Implementação em FPGA de módulo de efeito de reverberação

Reverberation is caused by the reflection of the sound in adjacent surfaces close to the sound source during its propagation to the listener. The impulsive response of an environment represents its reverberation characteristics. Being dependent on the environment, reverberation takes to the listener characteristics of the space where the sound is originated and its absence does not commonly sounds like “natural”. When recording sounds, it is not always possible to have the desirable characteristics of reverberation of an environment, therefore methods for artificial reverberation have been developed, always seeking a more efficient implementations and more faithful to the real environments. This work presents an implementation in FPGAs (Field Programmable Gate Arrays ) of a classic digital reverberation audio structure, based on a proposal of Manfred Schroeder, using sets of all-pass and comb filters. The developed system exploits the use of reconfigurable hardware as a platform development and implementation of digital audio effects, focusing on the modularity and reuse characteristics

Políticas públicas de economia solidária: uma avaliação do PCPR II na microrregião de Angicos do Rio Grande do Norte

The Solidarity Economy is considered in this work as a development option. Talk about it is to think in the workforce as a producer of material wealth and, above all , subjective , therefore it is necessary to take into account that these relations coexist different types of practices that encompass emotions , lifestyles , etc. This research has as an object of study evaluating the effectiveness of public policy for Solidarity Economy, microrregion Angicos / RN, demonstrating how the Solidarity Economy has encouraged the development not only as a driving force for economic growth, but as the expansion capabilities and freedoms. The Solidarity Economy has several definitions, and despite having its origin in the cooperative movement, is a concept under construction. Focused on the discussion of public policy, is now understood as a proposal for employability, either as a generator of employment and income, reflecting its polymorphism. Theories and concepts developed by Amartya Sen is an important analytical tool for understanding the Solidarity Economy as a development strategy. When speaking of instrumental freedoms, Senniana theory contributes to reflection on how participants socioeconomic actions are becoming active agents of change i n their own freedoms. The analysis was based on the discussion of development beyond economic bias, using the lines of the vari ous local stakeholders with PCPR II, p hase 2, for microrregion Angicos / RN, comprising: public managers, technical advisors and beneficiaries of the program rural poverty alleviation. Besides the discussion of the economic organization of the RN and its spatial distribution, the survey brings the result that the Solidarity Economy in microrregion Angicos / RN contributed to the dev elopment as freedom, proving the effectiveness of public policy by allowing an improvement in the quality of life, enabling efetivations, even without major proportions.

Encapsulamento de solventes em nanotubos de haloisita para promoção de auto-reparo em polímeros

Micro cracking during service is a critical problem in polymer structures and polymer composite materials. Self-healing materials are able to repair micro cracks, thus their preventing propagation and catastrophic failure of structural components. One of the self-healing approaches presented in the literature involves the use of solvents which react with the polymer. The objective of this research is to investigate a procedure to encapsulate solvents in halloysite nanotubes to promote self-healing ability in epoxy. Healing is triggered by crack propagation through embedded nanotubes in the polymer, which then release the liquid sovent into the crack plane. Two solvents were considered in this work: dimethylsulfoxide (DMSO) and nitrobenzene. The nanotubes were coated using the layer-by-layer technique of oppositely charged polyelectrolytes: cetyltrimethylammonium bromide (CTAB) and sodium polyacrylate. Solvent encapsulation was verified by X-ray diffraction (XRD), Fourier transform infrared (FTIR), analysis thermogravimetry (TGA), adsorption and desorption of nitrogen and scanning electron microscopy (SEM). The introduction of the solvent DMSO into the cavity of the nanotubes was confirmed by the techniques employed. However, was not verified with nitrobenzene only promoted clay aggregation. The results suggest that the CTAB reacted with the halloystite to form a sealing layer on the surface of the nanotubes, thus encapsulating the solvent, while this was not verified using sodium polyacrylate.

Alquilação de tolueno com propeno, através de complexo ferro (II) ᵦ- diimina homogêneo e heterogeneizado em MCM-41, Al-MCM-41 e SBA-15

This work describes the synthesis and aplication of homogeneous and heterogenized iron catalysts in the alkylation reaction of toluene with propene, empolying experimental design. The homogenous complex was obtained trough the synthesis of the organic ligand folowed by the complexation of the iron(II) chloride. As to the heterogenized complexes, first were synthetized the inorganic supports (SBA-15, MCM-41 and Al-MCM-41). Then, it was synthetized the ligand again, that through funcionalization with chloropropyltrimethoxysilane (CPTMS), was anchored on the support previously calcinated. To these anchored ligands, was complexed the iron(II) chloride, previously solubilizated in tetrahydrofuran (THF). The organic ligand characterization was accomplished trough nuclear magnetic resonance (NMR) and Infrared spectroscopy (IV). The supports were characterized with x-ray diffraction (DRX), texture analysis with nitrogen adsorption/desorption (before and after the anchoring), termogravimetric analysis (TG) and infrared (IV). The metalic content was quantified trough the atomic absorption spectrophotometry (AAS). The complexes were tested in catalytic reactions emolying ethylaluminium sesquichloride (EASC) as co-catalyst in steel reactor, under mecanic stirring. The reaction conditions ranged from 4 to 36 ◦C, with many aluminum/iron ratios. The catalysts were actives in homogeneous and heterogenized ways. The homogenous catalytic complex showed a maximum turnover frequency (TOF) of 8.63 ×103 · h −1 , while, in some conditions, the anchored complexes showed better results, with TOF of until 8.08 ×103 · h −1 . Aditionally, it was possible to determine an equation, to the homogenous catalyst, that describes the product quantity in function of reacional temperature and aluminum/iron ratio.

Autonomic hardware manager: uma arquitetura de hardware autonômico usando a solução de repositório ativo de componentes

This Thesis main objective is to implement a supporting architecture to Autonomic Hardware systems, capable of manage the hardware running in reconfigurable devices. The proposed architecture implements manipulation, generation and communication functionalities, using the Context Oriented Active Repository approach. The solution consists in a Hardware-Software based architecture called "Autonomic Hardware Manager (AHM)" that contains an Active Repository of Hardware Components. Using the repository the architecture will be able to manage the connected systems at run time allowing the implementation of autonomic features such as self-management, self-optimization, self-description and self-configuration. The proposed architecture also contains a meta-model that allows the representation of the Operating Context for hardware systems. This meta-model will be used as basis to the context sensing modules, that are needed in the Active Repository architecture. In order to demonstrate the proposed architecture functionalities, experiments were proposed and implemented in order to proof the Thesis hypothesis and achieved objectives. Three experiments were planned and implemented: the Hardware Reconfigurable Filter, that consists of an application that implements Digital Filters using reconfigurable hardware; the Autonomic Image Segmentation Filter, that shows the project and implementation of an image processing autonomic application; finally, the Autonomic Autopilot application that consist of an auto pilot to unmanned aerial vehicles. In this work, the applications architectures were organized in modules, according their functionalities. Some modules were implemented using HDL and synthesized in hardware. Other modules were implemented kept in software. After that, applications were integrated to the AHM to allow their adaptation to different Operating Context, making them autonomic.

Características bioativas, funcionais e efeito protetor do resíduo desidratado de camu-camu (Myrciaria dubia H.B.K. (McVaugh)) sobre doenças degenerativas utilizando modelos in vivo C. elegans

Camu-camu (Myrciaria dubia H.B.K. (McVaugh)) is a native Amazon fruit, recognized worldwide as one of the main natural sources of ascorbic acid. Due to its great acidity, this fruit is generally consumed after processing into juice or as ingredient in food preparations. As a co-product of the camu-camu processing, a significant amount of agroindustrial residue is generated. Despite the studies showing the bioactive value and biological potential of the fruit, few studies have approached the possible processing techniques, transformation and preservation of camu-camu fruits and its agroindustrial pomace. Therefore, the present work has the objective of evaluating two different drying processes applied to camu-camu pomace (peel and seeds with residual pulp), freeze drying and hot air drying, in order to obtain a functional fruit product. This thesis was divided into three stages: the first one shows the studies related to the freeze drying and hot air drying, where we demonstrated the impact of the selected drying techniques on the bioactive components of camu-camu, taking the fresh pomace as the control group. Among the investigated conditions, the groups obtained at 50ºC and 4 m/s (SC50) and 80ºC and 6 m/s (SC80) were selected as for further studies, based on their ascorbic acid final content and Folin-Ciocalteau reducing capacity. In addition to SC50 and SC80, the fresh pomace (RF) and freeze dried (RL) samples were also evaluated in these further stages of the research. Overall, the results show higher bioactive concentration in the RF samples, followed by RL, SC50 and SC80. On the second step of the research, the antioxidant, antimicrobial and antienzymatic activities were evaluated and the same tendency was observed. It was also reported, for the first time in the literature, the presence of syringic acid in dried camu-camu pomace. In the third and final stage of the research, it was investigated the effect of dried camu-camu on aging and neuroprotective disorders, using the in vivo model C.elegans. It was observed that camu-camu extracts were able to modulate important signaling genes relevant to thermal and oxidative stresses (p < 0.05). The polar acid, polar basic and polar neutral fractions obtained from the low molecular extracts of SC50 were able to extend the lifespan of wild type N2 C. elegans in 20% and 13% (p < 0.001). Results also showed that the paralysis induced by the β1-42 amyloid was significantly (p < 0.0001) retarded in CL4176 worms. Similarly, the camu-camu extracts attenuated the dopaminergic induction associated to Parkinson’s disease. Finally, a global analysis of the data presented here reveal that the camu-camu pomace, a co-product obtained from the industrial processing of a native Brazilian fruit, is a relevant natural source of health relevant compounds. This thesis, shows for the first time, the multifunctionality of camu-camu pomace, a natural resource still underexploited for scientific, commercial and technological purposes.

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

Modificação do eletrodo AWS E7018 com adição de filmes finos externos de PVC e Al, para soldagem de aço C-Mn

This paper suggests modifications in coating of electrodes providing an alternative for execution of welding with low hydrogen electrode AWS E7018 without having to dry it, reducing thus the cost and time of manufacturing of high resistance welds. The welds in this research were developed with basic coated electrodes (hygroscopic) – SMAW process – externally painted with aluminum spray paint for high temperatures or wrapped with thin plastic films (PVC) and aluminum foil films used commonly for food protection. The basic premise is that establishing a barrier between the atmosphere and the electrode coating could reduce the effects of high hygroscopicity presented by coatings of low hydrogen, minimizing this way the main source of supply of hydrogen to the fusion pool during welding. It is also expected that the addition of new materials from the electrode coating to the fusion pool would induce metallurgical changes in the deposited metal and, as a consequence, modifications in its mechanical properties. This research dealt with measuring the dissolved hydrogen in the deposited metal after welding with modified electrodes, evaluating the influence of these changes in the produced microstructures and in the mechanical properties of the resulting weld, and comparing the obtained results with the standard welding procedures and with the recently developed waterproof electrodes. The results obtained in most samples welded with modified electrodes showed increased mechanical resistance and increased tenacity due to the increased percentage of acicular ferrite in metal deposited without significant elevation of hardness, when compared with the traditional welding with AWS E7018 electrode and with ELBRÁS BRH4R waterproof electrode. The diffusing hydrogen measured in the modified electrodes was kept inside the parameters defined by international codes.

No fio da meada: um estudo acerca da precarização do trabalho na indústria têxtil

In line with the process of financialization and globalization of capital, which has intensified in all latitudes of the globe, the world of work is permeated by his determinations arising and also has been (re) setting from numerous changes expressed by example, in the unbridled expansion of temporary forms of work activities, and flexible outsourced by the growth of informality, forming a new morphology of work. However, regardless of how these forms are expressed in concrete materiality, there is something that unifies: all of them are marked by exponentiation of insecurity and hence the numerous negative effects on the lives of individuals who need to sell their labor power to survive. Given this premise, the present work is devoted to study, within the framework of the Brazilian particularities of transition between Fordism and Toyotism, what we call composite settings of the conditions and labor relations processed within the North river- textile industry Grande. To this end, guided by historical and dialectical materialism, we made use of social research in its qualitative aspect, using semi-structured interviews, in addition to literature review, information retrieval and use of field notes. From our raids, we note that between the time span stretching from the 1990s to the current year, the Natal textile industry has been undergoing a process of successive and intense changes in their modus operandi, geared specifically to the organization and labor management causing, concomitantly, several repercussions for the entire working class.

No fio da meada: um estudo acerca da precarização do trabalho na indústria têxtil

In line with the process of financialization and globalization of capital, which has intensified in all latitudes of the globe, the world of work is permeated by his determinations arising and also has been (re) setting from numerous changes expressed by example, in the unbridled expansion of temporary forms of work activities, and flexible outsourced by the growth of informality, forming a new morphology of work. However, regardless of how these forms are expressed in concrete materiality, there is something that unifies: all of them are marked by exponentiation of insecurity and hence the numerous negative effects on the lives of individuals who need to sell their labor power to survive. Given this premise, the present work is devoted to study, within the framework of the Brazilian particularities of transition between Fordism and Toyotism, what we call composite settings of the conditions and labor relations processed within the North river- textile industry Grande. To this end, guided by historical and dialectical materialism, we made use of social research in its qualitative aspect, using semi-structured interviews, in addition to literature review, information retrieval and use of field notes. From our raids, we note that between the time span stretching from the 1990s to the current year, the Natal textile industry has been undergoing a process of successive and intense changes in their modus operandi, geared specifically to the organization and labor management causing, concomitantly, several repercussions for the entire working class.

Assistência social ao idoso no município de Natal na proteção social básica: identificando demandas e desafios

Over the past decades, starting mainly in the 1960s, the number of elderly has grown in the country and an aging population is considered a remarkable global phenomenon. Given the speed of this process, this growth has produced different implications for the structure of the social, economic and cultural societies and, as such, constitutes new challenges for public policy, and particularly for the Brazilian social assistance policy. Considering the significant increase aging population in Natal and the challenges of social welfare policy, this research aims to identify and analyze the demands and challenges of Social Assistance Policy in the city of Natal / RN, in particular the access of the elderly to social protection basic in the Reference Centers of Social Assistance. This research uses a critical dialectical method, and the methodological procedures that guided the study: the bibliographical research, documentary and field as well as systematic observation. Some initial questions were important to guide this work: What are the demands that come to CRAS the elderly population? What are the answers to these demands by the Basic Social Protection? How this CRAS has implemented social protection responses to these demands as rights guarantee the elderly population? The services offered by CRAS meets user needs? To get the results of this research, bibliographic sources were used, documentary and observation for four (4) CRAS of different district areas of the city of Natal. The results of this research show that basic social protection is quite fragile, leaving part of the population at risk and social vulnerability still without attention due to several factors, including the reduced technical team and the impossibility of service to all neighborhoods referenced by CRAS in the respective zones, and 50% of elderly assisted arising from spontaneous demands.

Assistência social ao idoso no município de Natal na proteção social básica: identificando demandas e desafios

Over the past decades, starting mainly in the 1960s, the number of elderly has grown in the country and an aging population is considered a remarkable global phenomenon. Given the speed of this process, this growth has produced different implications for the structure of the social, economic and cultural societies and, as such, constitutes new challenges for public policy, and particularly for the Brazilian social assistance policy. Considering the significant increase aging population in Natal and the challenges of social welfare policy, this research aims to identify and analyze the demands and challenges of Social Assistance Policy in the city of Natal / RN, in particular the access of the elderly to social protection basic in the Reference Centers of Social Assistance. This research uses a critical dialectical method, and the methodological procedures that guided the study: the bibliographical research, documentary and field as well as systematic observation. Some initial questions were important to guide this work: What are the demands that come to CRAS the elderly population? What are the answers to these demands by the Basic Social Protection? How this CRAS has implemented social protection responses to these demands as rights guarantee the elderly population? The services offered by CRAS meets user needs? To get the results of this research, bibliographic sources were used, documentary and observation for four (4) CRAS of different district areas of the city of Natal. The results of this research show that basic social protection is quite fragile, leaving part of the population at risk and social vulnerability still without attention due to several factors, including the reduced technical team and the impossibility of service to all neighborhoods referenced by CRAS in the respective zones, and 50% of elderly assisted arising from spontaneous demands.

Implementação de uma matriz de neurônios dinamicamente reconfigurável para descrição de topologias de redes neurais artificiais multilayer perceptrons

The Artificial Neural Networks (ANN), which is one of the branches of Artificial Intelligence (AI), are being employed as a solution to many complex problems existing in several areas. To solve these problems, it is essential that its implementation is done in hardware. Among the strategies to be adopted and met during the design phase and implementation of RNAs in hardware, connections between neurons are the ones that need more attention. Recently, are RNAs implemented both in application specific integrated circuits's (Application Specific Integrated Circuits - ASIC) and in integrated circuits configured by the user, like the Field Programmable Gate Array (FPGA), which have the ability to be partially rewritten, at runtime, forming thus a system Partially Reconfigurable (SPR), the use of which provides several advantages, such as flexibility in implementation and cost reduction. It has been noted a considerable increase in the use of FPGAs for implementing ANNs. Given the above, it is proposed to implement an array of reconfigurable neurons for topologies Description of artificial neural network multilayer perceptrons (MLPs) in FPGA, in order to encourage feedback and reuse of neural processors (perceptrons) used in the same area of the circuit. It is further proposed, a communication network capable of performing the reuse of artificial neurons. The architecture of the proposed system will configure various topologies MLPs networks through partial reconfiguration of the FPGA. To allow this flexibility RNAs settings, a set of digital components (datapath), and a controller were developed to execute instructions that define each topology for MLP neural network.

Implementação de uma matriz de neurônios dinamicamente reconfigurável para descrição de topologias de redes neurais artificiais multilayer perceptrons

The Artificial Neural Networks (ANN), which is one of the branches of Artificial Intelligence (AI), are being employed as a solution to many complex problems existing in several areas. To solve these problems, it is essential that its implementation is done in hardware. Among the strategies to be adopted and met during the design phase and implementation of RNAs in hardware, connections between neurons are the ones that need more attention. Recently, are RNAs implemented both in application specific integrated circuits's (Application Specific Integrated Circuits - ASIC) and in integrated circuits configured by the user, like the Field Programmable Gate Array (FPGA), which have the ability to be partially rewritten, at runtime, forming thus a system Partially Reconfigurable (SPR), the use of which provides several advantages, such as flexibility in implementation and cost reduction. It has been noted a considerable increase in the use of FPGAs for implementing ANNs. Given the above, it is proposed to implement an array of reconfigurable neurons for topologies Description of artificial neural network multilayer perceptrons (MLPs) in FPGA, in order to encourage feedback and reuse of neural processors (perceptrons) used in the same area of the circuit. It is further proposed, a communication network capable of performing the reuse of artificial neurons. The architecture of the proposed system will configure various topologies MLPs networks through partial reconfiguration of the FPGA. To allow this flexibility RNAs settings, a set of digital components (datapath), and a controller were developed to execute instructions that define each topology for MLP neural network.

Estudo da evolução das tensões residuais através da difratometria de raios x em aço rolamento submetido a esforços cíclicos

The micro-deformations caused by cyclic loading origins the variation of the distances between atoms of the crystal lattice producing the irreversible component. In order to study and understand the microstructural behavior of the material this paper investigated the influence suffered by residual stresses in thrust rolling bearing races fabricated in AISI 52100 steel, after tests by cyclic rolling contact in a tribometer at 1m/s under two contact pressures (500 MPa and 1400 MPa) in dry and boundary lubrication conditions. Procedures of tests thermo-acustically isolated were developed for monitoring the contact temperature and sound pressure level signals to establish a comparison between the residual stress measurements, micro-hardness Vickers and micrographic registers searching an indication of wear evolution. The sin²ψ method by X-ray diffraction technique was used to quantify the residual stresses. Three raceway zones were selected for the evaluation of wear and surface morphology after predetermined cycling, comparing with their new condition ("as received"). Micro-hardness and residual stress measurements showed significant changes after the tests and it was possible to observe the relationship between the increase of sound pressure level and the residual stress for dry and lubricated conditions.