Abstract A study was conducted to record the effect of modified atmospheric packaging (MAP), storage conditions (ambient, zero energy cool chamber and refrigerated) as well as storage period on shelf-life and quality of tomatoes produced through Subhash Palekar natural farming (SPNF) and chemical farming (CHEM) systems. Freshly harvested tomatoes (SPNF and CHEM) packed in LDPE pouches (25.40 μm and 10 pin holes/100 cm2 area) and without packaging were stored under ambient (27±2 °C and 70±2% RH), zero energy cool chamber (ZECC) (17±2 °C and 82 ±2 % RH) and low temperature conditions (10±2 ºC and 90 % RH) for shelf-life studies. The shelf-life comparison was done at every two days’ interval up to 24 days based on physiological loss in weight (PLW) and spoilage percentage. SPNF and CHEM tomatoes were compared on the basis of quality attributes (firmness, acidity, TSS, sugars, total phenols, antioxidant activity etc.), mineral content and sensory characteristics. Results revealed that tomato stored in refrigerated condition had significantly (p ˂0.05) lowest PLW and spoilage incidence and highest sensory acceptability up to 24 days and was at par with ZECC stored tomatoes. Quality evaluation indicated that tomatoes grown under SPNF system contained a higher amount of total solids, total sugars, reducing sugars, ascorbic acid, total phenols and ash. The results showed that tomatoes with MAP and stored under refrigerated storage condition retained maximum quality up to 24 days followed by tomatoes stored under ZECC (18 days) compared to 12 days at ambient conditions. MAP, , (MAP) ambient, (ambient shelflife shelf life (CHEM systems 25.40 2540 25 40 (25.4 1 holes100 holes 100 holes/10 cm area 27±2 272 27 2 (27± C 702 70 70±2 RH, RH (ZECC 17±2 172 17 (17± 8 ± 10±2 102 (10± 9 studies (PLW percentage firmness, firmness (firmness acidity TSS sugars etc., etc etc. etc.) characteristics p ˂0.05 005 0 05 solids acid ash 18 (1 (MAP 25.4 254 4 (25. holes10 holes/1 27± (27 7 70± 17± (17 10± (10 ˂0.0 00 ( 25. (25 holes1 holes/ (2 ˂0. ˂0 ˂

Abstract Eucalyptus sp chips are one of the most important residues or by-products obtained from primary wood processing in the various regions worldwide (12). Its main use is the production of energy (13). When subjected to hydrothermal treatment conditions for the extraction of the hemicelluloses can extract the substances soluble in wáter (17), leaving a solid fraction of cellulose and lignin that will follow other processes of separation and use (11). The waste material used was a mixture of Eucalyptusrostrata, E. grandis and E. Saligna with ages between 12 and 50 years, obtained in one of the sawmills of the region. The sample that was used in the experimental runs comprises the fraction that passes through the 20 mesh and is retained in 80 mesh inside a Zonytest manual sieve. Initially, a factorial design was applied to verify the influence of time (30, 45 and 60 min), temperature (120, 150 and 180 ° C) and liquid / solid ratio (5, 10, 15). This last variable was not significant. Afterwards, an optimization design was applied to the composite centered in the faces, varying the time (20, 30 and 40 min) and temperature (170, 180 and 190 ° C). The treatments were carried out in 200mL digesters in a glycerin bath. The best point obtained was validated with a scale change in a 4.6 L digester, with a heating jacket and a special stirring system. Temperature proved to be the most influential factor in the pretreatment of autohydrolysis of sawdust. The highest extraction of hemicelluloses (89% of initial hemicelluloses) was obtained at 190 ° C and 20 min, however to minimize the generation of furfural by optimizing multiple responses, the best condition was 180 ° C and 20 min. The response surface shows that similar results could be achieved at 170 ° C if the treatment time is extended to 50 min.

Resumen Las astillas de Eucalyptus sp, son uno de los residuos o subproductos más importantes que se obtienen de la transformación primaria de la madera en diversas regiones a nivel mundial (12). Su principal uso es la producción de energía (13). Al ser sometido a condiciones de tratamiento hidrotérmico para la extracción de las hemicelulosas se pueden extraer las sustancias solubles en agua (17), quedando una fracción sólida de celulosa y lignina que seguirán otros procesos de separación y uso (11). El material residual que se utilizó es una mezcla de Eucalyptus rostrata, E. grandis y E. saligna con edades entre los 12 a 50 años, obtenido en uno de los aserraderos de la región. La muestra que se empleó en las corridas experimentales comprende la fracción que pasa por los 20 mesh y queda retenidaen 80 mesh dentro de un tamiz manual Zonytest. Inicialmente se aplicó un diseño factorial para verificar la influencia del tiempo (30, 45 y 60 min), la temperatura (120, 150 y 180°C) y relación líquido/sólido (5, 10, 15). Esta última variable resultó no significativa. Posteriormente se utilizó un diseño de optimización tipo Central Compuesto Centrado en las Caras, variando el tiempo (20, 30 y 40 min) y la temperatura (170, 180 y 190°C). Los tratamientos se realizaron en digestores de 200mL en baño de glicerina. El mejor punto obtenido se validó con un cambio de escala en un digestor de 4.6 L, con una camisa de calefacción y un sistema especial de agitación. La temperatura resultó ser el factor más influyente sobre el pretratamiento de autohidrólisis del aserrín. La mayor extracción de hemicelulosas (89% de las hemicelulosas iniciales) se obtuvo a 190°C y 20 min, sin embargo para minimizar la generación de furfural mediante la optimización de múltiples respuestas, la mejor condición resultó 180°C y 20 min. La superficie de respuesta muestra que podrían alcanzarse resultados similares a 170°C si se prolonga el tiempo de tratamiento a 50 min.

ABSTRACT Phosphorus availability in soils is low due to its strong retention by inner-sphere complexation on minerals in the clay fraction with pH-dependent charges, such as goethite. On the other hand, sulfur has greater availability because it is retained mainly by electrostatic attraction. We evaluated the intensities of the inner-sphere complexation of orthophosphate and sulfate (H2PO4-/HPO42- and SO42- - generically treated as PO4 and SO4) under different experimental conditions (pH, goethite purity, and contact times) on synthetic goethite samples to establish the mechanisms and models involved in those bonds. Inner-sphere PO4 and SO4 were extracted using both HNO3 1 mol L-1 and USEPA 3051A methods. Inner-sphere complexation of PO4 and SO4 was highest at pH 5 in relation to pH 9. Attenuated total reflectance/Fourier transform infrared spectroscopy (ATR-FTIR) spectra showed inner-sphere complexation bands of PO4 on goethite in the protonated binuclear bidentate (pH 5) and deprotonated binuclear bidentate (pH 9) forms. Inner-sphere complexation of PO4 was much more expressive than that of SO4. Phosphorus and sulfur oxyanions displace the diprotonated ferrol ligand (-OH2+0.5 in -FeOH2+0.5), while the -OH-0.5 in the -Fe-OH-0.5 group are only displaced by PO4. The -O-1.5 ligand in Fe-O-1.5 group is not displaced by PO4 or SO4. The high surface negative charge density of PO4 defined its higher activation energy for exchanging -OH2+0.5 and -OH-0.5 on the goethite surface in relation to SO4. The proposed model can be used to reduce inner sphere phosphate adsorption in soils and improve P fertilization efficiency for farming.

Sustainable energy generation has been a growing concern worldwide due to the alarming effects of climate changes in the last few decades. In this scenario, perovskite solar cells hold great promise in contributing for a greener global energy matrix. Despite the great potential of this technology, several difficulties to deploy perovskite solar panels are yet to be overcome, being their long-term stability one of the most critical. In this sense, this work offers an alternative to improve the long-term, operational stability of the devices by passivating the CsFAMA perovskite active layer with a mixture of N-(2-aminoethyl)naphthalimide and mercaptopropionic acid. These modifications improved the perovskite and device stability under ambient conditions. The solar cells without encapsulation and with post-treatment with 5 mM modifier solution retained ca. 90% of its initial power conversion efficiency (PCE) after 500 h exposed to ambient conditions, while standard solar cells retained ca. 58%. Our approach offers a simple new method to improve the stability of perovskite solar cells using an unexplored combination of passivating molecules.

ABSTRACT Intensive application of pesticides in the agricultural sector and for domestic purposes has resulted in increased usage over the years. Pesticides are used to control pest, diseases and weeds in agricultural and urban areas, but their persistence in the environment has resulted in human poisoning, health risk problem and environmental pollution due to their ability to permeate the soil surface, groundwater systems and water surface bodies. Sorption of two organophosphorus pesticides: Diazinon and Clorpyriphos was studied in a soil (S) and in soil modified with clay addition. Soil Alhue, VI region, Chile, was spiked with 1% of either Montmorillonite (M) or Kaolinite (K) (S1). In addition, organic matter (OM), in the soil was eliminated and this soil (S2), was spiked again, with 1% of both clays. Batch sorption and kinetics experiments were conducted to obtain the retained amounts onto the soil samples. Pesticides were quantified by high performance liquid chromatography (HPLC). The results showed that for both pesticides the sorption order is: S1-M > S1-K > S1. For soil without OM (S2) the order is the same, although the adsorption was lower. The adsorption isotherms were expressed by the Langmuir and Freundlich models. The negative Gibb's free energy change (ΔG°) values obtained suggest that the adsorption of both pesticides, is an exothermic process. Clay addition to the soil, increased the adsorption processes, generating an increase in the amount of pesticide retained in the soil and partially avoiding possible contamination of the aquifers. The difference found in relation to the behavior of both clays on the soil, can be explained considering its structure and its octanol-water partition coefficient (kow).

ABSTRACT The aim of this study was to determine the metabolizable energy requirements for maintenance (MEm) and growth (MEg) of llamas and alpacas, by the comparative slaughter technique, at 4200 m above sea level. Twenty male llamas (106.6 ± 7.7 kg live weight, LW) and 20 male alpacas (55.7 ± 4.9 kg LW), both of two years of age, were subdivided into 5 groups of 4 animals each, per species. One group was slaughtered at the beginning of the study to measure the initial body energy content, and the remaining four groups were fed over a period of 55 days on a mixture of chopped hay of oats and Lucerne at four levels of feed (94.2% dry matter, DM): maintenance, intermediate low, intermediate high and ad libitum; corresponding to 40, 50, 60 and 70 g DM/kg LW0.75, respectively. All animals were slaughtered at the end of the experiment to determine retained energy (RE). Another group of four animals per species were used in a parallel in vivo metabolism study to determine the metabolizable energy (ME) content of the diet. Samples of the diet, faeces, and the animal body, were analysed for gross energy contents. The ME content of the diet did not differ between levels if feeding or species, 2226 ± 206 and 2212 ± 165 kcal/kg DM for llamas and alpacas, respectively. The requirements of MEm estimated as heat production at zero RE differed between species (p<0.01): 86.4 and 82.6 kcal/kg LW0.75 for llamas and alpacas, respectively, with corresponding partial efficiencies (km) of 0.77 and 0.66. The requirement of MEg was 9.2 and 11.4 kcal/g LW gain for llamas and alpacas, respectively, with corresponding partial efficiencies (kg) of 0.23 and 0.34. It is concluded that the ME m requirements of llamas and alpacas, at high altitude are independent from each other and about 27% lower than those reported for ruminants.

RESUMEN El objetivo del estudio fue determinar los requerimientos de energía metabolizable de mantenimiento (EMm) y ganancia de peso vivo (EMg) de llamas y alpacas, mediante la técnica de sacrificio comparativo, a 4200 m de altitud. Se utilizaron 20 llamas machos (106.6 ± 7.7 kg de peso vivo, PV) y 20 alpacas machos (55.7 ± 4.9 kg PV), ambos grupos de 2 años de edad, divididos en 5 grupos de 4 animales por especie. Un grupo fue sacrificado al inicio del estudio para medir la energía corporal inicial, mientras que los cuatro grupos restantes fueron alimentados durante 55 días con una mezcla de heno picado de avena y alfalfa, en cuatro niveles de oferta de dieta (94.2% materia seca, MS): mantenimiento, intermedio bajo, intermedio alto y ad libitum; correspondientes a 40, 50, 60 y 70 g MS/kg PV0.75, respectivamente. Todos los animales fueron sacrificados al final del experimento para determinar la retención de energía (RE). Otro grupo de 4 animales por especie acompañó en paralelo con experimentos de metabolismo convencional in vivo, para determinar la energía metabolizable (EM) de la dieta. Las muestras de la dieta, heces y del cuerpo animal se analizaron mediante calorimetría de bomba. El contenido de EM de la dieta fue similar entre niveles de consumo y entre especies, 2226 ± 206 y 2212 ± 165 kcal/kg MS para llamas y alpacas, respectivamente. El requerimiento de EMm, estimado como la producción de calor en retención cero de energía, fue diferente entre especies (p<0.01), 86.4 y 82.6 kcal/kg PV0.75, para llamas y alpacas, respectivamente, con las correspondientes eficiencias parciales (km) de 0.77 y 0.66. El requerimiento de EMg fue 9.2 y 11.4 kcal/g de ganancia de PV, respectivamente, con sus respectivas eficiencias parciales (kg) de 0.23 y 0.34. Se concluye que los requerimientos de EMm de llamas y alpacas en gran altitud son independientes entre sí, y menores en aproximadamente 27% con relación a los reportados para rumiantes.

Abstract A study was carried out to determine the metabolizable energy (ME) and net energy (NE) of corn, wheat by-product, soybean meal, fishmeal, and soybean oil in poultry. 190 male chickens were used, distributed in six experimental diets (basal (B), B + corn (40%), B + wheat by-product (40%), B + soybean meal (30%), B + fish meal (30%), B + soybean oil (10%) with three feeding levels (ad libitum (AL), 85% AL and 70% AL). ME was determined by the total collection method of excreta and NE by the comparative slaughter method, the chickens received the experimental diets from 7 to 21 days of age, the excreta were collected every 24 hours (day 19 to 21). For NE, the energy retained and heat production were determined (7 and 21 days) The ME and NE of corn, wheat by-product, soybean meal, fishmeal and soybean oil was 3734, 2197, 2477, 3289, 8767 kcal / kg DM and 2527, 1598, 1417, 1837, 7550 kcal / kg DM respectively, the NE: ME ratio was higher with soybean oil compared to other feed ingredients.

Resumen Se realizó un estudio para determinar la energía metabolizable (EM) y energía neta (EN) del maíz, subproducto de trigo, harina de soya, harina de pescado y aceite de soya en aves. Se utilizó 190 pollos machos, distribuidos en seis dietas experimentales (basal (B), B + maíz (40%), B + subproducto de trigo (40%), B + harina de soya (30%), B + harina de pescado (30%), B + aceite de soya (10%) con tres niveles de alimentación (ad libitum (AL), 85% AL y 70% AL). La EM se determinó por el método de colección total de excretas y la EN por el método de sacrificio comparativo, los pollos recibieron las dietas experimentales de los siete a 21 días de edad, las excretas se recolectaron cada 24 horas (día 19 al 21). Para EN, se determinó la energía retenida y producción de calor (7 y 21 días). La EM y EN del maíz, subproducto de trigo, harina de soya, harina de pescado y aceite de soya fue de 3734, 2197, 2477, 3289, 8767 kcal/kg MS y 2527, 1598, 1417, 1837, 7550 kcal/kg MS respectivamente, la relación EN:EM fue mayor con el aceite de soya en comparación a los otros insumos.

Abstract: This paper presents a compact, dynamic computable general equilibrium model for the state of Tabasco, México, calibrated to a social accounting matrix for 2003. Two simulations are presented: la reforma studies the impact of the recent energy reform in México with more income from the petroleum production retained and invested in the educational sector. A second simulation, aguas profundas, invests in advanced petroleum technology. La reforma results in greater production, employment, equality and less poverty while aguas profundas generates more skilled employment and attracts more resources, national and international, to the region.

Resumen: Se presenta un modelo dinámico de equilibrio general computable compacto para el estado de Tabasco, México, calibrado a una matriz de contabilidad social del año 2003, agregada en cuatro sectores. Hay dos simulaciones, la reforma, que estudia el impacto de la reciente reforma energética con un mayor ingreso de la producción petrolera retenido e invertido en el sector educacional, la segunda, aguas profundas, invierte en tecnologı́as petroleras avanzadas. La reforma resulta en mayor producción, empleo, igualdad y menor pobreza y aguas profundas genera más empleo calificado y podrı́a atraer mucho mayores recursos nacionales e internacionales a la región.

Shrimp waste meal (SWM) is a by-product from the processing of shrimp for human consumption. The value of SMW in feeding poultry is not well documented. The objective of this study was to determine the energy value and optimal inclusion level of SWM in the diet of growing chickens. A total of 180 one-day-old broilers were randomly assigned to five treatments with 0, 50, 100, 150 and 200 g/kg of SWM included in their diet. There were six replicates of six birds for each treatment. Dry matter intake (DMI) was not affected by the level of SWM that was fed. Retained dry matter varied from 72.39% in the diet that did not contain SWM to 66.97% in the diet with 200 g/kg of SWM. Nitrogen retention (NR) ranged from 54.70% to 70.10%; N ingested was between 18.71% and 24.03%. Energy intake ranged from 73.57% to 69.33% for the control and the diet with 200 g/kg of SWM, respectively. NR improved with increasing SWM inclusion levels. The apparent metabolizable energy (AME) and corrected apparent energy metabolizable (AMEn) ranged from 2928 to 2527 kcal/kg and 2774 to 2329 kcal/kg, respectively, relative to the control and 200 g/kg SWM diets. The energy consumption, in kcal/kg, of SWM consumed was AME = 2332-6.971 x SWM and AMEn = 21138.128 x SWM. High levels of SWM reduce the dry matter metabolization coefficient and metabolizable energy values in broilers during the growing phase, so it is recommended that up to 100 g/kg should be included, which would provide an AMEn of 1300.2 kcal/kg for free-range chickens in dry matter.

Resumo: O aço inoxidável martensítico fundido CA6NM é empregado na construção e reparação de rotores e sua escolha ocorre devido ao custo de fabricação e ao desempenho em operação. Tanto na construção quanto no reparo destes é empregado um metal de solda similar no processo de soldagem, contendo 13% de cromo, 4% de níquel e 0,4% de molibdênio, com teores de carbono inferiores a 0,04%. Por meio do emprego do tratamento térmico de revenimento de duplo estágio, é possível obter melhorias quanto à tenacidade, devido principalmente à formação de austenita retida na microestrutura. O objetivo deste estudo foi avaliar o efeito da temperatura e tempo deste tratamento sobre a microestrutura e tenacidade do metal de solda. Foram analisadas cinco diferentes condições (580 °C/2h, 620 °C/2h, 650 °C/2h, 620 °C/2h+580 °C/4h e 650 °C/2h+580 °C/4h), além de como soldado. Em todas as condições analisadas formou-se austenita retida, porém, os maiores teores foram encontrados nos tratamentos térmicos de duplo estágio. A tenacidade foi avaliada por meio do ensaio Charpy com entalhe em V e os valores de energia absorvida obtidos para o metal de solda apresentaram relação diretamente proporcional à porcentagem de austenita retida encontrada e, para a dureza Vickers, essa relação foi inversa. Tratamentos térmicos com a utilização de mais energia (650 °C/2h+580 °C/4h) levaram a maior formação de austenita retida, enquanto que para o de menor energia (580 °C/2h) foi obtido menor teor austenita retida e menor valor de tenacidade.

Abstract: The cast martensitic stainless steel CA6NM is used in the construction and repair of rotors and its choice occurs due to the cost of manufacture and the performance in operation. Both in the construction and in the repair of these, a similar welding metal is used in the welding process, containing 13% chromium, 4% nickel and 0.4% molybdenum, with carbon contents below 0.04%. Through the use of double-stage tempering heat treatment, it is possible to obtain improvements in toughness, mainly due to the formation of austenite retained in the microstructure. The aim of this study was to evaluate the effect of temperature and time of this treatment on the microstructure and toughness of the weld metal. Five different conditions were analyzed (580 °C/2h, 620 °C/2h, 650 °C/2h, 620 °C/2h+580 °C/4h and 650 °C/2h+580 °C/4h), in addition to of as a soldier. In all conditions analyzed, retained austenite was formed, however, the highest levels were found in double-stage heat treatments. The toughness was evaluated using the V-notch Charpy test and the absorbed energy values obtained for the weld metal showed a relationship directly proportional to the percentage of retained austenite found and, for Vickers hardness, this relationship was inverse. Heat treatments with the use of more energy (650 °C/2h+580 °C/4h) led to a higher formation of retained austenite, while for the lesser energy (580 °C/2h) less retained austenite content was obtained and lowest tenacity value.

Abstract Oil sands surface mining operations in northeastern, Alberta, Canada produce enormous volumes of fluid fine tailings, an aqueous suspension of fine clays, sand, unrecovered bitumen, and diluent hydrocarbons. The tailings are deposited and retained on-site in large settling basins where the colloidal solids sediment and consolidate very slowly by gravity and pore water collects at the surface for re-use. Tailings “biodensification”, mediated by indigenous microbes that produce methane and/or carbon dioxide, is a phenomenon observed in situ and in vitro whereby tailings with active anaerobic microbial communities consolidate and de-water faster than predicted by gravitational (self-weighted) consolidation alone. To exploit this phenomenon, we used organic amendments to stimulate endogenous anaerobic tailings microorganisms. Tailings from three different operators were amended with agri-business by-products, placed in 100-mL microcosms and 1.5-L settling columns, and monitored for methanogenesis, pore water recovery, and solids densification. Several amendments increased methane production and accelerated biodensification compared to unamended and negative controls. Hydrolyzed canola, blood meal, bone meal and glycerol generally accelerated biodensification, stimulated methane production and supported growth of methanogens and fermentative microbes. Amendment altered the chemistry of the tailings, generally decreasing pH, increasing conductivity and magnesium, potassium, sodium, and bicarbonate concentrations. Biodensification is a potential engineered technology for accelerating water recovery and reducing the volume of stored oil sands tailings.

Resumen Introducción: La extracción de hidrocarburos en el Noreste de Alberta, en Canadá, genera una gran cantidad de residuos conocidos como “arenas de alquitrán”. Las arenas de alquitrán son una suspensión acuosa de arcillas finas, arena, betún de petróleo e hidrocarburos. Estos residuos son depositados y retenidos en estanques de sedimentación, donde los sólidos coloidales precipitan y se concentran muy lentamente por efecto de la gravedad y el agua intersticial que se libera se colecta para reúso. La concentración, también llamada densificación, de las arenas de alquitrán mediada por los microorganismos nativos que producen metano o dioxido de carbono, es un fenómeno observado in situ e in vitro, a través del cual, los residuos se precipitan, y se libera agua intersticial más rápidamente que la sedimentación por gravedad. Método: En este trabajo, se aplicaron enmiendas orgánicas para estimular la actividad de microorganismos nativos de los estanques de sedimentación, con el objetivo de acelerar la densificación y liberación de agua intersticial. Se utilizaron muestras de arenas de alquitrán de tres distintas compañías petroleras (Syncrude Canada Ltd.; Suncor Energy Inc.; y Shell Albian Sands), y se enmendaron en condiciones anaeróbicas con seis materias primas de la industria agrícola: (residuos de la extracción de aceite de canola; harina de huesos y harina de sangre de res hidrolizados; suero de leche hidrolizado; glicerol y granos secos de maíz usados para la producción de cerveza y bioetanol). Se utilizó acetato de sodio como control positivo de metanogénesis y 2-bromoetanosulfonato (BES) 10 mM como inhibidor específico de metanogénesis. Los experimentos de densificación se realizaron en botellas serológicas de 100 ml en condiciones anaeróbicas, y en columnas de sedimentación de vidrio de 1.5 L; y se siguió la producción de metano, recuperación de agua intersticial y densificación. Se tomaron muestras durante los experimentos para la cuantificación de bacterias por número más probable, y para el seguimiento de los cambios en la dinámica de comunidades microbianas por pirosecuenciación de los genes ribosolames 16S. Al término de los experimentos de densificación, se realizaron algunas determinaciones de características físicas y químicas de las arenas densificadas y del agua intersticial liberada. Resultados: Varias enmiendas incrementaron la producción de metano y aceleraron la densificación, en comparación con los controles negativo y sin enmienda. Residuos de canola, hidrolizados de harina de hueso, y de sangre y glicerol, aceleraron la densificación, estimularon la producción de metano e incrementaron el crecimiento de microorganismos metanogénicos y fermentadores. Las enmiendas alteraron algunos parámetros químicos de las arenas de alquitrán sedimentadas; generalmente disminuyeron el pH, incrementaron la conductividad eléctrica e incrementaron las concentraciones de magnesio, potasio, sodio y bicarbonato. Discusión o Conclusión: La Densificación mediada por microorganismos representa una tecnología potencial para acelerar los procesos de recuperación de agua intersticial y densificación de las arenas de alquitrán almacenadas en los estanques de precipitación de las industrias petroleras en Canadá.

Resumo Objetivo Avaliamos o efeito da presença de Hovenia dulcis Thunb. (Rhamnaceae) em zonas ripárias sobre a dinâmica da matéria orgânica de pequenos riachos subtropicais. Métodos Realizamos este estudo em três riachos subtropicais de Mata Atlântica com diferentes densidades de H. dulcis na vegetação ripária localizados no sul do Brasil. Em cada riacho quantificamos o aporte de matéria orgânica alóctone durante um ano utilizando baldes (área: 0.04 m2/balde) suspensos a cerca de 1 m do leito dos riachos em três trechos distintos (15 baldes/trecho = 45 baldes/riacho). Mensalmente, o material vegetal retido nos baldes foi recolhido individualmente, seco (40±5 ºC/72 h), identificado (detritos nativos conjuntamente e detritos de H. dulcis isoladamente) e pesado. Resultados Em média, o maior aporte de matéria orgânica nativa ocorreu durante os meses de inverno (~55 g.m-2), tendo oscilado entre ~31 g.m-2 (verão) e ~46 g.m-2 (primavera) ao longo do ano. O aporte de matéria orgânica de H. dulcis, entretanto, foi concentrada nos meses de outono (~56 g.m-2) e verão (~28 g.m-2), sendo escassa nas outras estações do ano (~3 g.m-2 na primavera e no inverno). Apenas a contribuição da matéria orgânica nativa foi associada à precipitação mensal. A presença de H. dulcis alterou a dinâmica da matéria orgânica alóctone nos riachos. Ao contrário do observado com a vegetação nativa (aporte de matéria orgânica relacionada com a pluviosidade) o aporte de H. dulcis esteve relacionado com a fenologia da espécie, que é decídua e com queda foliar fortemente marcada, ocorrendo especialmente durante os meses de outono. Conclusões Quando presente em elevadas densidades (dominante), a presença de H. dulcis na vegetação ripária de riachos torna a oferta de recursos vegetais alóctones escassa em alguns períodos do ano alterando a disponibilidade de energia nesses ecossistemas e, potencialmente, o funcionamento de riachos subtropicais.

Abstract Aim We evaluated the effect of the presence of Hovenia dulcis Thunb. (Rhamnaceae) in riparian zones on the organic matter dynamics of small subtropical streams. Methods We conducted this study in three subtropical Atlantic Forest streams with different densities of H. dulcis in riparian vegetation located in southern Brazil. In each stream, we quantified the input of allochthonous organic matter for one year using buckets (area: 0.04 m2/bucket) suspended about 1 m from the streambed in three different sections (15 buckets/stretch = 45 buckets/stream). Monthly, the plant material retained in the buckets was collected individually, dried (40±5 °C/72 h), identified (native litter together and H. dulcis litter alone) and weighed. Results The largest input of native organic matter occurred during the winter months (~55 g.m-2), ranging from ~31 g.m-2 (summer) to ~46 g.m-2 (spring) over the year. The input of H. dulcis organic matter was concentrated in the autumn (~56 g.m-2) and summer (~28 g.m-2), being scarce in the other seasons (~3 g.m-2 in the spring and winter). Only the contribution of native organic matter was associated with precipitation. Contrary to that observed with native vegetation (input of organic matter related with rainfall), H. dulcis input was related to the phenology of the species, which is deciduous, with leaf fall strongly marked, occurring especially during the autumn. Conclusions When present at high densities (dominant), the presence of H. dulcis in riparian stream vegetation makes the supply of allochthonous plant resources scarce at some periods of the year, altering the energy availability in these ecosystems and, potentially, the functioning of subtropical streams.

Abstract Low birth weight in pigs may compromise lifelong growth potential and productive performance. An evaluation was done of how birth weight affects nitrogen and energy balances in growing pigs. Assays of nitrogen and energy balances were done of five pairs of sibling piglets (n= 10), each pair consisting of a low birth weight (LBW= 912 ± 40 g) and a normal birth weight (NBW= 1,610 ± 223 g) individual. The pigs were managed normally until 90 days of age, then transferred to metabolic cages for the balance assays. These were done when both pigs attained 50 kg weight and again when they were the same age (when the LBW pig weighed 50 kg). The NBW pigs digested more (P<0.05) dry matter at 50 kg and at the same age (86.9 vs 86.0). Nitrogen digestibility tended to be higher (P<0.10) in the NBW at 50 kg (77.6 vs 76.7) and was clearly higher (P<0.05) at the same age (78.0 vs 76.7). Retained nitrogen as a percentage of intake was higher (P<0.01) in the NBW (61.1% vs 57.7 %) at the same age, which also occurred (P <0.10) for nitrogen retained as a percentage of absorbed nitrogen (78.4 % vs 75.2 %). Energy digestibility was higher (P<0.05) in the NBW both at 50 kg (85.1 vs 84.1%) and at the same age (P<0.01) (85.4 vs 84.1 %). Metabolizable energy was higher in the NBW both at 50 kg (P<0.05) (83.0 vs 82.0 %) and at the same age (P<0.01) (83.5 vs 82.0 %). The low birth weight piglets were generally less efficient than the normal birth weight pigs.

Resumen Para determinar el efecto del peso al nacimiento sobre los balances de nitrógeno (N) y energía (E) en cerdos en crecimiento se realizaron balances de N y E a cinco pares de hermanos. Cada par constó de un cerdo de peso bajo al nacimiento (PBN=912 ± 40 g) y un cerdo de peso normal al nacimiento (PNN=1,610 ± 223 g). Los cerdos se manejaron de manera normal hasta los 90 días de edad, cuando se trasladaron a la Unidad Metabólica para realizar los dos estudios de balance: a los 50 kg de peso y a la misma edad (cuando el cerdo PBN pesó 50 kg). Los PNN digirieron más (P<0.05) MS a los 50 kg y a la misma edad (86.9 vs 86.0). La digestibilidad del N tendió (P<0.10) a ser mayor en los PNN a los 50 kg (77.6 vs 76.7) y fue mayor (P<0.05) a la misma edad (78.0 vs 76.7). El N retenido como porcentaje del consumido a la misma edad fue mayor (P<0.01) en los PNN 61.1 % vs 57.7 %; y (P<0.10) en el N retenido como porcentaje del absorbido 78.4 % vs 75.2 %. Se observó una mayor (P<0.05) digestibilidad de la E a los 50 kg en los PNN 85.1 vs 84.1 % y a la misma edad (P<0.01) 85.4 vs 84.1 %. La EM fue mayor a los 50 kg (P<0.05) en los PNN 83.0 vs 82.0 % y a la misma edad (P<0.01) 83.5 vs 82.0 %. Se concluye que los cerdos PBN son menos eficientes que los cerdos PNN.

Resumen Los catalizadores DeNOx se emplean en la eliminación de los óxidos de nitrógeno en vehículos diésel y, también, puede que entren en contacto con carbonilla o incluso sean utilizados como sistemas de reducción de NOx y soot simultáneamente (DPNR-Diesel Particulate NOx Reduction). Por ello, es importante profundizar en el mecanismo de interacción entre el Soot y el catalizador. Se ha utilizado un Soot Printex U modelo y un catalizador Pt-K/Al2O3, con el potasio en forma de óxido e hidroxicarbonato hidratado. Se ha estudiado mediante TG-MS el proceso de eliminación en diferentes atmósferas oxidantes. Los procesos han sido desacoplados mediante el establecimiento de la función de distribución de energía de activación. En ausencia de catalizador, se produce la combustión del carbonilla con el oxígeno molecular en fase gas a temperaturas alrededor de los 1100 K. En presencia de NO, la reducción tiene lugar a menor temperatura debido a su carácter más oxidante y a las especies de óxidos de nitrógeno retenidas y en fase gas. Si la carbonilla se encuentra en contacto con el catalizador Pt-K/Al2O3, los centros Pt-OH-K son los responsables de la eliminación vía gasificación a 780 K con una energía de activación alrededor de 85 kJ mol-1.

Abstract DeNOx catalysts eliminate nitrogen oxides in diesel vehicles and, in addition, can come in contact with soot or, even, be used as Diesel Particulate NOx Reduction (DPNR) material. Therefore, the understanding of the interaction mechanism between soot and catalyst is of high interest. The Printex U model soot and a Pt-K/Al2O3 catalyst have been used, with potassium in the form of oxide and hydrated hydroxycarbonate. The process of elimination in different oxidizing atmospheres has been studied by TG-MS. The processes have been decoupled by establishing the distribution function of activation energy. In the absence of catalyst, the combustion of the soot with the molecular oxygen in the gas phase occurs at temperatures around 1100K. In presence of NO, the reduction takes place at a lower temperature due to its more oxidizing character and the species of nitrogen oxides retained and in the gas phase. If the Soot is in contact with the Pt-K/Al2O3 catalyst, the Pt-OH-K centers are responsible for the elimination via gasification at 780 K with an activation energy around 85 kJ mol-1.

Resumo Os catalisadores do tipo DeNOx eliminam óxidos de nitrogênio em veículos a diesel e, também, podem entrar em contato com partículas ou até mesmo serem usados como sistemas de redução de NOx e carvão simultaneamente (DPNR-Diesel Particulate NOx Reduction); portanto, é importante aprofundar o mecanismo de interação entre a carvão e o catalisador. Carvão modelo Printex U e um catalisador Pt-K/Al2O3 foram utilizados, com potássio na forma de óxido e hidroxicarbonato hidratado. O processo de eliminação em diferentes atmosferas oxidantes foi estudado mediante TG-MS. Os processos foram dissociados, estabelecendo a função de distribuição de energia de ativação. Na ausência de um catalisador, a combustão do carvão com o oxigênio molecular na fase gasosa ocorre a temperaturas em torno de 1100K. Na presença de NO, a redução ocorre a uma temperatura inferior devido ao seu caráter mais oxidante e às espécies de óxidos de nitrogênio retidos e na fase gasosa. Se o carbono estiver em contato com o catalisador Pt-K/Al2O3, os centros de Pt-OH-K são responsáveis pela eliminação via gaseificação a 780 K com uma energia de ativação em torno de 85 kJ mol-1.

Abstract Objective: we found a black precipitate during the infusion of a parenteral nutrition without lipids. The objective of this study is to check the composition of the precipitate and the influence of the type of amino acids in its formation. Methods: four PN bags were prepared with the following composition: 1 l of amino acids solution, 150 g glucose, 60 mEq potassium, 217 mEq chloride, 105 mEq sodium, 15 mEq magnesium, 15 mEq calcium, 18.63 mmol phosphorus and trace elements (Addamel®). Each bag was prepared using a different type of amino acids solution with different amount of cysteine per litre: Tauramin® 10% (0.5 g/l), Primene® 10% (1.89 g/l), Tauramin® 12.6% (0.62 g/l) or Synthamin® 10% (0 g/l). Tauramin® 10% and Primene® 10% were packaged in glass containers whereas Tauramin® 12.6% and Synthamin® 10%, in plastic. The contents of each bag were filtered using Pall NEO96E 0.2 micron filters. A 2.25% area of each filter was observed by scanning electron microscopy at 100x magnification. The analysis by energy dispersive spectroscopy (EDS) was performed at 1,000x magnification. Results: in the Primene® 10% and Tauramin® 10% filters, a greater amount of precipitate was observed than with Tauramin® 12.6% and Synthamin® 10%. The percentage of copper and sulphur in each area of the filters studied was, respectively, 22.9% and 11.5% (Primene® 10%), 19.3% and 9.6% (Tauramin® 10%), 3.7% and 0% (Tauramin® 12.6%), 2.5% y 0% (Synthamin® 10%). Conclusions: the observed precipitate contains copper and sulphur. Precipitate formation occurs in high cysteine content amino acids solutions packaged in glass containers. It is important to use filters in the administration of PN to ensure that this type of precipitates are retained and do not pass to the patient.

Resumen Objetivo: durante la infusión de una nutrición parenteral (NP) sin lípidos se observó un precipitado negro en el filtro. El objetivo del estudio es comprobar la composición del precipitado y la influencia del tipo de aminoácidos en su formación. Métodos: se prepararon cuatro bolsas de NP con 1.000 ml de solución de aminoácidos, 150 g glucosa, 60 mEq potasio, 217 mEq cloruro, 105 mEq sodio, 15 mEq magnesio, 15 mEq calcio, 18,63 mmol fósforo y oligoelementos (Addamel®). Se utilizaron distintos tipos de aminoácidos con concentraciones de cisteína diferentes: Tauramin® 10% (0,5 g/l), Primene® 10% (1,89 g/l), Tauramin® 12,6% (0,62 g/l) o Synthamin® 17 (0 g/l). Tauramin® 10% y Primene® 10% estaban envasados en vidrio y Tauramin® 12,6% y Synthamin® 17, en plástico. El contenido de cada bolsa se filtró utilizando filtros Pall NEO96E de 0,2 micras. Se estudió un área de 2,25% de cada filtro mediante microscopía electrónica de barrido a 100 aumentos. El análisis mediante espectroscopia de dispersión de energía (EDS) se realizó a 1.000 aumentos. Resultados: en los filtros con Primene® 10% y Tauramin® 10%, se observó mayor precipitación que con Tauramin® 12,6% y Synthamin® 10%. El porcentaje de cobre y azufre en cada área de los filtros estudiados fue 22,9% y 11,5% (Primene® 10%), 19,3% y 9,6% (Tauramin® 10%), 3,7% y 0% (Tauramin 12,6%), 2,5% y 0% (Synthamin 10%). Conclusiones: el precipitado observado contiene cobre y azufre. La formación de precipitados se produce con soluciones de aminoácidos envasadas en vidrio, con gran cantidad de cisteína. Es importante usar filtros en la administración de NP para garantizar que los precipitados se retengan y no se pasen al paciente.