Plaster reinforcement with fibers by mineral wool obtained from the recycle of construction and demolition waste

The use of mineral wool is becoming more widespread due to increased acoustic and thermal demands of Spanish Technical Building Code. This increase affects both in rehabilitation and new construction projects. Therefore, waste generation of this type of insulating material is having more importance. The main objective of this research is to study the possibility of recycling fiber obtained from mineral wool of the C&DW as an alternative material to chopped glass fibers that are currently used as reinforcing elements in the prefabricated plaster. To achieve this objective, series are made of plaster E-35 additived with rock wool residue and glass wool residue at different rates of addition. These series are repeated by changing the additive by E fiberglass (length of 25mm) to make a comparative analysis with respect to the series additived with mineral wool waste. All the series are subjected to the test to determine Shore C surface hardness and mechanical testing to determine the compressive and flexural strength. From the results it can be concluded that: with rock wool residue, increases Shore C hardness up to 15% with respect to the glass fiber and 9% with respect to the glass wool, with a percentage of addition 2%. With rock wool residue, weight is decreased by 5% with respect to the glass fiber and 4% with respect to the glass wool waste, with an addition percentage of 4%. For an addition rate of 4%, results in the flexural strength test with fiberglass are 85% higher than those obtained with glass wool residue. However, for a percentage of 1% addition, the results obtained with glass wool residue are 35% higher than those obtained with fiberglass. For an addition rate of 3% results in the compressive strength test with fiberglass are 54% lower than those obtained with rock wool waste and 70% lower than those obtained with glass wool waste. Comparing the two mineral wools, it can be concluded that up to 3% of the addition, the glass wool series results obtained are 10% higher than those additived with rock wool. However, higher percentages of addition show that the results obtained with rock wool are 35% higher than those obtained with glass wool. The general conclusion is that the series additived with mineral wool from C&DW show better results in tests than the ones used nowadays as plaster reinforcement.

Microbial quality of hemp (Cannabis sativa L.) and flax (Linum usitatissimum L.) from plants to thermal insulation

Flax and hemp have traditionally been used mainly for textiles, but recently interest has also been focused on non-textile applications. Microbial quality throughout the whole processing chain of bast fibres has not previously been studied. This study concentrates on the microbial quality and possible microbial risks in the production chain of hemp and flax fibres and fibrous thermal insulations. In order to be able to utilize hemp and flax fibres, the bast fibres must be separated from the rest of the plant. Non-cellulosic components can be removed with various pretreatment processes, which are associated with a certain risk of microbial contamination. In this study enzymatic retting and steam explosion (STEX) were examined as pretreatment processes. On the basis of the results obtained in this study, the microbial contents on stalks of both plants studied increased at the end of the growing season and during the winter. However, by processing and mechanical separation it is possible to produce fibres containing less moulds and bacteria than the whole stem. Enzymatic treatment encouraged the growth of moulds in fibres. Steam explosion reduced the amount of moulds in fibres. Dry thermal treatment used in this study did not markedly reduce the amount of microbes. In this project an emission measurement chamber was developed which was suitable for measurements of emissions from both mat type and loose fill type insulations, and capable of interdisciplinary sampling. In this study, the highest amounts of fungal emissions were in the range of 10^3 10^5 cfu/m^3 from the flax and hemp insulations at 90% RH of air. The fungal emissions from stone wool, glass wool and recycled paper insulations were below 10^2 cfu/m^3 even at 90% RH. Equally low values were obtained from bast fibrous materials in lower humidities (at 30% and 80% RH of air). After drying of moulded insulations at 30% RH, the amounts of emitted moulds were in all cases higher compared to the emissions at 90% RH before drying. The most common fungi in bast fibres were Penicillium and Rhizopus. The widest variety of different fungi was in the untreated hemp and linseed fibres and in the commercial loose-fill flax insulation. Penicillium, Rhizopus and Paecilomyces were the most tolerant to steam explosion. According to the literature, the most common fungi in building materials and indoor air are Penicillium, Aspergillus and Cladosporium, which were all found in some of the bast fibre materials in this study. As organic materials, hemp and flax fibres contain high levels of nutrients for microbial growth. The amount of microbes can be controlled and somewhat decreased by the processing methods presented.

The rate and mechanism of the partial oxidation of acetaldehyde by PPM concentrations of nitrogen dioxide

The thermal reaction between nitrogen dioxide and acetaldehyde in the gas phase was investigated at room temperature and atmospheric pressure. The initial rate of disappearance of nitrogen dioxide was 1.00 ± 0.03 order with respect to nitrogen dioxide and 1.00 ± 0.07 order with respect to acetaldehyde. An initial second order rate constant of (8.596 ± 0.189) x 10^-3 1.mole^-1 sec^-1 was obtained at 22.0 ± 0.1 °C and a total pressure of one atmosphere. The activation energy of the reaction was 12,900 cal/mole in the temperature range between 22°C and 122°C.

The products of the reaction were nitric oxide, carbon dioxide, methyl nitrite, nitromethane and a trace amount of trans-dimeric nitrosomethane. The addition of nitric oxide increased the rate of formation of nitromethane and decreased the rate of formation of methyl nitrite. There were no measurable surface effects due to the addition of glass wool or glass beads to the reactor.

Reactants and products were analyzed by gas chromatography. A mechanism was proposed incorporating the principal features of the reaction.

Millora de la qualitat espermàtica de dosis seminals de mascles reproductors Piétrain per filtració en diverses reïnes

En aquest treball s'ha dissenyat un mètode ràpid i fiable de tinció amb fluorocroms per a l'anàlisi de la integritat i viabilitat espermàtiques a partir del marcatge de la beina mitocondrial amb MitoTracker®Green FM, de l'acrosoma amb la lectina Trypsin inhibitor from Soybean (SBTI) conjugada amb el fluorocrom Alexa Fluor®488 específic per la proacrosina i del nucli amb els fluorocroms bis-benzimida (específic per a cèl·lules viables) i iodur de propidi (específic per a cèl·lules no viables). També s'ha determinat l'efecte de la filtració de dosis seminals de mascles astentoteratonecrospèrmics en columnes de Sephadex neutre i de dosis de mascles amb baixa qualitat espermàtica per filtració en columnes de Sephadex iònic, llana de vidre i glass beads sobre la qualitat espermàtica dels diferents grups de mascles analitzats. Els resultats obtinguts han mostrat que diversos paràmetres de qualitat espermàtica milloren després de la filtració en les diferents reïnes segons la patologia que presentin.

Efeito da adição de microfibras de lã de vidro na tenacidade à ruptura de pastas de cimento para poços de petróleo

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

Fibras de sisal (Agave sisalana) como isolante térmico de tubulações

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

Compósito de poliuretano de mamona e vermiculita para isolação térmica

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

Desenvolvimento de material compósito a base de raspa de pneu e látex para isolamento térmico

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

Desenvolvimento de compósito de pu de mamona com carga de resíduo de couro para isolação térmica

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.

Projeto, construção e análise de eficiência térmica de um sistema de aquecimento solar de água de baixo custo

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.

Análise da influência de superfícies refletivas nas perdas de calor de sistema térmicos

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

Behavior of Leishmania major metacyclic promastigotes during the course of infection and immune response development in resistant versus susceptible hosts

Pouco se conhece sobre os epítopos derivados de promastigotas metacíclicos de Leishmania que são importantes para a regulação ou destruição do parasita, como alvos de ação imunológica no hospedeiro vertebrado. Neste estudo, nós investigamos um método alternativo para obter promastigotas metacíclicos de Leishmania major, pela avaliação do curso da infecção e reação de hipersensibilidade do tipo retardado (HTR) em hospedeiros resistentes e susceptíveis. Promastigotas não-infectantes (procíclicos) de L. major, recentemente isolados de amastigotas, foram selecionados pela adesão a colunas de lã de vidro negativamente carregadas, enquanto que promastigotas metacíclicos não se aderem à coluna e podem ser recuperados com facilidade. Condições ótimas de cromatografia foram validadas por análise estatística. O rendimento médio de parasitas obtidos após separação em colunas de lã de vidro e a viabilidade dos promastigotas foram estimados por microscopia óptica. Os promastigotas metacíclicos tiveram um rendimento médio de 43,5% a 57,5%. Camundongos BALB/c (susceptíveis) e camundongos C57BL/6 (resistentes) apresentaram padrões distintos de lesões cutâneas, os primeiros com lesões mais agressivas, induzidas por promastigotas metacíclicos. As respostas à reação de HTR foram maiores nos grupos de camundongos C57BL/6, submetidos à infecção com promastigotas metacíclicos. Estes resultados indicam que o novo método poderia ser integrado aos protocolos existentes para estudar a metaciclogênese de parasitas do gênero Leishmania in vivo.

Rapid determination of desorption efficiency, and analysis of solvent mixtures for occupational exposure studies

An analytical procedure has been developed for simultaneous determination of solvent mixture vapors to enable evaluation of occupational exposure. To determine the desorption efficiency the volatile components of the solvent mixtures were generated from a glass tube filled with glass wool. This device is easy to prepare and use. These vapors were then collected in activated charcoal tubes and analyzed by capillary gas chromatography. The method was tested with a mixture of 22 solvents, including aliphatic and aromatic hydrocarbons, alcohols, ethers, esters, and ketones, oil at low concentrations. All the components were defected. When a 99: 1 mixture of carbon disulfide-dimethylformamide was used for desorption the efficiency was > 75% for most of the solvents.

Study on the use of oxidant scrubbers for elimination of interferences due to nitrogen dioxide in analysis of atmospheric dimethylsulfide

Neste trabalho foi avaliado o desempenho de filtros para dióxido de nitrogênio, buscando evitar perdas durante a amostragem de sulfetos orgânicos, provocadas por oxidantes atmosféricos. Diferentes compostos e misturas foram usadas para recobrir superfícies sólidas empregadas na preparação destes filtros. Um sistema automatizado de análise em fluxo foi utilizado para comparar a eficiência de retenção de dióxido de nitrogênio pelos filtros. Entre os materiais testados na preparação dos filtros, as melhores escolhas foram papel ou lã de vidro impregnados com a mistura de sulfato de ferro (II), ácido sulfúrico e ácido pirogalico e ainda os filtros feitos de papel impregnados com trietanolamina. Os resultados obtidos em laboratório com mistura de gás padrão de dimetilsulfeto e experimentos em campo confirmaram a qualidade dos filtros e indicaram que eles podem ser utilizados para evitar a oxidação de sulfetos orgânicos durante a sua amostragem.

Utilização de membranas de borracha natural com nanopartículas de prata como métodos de separação de parasitas de Leishmania braziliensis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)