Resumen. Los hidrogeles biodegradables obtenidos de fuentes naturales son materiales no tóxicos y con una gran capacidad de retención de agua, por lo que constituyen una valiosa alternativa para el uso racional del agua en aplicaciones agrícolas. El objetivo del presente trabajo fue evaluar el efecto de hidrogeles formulados a partir de polímeros naturales (alginato, polisacáridos de nopal, polisacáridos de aloe y quitosano) sobre la capacidad de retención de agua, el potencial biodegradable, así como la morfometría y germinación de plántulas de alfalfa en comparación con el hidrogel de poliacrilato de potasio (control comercial). Se caracterizaron un total de 36 tratamientos bajo condiciones controladas a nivel laboratorio, obteniendo que, en comparación con el control comercial, el hidrogel de PSGCL presentó el mayor valor de retención de agua y todos los demás tratamientos obtenidos a partir de polímeros naturales presentaron mayor potencial biodegradable. En cuanto a la germinación de plántulas de alfalfa respecto al testigo absoluto y al resto de los tratamientos.

Abstract. Biodegradable hydrogels obtained from natural sources are non-toxic materials with a large water retention capacity, hence a valuable alternative for the rational use of water in agriculture applications. The aim of the present work was to evaluate the effect of hydrogels formulated from natural polymers (alginate, nopal polysaccharides, aloe polysaccharides, and chitosan) on water retention capacity, biodegradable potential as well as the morphometry and germination of alfalfa seedlings compared with potassium polyacrylate hydrogel (commercial control). A total of 36 treatments were characterized under controlled conditions at the laboratory level obtaining that in comparison with the commercial control, PSGCL hydrogel presented the highest water retention value, whereas all the hydrogels obtained from natural polymers had greater biodegradable potential. Regarding to germination of alfalfa seedlings, PSGP hidrogel presented the most outstanding performance in term of percentage of germination, plant height and foliage development with respect to absolute control and the rest of the treatments.

Abstract Two different reactive concentrated magnesium hydroxide (HM) pulps, produced in a lab reactor mill, and a synthetic and non-reactive HM-pulp, for comparative analyses, have been prepared and studied. Sodium polyacrylate was selected as a dispersant for improving the HM pulp fluidity, with concentrations varying from 0.42% to 2.0% on a dry basis. The two reactive pulps differed from each other mainly by the impurity level and for both, a residual MgO amount was detected, implying that the hydration reaction could proceed. Results (with and without dispersant) confirmed the formation of particle clusters as HM concentration rose until a critical value, above which the pulp behaved as a solid. Reactive HM-pulps with high impurities may represent a limiting factor in the drying operation. Among all HM-pulps studied, the purest reactive pulp with 1% dispersant presented the best flow behavior making this reactive pulp the most suitable to be tested in a pilot spray dryer. (HM mill nonreactive non HMpulp, HMpulp pulp, HM-pulp analyses studied fluidity 042 0 42 0.42 20 2 2.0 basis both detected proceed value solid HMpulps operation 1 dryer 04 4 0.4 2. 0.

Abstract Composites are relevant to high-performance materials in the aerospace sector and have attracted the attention of the scientific and technological communities. Bentonites present very fine granulometry which enables their use in composites. This study showed the development of water absorbent composite based on sodium polyacrylate, bentonite coated by epoxy resin. Since there are gaps in the quantification of composite materials by near-infrared spectroscopy, especially by reflectance analysis (NIRA), this paper shows a quantification methodology (A7200/A5202) of sodium polyacrylate and bentonite. The methodology error found was 1.45% (95% of coefficient of determination). The effectiveness of the developed infrared methodology was verified showing that values are close to the nominal, especially for lower bentonite content. Besides, scanning electron microscopy (SEM) and universal attenuated total reflection (UATR) analysis evidenced the coating with the epoxy resin. Such development ensures rapid and precise methodologies that can be applied to the quality control of composite materials. highperformance high performance communities composites resin nearinfrared near spectroscopy NIRA, NIRA , (NIRA) A7200/A5202 A7200A5202 AA A7200 A5202 A (A7200/A5202 145 1 45 1.45 95% 95 (95 determination. determination . determination) nominal content Besides SEM (SEM UATR (UATR (NIRA A7200/A520 A7200A520 A720 A520 (A7200/A520 14 4 1.4 9 (9 A7200/A52 A7200A52 A72 A52 (A7200/A52 1. ( A7200/A5 A7200A5 A7 A5 (A7200/A5 A7200/A A7200A (A7200/A

Resumo Considerando-se que os substratos apresentam constituições físico-químicas diversas e que a liberação de íons do substrato, ou a adição de fertilizantes, eleva a condutividade elétrica da solução, este trabalho teve como objetivo avaliar a retenção de água em substratos com hidrogel com presença e ausência de adubação. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 3 x 2, com quatro repetições. Os fatores constituíram de quatro tipos de substratos (casca de pinus compostada, pó-de-coco (fibra do mesocarpo triturada), turfa de Sphagnum e substrato comercial (à base de turfa de Sphagnum, vermiculita expandida, casca de arroz torrefada, calcário dolomítico e gesso agrícola), três formas de aplicação do produto hidrogel (sem aplicação, com aplicação sem pré-hidratação e com aplicação após hidratação) e duas formas de aplicação de fertilização de base (na presença e ausência). O hidrogel utilizado foi um copolímero de poliacrilato de potássio (K2S2O8). Os resultados apontam que a adição de hidrogel promove melhorias na capacidade de retenção de água dos substratos, contudo, é influenciada pela sua composição e pela presença de fertilizantes químicos. Quanto maior a Condutividade Elétrica (CE) do substrato, menor é o potencial de hidratação do hidrogel. A forma de aplicação do hidrogel, se seco ou pré-hidratado, não influencia a capacidade de retenção de água pelos substratos. O hidrogel aplicado no substrato, uma vez desidratado, mantém sua capacidade de reidratação.

Abstract Considering that the substrates have different physical and chemical constitutions and that the release of ions from the substrate or the addition of fertilizers increases the electrical conductivity of the solution, the objective of this work was to evaluate the water retention in substrates with hydrogel, without and with fertilization. The experimental design used was a completely randomized, in a 4 x 3 x 2 factorial scheme, with four replications. The factors consisted of four substrates (composted pine bark, coconut powder (crushed mesocarp fiber), Sphagnum peat and commercial substrate (based on Sphagnum peat, expanded vermiculite, roasted rice husk, dolomitic limestone and plaster), three forms of application of the hydrogel product (without application, with application without pre-hydration and with application after hydration) and two ways of applying the basic fertilization (present and absent) .The hydrogel used was a potassium polyacrylate copolymer (K2S2O8). The results show that the addition of hydrogel promotes improvements in the water retention capacity of the substrates However, it is influenced by its composition and by the presence of chemical fertilizers. The higher the EC of the substrate, the lower the hydration potential of the hydrogel. The hydrogel application method, whether dry or pre-hydrated, does not influence the water retention capacity by the substrates. The hydrogel applied to the substrate once dehydrated, maintains its ability to rehydrate.

Abstract Palygorskite (Pal) is a natural clay mineral with fibrous morphology and high surface area. Depending on the geological origin, it presents impurities, such as quartz and carbonates, which can harm some of its properties. Therefore, this work seeks to define a viable methodology for the purification of a Brazilian Pal. Two types of mixing processes (sonication and milling) and two types of dispersing agents (sodium silicate and sodium polyacrylate) were investigated. In addition, a subsequent acid activation with hydrogen peroxide and sulfuric acid was performed for complete purification. The viability of the purification of Pal was confirmed by X-ray diffraction, X-ray fluorescence, and thermogravimetric analyses. The sonication mixture process and the use of sodium polyacrylate as a dispersing agent were more effective. In addition, BET analysis showed an increase in the surface area of Pal, and scanning electron microscopy confirmed the permanence of its fibrous morphology after the purification steps.

Xylopia aromatica (Lam.) Mart. (Annonaceae) is a typical species from the Brazilian cerrado that presents medicinal properties. The plant is distinguished by its large white flowers which produce a pleasant fragrance. X. aromatica is characterized by a wide range of medicinal application. These characteristics have motivated us to investigate the flowers volatile organic compounds (VOCs) via in vivo and in vitro protocols by a headspace solid-phase microextraction (HS-SPME) technique combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Four different fibers, extraction times and temperatures were the parameters changed to lead to the maximum profiling of the volatile constituents. Data were analyzed using principal component analysis (PCA). A total of 77 VOCs were extracted from the floral scent, with 52 and 68 extracted from in vivo and in vitro sampling, respectively, of which 48 were reported for the first time in the literature as volatile constituents from X. aromatica flowers. The extraction and identification of VOCs were successfully performed through HS-SPME/GC-MS. The PCA data allowed the identification of parameters that led to the maximum number of VOCs, which were polyacrylate (PA) and carboxen/polydimethylsiloxane (CAR/PDMS) fibers, 60 min extraction time and temperature of 29.0 °C. Among the volatile constituents identified, sesquiterpenes predominated, comprising about 61.04%.

RESUMO Determinou-se a composição do perfil volátil de frutos de cambuizeiro (Myrciaria floribunda) utilizando-se microextração em fase sólida no modo headspace e cromatografia gasosa acoplada a espectrometria de massas. As fibras PA (polyacrylate) e DVB/CAR/PDMS (divinylbenzene/carboxen/polydimethylsiloxane) foram otimizadas quanto aos parâmetros de extração (agitação, tempo e temperatura de extração), a fim de selecionar a fibra com maior número de compostos isolados. Um total de 48 compostos voláteis foram identificados através do HS-SPME / GC-MS presentes nos frutos maduros de cambuí. Os compostos voláteis foram classificados em cinco classes químicas, sendo a maioria pertencente à classe dos sesquiterpenos (71 %). Além disso, foi possível verificar que a fibra revestida com poliacrilato (PA) teve melhor desempenho, permitindo a extração de um maior número de compostos voláteis (n = 35). As condições de extração que permitiram o isolamento de um maior número de compostos voláteis, corresponderam a tempos superiores de 26 min e temperaturas acima de 85 °C com agitação de 79 rpm, isto para a fibra PA. Da mesma forma, verificou-se que os sesquiterpenos hidrocarbonetos foi a classe química mais presente nos frutos, o que está relacionado principalmente ao perfil volátil dos frutos de cambuí.

ABSTRACT The composition of the volatile profile of rumberry fruits (Myrciaria floribunda) was determined using solid- phase microextraction in headspace mode and gas chromatography, coupled with mass spectrometry. The PA (polyacrylate) and DVB/CAR/PDMS (divinylbenzene/carboxen/polydimethylsiloxane) fibers were optimized for the extraction parameters (agitation, extraction time and temperature), in order to select the fiber with the highest number of isolated compounds. A total of 48 volatile compounds were identified using HS-SPME/GC-MS present in the ripe fruits of rumberry. The volatile compounds were classified into five chemical classes, the majority belonging to the sesquiterpenes class (71%). In addition, it was possible to verify that the fiber coated with polyacrylate (PA) had better performance, allowing for the extraction of a greater number of volatile compounds (n = 35). The extraction conditions that allowed the isolation of a greater number of volatile compounds corresponded to times greater than 26 minutes and temperatures above 85 °C, with agitation of 79 rpm for the PA fiber. Likewise, it was found that the hydrocarbon sesquiterpenes was the chemical class most present in the fruits, which is mainly related to the volatile profile of rumberry fruits.

This work proposes a novel approach for colorimetric assays using ubiquitous and inexpensive water beads (WBs) made of a superabsorbent polymer (sodium polyacrylate). The high-water absorption capacity by the WBs was exploited for the preconcentration of iron ions from samples of tap, well, and lake waters. Moreover, the WBs also worked as a substrate for colorimetric detection of iron by the classical reaction of formation of Fe(II)-phenanthroline complex. Digital images acquired with a smartphone were used to obtain the color intensity of the WBs containing the orange color complex. The WBs were able to uptake and preconcentrate iron ions, allowing colorimetric detection with good linearity (R2 = 0.9978) and limits of detection (LOD) and quantification (LOQ) of 0.02 and 0.07 mg L-1, respectively. The proposed method provided recoveries ranging from 93 to 111% for a sample of well water spiked with 0.15 mg L-1 of iron.

Resumo O objetivo deste estudo foi avaliar o efeito de diferentes fases líquidas comerciais (Ketac, Riva e Fuji IX) e o uso de partículas esféricas de vidro pré-reagido (SPG) na maturação do cimento, liberação de flúor, força de compressão (CS) e resistência biaxial à flexão (BFS) de cimentos de ionômero de vidro (GICs) experimentais. Os GICs experimentais (Ketac_M, Riva_M, FujiIX_M) foram preparados pela mistura de partículas SPG com fases líquidas comerciais usando a proporção de pó para massa líquida de 2,5: 1. O FTIR-ATR foi usado para avaliar a maturação dos GICs. O coeficiente de difusão do flúor (DF) e a liberação cumulativa de flúor (CF) em água deionizada foram determinados usando o eletrodo específico do íon fluoreto (n = 3). CS e BFS em 24 h também foram testados (n = 6). GICs comerciais foram usados como comparações. Riva e Riva_M exibiram rápida formação de sal de poliacrilato. Os maiores DF e CF foram observados com Riva_M (1,65x10-9 cm2/s) e Riva (77 ppm), respectivamente. O uso de partículas SPG melhorou o DF de GICs em média de ~ 2,5x10-9 cm2/s a ~ 3,0x10-9 cm2/s, mas reduziu o CF dos materiais em média de ~ 51 ppm a ~ 42 ppm. O CS e BFS de Ketac_M (144 e 22 MPa) e Fuji IX_M (123 e 30 MPa) foram comparáveis aos materiais comerciais. Usar SPG com Riva reduziu significativamente CS e BFS de 123 MPa para 55 MPa e 42 MPa para 28 MPa, respectivamente. O uso de SPG partículas melhorou o DF, mas reduziu o CF dos GICs. O uso de partículas SPG com líquidos Ketac ou Fuji IX proporcionou resistência comparável aos materiais comerciais.

Abstract The aim of this study was to assess the effect of different commercial liquid phases (Ketac, Riva, and Fuji IX) and the use of spherical pre-reacted glass (SPG) fillers on cement maturation, fluoride release, compressive (CS) and biaxial flexural strength (BFS) of experimental glass ionomer cements (GICs). The experimental GICs (Ketac_M, Riva_M, FujiIX_M) were prepared by mixing SPG fillers with commercial liquid phases using the powder to liquid mass ratio of 2.5:1. FTIR-ATR was used to assess the maturation of GICs. Diffusion coefficient of fluoride (DF) and cumulative fluoride release (CF) in deionized water was determined using the fluoride ion specific electrode (n=3). CS and BFS at 24 h were also tested (n=6). Commercial GICs were used as comparisons. Riva and Riva_M exhibited rapid polyacrylate salt formation. The highest DF and CF were observed with Riva_M (1.65x10-9 cm2/s) and Riva (77 ppm) respectively. Using SPG fillers enhanced DF of GICs on average from ~2.5x10-9 cm2/s to ~3.0x10-9 cm2/s but reduced CF of the materials on average from ~51 ppm to ~42 ppm. The CS and BFS of Ketac_M (144 and 22 MPa) and Fuji IX_M (123 and 30 MPa) were comparable to commercial materials. Using SPG with Riva significantly reduced CS and BFS from 123 MPa to 55 MPa and 42 MPa to 28 MPa respectively. The use of SPG fillers enhanced DF but reduced CF of GICs. Using SPG with Ketac or Fuji IX liquids provided comparable strength to the commercial materials.

RESUMO A capacidade de hidratação do hidrogel em solução foi avaliada em diferentes níveis de condutividade elétrica (CE), usando nitratos, fosfatos, sulfatos e sais de cálcio, magnésio e potássio. Foram realizados quatro experimentos sequenciais, utilizando-se um copolímero de poliacrilato de potássio. O primeiro ensaio objetivou determinar a menor dose de hidrogel, na qual se obtivesse a máxima absorção de água deionizada e foi montado num delineamento inteiramente casualizado, com seis doses de hidrogel (1, 2, 4, 6, 8 e 10 g L-1) e quatro repetições. O segundo estudo, montado num delineamento experimental inteiramente casualizado, com quatro repetições, consistiu em testar doses de sacarose P.A. (0, 1, 2, 4 e 6 %), afim de avaliar a alteração no potencial osmótico da solução sobre a hidratação do hidrogel. O terceiro e o quarto estudos foram desenvolvidos em delineamento inteiramente casualizado, num esquema fatorial 6 × 3 × 2, com quatro repetições. Para o terceiro estudo, os fatores constituíram de seis níveis de CE (0; 0,25; 0,50; 1,00; 1,50 e 2,00 mS cm-1), elevada pela adição de três ânions (NO3-; PO43- e SO42-), acompanhados pelos contra-íons Ca++ e K+. Para o quarto estudo, os mesmos seis níveis de CE foram atingidos pela adição de três cátions (Ca++, Mg++ e K+), acompanhados pelos contra-íons Cl- e SO42-. A capacidade de hidratação do hidrogel reduz com a elevação da concentração iônica da solução e que a redução do potencial osmótico, pela adição de sacarose, não interfere na sua capacidade de intumescimento. Os ânions e cátions em solução influenciam negativamente no processo de hidratação do hidrogel, sendo o efeito mais pronunciado para aqueles de maior valência..

ABSTRACT Hydrogel hydration capacity in solution was evaluated at different levels of electrical conductivity (EC) using nitrate, phosphates, sulfates, and salts of calcium, potassium and magnesium. Four sequential experiments were performed using potassium polyacrylate copolymer. The first experiment aimed to determine the lowest hydrogel dose, at which occur maximum deionized water absorption. The test was assembled in a completely randomized design with six hydrogel doses (1, 2, 4, 6, 8 and 10 g L-1) and four replicates. The second experiment consisted of testing the sucrose P.A. doses (0, 1, 2, 4 and 6 %) in order to evaluate the change in osmotic potential of the solution on hydrogel hydration. The third and fourth studies were carried out in a complete randomized design, using a 6 x 3 x 2 factorial scheme with four replicates. For the third experiment, the factors were six levels of EC (0; 0.25; 0.50; 1.00; 1.50 and 2.00 mS cm1) increased by the addition of three anions (NO3-; PO43- and SO42-) along with counter-ions Ca++ and K+. For the fourth experiment, the same six levels of EC were achieved by adding the three cations (Ca++, Mg++ and K+), along with the counter-ions Cl- and SO42-. Hydration capacity of the hydrogel decreases when the ionic concentration of the solution increases and the reduction of the osmotic potential through the addition of sucrose does not interfere in its swelling capability. Anions and cations in the solution negatively influence the process of the hydrogel hydration. The most pronounced effect is for those with higher valence.

The objective of this study was to explore the extraction and identification of volatile organic compounds (VOCs) present in cagaita fruit (Eugenia dysenterica). Parameters such as type of extraction fiber, agitation, extraction time and extraction temperature were investigated. Initially, the VOCs were extracted using headspace solid-phase microextraction. Then, the compounds were identified using gas chromatography coupled to mass spectrometry. Results revealed the presence of at least 26 different compounds and the polyacrylate (PA) fiber promoted the extraction of a larger number of VOCs. Regarding the PA fiber, the most efficient extraction was achieved using a 50 rpm agitation at 45 ºC for 30 min. The majority were monoterpenes (34.64%) and esters (36.28%). An increase in the extraction temperature promoted the isolation of more VOCs when using carboxen/polydimethylsiloxane (CAR/PDMS) and divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fibers. However, these fibers allowed the isolation of a smaller number of VOCs. The extraction time and agitation had no significant influence.

ABSTRACT Introduction: Various bulking agents were utilized for endoscopic correction of VUR. A study reviewing multi-institutional data showed that the amount of injection material has increased over time with the purpose of improving success rates, which also resulted in costs. We noticed an opposite trend in our center since we started using a new bulking agent. The aim of this study was to evaluate evolution of our practice with different bulking agents. Patients and Methods: Records of VUR patients who underwent subureteric injection with polyacrylate polyalcohol copolymer (PPC) and dextronomere hyaluronic acide (DxHA) between 2005 and 2014 were reviewed. Variation of different parameters throughout the study period was evaluated along with the success rate. Success was defined as complete resolution of reflux. Results: A total of 260 patients with 384 refluxing units were included. The success rate was higher in PPC group compared to DxHA group. There was no statistically significant difference between years regarding distribution of VUR grade, body weight, patient height, and age in PPC group. Despite significant reduction in injection volume, success rate did not decrease through the years with PPC. Conclusion: Different bulking agents may require different injection volumes to achieve the same success rate in endoscopic treatment of vesicoureteral reflux. Habits gained with previous experience using other materials should be revised while using a new agent.

ABSTRACT Context: Polyacrylate-polyalcohol copolymer is a synthetic product, non-biodegradable, with low rate of therapeutic failure and lower incidence of reactions at the site of injection, when compared to biodegradable agents. We report an unprecedent, exuberant and persistent inflammatory reaction following injection of that substance. Patient: a 17 years-old patient with vesico-ureteral reflux and complete pyelocaliceal right duplication was submitted to treatment with polyacrylate-polyalcohol copolymer (STING technique). In the seventh day of post-operatory, she presented intense dysuria and hypogastric pain, without laboratory exams alterations; a symptomatic treatment was started. After two months, the symptoms persisted and an ultrasound detected thickening of bladder wall close to the uretero-vesical junction. After that exam, a cystostopic biopsy showed epithelial hyperplasia with increased edema of lamina propria, suggesting an adverse reaction to the polymer. After four months, there was complete remission, but the reflux persisted with the same grade. Hypothesis: This is an unprecedent reaction following injection of this copolymer. The presence of characteristics such as absence of infection, temporal relation between treatment and beginning of symptoms, and detection of epithelial hyperplasia at the local of injection reinforce the hypothesis of association of the substance and adverse reaction. In that patient, important complains motivated early investigation of urinary tract, that confirmed those aspects. Maybe if that reaction had occurred in patients with lower capacity of expression (such as in infants) it would be unnoticed.

Heavy metals far in excess of trace amounts that are required for healthy plant growth, cause harmful effects on soil microorganisms; however, studies concerning the characterization of microbial communities in mine soils are scarce. The present study is the first attempt to characterize, by means of the analysis of phospholipid fatty acid (PLFA) patterns, soil microbial community composition from a contaminated mine soil (Pb, As) subjected to different remediation technologies. A pot experiment was performed with a soil from the São Domingos mine (South of Portugal) with or without native herbaceous plants combined with the following soil treatments: control; inorganic fertilizer (NPK); inorganic fertilizer plus polyacrylate polymer; inorganic fertilizer plus organic amendment (compost); inorganic fertilizer plus both amendments (compost, polymer). The measurements of PLFA patterns were made on soil samples collected 5 months after the application of remediation treatments. The total microbial biomass and the biomass of specific groups increased notably after soil treatments, particularly those including organic amendments, and were significantly higher in presence of native plants than in the corresponding bare soils. The data also indicated that a plant cover rather than organic and inorganic treatments played the dominant role in determining the composition of the microbial community. An influence of different soil treatments on microbial composition was also observed; the effect of organic amendment being more pronounced than that of the remaining treatments. The results clearly showed the efficacy of a vegetation cover (native plants) combined with the use of organic amendment in the reclamation of this degraded mine soil.

En este trabajo se describe la obtención de nanopartículas de óxido de estaño dopado con cobalto utilizando el método de precipitación controlada. Los polvos sintetizados se utilizaron para conformar barbotinas estables, usando como solvente agua y un 64% en sólidos, adicionándole a la suspensión 5% de tetraetil ortosilicato - TEOS y poliacrilato de amonio - PAA como defloculante. Con esta barbotina, y empleando el método coloidal (slip casting), se obtuvieron piezas en verde que al sinterizarlas a 1250 ºC, durante 2 horas, presentaron una microestructura porosa uniforme y una densidad del 94% de la teórica, al dopar la muestra con un 2% en peso de Co, microestructura muy adecuada si se considera utilizar estas piezas como material activo en dispositivos sensores de gases.

This work describes the obtaining of cobalt-doped tin oxide nanoparticles using the method of controlled precipitation. The synthesized powders were used to form stable slurry, using as solvent water and 64% in solids, adding the suspension 5% ammonium polyacrylate - PAA as a deflocculant and tetraetil ortosilicato - TEOS. With this slip, and using the colloidal method (slip casting), were obtained in green pieces to sintering to 1250 °C, 2 hours, presented a uniform porous microstructure and a 94% of theoretical density, to doping sample with 2% by weight of Co, very suitable microstructure considering these parts used as active material in devices gas sensors.