Memoria para optar al título profesional de: Ingeniero Agrónomo Mención: Fitotecnia / La producción hortícola nacional abarca una gran diversidad de cultivos, dentro de los cuales la lechuga destaca por sus 5.425 ha (ODEPA, 2013), como también por su consumo masivo. El presente estudio intenta evaluar la factibilidad de utilizar Espuma Agrícola Ultrafoam® Rooting Media en reemplazo de los sustrato convencionales empleados tanto en horticultura convencional como en hidroponía, como son la turba, perlita expandida y lana de roca, con el objetivo de comprobar una mayor precocidad en la obtención de plantines con aptitudes óptimas para trasplante y también conferir una mayor resistencia al shock postrasplante. Se produjeron plantines en un invernadero utilizando bandejas plásticas termoformadas con 162 alvéolos de 16 cm 3 de volumen por alvéolo. Como sustrato se utilizó turba rubia, lana de roca y perlita expandida, además de la espuma agrícola. Cuando se obtuvo las condiciones óptimas para el trasplante, los plantines fueron llevados a una parcela experimental para evaluar su comportamiento hasta 20 días postrasplante. Los resultados mostraron que en la etapa de almácigo los plantines obtenidos en espuma agrícola no fueron más precoces que los producidos en los demás sustratos, siendo los producidos en la mezcla turba-perlita los que mostraron mayor precocidad y superiores estadísticamente en altura, área foliar, color y materia fresca, no encontrándose diferencia estadísticamente significativa en el parámetro de materia seca. El comportamiento postrasplante de los distintos tratamientos, mostró que la mezcla turbaperlita fue estadísticamente superior solo en el parámetro de materia seca, en tanto que en las demás evaluaciones, no se encontró diferencia entre los tratamientos. / The national horticultural production includes a great variety of crops. Lettuce is one of the most important crops for Chile because of the planted area 5.425 ha according to the Agrarian Policy and Research Office (ODEPA for its acronym in Spanish), and its massive consumption. This investigation aims to assess the feasibility of using agricultural foam Ultrafoam® Rooting Media in order to replace conventional substrates, like peat moss, expanded perlite and rockwool, used in both conventional horticulture and hydroponics with the objective of proving two facts: that seedlings can be obtained earlier in time with optimal capability to be transplanted and that this product can give them more resistance after being transplanted. Seedlings were grown in a greenhouse using thermoformed plastic trays with 162 cells of 16 cm 3 each. In addition to agricultural foam, peat moss, rockwool and expanded perlite were used as substrates. When optimal conditions for transplant were found, the seedlings were taken to an experimental plot to evaluate their evolution for 20 days after being transplanted. The results showed that the seedlings obtained in agricultural foam grew slower than seedlings obtained in the other substrates during the nursery period. The seedlings in which the mixture of peat moss and perlite was used grew faster and were statistically superior in relation to height, foliar area, color and fresh matter criteria and no significant differences were found in relation to dry matter criterion. The behavior of seedlings after being transplanted showed that the mixture of peat moss and perlite was statistically superior just in the dry matter criterion, while in other evaluations differences were not found.

Memoria para optar al título profesional de: Ingeniero Agrónomo / Se evaluó el comportamiento de dos cultivares de sandía (Citrullus lanatus (Thumb.) Mat. & Nak.) desarrollados en sustratos inertes durante el período de almácigo y 20 días después de trasplante a un sistema hidropónico NFT-modificado, con el fin de evaluar el estrés postrasplante. Se utilizaron los cultivares Yellow Doll y Santa Amelia sobre 100% lana de roca Agrolan®, 100% perlita expandida A6 y una mezcla de ambos en partes iguales. Con el fin de medir la duración de las etapas de desarrollo de los almácigos de sandía desde emergencia hasta el estado de 2ª-3ª hoja verdadera (momento de trasplante) se realizó un seguimiento a los días grado (DG) acumulados. Al momento del trasplante se evaluó: materia seca y fresca, altura y área foliar. Luego de 20 días de establecidos los plantines en el sistema hidropónico, además de las variables mencionadas se evaluaron el número de hojas y el porcentaje de establecimiento de plantas. A excepción de la altura al momento del trasplante, los tratamientos no presentaron diferencias significativas para ninguno de los factores en estudio. Aquellos plantines que se desarrollaron sobre perlita expandida pura necesitaron acumular una menor cantidad de DG para alcanzar cada uno de los estados fenológicos, situación opuesta a lo observado con los plantines desarrollados sobre lana de roca. Sin embargo, al evaluar las variables de crecimiento no se detectaron diferencias significativas entre los sustratos. Respecto de los cultivares en estado de 2ª-3ª hoja verdadera, ´Santa Amelia´ solo en el parámetro materia fresca presentó resultados superiores a ´Yellow Doll´, situación que se mantuvo 20 días después del trasplante. Para las otras variables en estudio no se observaron diferencias. De esta forma, independiente del sustrato en que se desarrollaron los plantines de ambos cultivares, se logró un 100% de establecimiento en el sistema NFT-modificado, sin verse afectado el crecimiento de las plantas por las características intrínsecas de los sustratos. / The effect of two watermelon cultivars (Citrullus lanatus (Thumb.) Mat. & Nak.) developed in inert substrates was evaluated during the nursery growth and 20 days after transplant to a NFT-modified hydroponic system to assess the postransplant stress. ´Yellow Doll´ and ´Santa Amelia´ cultivars were evaluated. The substrates used were granular rockwool (Agrolan®), expanded perlite A6 and a mixture of both substrates in equal part. To measure the duration of the seedling development stage, from emergency until 2nd to 3rd true leaf (transplant stage) the accumulated degree-days were followed through the process. At transplant stage aerial fresh and dry matter, plant height and leaf area were evaluated. After 20 days of establishment in an hydroponic system, the total number of leaves and number of lost plants (establishment %) were also evaluated. With the exception of plant height at transplant stage, no significant differences were observed between treatments due to the studied factors. Seedling growing only in perlite need to accumulate less degree-days to reach the phenological stages than seedlings growing in granular rockwool. However, no significant differences were obtained between the substrate with the other growth measurements. At 2nd - 3rd true leaf stage the cultivars showed significant effect on fresh matter, ´Santa Amelia´ seedlings was significantly higher than ´Yellow Doll´ seedlings, results that were maintained 20 days after transplant. The other variables on this research did not show significant differences. According to the results, independent of the seedling bed substrate, both cultivars had 100% establishment in the NFT-modified hydroponic system, without affecting the plant growth due to the intrinsic characteristics of the substrates. Key words: Citrullus lanatus, ´Yellow Doll´, ´Santa Amelia´, rockwool, perlite .

Memoria para optar al título profesional de Ingeniero Agrónomo Mención Fitotecnia / El sustrato o medio de cultivo es uno de los factores de mayor relevancia en la producción de plantines de hortalizas, básicamente porque es el encargado de proveer el soporte, la aireación, el agua, y en algunos casos la nutrición del sistema radical de la planta. En los últimos años, ha crecido el interés por utilizar sustratos alternativos a los usados hasta hoy, en donde el humus de lombriz se presenta como una clara opción. El presente ensayo se desarrolló con el objetivo de evaluar el efecto de fórmulas de sustratos a base de humus de lombriz, en la calidad de plantines de lechuga Lactuca sativa L. cv. Winterhaven y repollo Brassica oleracea var capitata L. cv. Savoy Ace. Se evaluaron cinco mezclas de sustratos, las cuales contenían humus de lombriz, turba y perlita, más un testigo (70% turba y 30% perlita). Al mismo tiempo estas mezclas de sustratos se caracterizaron física, química y biológicamente. El diseño experimental fue de bloques completos aleatorizados con seis tratamientos y cinco repeticiones para cada especie. Para ambas especies se evaluó el desarrollo de plantines desde emergencia hasta 3-4 hojas verdaderas, además de mediciones al momento del transplante y luego en campo al cabo de 21 días. Producto del seguimiento que se hizo a cada especie, se determinó que el humus de lombriz otorga cierta precocidad en la producción al estado de 3-4 hojas verdaderas, sobretodo en repollo. Asimismo, para ambas especies, al momento del transplante se observó un mayor crecimiento de los plantines producidos en la mezcla que contenía un 70% de humus de lombriz, siendo esto más evidente para repollo. En cuanto a las mediciones realizadas en campo 21 días luego del transplante, se constató que para ambas especies el tratamiento de mejor comportamiento correspondió al que contenía un 56% de humus de lombriz. Por lo tanto, se puede concluir que el humus de lombriz como componente de sustratos tiene efecto positivo sobre el crecimiento y desarrollo de plantines de repollo y lechuga, lo cual también es evidente en campo 21 días después del transplante. / The substrate is one of the most relevant aspects in vegetables seedling production, basically because it is responsible to provide support, air, water, and in some cases nutrients to the plant root system. In recent years, the interest to use alternative substrates has grown, and earthworm humus is presented like a clear choice. The present study was developed with the objective to evaluate the effect of different substrates formulas based on earthworm humus, in lettuce (Lactuca sativa L. cv. Winterhaven) and cabbage (Brassica oleracea var capitata L. cv. Savoy Ace) seedlings. Five substrates mixtures were evaluated, which contained earthworm humus, peat, perlite and a control (70% peat and 30% perlite). At the same time, the substrates mixtures were characterized by physical, chemical and biological analysis. For each species, a randomized complete block design with six treatments and five replicates was used. Seedling development from emergency to 3-4 true leaves, in addition to measurements at the transplant moment and 21 days after transplant were measured for each species. As a result of monitoring each species, it was determined that the earthworm humus at 3-4 true leaves give certain precocity in the production, moreover in cabbage. Also, for both species, at transplant moment, it was observed a major seedling growth in the 70% earthworm humus mix, becoming more evident in cabbage. Regarding the measurement at 21 days after transplant, both species verified that the treatment with the best behavior was the 56% earthworm humus substrate. Therefore, it can be conclude that earthworm humus like substrate component have a positive effect over seedling growth and development, which was also evident in field at 21 days after transplant.

Memoria para optar al título profesional de Ingeniero Agrónomo Mención Fitotecnia / Se evaluó un sustrato usado ampliamente en la producción de plantines en Chile (70% turba + 30% perlita) enriquecido con distintos bioestimulantes aplicados de manera individual, previo a la siembra, con el objeto de analizar el efecto en el crecimiento, desarrollo y calidad de plantines de lechuga y tomate. Los ensayos se realizaron en la plantinera Eco- Plantas Ltda. ubicada en la localidad de Malloco, región Metropolitana, durante la producción primaveral del año 2009. El estudio se realizó en bandejas alveoladas y bajo condiciones de invernadero no climatizado. El ensayo de cada especie estuvo constituido por un diseño en bloques completos al azar con 7 tratamientos (correspondientes a los seis bioestimulantes + el tratamiento testigo, sin aplicación) y 5 repeticiones. Al sustrato base utilizado como tratamiento testigo (sin incorporación de bioestimulante) se le realizó una caracterización física, química y un análisis de fitotoxicidad, mientras que a los otros 6 tratamientos se les realizaron sólo las dos últimas evaluaciones. Se realizó un seguimiento del desarrollo vegetativo de los plantines desde la emergencia hasta el estado de 3ª hoja verdadera. En este estado fenológico se realizaron mediciones de crecimiento correspondientes a diámetro del tallo, altura de planta, área foliar, número de hojas, volumen de raíces, además de peso seco radical, peso seco y fresco de la parte aérea, número de hojas, índice de concentración de clorofila, superficie de contacto de raíz con el sustrato y número de ápices de raíz. Los resultados mostraron que Aminocat® aplicado a una concentración de 5 mL/L de agua utilizada para mojar el sustrato previo a la siembra, produjo un aumento del peso seco aéreo y radical en los plantines de tomate, además de un aumento del área foliar y diámetro del tallo de los mismos. Ninguno de los bioestimulantes comerciales utilizados mejoró los parámetros de crecimiento medidos en los plantines de lechuga. / In order to evaluate the effect on growth, development and seedling quality of lettuce and tomato seedlings, a widely used substrate for seedling production in Chile (70% peat + 30% perlite) enriched whit different biostimulants individually applied and before sowing were evaluated. The study was conduced in “Eco-Plantas Ltda.” nursery, located in Malloco County, Metropolitana region, during the 2009 spring production. The study was performed in speedlings under unheated greenhouse conditions. The trials for each specie consisted in a randomized complete block design with 7 treatments (for six biostimulants + control treatment without application) and 5 repetitions. The substrate used as control (without addition of biostimulant) was analyzed with both a physical and a chemical characterization and also with a phytotoxicity analysis, while in the other six treatments only the last two were performed. The seedlings were monitored for their vegetative development, from emergency until 3rd true leaves. At this stage stem diameter, plant height, leaf area, leaf number, root volume, as well as root dry weight, dry weight and fresh shoot, leaf number, chlorophyll concentration rate, root surface contact with the substrate and number of root tips were measured. The results showed that Aminocat ® applied at a concentration of 5 mL / L of water used to moisten the substrate before sowing, increase the shoot and root dry weight in tomato seedlings, and increase leaf area and stem diameter thereof. None of the used commercial biostimulants improved the growth parameters measured in lettuce seedlings.

O objetivo do presente trabalho, consistiu na obtenção de ferro fundidos nodulares, a serem utilizados na fabricação de eixos, com as seguintes características mecânicas após os tratamentos térmicos adequados: limites de resistência à tração e escoamento mínimos de 700 N/mm2 e 450 N/mm2 respectivamente, alongamento mínimo de 5% e dureza entre 235 à 285 HB. A microestrutura mais adequada à obtenção das características mecânicas desejadas deveria consistir de cementita esferoidizada numa matriz ferrítica, a ser obtida com o tratamento de recozimento ou revenimento de microestruturas previamente perlíticas ou martensíticas, respectivamente. No caso do tratamento de recozimento, as estruturas iniciais consistiram de perlita grossa mais ferrita, presentes no material no estado bruto de fusão, ou, de perlita fina mais ferrita, do material normalizado. Todos os tratamentos térmicos utilizados, dependendo do tempo de tratamento, permitiram a obtenção de cementita esferoidizada. O material normalizado e recozido durante 2 horas a 700ºC, possibilitou a obtenção das propriedades mecânicas desejadas: limites de resistência à tração e de escoamento de 827 N/mm2 e 547 N/mm2 respectivamente, alongamento de 7% e dureza de 277 HB, valores estes, dentro dos limites desejados no presente trabalho. No caso do material temperado e revenido a 700ºC durante 0,5 hora, obteve-se limites de escoamento de 542 N/mm2, alongamento de 6% e dureza de 246 HB. O tratamento de recozimento realizado durante 48 horas, produziu microestrutura quase totalmente ferrítica, com pequenas áreas de agregados de carbonetos. O restante do carbono migrou para os nódulos de grafita secundária ao redor dos mesmos. / The purpose of the present work, consisted in obtaining ductile casting iron, that will be used in the shaft production, with de following mechanical properties after the appropriated heat treatments: ultimate tensile strength and yield strength values of 700 N/mm2 and 450 N/mm2 minimum respectively, elongation of 5% minimum and hardness value from 235 to 285 HB. The microstructure more adequated to obtaining the desired mechanical characteristics should consist of spheroidized cementite in a ferritic matrix, to be obtained with the annealing or tempering treatments of microstructures previously pearlitic or martensitic respectively. In the case of the annealing treatment, the initial structures consisted of thick pearlite plus ferrite, wich were in the material in the ascast state, or fine pearlite plus ferrite, of the normalized material. All the used heat treatment, depending on the time of treatment, allowed the obtainment of spheroidized cementite. The material normalized and annealed for 2 hours at 700°C made possible the obtaining of the desired mechanical properties: ultimate tensile strength and yield strength value of 827 N/mm2 and 547 N/mm2 respectively, elongation of 7% and hardness values of 277 HB, values these, in acordance with the aims initially proposed in the present work. In the case of the material quenched and tempered at 700°C for 0,5 hour, it was obtained yield strength values of 542 N/mm2, elongation of 6% and hardness value of 246 HB. The annealing treatment made during 48 hours, produced a microstructure almost totally ferritic, with small areas of aggregated carbides. The remaining of the carbon migrated to the graphite nodules producing secondary graphite around them.

Made available in DSpace on 2014-12-17T15:41:54Z (GMT). No. of bitstreams: 1 ElisamaVS_DISSERT.pdf: 3256609 bytes, checksum: 7bb56ee7f0f5f70ae8afd8e24e21825f (MD5) Previous issue date: 2011-07-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work, chitosan was used as a coating of pure perlite in order to increase the accessibility of the groups OH- e NH2+the adsorptionof ions Mn2+ e Zn2+.The characterization results of the expanded perlite classified as microporous and whose surface area 3,176 m2 g-1after the change resulted in 4,664 m2g-1.From the thermogravimetry(TG) it was found that the percentage of coating was34,3%.The infrared analysis can prove the presence of groups Si-OH, Si-O e Al-O-Siresulting from the perlite and C=O, NH2and OH characterization of chitosan. The experiments on experiments on the adsorption of Mn and Zn were performed in the concentration range of10 a 50 mgL-1and the adsorption capacity inpH 5,8 e 5,2 was 19,49 and 23,09 mgg-1to 25 oC,respectively.The adsorption data were best fitted to Langmuir adsorption model to Langmuir adsorption model for both metalionsisindicative of monolayer adsorption. The kinetics of adsorption were calculated from the equation of Lagergren fitting the model pseudo-second-order for all initial concentrations, suggesting that adsorption of ions Mn2+ and Zn2+ follows the kinetics of pseudo-second-order and whose constant Speedk2(g/mg.min) are 0,105 e 3,98 and capacity and maximum removal qe 4,326 e 3,348,respectively.In this study we used a square wave voltammetry cathodic stripping voltammetry to quantify the adsorbed ions, and the working electrode glassy carbon, reference electrode silver / silver chloride and a platinum auxiliary electrode. The attainment of the peaks corresponding to ions Mn2+ and Zn2+ was evaluated in and electrochemical cell with a capacity of 30 mL using a buffer system (Na2HPO4/NaH2PO4)at pH 4 and was adjusted with solutionsH3PO4 0,1molL-1and NaOH 0,1 molL-1and addition of the analyte has been a cathodic peak in- 0,873 Vand detection limit of2,55x10-6molL-1para Zn.The dough used for obtaining the adsorption isotherm was 150 mg and reached in 120 min time of equilibrium for both metal ions.The maximum adsorption for 120 min with Mn concentration 20 mgL-1 and Zn 10 mgL-1,was91, 09 e 94, 34%, respectively / Nesse trabalho a quitosana foi utilizada como revestimento da perlita expandida pura com o objetivo de aumentar a acessibilidade dos grupos OH- e NH2+ na adsor??o dos ?ons Mn2+ e Zn2+. A perlita expandida foi classificada como microporoso com uma ?rea superficial de 3,176m2 g-1 e ap?s modifica??o resultou em 4,664m2 g-1. A partir da Termogravimetria (TG) verificou-se que o percentual de revestimento foi de 37,5%. A an?lise de infravermelho comprovou a presen?a dos grupos Si-OH, Si-O e Al-O-Si decorrentes da perlita e C=O, NH2 e OH caracter?sticos da quitosana. Os experimentos na adsor??o de Mn2+ e Zn2+ foram realizados no intervalo de concentra??o de 10 a 50 mg L-1 e acapacidade de adsor??o em pH 5,2 e 5,8 foi de 23,09 e 19,49 mg g-1 a 25 oC, respectivamente. Os dados de adsor??o se ajustaram melhor ao modelo de adsor??o de Langmuir para ambos os c?tions met?licos sendo indicativo de adsor??o f?sica em monocamada.As constantes de velocidade de adsor??o foram calculadas a partir da equa??o Lagergren se ajustando ao modelo de pseudo-segunda-ordem para todas as concentra??es iniciais, sugerindo que a adsor??o dos ?ons Mn2+ e Zn2+ segue a cin?tica de pseudo-segunda-ordem e cujas constantes de velocidade k2(g/mg.min) s?o 0,105 e 3,98 e capacidade m?xima de remo??o qe 4,326 e 3,348 mg g-1, respectivamente. Utilizou-se a voltametria de onda quadrada de redissolu??o cat?dica para a quantifica??o dos ?ons adsorvidos, com o eletrodo de trabalho de carbono v?treo, eletrodo de refer?ncia prata/cloreto de prata e um eletrodo auxiliar de platina. A obten??o dos picos correspondente aos ?ons Mn2+ e Zn2+ foi avaliado em uma c?lula eletroqu?mica com capacidade para 30 mL utilizando um sistema tamp?o (Na2HPO4/NaH2PO4) cuja concentra??o 0,1 mol L-1em pH 4, sendo ajustado com solu??es H3PO4 0,1 mol L-1e NaOH 0,1 mol L-1e adi??o do analito, tendo verificado um pico cat?dico em 0,873 V com limite de detec??o de Mn 7,76x10-7 mol L-1 e um pico an?dico de -1,1 V e limite de detec??o de 2,55x10-6mol L-1 para Zn2+.A massa utilizada para a obten??o das isotermas de adsor??o foi de 150 mg, tendo atingido o tempo de equil?brio de 120 min para ambos ?ons met?licos. A m?xima adsor??o em 120 min para Mn2+ com concentra??o de 20 mg L-1 e Zn 10 mg L-1, foi de 91,09 e 94,34% ,respectivamente

Made available in DSpace on 2014-12-17T15:42:15Z (GMT). No. of bitstreams: 1 LoildeDB_TESE.pdf: 2292456 bytes, checksum: 7268473c8f078f403990f633d690589e (MD5) Previous issue date: 2012-10-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The contamination by metal ions has been occurring for decades through the introduction of liquid effluent not treated, mainly from industrial activities, rivers and lakes, affecting water quality. For that the effluent can be disposed in water bodies, environmental standards require that they be adequately addressed, so that the concentration of metals does not exceed the limits of standard conditions of release in the receptor. Several methods for wastewater treatment have been reported in the literature, but many of them are high cost and low efficiency. The adsorption process has been used as effective for removal of metal ions. This paper presents studies to evaluate the potential of perlite as an adsorbent for removing metals in model solution. Perlite, in its natural form (NP) and expanded (EP), was characterized by X-ray fluorescence, X-ray diffraction, surface area analysis using nitrogen adsorption (BET method), scanning electron microscopy and Fourier transform infrared spectroscopy. The physical characteristic and chemical composition of the material presented were appropriate for the study of adsorption. Adsorption experiments by the method of finite bath for model solutions of metal ions Cr3+, Cu2+, Mn2+ and Ni2+ were carried out in order to study the effect of pH, mass of the adsorbent and the contact time on removal of ions in solution. The results showed that perlite has good adsorption capacity. The NP has higher adsorption capacity (mg g-1) than the EP. According to the values of the constant of Langmuir qm (mg g-1), the maximum capacity of the monolayer was obtained and in terms of proportion of mass, we found the following order experimental adsorption: Cr3+ (2.194 mg g- 1) > Ni2+ (0.585 mg g-1) > Mn2+ (0.515 mg g-1) > Cu2+ (0.513 mg g-1) and Cr3+ (1.934 mg g-1)> Ni2+ (0.514 mg g-1) > Cu2+ (0.421 mg g-1) > Mn2+ (0.364 mg g-1) on the NP and EP, respectively. The experimental data were best fitted the Langmuir model compared to Freundlich for Cu2+, Mn2+ and Ni2+. However, for the Cr3+, both models fit the experimental data / A contamina??o por ?ons met?licos vem ocorrendo h? d?cadas atrav?s do lan?amento de efluentes l?quidos n?o tratados, principalmente de atividades industriais, nos rios e lagos, comprometendo a qualidade da ?gua. Para que os efluentes possam ser descartados em corpos d'?gua, as normas ambientais exigem que os mesmos sejam adequadamente tratados, de modo que a concentra??o dos metais n?o ultrapasse os limites de condi??es padr?es de lan?amento no corpo receptor. V?rios m?todos para tratamento de efluentes t?m sido apresentados na literatura, por?m muitos deles s?o de alto custo e baixa efici?ncia. O processo de adsor??o vem sendo utilizado como eficaz para remo??o de ?ons met?licos. Neste trabalho s?o apresentados estudos para avaliar a potencialidade da perlita como adsorvente na remo??o de metais em solu??o modelo. A perlita, na sua forma natural (PN) e expandida (PE), foi caracterizada por fluoresc?ncia de raios X, difra??o de raios X, an?lise da ?rea superficial usando adsor??o f?sica de nitrog?nio (m?todo BET), microscopia eletr?nica de varredura (MEV) e espectroscopia de infravermelho com transformada de Fourier (FTIR). As caracter?sticas f?sicas e a composi??o qu?mica apresentadas pelo material foram adequadas para o estudo de adsor??o. Ensaios de adsor??o pelo m?todo de banho finito para solu??es modelo dos ?ons met?licos Cr3+, Cu2+, Mn2+ e Ni2+ foram realizados, com intuito de estudar o efeito do pH, da massa do adsorvente e do tempo de contato na remo??o de ?ons em solu??o. Os resultados demonstraram que a perlita apresenta boa capacidade de adsor??o. A PN apresenta maior capacidade de adsor??o (mg g-1) do que a PE. De acordo com os valores da constante de Langmuir, qm (mg g-1), a capacidade m?xima da monocamada foi obtida e em termos de propor??o de massa, encontrou-se a seguinte ordem experimental de adsor??o: Cr3+ (2,384 mg g-1) > Ni2+ (0,585 mg g-1) > Mn2+ (0,515 mg g-1) > Cu2+ (0,513 mg g-1) sobre a PN e Cr3+ (1,932 mg g-1) > Ni2+ (0,514 mg g-1) > Cu2+ (0,421 mg g-1) > Mn2+ (0,364 mg g-1) sobre a PE. Os dados experimentais se ajustaram melhor ao modelo de Langmuir em rela??o ao de Freundlich para os ?ons Cu2+, Mn2+ e Ni2+. No entanto, para os ?ons Cr3+, ambos, os modelos se ajustaram adequadamente aos dados experimentais

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-25T20:37:14Z No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-26T23:21:56Z (GMT) No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) / Made available in DSpace on 2016-04-26T23:21:56Z (GMT). No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) Previous issue date: 2015-07-01 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / No presente trabalho realizou-se o estudo da remo??o do negro de eriocromo T usando a perlita expandida modificada com ortofenantrolina, atrav?s da t?cnica de adsor??o. O estudo do processo de adsor??o foi realizado atrav?s da averigua??o do efeito da concentra??o inicial do corante, tempo de contato e varia??o de pH da solu??o (meio ?cido e alcalino) no processo de adsor??o, para um efluente denominado sint?tico (solu??o aquosa do negro de eriocromo T) e um efluente real (gerado a partir do ensaio de determina??o da dureza da ?gua, por titulometria de complexa??o). Os materiais foram caracterizados por Termogravimetria/An?lise T?rmica Diferencial (TG/DTA), Espectroscopia de absor??o na regi?o do infravermelho (IV), Difra??o de raios X (DRX) e Microscopia eletr?nica de varredura (MEV). Pelas an?lises de DRX observaram-se reflex?es referentes ? ortofenantrolina na perlita expandida modificada. E por an?lise de IV observou-se um aumento na intensidade e um minucioso alargamento da banda de absor??o referente ? deforma??o axial da liga??o O-H dos grupos silan?is da perlita (Si-OH). No estudo do tempo de equil?brio, na faixa de tempo avaliada (5 a 230 min) n?o foi poss?vel observar a exist?ncia de um tempo de equil?brio, provavelmente atribu?da ao tipo de intera??o entre o negro de eriocromo T e a perlita expandida modificada com ortofenantrolina, sendo uma intera??o de origem superficial. No estudo de efeito da concentra??o inicial do adsorbato, no caso 2,0x10-4 mol/L em pH natural (pH 5), obteve-se o maior valor de porcentagem de remo??o da cor do negro de eriocromo T, com 63,74 % de remo??o em 20 minutos de contato. Na avalia??o do efeito da varia??o do pH da solu??o de negro de eriocromo T no processo de adsor??o, concluiu-se que quanto mais ?cido o meio, maior a porcentagem de remo??o do corante, sendo resultado de uma intera??o ?cido-base entre o adsorbato e o adsorvente. No estudo da remo??o do negro de eriocromo T no efluente real empregou-se as condi??es otimizadas atrav?s do estudo com efluente sint?tico. A remo??o do corante em pH 10, ou seja, pH natural do efluente n?o foi significante alcan?ando-se o valor m?ximo de porcentagem de remo??o da cor de 8,12 %, j? em pH 3 obteve-se remo??o de cor m?xima de 100,00 % da cor, mais uma vez indicando que o negro de eriocromo T interage melhor e eficazmente com o adsorvente em valores de pH ?cido (pH 5 ou 3), e mais eficientemente em pH 3. Sendo assim pode-se citar que a perlita expandida (um aluminossilicato amorfo, naturalmente ?cido) modificada com ortofenantrolina (uma base de Bronsted), consiste em um material ex?mio e eficaz na remo??o de corantes do tipo ?cido de solu??es aquosas, nas condi??es expressas neste estudo, podendo ser aplicada como adsorvente deste corante tamb?m em um efluente real. / In this study, we carried out the study of Eriochrome black T removal using expanded perlite modified orthophenanthroline by adsorption technique. The study of the adsorption process was performed by investigating the effect of the initial dye concentration, contact time and pH range of the solution (acidic and alkaline) in the adsorption process, for a so-called synthetic effluent (aqueous solution of black eriochrome T) and a real effluent (generated from the test for determining the water hardness, by complexation titration). The materials were characterized by Thermogravimetry / Differential Thermal Analysis (TG / DTA), absorption spectroscopy in the infrared (IR), X-ray Diffraction (XRD) and scanning electron microscopy (SEM). By analysis of XRD observed thinking on orthophenanthroline the modified expanded perlite. And by IR analysis showed an increase in intensity and a detailed enlargement of the absorption band related to the axial deformation of the OH bond of silanol groups of perlite (Si-OH). In the equilibration time of the study, in the evaluated time range (5-230 min) was not possible to observe the existence of a balance of time, probably attributed to the type of interaction between the Eriochrome black-T and the expanded perlite modified orthophenanthroline, being an interaction of surface origin. In the study effect of the initial concentration of the adsorbate in the case 2,0x10-4 mol / L natural pH (pH 5) gave the highest removal percentage value of eriochrome T black color with 63.74 % removal in 20 minutes of contact. In evaluating the effect of varying the pH of Eriochrome black T solution in the adsorption process, it was found that the more acidic the environment, the greater the percentage stain removal, being a result of acid-base interaction between the adsorbate and the adsorbent. In T Eriochrome black removal study in real effluent we used the optimized conditions by studying with synthetic sewage. The dye removal at pH 10, natural pH of the effluent was no significant reaching the maximum amount of color removal percentage of 8.12%, obtained already at pH 3 with maximum color removal 100.00% of color, once more proving that eriochrome black T and effectively interact better with the adsorbent at acid pH values (pH 5 or 3), and most efficiently at pH 3. thus one can mention that the perlite expanded (an amorphous aluminosilicate naturally acid) modified with orthophenanthroline (one Bronsted base) consists of a master and effective removal of coloring material in the acid-type aqueous solution, the conditions expressed in this study, can be applied as an adsorbent of this dye also mums real effluent.

O objetivo do presente trabalho, consistiu na obtenção de ferro fundidos nodulares, a serem utilizados na fabricação de eixos, com as seguintes características mecânicas após os tratamentos térmicos adequados: limites de resistência à tração e escoamento mínimos de 700 N/mm2 e 450 N/mm2 respectivamente, alongamento mínimo de 5% e dureza entre 235 à 285 HB. A microestrutura mais adequada à obtenção das características mecânicas desejadas deveria consistir de cementita esferoidizada numa matriz ferrítica, a ser obtida com o tratamento de recozimento ou revenimento de microestruturas previamente perlíticas ou martensíticas, respectivamente. No caso do tratamento de recozimento, as estruturas iniciais consistiram de perlita grossa mais ferrita, presentes no material no estado bruto de fusão, ou, de perlita fina mais ferrita, do material normalizado. Todos os tratamentos térmicos utilizados, dependendo do tempo de tratamento, permitiram a obtenção de cementita esferoidizada. O material normalizado e recozido durante 2 horas a 700ºC, possibilitou a obtenção das propriedades mecânicas desejadas: limites de resistência à tração e de escoamento de 827 N/mm2 e 547 N/mm2 respectivamente, alongamento de 7% e dureza de 277 HB, valores estes, dentro dos limites desejados no presente trabalho. No caso do material temperado e revenido a 700ºC durante 0,5 hora, obteve-se limites de escoamento de 542 N/mm2, alongamento de 6% e dureza de 246 HB. O tratamento de recozimento realizado durante 48 horas, produziu microestrutura quase totalmente ferrítica, com pequenas áreas de agregados de carbonetos. O restante do carbono migrou para os nódulos de grafita secundária ao redor dos mesmos. / The purpose of the present work, consisted in obtaining ductile casting iron, that will be used in the shaft production, with de following mechanical properties after the appropriated heat treatments: ultimate tensile strength and yield strength values of 700 N/mm2 and 450 N/mm2 minimum respectively, elongation of 5% minimum and hardness value from 235 to 285 HB. The microstructure more adequated to obtaining the desired mechanical characteristics should consist of spheroidized cementite in a ferritic matrix, to be obtained with the annealing or tempering treatments of microstructures previously pearlitic or martensitic respectively. In the case of the annealing treatment, the initial structures consisted of thick pearlite plus ferrite, wich were in the material in the ascast state, or fine pearlite plus ferrite, of the normalized material. All the used heat treatment, depending on the time of treatment, allowed the obtainment of spheroidized cementite. The material normalized and annealed for 2 hours at 700°C made possible the obtaining of the desired mechanical properties: ultimate tensile strength and yield strength value of 827 N/mm2 and 547 N/mm2 respectively, elongation of 7% and hardness values of 277 HB, values these, in acordance with the aims initially proposed in the present work. In the case of the material quenched and tempered at 700°C for 0,5 hour, it was obtained yield strength values of 542 N/mm2, elongation of 6% and hardness value of 246 HB. The annealing treatment made during 48 hours, produced a microstructure almost totally ferritic, with small areas of aggregated carbides. The remaining of the carbon migrated to the graphite nodules producing secondary graphite around them.

A pesquisa relativa ao transporte ferroviário no Brasil tem se intensificado nos últimos anos visando principalmente a melhoria no desempenho do par rodatrilho. Isso se deve à demanda de se transportar cada vez mais carga por eixo com a finalidade de reduzir o custo de transporte. Através de mudanças na microestrutura do material ou de mudanças na composição das ligas utilizadas na fabricação pode se aumentar a resistência do par roda-trilho. Neste trabalho foi analisada a influência de diferentes microestruturas (puramente perlíticas e perlíticas-bainíticas), obtidas por meio de tratamento térmico por dilatometria, nas propriedades de um aço alto carbono similar ao utilizado em rodas convencionais classe C AAR destinadas ao transporte de carga pesada. As análises empregaram técnicas metalográficas (identificação de fases presentes e distância interlamelar da perlita), ensaios magnéticos (saturação magnética e ruído magnético de Barkhausen), ensaio mecânico de dureza e ensaio tribológico de resistência ao desgaste por deslizamento. Foram caracterizadas rodas ferroviárias classe C AAR em quatro condições distintas: usadas e novas, fundidas e forjadas. / Research about rail transport in Brazil has been intensified recently due the need to improve the wheel-rail performance, considering the demand of increasing axle load aiming for transportation cost reduction. Changes in the material microstructure or in the alloys composition can improve the wheel-rail resistance. A eutectoid steel similar to that used in conventional class C AAR wheels (designed to heavy haul transportation - high loads and low speeds) was submitted to isothermal heat treatments applying dilatometry techniques at ten different cycles. Different microstructures (totally pearlitic and pearlitic-bainitic) were obtained and their influence on the mechanical and magnetic properties was analyzed. The analysis included metallographic techniques (identification of phases and pearlite interlamellar spacing), magnetic testing (magnetic saturation and magnetic Barkhausen noise) and mechanical testing (hardness and pin-ondisc tests). Railway wheels Class C ARR were characterized in four different conditions: new and used, cast and forged.