Metodologia para implantação de um sistema de disposição de rejeitos em minério de ferro na região do semiárido: estudo de caso

Tailings dams are structures that aims to retain the solid waste and water from mining processes. Its analysis and planning begins with searching of location for deployment, step on which to bind all kinds of variables that directly or indirectly influence the work, such as geological, hydrological, tectonic, topographic, geotechnical, environmental, social characteristics, evaluation security risks, among others. Thus, this paper aims to present a study on the most appropriate and secure type of busbar to design a layout structure of iron ore tailings, taking into account all the above mentioned variables. The case study involves the assessment of sites for location of dams of tailings disposal beneficiation of iron mine to be built in Bonito, in the municipality of Jucurutu in Seridó Potiguar. For site selection among alternatives, various aspects of the current state of the art were considered, one that causes the least environmental impact, low cost investment, adding value to the product and especially the safety of the implanted structure mitigates the concern about induced earthquakes as a result of liquefaction wastes somatized by dams in the region, as the tilling of Mina Bonito is located practically in the hydraulic basin dam Armando Ribeiro in environmental protection (APA). The methodology compares induced by dams in the semiarid region with the characteristics of the waste disposal and sterile seismicity, taking into account the enhancement of liquefaction by the action of seismicity in the Mina Bonito region. With the fulcrum in the methodology, we indicated the best busbar type for disposal of tailings from iron ore or combination of them, to be designed and built in semiarid particularly for Mina Bonito. Also presents a number of possible uses for the tailings and in engineering activities, which may cause processing to the common good.

Síntese e caracterização de catalisadores baseados em vermiculita modificada com ferro: aplicação em processos do tipo foto-fenton

Clays are materials with specific properties that make them promising for various studies. In this work we used the vermiculite clay as support for iron compounds, in order to obtain promising materials for application in the heterogeneous type photo-Fenton process. In all, the study included six solid, starting from the vermiculite (V0) was obtained calcined vermiculite (V0-C), the mixed material (V0/β-FeOOH) formed by vermiculite more akaganeite, exchanged vermiculite (v0t-C), vermiculite impregnated Wet (V0u-C) and V0u-CL that is the solid obtained by impregnating with a back washing. The solids of the study had their physical and chemical characteristics investigated by the following characterization techniques: X-Ray Diffraction (XRD), Infrared Spectroscopy (IR), Energy Dispersive Spectroscopy (EDS), X-Ray Fluorescence Spectroscopy (XRF), UV-Vis by Diffuse Reflectance (DR UV-Vis), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). The V0 material showed three distinct phases, which are the very vermiculite, hidrobiotite and biotite, the last two phases are part of the geological of formation process vermiculite. The solids obtained after the modification showed an increase in the amount of iron present in the clay, these being quantities important for application in photocatalysis. The micrographs and EDS data, show that after treatment of addition of the metal , the iron was intercalary in structure of vermiculite for solid V0t-C and V0u-C, however, this did not occur with mixed material. In the photoFenton process, was observed a maximum removal of 88.8% of the dye methylene blue coloring for the catalyst V0/β-FeOOH, while for the other solids was obtained values between 76.8 and 62.6%, compared to 37.8% of discoloration without the presence of catalyst. Therefore, it is concluded that the vermiculite clay presents as a good catalyst and iron support for the, beyond of presenting a low cost because of its high abundance.

Gestão do sistema de produção e práticas enxutas adotadas nas indústrias paraibanas: um estudo multicaso

The evolution of the practices and strategies of manufacturing management, over the years, has made many companies realign their production systems in order to raise their competitiveness and operational performance. However, in most cases these changes are made in a heterogeneous manner, which ends up leaving the production system without a defined goal, which may end up damaging the managerial strategies of the organization as a whole. Thus, some organizations seek to use techniques and/or successful production practices used by other companies, believing can be able to reproduce the same results. An efficient production system must be fully planned and appropriate to the strategic objectives of the organization. Thus, this paper aims to identify the manufacturing management strategies adopted in paraibanas industries, as well as identify the lean practices used by them. Thus, a qualitative study was conducted, using as methodological basis the multicase study. Were made: direct observations, semi-structured interviews and questionnaires applied to those responsible by the production sector of the participating companies. As a result, it was possible to identify the type of manufacturing management system adopted by companies. Where it was detected that Company A uses a system of Modern Mass Production with focus on productivity and low cost and the Company B is using Lean Manufacturing system focused on quality and diversity. In the two organizations was possible to realize the application of lean practices where the Company what does not use the LM, possessed lean practices in standard extremely mature of utilization.

Avaliação de sistemas de lagoas de estabilização em série no Rio Grande do Norte

Stabilization ponds are biological treatment systems in that stabilization of organic matter is performed by the bacterial oxidation and / or reduction of photosynthetic algae. This study aimed to monitor and evaluate the efficiency of stabilization ponds in the Rio Grande do Norte State. Collections were made of the treated effluent, made directly in the output boxes of facultative lagoons and maturation (M1 and M2) and raw sewage (EB) that arrived at the stations. The variables analyzed were: pH, temperature, dissolved oxygen, total suspended solids, chlorophyll "a", apparent color, total phosphorus, organic nitrogen, ammonia nitrogen, Kjeldahl nitrogen, turbidity, cyanobacteria density and concentrations of microcystin. Variance analysis (ANOVA one way) observing the premises using the Tukey test, so as to check differences between treatments. The evaluate the stations found to COD removals in the bands of 48,8% (Pipa) to 75,8% (Caiçara Rio do Vento) and 57,5% (Pipa) to 83,0% (Santo Antônio), respectively. The mean concentrations of cyanobacteria varied from LFs density of 62,545 cels.mL-1 (Pedro Velho Roça) cels.mL-1 to 2,669,048 (Ponta Negra), while the final effluent showed range between 9,072 Cels.mL- 1 (Pedro Velho Roça) to 1,899,981 cels.mL-1 (Macau – Ilha de Santana) and the average concentrations of microcystin the final effluent ranged from 0.02 μg.L-1 (Ponta Negra) to 0.15 μg.L-1 (Macau – Ilha de Santana) at the studied the stations.

Prevalência e fatores associados à alteração vocal em idosos institucionalizados com capacidade cognitiva preservada

Voice disorders (VD) in the elderly can interfere negatively in communication, emotional well-being and quality of life, conditions that correspond to greater exposure to illness and social isolation bringing consequent economic impact for the health system. It is assumed that institutionalized confinement, weakness and morbidity associated to nursing home (NH) contribute to transform VD an especially prevalent condition in institutionalized elderly, including those without cognitive impairment. Thus, the aim of this study was to determine the prevalence and associated factors of VD in NH elderly residents without cognitive impairment. There is no epidemiological diagnostic instruments of VD for elderly populations, so the first step of this study was dedicated to prepare and analyze the psychometric properties of a short, inexpensive and easy to use questionnaire named Screening for Voice Disorders in Older Adults (Rastreamento de Alterações Vocais em Idosos—RAVI). The methodological procedures of this step followed the guidelines of the Standards for Educational and Psychological Testing and contemplated validity evidence based on test content, based on response processes, based on internal structure and based on relations with other variables, as well as reliability analysis and clinical consistency. The result of the validation process showed that the RAVI final score generate valid and reliable interpretations for the epidemiological diagnosis of VD in the elderly, which endorsed the use of the questionnaire in the second stage of the study, performed in ten NH located in the city of Natal, Rio Grande do Norte. At this stage, data from socioeconomic and demographic variables, lifestyle, general health conditions and characterization of the institution were collected. It was performed a bivariate analysis and it was calculated the prevalence ratio as a magnitude association measure, with a confidence interval of 95%. The variables with p-value less than 0.20 were included in the multiple logistic regression model that followed the Forward selection method. The odds ratio found in the multivariate model was converted into prevalence ratio and the level of significance was 5%. The sample consisted of 117 subjects with predominance of females and average of 79.68 (± 7.92) years old. The prevalence of VD was 39.3% (95% CI: 30.4-48.1%). The multivariate model showed statistically significant association between VD and depressive symptoms, smoking for a year or more and selfreported hearing loss. In conclusion, VD is a prevalent health condition in NH elderly residents without cognitive impairment and is associated with factors involving psychosocial, lifestyle and communicative disability that require attention of managers and professionals involved with NH environment. Strategies to encourage communication and social integration, actions to combat smoking and minimizing the effects of hearing loss could stimulate the physical well-being, emotional and mental health of institutionalized elderly population, contributing to the vocal and communicative maintenance, a more effective social inclusion and better overall health condition.

Desenvolvimento e avaliação do emprego de dispositivo ajustável ao corpo para treinamento de habilidade de acesso venoso periférico no membro superior

OBJECTIVE: To dev elop and evaluate the use of a body adjustable device for training of peripheral venous catheterization for healthcare undergraduate students . METHODS: This study involved two phases: I) development of the innovative simulator and II) a controlled trial co mparing the performance of the body adjustable device in relation to the commercial simulator for the training of venipuncture skills. A total of 79 first - year medical students participated in the intervention phase, which consisted of pretest assessment, lecture on peripheral venous access, randomization into two groups according to the simulator used for training (Commercial Simulator and Experimental Simulator), real venipuncture procedure, post - test assessment and evaluation of satisfaction. RESULTS: Gr oups were homogeneous in age, sex, pre - test and post - test scores, attitudinal assessment and performance in performing the real venipuncture. Students from the Experimental Simulator group performed better on the filling of simulated records. At the end of the study, cognitive gain significantly increased in both groups. The degree of realism perceived by students was equivalent for two groups. A total of 85.7% of students rated the Experimental Simulator as good or excellent. CONCLUSIONS: Experimental simu lator proved to be a low cost alternative for the training of venipuncture skills in upper limb. The cognitive procedural and attitudinal performances of students who used the experimental simulator were similar to those observed in the group trained with commercial simulator.

Síntese e reatividade de derivados de quinoxalina visando aplicações como quimiossensores e estudo cinético por análise de imagens

Synthesis of heterocyclic compounds, as quinoxaline derivatives, has being shown to be relevant and promissor due to expressive applications in biological and technological areas. This work was dedicated to the synthesis, characterization and reactivity of quinoxaline derivatives in order to obtain new chemosensors. (L)-Ascorbic acid (1) and 2,3-dichloro-6,7- dinitroquinoxalina (2) were explored as synthetic precursors. Starting from synthesis of 1 and characterization of compounds derived from (L)-ascorbic acid, studies were performed investigating the application of products as chemosensors, in which compound 36 demonstrated selective affinity for Cu2+ íons in methanolic solution, by naked-eye (colorimetric) and UVvisible analyses. Further, initial analysis suggests that 39 a Schiff’s base derived from 36 also presents this feature. Five quinoxaline derivatives were synthesized from building block 2 through nucleophilic aromatic substitution by aliphatic amines, in which controlling the experimental conditions allows to obtain both mono- and di-substituted derivatives. Reactivity studies were carried out with two purposes: i) investigate the possibility of 47 compound being a chemosensor for anion, based on its interaction with sodium hydroxide in DMSO, using image analysis and UV-visible spectroscopy; ii) characterize kinetically the conversion of compound 44 into 46 based on RGB and multivariate image analysis from TLC data, as a simple and inexpensive qualitative and quantitative tool.

Aplicação de nanoemulsão ácida em acidificação de poços de petróleo

A constante busca da indústria de petróleo pelo aumento de produção à um baixo custo operacional faz necessário o desenvolvimento de tecnologias que una as duas necessidades. A Acidificação de matriz é um método de estimulação frequentemente empregado para aumentar produção de um poço de petróleo com um custo menor se comparado a um fraturamento. O objetivo deste trabalho é estudar a obtenção de nanoemulsões ácidas para aplicação em acidificação de matriz. As nanoemulsões são capazes de retardar reações, por diminuir a difusão do ácido no meio, possibilitando a acidificação em reservatórios com baixa permeabilidade. Os reagentes utilizados para formar os sistemas nanoemulsionados foram UNT L90/OMS e RNX 110 como tensoativos, Sec-butanol como cotensoativo, Xileno e Querosene como fase óleo e Solução de HCl como fase aquosa. As nanoemulsões foram obtidas a partir da diluição de microemulsões com água ou solução de HCl. Foi realizado estudo das tensões superficiais, estudo das cinéticas de reação, avaliação da injeção em rocha carbonática e remoção de borra asfáltica. As nanoemulsões apresentaram tensão superficial menor que suas microemulsões de origem. As nanoemulsões tiveram êxito em retardar a reação entre CaCO3 e HCl, onde o sistema mais eficiente é composto por UNT L90/OMS, Secbutanol, Querosene e solução de HCl. As nanoemulsões foram eficientes em formar wormholes em plugs de carbonato calcitico com baixa permeabilidade natural. As wormholes proporcionaram incremento de permeabilidade alcançando valores de até 390 mD. O sistema ácido apresentou bom resultado de remoção de borra asfáltica, mostrando o potencial das nanoemulsões em remover esse tipo de dano. Conclui-se que os sistemas nanoemulsionados têm grande potencial de aplicação em acidificação de matriz.

Tratamento superficial de argilas com cera de carnaúba e microemulsão de óleo de coco

Adsorption is a process that has become indispensable due to pollution caused by industrial activity. More economically viable adsorbents are being tested to replace the high cost of materials used. The clays can be used as adsorbents and are low cost materials, natural properties feasible for the application in the adsorption process, structural modifications are performed with ease promoting selective adsorption in these materials. The objective of this study was to synthesize and characterize adsorbents used in the adsorption of organic compounds. The adsorbents were characterized by the techniques of XRD, SEM, FTIR and TG. The results show that the studied materials have affinity to organic compounds and can be applied as adsorbents. The materials studied are viable and can be applied in the treatment of effluents contaminated in industrial scale.

FTE-LEACH: um protocolo energeticamente eficiente e tolerante a falhas aplicado às redes industriais de sensores sem fio

A Wireless Sensor Network (WSN) consists of distributed devices in an area in order to monitor physical variables such as temperature, pressure, vibration, motion and environmental conditions in places where wired networks would be difficult or impractical to implement, for example, industrial applications of difficult access, monitoring and control of oil wells on-shore or off-shore, monitoring of large areas of agricultural and animal farming, among others. To be viable, a WSN should have important requirements such as low cost, low latency, and especially low power consumption. However, to ensure these requirements, these networks suffer from limited resources, and eventually being used in hostile environments, leading to high failure rates, such as segmented routing, mes sage loss, reducing efficiency, and compromising the entire network, inclusive. This work aims to present the FTE-LEACH, a fault tolerant and energy efficient routing protocol that maintains efficiency in communication and dissemination of data.This protocol was developed based on the IEEE 802.15.4 standard and suitable for industrial networks with limited energy resources

Influência do retardante de chamas nas propriedades mecânicas e flamabilidade em compósitos poliméricos de epóxi/fibra de curauá

Currently, there is a great search for materials derived from renewable sources. The vegetable fibers as reinforcement for polymer matrixes, has been used as an alternative to replace synthetic fibres, being biodegradable and of low cost. The present work aims to develop a composite material with epoxy resin reinforced with curauá fibre with the addition of alumina trihydrate (aluminum hydroxide, Al(OH)3) as a flame retardant, which was used in proportions of 10 %, 20% and 30% of the total volume of the composite. The curauá fibers have gone through a cleaning process with an alkaline bath of sodium hydroxide (NaOH ), parallelized by hand and cut carding according to the default length . They were molded composites with fibers 30cm. Composites were molded in a Lossy Mold with unidirectional fibres in the proportion of 20% of the total volume of the composite. The composites were prepared in the Chemical Processing Laboratory of the Textile Engineering Department at UFRN. To measure the performance of the material, tests for the resistance to traction and flexion were carried out. with samples that were later analyzed in the Electronic Microscopy Apparatus (SEM ). The composites showed good mechanical properties by the addition of flame retardant and in some cases, leaving the composite more vulnerable to breakage. These mechanical results were analyzed by chi-square statistical test at the 5% significance level to check for possible differences between the composite groups. Flammability testing was conducted based on the standard Underwriters Laboratory 94 and the material showed a satisfactory result taking their average burn rate (mm / min) decreasing with increasing addition of the flame retardant composite.

Produção de filtrantes ativados a partir de aproveitamento de resíduos: uma proposta para a proteção respiratória ocupacional

A Proteção Respiratória Ocupacional é atualmente uma exigência legal do Ministério do Trabalho e Emprego para garantia da saúde e segurança de milhares de trabalhadores que labutam com exposição habitual a substâncias nocivas que possam ocasionar doenças ocupacionais por inalação de ar contaminado no local de trabalho, cuja principal via de penetração no organismo humano é o Sistema Respiratório. Carvões ativados são materiais obtidos a partir de fontes carbonáceas e utilizados como elemento tecnológico filtrante nos equipamentos destinados a proteção respiratória individual. Fomentada por esse contexto, e visando potencializar conceitos de eco-eficiência e sustentabilidade em produção de materiais, este trabalho destina-se a produção de carvão ativado com potencial filtrante a partir de um rejeito agrícola abundante na região Nordeste do Brasil através de uma rota que favorece carbonização e ativação simultâneas, seguido de neutralização térmica. A biomassa precursora foi caracterizada por Ensaios padrões para determinação do teor de umidade e cinzas, Análise Química Elementar, Análises Térmicas (TG e DSC) e Distribuição Granulométrica por difração a laser. As amostras de carvões ativos sintetizadas foram caracterizadas por Difração de Raios X (DRX), Medidas de área específica por BET, Microscopia Eletrônica de Varredura (MEV), Análise assistida com ultravioleta visível e Redução à Temperatura Programada (TPR) por Amônia. A rota empregada favorece uma tecnologia alternativa para o aproveitamento de resíduos e aplicável para a Proteção Respiratória Ocupacional. A atmosfera de queima influencia diretamente na produção. A temperatura de carbonização variou conforme a estabilidade térmica da amostra. A cristalinidade, morfologia, teor mineralógico, área superficial específica e a adsorção em fase líquida e gasosa variaram em função da interação do resíduo precursor com o tipo e concentração de ácido utilizado. Os ensaios de adsorção demonstraram a efetividade da ativação segundo a rota experimental proposta. O potencial catalítico dos materiais produzidos para uso em máscaras respiratórias foi evidenciado pelo ensaio de TPR. O processo de produção estudado se mostrou eficaz para obtenção dos carvões promovendo processamentos e aplicações mais nobres para materiais cujo uso tem sido restrito a meras aplicações primárias ou descarte, mas cujo potencial tecnológico é amplo, empreendedor, sustentável, viável em escala industrial e de baixo custo.

Aplicação e otimização de métodos eletroquímicos combinados para remoção e determinação de cromo hexavalente em efluentes simulados

Hexavalent chromium is a heavy metal present in various industrial effluents, and depending on its concentration may cause irreparable damage to the environment and to humans. Facing this surrounding context, this study aimed on the application of electrochemical methods to determine and remove the hexavalent chromium (Cr6+) in simulated wastewater. To determine was applied to cathodic stripping voltammetry (CSV) using ultra trace graphite electrodes ultra trace (work), Ag/AgCl (reference) and platinum (counter electrode), the samples were complexed with 1,5- diphenylcarbazide and then subjected to analysis. The removal of Cr6+ was applied electrocoagulation process (EC) using Fe and Al electrodes. The variables that constituted the factorial design 24, applied to optimizing the EC process, were: current density (5 and 10 mA.cm-2), temperature (25 and 60 ºC), concentration (50 and 100 ppm) and agitation rate (400 and 600 RPM). Through the preliminary test it was possible the adequacy of applying the CSV for determining of Cr6+, removed during the EC process. The Fe and Al electrodes as anodes sacrifice showed satisfactory results in the EC process, however Fe favored complete removal in 30 min, whereas with Al occurred at 240 min. In the application of factorial design 24 and analysis of Response Surface Methodology was possible to optimize the EC process for removal of Cr6+ in H2SO4 solution (0.5 mol.L-1), in which the temperature, with positive effect, was the variable that presented higher statistical significance compared with other variables and interactions, while in optimizing the EC process for removal of Cr6+ in NaCl solution (0.1 mol.L-1) the current density, with positive effect, and concentration, with a negative effect were the variables that had greater statistical significance with greater statistical significance compared with other variables and interactions. The utilization of electrolytes supports NaCl and Na2SO4 showed no significant differences, however NaCl resulted in rapid improvement in Cr6+ removal kinetics and increasing the NaCl concentration provided an increase in conductivity of the solution, resulting in lower energy consumption. The wear of the electrodes evaluated in all the process of EC showed that the Al in H2SO4 solution (0.5 mol.L-1), undergoes during the process of anodization CE, then the experimental mass loss is less than the theoretical mass loss, however, the Fe in the same medium showed a loss of mass greater experimental estimated theoretically. This fact is due to a spontaneous reaction of Fe with H2SO4, and when the reaction medium was the NaCl and Na2SO4 loss experimental mass approached the theoretical mass loss. Furthermore, it was observed the energy consumption of all processes involved in this study had a low operating cost, thus enabling the application of the EC process for treating industrial effluents. The results were satisfactory, it was achieved complete removal of Cr6+ in all processes used in this study.

Materiais bionanocompósitos a base de argilominerais e hidróxidos duplos lamelares como sistemas de liberação de fármacos

Bionanocomposites systems clay base (montmorillonite and sepiolite), layered double hidroxides and biopolymers (carboxymethylcellulose and zein) were evaluated as topical delivery systems with antibacterial activity and as oral delivery systems. For this study, neomycin, a topical antibiotic, indicated mainly for open wound infections. The drug amoxicillin, an antibiotic indicated mainly for throat infections, were also used in this study. Both antibiotics were used as model drugs. Initially, drugs were incorporated directly into the biopolymer matrix, comprising the combination of carboxymethylcellulos and zein, being conformed as movies and balls and evaluated for their antibacterial activity and controlled release simulating gastrointestinal fluids. Moreover, hybrids materials have been prepared where the neomycin drug was incorporated into the lamellar inorganic solids, such as montmorillonite by ion exchange reaction, and the fibrous type, such as sepiolite by adsorption in aqueous solution. But the drug amoxicillin was incorporated into layered double hydroxides by anion exchange and montmorillonite by cation exchange. The resulting hybrids were in turn combined with the biopolymer matrix yielding bionanocomposites shaped materials such as films were tested for their antibacterial activity, and the shaped materials beads were tested for their release in the gastrointestinal fluids. Through the analysis of various physico-chemical techniques, we observed the interactions between the studied materials, the formation of hybrids materials, obtaining the bionanocomposites materials and material efficiency when applied in controlled release of drugs both topical and use oral mainly influenced by the presence of zein, are promising as topical delivery systems and oral drugs.

Duplicação rápida de prótese total: passo-a-passo

This study presents a simple, fast and low cost technique for fabrication new conventional dentures from the duplication of old prosthesis in use by the patient. Colorless acrylic resin was poured into the moulds obtained by duplication of prosthesis. With the replicas obtained a functional impressions using polyether should be performed and they are stabilized with occlusal registration in acrylic resin. The molds need to be castings and mounted on an semi-adjustable articulator. The artificial teeth are positioned with the assistance of a guide made condensation silicone to reproduce the positioning of the teeth of the old prosthesis and fixed with wax 7. After approval of the teeth on the trial in wax, without adjustment of the planes, the prosthesis may be processed in the laboratory. After occlusal adjustment in the articulator the same can be installed.