos para o usuário do ambiente, gerando um resultado personalizado e conduzindo a uma aprendizagem mais efetiva. Como resultado se espera obter uma metodologia para geração de conteúdo baseados em estilos de aprendizagem pré-definidos, por meio de processamento automatizado de adaptação do conteúdo a partir de entrada inicial em formato único.
Recently, studies on climate change have highlighted the central role of photosynthetic mechanisms in the defense response of plants to abiotic and biotic stresses. Photo-sensing and photo-activation ...are innovative technologies applied for the early detection of plant pathogens in order to prevent the dramatic impact they may have on plants. Chlorophyll Fluorescence Imaging (CFI) and Laser-Induced Breakdown Spectroscopy (LIBS) analytical techniques can be used to evaluate the amount of chlorophyll in plants, which can be altered in the case of biotic and abiotic stresses. In this work, both techniques were applied to two pathogenic model systems, i.e., roots of susceptible tomato plants infected by Meloidogyne incognita and Nicotiana benthamiana plants infected by cymbidium ringspot virus. Experimental evidence is provided and discussed showing that specific application protocols of both methods can be used successfully for the early detection of symptoms of the pathogen attacks of Meloidogyne incognita on tomato roots and of cymbidium ringspot virus infected plants. In particular, a decrease in chlorophyll content was measured by fluorescence imaging, and an increase in Mgsup.++ content was determined by LIBS in both the leaves and stems of infected tomato plants and the leaves of infected plants, with respect to control (non-infected) plants. Thus, the two techniques used have been shown to be able to discriminate satisfactorily between control and infected plants and to provide some insight on the underlying mechanisms of plant defenses again nematodes and viruses.
In recent years there has been a growing interest in the study of hospitality as a social phenomenon. This interest has tended to arrive from two communities. The first comprises hospitality ...academics interested in exploring the wider meanings of hospitality as a way of better understanding guest and host relations and its implications for commercial settings. The second comprises social scientists using hosts and guests as a metaphor for understanding the relationship between host communities and guests as people from outside the community - migrants, asylum seekers and illegal immigrants.
The Routledge Handbook of Hospitality Studies encourages both the study of hospitality as a human phenomenon and the study for hospitality as an industrial activity embracing the service of food, drink and accommodation. Developed from specifically commissioned original contributions from recognised authors in the field, it is the most up-to-date and definitive resource on the subject. The volume is divided into four parts: the first looks at ways of seeing hospitality from an array of social science disciplines; the second highlights the experiences of hospitality from different guest perspectives; the third explores the need to be hospitable through various time periods and social structures, and across the globe; while the final section deals with the notions of sustainability and hospitality. This handbook is interdisciplinary in coverage and is also international in scope through authorship and content. The 'state-of-the-art' orientation of the book is achieved through a critical view of current debates and controversies in the field as well as future research issues and trends. It is designed to be a benchmark for any future assessment of the field and its development.
This handbook offers the reader a comprehensive synthesis of this discipline, conveying the latest thinking, issues and research. It will be an invaluable resource for all those with an interest in hospitality, encouraging dialogue across disciplinary boundaries and areas of study.
A compreensão da dinâmica dos movimentos contemporâneos de reestruturação de espaços urbanos é fundamental para o entendimento dos processos de ressignificação do ambiente construído, em especial em ...áreas urbanas nas quais a edificação se pode transformar, reconhecidamente, em um objeto cultural, colaborando para o aumento do valor do entorno. Nesse sentido, devem ser vistos os edifícios não a partir de uma visão reducionista, mas desde um ponto de vista amplo e totalizante: como produtos imobiliários e como artefatos arquitetônicos, dotados de valor material, social e simbólico. Como artefatos, poderiam colaborar para a ressignificação dos espaços urbanos por meio da reconfiguração dos espaços internos e do próprio redesenho da edificação, bem como por sua relação com o entorno, a partir da dialética entre a estrutura material edificada e a sociedade. Como produtos imobiliários, poderiam inserir-se de uma maneira inovadora no circuito de valorização do capital, firmando-se como mercadorias diferenciadas e orientando a própria sobrevida e expansão do capitalismo em ambiente urbano. A dinâmica socioespacial e as características do capitalismo contemporâneo levam a um movimento de reestruturação imobiliária, processo complexo e amplo, que se dá em dois níveis: a reestruturação espacial (novas formas e funções do imóvel e a revisão de seu papel estruturante junto à sociedade e ao espaço) e a reestruturação produtiva (novas maneiras de construir e administrar o produto imobiliário). Este texto está baseado na interpretação da produção imobiliária voltada para fins específicos e usos determinados, neste caso, para os edifícios hoteleiros instalados em importantes destinos do circuito mundial de viagens. Tem como objetivo maior orientar a apreensão dos novos sentidos e significados do ambiente construído e de sua adequação aos processos de valorização do capital e de reestruturação dos espaços urbanos contemporâneos.
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