São Paulo Federal Institute of Education, Science and Technology

About: São Paulo Federal Institute of Education, Science and Technology is a education organization based out in São Paulo, Brazil. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1707 authors who have published 2374 publications receiving 11333 citations.

Anisotropic flux penetration in superconducting Nb films with frozen-in in-plane magnetic fields

Abstract: The magnetic anisotropy of superconducting niobium films of different thickness was investigated using magneto-optical imaging. A wide range of anisotropic behaviors was generated by freezing in different in-plane external magnetic fields with magnitude up to 1.12 kOe. The critical fields for the parallel configuration of the different samples were calculated, taking into account the strong deviation of the superconducting properties at small thicknesses. Above their lower in-plane critical field, the films are in the mixed state containing coplanar vortices. In structurally isotropic Nb films, when applying a perpendicular magnetic field, the frozen-in vortices were seen to guide the perpendicular ones. It is shown that the anisotropy increases with both the film thickness and the magnitude of the in-plane field. The results demonstrate that the field-induced anisotropy is a highly versatile way to manipulate vortex matter in film superconductors.

Unsteady State Heat Transfer in Packed-Bed Elliptic Cylindrical Reactor: Theory, Advanced Modeling and Applications

Abstract: Transport phenomena through porous media has been of continuing interest for scientists, researchers and engineers due to the wide range of industrial applications. This chapter presents information about unsteady-state heat transfer and fluid flow inside of packed-bed reactors. The topics covered are related to fundamentals of porous media, chemical reactors, including mathematical modeling and applications. Emphasis is placed on packed-bed elliptic-cylindrical reactor. Based on the concept of local thermal equilibrium, a general mathematical formulation for a pseudo-homogeneous heat transfer model written in elliptic-cylindrical coordinates along with the numerical solution of the governing equation has been presented. Herein, an overview of currently-used models and the pertinent transient conductive transport processes inside the reactor were explored. A numerical example of heat transfer and fluid flow in a multiphase system (elliptic-cylindrical reactor filled with particles) was performed, and results of the temperature distribution inside the equipment at different instant of process are presented and discussed.

A Fuzzy Intrusion Detection System for Identifying Cyber-Attacks on IoT Networks

Abstract: The Internet of Things (IoT) is increasingly present in our daily activities, connecting the most varied types of physical devices present around us to the internet. IoT is the basis for smart cities, e-health, precision agriculture, among others. With this growth, the number of cyber-attacks against these types of devices and services has also increased. Each type of attack has its specific characteristics that allow its identification and prevention through machine learning techniques. However, classic machine learning techniques may have their performance compromised due to the non-stationary characteristics of these environments, together with the search for different types of vulnerabilities by attackers, attacks can suffer different types of mutations, in addition to the great possibility of new types of attacks arising over time. In this article, we propose an algorithm called Fuzzy Intrusion Detection System for IoT Networks (FROST) to identify cyber-attacks on IoT networks. FROST uses the concepts of fuzzy set theory to make the learning task more flexible, seeking to improve the performance in the classification of inaccurate data. In addition, FROST has a mechanism for identifying new types of intrusion online, during the classification of new instances. To evaluate our approach, we used the UNSW-NB15 data set and compared our method with another approach, very consolidated in the literature, which performs the same type of task. The results showed that FROST has a good performance in the classification of different types of attacks and that the fuzzy technique used helped to reduce errors and identify anomalies.

Densidade, distância, divisão e as redes de produção globais: o caso do setor brasileiro de petróleo e gás

Abstract: Resumo Alem de fomentar o aumento do comercio entre paises, a globalizacao tem mudado significativamente os processos economicos ao possibilitar que as empresas dividam as cadeias de producao e comercializacao em varios segmentos, que se espalham por todo o mundo. Nesse sentido, as redes de producao globais (RPGs), fragmentadas organizacionalmente e dispersas espacialmente, tem se constituido em uma nova estrutura que impulsiona cada vez mais a economia mundial. Partindo dos conceitos de densidade, distância e divisao, considerados pelo Relatorio de Desenvolvimento Mundial do Banco Mundial de 2009 como fatores determinantes para se forjar o desenvolvimento regional, este artigo objetiva analisar a maneira pela qual o setor de petroleo e gas no Brasil tem se conectado as RPGs, as condicoes que beneficiam e dificultam essas conexoes, e as implicacoes disso para o desenvolvimento regional.

Encapsulation of the Sulfur Compounds by Cucurbit[7]uril: A Quantum Chemistry Study.

Abstract: Benzothiophene (BT) and dibenzothiophene (DT) are the most important contaminants in the petroleum derivatives responsible for serious environmental and health problems. Therefore, we have investigated the absorption of these compounds for the first time by considering cucurbit[7]uril (CB[7]) as the host molecule and using the theoretical levels of density functional theory//B3LYP-D3/6-31G(d). BT and DT absorbed into CB[7] do not undergo a significant structural change in the CB[7] structure. The energy gap of the S-compounds@CB[7] in water and hexane solvents was approximately 5 eV, and this large value implies that the complexes have high chemical stability. Moreover, the absorption of the BT and DT into CB[7] in the water and hexane solvents is a favorable process, whereas the lowest binding energy was observed between the dibenzothiophene and CB[7] in the DT@CB[7] complex. The solvation enthalpy shows a preferential solvation of the complexes in water than in hexane solvent. This trend is confirmed by...