Papers by Keyword: Residue

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Authors: Lei Bo, Xin Yan Zhu
Abstract: The adaptive Kalman filtering algorithm was adopted in the online estimate of navigation state of unmanned aerial vehicle (UAV) as the simplified model often used. At the moment, the alogorithms those usually applied in this territory are not perfect. Analysed the adaptive Kalman filtering based on Maximum-Likelihood Estimation and Sage-Husa Kalman filtering, take advantage the characteristics of residue, choose the estimation windows, a simplified adaptive Kalman filtering algorithm was gived.
Authors: M. Luiza Lopes O. Santos, Antonio Eduardo Martinelli, M.A.F. Melo, D.M.A. Melo
Abstract: One of the major current environmental concerns is the excessive or inefficient consumption of non-renewable natural resources. The construction industry is one of the largest consumers of natural raw materials, playing an important role in the degradation of the environment. Recycling and reusing are concepts that can be effectively applied in the formulation of construction materials, especially mortars. In particular, calcareous quarry can replace, at least to some extent, the cement used in the composition of bricklaying mortars. The objective of this study was to prepare and characterize mortars containing calcareous quarry. The mortars were prepared using Portland CP II F – 32 cement, CH I hydrated lime, river sand and tap water. Different concentrations of residues, ranging from 5 to 30% were used to replace the cement. Mortars with volume ratio of 1:0.5:4.5, commonly used in bricklaying structural masonry, were evaluated. The water to cement ration was set to 1.45. The residue used was fully characterized to determine their specific mass, unitary mass, particle size distribution and morphology, and composition. The mortars were characterized both in their fresh and the results compared to those obtained from a residue-free composition. The results showed that the use of calcareous quarry partially replacing the cement did not significantly affect the performance of the mortars. Compositions containing up to 30% of calcareous quarry can be classified according to NBR 13281 (ABNT, 2005) as bricklaying mortars, and can be used by the construction industry.
Authors: Thierry Conard, Scott List, Martine Claes, Burkhard Beckhoff
Authors: Tércio G. Machado, Uilame Umbelino Gomes, Flanelson M. Monteiro, Samara M. Valcacer, Gilson G. da Silva
Abstract: The scheelite occurs mainly in northeastern Brazil, with highest abundance in the states of Rio Grande do Norte and Paraíba - Scheelite Seridó Province. Mining is considered an activity that provides a high environmental degradation due to the large amount of minerals and waste involved. Most mining companies have no technologies or processes that allow the recycling of mineral waste generated. The aim of this study is to evaluate the influence of different percentages of reject on the mechanical properties of scheelite and aesthetic (staining of the final product after firing) of the clay of the city of Boa Saúde - RN. The raw materials used were characterized by XRD, XRF and particle size analysis. Assay was performed by water absorption, linear retraction and bending tests on three points for the characterization of the final product. The raw materials used were from the city of Currais Novos-RN.
Authors: Ana M.G.D. Mendonça, Alexsandra Cristina Chaves, Gelmires Araújo Neves, Lisiane Navarro de Lima Santana
Abstract: The study of moisture expansion (ME) in ceramic products has been object of research in the past few years, especially in UFCG. The ME is the increase of the dimensions of the ceramic materials by adsorption of water, it occurs slowly and is relatively small, being able to compromise the adherence of the ceramic plates to the subfloor, lead to the cracking of the glaze and conduct to the appearance of cracks in bricks, if the tensions generated by the deformation contained in the pieces exceed the limit resistance of the materials. Aiming to contribute with this research, this study aimed to characterize the alternative ceramic masses from ceramic blocks, seeking to determinate their influence in the development of the moisture expansion phenomenon. Compositions were formulated through the design of simplexes network mixtures technique. The specimens were conformed by uniaxial pressing at 20 MPa, dried in an oven at 110 °C and fired at temperatures of 800°, 900° and 1000 °C. After firing the MEs were determined by boiling and immersion. The results showed that the higher the percentage of granite waste in the formulation, lower the ME.
Authors: Andreas V. Kadavanich, Sang Hoon Shim, Harry M. Meyer, Stephen E. Savas, Edgar Lara-Curzio
Abstract: Photoresist stripping after ion implantation at high dosages (>1E15 atoms/cm2) is the most challenging dry strip process for advanced logic devices. Such high-dose implant stripping (HDIS) frequently leaves residues on the wafers after dry strip, unless fluorine chemistries are employed in the stripping plasma. Silicon loss requirements at sub-45nm nodes generally preclude such aggressive stripping chemistries. Instead, a wet clean is used to remove residues. However, the nature of the residues is not well understood, and are believed to usually contain some of the cross-linked, carbonized organic polymer formed in the implant [1]. In this paper we present chemical and mechanical data on HDIS residues produced from oxidizing and reducing chemistry strip processes.
Authors: Luiz Franscisco Isaias, Luana Spricigo Furlan, Fernando Pelisser, Michael Peterson, Oscar Rubem Klegues Montedo, Agenor de Noni
Abstract: The aim of this work was the obtaining coarse aggregate from red mud (RM) focused on the processing properties. RM and two clays (A and B) were selected from Pará state (Brazil) and characterized by XRD, XRF and HSM. Six compositions were planned by mixture design. RM amount varied from 80 to 100wt%. Compositions were pelletized in a pelletizer disc, resulting test pieces of 4 to 19 mm (diameter). Firing temperatures ranged from 1150 to 1190 oC and holding time from 15 to 90 min. Pelletizing humidity, dry friability, water absorption, and apparent density were determined. Clays A and B presented clay mineral content about 67 and 12 wt%, quartz 25 and 82wt%, respectively. The higher clay mineral contents the smaller dry friability and water absorption. Appropriated clay mineral contents and firing parameters is needed in order to satisfy processing and final properties requirements, being possible to obtain aggregates from pelletizing process.
Authors: Jae Hyun Bae, Jae Mok Jung, Kwon Taek Lim
Abstract: In this work, we studied HF/scCO2 dry etching processes with various co-solvents for the purpose of reducing the residues. The effect of co-solvent on etch rate and selectivity was also investigated.
Authors: Li Chen, Chun Hong Jia
Abstract: This paper investigated the analytical method of degradation and persistence of carbofuran, its metabolite 3-hydroxy carbofuran in peanut seeds, fronds and soils in field trial using gas chromatography mass spectrometry (GC-MS). Carbofuran 3GR formulation (3g a.i./100g) was applied at dosages of 2250 and 3375g ha-1 in furrow at sowing peanut seeds in the fields of Langfang, Hebei province and Jinan, Shandong province, China, respectively. The soil and the plant samples were collected at different intervals and the residues of carbofuran and 3-hydroxy carbofuran were analyzed by GC-MS. The degradation kinetic result showed that the degradation of carbofuran in peanut fronds in Jinan and Langfang can be well predicted with equation: C=1.2839e-0.1733t and C=0.5731e-0.1567t, with a half-life about 4.0 and 4.4 days respectively. For the degradation of carbofuran in soils, the result coincides well with equations: C= 4.2057e-0.2229t, and C= 5.4014e-0.1499t, with half-life of 3.1 and 4.6 days for Jinan and Langfang, respectively. The pH, organic matter and clay content as well as the climatic temperature play an important role in the degradation of carbofuran in soils. 3-hydroxy carbofuran dissipated rapidly both in peanut fronds and soils, it was not detectable 7 days after treatment for all treatment, the concentration of carbofuran and 3-hydroxy carbofuran in peanut seeds at harvest time were lower than either the maximum residue limit in China or the EUs maximum residue limit of 0.1 mg kg1. Based on the data from this investigation, the use of carbofuran in peanut could be considered to be safe.
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