30 resultados para paint emulsions
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex® 355; Tween® 80; Spam® 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q®). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way
Resumo:
The fat acid esters and tocopherolic derivatives are of great economic interest in many industries. The sunflower oil, which had its rich constitution in these composites, is a very interesting raw material source for the job in some sectors as bio-carburants, bio-lubrificants, bio-surfactants, dispersing agents, food industries, medicines and cosmetics. A system emulsified steady from this oil can wide be used in the therapeutical one, therefore it is of easy acceptance for the patient, for being pharmaceutical forms that allow a better medicine administration. The chemical composition characteristics, rich in unsaturad fat acid and tocopherolic derivatives, the sunflower oil, make of the emulsified systems contend this oil a proposal promising for formularizations of pharmaceutical and cosmetic use with antirust and photoprotection. The general objective of this work was to apply the HLB beddings to determine the sunflower oil critical HLB and, from this, to be able to evaluate the ideal mixture of the constituent of this system through the study of the ternary diagrams for the determination of the ratio of constituent that will generate the emulsion most steady
Resumo:
Natural oils have shown a scientific importance due to its pharmacological activity and renewable character. The copaiba (Copaifera langsdorffii) and Bullfrog (Rana catesbeiana Shaw) oils are used in folk medicine particularly because the anti-inflammatory and antimicrobial activities. Emulsion could be eligible systems to improve the palatability and fragrance, enhance the pharmacological activities and reduce the toxicological effects of these oils. The aim of this work was to investigate the antimicrobial activity of emulsions based on copaiba (resin-oil and essential-oil) and bullfrog oils against fungi and bacteria which cause skin diseases. Firstly, the essential oil was extracted from copaiba oil-resin and the oils were characterized by gas chromatography coupled to a mass spectrometry (GC-MS). Secondly, emulsion systems were produced. A microbiological screening test with all products was performed followed (the minimum inhibitory concentration, the bioautography method and the antibiofilm determination). Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Candida albicans, C. parapsilosis, C. glabrata, C. krusei and C. tropicalis American Type Culture Collection (ATCC) and clinical samples were used. The emulsions based on copaiba oil-resin and essential oil improved the antimicrobial activity of the pure oils, especially against Staphylococcus e Candida resistant to azoles. The bullfrog oil emulsion and the pure bullfrog oil showed a lower effect on the microorganisms when compared to the copaiba samples. All the emulsions showed a significant antibiofilm activity by inhibiting the cell adhesion. Thus, it may be concluded that emulsions based on copaiba and bullfrog oils are promising candidates to treatment of fungal and bacterial skin infections
Resumo:
Praziquantel (PRZ) is the main drug used for treatment of schistosomiasis in Brazil. It is administered by oral rout as tablets. However, has low aqueous solubility which limits this therapeutic success dosage form and availability of liquid forms. The emulsion systems have great potential and represent an interesting strategy to increase the solubility of drugs. The aim of study was the development and characterization of lipid-emulsified liquid systems of the type oil in water (O / W), the base of soybean oil as the internal phase stabilized by surfactants pair Tween® 80 and Span® 80, for improving the phase biopharmaceutical of PRZ. After selecting the best value of Hydrophilic-Lipophilic Balance (HLB = 11), the parameters of the preparation of the formulations were optimized emulsification technique. The emulsions were successfully obtained; the liquid forms provided exhibited Newtonian behavior and an increase in solubility of PRZ higher than 20 times. The accelerated stability study demonstrated the stability of the emulsions and the effect of cosurfactants investigated. The study of the dynamics of interaction between components in the diagram showed pseudoternary phase regions to obtain O/W emulsions, whereas the study of the interaction of the components and their effect on system structure and the efficiency of incorporation of the drug led to systems with an amount of soluble drug even higher (about 1.5%), which demonstrates the potential of this new input mainly for the treatment of schistosomiasis, which resulted in the filing of patent BR 10 2013 0004 55 3
Resumo:
This work aims give evidence of that The hope principle, the philosophical system devised by the German philosopher Ernst Bloch, in which hope assumes an ontological character, offers cognitive support that allows overcoming the void imposed by nihilism today, especially in the field of education. But while it offers cognitive support, it also presents a need that is fulfilled by an educational proposal based on a not-yet-conscious being. An education based on hope has four essential pillars: learning to know, learning to do, learning to be, learning to live together and, most of all, immerging into in the seas of uncertainty. In times when school is a promoter of certainties at the expense of uncertainties, education must not forsake the notion of the unpredictable and immeasurable, nor the need to find ways to enable better understanding of aspect related to the not-yet-be. The employed theoretical and methodological elements in this work paint a corpus through an interactive process in which layers of additional texts are subjected to analysis
Resumo:
It presents a solar collector to be used in a system for heating water for bathing, whose main characteristics are its low cost and easy manufacturing and assembly. The absorbing surface of the collector is formed by an aluminum plate with eight flaps where they lodge PVC pipes. The catchment area of solar radiation corresponds to 1.3 meters. The collector box was made of wood, is covered by transparent glass and thermal insulation of tire chips and expanded polystyrene (EPS). Absorber tubes were connected in parallel through the use of PVC fittings and fixed to the plate by the use of metal poles and rivets. The entire absorber received paint flat black for better absorption of sunlight. The system worked on a thermosiphon assembly and absorber of the collector has been tested in two configurations: with the tubes facing up, directly exposed to the impact of sunlight and facing down, exchanging heat with the plate by conduction. It was determined the most efficient configuration for the correct purpose. The solar collector was connected to a thermal reservoir, also alternative, low-cost forming the system of solar water heating. We evaluated thermal parameters that proved the viability of the heating system studied
Resumo:
In the petroleum industry, water is always present in the reservoir formation together with petroleum and natural gas and this fact provokes the production of water with petroleum, resulting in a great environmental impact. Several methods can be applied for treatment of oily waters, such as: gravitational vases, granulated media filtration systems, flotation process, centrifugation process and the use of hydrocyclones, which can also be used in a combined way. However, the flotation process has showed a great efficiency as compared with other methods, because these methods do not remove great part of the emulsified oil. In this work was investigated the use of surfactants derived from vegetable oils, OSS and OGS, as collectors, using the flotation process in a glass column with a porous plate filter in its base for the input of the gaseous steam. For this purpose, oil/water emulsions were prepared using mechanical stirring, with concentrations around 300 ppm. The air flow rate was set at 700 cm3/min and the porous plate filter used for the generation of the air bubbles has pore size varying from 16 to 40 Pm. The column operated at constant volume (1500mL). A new methodology has been developed to collect the samples, where, instead of collecting the water phase, it was collected the oil phase removed by the process in the top of the flotation column. It has been observed that it is necessary to find an optimum surfactant concentration to achieve enhanced removal efficiency. Being for OSS 1.275 mmol/L and for OGS 0.840 mmol/L, with removal efficiencies of 93% and 99%, respectively, using synthetic solutions. For the produced water, the removal in these concentrations was 75% for OSS and 65% for OGS. It is possible to remove oil from water in a flotation process using surfactants of high HLB, fact that is against the own definition of HLB (Hydrophile-Lipophile Balance). The interfacial tension is an important factor in the oil removal process using a flotation process, because it has direct interference in the coalescence of the oil drops. The spreading of the oil of the air bubble should be considered in the process, and for the optimum surfactant concentrations it reached a maximum value. The removal kinetics for the flotation process using surfactants in the optimum concentration has been adjusted according to a first order model, for synthetic water as for the produced water.
Resumo:
Petroleum can be associated or not with natural gas, but in both cases water is always present in its formation. The presence of water causes several problems, such as the difficulty of removing the petroleum from the reservoir rock and the formation of waterin-oil and oil-in-water emulsions. The produced water causes environmental problems, which should be solved to reduce the effect of petroleum industry in the environment. The main objective of this work is to remove simultaneously from the produced water the dispersed petroleum and dissolved metals. The process is made possible through the use of anionic surfactants that with its hydrophilic heads interacts with ionized metals and with its lipophilic tails interacts with the oil. The studied metals were: calcium, magnesium, barium, and cadmium. The surfactants used in this research were derived from: soy oil, sunflower oil, coconut oil, and a soap obtained from a mixture of 5wt.% coconut oil and 95wt.% animal fat. It was used a sample of produced water from Terminal de São Sebastião, São Paulo. As the concentration of the studied metals in produced water presented values close to 300 mg/L, it was decided to use this concentration as reference for the development of this research. Molecular absorption and atomic absorption spectroscopy were used to determine petroleum and metals concentrations in the water sample, respectively. A constant pressure filtration system was used to promote the separation of solid and liquid phases. To represent the behavior of the studied systems it was developed an equilibrium model and a mathematical one. The obtained results showed that all used surfactants presented similar behavior with relation to metals extraction, being selected the surfactant derived from soy oil for this purpose. The values of the partition coefficients between the solid and liquid phases " D " for the studied metals varied from 0.2 to 1.1, while the coefficients for equilibrium model " K " varied from 0.0002 and 0.0009. The removal percentile for oil with all metals associated was near 100%, showing the efficiency of the process
Resumo:
The tanning industries are those which transform animal hide or skin into leather. Due to the complexity of the transformation process, greater quantities of chemicals are being used which results in the generation of effluents with residual solids. The chromium in the residual waters generated by tanning tend to be a serious problem to the environment, therefore the recovery of this metal could result in the reduction of manufacturing costs. This metal is usually found in a trivalent form which can be converted into a hexavalent compound under acidic conditions and in the presence of organic matter. The present study was carried out with the objective to recover chromium through an extraction/re-extraction process using micro emulsions. Micro emulsions are transparent and thermodynamically stable system composed of two immiscible liquids, one forming the continuous phase and the other dispersed into micro bubbles, established by an interfacial membrane formed by surface active and co-surface active molecules. The process of recovering the chromium was carried out in two stages. The first, an extraction process, where the chromium was extracted in the micro emulsion phase and the aqueous phase in excess was separated. In the second stage, a concentrated acid was added to the micro emulsion phase rich in chromium in order to obtain a Winsor II system, where the water that formed in the micro emulsion phase separates into a new micro emulsion phase with a higher concentration of chromium, due to the lowering of the hydrophiles as well as the ionisation of the system. During the experimental procedure, a study was initiated with a synthetic solution of chromium sulphate passing onto the effluent. A Morris extractor was used in the extraction process. Tests were carried out according to the plan and the results were analysed by statistical methods in order to optimise the main parameters that influence the process: the total rate of flow (Q), stirring speed (w) and solvent rate (r). The results, after optimization, demonstrated that the best percentuals in relation to the chromium extraction (99 %) were obtained in the following operational conditions: Q= 2,0 l/h, w= 425 rpm and r= 0,375. The re-extraction was carried out at room temperature (28 °C), 40 °C and 50°C using hydrochloric acid (8 and 10 M) and sulphuric acid (8 M) as re-extracting agents. The results obtained demonstrate that the process was efficient enough in relation to the chromium extraction, reaching to re-extraction percentage higher than 95 %.
Resumo:
The increasing demand for asphalt leads to the development of techniques that can improve the quality of products and increase the useful working life of pavements. Consequently, there is a growing application of asphalt emulsions, which are produced from a mixture of petroleum asphalt cement (CAP) with an aqueous phase. The main advantage of asphalt emulsions is its cold application, reducing energy costs. Conventional emulsions are obtained using asphalt, water, solvent, and additives. The modified asphalt emulsion is developed by adding a modifying agent to conventional emulsions. These modifiers can be natural fibers, waste polymers, nanomaterials. In this work modified asphalt emulsion were obtained using organoclays. First, it was prepared a conventional asphalt emulsion with the following mass proportion: 50% of 50/70 penetration grade CAP, 0.6% of additives and 3% of emulsifier, 20% of solvent and 26.4% of water. It was used bentonite and vermiculite (1% and 4%) to obtain the modified asphalt emulsion. Bentonite and vermiculite were added in its raw state and as an organoclay form and as an organoclay-acid form, resulting in 26 experimental runs. The methodology described by Qian et al. (2011), with modifications, was used to obtain the organoclay and the organoclay-acid form. infrared spectroscopy (IR)) were used to characterize the clays and nanoclays. The emulsions were prepared in a colloidal mill, using 30 minutes and 1 hour as mixing time. After, the emulsions were characterized. The following tests were performed, in accordance with the Brazilian specifications (DNER- 369/97): sieve analysis, Saybolt Furol viscosity, pH determination, density, settlement and storage stability, residue by evaporation, and penetration of residue. Finally, it can be concluded that the use of nanoclays as asphalt modifiers represent a viable alternative to the road paving industry
Resumo:
Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1° order
Resumo:
The industry, over the years, has been working to improve the efficiency of diesel engines. More recently, it was observed the need to reduce pollutant emissions to conform to the stringent environmental regulations. This has attached a great interest to develop researches in order to replace the petroleum-based fuels by several types of less polluting fuels, such as blends of diesel oil with vegetable oil esters and diesel fuel with vegetable oils and alcohol, emulsions, and also microemulsions. The main objective of this work was the development of microemulsion systems using nonionic surfactants that belong to the Nonylphenols ethoxylated group and Lauric ethoxylated alcohol group, ethanol/diesel blends, and diesel/biodiesel blends for use in diesel engines. First, in order to select the microemulsion systems, ternary phase diagrams of the used blends were obtained. The systems were composed by: nonionic surfactants, water as polar phase, and diesel fuel or diesel/biodiesel blends as apolar phase. The microemulsion systems and blends, which represent the studied fuels, were characterized by density, viscosity, cetane number and flash point. It was also evaluated the effect of temperature in the stability of microemulsion systems, the performance of the engine, and the emissions of carbon monoxide, nitrogen oxides, unburned hydrocarbons, and smoke for all studied blends. Tests of specific fuel consumption as a function of engine power were accomplished in a cycle diesel engine on a dynamometer bench and the emissions were evaluated using a GreenLine 8000 analyzer. The obtained results showed a slight increase in fuel consumption when microemulsion systems and diesel/biodiesel blends were burned, but it was observed a reduction in the emission of nitrogen oxides, unburned hydrocarbons, smoke index and f sulfur oxides
Resumo:
The main objective of this research was the development and characterization of conventional and modified cationic asphalt emulsions. The asphalt emulsions were developed by using the Petroleum Asphalt Cement (CAP 50-70) from Fazenda Belém (Petrobras -Aracati-Ce). The first step in this research was the development of the oil phase (asphalt + solvent) and the aqueous phase (water + emulsifying agent + acid + additives), separately. During the experiments for the obtaining of the conventional asphalt emulsion, the concentration of each constituent was evaluated. For the obtaining of the oil phase, kerosene was used as solvent at 15 and 20 wt.%. For the development of the aqueous phase, the emulsifying agent was used at 0.3 and 3.0 wt.%, whereas the acid and the additive were set at 0.3 wt.%. The percentage of asphalt in the asphalt emulsion was varied in 50, 55, and 60 wt.% and the heating temperature was set at 120 °C. The aqueous phase in the asphalt emulsion was varied from 16.4 to 34.1 wt.% and the heating temperature was set at 60 °C. After the obtaining of the oil and the aqueous phases, they were added at a colloidal mill, remaining under constant stirring and heating during 15 minutes. Each asphalt emulsion was evaluated considering: sieve analysis, Saybolt Furol viscosity, pH determination, settlement and storage stability, residue by evaporation, and penetration of residue. After the characterization of conventional emulsions, it was chosen the one that presented all properties in accordance with Brazilian specifications (DNER-EM 369/97). This emulsion was used for the development of all modified asphalt emulsions. Three polymeric industrial residues were used as modifier agents: one from a clothing button industry (cutouts of clothing buttons) and two from a footwear industry (cutouts of sandals and tennis shoes soles), all industries located at Rio Grande do Norte State (Brazil).The polymeric residues were added into the asphalt emulsion (1 to 6 wt.%) and the same characterization rehearsals were accomplished. After characterization, it were developed the cold-mix asphalts. It was used the Marshall mix design. For cold-mix asphalt using the conventional emulsion, it was used 5, 6 and 7 wt.% asphalt emulsion. The conventional mixtures presented stability values according Brazilian specification (DNER-369/97). For mixtures containing asphalt modified emulsions, it was observed that the best results were obtained with emulsions modified by button residue
Resumo:
Broadly speaking, the concept of gene therapy involves the transfer of a genetic material into a cell, tissue, or organ in order to cure a disease or at least improve the clinical status of a patient. Making it simple, gene therapy consists in the insertion of functional genes into cells containing defective genes by substituting, complementing or inhibiting them. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, it is a key issue to create systems able to transfer and protect the DNA until it reaches the target, the vectors. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easily produced, present controllable stability and enable transfection. The aim of this work was to develop an emulsion for gene therapy and evaluate its ability to compact nucleic acids by the development of a complex with the plasmid pIRES2-EGFP. The first step was to determine the Hydrophilic Lipophilic Balance (HLB) of the Captex® 355 (oily internal phase of the emulsion) through long and short term stability assays. Based on the results, emulsions composed of Captex® 355, Tween 20® and Span 60® with 10.7 HLB were produced by three different methods: phase inversion, spontaneous emulsification and sonication. The results showed that the lowest diameter and best stability of the emulsions were achieved by the sonication method. The cationic emulsions were made by adding DOTAP to the basic emulsion. Its association with pIRES2-EGFP was evaluated by electrophoresis. Several rates of emulsion and DNA were evaluated and the results showed that 100% of the complex was formed when the rate DOTAP/DNA(nmol/µg) was 130. In conclusion, the overall results show the ability of the proposed emulsion to compact pIRES2-EGFP, which is a requirement to a successful transfection. Therefore, such formulation may be considered a promising candidate for gene therapy
Resumo:
This work, from a perspective that thinks the space as a historical category, and especially as a relationship which stresses the role of objects, proposes an analysis of the construction of a Republican memory in the city of Natal in the early twentieth century. This research will focus mainly on two objects: the obelisk opened in 1917, and the Andre de Albuquerque Square on the occasion of the celebration of Frei Miguelinho´s death centenary and the paint Julgamento de Frei Miguelinho ordered by the State Government to the painter Antonio Parreiras, picture that was in the Salão Nobre do Palácio do Poder Executivo of that time. In a geral way this work intend to analyse the construction of this memory as well as the role of these objects in this process. To achieve that, we propose to trace ways and networks to follow the possible associations(between people, events, images, discourses, objects, institutios etc.) in the constitution of mutual belongings. Thus, our procedure was to follow these objects through the pathways in which they became possible, so that in the end we could defend the idea that they are active participants of the process that establish them.