A evolução do processo de reparo ósseo foi avaliada, em alvéolos dentários de ratos, frente ao coágulo sangüíneo, bem como ao implante de sulfato de cálcio di-hidratado e da hidroxiapatita BTCP GenPhos. Foram utilizados 48 ratos machos, divididos em três grupos, nos quais foi realizada a extração do incisivo superior direito. No grupo I, os alvéolos foram preenchidos com coágulo sangüíneo, permanecendo dessa forma como controle. No grupo II, implantou-se no alvéolo sulfato de cálcio di-hidratado e, no grupo III, realizou-se a inserção da hidroxiapatita BTCP GenPhos nos alvéolos. Após 7, 15 e 30 dias dos procedimentos cirúrgicos, os animais foram mortos, as hemimaxilas direitas removidas e processadas histologicamente para a realização das análises microscópicas descritiva e quantitativa, cujos resultados foram submetidos aos testes estatísticos de Kruskal-Wallis e Dunn. Foi possível concluir que o processo de reparo alveolar, aos 7, 15 e 30 dias, ocorreu de forma semelhante entre os grupos do coágulo sangüíneo, do sulfato de cálcio di-hidratado e da hidroxiapatita BTCP GenPhos, destacando-se a diferença significativa quanto à neoformação óssea, aos 15 dias, entre os grupos controle e hidroxiapatita BTCP GenPhos; e que, aos 30 dias, a evolução da neoformação óssea foi igual para todos os grupos analisados. / The evolution of bone repair was evaluated in tooth sockets of rats filled with blood clot as well as after placement of calcium sulfate dihydrate implant and hydroxyapatite BTCP GenPhos. The study sample was composed of 48 males rats divided into three groups, which were submitted to extraction of the right maxillary incisor. In group I, the sockets were filled with blood clot and were kept as such as control. Group II received a calcium sulfate dihydrate implant, and group III was submitted to placement of hydroxyapatite BTCP GenPhos in the sockets. At 7, 15 and 30 days after surgery, the animals were killed, the right hemimaxillae were removed and histologically processed for descriptive and quantitative microscopic analysis, whose results were statistically analyzed by the Kruskal-Wallis and Dunn tests. It was concluded that the alveolar repair process at 7, 15 and 30 days was similar for sockets filled with blood clot, calcium sulfate dihydrate and hydroxyapatite BTCP GenPhos, with emphasis to the significant difference with regard to new bone formation at 15 days between the control and hydroxyapatite BTCP GenPhos groups; and, at 30 days, the evolution of new bone formation was similar for all study groups

No description available.

A control diet (CN diet; 17.4% CP and 4.37% Ca) was compared with an experimental diet with a 0.4-percentage-unit reduction in protein content and a 35% replacement of limestone by a CaSO4-zeolite mixture [5.76% CaSO4 and 1.18% zeolite; reduced-emission diet (RE diet)] in laying hens to evaluate the effects on apparent N retention, egg production, egg composition, and excreta pH measured at excreta collection or after 7 d of storage. In previous studies, it was demonstrated that the RE diet reduced NH3 emissions by 48%. Laying hens (192 total; 48 replicate cages per diet, with 2 hens per cage) were fed experimental diets from 33 to 49 wk of age. Apparent N retention (48.2%), egg production (83.6%), and number of shell-less eggs (0.18%) were not affected by the diet. Eggs tended to be heavier (59.4 vs. 58.8 g/egg, P = 0.06), and yolk percentage (29.7 vs. 29.0%, P = 0.013) was greater with the RE diet. At 48 wk of age, the total solids content per egg was also greater from hens fed the RE diet (13.2 vs. 12.6 g/egg, P = 0.032). Other egg components were not influenced by diet. Thus, a slight reduction in dietary CP content and replacing a portion of the Ca from CaCO3 with CaSO4 did not affect egg production nor did it impair shell quality. At the end of the experiment, excreta were collected from all cages (excreta from 3 cages were mixed and pooled; 16 pools of excreta per diet). At collection, excreta of hens fed the RE diet had lower pH (5.89 vs. 6.54, P < 0.001) than those of hens fed the CN diet. After 7 d of storage, excreta pH of hens fed the RE diet continued to be lower (6.30 vs. 8.36, P < 0.001). The reduction of excreta pH, even after 7 d of storage, may control nitrogenous emissions from excreta by maintaining excreted N as NH4+.

Detectores de sulfato de cálcio ativado com cério IV e európio III utilizando o politetrafluoretileno (PTFE, Teflon®) free-flow como aglutinante (CaSO4:Ce,Eu + Teflon®) foram produzidos pelo método da estampagem, desenvolvido em colaboração com a empresa Tecnoflon, a partir de cristais crescidos de acordo com uma nova variação da rota da evaporação lenta, também apresentada nesse trabalho, com as concentrações de 0,16 mol% de Eu3+ e de 0,15 mol% de Ce4+ na solução ácida precursora. O modelo de dosímetro pessoal desenvolvido consiste em cinco detectores aderidos a um cartão de 30 x 48 mm de cloreto de polivinila (PVC) 95% opaco à luz na faixa do espectro eletromagnético que vai do infravermelho ao ultravioleta, idêntico aos cartões de identificação utilizados no IPEN, por uma tira de 10 x 35 mm de filme adesivo do mesmo material e foi submetido aos testes de aceitação descritos no regulamento técnico IRD-RT Nº 002.01/95, Desempenho de Sistemas de Monitoração Individual Critérios e Condições, sendo aprovado em todos os testes. Para a dosimetria clínica, os próprios detectores foram considerados dosímetros termoluminescentes e submetidos aos testes de aceitação descritos no código de práticas da Agência Internacional de Energia Atômica Technical Report Series Nº 398, Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water, [TRS-398, IAEA, 2000] adotado como protocolo de dosimetria pela maioria dos hospitais, sendo igualmente aprovados nesses testes. Os dosímetros desenvolvidos podem ser utilizados para a monitoração individual externa e para dosimetria clínica, apresentando a diferenciação do tipo e da energia da radiação com que foram irradiados e a redução de custos como as principais vantagens em relação aos dosímetros termoluminescentes atualmente utilizados nessas aplicações. / Calcium sulphate activated with cerium IV and europium III using the free-flow polytetrafluoroethylene (PTFE, Teflon®) as bonder were produced by the stamping method, developed by the collaboration of Tecnoflon industries, from crystals growth according to a new variation of the slow evaporation method, also described in this study, with Eu3+ and Ce4+ concentrations of respectively 0.15 mol% and 0.16 mol% in the precursory acid solution. The developed personal dosimeter consist of five detectors adhered to a 30 x 48 mm polyvinyl chloride (PVC) card 95% mat to light in the infrared to ultraviolet wavelengths, identical to the access cards used by IPEN staff, by a 10 x 35 mm adhesive strip of the same material and it passed the acceptance tests required by Brazilian national regulatory committee for appliance in individual monitoring of external exposure services. The own detector is considered a dosimeter as far as clinical dosimetry is concerned and it passed the acceptance tests suggested by the International Atomic Energy Agency in the Technical Report Series Nº 398, Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water, [TRS-398, IAEA, 2000] adopted as the dosimetry protocol by most hospitals. Hence, the developed dosimeters can be applied in the individual monitoring for external exposure and in the clinical dosimetry, having the radiation type and energy differentiation and the cost reduction as the key advantages over the currently used thermoluminescent dosimeters in such applications.

Detectores de sulfato de cálcio ativado com cério IV e európio III utilizando o politetrafluoretileno (PTFE, Teflon®) free-flow como aglutinante (CaSO4:Ce,Eu + Teflon®) foram produzidos pelo método da estampagem, desenvolvido em colaboração com a empresa Tecnoflon, a partir de cristais crescidos de acordo com uma nova variação da rota da evaporação lenta, também apresentada nesse trabalho, com as concentrações de 0,16 mol% de Eu3+ e de 0,15 mol% de Ce4+ na solução ácida precursora. O modelo de dosímetro pessoal desenvolvido consiste em cinco detectores aderidos a um cartão de 30 x 48 mm de cloreto de polivinila (PVC) 95% opaco à luz na faixa do espectro eletromagnético que vai do infravermelho ao ultravioleta, idêntico aos cartões de identificação utilizados no IPEN, por uma tira de 10 x 35 mm de filme adesivo do mesmo material e foi submetido aos testes de aceitação descritos no regulamento técnico IRD-RT Nº 002.01/95, Desempenho de Sistemas de Monitoração Individual Critérios e Condições, sendo aprovado em todos os testes. Para a dosimetria clínica, os próprios detectores foram considerados dosímetros termoluminescentes e submetidos aos testes de aceitação descritos no código de práticas da Agência Internacional de Energia Atômica Technical Report Series Nº 398, Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water, [TRS-398, IAEA, 2000] adotado como protocolo de dosimetria pela maioria dos hospitais, sendo igualmente aprovados nesses testes. Os dosímetros desenvolvidos podem ser utilizados para a monitoração individual externa e para dosimetria clínica, apresentando a diferenciação do tipo e da energia da radiação com que foram irradiados e a redução de custos como as principais vantagens em relação aos dosímetros termoluminescentes atualmente utilizados nessas aplicações. / Calcium sulphate activated with cerium IV and europium III using the free-flow polytetrafluoroethylene (PTFE, Teflon®) as bonder were produced by the stamping method, developed by the collaboration of Tecnoflon industries, from crystals growth according to a new variation of the slow evaporation method, also described in this study, with Eu3+ and Ce4+ concentrations of respectively 0.15 mol% and 0.16 mol% in the precursory acid solution. The developed personal dosimeter consist of five detectors adhered to a 30 x 48 mm polyvinyl chloride (PVC) card 95% mat to light in the infrared to ultraviolet wavelengths, identical to the access cards used by IPEN staff, by a 10 x 35 mm adhesive strip of the same material and it passed the acceptance tests required by Brazilian national regulatory committee for appliance in individual monitoring of external exposure services. The own detector is considered a dosimeter as far as clinical dosimetry is concerned and it passed the acceptance tests suggested by the International Atomic Energy Agency in the Technical Report Series Nº 398, Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water, [TRS-398, IAEA, 2000] adopted as the dosimetry protocol by most hospitals. Hence, the developed dosimeters can be applied in the individual monitoring for external exposure and in the clinical dosimetry, having the radiation type and energy differentiation and the cost reduction as the key advantages over the currently used thermoluminescent dosimeters in such applications.

Synthesis of hydroxyapatite (Ca10(PO4)6(OH)2, HAp) from commercial grade plaster of paris (CaSO4&bull / 0.5H2O, PoP) and gypsum (CaSO4&bull / 2H2O) has been performed. HAp synthesis was achieved by reacting 1 M of (NH4)2HPO4 (or 0.5 M of (NH4)2HPO4) solutions with solid calcium sulfate precursors under ambient pressure (1 atm) and hydrothermal-like (2 &plusmn / 0.2 atm, 120 &deg / C) conditions. Under ambient conditions, HAp formation kinetics was investigated at 25 &deg / C, 50 &deg / C and 90 &deg / C using 1 M of (NH4)2HPO4 solution. Conversion to HAp at such low temperature takes more than 21 days and it also promotes formation of additional calcium phosphate with HAp. At 25 &deg / C, HAp formation started after 7 days accompanied with formation of brushite (CaHPO4&bull / 2H2O). At 50 &deg / C no significant conversion was observed after 6 h. However, at 90 &deg / C, phase pure HAp was formed after 2 h. On the other hand, under hydrothermal-like conditions, the HAp formation proceed much faster and it was also shown that HAp could be also synthesized from gypsum powders and bulk gypsum pellets. Using 1 M of (NH4)2HPO4 solution, HAp formation from PoP started 15 min and completed almost in 30 min, whereas 0.5 M of (NH4)2HPO4 reactant solution slowed down the conversion. The exact chemical identity of the HAp product of hydrothermal-like reaction was evaluated by post-synthesis calcinations and the thermal phase stability was related with the stoichiometry (Ca/P at ratio) of the HAp. The HAp phase was stable up to 600 &deg / C and above 600 &deg / C, &beta / -tricalcium phosphate (&beta / -Ca3(PO4)2, &beta / -TCP) was formed, suggesting that the resultant HAp was calcium-deficient. Mechanical testing by diametrical compression was performed to the HAp samples produced from bulk gypsum pellets. The strength was measured 1.2 MPa with highest solid to liquid (s:l) ratio 3.33 and decreased with s:l ratio. This change was found to be related with the porosity differences due to differences in s:l ratio. Additional mechanical tests were applied to the polycaprolactone (PCL) coated bulk HAp pellets for which the tensile strength was doubled. This study presents an easy and feasible method for production of HAp from a cheap and abundant calcium source &ndash / PoP. In addition, the findings provide a potential processing route for developing irregularly shaped bulk porous HAp structures.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2016-01-13T15:38:59Z No. of bitstreams: 2 Tese - Edgard Alves Muniz - 2015.pdf: 1352609 bytes, checksum: c9b3cdfa4970aae68eeb4f9b944894ed (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2016-01-13T15:42:17Z (GMT) No. of bitstreams: 2 Tese - Edgard Alves Muniz - 2015.pdf: 1352609 bytes, checksum: c9b3cdfa4970aae68eeb4f9b944894ed (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-13T15:42:17Z (GMT). No. of bitstreams: 2 Tese - Edgard Alves Muniz - 2015.pdf: 1352609 bytes, checksum: c9b3cdfa4970aae68eeb4f9b944894ed (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-05-21 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The latosolic Concretionary Petric Plintosol is the less fertile soil in the bioma Cerrado. Making it to produce food in order to contribute to the Brazilian agribusiness, turns into a great challenge for Science. In addition to this fact, the\pineapple fruits exports are important incomes sources for our Country. For this reason, the present work aimed to assess effects of application, on soil, of calcium carbonate, calcium & magnesium carbonate and calcium sulfate, on productivity of pineapple plant (Ananas comosus L. Merril) var. Pérola cultivated in typical Distrocohesive Yellow Latosol and latosolic Concretionary Petric Plintosol on a same topossequence of Cerrado bioma. Soon after planting, it were applied on both soils, the following equivalent doses\(kg ha-1): on the latossol area – 2000, 2000 and 1000; and on the plintossol area – 3000, 3000 and 1500; of calcium carbonate, calcium & magnesium carbonate and calcium sulfate, respectively. As effects, the fruits production averages (t ha-1), in both soils were: 8,32; 12,94; 13,82; 15,09; 5,02; 12,60; 14,11; e 14,82, respectively, in the same sequence above. The essays were set up in 2010, in a region of Anápolis, Goiás State, latitude 16º19ˈ 36 ̎ S, longitude 48º57ˈ 10 ̎ W and altitude 1017 m. The yearly pluviosity average is 1.200 mm, and the temperature oscillates between 21 and 35ºC; the climate is classified as Aw according to Köppen system. The harvest was achieved in 2012. The experimental design was in randomized blocks. Each plot measured 1,20 x 6,60 m and were four the number of treatments with five replications. The three products, in the mentioned equivalent doses, induced the latosolic Concretionary Petric Plintosol studied to reach a pineapple Pérola production capacity equivalent to the typical Distrocohesive Yellow Latosol. Calcium sulfate, calcium carbonate and calcium & magnesium carbonate, individually, increased the tenor of changeable bases in the upper layers of both soils, wich made it possible to obtain greater pineapple Pérola yielding. / Plintossolo Pétrico Concrecionário latossólico é o menos fértil dos solos cerradinos. Fazê-lo produzir alimentos para contribuir com o agronegócio brasileiro, tornase um desafio para a ciência. Em adição a este fato, abacaxi é uma importante fonte de divisas para o país. Por estas razões, o presente trabalho objetivou avaliar efeitos de aplicações, no solo, de calcário calcítico, calcário dolomítico e gesso agrícola sobre a produtividade do abacaxizeiro (Ananas comosus L. Merril) var. Pérola cultivado em Latossolo Amarelo Distrocoeso típico e em Plintossolo Pétrico Concrecionário latossólico de uma mesma topossequência de bioma Cerrado. Logo após o plantio, foram aplicadas, aos dois solos, as seguintes doses equivalentes (kg ha-1): na área de latossolo – 2.000, 2.000 e 1.000; e na área de plintossolo – 3000, 3000 e 1 .500 de calcário calcítico, calcário dolomítico e gesso agrícola, respectivamente. Como efeitos, as produções médias de frutos (t ha-1), nos dois solos, foram: 8,32; 12,94; 13,82; 15,09; 5,02; 12,60; 14,11; e 14,82, na mesma ordem das doses equivalentes descritas acima. Os ensaios foram instalados em 2010, no município de Anápolis (GO), com latitude de 16º19ˈ 36 ̎ S, longitude 48º57ˈ 10 ̎ W e altitude 1017 m. A média anual de pluviosidade é de 1.200 mm e a temperatura oscila entre 21 e 35ºC; clima é classificado como Aw no sistema Köppen. A colheita realizou-se em 2012. O delineamento experimental foi em blocos ao acaso. Cada parcela mediu 1,20 x 6,60 m, e foram quatro os tratamentos de cinco repetições. Os três insumos, nas doses equivalentes mencionadas, induziram o Plintossolo Pétrico Concrecionário latossólico estudado a atingir uma capacidade de produção de abacaxi Pérola estatisticamente igual à do Latossolo Amarelo Distrocoeso típico. O gesso agrícola, o calcário dolomítico e calcário calcítico, individualmente, aumentaram os teores de bases trocáveis nas camadas mais superficiais dos dois solos, o que possibilitou a obtenção de maiores produtividades do abacaxizeiro Pérola.

Made available in DSpace on 2014-06-11T19:28:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2005Bitstream added on 2014-06-13T19:15:54Z : No. of bitstreams: 1 deliberador_tm_me_araca.pdf: 2630912 bytes, checksum: a0347c4bc88ad360bdf74a6658873848 (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo deste estudo foi avaliar, histologicamente, o processo de cicatrização de defeitos de furca Classe II, criados cirurgicamente em cães e tratados com enxerto de osso autógeno (OA) associado ou não à barreira de sulfato de cálcio (SC). Os segundos, terceiros e quartos pré-molares mandibulares de 6 cães foram usados neste estudo. Defeitos de furca Classe II (5 mm de altura x 2 mm de profundidade) foram criados cirurgicamente e imediatamente tratados. Os dentes foram aleatoriamente divididos em 3 grupos: Grupo C (controle): o defeito foi preenchido somente com coágulo sanguíneo; Grupo OA (osso autógeno): o defeito foi preenchido com enxerto de OA; Grupo OA/SC (osso autógeno/sulfato de cálcio): o defeito foi preenchido com enxerto de OA e coberto com barreira de SC. Os retalhos foram suturados de forma a cobrir totalmente os defeitos. A eutanásia dos animais foi realizada aos 90 dias pós-operatórios. Foram obtidos cortes histológicos seriados mésio-distais, corados com HE ou Tricrômico de Masson. Cinco cortes de cada dente foram selecionados para análises histológica e histométrica. Foram avaliadas medidas lineares e medidas de área da cicatrização periodontal. Esses parâmetros foram apresentados como porcentagem do defeito original e transformados em arcoseno para análise estatística (ANOVA, p < 0,05). A regeneração periodontal ocorreu de forma similar nos três grupos, não sendo observada completa neoformação óssea e de tecido conjuntivo na maioria dos espécimes. Diferenças estatisticamente significativas não foram constatadas entre os três grupos em nenhum dos parâmetros avaliados. A cicatrização periodontal foi similar após o tratamento de defeitos de furca Classe II com enxerto de OA, enxerto de OA com barreira de SC ou debridamento cirúrgico somente. / The purpose of this study was to histologically analyze the healing of surgically created Class II furcation defects treated using an autogenous bone (AB) graft with or without a calcium sulfate (CS) barrier. The second, third and fourth mandibular premolars of 6 mongrel dogs were used in this study. Class II furcation defects (5 mm in height x 2 mm in depth) were surgically created and immediately treated. Teeth were randomly divided into 3 groups: Group C (control): the defect was filled with blood clot; Group AB: the defect was filled with AB graft; Group AB/CS: the defect was filled with AB graft and covered by a CS barrier. Flaps were repositioned to cover all defects. The animals were euthanized at 90 days postoperative. Mesio-distal serial sections were obtained and stained with either H&E or Masson's Trichrome. Histometric, using image analysis software, and histologic analyses were performed. Linear and area measurements of periodontal healing were evaluated and calculated as a percentage of the original defect. Percentage data were transformed into arccosine for statistical analysis (ANOVA, p<0.05). Periodontal regeneration in the 3 groups was similar. Regeneration of bone and connective tissue in the furcation defects was incomplete in most of the specimens. Statistically significant differences were not found in any of the evaluated parameters among the groups. Periodontal healing was similar wheter using surgical debridement alone, AB graft, or AB graft with a CS barrier in the treatment of Class II furcation defects.

Les liants ettringitiques dont la composition est formée principalement par du ciment d’aluminate de calcium et par du sulfate de calcium, sont très utilisés dans le cadre des mortiers techniques pour des applications telles que les mortiers de ragréage, les chapes autonivelante, les mortiers de réparation…. en raison de leurs propriétés de durcissement rapide et de résistance initiale élevée. Néanmoins, en fonction de la quantité des matières premières utilisées dans la composition et de leur nature, ces liants peuvent présenter à jeune âge ainsi qu’à long terme, des comportements différents. En particulier et dans le cadre de ce travail, l’influence de la nature et du dosage en sulfate de calcium sur l’hydratation des mortiers ettringitiques comme le début de prise, le changement de l’état liquide à l’état solide, les variations dimensionnelles, la résistance et le vieillissement à long terme (jusqu’à 330 jours) pour différentes conditions de conservations ont été déterminées. Ces caractéristiques ont été évaluées selon différentes techniques expérimentales de rhéologie, de mesure des variations volumiques, de calorimétrie isotherme, de spectroscopie infrarouge, de porosimétrie par intrusion de mercure, de diffraction des rayons X et thermogravimétrie. / The ettringite binder whose composition is mainly formed by the calcium aluminate cement and calcium sulfate, are widely used in mortars for technical applications such as patching mortars, the self -leveling screeds, repair mortars etc… thanks to their fast hardening ability and high early strength. However, depending on the amount and types of raw materials used in the composition, the properties of these types of binder have different behaviors at early age and at long-term. And in particular in this work, the influence of the nature and dosage of calcium sulfate on the consequences of ettringite mortars hydration as the beginning of setting time, the change from the liquid state to the solid state, dimensional change, the resistance, porosity, the progress of hydration and ageing until 330 days at different conservation conditions were determined. These characteristics were assessed by different experimental techniques such as rheology, chemical shrinkage, autogenous shrinkage, isothermal calorimetry, infrared spectroscopy, mercury intrusion porosimetry, X-ray diffraction, Thermogravimetric analysis.

[pt] SO2 é conhecido com um grande contaminante ambiental e muitos países estabeleceram regras para o controle da sua emissão para a atmosfera. Como resultado a maioria das plantas fornecedoras de energia foram equipadas com instalações de dessulfurização de gases de combustão. Embora esta tecnologia seja bem sucedida no abate de SO2, ela gera uma grande quantidade de gesso FGD (flue gas desulfurization) como resíduo. Grandes esforços estão sendo feitos para aproveitar este resíduo (gesso FGD). No presente estudo o gesso FGD foi avaliado como aditivo retardador do tempo de pega substituindo o gesso natural na fabricação do cimento Portland (CP II E-32). Os resultados da caracterização físico-química e morfológica do gesso natural e de gesso FGD identificam um material de alta pureza, sulfato de cálcio di-hidratado para o gesso natural, e presença principalmente de bassanita (CaSO4.0,6H2O) e hannebachite (CaSO3.0,5H2O) com baixas concentrações de impurezas no gesso FGD. Baseado nos resultados, o gesso FGD é uma alternativa adequada para substituir o gesso natural. O tempo de pega mostrou cerca de uma hora de retardo em comparação com gesso natural e seu efeito sobre a resistência à compressão para as amostras de 3, 7 e 28 dias depende da composição das misturas, atingindo um valor máximo para a argamassa com 2,1 porcento de gesso FGD e 1,4 porcentode gesso natural. Também foi estimado o impacto ambiental do gesso FGD, examinando a liberação de seus constituintes inorgânicos seguindo a norma ABNT NBR 10004:2004 e classificando o resíduo como não perigoso e não inerte. / [en] The SO2 is well known as an important environmental contaminant and many countries have established rules to control its emission to the atmosphere and as result most of power supply plants were equipped with flue gas desulfurization systems. Although this technology is successful in the discharge of SO2, its generates a large amount of gypsum FGD (flue gas desulfurization) as a residue. Great efforts are being made to find destinations for this residue. In the present study, the FGD gypsum was evaluated as setting retarder to replace the natural gypsum in the production of Portland cement (CP II E-32). The results of physical-chemistry and morphological characterization of both products, natural and FGD gypsum showed a material of high purity, calcium sulfate dehydrate for natural gypsum, and the presence of bassanite (CaSO4.0,6H2O) and hannebachite (CaSO3.0,5H2O) with low concentrations of impurities for FGD gypsum. Based on the results, the FGD gypsum is a suitable alternative to replace natural gypsum. The setting time with FGD gypsum showed about 1 hour delay compared with natural gypsum and its effect on compressive strength, for samples of 3, 7 e 28 days, depend the composition of the mixtures, reaching the maximum value for the mixture of 1,4 weight percent natural gypsum and 2,1 weight percent FGD gypsum. The FGD gypsum environmental impact was evaluated by determining its potential in releasing inorganic constituents, following the standard ABNT NBR 10004:2004, and it was classified as a non-hazardous and non-inert.