629 resultados para Wool shearing
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We used the fabrics of two granite plutons and U/Pb (SHRIMP) zircon ages to constrain the tectonic evolution of the E-trending Patos shear zone (Borborema Province, NE Brazil). The pre-tectonic Teixeira batholith consists of an amphibole leucogranite locally with aegirine-augite. Zircons from a syenogranite yielded crystallization ages of 591 +/- 5 Ma. The batholith fabrics were determined by anisotropy of magnetic susceptibility (AMS) and mineral shape preferred orientation. The fabrics support pre-transcurrent batholith emplacement, as evidenced by: (i) magmatic/magnetic fabrics in low susceptibility (<0.35 mSI) leucogranites highly discordant to the regional host rock structure, and (ii) concordant magnetic fabrics restricted to high susceptibility (>1 mSI) corridors connected to shear zones branching off from Patos. One of these satellite shear zones controlled the syntectonic emplacement of the Serra Redonda pluton, which yields a crystallization age of 576 +/- 3 Ma. This late shearing event marks the peak regional deformation that, south of Patos, was coupled to crustal shortening nearly perpendicular to the shear belt. The chronology of the deformational events indicates that the major shear zones of the eastern Borborema are late structures active after the crustal blocks amalgamated. (C) 2007 Elsevier Ltd. All rights reserved.
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A cathodically pretreated boron-doped diamond electrode was used for the simultaneous anodic determination of ascorbic acid (AA) and caffeine (CAF) by differential pulse voltammetry Linear calibration curves (r = 0 999) were obtained from 1 9 x 10(-5) to 2 I x 10(-4) mol L(-1) for AA and from 9 7 x 10(-6) to 1 1 x 10-4 mol L(-1) for CAF. with detection limits of 19 wool L(-1) and 7 0 mu nol L(-1). respectively This method was successfully applied for the determination of AA and CAF in pharmaceutical formulations. with results equal to those obtained using a HPLC reference method
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In this project, Stora Enso’s newly developed building system has been further developed to allow building to the Swedish passive house standard for the Swedish climate. The building system is based on a building framework of CLT (Cross laminated timber) boards. The concept has been tested on a small test building. The experience gained from this test building has also been used for planning a larger building (two storeys with the option of a third storey) with passive house standard with this building system. The main conclusions from the project are: It is possible to build airtight buildings with this technique without using traditional vapour barriers. Initial measurements show that this can be done without reaching critical humidity levels in the walls and roof, at least where wood fibre insulation is used, as this has a greater capacity for storing and evening out the moisture than mineral wool. However, the test building has so far not been exposed to internal generation of moisture (added moisture from showers, food preparation etc.). This needs to be investigated and this will be done during the winter 2013-14. A new fixing method for doors and windows has been tested without traditional fibre filling between them and the CLT panel. The door or window is pressed directly on to the CLT panel instead, with an expandable sealing strip between them. This has been proved to be successful. The air tightness between the CLT panels is achieved with expandable sealing strips between the panels. The position of the sealing strips is important, both for the air tightness itself and to allow rational assembly. Recurrent air tightness measurements show that the air tightness decreased somewhat during the first six months, but not to such an extent that the passive house criteria were not fulfilled. The reason for the decreased air tightness is not clear, but can be due to small movements in the CLT construction and also to the sealing strips being affected by changing outdoor temperatures. Long term measurements (at least two years) have to be carried out before more reliable conclusions can be drawn regarding the long term effect of the construction on air tightness and humidity in the walls. An economic analysis comparing using a concrete frame or the studied CLT frame for a three storey building shows that it is probably more expensive to build with CLT. For buildings higher than three floors, the CLT frame has economic advantages, mainly because of the shorter building time compared to using concrete for the frame. In this analysis, no considerations have been taken to differences in the influence on the environment or the global climate between the two construction methods.
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A obtenção de ligas metálicas em forma de pasta, com propriedades tixotrópicas apropriadas para serem utilizadas em processos de tixoconformação, pode ser realizada através de vários processos metalúrgicos. Destacam-se os processos de reofundidos obtidos a partir do líquido com a agitação mecânica do banho, ao longo da solidificação. Esses processos utilizam-se de rotores e propulsores, agitação mecânica usando o processo de duplo-parafuso e a agitação magneto hidrodinâmica. Outros procedimentos para a obtenção de pastas reofundidas a partir do líquido são o processo SCR (Shearing Cooling Roll), refino químico, ultra-som, processo spray, a nova reofundição NCR (New Rheocasting) e a reofundição elementar. As estruturas tixofundidas são obtidas a partir do metal sólido no qual, utiliza-se a refusão parcial de estruturas dendríticas, a fusão parcial de estruturas dendríticas deformadas (SIMA) e a fusão parcial sob pressão de estruturas dendríticas. No Trabalho em questão foram estudados os dois métodos para a obtenção de estruturas com propriedades tixotrópicas (Reofundição e Tixofundição). O primeiro processo explorado foi a agitação mecânica da liga AA7075 em seu estado semi-sólido, através de uma haste propulsora com pás recobertas por carbeto de cromo e contida em um cadinho especial de grafite. O segundo, foi a aplicação de tratamento isotérmico usando diversos patamares de tempos de aplicação e temperaturas. Este processo foi realizado por aquecimento indutivo na mesma liga AA7075, deformada anteriormente por extrusão direta. As microestruturas foram caracterizadas através dos diâmetros e formas dos glóbulos, utilizando o fator de forma específico em um programa de análise de imagens.
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Although there are a wide variety of additives that act in fresh state, to adjust the properties of cement, there is also a search by additions that improve the tenacity of the cement in the hardened state. This, in turn, can often be increased by inserting fibers, which act on the deflection of microcracks. This study aimed to use a microfiber glass wool (silica-based) as an additive reinforcing the cement matrix, improving the rupture tenacity, in order to prevent the propagation of microcracks in the cement sheath commonly found in oil wells submitted to high temperatures. The fibers were added at different concentrations, 2 to 5% (BWOC) and varied average sizes, grinding for 90 s, 180 s, 300 s, 600 s. The cement slurries were made with a density of 1,90 g/ cm3 (15,6 lb/gal), using Portland cement CPP- Special Class as the hydraulic binder and 40% silica flour. The characterization of the fiber was made by scanning electron microscopy (SEM), particle size by sieving, X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermogravimetry (TG / DTG). Were performed technological tests set by the API (American Petroleum Institute) by rheology, stability, free water, compressive strength, as well as testing rupture energy, elastic modulus and permeability. The characterization results showed good thermal stability of the microfiber glass wool for application in oil wells submitted to steam injection and, also, that from the particle size data, it was possible to suggest that microfibers milled up to 300 s, are ideal to act as reinforcement to the cement slurries. The rheological parameters, there was committal of plastic viscosity when larger lengths were inserted of microfiber (F90). The values obtained by free water and stability were presented according to API. The mechanical properties, the incorporation of microfiber to the cement slurries gave better rupture tenacity, as compared to reference cement slurries. The values of compressive strength, elastic modulus and permeability have been maintained with respect to the reference cement slurries. Thus, cement slurries reinforced with microfiber glass wool can ensure good application for cementing oil wells submitted to steam injection, which requires control of microcracks, due to the thermal gradients
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To characterize patients according to gender, age category, internment time, diagnostical hypothesis and location of the pressure ulcer; to identify the susceptibility conditions, intrinsical and extrinsical factors present on ICU patients and to verify on the existence of association between the susceptibility conditions and the intrinsecal and extrinsecal factors on the occurrence of PU. Methods: It is a descriptive study, of longitudinal design of the panel type, with quantitative approach, performed on two ICU s of a private hospital located in Natal/RN, with 40 patients interned at these units. The data collection was performed on all three shifts through a structured observation and physical exam of the patients' skin form seeking to identify the presence of PU. Results: The greatest occurence of PU was on individuals of the male gender (70%) when compared to the female gender (30%), that difference being statistically significant (p=0,0267), with the male gender presenting 4,3 times greater chance of developing PU than the female; the predominant age category was from 60 years of age on (85%), 60,0% presented 1 to 2 PU s after 7 (seven) days of permanence in the ICU s, the predominant diagnostical hypothesis on the patients with PU were the respiratory diseases (42,3%) and the most frequent locations of PU were the sacral region (40,0%) and heels (36,0%). 25 PU s of stage I were diagnosed on 50,0% of the followed patients, with general incidence of 50,0% on both ICUs. from the 88 variables researched, 75 were identified on the patients from the study, being the predominant conditions (anemia, hypotension, leukocytosis, other diseases hypertension blood pressure, cardiac insuffience, pneumonia - and ansiolythic), the intrinsecal factors (diminished muscular strenght and/or mass, discrete edema, totally compromised mobile coordination and total inability for movement on the bed) and the extrinsecal factors (inadequate mattress type, permanence on a single position for >2 hours, shearing/friction force, bed clothes with folds that leave marks on the body, pressure force) predominated on patients with PU. The male gender variables (p=0,0267,OR=4,3), sedation (p=0,0006,OR=4,1), psychomotive agitation (p=0,0375,OR=5,8) and leukocytosis (p=0,0285,OR=5,0) presented a significant statistical diference when analyzed independently. We verified an association of 17,3%, statistically significant (p=0,0384), between the susceptibility conditions (anemia, leukocytosis and hypotension), the intrinsecal factors (age equal or above 60 years, diminished/absent pain sensibility and smooth, fine or delicate skin) and the extrinsecal factors (inadequate mattress, pressure forces, shearing/friction force, permanence on a single position for more than 2 hours, elevation between 30 to 45 degrees and inadequate bed clothes' conditions), with a chance ratio of 4,6 times the risk of occurrence of PU on the patients that presented the referred association. Conclusion: The incidence of PU detected on the ICU-interned patients was high and we made evident the existence of association between the susceptibility conditions, the intrinsecal and extrinsecal factors on the occurrence of PU s on the ICUinterned patients, and thus we accept the alternative hypothesis proposed on the study
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This study evaluated the use of different probiotics, prebiotics and symbiotics on the quality of carcasses and meat of broiler chickens. One hundred and eight day-old Cobb male broilers were used (n=108) in a completely randomized design according to a 3x3 factorial, with 3 probiotics in the diet (no probiotics, probiotics 1, probiotics 2) and 3 prebiotics in the diet (no prebiotics, prebiotics 1, prebiotics 2). There were nine treatments with 4 replicates and 3 birds per replicate. The results showed that the carcass and cut yields, color (L* - lightness, a* - redness, and b* - yellowness), pH, cooking losses, shearing force and sensory analysis were not affected by the use of different growth promoters at 42 days of age. It was concluded that growth promoters supplemented to the diet did not affect the studied quantitative and qualitative parameters of the carcass and breast meat of broiler chickens.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In the last decades there was a significant increasing of the numbers of researchers that joint efforts to find alternatives to improve the development of low environmental impact technology. Materials based on renewable resources have enormous potentials of applications and are seen as alternatives for the sustainable development. Within other parameters, the sustainability depends on the energetic efficiency, which depends on the thermal insulation. Alternative materials, including vegetal fibers, can be applied to thermal insulation, where its first goal is to minimize the loss of energy. In the present research, it was experimentally analyzed the thermal behavior of fiber blankets of sisal (Agave sisalana) with and without surface treatment with oxide hidroxide (NaOH). Blankets with two densities (1100/1200 and 1300/1400 g/m2) were submitted to three rates of heat transfer (22.5 W, 40 W and 62.5 W). The analysis of the results allowed comparing the blankets treated and untreated in each situation. Others experiments were carried out to obtain the thermal conductivity (k), heat capacity (C) and the thermal diffusivity (α) of the blankets. Thermo gravimetric analyses were made to the verification of the thermal stability. Based on the results it was possible to relate qualitatively the effect of the heat transfer through the sisal blankets subjected to three heat transfer rates, corresponding to three temperature values (77 °C, 112 °C e 155 °C). To the first and second values of temperature it was verified a considerable reduction on the rate of heat transfer; nevertheless, to the third value of temperature, the surface of the blankets (treated and untreated) in contact with the heated surface of the tube were carbonized. It was also verified, through the analyses of the results of the measurements of k, C e α, that the blankets treated and untreated have values near to the conventional isolating materials, as glass wool and rock wool. It could be concluded that is technically possible the use of sisal blankets as constitutive material of thermal isolation systems in applications where the temperature do not reach values greater than 112 ºC
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They are in this study the experimental results of the analysis of thermal performance of composite material made from a plant matrix of polyurethane derived from castor oil of kernel of mamona (COF) and loading of clay-mineral called vermiculite expanded. Bodies of evidence in the proportions in weight of 10%, 15% and 20% were made to determine the thermal properties: conductivity (k), diffusivity (ά) and heat capacity (C), for purposes of comparison, the measurements were also performed the properties of polyurethane of castor without charge and also the oil polyurethane (PU), both already used in thermal insulation. Plates of 0.25 meters of material analyzed were manufactured for use as insulation material in a chamber performance thermal coverage. Thermocouples were distributed on the surface of the cover, and inside the material inside the test chamber and this in turn was subjected to artificial heating, consisting of a bank of incandescent lamps of 3000 w. The results obtained with the composite materials were compared with data from similar tests conducted with the camera alone with: (a) of oil PU, (b) of COF (c) glass wool, (d ) of rock wool. The heat resistance tests were performed with these composites, obtaining temperature limits for use in the range of 100 º C to 130 º C. Based on the analysis of the results of performance and thermal properties, it was possible to conclude that the COF composites with load of expanded vermiculite present behavior very close to those exhibited by commercial insulation material
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The process of recycling has been stimulated by the markets for several reasons, mainly on economical and environmental. Several products have been developed from recycled materials that already exist as well as several residues have been studied in different forms of applications. The greater majority of the applications for thermal insulation in the domestic, commercial and industrial systems have been elaborated in the temperature ranges between low to medium reaching up to 180oC. Many materials such as glass wool, rock wool, polystyrene are being used which are aggressive to the environment. Such materials in spite of the effectiveness in the retention of heat flow, they cost more and when discarded take several years to be absorbed by the nature. This way, in order to adapt to a world politics concerning the preservation of the environment, the present study was intended to develop a material composed of natural/biodegradable materials and industrial residues. The development of such a product in the form of a composite material based on tyre scrapes and latex for thermal insulation is presented in this research work. Thermal and physical properties of the tire scrapes as well as latex were studied in order to use them as raw materials for the manufacture of the intended composite to be applied as a thermal insulator in hot and cold systems varying between 0ºC and 200oC, respectively. Composite blankets were manufactured manually, in weight proportions of 1:1 (50:50%); 1:2 (33:67%) and 2:1 (67:33%) (tire scrapes: latex) respectively. Physical, mechanical and thermal properties of the composites were analyzed to obtain data about the viability of using the composite as a thermal insulator. The analyses carried out were based on standards ABNT, ASTM and UL. The maximum temperature obtained for the composite as a thermal insulator was 200ºC, which meets the range of applications that could be used as a thermal insulator in domestic as well as industrial purposes. The experimental results prove that the composite can be used as a thermal insulator on heated or cooled surface
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The standardization of the bovine skin thickness in the leather industry generates a residue known as wet-blue . At the end of twentieth century, the brazilian industry discarded about 131 thousand tons of this residue in nature, provoking a great environmental liability. In this paper is presented the analyses of the termophysical properties, thermal and volumetric expansion performance of a composite of vegetable resin of castor oil plant (Ricinus communis) with load of industrial residue of leather "wet-blue", for application as thermal isolation material of warm surfaces. There were considered four percentile levels of residue load in the proportions in mass of 0%, 5%, 10% and 15%, added to the expansible resin of castor oil plant in two configurations: sawed leather and crushed leather in a smaller particle (powder) by grinding in a mill of balls. Twenty-one proof bodies were produced for termophysical properties analysis (three for each configuration) and four proof bodies for rehearsals of thermal acting. Analyses of thermal acting were done in test cameras. The results of the rehearsals were compared to those obtained considering the castor oil plant foam without residue addition. A small reduction of the thermal conductivity of the composite was observed in the proportion of 10% of leather residue in both configurations. Regarding thermal conductivity, calorific capacity and diffusivity, it was verified that the proposed composite showed very close values to the commercial insulating materials (glass wool, rock wool, EPS). It was still demonstrated the technical viability of the use of composite as insulating thermal for systems of low potency. The composite presented larger volumetric expansion with 15% of sawed residue of leather.
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We studied the feasibility of using a system of Solar Water Heating (SAS) with low cost, for three configurations. In configurations I and II have the collector grid absorber composed of six PVC tubes placed in parallel on the tile cement. In configuration II, the PVC tubes were transparent cover made of plastic bottles. Configuration III uses a collector composed of 12 black HDPE pipes, supported on four cement tiles 2.44 m x 0.50 m, two by two overlapping and interspersed with a filling of glass wool, comprising an area exposed to the global radiation incident of 2.44 m2, with the top two tiles painted matte black. In this configuration, the HDPE pipes replace conventional PVC pipes painted black. The total cost of SAS for configuration III, the most economical, was around $ 150.00. For the configurations tested the system of operation was thermosyphon collector. The study showed that the proposed systems have good thermal efficiency, are easy to install and handle and have low cost compared to conventional.
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The use of reflective surfaces functioning as thermal insulator has grown significantly over the years. Reflective thermal insulator are materials that have several characteristics such as low emissivity, low absorptivity and high reflectivity in the infrared spectrum. The use of these materials has grown a lot lately, since it contains several important radioactive properties that minimize the heat loss of thermal systems and cooling systems that are used to block the heat on the roof of buildings. A system made of three surfaces of 316 stainless steel mirror was built to analyze the influence of reflective surfaces as a way to reduce the heat loss and thereby conserve the energy of a thermal system. The system was analyzed both with and without the presence of vacuum, and then compared with a system that contained glass wool between the stainless steel mirror walls, since this isolator is considered resistive and also broadly used around the world in thermal systems. The reflectivity and emissivity of the surfaces used were also measured in this experiment. A type K thermocouple was fixed on the wall of the system to obtain the temperature of the stainless steel mirror surfaces and to analyze the thermal behavior of each configuration used. The results showed an efficiency of 13% when the reflective surfaces were used to minimize the heat loss of the thermal system. However, the system with vacuum had the best outcome, a 60% efficiency. Both of these were compared to the system made of glass wool as a thermal insulator
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The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. The fibers were characterized and made matting (non-woven). The phases of the project were consisted to develop methods and to convert these fibers (booster) blended with polyester resin (matrix) in different proportions (10%, 20% and 30%) at the composite. Were studied fiber characteristics, mechanical properties of the composites, water absorption and scanning electron microscopy. Initially, the fibers were treated with solution of sodium hydroxide of 0.05 mols, and then taken to matting preparing at the textile engineering laboratory - UFRN. The composites were made by compression molding, using an orthophthalic polyester resin as matrix and 1% MEK (methyl ethyl ketone peroxide) as initiator (catalyst). To evaluate the mechanical tests (tensile and flexural) and water absorption were made twelve specimens with dimensions 150x25x3 mm were cut randomly. According to the standard method, tensile tests (ASTM 3039) bending tests (ASTM D790) were performed at the mechanical testing of metals at laboratory UFRN. The results of these tests showed that the composite reinforced with 30% had a better behavior when exposed to tension charge; while on the three points bending test showed that the composite reinforced with 10% had a better behavior. In the water absorption test it was possible to see that the highest absorption happened on the composite reinforced with 30%. In the micrographs, it was possible to see the regions of rupture and behavior of the composite (booster / matrix)