Geopolímeros são uma nova classe de ligantes cimentícios obtidos a partir da reação química entre um aluminossilicato amorfo (precursor) e um ativador alcalino. Esses materiais tem se tornado uma alternativa interessante no desenvolvimento de novos cimentos devido sua reduzida emissão de CO2, bem como pelo potencial de valorização de resíduos. Além disso, apresentam algumas vantagens técnicas como elevada resistência mecânica inicial, baixa permeabilidade e estabilidade química em certas condições de uso. Como precursores utiliza-se normalmente aluminossilicatos provenientes de resíduos como cinza volante, escória de alto forno ou argilas calcinadas como o metacaulim. Como ativadores, os mais tradicionais são os hidróxidos e silicatos solúveis. A pesquisa de novas fontes de silicato provenientes de resíduos industriais gerados em grande volume pode facilitar a adoção desses materiais na indústria da construção. Com isso, esse trabalho avaliou a produção de diferentes ligantes geopoliméricos a partir da utilização como precursores de lodo de caulim calcinado (LCC), e cinza pesada (CP). Da mesma forma foi desenvolvido um ativador alcalino alternativo baseado na dissolução da sílica amorfa presente na cinza de casca de arroz (CCA). Os precursores foram ativados individualmente, bem como em combinações binárias, utilizando silicato de sódio comercial, silicato de sódio alternativo e hidróxido de sódio como ativadores. Os geopolímeros foram sintetizadas a partir de relações molares e critérios de síntese utilizados pela literatura. Os produtos de reação foram avaliados perante algumas técnicas de caracterização como calorimetria isotérmica, difração de raios-X, espectroscopia de infravermelho com transformada de Fourier e análise termogravimétrica entre 1 e 90 dias de cura. Complementarmente a resistência à compressão foi avaliada até 90 dias de cura. Os resultados das análises micro e macroestruturais mostram que é viável utilizar ambos resíduos avaliados como precursores para geopolímeros, sendo possível obter resistências à compressão potencial de até 80 MPa. O conteúdo de silicato solúvel apresenta uma função importante perante a cinética de reações, possibilitanto um material mecanicamente mais resistente. O uso do ativador alcalino alternativo é uma alternativa viável para a produção de um material ambientalmente mais amigável, proporcionando características mecânicas e microestruturais similares aos geopolímeros produzidos com ativadores tradicionais. / Geopolymers are a new class of binder obtained through a chemical reaction between an amorphous aluminosilicate (precursor) and an alkaline activator. This material is a good alternative to the development of more environmental friendly binders, as well as the opportunity to valorize industrial wastes. These materials also show some technical advantages, including high compressive strength at early times of curing, low permeability and higher chemical stability under certain condition of exposure. As precursors, aluminosilicates from industrial wastes such as fly ash (FA), granulated blast furnace slag (GBFS) and/or calcined clays such as metakaolin (MK) are typically used. As activators, the most commonly used are hydroxides and soluble silicates. Therefore, the search of novel aluminosilicates sources from industrial wastes locally available in large volumes could facilitate the adoption of geopolymers by the construction industry. This study assessed the production of different geopolymer binders using as precursors calcined kaolin sludge (CKS) from the Brazilian mining industry and a bottom ash (BA) generated during coal combustion. An alternative alkali activator produced by the dissolution of rice husk ash (RHA) was also evaluated, in order to optimize the environmental benefits of these materials. The precursors were activated individually and also blended using sodium hydroxide, commercial sodium silicate and alternative sodium silicate as activators. The geopolymers were produced based on literature review. The reaction products formed upon alkali activation were evaluated using different characterization techniques, including isothermal calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, thermogravimetric analysis coupled with mass spectrometry. Complementary, the compressive strength of the geopolymer pastes produced was evaluated up to 90 days of curing. The micro and macro structural characterization results show that these waste are suitable precursors to produce geopolymer binders, with compressive strengths as high as 80 MPa after 7 days of curing. The content of soluble silicates plays an important role in the kinetic of geopolymerization, favoring a high compressive strength development. The use of an alternative alkali activator based it is a feasible alternative to produce more environmental friendly geopolymers with similar mechanical performance to that of geopolymers produced with traditional soluble silicates based on commercial sodium silicate solutions.

A tentativa de modificar algumas propriedades dos solos é antiga. Alguns autores fazem considerações a tentativas ocorridas a três mil anos atrás. Com o crescimento populacional e o desenvolvimento de novos sistemas de produção ocorridos após a Revolução Industrial no século XVIII, houve uma intensa ocupação territorial exigindo obras de infra-estrutura e obras complementares, tornando cada vez mais comum o melhoramento de solos. Uma técnica in situ passível de aplicação para melhorar as propriedades mecânicas dos solos é a técnica de eletrocinética associada à injeção de soluções químicas. Esta é caracterizada pela aplicação de um baixo gradiente elétrico através de eletrodos num meio poroso inundado com soluções químicas. Nesta pesquisa, foram realizados ensaios associando as soluções de cloreto de cálcio com água carbonatada, cloreto de cálcio com bicarbonato de sódio além de cloreto de cálcio com silicato de sódio. Para verificação da ocorrência da cimentação entre as partículas de areia, após a saturação do corpo de prova com as devidas soluções, mas anterior à aplicação da diferença de potencial elétrico ao solo, foram realizados três ensaios de prospecção com um Miniature Cone, desenvolvido nesta pesquisa. Esses foram comparados a outros três ensaios que foram realizados após o período de aplicação da técnica. Todas as associações resultaram em regiões cimentadas não homogêneas, sendo que os melhores resultados foram obtidos com a associação das soluções de cloreto de cálcio e silicato de sódio. A aplicação da técnica de eletrocinética associada a injeções de soluções químicas mostrou se complexa e difícil de predizer devido ao número de variáveis que podem modificar o seu resultado final. / The attempt to change some soil properties of the soil is not new. Some authors describes attempts occurred three thousand years ago. With population growth and the new production systems development that occurred after the Industrial Revolution in the eighteenth century, there was an intense territorial occupation requiring infrastructure works and complementary works, becoming the soils improvement usual. One of the in situ soil improvement techniques is the eletrokinetics associated with injection of chemical solutions. This technique is characterized by the application of a low electrical gradient through electrodes in a porous media flooded with chemical solutions. In this study, tests were carried out associating the solutions of calcium chloride with soda water, calcium chloride with sodium bicarbonate, and calcium chloride with sodium silicate. To verify the occurrence of the cementation among the sand particles, after the samples flooded with the appropriate solutions, but prior to the application of electric potential difference in the soil, three exploration tests were performed with a Miniature Cone, developed in this study. These tests were compared to other three tests that were carried out after the application of the technique. All associations resulted in not homogeneous cemented regions, and the best results were obtained with the combination of the solutions of calcium chloride and sodium silicate. The application of the eletrokinetics technique associated with injections of chemical solutions is proved to be complex and difficult to be predicted due to the number of variables that can change its final result.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-08-18T21:15:21Z No. of bitstreams: 2 Dissertação - Débora Macedo Paronetto Viana - 2015.pdf: 1160036 bytes, checksum: 74179969a46784eda015c0776c564c67 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-19T13:06:52Z (GMT) No. of bitstreams: 2 Dissertação - Débora Macedo Paronetto Viana - 2015.pdf: 1160036 bytes, checksum: 74179969a46784eda015c0776c564c67 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-19T13:06:52Z (GMT). No. of bitstreams: 2 Dissertação - Débora Macedo Paronetto Viana - 2015.pdf: 1160036 bytes, checksum: 74179969a46784eda015c0776c564c67 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-06-24 / The use of silicon shows promising results in productivity of crops. However, its effectiveness on minimizing the effects of water stress on tomato crop is incipient and should be studied. The objective of this study was to evaluate sodium silicate doses through foliar application on tomato (Solanum lycopersicum) and to evaluate the negative effects of water stress under greenhouse conditions. The quality (length, fruit diameter and weight, shell thickness and number of fruits per plant) of tomato was quantified, along with fruit productivity parameters. Plants of the salad group were subjected to four watering rounds (3, 6, 9, 12 days), and three concentrations of sodium silicate (Na2SiO3) (0.0% Si L-1, 0.2% Si L-1 and 0.4% Si L-1) through foliar application. The values stipulated for irrigation intervals correspond to levels ranging from a sufficient water supply to plants to water deficit. The irrigation management was carried out with the aid of an evaporimeter, or mini-tank class A. The experimental design was a randomized block design with a factorial 3x4 (sodium silicate doses x irrigation intervals), totaling 12 treatments with four replications each. In general, the irrigation interval alone influenced more the productivity parameters than the fruit quality parameters. As the plants were growing older, it was detected more significant effect of silicon on parameters evaluated. / O uso de silício apresenta resultados promissores em função de produtividade das culturas, entretanto, a sua eficácia ou não, em minimizar os efeitos do estresse hídrico na cultura do tomate são incipientes e devem ser estudadas. O objetivo deste trabalho foi avaliar doses de silicato de sódio via aplicação foliar em plantas de tomate Solanum lycopersicum e avaliar os efeitos negativos do estresse hídrico sob condições de cultivo protegido. A qualidade (comprimento, diâmetro e peso médio dos frutos, espessura da casca e número de frutos planta-1) do tomate foram quantificadas, além de parâmetros de produtividade dos frutos submetidos aos tratamentos. Plantas de tomate grupo salada foram submetidas a quatro turnos de rega (3, 6, 9, 12 dias), e três concentrações de silicato de sódio (Na2SiO3) (0,0 % Si L-1, 0,2 % Si L-1 e 0,4 % Si L-1) via aplicação foliar. Os valores estipulados de turno de rega compreenderam níveis variando desde a suficiente oferta de água à planta até o déficit hídrico. O manejo da irrigação foi realizado com o auxílio de um evaporimetro, ou mini tanque classe A. O delineamento experimental utilizado foi em blocos casualizados, em esquema fatorial 3x4 (doses de silicato de sódio x turno de rega), totalizando doze tratamentos com quatro repetições. De maneira geral, o turno de rega considerando-o de forma isolada influenciou mais em parâmetros de produção do que nos de qualidade do fruto. A partir do momento em que as plantas de tomate foram tornando-se mais velhas ocorreu maior significância do fator silício nos parâmetros avaliados.

The design, construction and optimization of a low power-high temperature heated ceramic sensor to detect leaking of halogen gases in refrigeration systems are presented. The manufacturing process was done with microelectronic assembly and the Low Temperature Cofire Ceramic (LTCC) technique. Four basic sensor materials were fabricated and tested: Li2SiO3, Na2SiO3, K2SiO3, and CaSiO3. The evaluation of the sensor material, sensor size, operating temperature, bias voltage, electrodes size, firing temperature, gas flow, and sensor life was done. All sensors responded to the gas showing stability and reproducibility. Before exposing the sensor to the gas, the sensor was modeled like a resistor in series and the calculations obtained were in agreement with the experimental values. The sensor response to the gas was divided in surface diffusion and bulk diffusion; both were analyzed showing agreement between the calculations and the experimental values. The sensor with 51.5%CaSiO3 + 48.5%Li2SiO3 shows the best results, including a stable current and response to the gas.

No description available.

Embankment dams is the most common type of dams in operation inSweden today. Due to the nature of embankment dams, seepage throughthem will always occur. If the seepage velocity exceeds a critical velocity,internal erosion is initiated, which could lead to damage in form of pipingand sinkholes. To treat this problem, remedial grouting has beenperformed involving a combination of conventional grouts, i.e. cement andcement-bentonite as well as sodium silicate, which is a chemical grout thatalso known as water glass. Regarding the sodium silicate grout, there isconcern about the long-term permanence.The aim of this thesis has been to study the potential performance ofsodium silicate grouted in embankment dams. The first part of this thesisis a literature review of the general behavior of sodium silicate as a grout,its degradation processes and the factors that could induce degradation.The second part suggests monitoring methods to control and evaluate theperformance of the treated dam and the grout if degradation has occurred.Findings from literature generally indicates a high risk of instability andlow permanence of sodium silicate when grouted in an embankment dam.This type of grout will undergo degradation mainly in two forms: syneresisinduced shrinkage and leaching due to grout erosion or dissolution. As thedegradation has developed, an increase in permeability of the repaireddam core is a potential consequence.How the potential degradation of sodium silicate will affect the treateddams is suggested to be observed by monitoring the permeability of thegrouted core. Applicable monitoring methods for this purpose aremeasurements of pore pressure and temperature using piezometers. Thesecond direct method of monitoring a changed dam behavior is suggestedto be leakage analysis, in order to detect potentially increased leakagebecause of the grout degradation. An indirect way to investigate the damperformance is suggested to be monitoring of the grout state. Measurementof ion concentration of sodium and silicon respectively in leakage waterusing selective-ion electrodes will reveal any increase in ion concentrationdue to the potential grout dissolution or leaching.

Yes / Geopolymers have been recognised as a viable replacement to ordinary Portland cement (OPC), providing a cleaner solution since it can significantly reduce greenhouse gas emissions as well as accomplishing effective waste recycling. Construction and demolition waste (CDW) has been recently identified as raw materials for geopolymers due to its availability and high contents of silica and alumina. This paper aimed at reviewing the current state-of-the-art on the geopolymer paste, mortar, and concrete production and their properties, with special attention paid to geopolymers incorporating CDWs. The review covers brief assessment of using CDWs in concrete, the mix design of geopolymer mixtures in addition to identification of the main factors influencing the performance of geopolymer containing CDW. The most recent data related to the mechanical and durability properties of CDW-based geopolymers are presented, while the cost and environmental impacts of using recycled materials in producing geopolymer concretes are also discussed. Geopolymer concretes have a vast range of possible applications, however, there are still several barriers facing commercialisation of geopolymers in construction industry. The review indicated that it is possible to produce geopolymer concretes from CDW-based materials with properties comparable to OPC-based ones; however, the selection of proper material composition should be carefully considered, especially under normal curing conditions.

The deposition of amorphous silica from aqueous solution on to rutile particles has been studied with the aim of elucidating the nature of the silica-titania interactions occurring and of following the progressive build up of the silica coating. The coating process, which involves the addition of an aqueous sodium silicate solution to an aqueous dispersion of titanium dioxide, has been investigated by performing a series of controlled preparations and using the technique of microelectrophoresis. Prepared silica-coated rutile samples ranging from partial to full silica coatings have been characterized using transmission electron microscopy, microelectrophoresis and nitrogen, argon and water sorption. Nitrogen and argon adsorption isotherms have been analysed using the equation of Brunauer, Emmett and Teller (BET). Differential energies of adsorption of nitrogen and argon have been determined calorimetrically. Water sorption isotherms have been analysed using the BET equation and the Frenkel - Halsey - Hill (FHH) equation. It has been shown that uniform silica coatings can be produced if adsorption of monomeric silica is followed by polymerization of silica at the solid/liquid interface. Surface cations on rutile may be hydroxylated or co-ordinately bound to water molecules and it appears that monomeric silica adsorbs preferentially by replacing ligand water molecules. Rutile particles with silica coatings thicker than approximately 2.5nm exhibit characteristics typical of silica and not of the base rutile. Silica coatings deposited at pH 10 contain narrow channels which are accessible to water molecules but not to nitrogen or argon. Neutralization to pH 7 reduces the volume in the coating accessible to water molecules.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Brown rot is the main diseases of peaches, with pre and postharvest losses. Control it is difficult because the fungus infect fruit and remain latent until conditions are favorable to its manifestation. Therefore, to understand the role of latent infection of the disease incidence and find strategies to minimize losses, with low environmental impact, is essential for sustainable crop management. This thesis consists of four papers that resulted from work with the following objectives: to study the relationship between latent infection and the occurrence of postharvest brown rot; to evaluate the effect of preharvest fungicide application on the Monilinia fructicola control during storage and marketing of peaches; to investigate the pre and postharvest applications of silicon on the brown rot control in peach. They were used peaches of Eldorado and Pepita cultivars, in field experiments involving preharvest spraying of fungicides and pre and postharvest applications of silicon and experiments in refrigerated storage conditions at -0.5 ° C. Iprodione, tebuconazole and difenoconazole are effective in brown rot control in the field conditions, while in postharvest, the incidence was controlled in 96.2% with iminoctadine. These products decreased the incidence of injuries resulting from latent infections. There is a high correlation between the presences of latent infections in preharvest with the incidence of the disease in postharvest, with most of the damage after cold storage resulting from the latent infections of Monilinia fructicola. Foliar application of 6 g L-1 sodium silicate or sodium metasilicate is effective in controlling the disease without causing phytotoxicity to the plants. Six sodium silicate applications had the same effect as six fungicides applications to brown rot control in peaches Eldorado . Postharvest sodium metasilicate application, in 6 g L-1, reduced the diseases incidence but caused fruit skin darkening. Physical defense mechanisms of the plants are affected by silicon application, because it increased the element content in the leaves and fruits, and increased skin texture. However, the effect of silicon on the biochemical defense mechanisms may involve the synthesis of polyphenols, because in the one year of search we found a higher content of these compounds in fruit treated with silicon. In general, products based on silicon, applied alone or intercalated with fungicides, control the disease in pre and postharvest, allowing a decrease in fungicide use and production cost. / A podridão parda do pessegueiro é a doença de maior importância para a cultura, com danos em pré e pós-colheita. O controle é dificultado devido à habilidade do fungo de infectar os frutos e permanecer latente até que as condições tonarem-se favoráveis à sua manifestação. Portanto, compreender o papel da infecção latente na incidência da doença, bem como encontrar estratégias que minimizem as perdas, com baixo impacto ambiental, é fundamental para o manejo sustentável da cultura. Esta tese é composta por quatro artigos científicos que resultaram de trabalhos com os seguintes objetivos: estudar a relação da infecção latente com a ocorrência da podridão parda em pós-colheita; avaliar o efeito da aplicação pré-colheita de fungicidas no controle do fungo Monilinia fructicola durante o armazenamento e comercialização de pêssegos; investigar o potencial do silício em pré e pós-colheita no controle da podridão parda do pessegueiro. Foram utilizados pêssegos das cultivares Eldorado e Pepita em experimentos a campo envolvendo pulverizações pré-colheita de fungicidas e aplicações pré e pós-colheita de produtos à base de silício e experimentos em condições de armazenamento refrigerado a 0,5 ºC. Os fungicidas iprodione, tebuconazole e difenoconazole foram eficazes no controle da podridão parda a campo, enquanto que em pós-colheita, a incidência foi controlada em 96,2% com iminoctadina. Esses produtos também reduziram a incidência de lesões decorrentes de infecções latentes. Há uma alta correlação entre a presença de infecções latentes em pré-colheita com a incidência da doença em pós-colheita, sendo a maior parte das lesões após o armazenamento refrigerado decorrentes das infecções latentes do fungo Monilinia fructicola. Aplicação foliar de 6 g L-1 de metassilicato de sódio ou de silicato de sódio foram eficazes no controle da doença sem causar fitotoxidez às plantas. Seis aplicações de silicato de sódio tiveram o mesmo efeito que seis aplicações de fungicidas no controle da podridão parda em pêssegos cv. Eldorado. A aplicação de metassilicato de sódio em pós-colheita, na dose de 6 g L-1, reduziu a incidência da doença, mas causou escurecimento da epiderme dos frutos. Os mecanismos físicos de defesa das plantas são afetados pelo Si, pois houve aumento do conteúdo do elemento nas folhas e frutos e aumento da textura da epiderme, entretanto, o efeito do silício sobre os mecanismos bioquímicos de defesa pode envolver a síntese de polifenóis, pois em um dos anos da pesquisa verificou-se maior conteúdo destes compostos em frutos tratados com silício. Em geral, produtos à base de silício, aplicados isoladamente ou intercalados com fungicidas, controlam a doença em pré e pós-colheita proporcionando redução no uso de fungicidas e no custo de produção.

A study was conducted to investigate and quantify the effects of corrosion inhibitors on metal release within a pilot distribution system while varying the source water. The pilot distribution system consisted of pre-existing facilities from Taylor et al (2005). Iron, copper, and lead release data were collected during four separate phases of operation. Each phase was characterized by the particular blend ratios used during the study. A blended source water represented a water that had been derived from a consistent proportion of three different source waters. These source waters included (1) surface water treated through enhanced coagulation/sedimentation/filtration, (2) conventionally treated groundwater, and (3) finished surface water treated using reverse osmosis membranes. The corrosion inhibitors used during the study were blended orthophosphate (BOP), orthophosphate (OP), zinc orthophosphate (ZOP), and sodium silicate (Si). This document was intended to cite the findings from the study associated with corrosion treatment using various doses of sodium silicate. The doses were maintained to 3, 6, and 12 mg/L as SiO2 above the blend-dependent background silica concentration. Sources of iron release within the pilot distribution system consisted of, in the following order of entry, (1) lined cast iron, (2) un-lined cast iron, and (3) galvanized steel. Iron release data from these materials was not collected for each individual iron source. Instead, iron release data represented the measurement of iron upon exposure to the pilot distribution system in general. There was little evidence to suggest that iron release was affected by sodium silicate. Statistical modeling of iron release suggested that iron release could be described by the water quality parameters of alkalinity, chlorides, and pH. The R2 statistic implied that the model could account for only 36% of the total variation within the iron release data set (i.e. R2 = 0.36). The model implies that increases in alkalinity and pH would be expected to decrease iron release on average, while an increase in chlorides would increase iron release. The surface composition of cast iron and galvanized steel coupons were analyzed using X-ray photoelectron spectroscopy (XPS). The surface analysis located binding energies consistent with Fe2O3, Fe3O4, and FeOOH for both cast iron and galvanized steel. Elemental scans detected the presence of silicon as amorphous silica; however, there was no significant difference between scans of coupons treated with sodium silicate and coupons simply exposed to the blended source water. The predominant form of zinc found on the galvanized steel coupons was ZnO. Thermodynamic modeling of the galvanized steel system suggested that zinc release was more appropriately described by Zn5(CO3)2(OH)6. The analysis of the copper release data set suggested that treatment with sodium silicate decreased copper release during the study. On average the low, medium, and high doses decreased copper release, when compared to the original blend source water prior to sodium silicate addition, by approximately 20%, 30%, and 50%, respectively. Statistical modeling found that alkalinity, chlorides, pH, and sodium silicate dose were significant variables (R2 = 0.68). The coefficients of the model implied that increases in pH and sodium silicate dose decreased copper release, while increases in alkalinity and chlorides increased copper release. XPS for copper coupons suggested that the scale composition consisted of Cu2O, CuO, and Cu(OH)2 for both the coupons treated with sodium silicate and those exposed to the blended source water. Analysis of the silicon elemental scan detected amorphous silica on 3/5 copper coupons exposed to sodium silicate. Silicon was not detected on any of the 8 control coupons. This suggested that sodium silicate inhibitor varied the surface composition of the copper scale. The XPS results seemed to be validated by the visual differences of the copper coupons exposed to sodium silicate. Copper coupons treated with sodium silicate developed a blue-green scale, while control coupons were reddish-brown. Thermodynamic modeling was unsuccessful in identifying a controlling solid that consisted of a silicate-based cupric solid. Lead release was generally decreased when treated with sodium silicate. Many of the observations were recorded below the detection limit (1 ppb as Pb) of the instrument used to measure the lead concentration of the samples during the study. The frequency of observations below the detection limit tended to increase as the dose of sodium silicate increased. An accurate quantification of the effect of sodium silicate was complicated by the observations recorded below detection limit. If the lead concentration of a sample was below detection limit, then the observation was recorded as 1 ppb. Statistical modeling suggested that temperature, alkalinity, chlorides, pH, and sodium silicate dose were important variables associated with lead release (R2 = 0.60). The exponents of the non-linear model implied that an increase in temperature, alkalinity, and chlorides increased lead release, while an increase in pH and sodium silicate dose were associated with a decrease in lead release. XPS surface characterization of lead coupons indicated the presence of PbO, PbO2, PbCO3, and Pb3(OH)2(CO3)2. XPS also found evidence of silicate scale formation. Thermodynamic modeling did not support the possibility of a silicate-based lead controlling solid. A solubility model assuming Pb3(OH)2(CO3)2 as the controlling solid was used to evaluate lead release data from samples in which lead coupons were incubated for long stagnation times. This thermodynamic model seemed to similarly describe the lead release of samples treated with sodium silicate and samples exposed to the blended source water. The pH of each sample was similar, thus sodium silicate, rather than the corresponding increase in pH, would appear to be responsible if a difference had been observed. During the overall study, the effects of BOP, OP, ZOP, and Si corrosion inhibitors were described by empirical models. Statistically, the model represented the expected value, or mean average, function. If these models are to be used to predict a dose for copper release, then the relationship between the expected value function and the 90th percentile must be approximated. The USEPA Lead and Copper Rule (LCR) regulates total copper release at an action level of 1.3 mg/L. This action level represents a 90th percentile rather than a mean average. Evaluation of the complete copper release data set suggested that the standard deviation was proportional to the mean average of a particular treatment. This relationship was estimated using a linear model. It was found that most of the copper data sub-sets (represented by a given phase, inhibitor, and dose) could be described by a normal distribution. The information obtained from the standard deviation analysis and the normality assumption validated the use of a z-score to relate the empirical models to the estimated 90th percentile observations. Since an analysis of the normality and variance (essentially contains the same information as the standard deviation) are required to assess the assumptions associated with an ANOVA, an ANOVA was performed to directly compare the effects of the inhibitors and corresponding doses. The findings suggested that phosphate-based inhibitors were consistently more effective than sodium silicate when comparing the same treatment levels (i.e. doses). Among the phosphate-based inhibitors, the effectiveness of each respective treatment level was inconsistent (i.e. there was no clear indication that any one phosphate-based inhibitor was more effective than the other). As the doses increased for each inhibitor, the results generally suggested that there was a corresponding tendency for copper release to decrease.