909 resultados para 091210 Timber Pulp and Paper


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El sector de pasta i paper és considerat un dels set sectors industrials més intensius en consum energètic. La producció i consum d'electricitat i de vapor esdevenen les fonts majoritàries d'emissions de gasos d'efecte hivernacle en aquest sector industrial. Les fàbriques papereres poden assolir objectius de reducció d'emissions mitjançant reducció en origen (substitució de combustibles, introducció d'energies renovables) o bé a partir de mesures d'eficiència energètica en el propi procés. En aquest context, s'ha desenvolupat un mètode de distribució d'emissions que permet assignar a cada unitat d'operació del procés paperer, el seu grau de responsabilitat en emissions. També s'han avaluat diferents mètodes de càlcul de factors d'emissió de vapor i electricitat, tant per plantes de cogeneració com per sistemes individuals. A partir d'aquesta avaluació s'han proposat nous mètodes alternatius als analitzats. Aquests mètodes i els factors d'emissions s'han aplicat a dues fàbriques papereres catalanes.

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La creciente preocupación y concienciación de la sociedad respecto el medio ambiente, y en consecuencia la legislación y regulaciones generadas inducen a la modificación de los procesos productivos existentes en la industria química. Las configuraciones iniciales deben modificarse para conseguir una mayor integración de procesos. Para este fin se han creado y desarrollado diferentes metodologías que deben facilitar la tarea a los responsables del rediseño. El desarrollo de una metodología y herramientas complementarias es el principal objetivo de la investigación aquí presentada, especialmente centrada en el desarrollo y la aplicación de una metodología de optimización de procesos. Esta metodología de optimización se aplica sobre configuraciones de proceso existentes y pretende encontrar nuevas configuraciones viables según los objetivos de optimización fijados. La metodología tiene dos partes diferenciadas: la primera se basa en un simulador de procesos comercial y la segunda es la técnica de optimización propiamente dicha. La metodología se inicia con la elaboración de una simulación convenientemente validada que reproduzca el proceso existente, en este caso una papelera no integrada que produce papel estucado de calidad, para impresión. A continuación la técnica de optimización realiza una búsqueda dentro del dominio de los posibles resultados, en busca de los mejores resultados que satisfazcan plenamente los objetivos planteados. Dicha técnica de optimización está basada en los algoritmos genéticos como herramienta de búsqueda, junto a un subprograma basado en técnicas de programación matemática para el cálculo de resultados. Un número reducido de resultados son finalmente escogidos y utilizados para modificar la simulación existente fijando la redistribución de los flujos del proceso. Los resultados de la simulación del proceso determinan en último caso la viabilidad técnica de cada reconfiguración planteada. En el proceso de optimización, los objetivos están definidos en una función objetivo dentro de la técnica de optimización. Dicha función rige la búsqueda de resultados. La función objetivo puede ser individual o una combinación de objetivos. En el presente caso, la función persigue una minimización del consumo de agua y una minimización de la pérdida de materia prima. La optimización se realiza bajo restricciones para alcanzar este objetivo combinado en forma de una solución de compromiso. Producto de la aplicación de esta metodología se han obtenido resultados interesantes que significan una mejora del cierre de circuitos y un ahorro de materia prima, sin comprometer al mismo tiempo la operabilidad del proceso producto ni la calidad del papel.

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This article describes a prototype system for quantifying bioassays and for exchanging the results of the assays digitally with physicians located off-site. The system uses paper-based microfluidic devices for running multiple assays simultaneously, camera phones or portable scanners for digitizing the intensity of color associated with each colorimetric assay, and established communications infrastructure for transferring the digital information from the assay site to an off-site laboratory for analysis by a trained medical professional; the diagnosis then can be returned directly to the healthcare provider in the field. The microfluidic devices were fabricated in paper using photolithography and were functionalized with reagents for colorimetric assays. The results of the assays were quantified by comparing the intensities of the color developed in each assay with those of calibration curves. An example of this system quantified clinically relevant concentrations of glucose and protein in artificial urine. The combination of patterned paper, a portable method for obtaining digital images, and a method for exchanging results of the assays with off-site diagnosticians offers new opportunities for inexpensive monitoring of health, especially in situations that require physicians to travel to patients (e.g., in the developing world, in emergency management, and during field operations by the military) to obtain diagnostic information that might be obtained more effectively by less valuable personnel.

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The volatiles (VOCs) and semi-volatile organic compounds (SVOCs) responsible for aroma are mainly present in skin of grape varieties. Thus, the present investigation is directed towards the optimisation of a solvent free methodology based on headspace-solid-phase microextraction (HS-SPME) combined with gas chromatography–quadrupole mass spectrometry (GC–qMS) in order to establish the global volatile composition in pulp and skin of Bual and Bastardo Vitis vinifera L. varieties. A deep study on the extraction-influencing parameters was performed, and the best results, expressed as GC peak area, number of identified compounds and reproducibility, were obtained using 4 g of sample homogenised in 5 mL of ultra-pure Milli-Q water in a 20 mL glass vial with addition of 2 g of sodium chloride (NaCl). A divinylbenzene/carboxen/polydimethylsiloxane fibre was selected for extraction at 60 °C for 45 min under continuous stirring at 800 rpm. More than 100 VOCs and SVOCs, including 27 monoterpenoids, 27 sesquiterpenoids, 21 carbonyl compounds, 17 alcohols (from which 2 aromatics), 10 C13 norisoprenoids and 5 acids were identified. The results showed that, for both grape varieties, the levels and number of volatiles in skin were considerably higher than those observed in pulp. According to the data obtained by principal component analysis (PCA), the establishment of the global volatile signature of grape and the relationship between different part of grapes—pulp and skin, may be an useful tool to winemaker decision to define the vinification procedures that improves the organoleptic characteristics of the corresponding wines and consequently contributed to an economic valorization and consumer acceptance.

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Hemicelluloses are polysaccharides of low molecular weight containing 100 to 200 glycosidic residues. In plants, the xylans or the hemicelluloses are situated between the lignin and the collection of cellulose fibers underneath. The xylan is the most common hemicellulosic polysaccharide in cell walls of land plants, comprising a backbone of xylose residues linked by beta-1,4-glycosidic bonds. So, xylanolytic enzymes from microorganism have attracted a great deal of attention in the last decade, particularly because of their biotechnological characteristics in various industrial processes, related to food, feed, ethanol, pulp, and paper industries. A microbial screening of xylanase producer was carried out in Brazilian Cerrado area in Selviria city, Mato Grosso do Sul State, Brazil. About 50 bacterial strains and 15 fungal strains were isolated from soil sample at 35 A degrees C. Between these isolated microorganisms, a bacterium Lysinibacillus sp. and a fungus Neosartorya spinosa as good xylanase producers were identified. Based on identification processes, Lysinibacillus sp. is a new species and the xylanase production by this bacterial genus was not reported yet. Similarly, it has not reported about xylanase production from N. spinosa. The bacterial strain P5B1 identified as Lysinibacillus sp. was cultivated on submerged fermentation using as substrate xylan, wheat bran, corn straw, corncob, and sugar cane bagasse. Corn straw and wheat bran show a good xylanase activity after 72 h of fermentation. A fungus identified as N. spinosa (strain P2D16) was cultivated on solid-state fermentation using as substrate source wheat bran, wheat bran plus sawdust, corn straw, corncob, cassava bran, and sugar cane bagasse. Wheat bran and corncobs show the better xylanase production after 72 h of fermentation. Both crude xylanases were characterized and a bacterial xylanase shows optimum pH for enzyme activity at 6.0, whereas a fungal xylanase has optimum pH at 5.0-5.5. They were stable in the pH range 5.0-10.0 and 5.5-8.5 for bacterial and fungal xylanase, respectively. The optimum temperatures were 55C and 60 A degrees C for bacterial and fungal xylanase, respectively, and they were thermally stable up to 50 A degrees C.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Vegetable oils are important sources of essential fatty acids. It is, therefore, important to characterize plant species that can be used as new oil sources. This study aimed to characterize the oils from guariroba (Syagrus oleracea), jeriva (Syagrus romanzoffiana), and macauba (Acrocomia aculeata). The physicochemical characterization was performed using official analytical methods for oils and fats, free fatty acids, peroxide value, refractive index, iodine value, saponification number, and unsaponifiable matter. The oxidative stability was determined using the Rancimat at 110 degrees C. The fatty acid composition was performed by gas chromatography. The results were submitted to Tukey's test for the medium to 5% using the ESTAT program. The pulp oils were more unsaturated than kernel oils, as evidenced by the higher refractive index and iodine value, especially the macauba pulp oil which gave 1.4556 and 80 g I(2)/100 g, respectively, for these indices. The kernel oils were less altered by oxidative process and had high induction period, free fatty acids below 0.5%, and peroxide value around 0.19 meq/kg. The guariroba kernel oil showed the largest induction period, 91.82 h.

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The motility of Spirillum volutans was used for monitoring the toxicity of effluents of a cellulose and paper industry. Results indicated that there was no correlation between organic content and the toxic effects of the residues in the effluents. The effluents from the chlorination step and from the sludge ponds presented the highest toxicity. on the other hand, the final effluent from the biological treatment basin had no toxic agent. This bioassay showed to be a simple and reliable technique that can be used for adequately monitoring the toxicity of effluents.

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This study was carried out to determine apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of DM, CP, GE, and their respective digestible content of degermed dehulled corn (Zea mays), citrus pulp, and soy (Glycine max) protein concentrate by pigs using the difference method. Thirty-two barrows (28.1 +/- 1.6 kg of BW) were fed a corn-soybean meal basal diet or 1 of 3 diets formulated by replacing 30% of the basal diet with 30% of 1 of the test feedstuffs for 11 d. Chromic oxide (0.3%) was included in the diets. Feces were collected from days 7 to 11 by grab sampling and ileal digesta were collected after pigs were slaughtered on day 12. The AID of DM and AID and ATTD of GE of degermed corn (77.4, 88.7, and 77.7%) were greater (P < 0.05) than those observed in citrus pulp (50.3, 86.5, and 55.8%) and in soy protein concentrate (63.5, 85.1, and 59.4%), which did not differ (P > 0.05). The ATTD of CP, total digestible CP, and total DE of soy protein concentrate (87.5%, 500 g/kg, and 3739 kcal/kg) were higher (P < 0.05) than the values in degermed corn (81.7%, 57.5 g/kg, and 3330 kcal/kg), which were greater (P < 0.05) than those in citrus pulp (60.5%, 39.5 g/kg, and 3223 kcal/kg). Total and ileal digestible DM, AID of CP, and ileal DE of degermed corn (782 g/kg, 673 g/kg, 70.7%, and 2913 kcal/kg) and soy protein concentrate (778 g/kg, 570 g/kg, 78.7%, and 2878 kcal/kg) were similar (P > 0.05) and greater (P < 0.05) than those in citrus pulp (737 g/kg, 436 g/kg, 50.6%, and 2081 kcal/kg). Ileal digestible CP of degermed corn (49.8 g/kg) and citrus pulp (33.0 g/kg) did not differ (P > 0.05) but were smaller (P < 0.05) than the value found in soy protein concentrate (434 g/kg). The DM and energy from degermed corn are more efficiently digested by the pig than those from soy protein concentrate and citrus pulp. Soy protein concentrate was the best protein source evaluated in this study.

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This study aimed to assess the nutritional composition of the fruit and the physicochemical and bioactive properties of jatoba (Hymenaea courbaril L.) pulp and seed oils. The lipid content of both fractions was below 6%. There was a significant presence of minerals, especially, sodium, potassium and phosphorus. The main macronutrient in pulp and seed was crude fiber, and considerable amounts of Vitamin C, 51.87 and 121.45. mg/100. g respectively, were found. The physicochemical properties demonstrated the good quality of the oils. The oxidative stability index was influenced by the composition of fatty acids reaching a value of 45.97. h for the jatoba pulp oil. The most abundant bioactive compounds were α-tocopherol (886.37 and 993.63. mg/kg) and β-sitosterol (61.83 and 91.09. mg/kg) for pulp and seed oils, respectively. Among the unsaturated fatty acids in the pulp, the oleic (46.09%) and linolenic acid (14.54%) stood out. The pulp and seed oils can be considered a valuable source for new industrial, cosmetic and pharmaceutical products. © 2013 Elsevier B.V.