Uso de Resíduo Madeireiro Amazônico na Fabricação de Tijolos de Solo-Cimento no Município de Alta Floresta – MT / Timber Residue Use in the Manufacture of Soil-Cement Bricks for Civil Construction in the City of Alta Floresta- MT

Resumo: A discussão sobre edificações sustentáveis vem sendo abordada há décadas por diferentes autores, em geral com foco no consumo energético e na vida útil dos materiais, contudo para atender esses objetivos são necessárias novas tecnologias que promovam mais sustentabilidade. Para tanto, a inclusão de fibras vegetais em compostos de solo-cimento se mostram uma alternativa interessante, e pelo fato do setor industrial madeireiro movimentar a economia local no município de Alta Floresta o resíduo serragem passa a ser um possível agregado nos tijolos ecológicos, uma vez que o armazenamento inadequado deste resíduo pode causar sérios impactos ambientais, portanto, este estudo se propôs a desenvolver um tijolo ecológico fabricado a partir da mistura de solo-cimento e serragem de três espécies florestais da Amazônia, Cambará - Vochysia sp., Cedrinho - Erisma uncinatum Warm., Garapeira. - Apuleia sp, e ainda avaliar a resistência a compressão com intervalos de cura de 7, 14, 21 e 28 dias, com o intuito de verificar a viabilidade do material construtivo. Para a realização do experimento, os tijolos foram fabricados com traço de 1:8:2,5, (cimento: solo: serragem) e a serragem utilizada com dois tratamentos, in natura e tratada por imersão e padronização granulométrica. O material misturado foi compactado em uma prensa hidráulica. Como resultado, os tijolos com serragem apresentaram valores de resistência mecânica de: Cedrinho 1,26Mpa, Cambará 1,70Mpa e Garapeira 1,95Mpa e teores de absorção de umidade de 15,7%, 17,6% e 13,8%, respectivamente.Palavras-chave: Sustentabilidade. Tijolo solo-cimento. Serragem. Abstract: The discussion about sustainable edifications has been addressed in decades by different authors, generally focusing energetic consume and the materials lifespan, however to reach these goals it is necessary new technologies that promote more sustainability. For that the inclusion of vegetal fibers in soil-cements composts present as an interesting alternative, and because the timber industry moves the local economy in the city of Alta Floresta the sawdust residue become a possible aggregate of ecologic bricks since inadequate storage of this material can cause serious environment impacts, therefore this study propose to develop an ecologic brick manufactured by the mix of soil-cement and sawdust of three Amazonian species: Cambará - Vochysia sp., Cedrinho - Erisma uncinatum Warm, Garapeira. - Apuleia sp., and also evaluate the compression resistance in 7, 14, 21, 28 days intervals, aiming to verify the feasibility of the constructive material. To carry out the experiment the bricks were manufacture with the ratio of 1:8:2,5 (cement: soil: sawdust), and the sawdust used was treated twice, in natura, treated by immersion and granulometric standardization. The mixed material was compacted in a hydraulic press. As a result, the sawdust bricks showed resistance values of: Cedrinho 1.26 MPa, Cambará 1.70 MPa and Garapeira 1.95 MPa and humidity absorption percentage of 15.7%, 17.6%, and 13.8% % respectively.Keywords: Sustainably, Ecologic Brick, Sawdust

RECYCLE GLASS WASTE AS A REPLACEMENT OF FINE AGGREGATE IN CONCRETE MIX STANDARD COMPARISON

Recycling is one way that is used to minimize the amount of waste that exists. Recycling is also a process to reduce the use of new raw materials, reduce energy use, reduce pollution, land degradation and greenhouse gas emissions. Materials that can be recycled consist of waste of glass, plastic, paper, metal, textiles and electronic goods. Glass has characteristics suitable as concrete aggregates, considering that glass is a material that does not absorb water. In addition, glass has high abrasion resistance. Meanwhile, the waste glass flux lowers the temperature to the temperature at which the formers will melt. Stabilizers in glass waste are made of calcium carbonate, which makes the glass waste solid and water-resistant. This glass waste is recycled by mixing it into the concrete mix. The recycling method is done by pounding the glass and putting it into the concrete mix stage. The purpose of mixing the glass waste is expected to increase the compressive strength of concrete. The use of glass waste as a mixed material affects the compressive strength of the concrete. The concrete with the most inferior to highest compressive strength is 4% variation concrete, 2% variation concrete, and traditional concrete. Optimal percentage addition of glass waste impacts on maximum concrete compressive strength is 2% mixture variation which obtained 11,88 Mpa & 11,32 Mpa.

Prediction And Verification of Wafer Surface Morphology in Ultrasonic Vibration Assisted Wire Saw (UAWS) Slicing Single Crystal Silicon Based On Mixed Material Removal Mode

Monocrystalline silicon is one of the most important semiconductor materials, widely used in chip manufacturing, solar panels. Slicing is the first step in making chips and the surface quality of silicon wafers directly affects the quality of later processing and accounts for a large proportion in the chip manufacturing cost. Ultrasonic vibration assisted wire saw (UAWS) is an effective sawing process for cutting hard and brittle materials such as monocrystalline Si, which can significantly improve the surface quality of silicon wafers. In order to further study the formation mechanism of the surface morphology of single crystal silicon sliced by UAWS, a new model for prediction of wafer surface morphology in UAWS slicing single crystal silicon based on mixed material removal mode is presented and verified in this paper. Firstly, the surface model of diamond wire saw tool is established by equal probability method. Then according to the equation of transverse vibration dynamics about the wire saw with ultrasonic excitation, the trajectory equation of arbitrary abrasive particles on the surface of wire saw is derived and analyzed. Thirdly, a new model for prediction of the wafer surface morphology based on mixed material removal mode is presented, which can be used to predict the wafer surface morphology of single crystal silicon sliced by UAWS. Finally, the prediction model is verified by UAWS slicing experiment, and the effects of slicing parameters such as wire saw speed, feed speed and workpiece rotate speed on the surface quality of silicon wafer were studied. It shows that the predicted wafer surface morphology and the experimental wafer surface morphology are similar in some characteristics, and the average error between the experimental and the theoretical values of the wafer surface roughness is 11.9%, which verifies the validity of the prediction model.

Construction and Evaluation of a Vertical Motorized Feed Mixer

In order to reduce the overall cost of poultry production by small scale farmers, a motorized feed mixer was modified, fabricated and evaluated. The mixer consists of an outer drum, an inner mixing chamber and an auger. All these components were vertically oriented for mixing operation. There was a hopper located at the base of the mixer for loading the materials and a chute for the discharging of mixed products. It was modified to work through a central rotating auger fixed on a shaft that carries a pulley of diameter 185 mm. The rotational motion was transmitted from a motor through a V-belt to the pulley shaft. A 5-0 hp electric motor with 1440 rpm was used to drive the machine. Mixing was achieved as the auger conveyed the feed materials from the bottom to the top, in a continuous rotational motion. The mixer was evaluated using a whole corn kernel (WCK) at 15.35 % (d.b) and small pieces of coloured paper (CP) of 5x5 mm² as tracers in ground maize as base materials. The auger pitch was reduced from 90.0 mm to 85.0 mm to increase the number of pitches from 10 to 12. This modification increased the throughput capacity of the mixer from 50.0 kg to 70.0 kg. The mixed material was delivered through the delivery chute after mixing. Mixing time values evaluated were 2.0, 4.0, 6.0, 8.0 and 10.0 mins. The test results showed that maximum mixing occurred at 6.0 mins for coloured paper and 8.0 mins for whole kernel corn.

Determining the Composition of a Mixed Material with Synthetic Data

Determining the composition of a mixed material is an open problem that has attracted the interest of researchers in many fields. In our recent work, we proposed a novel approach to determine the composition of a mixed material using convolutional neural networks (CNNs). In machine learning, a model “learns” a specific task for which it is designed through data. Hence, obtaining a dataset of mixed materials is required to develop CNNs for the task of estimating the composition. However, the proposed method instead creates the synthetic data of mixed materials generated from using only images of pure materials present in those mixtures. Thus, it eliminates the prohibitive cost and tedious process of collecting images of mixed materials. The motivation for this study is to provide mathematical details of the proposed approach in addition to extensive experiments and analyses. We examine the approach on two datasets to demonstrate the ease of extending the proposed approach to any mixtures. We perform experiments to demonstrate that the proposed approach can accurately determine the presence of the materials, and sufficiently estimate the precise composition of a mixed material. Moreover, we provide analyses to strengthen the validation and benefits of the proposed approach.

Kekerasan Produk Metalurgi Serbuk Berbahan Limbah Aluminium dengan Metode Kompaksi Bertahap

The product resulting from the powder metallurgy process has advantages in terms of mechanical properties and physical properties. Material engineering by mixing several types of metal powders is very possible to do. The composition of this powder metallurgical process material is a mixture of aluminum powder (80%), copper powder (15%) and silicon carbide powder (5%) by weight then compacted with a compaction load gradually, starting with a load of 3 tons, holding for 3 minutes, followed by a load of 3 tons. 4 tons were held for 3 minutes and the last 5 tons were held for 3 minutes by pre sintering 1250C. Sintering in the kitchen with temperature variations of 4500C, 5000C and 5500C and sintering time for 60 minutes. Tests carried out on the specimens were hardness tests using the Rockwell (HRF) method. The results showed that the hardness of a single material has a hardness of around 35 HRF. The average hardness of the mixed material at a sintering temperature of 4500C is 80 HRF. The hardness of the mixed material at a sintering temperature of 5000C on average is 74 HRF. Meanwhile, the hardness of the mixed material at a sintering temperature of 5500C averaged 52 HRF. It can be concluded that the application of heat at the time of compaction and the selection of the sintering temperature greatly affect the hardness of the product resulting from the powder metallurgy process.

RESEARCH OF THE POSSIBILITY OF INCREASING THE QUALITY OF PREPARATION OF DRY MIXTURES IN A HORIZONTAL VANE MIXER

Paddle mixers with horizontal shafts are common at building materials enterprises for the preparation of concretes, mortars, dry mortars. A new design of a horizontal paddle mixer with rod elements located in front of the working surfaces of the blades, changing the trajectories of material particles, increasing their mobility, which leads to an increase in the degree of homogeneity of the mixed material, is considered. The aim of the study was to assess the influence of rod elements on the quality of preparation of a cement-sand mixture, to establish patterns of influence on it by the design and technological parameters of a two-shaft paddle mixer and to determine the areas of their rational values. The following tasks have been solved. A bench installation of a two-shaft horizontal paddle mixer with rod elements has been developed, on which experimental studies have been carried out on the preparation of dry cement-sand mixtures. For the criterion characterizing the quality of the mixture, the ultimate compressive strength of the prism specimens made from it is adopted. Regression equations are obtained that adequately describe the compressive strength of prism samples from the design and technological parameters of the mixer: the angle of the blades, the distance from the working surfaces of the blades to the rod elements, the rotational speed of the blade shafts, and their analysis is performed. The analysis of the change in the ultimate compressive strength of the prism specimens from the parameters under study is carried out, the rational ranges of their values are determined. It was found that a mixer with rod elements allows to obtain a dry cement-sand mixture, products from which have a higher compressive strength. During the work, the method of mathematical planning of experiments was used. As a result of the study, an assessment of the influence of rod elements on the quality of preparation of a cement-sand mixture was carried out, the regularities of the influence on it of the design and technological parameters of a two-shaft paddle mixer and the area of their rational values were established.

Retenção ou "adesividade" do acréscimo de misturas de ZnO/Eugenol ao material já endurecido, nas moldagens de próteses totais

ln the techniques for obtaining impressions of edentulous mouths with zinc oxide - eugenol impression materials it is common procedure to add newly mixed material to the already hardened impression in order to improve or "correct" the impression. It was our purpose to find out about the retentive or "adhesive" qualities of the above mentioned "additions" to the hardened material. To obtain this information weused a tensile strenght test in which the "added" material remained in the geometrical center of the test samples. As a comparison, test samples were also used, without added material. Five of the most widely used zinc-oxide/eugenol impression materials in Brazil were utilized throughout the experiments. The results, presented through Graphs and Tables, were statistically analysed. The addition of newly mixed material to already hardened material caused a reduction in tensile strenght values in all live impression pastes. This reduction, however, was not significant in paste "C"; it was significant (.05) in pasle "A” and highly significant (.01) in pastes,"B", "D"and "E”.

DESIGN AND PARAMETER OPTIMIZATION OF WATER-RETAINING MOULDING DEVICE FOR STRAW AND COW DUNG MIXED MATERIALS

A hydraulic horizontal water-retaining moulding device for mixed materials was designed and optimized. The effect of compression process parameters of the mixture of straw and cow dung on the effect of water retention moulding was analysed through experiment. The suitable value range and critical value of process parameters were obtained. The main power and structural parameters of the hydraulic system in the mixture compression unit were designed and calculated. Appropriate hydraulic and control components were selected. A test prototype of the hydraulic horizontal mixed material compressor machine was manufactured. Through the method of combination experiment and response surface optimization, the optimal combination of working parameters of the hydraulic horizontal water-retaining moulding device was obtained and verified. The dimensional stability of small-scale compost blocks made by the compressor could reach 84.71% under the condition of 250 mm/min for the compression speed, 55 kg for the feed amount and 200 s for the holding time.