Influence of the thermal treatment of industrial solid residue (Grits) on the mechanical resistance of a latosol for forest engineering roads

Em estudos que envolvem o tratamento de solos com aditivos químicos com fins rodoviários, merecem especial importância aquelas pesquisas orientadas no sentido de descobrir novos meios de torná-los mais econômicos e, ao mesmo tempo, mais resistentes. No presente trabalho, o resíduo sólido industrial Grits, oriundo do processo de fabricação de papel e celulose, foi aplicado a um latossolo denominado ETA, característico da microrregião de Viçosa, Minas Gerais, Brasil, com o intuito de melhorar suas características mecânicas para sua aplicação em pavimentos de estradas florestais. O Grits, após receber tratamento térmico a 200, 300, 400, 500 e 600 ºC, em mufla, foi misturado no teor de 10%, em peso, ao solo anteriormente citado. Parâmetros geotécnicos, característicos dos ensaios de compactação e resistência à compressão simples, foram utilizados para avaliar o efeito do tratamento térmico nas misturas solo+10% Grits. Os resultados indicaram que o Grits tem potencial para estabilização de solos de pavimentos de estradas florestais, sendo o melhor resultado alcançado para o Grits tratado a 600 ºC, pois houve ganhos de resistência mecânica. ____________________________________________________________________________________ ABSTRACTRoad engineering studies involving chemical stabilization of soils deserve special recognition mainly those directed to lowering the costs of forest engineering roads. This work focuses on soil stabilization of a characteristic Latosol from Viçosa, Minas Gerais, Brazil, herein named ETA, using a residue from paper and cellulose industry production, herein called Grits. Grits content of 10% related to soil dry weight was used throughout the study after residue thermal treatment using a furnace at 200, 300, 400, 500 and 600 ºC. Geotechnical standard parameters from compaction and unconfined compression tests were used to evaluate the effect of thermal treatment on the mechanical response of soil-Grits mixtures. Unconfined compression testing data show that Grits is a promising soil stabilizer, mainly after thermal treatment at 600 ºC

Physical and environmental behavior of solid waste in forest road pavements

O objetivo deste estudo foi avaliar os parâmetros físicos de solos da região de Viçosa, Minas Gerais, Brasil, e misturas de rejeitos industriais conhecidos como lama-de-cal e grits. A caracterização foi realizada através dos ensaios de análise granulométrica, análise térmica e microscopia eletrônica de varredura. Foram selecionadas duas amostras de solo residual, ETA (argiloso) e VS (arenoso), as quais foram misturadas com 16, 18, 20, 22 e 24% de lama-de-cal e grits (em peso de matéria seca). As misturas de solo-lama-de-cal e solo-grits apresentaram grande capacidade de retenção de metais pesados, o que impossibilita a sua interação com o sistema hídrico pela possibilidade de contaminação do lençol freático e cursos d.água.The objective of the present study was the assessment of physical parameters of mature and young residual soils from the municipality of Viçosa, Minas Gerais, Brazil, as well as their mixtures with industrial waste known as whitewash mud and grits. Physical characterization was carried out through laboratory tests such as sieve analysis, thermal analysis and scanning microscopy. Two residual soil samples were chosen for this study, ETA (a clayey soil) and VS (a sandy soil), which were stabilized with 16 %, 18 %, 20 %, 22 % e 24 % (referred to dry weight) of residual wastes aforementioned. Data from laboratory testing program supported that mixtures of soil and residual waste had a high heavy metal retention capacity, which might be of concern due to the possibility of contamination of water table and local streams

Effect of crown-to-implant ratio and crown height space on marginal bone stress: a finite element analysis

Crown-to-implant ratio and crown height space, associated with the use of short implants, have been related with marginal bone loss. However, it is unclear which of the two entities would play the most important role on the bone remodelling process. Using a finite element analysis, the present work aims to help clarifying how those two factors contribute for the stress generation at the marginal bone level. A numerical model (reference model), with a crown-to-implant ratio of 4, was double validated and submitted to a numerical calculation. Then, it was modified in two different ways: (a) by decreasing the prosthetic height obtaining crown-to-implant ratios of 3, 2.5 and 2 and (b) by increasing the implants length obtaining a crown-to-implant ratio of 2.08. The new models were also submitted to numerical calculations.Partial financial support provided by FCT, through INEGI, under LAETA, Project UIDB/50022/2020

Intelligent cutting-off of pipes and bars

Traditionally, automatic cutting-off machines, of metallic pipes or bars, use a constant cutting velocity mode. This mode of operation, constant cutting velocity combined with different profiles of materials to be cut, exposes the cutting saw to variable cutting forces. Therefore, the cutting off machine is usually set for the worst expected conditions, otherwise excessive wear of the saw and machine will occur. Further, traditional cutting-off machines require the adjustment of the position of a limit switch in order to automatically detect when the cut of a piece has been completed. The aim of this paper is to study the application of control algorithms to the process of cutting-off metallic pipes or bars, with variable profiles, implemented in an industrial cutting-off machine, commercially available. The presented algorithms concern realtime cutting control and automatic detection of the cutting end. The algorithms are implemented in a low cost Programmable Logic Controller (PLC), allowing its use in industrial applications without significant increase on machine cost. All algorithms were developed having in mind safety issues relative to the operation of the cutting machine in order to prevent catastrophic failure. Also, all process related relevant parameters are monitored on a Personal Computer using OPC (Object Linking and Embedding – for Process Control)

Using the First Principal Component as a Core Inflation Indicator

This paper investigates the consequences of non-stationarity for the principal components analysis and suggests a data transformation that allows obtaining smoother series for the first principal component to be used as a core inflation indicator. The paper also introduces a theoretical model, which allows interpreting core inflation as a common stochastic trend to the year-on-year rates of change of the price indices of the basic CPI items. Finally, it is shown that the first principal component computed in real time meets the evaluation criteria introduced in Marques et al. (2000).

An agent-based approach to group decision simulation using argumentation

Group decision making simulation allows for the creation of virtual group decision scenarios. The use of a group decision simulator enhances user competences in this area, to test different argumentation strategies and to validate “what if” useful real world scenarios. In this paper, it is proposed a multiagent model to simulate group decision making tasks. Agents are designed with emotional properties, reason with incomplete information and use persuasive argumentation to convince the other group elements about the best alternative choice.Fundação para a Ciência e a Tecnologia (FCT) - ArgEmotionAgents Project (POSI / EIA / 56259 / 2004)

A formal approach to argumentation in group decision scenarios

Time and space consuming are disadvantages in group meetings but are easily faced in computer systems. Agent based group decision support systems reduce the loss usually associated to group work, turning more relevant the benefits that emerge from group meetings. Better decisions are taken after negotiation through choice and convincement. In this paper, a formal logic programming based system is proposed to represent agent knowledge and reasoning in order to be used in argumentation for decision group taking, supporting meetings where agents participate and communicate

Schistosoma haematobium and bladder cancer: what lies beneath?

Schistosoma haematobium is a parasitic flatworm that infects millions of people, mostly in the developing world, and is associated with high incidence of bladder cancer although why is not clear. But our group was able to define the mechanistic relationship for the first time between infection of S. haematobium and cancer. We used in vitro models to demonstrate the presence of informative carcinogenesis-associated phenotypes in CHO cells exposed to Sh total antigen, in which we showed increased cell proliferation, decreased apoptosis, up regulation of the anti-apoptotic molecule Bcl-2, down regulation of the tumor suppressor protein p27, and increased cell migration and invasion. We further discuss the molecular and cellular events that might be responsible for schistosomiasis-related bladder cancer

Emotions on agent based simulators for group formation

Time and space consuming are key factors in a meeting, and therefore must be object of consideration in any process of socialization. So, group decision simulation could be a valuable training tool, through which it will be possible to create and test virtual group decision scenarios. In this work we propose a multi-agent simulator of group decision making that models the participant cortex by considering its emotional states and the exchange of arguments among them.Fundação para a Ciência e a Tecnologia (FCT) - ArgEmotionAgents Project (POSI/EIA/56259/2004)

Cell differentiation and morphologic heterogeneity of gastric carcinoma : Insights from the immunocytochemical and molecular study of trefoil peptides and E-cadherin = Diferenciação celular e heterogeneidade morfológica do carcinoma gástrico : Estudo imunocitoquímico e molecular de "trefoil peptides" e da caderina-E

Dissertação de Doutoramento em Biologia Humana apresentada à Faculdade de Medicina da Universidade do Port