EAJ - Artigos publicados em periódicos

URI Permanente para esta coleçãohttps://repositorio.ufrn.br/handle/1/2966

Navegar

Agora exibindo 1 - 20 de 34

Antecedentes del comportamiento pro ambiental de los residentes de una comunidad turística costera en el nordeste de Brasil
(Estudios y Perspectivas en Turismo, 2020) Silva, Clébia Bezerra da; Nascimento, Edson Domingos; Marques Júnior, Sérgio
El turismo de sol y playa es uno de los más tradicionales en el mundo entero. De esta forma, las zonas costeras sufren una gran presión de las actividades antrópicas, como la causada por el turismo. Así, el objetivo es investigar los factores capaces de influir el comportamiento ambiental de los residentes en comunidades turísticas costeras en desarrollo. El recorte geográfico de esta investigación es la comunidad de Barra do Cunhaú, municipio de Canguaretama en el litoral sur de Rio Grande do Norte, localizada aproximadamente a 79 Km de Natal, mayor destino inductor de turistas del Estado. La localidad posee un flujo en fase de crecimiento debido a sus recursos naturales. El abordaje metodológico es cuantitativo y se aplicaron 154 formularios basados en una escala métrica, tipo Likert, de 11 posiciones que variaban de desacuerdo plenamente a concuerdo plenamente. El cuestionario fue elaborado en base a las dimensiones de la Teoría del Comportamiento Planeado (TCP), sumando la dimensión Apego al Lugar. Para el tratamiento de los datos recolectados se utilizaron las técnicas estadísticas de Análisis Factorial Exploratorio (AFE) y Modelo de Ecuaciones Estructurales (MEE). El resultado reveló que las dimensiones cognitivas pertenecientes a la TCP tienen un poder mayor de explicación del comportamiento ambiental de los residentes de Barra do Cunhaú, en relación a la dimensión afectiva representada por el Apego al Lugar
Antioxidant sulfated polysaccharide from edible red seaweed Gracilaria birdiae is an inhibitor of calcium oxalate crystal formation
(MDPI, 2020-04-28) Oliveira, Leticia Castelo Branco Peroba; Queiroz, Moacir Fernandes; Fidelis, Gabriel Pereira; Melo, Karoline Rachel Teodosio; Câmara, Rafael Barros Gomes da; Alves, Monique Gabriela das Chagas Faustino; Costa, Leandro Silva; Teixeira, Dárlio Inácio Alves; Melo-Silveira, Raniere Fagundes; Rocha, Hugo Alexandre de Oliveira
The genus Gracilaria synthesizes sulfated polysaccharides (SPs). Many of these SPs, including those synthesized by the edible seaweed Gracilaria birdiae, have not yet been adequately investigated for their use as potential pharmaceutical compounds. Previous studies have demonstrated the immunomodulatory effects of sulfated galactans from G. birdiae. In this study, a galactan (GB) was extracted from G. birdiae and evaluated by cell proliferation and antioxidant tests. GB showed no radical hydroxyl (OH) and superoxide (O2−) scavenging ability. However, GB was able to donate electrons in two further different assays and presented iron- and copper-chelating activity. Urolithiasis affects approximately 10% of the world’s population and is strongly associated with calcium oxalate (CaOx) crystals. No efficient compound is currently available for the treatment of this disease. GB appeared to interact with and stabilize calcium oxalate dihydrate crystals, leading to the modification of their morphology, size, and surface charge. These crystals then acquired the same characteristics as those found in healthy individuals. In addition, GB showed no cytotoxic effect against human kidney cells (HEK-293). Taken together, our current findings highlight the potential application of GB as an antiurolithic agent
Application of nitriding and duplex treatment on steel drills-HSS
(JMEST, 2020-04) Feitor, Michelle Cequeira; Serra, Petteson Linniker Carvalho; Sousa, Rômulo Ribeiro Magalhães de; Barros Neto, João Rodrigues de; Libório, Maxwell Santana; Costa, Thércio Henrique de Carvalho
The present study aims to evaluate the application of plasma nitriding (at temperatures of 450° and 500°C) and duplex treatment (conventional nitriding followed by TiN deposition, using the cathodic cage deposition technique). Samples were characterized by Vickers Microhardness Test, Scanning Electron Microscopy-SEM, and Energy Dispersion Spectroscopy-EDS. Drill performance was evaluated after machining SAE1045 steel specimens, using flank wear and hole diameter measurements. The performance test pointed to the viability of the treatment at 450°C, whose treated drill had a longer life than in the untreated drill, in addition to meeting the dimensional quality in all holes. In contrast, the other tools, nitrided at 500°C and submitted to the duplex treatment, they presented performance below the expected, not showing viability for application in these conditions. Additionally, it was observed the existence of a thermal gradient formed during the treatment
Caracterização socio-econômico-cultural de raizeiros e procedimentos pós-colheita de plantas medicinais comercializadas em Maceió, AL
(Revista Brasileira de Plantas Medicinais, 2009) Araújo, Afranio Cesar; Silva, J. P.; Cunha, J. L. X. L.; Araújo, J. L. O.
Catalytic upgrading of Elephant grass (Pennisetum purpureum Schum) pyrolysis vapor using WO3 supported on RHA and RHA-MCM-41
(Elsevier, 2017-01-01) Melo, Marcus Antônio de Freitas; Braga, Renata Martins; Melo, Dulce Maria de Araújo; Vitor Sobrinho, Eledir; Barros, Joana Maria de Farias; Carvalho, Alexandre Fontes Melo de; Fontes, Maria do Socorro Braga; Freitas, Júlio César de Oliveira
Recently, zeolites have been widely applied in catalytic pyrolysis to improve physical and chemical properties of bio-oil to produce energy or to selectively produce chemicals for industry. This study aims to analyze the catalytic pyrolysis products of Elephant Grass (EG) using WO3 catalysts supported on rice husk ash (RHA) silica and RHA-MCM-41, being low cost materials derived from agro industrial waste, and evaluate the catalysts activity in the formation of deoxygenated compounds. Elephant Grass has been shown as a potential energy crop that has fast growth and is easy to cultivate in different countries, including Brazil. Its energetic characterization was evaluated by proximate and ultimate analysis, High Heat Value (HHV), cellulose, hemicellulose and lignin content, chemical ash composition by FRX and bulk density. Pyrolysis analysis was performed at 500 ◦C in a Py-5200 HP-R connected to a GC–MS, and pyrolysis vapors were carried by N2 to a catalytic bed at 400 and 600 ◦C. It was noticed that increasing catalyst temperature promotes cracking reactions leading to increased aromatic content. The main oxygenated pyrolysis products of EG such as phenols, furans, ketones and acetic acid were converted at 600 ◦C using WO3/RHA catalyst into aromatics (benzene, toluene, xylene, styrene), being of high added value for chemical industry. The main influence on aromatics yields could be related to catalytic activity of WO3 promoted by its redox ability and the rise in temperature which favors cracking reactions
Characterization and pyrolysis of Chlorella vulgaris and Arthrospira platensis: potential of bio-oil and chemical production by Py-GC/MS analysis
(Springer Nature, 2017-04-17) Melo, Marcus Antônio de Freitas; Almeida, Hanna Nóbrega; Calixto, Guilherme Quintela; Chagas, Bruna M. E.; Melo, Dulce Maria de Araújo; Resende, Fabio M.; Braga, Renata Martins
Biofuels have been seen as potential sources to meet future energy demand as a renewable and sustainable energy source. Despite the fact that the production technology of first-generation biofuels is consolidated, these biofuels are produced from foods crops such as grains, sugar cane, and vegetable oils competing with food for crop use and agricultural land. In recent years, it was found that microalgae have the potential to provide a viable alternative to fossil fuels as source of biofuels without compromising food supplies or arable land. On this scenario, this paper aims to demonstrate the energetic potential to produce bio-oil and chemicals from microalgae Chlorella vulgaris and Arthrospira platensis. The potential of these biomasses was evaluated in terms of physical-chemical characterization, thermogravimetric analysis, and analytical pyrolysis interfaced with gas chromatograph (Py-GC/MS). The results show that C. vulgaris and A. platensis are biomasses with a high heating value (24.60 and 22.43 MJ/kg) and low ash content, showing a high percentage of volatile matter (72.49 and 79.42%). These characteristics confirm their energetic potential for conversion process through pyrolysis, whereby some important aromatic compounds such as toluene, styrene, and phenol were identified as pyrolysis products, which could turn these microalgae a potential for biofuels and bioproduct production through the pyrolysis
Characterization and thermal behavior of PrMO3 (M = Co or Ni) ceramic materials obtained from gelatin
(Elsevier, 2012-09) Aquino, Flávia de Medeiros; Melo, Dulce Maria de Araújo; Pimentel, Patrícia Mendonça; Braga, Renata Martins; Melo, Marcus Antônio De Freitas; Martinelli, Antonio Eduardo; Costa, Asenete Frutuoso
Metal oxides with perovskite-type structure have attracted considerable interest in recent years due to their magnetic and electrical properties, as well as their catalytic activity. In this study, oxides with PrNiO3 and PrCoO3 composition were prepared by using gelatin powder as a precursor agent for its use as a catalyst. The powders obtained were calcined at 700 8C and 900 8C and characterized using the X-ray diffraction, thermal analysis (thermogravimetry and differential thermal analysis), infrared spectrosco- py, temperature programed reduction and scanning electron microscopy techniques. Thermogravimetric data using the non-isothermal kinetic models of Flynn and Wall and ‘‘Model-free Kinetics’’ were used to determine the activation energy to study the decomposition kinetics of the ligand groups with system’s metallic ions that takes part in the synthesis of PrMO3 (M = Ni or Co)
A comparative study of dry reforming of methane over nickel catalysts supported on perovskite-type LaAlO3 and commercial a-Al2O3
(Elsevier, 2018-06-14) Melo, Marcus Antônio de Freitas; Figueredo, Gilvan Pereira de; Medeiros, Rodolfo Luiz Bezerra de Araújo; Macedo, Heloísa Pimenta de; Oliveira, Ângelo Anderson Silva de; Braga, Renata Martins; Mercury, José Manuel Rivas; Melo, Dulce Maria de Araújo
A systematic and comparative study was made to determine the influence of perovskite-type LaAlO3 and commercial a-Al2O3 on the performance of nickel-based catalysts in dry reforming of methane (DRM). The perovskite-type LaAlO3 was selected due to its characteristics of solid state semiconductor with oxygen vacancies and high structural stability. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), N2 adsorption-desorption, temperature programmed reduction (TPR-H2), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The catalyst performance was evaluated based on activity tests (600e800 C) and short- and long-term stability (10 and 20 h) at 700 C at a GHSV (Gas Hourly Space Velocity) of 18 and 72 L g1 h1. The TPR-H2 profiles indicate that the oxygen vacancies on the perovskite surface exerted a strong effect on the reduction temperature and reducibility of the NiO nanoparticles, resulting in weak Ni0/support interaction. The results of the tests after 10 h under GHSV of 18 L g1 h1 indicate that the Ni/LaAlO3 catalyst is 7.8 and 11.5% more stable than Ni/a-Al2O3 in the conversions of CH4 and CO2, respectively. The higher stability and activity of Ni/LaAlO3 is directly ascribed to the presence of NiO (3.38 wt%) after activation, which promoted the formation of carbon nanotubes (CNT) and increased the dispersion of the metallic phase. Even under severe conditions of activation and reaction (high GHSV), as in the long-term test, the Ni/LaAlO3 catalyst showed a 37.2% higher H2 yield than the Ni/a-Al2O3. Analyses by TEM indicate that the Ni/a-Al2O3 catalyst exhibited deactivation problems associated with sintering effects. Thus, the presence of structural defects and surfaces rich in oxygen vacancies makes LaAlO3 perovskite a potential support for application in methane catalytic reforming processes
Comparison of kinetic study of CTMA+ removal of molecular sieve Ti-MCM-41 synthesized with natural and commercial silica
(ABM, ABC, ABPol, 2015) Melo, Marcus Antônio de Freitas; Fontes, Maria do Socorro Braga; Melo, Dulce Maria de Araújo; Costa, Cintia de Castro; Braga, Renata Martins; Alves, José Antônio Barros Leal Reis
This work aimed to determine and compare the apparent activation energy, involved in thermal decomposition of CTMA+ from the pores of Ti-MCM-41 synthesized by two different source of silica in order to evaluate their influence in the template removal. The molecular sieves Ti-MCM-41 were synthesized using rice husk ash (RHA), as alternative low cost source of silica, and commercial silica gel, obtaining two mesoporous material by hydrothermal synthesis of gel molar composition of: 1.0 CTMABr: 4.0 SiO2 : X TiO2 : 1.0 Na2 O: 200.0 H2 O. The samples were characterized to compare its properties by X-ray diffraction, IR spectroscopy, BET method and thermogravimetric analysis (TGA). The kinetic study using the model proposed by Flynn and Wall to determine the apparent activation energy for CTMA+ removal was performed using TGA data. The thermogravimetric analysis results of the material obtained from RHA confirmed intrinsic properties of mesoporous MCM-41 as the synthesized with commercial silica gel, such as high specific area, mesoporous range of pore diameter and hexagonal structure. According to the kinetics results the RHA showed similar chemical interaction to commercial silica gel, which makes it an interesting material, since it is a low cost source of natural silica from agricultural waste
Efeito de diferentes fontes de sílica nos parâmetros texturais da peneira molecular MCM-41
(Associação Brasileira de Cerâmica - ABCeram, 2016) Melo, Marcus Antônio de Freitas; Fontes, Maria S. B.; Melo, Dulce Maria de Araújo; Costa, Cíntia de Castro; Alves, J. A. B. L. R.; Silva, M. L. P.; Braga, Renata Martins
Nas últimas décadas, pesquisas estão sendo desenvolvidas para obtenção de materiais eficientes e economicamente viáveis para aplicação em diversos setores da indústria. Os materiais mesoporosos da família MCM-41 estão entre os candidatos eficazes pela facilidade de síntese e estrutura que favorece uma gama de aplicações. O objetivo desse trabalho foi apresentar uma abordagem rítica das características e propriedades dos materiais mesoporosos do tipo MCM-41, enfocando nos aspectos estruturais. Além isso, foram discutidas as vantagens e desvantagens do uso de sílica comerciais e alternativas. As fontes de sílica comerciais analisadas foram sílica gel e TEOS; já as fontes de sílica alternativas foram cinza da casca de arroz, quartzo e pó de vidro. Os materiais analisados foram sintetizados pelo método hidrotérmico e caracterizados por DRX, FTIR, BET e TG. Os resultados apresentados comprovam a eficiência das fontes de sílica alternativas na síntese do MCM-41, pois os materiais apresentaram propriedades texturais dentro dos padrões exigidos. Dessa forma, eles estão aptos a serem testados na indústria em substituição aos MCM-41 sintetizados com fonte de sílica comercial
Estudo do perfil térmico de fornos do tipo "caipira" utilizados pelo setor de cerâmica vermelha em Parelhas na Região do Seridó, RN
(Sociedade de Investigações Florestais, 2015) Silva, Áurea de Paula Medeiros e; Santos, Rosimeire Cavalcante dos; Castro, Renato Vinícius Oliveira; Carneiro, Angélica de Cássia Oliveira; Paskocimas, Carlos Alberto; Marinho, George Santos
Este trabalho teve como objetivo caracterizar o perfil térmico de fornos tipo "caipira" utilizados pelo setor de cerâmica vermelha em Parelhas, na região do Seridó, RN, visando propor intervenções estruturais que possam colaborar para aumentar a produtividade e qualidade dos produtos, otimizar o consumo de madeira e mitigar as perdas durante o processo de queima. O trabalho foi desenvolvido na Cerâmica Esperança, na cidade de Parelhas, RN. Foram realizados quatro tratamentos com três repetições, sendo a argila o parâmetro utilizado como referência para distinguir os tratamentos. Foram monitorados a quantidade da lenha, a qualidade da telha e o tempo de cada queima. Foram aferidas temperaturas em 15 pontos marcados na superfície da carga enfornada, em intervalos de 30 min a partir do pré-aquecimento até o final da queima, utilizando um pirômetro de mira a laser. Os resultados indicaram que a madeira utilizada como lenha apresentou densidade sem diferença significativa entre os tratamentos, umidade dentro dos padrões permitidos e consumo heterogêneo, enquanto a argila teve pouca retração linear quando submetida ao fogo e o forno, perfil térmico heterogêneo. O parâmetro do fio, que é utilizado como referência para o controle da queima, foi significativo, embora com oscilações diferenciadas, razão por que não deve ser o único critério para finalização do processo de queimas. A parte central do forno foi a área que atingiu maiores temperaturas de maneira homogênea, com maior concentração de produtos de primeira qualidade; a curva de temperatura ideal foi do tratamento 1, com uma média de 18,66% de produto de primeira qualidade, com temperatura de 100 °C a 400 °C
Influence of porosity in a packed-bed tubular reactor on biodiesel production from soybean oil and supercritical ethanol: an experimental and phenomenological investigation
(American Chemical Society, 2019-07-31) Souza, Domingos Fabiano de Santana; Santiago, Luiz E. P.; Rebouças, Érica G.; Silva, Maxwell G.; Oliveira, Katherine C.; Jesus, Anderson A.; Aguiar, Emerson Moreira de; Oliveira, Jackson A.
In the present study, the transesterification of soybean oil with ethanol under supercritical conditions was investigated using a packed-bed tubular reactor. The experiments were performed with an oil/alcohol molar ratio of 1:40, a pressure of 15 MPa, and different conditions of temperature (573−673 K), flow rate (0.5−1.0 mL/min), and bed porosity (0.32−1.0). A phenomenological model was developed to describe and analyze the results. The highest ester yield (98.99%) was obtained for the lower bed porosity (0.32), under 673 K and 0.5 mL/min with a residence time of 5.44 min. The kinetic and dispersion coefficients were estimated using the particle swarm optimization algorithm, and the model fitted the experimental data with an R2 coefficient of 0.97. The proposed kinetic model followed the behavior of the Arrhenius equations. Low values of dispersion were observed under conditions of lower flow rate and porosity. An analysis of the model allowed us to verify that the increase of the ester yield produced occurs at small values of the Reynolds number and high Peclet numbers
Modeling and simulation of breakthrough curves during purification of two chitosanases from Metarhizium anisopliae using ion-exchange with expanded bed adsorption chromatography
(Springer Nature Switzerland, 2014-02-17) Santos, Everaldo Silvino dos; Santana, Sergio Carvalho de; Silva Filho, Raimundo Cosme da; Cavalcanti, Jorge dos Santos; Oliveira, Jackson Araujo de; Macedo, Gorete Ribeiro de; Padilha, Francine Ferreira
A mathematical model was developed to predict breakthrough curves during purification of the two chitosan- ases from Metarhizium anisopliae by expanded bed adsorption, taking into account the axial dispersion of liquid and using Streamline DEAE and SP XL adsorbents, anion and cation exchange resins, respectively. All the experiments were performed without clarification (with cells) aiming at the reduction of unit operations in future projects of separation processes, thereby reducing capital and operating costs. Chitosanases are enzymes that hydrolyze the carbohydrate chitosan, resulting in oligosaccharides that have many remarkable biological activities, such as anti-cancer, anti-HIV and antioxidant activities. The two adsorbents had similar performance in relation to hydrodynamics and mass transfer. The results of the parametric sensitivity analysis agree with the literature, and the model was validated with an average high degree of fit (94.68%) between simulated and experimental data obtained in this work
Nickel catalyst supported on magnesium and zinc aluminates (MgAl2 O4 and ZnAl2 O4 ) spinels for dry reforming of methane
(Associação Brasileira de Cerâmica - ABCeram, 2017) Melo, Marcus Antônio de Freitas; Araújo, Larissa Costa Barros de; Melo, Dulce Maria de Araújo; Barros, J. M. de F.; Braga, Renata Martins; Costa, C. de C.; Rodrigues, G.
Materials such as MgAl2O4 and ZnAl2O4 assessed in the reaction of dry reforming of methane to produce syngas were synthesized by microwave-assisted combustion method using urea as fuel. Samples of synthesized oxides were calcined at 800 °C for 2 h and impregnated with 5% nickel. The impregnated samples were calcined at 850 °C for 4 h to obtain the desired phases. The results of the catalytic tests showed that the catalysts are active for the reaction of dry reforming of methane, and the catalyst that showed the best performance for methane conversion was 5% Ni/MgAl2 O4 calcined at 850 °C/4h
One-pot microwave-assisted combustion synthesis of Ni-Al2O3 nanocatalysts for hydrogen production via dry reforming of methane
(Elsevier, 2020-03-01) Melo, Marcus Antônio de Freitas; Medeiros, Rodolfo Luiz Bezerra de Araújo; Figueredo, Gilvan Pereira de; Macedo, Heloísa Pimenta de; Oliveira, Ângelo Anderson Silva de; Rabelo Neto, Raimundo C.; Melo, Dulce Maria de Araújo; Braga, Renata Martins
Ni-based catalysts supported on Al2O3 were obtained via a simple, low cost and fast one-pot microwave-assisted combustion synthesis. The effect of fuel content (urea) was investigate. It was observed that the fuel ratio greatly influences the catalysts properties and performance. The results showed that the catalyst synthesized with low fuel content (Ni-LU) presented high specific surface area (265 m2/g), high degree of reduction and smaller nanometric Ni particles (~15 nm). In addition, the catalytic tests carried out at 700 °C for 20 h (GHSV = 72 Lh−1g−1) revealed high activity with low coke deposition. Further investigations were conducted on Ni-LU catalyst in order to better understand its catalytic properties. In-situ X-ray diffraction analysis (using synchrotron radiation) was used to evaluate the Ni particle size during the DRM, and indicated the sintering of Ni particles during the first hour of catalytic reaction. Furthermore, small amount of carbon nanotubes (CNT) with Ni particles encapsulated were observed by TEM analysis
One-step synthesis of LaNiO3 with chitosan for dry reforming of methane
(Elsevier, 2018-05-17) Melo, Marcus Antônio de Freitas; Oliveira, Ângelo Anderson Silva de; Medeiros, Rodolfo Luiz Bezerra de Araújo; Figueredo, Gilvan Pereira de; Macedo, Heloísa Pimenta de; Braga, Renata Martins; Maziviero, Fernando Velcic; Melo, Dulce Maria de Araújo; Vieira, Marcela Marques
This paper presents a new preparation method of a catalytic precursor LaNiO3 perovskite type in one-step using chitosan as a chelating agent. During synthesis La and Ni nitrates were added into a solution containing chitosan, placed into an oven to decompose the reagents and subsequently calcined. The perovskite was characterized by X-ray diffraction (XRD), scanning electron microscopy with chemical microanalysis (SEM-EDS), temperature-programmed reduction (TPR) and thermogravimetric analysis (TGA). The catalytic tests were conducted in a space velocity of 18 Lh1 g1 at three temperatures: 600, 700 and 800C. The characterization results indicated the formation above 95% of LaNiO3 phase with good chemical homogeneity at lower temperature with metallic area and dispersion compatible with literature. The catalytic test results showed good levels of CH4 and CO2 conversions and good yields of CO and H2. Therefore, the described method is a simple, fast and low-cost route to prepare LaNiO3 for hydrogen production via dry reforming of methane
Optical-electrical properties and thickness analysis of TiO2 thin films obtained by magnetron sputtering
(Springer Science and Business Media LLC, 2020-09-23) Feitor, Michelle Cerqueira; S. Sobrinho, V. S.; Miranda Neto, José Queiroz de; Lima, L. L. F.; Souza, Iedo A; Libório, Maxwell Santana; Queiroz, José César Augusto de; Sousa, Rômulo Ribeiro Magalhães de; Almeida, Érika Oliveira de; Costa, Thércio Henrique de Carvalho
The study of thin films with properties that meet specific needs and improve people’s quality of life has been the focus of many researchers. However, knowing and controlling the production techniques of these films have been a challenge for the industry of optical-electronic devices, functional coatings, and energy conservation. The thickness of thin films is a parameter that influences the optical and electrical characteristics of these materials, thus being one of the most important information in the plasma deposition process. Because of the need for precision in measuring the thickness of thin transparent films, this work proposes to evaluate the Swanepoel methods (envelope) and the PUMA, computational method, from optical transmittance curves and compare them with the measurements directly made by microscopy. Scanning electronics for thin films of TiO2 deposited by magnetron sputtering in different conditions. The results of this study showed that the PUMA method is capable of calculating film thicknesses of a few hundred nanometers and with few interference fringes. The PUMA method showed convergence with high precision for films produced with 30 and 60 min of treatment and a difference of 17% for films with 120 min of deposition concerning the measurements made by microscopy
Proposta de aplicativo de segurança compartilhada para monitoramento em comunidades: escoltap soluções de vigilância
(International Educative Research Foundation and Publisher, 2019-06-30) Barros, Edilson Melo de; Burlamaqui, Aquiles Medeiros Filgueira; Silva, Igor Rosberg de Medeiros; Medeiros, Igor Rosberg de; Medeiros, Henrique Rocha de; Florentino, Davidson Rogério de Medeiros
Insecurity is a public problem and is commonly present in the population's daily lives. It is notorious that many people seek alternatives to minimize or avoid situations that cause risks to them or their loved ones. Technology proves to be an efficient tool in this scenario, since it assists in diverse situations and in a fast and practical way. The present work aims to ally the technology with the problematic of the lack of security, through the creation of a mobile application, with the purpose of providing the end user with a proposal of help in adverse situations. The application can be used by anyone who has a mobile phone with an Android or IOS operating system. The ultimate goal of the application is to provide clients with a useful alternative so that they can mitigate the problems of personal insecurity on their return home, relying on the support of their family members or contracted services, such as private or street security. For the implementation of the project, tests are in progress, ensuring that all particularities are examined, before feasibility and final disclosure of the application
Recuperação de proteína do soro de queijo de coalho, por adsorção em leito expandido, utilizando resina de troca aniônica e catiônica
(Revista Higiene Alimentar, 2012) Santos, Everaldo Silvino dos; Cavalcanti, Jorge dos Santos; Soares, Jardelson César; Macedo, Gorete Ribeiro de
O presente trabalho teve como objetivo recuperar e purificar proteínas presentes no soro de queijo tipo coalho, através da técnica de adsorção em leito expandido, utilizando resinas de troca aniônica Streamline® DEAE e troca catiônica Streamline® SP. Experimentos iniciais permitiram avaliar a adsorção das proteínas para as resinas usando tanques agitados. Nos experimentos em leito expandido, foi utilizada uma coluna de 2,6 cm de diâmetro por 30 cm de altura, acoplada a uma bomba peristáltica. Uma amostra de solução de soro (250 mL) foi aplicada a uma coluna contendo a resina (25 mL) previamente equilibrada em tampão Tris/HCl (50 mM, pH 7,0), após aplicação da amostra e da lavagem, efetuou-se a eluição, à temperatura ambiente, adicionando-se NaCl (1,0 M) ao tampão Tris/HCl (50 mM, pH 7,0). Os resultados dos experimentos em tanques agitados mostraram que para as três condições iniciais de concentração de proteína a quantidade adsorvida na fase sólida foi de 249,2 mg/mL de adsorvente, 9,4 mg/mL de adsorvente e 14,4 mg/mL de adsorvente e de 291,0 mg/mL de adsorvente, 6,3 mg/mL de adsorvente e 3,9 mg/mL de adsorvente para as resinas Streamline® DEAE e Streamline® SP, respectivamente, correspondendo aos valores de aproximadamente 71,6%, 6,8% e 21,8% e 83,6%, 4,6% e 5,9% de recuperação das proteínas inicialmente existentes, para as resinas Streamline® DEAE e Streamline® SP, respectivamente. Experimentos usando o leito na forma expandida mostraram que é possível recuperar aproximadamente 16% e 23%, respectivamente, para as duas resinas
Recuperação de proteína do soro de leite bovino usando cromatografia de interação hidrofóbica em leito expandido
(Revista Higiene Alimentar, 2009) Santos, Everaldo Silvino dos; Cavalcanti, Jorge dos Santos; Magalhães, Margarida Maria dos Anjos
O presente trabalho teve por objetivo estudar a adsorção das proteínas do soro de queijo tipo “coalho” para a resina de interação hidrofóbica StreamlineTM Phenyl usando o leito na forma expandida. Foi utilizada uma coluna de 2,6 cm de diâmetro por 30 cm de altura, acoplada a uma bomba peristáltica. Uma amostra de solução de soro (250 mL) foi aplicada a uma coluna contendo a resina StreamlineTM Phenyl (25 mL) previamente equilibrada em tampão Tris/HCl (50 mM, pH 7,0) com NaCl (1,0 M), após lavagem a eluição foi conduzida a temperatura ambiente em tampão Tris/HCl (50 mM, pH 7,0) e altura de leito fixo de 5,0 cm. Os resultados mostraram que foi possível recuperar 37% das proteínas inicialmente contidas no soro em uma única etapa

SIGAA

Navegar

Navegando EAJ - Artigos publicados em periódicos por Título