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Sample records for chemical pulp

  1. Biological bleaching of chemical pulps.

    PubMed

    Bajpai, Pratima

    2004-01-01

    Use of biotechnology in pulp bleaching has attracted considerable attention and achieved interesting results in recent years. Enzymes of the hemicellulolytic type, particularly xylan-attacking enzymes, xylanases are now used commercially in the mills for pulp treatment and subsequent incorporation into bleach sequences. The aims of the enzymatic treatment depend on the actual mill conditions and may be related to environmental demands, reduction of chemical costs or maintenance or even improvement of product quality. The use of oxidative enzymes from white-rot fungi, that can directly attack lignin, is a second-generation approach, which could produce larger chemical savings than xylanase but has not yet been developed to the full scale. It is being studied in several laboratories in Canada, Japan, the U.S.A. and Europe. Certain white-rot fungi can delignify kraft pulps increasing their brightness and their responsiveness to brightening with chemicals. The fungal treatments are too slow but the enzyme manganese peroxidase and laccase can also delignify pulps and enzymatic processes are likely to be easier to optimize and apply than the fungal treatments. Development work on laccase and manganese peroxidase continues. This article presents an overview of developments in the application of hemicellulase enzymes, lignin-oxidizing enzymes and white-rot fungi in bleaching of chemical pulps. The basic enzymology involved and the present knowledge of the mechanisms of the action of enzymes as well as the practical results and advantages obtained on the laboratory and industrial scale are discussed.

  2. Polyoxometalates in oxidative delignification of chemical pulps: effect on lignin

    Treesearch

    Biljana Bujanovic; Sally Ralph; Richard Reiner; Kolby Hirth; Rajai Atalla

    2010-01-01

    Chemical pulps are produced by chemical delignification of lignocelluloses such as wood or annual non-woody plants. After pulping (e.g., kraft pulping), the remaining lignin is removed by bleaching to produce a high quality, bright paper. The goal of bleaching is to remove lignin from the pulp without a negative effect on the cellulose; for this reason, delignification...

  3. Hexeneuronic acid content of chemical pulp

    Treesearch

    Junyong Zhu; X.S. Chai

    2007-01-01

    This method describes a procedure to determine hexeneuronic acid groups (HexA) in chemical pulps. HexA affects the kappa number determination by reaction with permanganate, and can react with certain bleaching chemicals, e.g. chlorine dioxide and ozone, but not with some others such as oxygen and peroxide. The method is based on the highly selective hydrolysis of HexA...

  4. Polyoxometalates in Oxidative Delignification of Chemical Pulps: Effect on Lignin

    PubMed Central

    Bujanovic, Biljana; Ralph, Sally; Reiner, Richard; Hirth, Kolby; Atalla, Rajai

    2010-01-01

    Chemical pulps are produced by chemical delignification of lignocelluloses such as wood or annual non-woody plants. After pulping (e.g., kraft pulping), the remaining lignin is removed by bleaching to produce a high quality, bright paper. The goal of bleaching is to remove lignin from the pulp without a negative effect on the cellulose; for this reason, delignification should be performed in a highly selective manner. New environmentally-friendly alternatives to conventional chlorine-based bleaching technologies (e.g., oxygen, ozone, or peroxide bleaching) have been suggested or implemented. In an attempt to find inorganic agents that mimic the action of highly selective lignin-degrading enzymes and that can be applicable in industrial conditions, the researchers have focused on polyoxometalates (POMs), used either as regenerable redox reagents (in anaerobic conditions) or as catalysts (in aerobic conditions) of oxidative delignification. The aim of this paper is to review the basic concepts of POM delignification in these two processes.

  5. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE... production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but is not limited...

  6. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD... from the production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but...

  7. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD... from the production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but...

  8. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) THE PULP, PAPER, AND PAPERBOARD... from the production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but...

  9. 40 CFR 430.80 - Applicability; description of the non-wood chemical pulp subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-wood chemical pulp subcategory. 430.80 Section 430.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE... production of pulp and paper at non-wood chemical pulp mills. This subcategory includes, but is not limited...

  10. Fermentation and chemical treatment of pulp and paper mill sludge

    DOEpatents

    Lee, Yoon Y; Wang, Wei; Kang, Li

    2014-12-02

    A method of chemically treating partially de-ashed pulp and/or paper mill sludge to obtain products of value comprising taking a sample of primary sludge from a Kraft paper mill process, partially de-ashing the primary sludge by physical means, and further treating the primary sludge to obtain the products of value, including further treating the resulting sludge and using the resulting sludge as a substrate to produce cellulase in an efficient manner using the resulting sludge as the only carbon source and mixtures of inorganic salts as the primary nitrogen source, and including further treating the resulting sludge and using the resulting sludge to produce ethanol.

  11. Calcium silicate/calcium phosphate biphasic cements for vital pulp therapy: chemical-physical properties and human pulp cells response.

    PubMed

    Gandolfi, M G; Spagnuolo, G; Siboni, F; Procino, A; Rivieccio, V; Pelliccioni, G A; Prati, C; Rengo, S

    2015-11-01

    The aim was to test the properties of experimental calcium silicate/calcium phosphate biphasic cements with hydraulic properties designed for vital pulp therapy as direct pulp cap and pulpotomy. CaSi-αTCP and CaSi-DCDP were tested for ion-releasing ability, solubility, water sorption, porosity, ability to nucleate calcium phosphates, and odontoblastic differentiation—alkaline phosphatase (ALP) and osteocalcin (OCN) upregulation—of primary human dental pulp cells (HDPCs). The materials showed high Ca and OH release, high open pore volume and apparent porosity, and a pronounced ability to nucleate calcium phosphates on their surface. HDPCs treated with CaSi-αTCP showed a strong upregulation of ALP and OCN genes, namely a tenfold increase for OCN and a threefold increase for ALP compared to the control cells. Conversely, CaSi-DCDP induced a pronounced OCN gene upregulation but had no effect on ALP gene regulation. Both cements showed high biointeractivity (release of Ca and OH ions) correlated with their marked ability to nucleate calcium phosphates. CaSi-αTCP cement proved to be a potent inducer of ALP and OCN genes as characteristic markers of mineralization processes normally poorly expressed by HDPCs. Calcium silicate/calcium phosphate cements appear to be attractive new materials for vital pulp therapy as they may provide odontogenic/dentinogenic chemical signals for pulp regeneration and healing, and dentin formation in regenerative endodontics.

  12. POM-assisted electrochemical delignification and bleaching of chemical pulp

    Treesearch

    Helene Laroche; Mohini Sain; Carl Houtman; Claude Daneault

    2001-01-01

    A polyoxometalate-catalyzed electrochemical process has shown good selectivity in delignifying pulp. This breakthrough in redox catalysis shows promise for the development of a new environmentally benign technology for pulp bleaching. The electrochemical process, applied with a mildly alkaline electrolyte solution containing trace amounts of a vanadium-based...

  13. Through drying of paper from mechanical and chemical pulp blends: Transport phenomena behavior

    SciTech Connect

    Hashemi, S.J.; Douglas, W.J.M.

    1999-11-01

    Printing and heavier grades of paper, often made from pulp blends, are dried by a mature process, cylinder drying, which has a much lower drying rate than through air drying. Analysis of the possible extension of through drying to such semipermeable sheets requires knowledge of the basic characteristics of this process when applied to such grades. Both momentum transport and drying rate aspects of transport phenomena in through air drying were investigated for sheets made from mechanical pulp--chemical pulp blends. The first determination of air permeability for moist paper from TMP and blends of TMP and kraft pulp is reported. The porosity, bulk and specific surface of paper from such blends are also reported. For paper from such blends the mechanical pulp exerts a disproportionate influence through control of the macrostructure by the stiff mechanical pulp fibers and control of the microstructure by its high fines content. Changes in sheet structure affect the momentum transport sensitively but the heat and mass transfer behavior determining drying rate is much less affected. Progress was made on the fundamental Re-{integral}-d{sub p} basis of analysis of through drying. The highly nonlinear dependence of momentum transport properties on pulp blend composition and on moisture content was related to the corresponding changes in the macro-and micro-pore structure available for air through flow.

  14. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... operator of each pulping system using a semi-chemical or soda process subject to the requirements of...

  15. Steam system opportunity assessment for the pulp and paper, chemical manufacturing, and petroleum refining industries: Main report

    SciTech Connect

    None, None

    2002-10-01

    This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

  16. Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report

    SciTech Connect

    Not Available

    2002-10-01

    This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

  17. Microstructural and chemical effects of wet/dry cycling on pulp fiber-cement composites

    SciTech Connect

    Mohr, B.J. . E-mail: bmohr@tntech.edu; Biernacki, J.J.; Kurtis, K.E.

    2006-07-15

    The microstructural and chemical mechanisms responsible for pulp fiber-cement composite degradation during wet/dry cycling are being investigated through environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), and mechanical testing. Based on these results, a three-part progressive degradation mechanism for cast-in-place kraft pulp fiber-cement composites is proposed, which involves: (1) initial fiber-cement or fiber interlayer debonding (2) reprecipitation of needle-like or sheath-like ettringite within the void space at the former fiber-cement interface or between the S1 and S2 fiber layers, and (3) fiber mineralization due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. This investigation also revealed that kraft pulp fibers exhibit poor resistance to degradation due to their inferior dimensional stability, as compared to thermomechanical pulp (TMP) fibers. TMP fibers contain significant amounts of lignin, which is alkali sensitive. Despite this, TMP fiber-cement composite exhibit improved resistance to degradation during wet/dry cycling. It is proposed that this improvement in durability may be attributed to the presence of lignin in the cell wall restricting fiber dimensional changes during wetting and drying, and hence, minimizing fiber-cement debonding. Additionally, it is proposed that lignin acts as physical barrier to calcium hydroxide formation within the fiber cell wall, minimizing fiber mineralization of TMP fibers.

  18. [Chemical characteristics of the pulp and oil of the annona tree (Annona coriaceae)].

    PubMed

    Agostini, T da S; Cecchi, H M; Barrera-Arellano, D

    1995-09-01

    Belonging to the Annonaceae family, marolo (Annona coriaceae) is a native species of the Brazilian "cerrado" región (Minas Gerais, Goiás and Distrito Federal) and can be found in South American tropical zones. Its fruits are highly consumed by local people and commercialized in markets or street stalls. There is, however, a tendency for the extinction of marolo due to deforestation and the large scale plantation of monocultures instead of native plants. The literature still offers no data on the chemical composition of the proximate composition and vitamin C, A and tannin contents were carried out on the yellow marolo pulp as well as the determination of the physico-chemical characteristics of the seed oil. Five batches of fruit from the Alfenas region--south of Minas Gerais State--were analysed in this work and their average composition were: humidity 77%, total sugar 15%, reducing sugar 11%, crude protein 1%, lipids 3%, fiber 5% and fixed mineral residue 1%. The contents of vitamin C and A were 8.2 mg/100g and 117.5 RE/100g, respectively, and the tannin content was 245 mg/100g. The results showed high fiber and lipid contents of marolo pulp in comparison with many other tropical fruit pulps. The vitamin C contents were equivalent to those found in avocado, pineapple and watermelon, while the vitamin A contents were equivalent to papaya, peach, guava and several other tropical fruits. Marolo seed contains 45% of oil on a dry basis. Its composition and physico-chemical characteristics showed the possibility of producing a good quality oil, with great potential for the fine oil market. However the presence of alkaloids in the oil needs to be further studied. Their elimination could be done by refining or extraction in a continuous press. The results exalt the high quality of marolo pulp, showing that the preservation of native species should be stimulated.

  19. New alternative energy pathway for chemical pulp mills: From traditional fibers to methane production.

    PubMed

    Rodriguez-Chiang, Lourdes; Vanhatalo, Kari; Llorca, Jordi; Dahl, Olli

    2017-07-01

    Chemical pulp mills have a need to diversify their end-product portfolio due to the current changing bio-economy. In this study, the methane potential of brown, oxygen delignified and bleached pulp were evaluated in order to assess the potential of converting traditional fibers; as well as microcrystalline cellulose and filtrates; to energy. Results showed that high yields (380mL CH4/gVS) were achieved with bleached fibers which correlates with the lower presence of lignin. Filtrates from the hydrolysis process on the other hand, had the lowest yields (253mL CH4/gVS) due to the high amount of acid and lignin compounds that cause inhibition. Overall, substrates had a biodegradability above 50% which demonstrates that they can be subjected to efficient anaerobic digestion. An energy and cost estimation showed that the energy produced can be translated into a significant profit and that methane production can be a promising new alternative option for chemical pulp mills. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Coagulation of wood extractives in chemical pulp bleaching filtrate by cationic polyelectrolytes.

    PubMed

    Leiviskä, T; Rämö, J

    2008-05-01

    The purpose of this research was to investigate the effectiveness of short-chain cationic polyelectrolytes of different molecular weights and charge densities in reducing turbidity and selectively removing toxic wood extractives from chemical birch pulp filtrate. The effects of chemical type, dosage and temperature were of interest. An effective performance was achieved with a copolymer of acrylamide and methacrylate of medium molecular weight and medium charge density at 72 degrees C and pH 5-6. The dosage range optimum for reducing the turbidity was 102-142 mg/L. Up to 92% of the wood extractives was selectively removed.

  1. Removal of persistent bioaccumulative toxic chemicals from pulp and paper mill effluent streams

    SciTech Connect

    Holm, S.E.

    1995-12-31

    Several organizations have called for the reduction of PBTs or Persistent Bioaccumulative Toxics because of this class of chemicals potential environmental consequences when released into the environment. PBTs are persistent because of their resistance to biological contamination, because they bioaccumulate in the fatty tissue of organisms, and are toxic to aquatic species at relatively low levels. PBTs may be produced commercially such as for use as a pesticide or herbicide or inadvertently as byproducts, such as from diesel engines, incinerators, and during pulp bleaching using chlorine or chlorine derivatives. This paper will show how the pulp and paper industry has utilized the pollution prevention technique of process change to remove the levels of PBTs from its waste stream and how this process change relates to decreasing levels of specific PBTs in the environment. Chlorinated phenolic compounds and dioxin will be used as examples.

  2. Nanoscale chemical surface characterization of four different types of dental pulp-capping materials.

    PubMed

    Gong, Victor; França, Rodrigo

    2017-03-01

    The surface of any dental pulp-capping material has important implications for its clinical success because it is in direct contact with dental tissue, which influences its cytotoxicity. The aim was to determine the chemical composition of the first atomic layers of four pulp-protection agents because these atoms can initiate the pulp healing process. Biodentine (Septodont), ProRoot MTA (Dentsply), Dycal (Caulk) and TheraCal (Bisco) were prepared (n=5) according to manufacturer recommendations. The chemical surface composition was analyzed using X-ray photoelectron spectroscopy (XPS), and the bulk composition was analyzed by Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX). Both survey and high resolution XPS spectra of the elements detected were obtained, with element-dependent probe depths of 4-5nm; the binding energy scale was normalized to the C1s adventitious carbon peak at 285eV. There was a significant difference between bulk and surface compositions for all the pulp-capping materials. The calcium surface concentrations at 0nm and 70nm were Dycal 7.9% and 15.1%; ProRoot MTA 14.1% and 17%; TheraCal 0% and 3.6%; and Biodentine 17.6% and 33.7%, respectively. Trace amounts of the following elements (<1%) were also found: Ti, S and Zr in Biodentine; Bi in ProRoot MTA and TheraCal; Na, P, Zn and N in Dycal. The XPS results showed that Ca in the surface layer could vary from 0 to 18%, depending on the material. Aliphatic carbons, from the polymerization reactions, especially in Dycal and TheraCal, were found to mask the other components. This study compares, for the first time, the chemical composition of the first atomic layers of four pulp-capping materials. This information is relevant because the interaction between pulpar cells and the material's outermost atomic layer is an important factor for leading the pulpal response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Alkaline peroxide pulping of oil palm empty fruit bunch by variation of chemical strength

    NASA Astrophysics Data System (ADS)

    Dermawan, Yunita Megasari; Ghazali, Arniza; Daud, Wan Rosli Wan; Lazin, Mohd Azli Khairil Mat

    2012-09-01

    Papers produced from oil palm empty fruit bunches (EFB) via Alkaline Peroxide Pulping (APP) was preceded by three main steps; dewaxing of EFB, alkaline peroxide (AP) impregnation into EFB and refining of biomass to generate pulp. The experiment was carried by varying chemical level and number of impregnation stages. For 2:2.5% AP level, two-stage impregnation improved hand sheets tear index by 45%, 164% boost in tensile index, 26% enhancement in zero span index and more than 5% in burst index. By applying 8:10% AP level, significant improvements were gained at the third and fourth stages of AP impregnation. Although there was no significant change in hand sheet strength with multiple impregnation for 4:5% AP level, improvement in brightness of hand sheets was apparent, analogous to the effect of increasing AP level. The found paper properties development show that alkaline peroxide pulping of EFB could be adapted to various targeted properties by adjustment of AP level and impregnation stages.

  4. Identification of the need for research on chemical tracers to detect pulp mill effluent exposure

    SciTech Connect

    Ali, N.; Humphrey, S.; Van Coillie, R.

    1995-12-31

    A critical factor in the assessment of the effects of effluent exposure on sampled biota is the verification of exposure in nearfield and farfield zones and verification of the lack of exposure in the reference areas. At mills with rapid dilution of effluent, or where physical barriers to fish movement between exposure and reference areas do not exist, an appropriate fish tracer must be used. In Canada, because of multiple industrial and municipal discharges at certain pulp mill sites, it is difficult to assess the effects of the mill effluent in isolation from those of neighboring influences unless tracers specific to the different effluents are used. Examples of substances proposed as tracers for pulp mill effluent include resin acids, chloroguaiacols, chlorophenols, dioxin, and furan congeners. This paper gives a summary of tracer substances used to date and the problems encountered in selecting and measuring suitable chemical tracers for regulated environmental effects monitoring studies at Canadian mills. Based on their experience, there is urgent need for research into appropriate tracer substances for pulp mill as well as other industrial and municipal effluents.

  5. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... in paragraphs (c) and (d) of this section. (1) At existing affected sources, the total HAP...

  6. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... kraft, soda, and semi-chemical processes. 63.443 Section 63.443 Protection of Environment ENVIRONMENTAL... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a... in paragraphs (c) and (d) of this section. (1) At existing affected sources, the total HAP...

  7. Chemometrics-assisted spectrophotometry method for the determination of chemical oxygen demand in pulping effluent.

    PubMed

    Chen, Honglei; Chen, Yuancai; Zhan, Huaiyu; Fu, Shiyu

    2011-04-01

    A new method has been developed for the determination of chemical oxygen demand (COD) in pulping effluent using chemometrics-assisted spectrophotometry. Two calibration models were established by inducing UV-visible spectroscopy (model 1) and derivative spectroscopy (model 2), combined with the chemometrics software Smica-P. Correlation coefficients of the two models are 0.9954 (model 1) and 0.9963 (model 2) when COD of samples is in the range of 0 to 405 mg/L. Sensitivities of the two models are 0.0061 (model 1) and 0.0056 (model 2) and method detection limits are 2.02-2.45 mg/L (model 1) and 2.13-2.51 mg/L (model 2). Validation experiment showed that the average standard deviation of model 2 was 1.11 and that of model 1 was 1.54. Similarly, average relative error of model 2 (4.25%) was lower than model 1 (5.00%), which indicated that the predictability of model 2 was better than that of model 1. Chemometrics-assisted spectrophotometry method did not need chemical reagents and digestion which were required in the conventional methods, and the testing time of the new method was significantly shorter than the conventional ones. The proposed method can be used to measure COD in pulping effluent as an environmentally friendly approach with satisfactory results.

  8. A comparative evaluation of explosion hazards in chemical and mechanical pulp bleaching systems

    Treesearch

    P.W. Hart; Alan Rudie

    2010-01-01

    Three pulp mills in North America using 50% hydrogen peroxide have suffered explosions of pumps, mixers, and tanks. In two instances, alkali-catalyzed decomposition of peroxide is implicated in the explosion. Although many mechanical pulping facilities use hydrogen peroxide to bleach pulp, no &-catalyzed explosions have been reported. This research uses a kinetic...

  9. Chemical composition and antioxidant capacity of açaí (Euterpe oleracea) genotypes and commercial pulps.

    PubMed

    Carvalho, Ana Vânia; Ferreira Ferreira da Silveira, Tayse; Mattietto, Rafaella de Andrade; Padilha de Oliveira, Maria do Socorro; Godoy, Helena Teixeira

    2017-03-01

    Açaí has been reported to contain many bioactive compounds, including phenolic compounds such as anthocyanins. This study aimed to determine the chemical composition and antioxidant potential of pulps of three different açaí genotypes from the Active Germplasm Bank of Embrapa Eastern Amazon and three commercial açaí pulps from Belém, state of Pará, Brazil. Anthocyanin 3-rutinoside was the major anthocyanin present in freeze-dried açaí pulp samples. The commercial sample C showed the greatest amounts of cyanidin 3-glucoside and cyanidin 3-rutinoside (18 942 and 34 397 µg g(-1) respectively). The content of phenolic compounds varied significantly among the commercial and genotype samples, and vanillic acid was found in the highest concentration in the samples studied. All açaí samples showed high DPPH, ORAC and TEAC values, confirming the exceptionally high radical-scavenging capacity of açaí pulp previously reported by other researchers. The commercial samples showed higher antioxidant capacity and higher levels of anthocyanins and non-anthocyanic compounds than those of the genotype samples. Among the genotypes studied, L4P16 stood out for its higher contents of fibre and bioactive compounds and higher antioxidant capacity, indicating that this genotype has great potential for use in plant breeding programs that should be further explored. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Chemical composition and protein enrichment of orange peels and sugar beet pulp after fermentation by two Trichoderma species.

    PubMed

    Ahmadi, F; Zamiri, M J; Khorvash, M; Banihashemi, Z; Bayat, A R

    2015-01-01

    The present experiment aimed at increasing orange peel and sugar beet pulp protein content through solid-state fermentation by Trichoderma reesei and Trichoderma viride. In vitro digestibility and changes in the chemical composition of the fermented products were determined after seven days of fungal cultivation using gas production tests. The cultivation of T. reesei and T. viride on orange peels decreased neutral detergent soluble content (P<0.01) and increased cellulose, hemicellulose and lignin contents (P<0.01). Changes in fiber fractions were found to be more pronounced with T. viride. The cultivation of T. reesei and T. viride on sugar beet pulp increased neutral detergent soluble content (P<0.01) and decreased cellulose and hemicellulose contents (P<0.01). These changes were more pronounced with T. reesei. The cultivation of T. reesei or T. viride on orange peels or sugar beet pulp increased crude protein content (P<0.01) compared with the unfermented materials; however, the increase was more pronounced for orange peels fermented with T. viride when corrected for weight loss (P<0.05). After 24 and 48 h of incubation, significant decreases in cumulative gas production (P<0.01) were observed in fermented sugar beet pulp and orange peels compared with the unfermented materials. Fungal treatment of orange peels and sugar beet pulp reduced the digestibility of in vitro organic matter, metabolizable energy and average fermentation and gas production rates (P<0.01). The data showed that seven days of solid-state fermentation of orange peels and sugar beet pulp by T. reesei or T. viride can increase their crude protein content.

  11. Determination of physical characteristics, chemical composition and digestion coefficients of treated lemon pulp with Saccharomyces cerevisiae in goat diet.

    PubMed

    Dadvar, P; Dayani, O; Mehdipour, M; Morovat, M

    2015-02-01

    The aim of this study was to evaluate the effects of processing of lemon pulp with Saccharomyces cerevisiae on physical properties, chemical composition, digestion coefficients and blood parameters. Eight adult male Raeini goats were used in a 28-day period. The experimental design was a completely randomised design with two treatments and four replicates. The first 21 days were for adaptation, and the last 7 days were for collecting samples. The animals were housed in individual metabolic cages equipped with a urine-faeces separator and were fed with diet containing alfalfa hay (60%) and lemon pulp (40%) at the maintenance level. Collected data were subjected to analysis of completely randomised design. With diet containing processed lemon pulp, functional specific gravity, bulk density, soluble dry matter, percentage of crude protein, neutral detergent fibre (NDF), acid detergent fibre and crude ash were significantly increased and water-holding capacity, insoluble dry matter, insoluble ash percentage of dry matter, organic matter, crude fat, non-fibrous carbohydrates and nitrogen-free extract were significantly decreased (p < 0.05). Digestion coefficient of organic matter in dry matter and metabolisable energy were also decreased in treated lemon pulp (p < 0.05). Compared with untreated lemon pulp, digestibility of crude protein and NDF was higher (p < 0.05), but digestibility of crude fat was lower (p < 0.05). In general, processing of lemon pulp with S. cerevisiae improved the physical characteristics and increased the percentage of crude protein and the digestion coefficients of protein and NDF. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  12. Chemical composition and protein enrichment of orange peels and sugar beet pulp after fermentation by two Trichoderma species

    PubMed Central

    Ahmadi, F; Zamiri, M. J.; Khorvash, M; Banihashemi, Z; Bayat, A. R.

    2015-01-01

    The present experiment aimed at increasing orange peel and sugar beet pulp protein content through solid-state fermentation by Trichoderma reesei and Trichoderma viride. In vitro digestibility and changes in the chemical composition of the fermented products were determined after seven days of fungal cultivation using gas production tests. The cultivation of T. reesei and T. viride on orange peels decreased neutral detergent soluble content (P<0.01) and increased cellulose, hemicellulose and lignin contents (P<0.01). Changes in fiber fractions were found to be more pronounced with T. viride. The cultivation of T. reesei and T. viride on sugar beet pulp increased neutral detergent soluble content (P<0.01) and decreased cellulose and hemicellulose contents (P<0.01). These changes were more pronounced with T. reesei. The cultivation of T. reesei or T. viride on orange peels or sugar beet pulp increased crude protein content (P<0.01) compared with the unfermented materials; however, the increase was more pronounced for orange peels fermented with T. viride when corrected for weight loss (P<0.05). After 24 and 48 h of incubation, significant decreases in cumulative gas production (P<0.01) were observed in fermented sugar beet pulp and orange peels compared with the unfermented materials. Fungal treatment of orange peels and sugar beet pulp reduced the digestibility of in vitro organic matter, metabolizable energy and average fermentation and gas production rates (P<0.01). The data showed that seven days of solid-state fermentation of orange peels and sugar beet pulp by T. reesei or T. viride can increase their crude protein content. PMID:27175146

  13. Green chemicals from pulp production black liquor by partial wet oxidation.

    PubMed

    Muddassar, Hassan Raja; Melin, Kristian; de Villalba Kokkonen, Daniela; Riera, Gerard Viader; Golam, Sarwar; Koskinen, Jukka

    2015-11-01

    To reduce greenhouse gas emissions, more sustainable sources of energy, fuel and chemicals are needed. Biomass side streams such as black liquor, which is a by-product of pulp production, has the potential to be used for this purpose. The aim of the study was the production of carboxylic acids, such as lactic acid, formic acid and acetic acid, from kraft and non-wood black liquor. The processes studied were partial wet oxidation (PWO) and catalytic partial wet oxidation (CPWO). The results show that the yield of carboxylic acid is higher when treated by PWO than the results from CPWO at temperatures of 170 °C and 230 °C. The results shows that the PWO process can increase the yield of carboxylic acids and hydroxy acids in black liquor, reduce lignin content and decrease pH, which makes further separation of the acids more favourable. The hydroxy acids are valuable raw materials for biopolymers, and acetic acid and formic acid are commonly used chemicals conventionally produced from fossil feedstock. © The Author(s) 2015.

  14. 40 CFR 63.443 - Standards for the pulping system at kraft, soda, and semi-chemical processes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... operated at a minimum temperature of 871 °C (1600 °F) and a minimum residence time of 0.75 seconds; or (4... Paper Industry § 63.443 Standards for the pulping system at kraft, soda, and semi-chemical processes. (a...)(ii)(C) of this section. (A) Each knotter system with emissions of 0.05 kilograms or more of total...

  15. Pollution control in pulp and paper industrial effluents using integrated chemical-biological treatment sequences.

    PubMed

    El-Bestawy, Ebtesam; El-Sokkary, Ibrahim; Hussein, Hany; Keela, Alaa Farouk Abu

    2008-11-01

    The main objective of the present study was to improve the quality of pulp and paper industrial wastewater of two local mills RAKTA and El-Ahlia, Alexandria, Egypt, and to bring their pollutant contents to safe discharge levels. Quality improvement was carried out using integrated chemical and biological treatment approaches after their optimization. Chemical treatment (alum, lime, and ferric chloride) was followed by oxidation using hydrogen peroxide and finally biological treatment using activated sludge (90 min for RAKTA and 60 min for El-Ahlia effluents). Chemical coagulation produced low-quality effluents, while pH adjustment during coagulation treatment did not enhance the quality of the effluents. Maximum removal of the tested pollutants was achieved using the integrated treatment and the pollutants recorded residual concentrations (RCs) of 34.67, 17.33, 0.13, and 0.43 mg/l and 15.0, 11.0, 0.0, and 0.13 mg/l for chemical oxygen demand (COD), biochemical oxygen demand (BOD5), tannin and lignin, and silica in RAKTA and El-Ahlia effluents, respectively, all of which were below their maximum permissible limits (MPLs) for the safe discharge into water courses. Specific oxygen uptake rate (SOUR) and sludge volume index (SVI) values reflect good conditions and healthy activated sludge. Based on the previous results, optimized conditions were applied as bench scale on the raw effluents of RAKTA and El-Ahlia via the batch chemical and the biological treatment sequences proposed. For RAKTA effluents, the sequence was as follows: (1) coagulation with 375 mg/l FeCl3, (2) oxidation with 50 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial concentration and 90 min hydraulic retention time (HRT), while for El-Ahlia raw effluents, the sequence was (1) coagulation with 250 mg/l FeCl3, (2) oxidation with 45 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial concentration and 60

  16. A new technique for screening chemical toxicity to the pulp from dental restorative materials and procedures.

    PubMed

    Hume, W R

    1985-11-01

    An in vitro test system is described which allows for quick and relatively inexpensive examination of the potential for chemical toxicity to the pulp of materials and procedures used in the restoration of single teeth. The test system consisted of two sequential steps. First, a restorative procedure was carried out on a freshly-extracted human tooth crown, to the pulpal surface of which had been attached a chamber filled with sterile tissue-culture medium. The preparation was kept at 37 degrees C. The culture medium was removed at day one and replaced with fresh medium, which was removed at day 3. In the second step, we used a standard tissue-culture toxicity assessment technique to examine both culture medium samples for the presence of chemical toxins. In use, this system gave results which correlated well with the known clinical potential for pulpal toxicity of various dental materials and techniques. For example, zinc oxide-eugenol used as temporary filling or base had no apparent potential for toxicity. Sealing a cotton pellet containing phenol into a cavity was of high apparent potential toxicity. Acrylic resin as intracoronal or extracoronal fillings showed potential for toxicity; this potential was decreased by lining with calcium hydroxide cement. Composite resin placed onto etched dentin had apparent toxic potential, but had less such potential when placed onto unetched dentin. The technique had some advantages over previously described in vitro toxicity test for restorative materials, because it included a step requiring diffusion of potential toxins into and through human dentin, and because it allowed for examination of variations in technique which mimic clinical behavior, and of materials used in sequence or in combination.

  17. Thermal Processing Alters the Chemical Quality and Sensory Characteristics of Sweetsop (Annona squamosa L.) and Soursop (Annona muricata L.) Pulp and Nectar.

    PubMed

    Baskaran, Revathy; Ravi, Ramasamy; Rajarathnam, Somasundaram

    2016-01-01

    The objective of this study was to investigate the effect of thermal processing on the chemical quality and sensory characteristics of Annona squamosa L. and Annona muricata L. fruit pulps and nectar. The fruit pulps were pasteurized at 85 °C for 20 min and nectar prepared as per Food Safety and Standards Authority of India (FSSAI) specifications. The chemical composition of fresh and heated pulps of A. squamosa and A. muricata showed that compared to fresh, the chemical profile and sensory profile changed in heated samples and nectar. The free and bound phenolics of A. squamosa increased in heated pulp (127.61 to 217.22 mg/100 g and 150.34 to 239.74 mg/100 g, respectively), while in A. muricata, free phenolics increased very marginally from 31.73 to 33.74 mg/100 g and bound phenolics decreased from 111.11 to 86.91 mg/100 g. This increase in phenolic content may be attributed to the perception of bitterness and astringency in A. squamosa pulp on heating. In electronic tongue studies, principal component analysis (PCA) confirmed that the fresh and heated pulps had different scores, as indicated by sensory analysis using qualitative descriptive analysis (QDA). E-tongue analysis of samples discriminated the volatile compounds released from the heated A. squamosa and A. muricata fruit pulps and nectar in their respective PCA plots by forming different clusters.

  18. Lignin from rice straw Kraft pulping: effects on soil aggregation and chemical properties.

    PubMed

    Xiao, C; Bolton, R; Pan, W L

    2007-05-01

    Lignin contained in pulping liquor that is generated during the pulping process for papermaking is a disposal problem for the pulp and paper industry. Separating lignin and other organic components from pulping liquor with inorganic acids may improve its applicability to fields as a beneficial soil amendment while offering a potential disposal alternative. Sulfuric acid-precipitated lignin from rice straw pulping liquor applied at rates of 1.67 and 3.34 g C kg(-1) soil was incubated to evaluate its effects on soil properties over 8 weeks of incubation. Addition of this acid-precipitated lignin at these rates decreased soil pH by 0.24-0.53 units over 8 weeks of incubation, suggesting that this sulfuric acid-precipitated lignin from pulping liquor may have potential as a soil acidifying agent. Soil electrical conductivity (EC) only increased by up to 0.36 d Sm(-1), but highest EC levels were less than 4 d Sm(-1), indicating that lignin applied at both rates would not cause salinity problems. Application of this lignin increased soil organic C by 1.46 and 3.13 g C kg(-1), and total soil N by 0.07 and 0.17 g N kg(-1) over the incubation period. Lignin improved the macroaggregation of >2mm size fraction, and increased wet microaggregate stability of >2mm and 0.5-0.25 mm aggregates compared to a nonamended control. The results of this study suggest that this acid-precipitated lignin from pulping liquor may have potential as a beneficial soil amendment.

  19. Chemical composition of abaca (Musa textilis) leaf fibers used for manufacturing of high quality paper pulps.

    PubMed

    del Río, José C; Gutiérrez, Ana

    2006-06-28

    The chemical composition of leaf fibers of abaca (Musa textilis), which are commonly used for high-quality paper pulp production, was thoroughly studied. The results revealed that the lignin content was 13.2% of the total fiber. The analysis of abaca fibers by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS) released predominantly compounds arising from lignin and p-hydroxycinnamic acids, with high amounts of 4-vinylphenol. The latter compound was demonstrated to arise from p-coumaric acid by pyrolysis of abaca fibers in the presence of tetramethylammonium hydroxide, which released high amounts of p-coumaric acid (as the methyl derivative). Products from p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) propanoid units, with a predominance of the latter (H:G:S molar ratio of 1.5:1:4.9), were also released after Py-GC/MS of abaca fibers. Sinapyl and coniferyl acetates, which are thought to be lignin monomer precursors, were also found in abaca. The extractives content of the abaca fiber (0.4%) was low, and the most predominant compounds were free sterols (24% of total extract) and fatty acids (24% of total extract). Additionally, significant amounts of steroid ketones (10%), triglycerides (6%), omega-hydroxyfatty acids (6%), monoglycerides (4%), fatty alcohols (4%), and a series of p-hydroxycinnamyl (p-coumaric and ferulic acids) esterified with long chain alcohols and omega-hydroxyfatty acids were also found, together with minor amounts of steroid hydrocarbons, diglycerides, alpha-hydroxyfatty acids, sterol esters, and sterol glycosides.

  20. An HPLC method for the quantitative determination of hexeneuronic acid groups in chemical pulps.

    PubMed

    Gellerstedt, G; Li, J

    1996-11-20

    It has recently been demonstrated that 4-deoxy-L-threo-hex-4-enopyranosyluronic acid ("hexeneuronic acid") is present in kraft pulps and linked to the xylan backbone. An analytical method for the quantitative determination of hexeneuronic acid groups has now been developed. The procedure involves a selective hydrolysis with mercuric acetate of the glucosidic linkage between the hexeneuronic acid group and the xylan chain, followed by oxidation with periodate to form beta-formyl pyruvic acid. The latter is reacted with thiobarbituric acid, and the red-coloured adduct formed is separated by reverse phase HPLC and quantified by measuring the absorbance at 549 nm. Some kraft pulps have been analysed to illustrate the contribution of hexeneuronic acid groups to the total amount of oxidizable structures present in such pulps.

  1. Physico-chemical characterization of protein associated polysaccharides extracted from sugar beet pulp

    USDA-ARS?s Scientific Manuscript database

    Sugar Beet Pulp (SBP), contains 67 to 80% (dry weight) of potentially valuable polysaccharides. We have solubilized and separated polysaccharides from SBP into three fractions with steam assisted flash extraction (SAFE) employed to solubilize the first and second fractions. Pectin, the first fract...

  2. Converting waste gases from pulp mills into value-added chemicals

    EPA Science Inventory

    Engineering, Miami University, 64 J Engineering Building, Oxford, OH, 45056 The pulp and paper industry generates large amounts of HAPs, VOCs and total reduced sulfur compounds (TRSs) of the various sources. As the industry is moving to a sustainable future, the U.S. EPA and Mia...

  3. A comparative evaluation of explosion hazards in chemical and mechanical pulp bleaching systems

    Treesearch

    Peter W. Hart; Alan W. Rudie

    2010-01-01

    Over the past several years, at least three pulp mills in North America have experienced catastrophic events that resulted in the explosion of pumps, mixers, and tanks. All these mills were using 50% concentration hydrogen peroxide at the site of the explosions. In at least two instances, alkali catalyzed decomposition of peroxide is implicated in the explosion....

  4. Converting waste gases from pulp mills into value-added chemicals

    EPA Science Inventory

    Engineering, Miami University, 64 J Engineering Building, Oxford, OH, 45056 The pulp and paper industry generates large amounts of HAPs, VOCs and total reduced sulfur compounds (TRSs) of the various sources. As the industry is moving to a sustainable future, the U.S. EPA and Mia...

  5. Physico-chemical characterization of alkaline soluble polysaccharides from sugar beet pulp

    USDA-ARS?s Scientific Manuscript database

    We have studied the global structure of microwave-assisted alkaline soluble polysaccharides (ASP) isolated from fresh sugar beet pulp. The objective was to minimize the disassembly and possibly the degradation of these polysaccharides during extraction. Prior to ASP microwave assisted-extraction (...

  6. Physico-chemical characterization of a cellulosic fraction from sugar beet pulp

    USDA-ARS?s Scientific Manuscript database

    The residue of sugar beet pulp from which pectin and alkaline soluble polysaccharides have been removed by microwave assisted extraction (MAE) or conventional heat was treated with sodium monochloroacetate under alkaline pH to convert the residual cellulose present to carboxy methyl cellulose (CMC)....

  7. Effects of thermal processing and pulp filtration on physical, chemical and sensory properties of winter melon juice.

    PubMed

    Sun, Xiuxiu; Baldwin, Elizabeth A; Plotto, Anne; Manthey, John A; Duan, Yongping; Bai, Jinhe

    2017-01-01

    Winter melon (Benincasa hispida) is a widely consumed crop in Asia, and believed to impart special benefits to human health. The nutritional composition and sensory properties of four juice types, resulting from a combination of pulp levels (low/high pulp, LP/HP) and thermal processing (with/without boiling, B/NB), LPNB, HPNB, LPB and HPB, were compared. The juices had low sugars (< 20 g kg(-1) ) and low titratable acidity (about 2 g kg(-1) ). The insoluble solids, glucose, fructose and citric acid content in LP juice were significantly lower than in HP juice. The phenolic amino acids phenylalanine, tyrosine, and tryptophan were detected at 10-45 mg L(-1) levels, and the antioxidant activity ranged from 36 to 49 mg gallic acid L(-1) . C6 and C9 aldehydes were mainly found in HP juice, and boiling induced the accumulation of sulfur compounds and C5 aldehydes. The LPNB juice showed the highest acceptability in the sensory panel. The frozen concentrated orange juice (FCOJ) reconstituted with LPNB was preferable to regular FCOJ for 31% of panelists and not different for 20% of panelists. The low sugar/low acid LPNB juice with 'fresh' flavor could be developed to replace water for reconstituting FCOJ with enhanced nutritional value. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Adsorption of cationized eucalyptus heteropolysaccharides onto chemical and mechanical pulp fibers.

    PubMed

    Hu, Guichun; Fu, Shiyu; Liu, Hao; Lucia, Lucian A

    2015-06-05

    Adsorption of native eucalyptus heteropolysaccharides onto bleached softwood and hardwood kraft pulps and bleached CTMP was explored in this work to potentially improve the mechanical properties of the final furnish. It was found that adsorption of native heteropolysaccharides onto softwood kraft pulp was slightly higher than hardwood; however, heteropolysaccharides with low arabinose content were preferentially adsorbed onto the hardwood fibers. Adsorption onto CTMP was the lowest, although the general phenomenon of native absorption was rather low under the applied conditions. A strategy to increase the absorption required cationizing the heteropolysaccharides with 2,3-epoxy propyltrimethylamonium chloride that in general significantly increased the overall phenomenon, again with the same general tendencies as observed for the native adsorption.

  9. Evaluating chemical-, mechanical-, and bio-pulping processes and their sustainability characterization using life cycle assessment

    Treesearch

    Tapas K. Das; Carl Houtman

    2004-01-01

    Pulp and paper manufacturing constitutes one of the largest industry segments in the United States in term of water and energy usage and total discharges to the environment. More than many other industries, however, this industry plays an important role in sustainable development because its chief raw material— wood fiber—is renewable. This industry provides an example...

  10. Chapter 6: Prehydrolysis Pulping with Fermentation Coproducts

    Treesearch

    T.H. Wegner; C.J. Houtman; A.W. Rudie; B.L. Illman; P.J. Ince; E.M. Bilek; T.W. Jeffries

    2013-01-01

    Although the term “integrateed biorefinery” is new, the concept has long been familiar to the pulp and paper industry, where processes include biomass boilers providing combined heat and power, and byproducts of pulping include turpentine, fatty acids and resin acids. In the dominant kraft (or sulfate) pulping process, dissolved lignin and chemicals from the pulp...

  11. Chemical-physical properties of TheraCal, a novel light-curable MTA-like material for pulp capping.

    PubMed

    Gandolfi, M G; Siboni, F; Prati, C

    2012-06-01

    To evaluate the chemical-physical properties of TheraCal, a new light-curable pulp-capping material composed of resin and calcium silicate (Portland cement), compared with reference pulp-capping materials (ProRoot MTA and Dycal). Calcium (Ca) and hydroxyl (OH) ion release over 28 days, solubility and water uptake (weight percentage variation, Δ%) at 24 h, cure depth and radiopacity of TheraCal, ProRoot MTA and Dycal were evaluated. Statistical analysis (P < 0.05) of release of ion was carried out by two-way repeated measures anova with Tukey, whilst one-way anova with Tukey test was used for the other tests. TheraCal released significantly more calcium than ProRoot MTA and Dycal throughout the test period. TheraCal was able to alkalinize the surrounding fluid initially to pH 10-11 (3 h-3 days) and subsequently to pH 8-8.5 (7-14 days). TheraCal had a cure depth of 1.7 mm. The solubility of TheraCal (Δ-1.58%) was low and significantly less than that of Dycal (Δ-4.58%) and ProRoot MTA (Δ-18.34%). The amount of water absorbed by TheraCal (Δ +10.42%) was significantly higher than Dycal (Δ +4.87%) and significantly lower than ProRoot MTA (Δ +13.96%). TheraCal displayed higher calcium-releasing ability and lower solubility than either ProRoot MTA or Dycal. The capability of TheraCal to be cured to a depth of 1.7 mm may avoid the risk of untimely dissolution. These properties offer major advantages in direct pulp-capping treatments. © 2012 International Endodontic Journal.

  12. Isolation and chemical identification of lipid derivatives from avocado (Persea americana) pulp with antiplatelet and antithrombotic activities.

    PubMed

    Rodriguez-Sanchez, Dariana Graciela; Flores-García, Mirthala; Silva-Platas, Christian; Rizzo, Sheryl; Torre-Amione, Guillermo; De la Peña-Diaz, Aurora; Hernández-Brenes, Carmen; García-Rivas, Gerardo

    2015-01-01

    Platelets play a pivotal role in physiological hemostasis. However, in coronary arteries damaged by atherosclerosis, enhanced platelet aggregation, with subsequent thrombus formation, is a precipitating factor in acute ischemic events. Avocado pulp (Persea americana) is a good source of bioactive compounds, and its inclusion in the diet as a source of fatty acid has been related to reduced platelet aggregability. Nevertheless, constituents of avocado pulp with antiplatelet activity remain unknown. The present study aims to characterize the chemical nature of avocado constituents with inhibitory effects on platelet aggregation. Centrifugal partition chromatography (CPC) was used as a fractionation and purification tool, guided by an in vitro adenosine diphosphate (ADP), arachidonic acid or collagen-platelet aggregation assay. Antiplatelet activity was initially linked to seven acetogenins that were further purified, and their dose-dependent effects in the presence of various agonists were contrasted. This process led to the identification of Persenone-C (3) as the most potent antiplatelet acetogenin (IC₅₀=3.4 mM) among the evaluated compounds. In vivo evaluations with Persenone A (4) demonstrated potential protective effects against arterial thrombosis (25 mg kg⁻¹ of body weight), as coagulation times increased (2-fold with respect to the vehicle) and thrombus formation was attenuated (71% versus vehicle). From these results, avocado may be referred to as a functional food containing acetogenin compounds that inhibit platelet aggregation with a potential preventive effect on thrombus formation, such as those that occur in ischaemic diseases.

  13. Enhanced chemical oxygen demand removal and flux reduction in pulp and paper wastewater treatment using laccase-polymerized membrane filtration.

    PubMed

    Ko, Chun-Han; Fan, Chihhao

    2010-09-15

    The purpose of this present study is to investigate the removal efficiency of chemical oxygen demand (COD) from pulp and paper wastewater using laccase-polymerized membrane filtration process. The membranes with molecular weight cut-off (MWCO) of 5000 and 10,000, 30,000 and 54,000 were used in a cross-flow module to treat the pulp and paper wastewater containing high phenolic constituents and COD. With 2.98 IU/L of activated laccase applied at room temperature for 180 min, the contaminants in raw wastewater and second effluent were polymerized to form larger molecules with average molecular weight of 1300 and 900 Da (Dalton), respectively. With laccase polymerization prior to filtration, over 60% removals of COD by the four investigated membranes were observed, compared with low COD removal without laccase polymerization. Moreover, the addition of laccase resulted in 4-14% reduction of membrane permeability during the first 180 min filtration operation due to gel layer formation by the polymerization. No further flux decline was observed afterwards indicating the steady state was reached and the membranes could be used to remove the polymerized pollutants without significant fouling. The maximum apparent resistance occurrence for raw wastewater treated with laccase also supported the effectiveness for COD removal with laccase polymerization before membrane filtration. Additionally, pretreatment by inactivated laccase only caused further flux reduction without additional removal of COD.

  14. Structural differences between the lignin-carbohydrate complexes present in wood and in chemical pulps.

    PubMed

    Lawoko, Martin; Henriksson, Gunnar; Gellerstedt, Göran

    2005-01-01

    Lignin-carbohydrate complexes (LCCs) were prepared in quantitative yield from spruce wood and from the corresponding kraft and oxygen-delignified pulps and were separated into different fractions on the basis of their carbohydrate composition. To obtain an understanding of the differences in lignin structure and reactivity within the various LCC fractions, thioacidolysis in combination with gas chromatography was used to quantify the content of beta-O-4 structures in the lignin. Periodate oxidation followed by determination of methanol was used to quantify the phenolic hydroxyl groups. Furthermore, size exclusion chromatography (SEC) of the thioacidolysis fractions was used to monitor any differences between the original molecular size distribution and that after the delignification processes. Characteristic differences between the various LCC fractions were observed, clearly indicating that two different forms of lignin are present in the wood fiber wall. These forms are linked to glucomannan and xylan, respectively. On pulping, the different LCCs have different reactivities. The xylan-linked lignin is to a large extent degraded, whereas the glucomannan-linked lignin undergoes a partial condensation to form more high molecular mass material. The latter seems to be rather unchanged during a subsequent oxygen-delignification stage. On the basis of these findings, a modified arrangement of the fiber wall polymers is suggested.

  15. Agricultural land application of pulp and paper mill sludges in the Donnacona area, Quebec: Chemical evaluation and crop response

    SciTech Connect

    Veillette, A.X.; Tanguay, M.G.

    1997-12-31

    Primary paper mill sludges from a thermomechanical pulp (TMP) mill were land applied at the rate of 20 metric ton per hectare (t/ha) for agricultural purposes in the Donnacona area, Quebec, in May 1994 and May 1995. Eleven agricultural sites featuring various crops were tested over two seasons to measure the impact of TMP primary paper mill sludges on soil, plant tissue and crop yield. Cereal and potato crops showed a significant increase in yield. TMP Primary sludges were also applied at the rate of 225 t/ha for land reclamation purposes of one site at the end of 1994. Soils were tested every second month. Chemical crop analyses were also performed. The first year crop response was satisfactory. Combined (primary and secondary) TMP sludges were added at the rate of 200 t/ha in the beginning of 1996. Soil, vadose zone water and crop analysis are being investigated. Impressive crop responses were obtained in the 1996 season.

  16. Chemical characterization of lignin and lipid fractions in industrial hemp bast fibers used for manufacturing high-quality paper pulps.

    PubMed

    Gutiérrez, Ana; Rodríguez, Isabel M; del Río, José C

    2006-03-22

    The chemical composition of lignin and lipids of bast fibers from industrial hemp (Cannabis sativa) used for high-quality paper pulp production was studied. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of fibers showed a lignin with a p-hydroxyphenyl:guaiacyl:syringyl unit (H:G:S) molar proportion of 13:53:34 (S/G ratio of 0.64). p-Hydroxycinnamic acids, namely, p-coumaric and ferulic acids, were found in only trace amounts. Among the lipids, the main compounds identified by GC/MS of the hemp fibers extracts were series of n-alkanes, free and esterified sterols and triterpenols, waxes, and long-chain n-fatty acids. Other compounds such as n-aldehydes, n-fatty alcohols, steroid hydrocarbons, and steroid and triterpenoid ketones as well as steryl glycosides were also found.

  17. Infrared spectroscopy as alternative to wet chemical analysis to characterize Eucalyptus globulus pulps and predict their ethanol yield for a simultaneous saccharification and fermentation process.

    PubMed

    Castillo, Rosario Del P; Baeza, Jaime; Rubilar, Joselyn; Rivera, Alvaro; Freer, Juanita

    2012-12-01

    Bioethanol can be obtained from wood by simultaneous enzymatic saccharification and fermentation step (SSF). However, for enzymatic process to be effective, a pretreatment is needed to break the wood structure and to remove lignin to expose the carbohydrates components. Evaluation of these processes requires characterization of the materials generated in the different stages. The traditional analytical methods of wood, pretreated materials (pulps), monosaccharides in the hydrolyzated pulps, and ethanol involve laborious and destructive methodologies. This, together with the high cost of enzymes and the possibility to obtain low ethanol yields from some pulps, makes it suitable to have rapid, nondestructive, less expensive, and quantitative methods to monitoring the processes to obtain ethanol from wood. In this work, infrared spectroscopy (IR) accompanied with multivariate analysis is used to characterize chemically organosolv pretreated Eucalyptus globulus pulps (glucans, lignin, and hemicellulosic sugars), as well as to predict the ethanol yield after a SSF process. Mid (4,000-400 cm(-1)) and near-infrared (12,500-4,000 cm(-1)) spectra of pulps were used in order to obtain calibration models through of partial least squares regression (PLS). The obtained multivariate models were validated by cross validation and by external validation. Mid-infrared (mid-IR)/NIR PLS models to quantify ethanol concentration were also compared with a mathematical approach to predict ethanol yield estimated from the chemical composition of the pulps determined by wet chemical methods (discrete chemical data). Results show the high ability of the infrared spectra in both regions, mid-IR and NIR, to calibrate and predict the ethanol yield and the chemical components of pulps, with low values of standard calibration and validation errors (root mean square error of calibration, root mean square error of validation (RMSEV), and root mean square error of prediction), high correlation

  18. Chemical composition and pulping of date palm rachis and Posidonia oceanica--a comparison with other wood and non-wood fibre sources.

    PubMed

    Khiari, R; Mhenni, M F; Belgacem, M N; Mauret, E

    2010-01-01

    In the present paper, the valorisation of two residues: Posidonia oceanica and date palm rachis was investigated. First, their chemical composition was studied and showed that they present amounts of holocellulose, lignin and cellulose similar to those encountered in softwood and hardwood. Extractives in different solvents and ash contents are relatively high. Moreover, ash composition assessment showed that silicon is the major component (17.7%) for P. oceanica. The high ash quantity and the low DP (about 370) may be considered as serious disadvantages of P. oceanica, in the pulping and papermaking context. Oppositely, the properties of rachis date palm and those of the ensuing pulp, obtained from a classical soda-anthraquinone cooking, demonstrated the suitability of this agricultural by-product for papermaking. Preliminary tests conducted on unrefined pulp suspensions and handsheets from date palm rachis in terms of freeness, Water Retention Value and mechanical properties allowed confirming the good quality of date palm rachis fibres.

  19. Chemical characterization of lignin from kraft pulping black liquor of Acacia mangium

    NASA Astrophysics Data System (ADS)

    Hermiati, Euis; Risanto, Lucky; Lubis, M. Adly Rahandi; Laksana, Raden Permana Budi; Dewi, Aniva Rizkia

    2017-01-01

    In order to know the proper use of lignin derived from pulping process of A. mangium, it is important to study the characteristics of lignin obtained from this species. The objective of this research was to study the characteristics of lignin isolated from kraft pulping black liquor of A. mangium. Lignin was isolated from the black liquor by single step and two step acid precipitation. The lignins were characterized for their moisture, ash, acid soluble lignin (ASL), and acid insoluble lignin (AIL) contents. Elemental composition, FTIR spectra, UV spectra, and microscopic structure using SEM were also analyzed. The yield of lignin obtained through one step precipitation of black liquor (45.76%) was much higher than that through two step precipitation (7.38%), while ash contents of lignin from one step and two step precipitations were almost the same. Ultimate analysis shows that carbon content in lignin from one step precipitation was lower than that from two step precipitation, while hydrogen, oxygen, nitrogen and sulfur content were relatively the same. Two step precipitation could increase the AIL and decrease the ASL content of the lignin isolate. Results of UV analysis show that in neutral medium (dioxane-water) the two lignin isolates had strong absorbance at 240 nm, while in alkaline medium (NaOH pH 12) there were strong absorption at 210 nm, and weak absorption at 280 nm. The FT-IR spectra reveal that the two lignin isolates had similar functional groups. This means that the removal of sugar from lignin did not change the lignin structure. The SEM analysis shows that both lignin isolates still contain some dirts.

  20. Evaluation of a value prior to pulping-thermomechanical pulp business concept. Part 2.

    Treesearch

    Ted Bilek; Carl Houtman; Peter Ince

    2011-01-01

    Value Prior to Pulping (VPP) is a novel biorefining concept for pulp mills that includes hydrolysis extraction of hemicellulose wood sugars and acetic acid from pulpwood prior to pulping. The concept involves conversion of wood sugars via fermentation to fuel ethanol or other chemicals and the use of remaining solid wood material in the pulping process. This paper...

  1. Identification of compounds associated with testosterone depressions in fish exposed to bleached kraft pulp and paper mill chemical recovery condensates.

    PubMed

    Belknap, Andrew M; Solomon, Keith R; MacLatchy, Deborah L; Dubé, Monique G; Hewitt, L Mark

    2006-09-01

    In previous experiments, bleached kraft chemical recovery condensates generated during softwood pulp production have been identified as a primary source of substances causing testosterone depressions in mummichog (Fundulus heteroclitus). Recent toxicity identification evaluations have encountered inconsistencies in the potential of condensates and fractions to reduce steroid concentrations between three repeated exposures. To assess the sources of these inconsistencies, temporal assessments of condensate extractives and analytical methodologies were evaluated. Condensates were collected during a six-month period, extracted by solid-phase extraction (SPE), and analyzed by gas chromatography-mass spectrometry and gas chromatography-flame photometric detection. All unique extractives were cataloged by mass spectra, peak area, and gas chromatographic retention time, and nine were confirmed and quantified against authentic standards. Confirmed components included phenolic guaiacyl-based lignin degradation products, sulfur (S9), three diterpenoids, and a dimethoxy stilbene. Concentrations of confirmed condensate extractives were consistent in all samples collected. Spiking experiments of confirmed extractives revealed substantial losses following high-pressure liquid chromatographic fractionation and three different methods of fraction preparation. In an effort to propose chemical classes associated with biological activity, all unique condensate extractives in previously established bioactive and inactive fractions were classified based on their potential to depress testosterone in mummichog. Of 39 unique components in bioactive SPE extracts of condensates, six were associated with hormonal activity. Mass spectral interpretation indicated hydroxylated diterpenoids, sesquiterpenoids, and a lignin-derived stilbene as classes of chemicals associated with steroid depressions.

  2. Interaction between chitosan-based clay nanocomposites and cellulose in a chemical pulp suspension.

    PubMed

    Lai, Minghua; Liu, Pai; Lin, Huanbin; Luo, Yuqiong; Li, Houbin; Wang, Xiaoying; Sun, Runcang

    2016-02-10

    Quaternized chitosan/organic montmorillonite (QCS/OMMT) nanocomposites were synthesized under microwave irradiation. XRD and TEM analyses confirmed that QCS intercalated into the interlayer of OMMT and clay layers distributed uniformly in QCS matrix. QCS/OMMT nanocomposites were used as retention and drainage-aid agents in pulp suspension, during which the interface behavior of positively charged QCS/OMMT nanocomposites on negatively charged cellulosic substrate and CaCO3 substrate was investigated. With the addition of QCS/OMMT nanocomposites, the particle size of cellulosic substrate increased, while the beating degree and the total residual carbohydrate concentration decreased. The results indicated that QCS/OMMT nanocomposite made a difference in paper making process through the charge patch interaction. Moreover, QCS/OMMT nanocomposites had a strong interaction with CaCO3, which was significant in fiber fines retention and paper production. When the mass ratio of QCS to OMMT was 8:1, the QCS/OMMT nanocomposite demonstrated the strongest retention and drainage-aid effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Chemical composition and physical quality characteristics of Ghanaian cocoa beans as affected by pulp pre-conditioning and fermentation.

    PubMed

    Afoakwa, Emmanuel Ohene; Quao, Jennifer; Takrama, Jemmy; Budu, Agnes Simpson; Saalia, Firibu Kwesi

    2013-12-01

    Investigations were conducted to evaluate the effects of pod storage (as a means of pulp preconditioning) and fermentation on the chemical composition and physical characteristics of Ghanaian cocoa beans. A 4 × 2 full factorial design with factors as pod storage (0, 7, 14, 21 days) and cocoa treatment (fermented and unfermented) were conducted. Samples were analyzed for their chemical composition (moisture, crude fat, crude protein, ash and carbohydrate content) and mineral content using standard analytical methods. The physical qualities of the beans were analyzed for their proportions of cocoa nibs, shells and germ. Fermentation and increasing pod storage resulted in significant (P < 0.05) decreases in ash (3.48-2.92%), protein (21.63-17.62%) and fat (55.21-50.40%) content of the beans while carbohydrate content increased from 15.47% to 24.93% with both treatments. As well, increasing pod storage and fermentation significantly (P < 0.05) increased the copper content of the beans from while reductions in Mg and K occurred. Amongst the minerals studied, potassium was the most abundant mineral followed by magnesium, phosphorus and calcium in the fermented cocoa beans. Proportion of cocoa nibs also increased from with increasing pod storage and fermentation whiles reductions in shell content and no appreciable changes in germ proportions were noted.

  4. EDTA soluble chemical components and the conditioned medium from mobilized dental pulp stem cells contain an inductive microenvironment, promoting cell proliferation, migration, and odontoblastic differentiation.

    PubMed

    Kawamura, Rei; Hayashi, Yuki; Murakami, Hiroshi; Nakashima, Misako

    2016-05-25

    The critical challenge in tissue engineering is to establish an optimal combination of stem cells, signaling morphogenetic molecules, and extracellular matrix scaffold/microenvironment. The extracellular matrix components of teeth may be reconstituted as an inductive microenvironment in an ectopic tooth transplantation bioassay. Thus, the isolation and identification of the chemical components of the inductive microenvironment in pulp/dentin regeneration will accelerate progress towards the goal of tissue engineering of the tooth. The teeth demineralized in 0.6 M hydrochloric acid were sequentially extracted by 4.0 M guanidine hydrochloride (GdnHCl), pH 7.4, and 0.5 M ethylenediaminetetraacetic acid (EDTA), pH 7.4. The extracted teeth were transplanted into an ectopic site in severe combined immunodeficiency (SCID) mice with mobilized dental pulp stem cells (MDPSCs). The unextracted tooth served as a positive control. Furthermore, the soluble components for the inductive microenvironment, the GdnHCl extracts, or the EDTA extracts together with or without MDPSC conditioned medium (CM) were reconstituted systematically with autoclaved teeth in which the chemical components were completely inactivated and only the physical microenvironment was preserved. Their pulp/dentin regenerative potential and angiogenic potential were compared 28 days after ectopic tooth transplantation by histomorphometry and real-time RT-PCR analysis. Expression of an odontoblastic marker, enamelysin, and a pulp marker, thyrotropin-releasing hormone degrading enzyme (TRH-DE), was lower, and expression of a periodontal cell marker, anti-asporin/periodontal ligament-associated protein 1 (PLAP-1), was higher in the transplant of the EDTA-extracted teeth compared with the GdnHCl-extracted teeth. The autoclaved teeth reconstituted with the GdnHCl extracts or the EDTA extracts have weak regenerative potential and minimal angiogenic potential, and the CM significantly increased this potential

  5. Physico-chemical characterization of protein-associated polysaccharides extracted from sugar beet pulp.

    PubMed

    Fishman, Marshall L; Chau, Hoa K; Qi, Phoebe X; Hotchkiss, Arland T; Yadav, Madhav P

    2013-02-15

    We have solubilized and separated polysaccharides from sugar beet pulp (SBP) into three fractions with steam assisted flash extraction (SAFE). For pectin, recovery ranged from 8 to 14%, degree of methy-esterification 66-73%, crude protein 1.3-1.7%, M(w) 262-318 kDa, η(w) 0.22-0.23 dL/g, Rg(z) 36-39 nm and Rh(z) 41-42 nm. For alkaline soluble polysaccharides, (ASP I) recovery ranged from 4.0 to 6.5%, crude protein 1.2-4.8%, weight average molar mass (M(w)) 66-68 kDa, weight average intrinsic viscosity (η(w)) 0.27-0.30 dL/g, z-average radius of gyration (Rg(z)) 25-29 nm and z-average hydrated radius (Rh(z)) 10-11 nm. ASP II recovery ranged from 2.0 to 8.6%, crude protein 1.2-4.8%, M(w) 299-339 kDa, η(w) 0.22-0.33 dL/g, Rg(z) 33-34 nm and Rh(z) 30-34 nm. Recovery of the residue mainly cellulose, ranged from 20.3 to 22.3%. The cellulose in this fraction was converted to carboxymethyl cellulose (CMC). The CMC fraction contained 0.33-0.43 crude protein and had an M(w) ranging from 127 to 263 kDa, η(w) 3.6-8.0 dL/g, Rg(z) 35-45 nm and Rh(z) 27-40 nm.

  6. Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries: Main Report and Appendices (CD-ROM)

    SciTech Connect

    Not Available

    2002-10-01

    The main report on this CD assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performace and efficiency improvements. The Appendices on this CD provide supporting information for the analyses and provides and recommendations for assessing the effectiveness of the U.S. Department of Energy BestPractices Steam Program.

  7. Significant increases in pulping efficiency in C4H-F5H-transformed poplars: improved chemical savings and reduced environmental toxins.

    PubMed

    Huntley, Shannon K; Ellis, Dave; Gilbert, Margarita; Chapple, Clint; Mansfield, Shawn D

    2003-10-08

    The gene encoding ferulate 5-hydroxylase (F5H) was overexpressed in poplar (Populus tremula x Populus alba) using the cinnamate-4-hydroxylase (C4H) promoter to drive expression specifically in cells involved in the lignin biosynthetic pathway and was shown to significantly alter the mole percentage of syringyl subunits in the lignin, as determined by thioacidolysis. Analysis of poplar transformed with a C4H-F5H construct demonstrated significant increases in chemical (kraft) pulping efficiency from greenhouse-grown trees. Compared to wild-type wood, decreases of 23 kappa units and increases of >20 ISO brightness units were observed in trees exhibiting high syringyl monomer concentrations. These changes were associated with no significant modification in total lignin content and no observed phenotypic differences. C4H-F5H-transformed trees could increase pulp throughputs at mills by >60% while concurrently decreasing chemicals employed during processing (chemical pulping and bleaching) and, consequently, the amount of deleterious byproducts released into the environment.

  8. New technology in pulping and bleaching

    Treesearch

    R. H. Atalla; R. S. Reiner; C. J. Houtman; E. L. Springer

    2004-01-01

    Innovation in advancing technoogies for production of pulp and paper has been driven, by and large, by the needs to reduce the environmental impact of pulp mills or to enhance the yield in processes of conversion of wood to fibers. "Fiberization" of wood chips is carred out in two categores of processes. One, chemical pulping relies on removing the lignin...

  9. An integrated biorefinery concept for conversion of sugar beet pulp into value-added chemicals and pharmaceutical intermediates.

    PubMed

    Cárdenas-Fernández, Max; Bawn, Maria; Hamley-Bennett, Charlotte; Bharat, Penumathsa K V; Subrizi, Fabiana; Suhaili, Nurashikin; Ward, David P; Bourdin, Sarah; Dalby, Paul A; Hailes, Helen C; Hewitson, Peter; Ignatova, Svetlana; Kontoravdi, Cleo; Leak, David J; Shah, Nilay; Sheppard, Tom D; Ward, John M; Lye, Gary J

    2017-09-21

    Over 8 million tonnes of sugar beet are grown annually in the UK. Sugar beet pulp (SBP) is the main by-product of sugar beet processing which is currently dried and sold as a low value animal feed. SBP is a rich source of carbohydrates, mainly in the form of cellulose and pectin, including d-glucose (Glu), l-arabinose (Ara) and d-galacturonic acid (GalAc). This work describes the technical feasibility of an integrated biorefinery concept for the fractionation of SBP and conversion of these monosaccharides into value-added products. SBP fractionation is initially carried out by steam explosion under mild conditions to yield soluble pectin and insoluble cellulose fractions. The cellulose is readily hydrolysed by cellulases to release Glu that can then be fermented by a commercial yeast strain to produce bioethanol at a high yield. The pectin fraction can be either fully hydrolysed, using physico-chemical methods, or selectively hydrolysed, using cloned arabinases and galacturonases, to yield Ara-rich and GalAc-rich streams. These monomers can be separated using either Centrifugal Partition Chromatography (CPC) or ultrafiltration into streams suitable for subsequent enzymatic upgrading. Building on our previous experience with transketolase (TK) and transaminase (TAm) enzymes, the conversion of Ara and GalAc into higher value products was explored. In particular the conversion of Ara into l-gluco-heptulose (GluHep), that has potential therapeutic applications in hypoglycaemia and cancer, using a mutant TK is described. Preliminary studies with TAm also suggest GluHep can be selectively aminated to the corresponding chiral aminopolyol. The current work is addressing the upgrading of the remaining SBP monomer, GalAc, and the modelling of the biorefinery concept to enable economic and Life Cycle Analysis (LCA).

  10. Novel bleaching of thermomechanical pulp for improved paper properties

    Treesearch

    Marguerite S. Sykes; John H. Klungness; Freya. Tan

    2002-01-01

    Production of mechanical pulp is expected to increase significantly to meet the growing global demand for paper. Mechanical pulping uses wood resources more efficiently with less negative impact on the environment than does chemical pulping. However, several problems related to mechanical pulping need to be resolved: high energy consumption, low paper strength...

  11. Effect of temperature-controlled fermentation on physico-chemical properties and lactic acid bacterial count of durian (Durio zibethinus Murr.) pulp.

    PubMed

    Wasnin, Ramdiah M; Karim, Muhammad Shahrim Abdul; Ghazali, Hasanah Mohd

    2014-11-01

    Effects of controlled-temperature fermentation on several physico-chemical properties, lactic acid bacteria (LAB) counts and aroma of durian pulp were examined by storing fresh durian pulp was mixed with 2 % (w/w) salt and stored at 15 °C, 27 °C and 40 °C for 10 days. Storage at 15 °C did not affect the properties of the pulp much. However, at 27 °C and 40 °C, pH and total soluble solids decreased up to 60 % and 52 %, respectively, with greater losses at 27 °C. Titratable acidity, which increased at 27 °C, was due to lactic and acetic acids formation. Loss of sucrose and increases in glucose were greater at 27 °C. LAB population increased up to Day 3 of storage, and then decreased slightly. Principal component analysis based on aroma examination using a zNose(TM) showed better retention of aroma profile at 27 °C. Overall, durian fermented at 27 °C was more acceptable than the one prepared at 40 °C, and it is ready to be consumed between Day 4 and 6.

  12. The effect of chemical composition on microfibrillar cellulose films from wood pulps: mechanical processing and physical properties.

    PubMed

    Spence, Kelley L; Venditti, Richard A; Habibi, Youssef; Rojas, Orlando J; Pawlak, Joel J

    2010-08-01

    Films of microfibrillated celluloses (MFCs) from pulps of different yields, containing varying amounts of extractives, lignin, and hemicelluloses, were produced by combining refining and high-pressure homogenization techniques. MFC films were produced using a casting-evaporation technique and the physical and mechanical properties (including density, roughness, fold endurance and tensile properties) were determined. Homogenization of bleached and unbleached Kraft pulps gave rise to highly individualized MFCs, but not for thermo-mechanical pulp (TMP). The resulting MFC films had a roughness equivalent to the surface upon which the films were cast. Interestingly, after homogenization, the presence of lignin significantly increased film toughness, tensile index, and elastic modulus. The hornification of fibers through a drying and rewetting cycle prior to refining and homogenization did not produce any significant effect compared to films from never-dried fibers, indicating that MFC films can potentially be made from low-cost recycled cellulosic materials.

  13. Chemical characterization of pitch deposits produced in the manufacturing of high-quality paper pulps from hemp fibers.

    PubMed

    Gutiérrez, Ana; del Río, José C

    2005-09-01

    The composition of pitch deposits occurring in pulp sheets and mill circuits during soda/anthraquinone pulping and elemental chlorine-free pulp bleaching of bast fibers of industrial hemp (Cannabis sativa) was studied. Pitch deposits were extracted with acetone, and the extracts analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Acetone extracts (15-25% of pitch deposits) were constituted by the defoamers used at the mill and by lipophilic extractives from hemp fibers. Acetone-insoluble residues (75-85% of pitch deposits) were analyzed by pyrolysis-GC/MS in the presence and absence of tetramethylammonium hydroxide. These residues were constituted by salts of fatty acids (arising from hemp fibers) with calcium, magnesium, aluminum and other cations that were identified in the deposits. It was concluded that inappropriate use of defoamer together with the presence of multivalent ions seemed to be among the causes of hemp extractives deposition in the pitch problems reported here.

  14. Chemical and microbiological changes during vermicomposting of coffee pulp using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis) species.

    PubMed

    Raphael, Kurian; Velmourougane, K

    2011-06-01

    Coffee pulp is the main solid residue from the wet processing of coffee berries. Due to presence of anti-physiological and anti-nutritional factors, coffee pulp is not considered as adequate substrate for bioconversion process by coffee farmers. Recent stringent measures by Pollution Control authorities, made it mandatory to treat all the solid and liquid waste emanating from the coffee farms. A study was conducted to evaluate the efficiency of an exotic (Eudrilus eugeniae) and a native earthworm (Perionyx ceylanesis) from coffee farm for decomposition of coffee pulp into valuable vermicompost. Exotic earthworms were found to degrade the coffee pulp faster (112 days) as compared to the native worms (165 days) and the vermicomposting efficiency (77.9%) and vermicompost yield (389 kg) were found to significantly higher with native worms. The multiplication rate of earthworms (280%) and worm yield (3.78 kg) recorded significantly higher with the exotic earthworms. The percentage of nitrogen, phosphorous, potassium, calcium and magnesium in vermicompost was found to increase while C:N ratio, pH and total organic carbon declined as a function of the vermicomposting. The plant nutrients, nitrogen (80.6%), phosphorus (292%) and potassium (550%) content found to increase significantly in the vermicompost produced using native earthworms as compared to the initial values, while the calcium (85.7%) and magnesium (210%) content found to increase significantly in compost produced utilizing exotic worms. Vermicompost and vermicasts from native earthworms recorded significantly higher functional microbial group's population as compared to the exotic worms. The study reveals that coffee pulp can be very well used as substrate for vermicomposting using exotic (Eudrilus eugeniae) and native earthworm (Perionyx ceylanesis).

  15. Control of the Accumulation of Non-Process Elements in Pulp Mills with Bleach Filtrate Reuse: A Chemical Equilibrium Approach to Predicting the Partitioning of Metals in Pulp Mill and Bleach Plant Streams

    SciTech Connect

    Frederick, W.J. Jr.; Rudie, A.W.; Schmidl, G.W.; Sinquefield, S.A.; Rorrer, G.L.; Laver, M.L.; Yantasee, W.; Ming, D.

    2000-08-01

    The overall goal of this project was to develop fundamental, experimentally based methods for predicting the solubility or organic and inorganic matter and their interactions in recycled effluent from kraft pulp mills and bleach plants. This included: characterizing the capacity of wood pulp and dissolved organic matter to bind metal ions, developing a thermodynamic database of properties needed to describe the solubility of inorganic matter in pulp mill streams, incorporation of the database into equilibrium calculation software for predicting the solubility of the metals of interest, and evaluating its capability to predict the distribution of the metals between pulp fibers, inorganic precipitates, and solution.

  16. POZONE technology to bleach pulp

    SciTech Connect

    Wang, H.; Shi, Y.; Le, L.; Wang, S.M.; Wei, J.; Chang, S.G.

    1997-09-01

    Currently, there has been a move in the pulp and paper industry to reduce or eliminate chlorine-based bleaching due to environmental concerns. The POZONE process, a chemical means of ozone production, has been used to bleach wood pulp. The brightness, Kappa number, and viscosity of wood pulp subjected to POZONE treatment have been determined. Brightness increases of up to 44 points and Kappa number decreases of as much as 22 points have been achieved. Promise for effective industrial application has been demonstrated.

  17. Alkaline pulping of some eucalypts from Sudan.

    PubMed

    Khristova, P; Kordsachia, O; Patt, R; Dafaalla, S

    2006-03-01

    Four eucalypts (Eucalyptus camaldulensis, Eucalyptus microtheca, Eucalyptus tereticornis and Eucalyptus citriodora) grown in Sudan were examined for their suitability for pulping and papermaking with different alkaline methods. Their physical, morphological and chemical characteristics are reported. The pulping trials with E. citriodora and E. tereticornis were carried out using the kraft-AQ, soda-AQ, modified AS/AQ (ASA), ASAM and kraft methods. For the other two species, only the ASAM and the kraft process were applied. ASAM pulping gave the best results in terms of yield, degree of delignification, mechanical and optical pulp properties. The best pulps, obtained in kraft and ASAM cooking of E. citriodora, were bleached to 88% ISO brightness in a totally chlorine free bleaching sequence (OQ1O/PQ2P). The bleached pulps, especially the ASAM pulp, showed good papermaking properties and would be suitable for manufacture of writing and printing grades of paper.

  18. Effect of sucrose and pectin addition on physical, chemical, thermal and rheological properties of frozen/thawed pineapple pulps

    NASA Astrophysics Data System (ADS)

    Conceição, Márcia Cavalcante; Fernandes, Tatiana Nunes; Prado, Mônica Elisabeth Torres; de Resende, Jaime Vilela

    2012-09-01

    Pectin (0-1.0 g/100 mL) and sucrose (0-20 g/100 mL) were added to pineapple pulp to improve their rheological properties, thermal properties and stability after freezing and thawing processes. The properties of the mixes were characterized before and after freezing and thawing. Samples were frozen at -20°C, and the freeze concentration was evaluated every 60 min. The thawing rate was evaluated at 19°C and quantified by photographic editing and image analysis software. The thawing rates and values for the freeze concentration were leveled out at pectin concentrations above 0.5 g/100 mL pectin, which indicated that pectin functions to maintain structural homogeneity during freezing. In the thawed samples, the plastic viscosity values were leveled out from pectin concentrations (0.25-0.75 g/100 mL) as the sucrose concentration increased when compared to unfrozen samples. The differences between the rheological parameters of the unfrozen and frozen/thawed pulps, the higher yield stress values after thawing were attributed to the size of suspended particles in the pulp. Applications can specify formulations of frozen products containing pectin, where these properties can be handled after thawing the product.

  19. Chemical characterization of organic microcontaminant sources and biological effects in riverine sediments impacted by urban sewage and pulp mill discharges.

    PubMed

    Chamorro, S; Hernández, V; Matamoros, V; Domínguez, C; Becerra, J; Vidal, G; Piña, B; Bayona, J M

    2013-01-01

    The Biobío River basin is highly impacted by a variety of anthropogenic activities such as pulp mills and urban wastewaters subjected to different treatment processes. This work assesses for the first time, the contamination source and biological effects (estrogenic and dioxin-like activities) in the river basin by the determination of 45 organic microcontaminants in seven sediment samples. Pressurized solvent extraction combined with two-dimensional comprehensive gas chromatography coupled to time of flight mass spectrometry was employed for this purpose. The organic microcontaminants identified comprise monoterpenes, sesquiterpenes, diterpenes, ionones, lineal alkyl benzenes, polycyclic aromatic hydrocarbons, musk fragrances, sterols and phathalate esters. The presence of pine and eucalyptus pulp mill effluents increased the abundance of resin-derived neutral compounds and monoterpenes respectively. A principal component analysis showed that the Biobío River basin was impacted by domestic wastewater treatment plants (WWTPs), pine or eucalyptus Kraft pulp mills and pyrolytic and pyrogenic processes. Finally, the recombinant yeast assays showed that the presence of estrogenic and dioxin-like activity was mostly located in sediments impacted by domestic WWTP effluents. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Recalcitrant organic compounds (chemical oxygen demand sources) in biologically treated pulp and paper mill effluents: Their fate and environmental impact in receiving waters

    SciTech Connect

    Archibald, F.; Roy-Arcand, L.; Methot, M.; Valeanu, L.

    1998-11-01

    Most North American pulp and paper mills now biologically treat (biotreat) their liquid effluent. However, treated water still contains effluent-derived recalcitrant organic material (EROM), measured as chemical oxygen demand (COD), for which emission limits exist in Europe and are being considered in the US. Production of microbially resistant, dissolved natural organic material (NOM) typically found in Canadian stream and lake waters occurs slowly under gentle conditions, while mill EROM is generated from lignocellulosics by faster and harsher processes. Similarity of the environmental effects of NOM and pulp and paper mill EROM are examined. Changes occurring over 4 months in biologically treated effluent from two modern Canadian mills and lake NOM when sealed in gas- and light-permeable bags and placed in a pristine Quebec lake are reported. Addition of microbial co-metabolites significantly improved the dark mineralization of organochlorines surviving mill biological treatment. Mill EROM was light sensitive, nonacutely toxic in the Microtox assay, and similar to NOM in the surrounding lake in most bulk properties. There was no evidence to suggest that placing specific limits on mill EROM (COD) emissions would be environmentally beneficial.

  1. Microbial reduction by two chemical-mechanical protocols in primary teeth with pulp necrosis and periradicular lesion - an in vivo study.

    PubMed

    Triches, Thaisa Cezária; de Figueiredo, Luciene Cristina; Feres, Magda; de Freitas, Sérgio Fernando Torres; Zimmermann, Gláucia Santos; Cordeiro, Mabel Mariela Rodríguez

    2014-01-01

    The objective of this study was to determine the efficacy of chemical-mechanical procedures of two endodontic protocols for septic content reduction of root canals from primary teeth with pulp necrosis and periradicular lesion. Twenty-four primary root canals with pulp necrosis and periradicular lesion were divided into two treatment groups (n=12): multiple-visit and single-visit protocols. Samples were collected using sterile paper points before and after endodontic cleaning followed by microbiological identification through checkerboard DNA-DNA hybridization. Statistical analysis was performed using Proportion Test for score=0 comparing the findings before and after treatment for each group (Wilcoxon's test) as well as the differences in scores between protocols (Mann-Whitney's test) (p<0.05). Data were expressed as prevalence (presence or absence) and estimate of the average count (x10(5) cells) of each species. Differences in proportions of score=0 prior to treatment were non-significant (p=0.415), demonstrating equivalence between groups. A significant increase in score=0 was detected after treatment for both groups (p<0.0001). Single-visit protocol achieved a significantly greater reduction in mean scoring following endodontic treatment (p=0.024). Both protocols were capable of significantly reducing septic content in root canals of primary teeth with periradicular lesion. Moreover, single-visit protocol showed greater efficacy in reducing endodontic infection.

  2. Effect of harvest time on physico-chemical properties and bioactive compounds of pulp and seeds of grape varieties.

    PubMed

    Özcan, Mehmet Musa; Juhaimi, Fahad Al; Gülcü, Mehmet; Uslu, Nurhan; Geçgel, Ümit; Ghafoor, Kashif; Dursun, Nesim

    2017-07-01

    In this study, physicochemical properties and bioactive compounds of three grape varieties (Cardinal, Müşküle and Razaki) harvested at the three different harvest times (on time, one and two weeks earlier) were investigated. The highest antioxidant activity, total phenolic and flavonoid contents were observed in Razaki pulp and these were 82.854%, 127.422 mg/100 g, 3.873 mg/g, respectively. The contents of bioactive compounds in grape seeds were found higher than those in pulps. Similarly, seed of Razaki had higher antioxidant activity (91.267%) and total phenolic content (477.500 mg/100 g) when compared to results of other varieties. The key phenolic compounds of all grape variety and seeds were gallic acid, 3,4-dihydroxybenzoic acid, (+)-catechin ve 1,2-dihydroxybenzene. The oil content of grape seeds ranged from 8.50% (Razaki harvested one week ago) to 19.024% (Müşküle harvested one week ago). The main fatty acids of grapeseed oils were linoleic, oleic and palmitic acids. In addition, the oil of Razaki seeds was rich in tocopherols when compared to the other varieties.

  3. Citrus pulp for cattle.

    PubMed

    Arthington, John D; Kunkle, William E; Martin, Amy M

    2002-07-01

    Citrus pulp is classified as an energy concentrate by-product feed. Citrus by-products fed to beef cattle include citrus molasses, citrus meal, wet citrus pulp, dried citrus pulp, and pelleted citrus pulp; however, in current production systems, pulp (wet, dry, and pelleted) is the only by-product commonly used. Citrus pulp production in the United States is limited to specific subtropical regions, of which south central Florida remains the largest with additional production in California and Texas.

  4. Raman spectroscopic characterization of wood and pulp fibers

    Treesearch

    Umesh Prasad Agarwal

    2008-01-01

    This chapter reviews applications of Raman spectroscopy in the field of wood and pulp fibers. Most of the literature examined was published between 1998 and 2006. In addition to introduction, this chapter contains sections on wood and components, mechanical pulp, chemical pulp, modified/treated wood, cellulose I crystallinity of wood fibers, and the self-absorption...

  5. Low Temperature Soda-Oxygen Pulping of Bagasse.

    PubMed

    Yue, Fengxia; Chen, Ke-Li; Lu, Fachuang

    2016-01-13

    Wood shortages, environmental pollution and high energy consumption remain major obstacles hindering the development of today's pulp and paper industry. Energy-saving and environmental friendly pulping processes are still needed, especially for non-woody materials. In this study, soda-oxygen pulping of bagasse was investigated and a successful soda-oxygen pulping process for bagasse at 100 °C was established. The pulping parameters of choice were under active alkali charge of 23%, maximum cooking temperature 100 °C, time hold at maximum temperature 180 min, initial pressure of oxygen 0.6 MPa, MgSO4 charge 0.5%, and de-pithed bagasse consistency 12%. Properties of the resultant pulp were screened yield 60.9%, Kappa number 14, viscosity 766 dm³/kg, and brightness 63.7% ISO. Similar pulps were also obtained at 110 °C or 105 °C with a cooking time of 90 min. Compared with pulps obtained at higher temperatures (115-125 °C), this pulp had higher screened yield, brightness, and acceptable viscosity, while the delignification degree was moderate. These results indicated that soda-oxygen pulping at 100 °C, the lowest cooking temperature reported so far for soda-oxygen pulping, is a suitable process for making chemical pulp from bagasse. Pulping at lower temperature and using oxygen make it an environmental friendly and energy-saving pulping process.

  6. [Vital pulp therapy of damaged dental pulp].

    PubMed

    Xuedong, Zhou; Dingming, Huang; Jianguo, Liu; Zhengwei, Huang; Xin, Wei; Deqin, Yang; Jin, Zhao; Liming, Chen; Lin, Zhu; Yanhong, Li; Jiyao, Li

    2017-08-01

    The development of an expert consensus on vital pulp therapy can provide practical guidance for the improvement of pulp damage care in China. Dental pulp disease is a major type of illness that adversely affects human oral health. Pulp capping and pulpotomy are currently the main methods for vital pulp therapy. Along with the development of minimal invasion cosmetic dentistry, using different treatment technologies and materials reasonably, preserving healthy tooth tissue, and extending tooth save time have become urgent problems that call for immediate solution in dental clinics. This paper summarizes the experiences and knowledge of endodontic experts. We develop a clinical path of vital pulp therapy for clinical work by utilizing the nature, approach, and degree of pulp damage as references, defense and self-repairing ability of pulp as guidance, and modern technologies of diagnosis and treatment as means.

  7. Bioelectrochemical treatment of paper and pulp wastewater in comparison with anaerobic process: integrating chemical coagulation with simultaneous power production.

    PubMed

    Krishna, K Vamshi; Sarkar, Omprakash; Venkata Mohan, S

    2014-12-01

    The efficiency of a bioelectrochemical treatment system (BET) to treat complex paper and pulp wastewater at two different pH conditions (6 and 7) in comparison with conventional anaerobic treatment process (AnT) was evaluated. Among the operating conditions, BET showed good treatment efficiency at pH 7 in terms of COD (BET/AnT: 55%/51%), nitrates (33.5%/19.1%), phosphates (33%/19%) and sulfates (58%/41%) in removal. The effluent obtained from BET system was subjected to coagulation for further treatment which showed good COD removal (BET/AnT, 95%/69%) and color (100%/68%). Bioelectrochemical analysis revealed higher catalytic currents in BET than AnT specific to oxidation and reduction. Besides, derivative of cyclic voltammetric scans (DCV) also supported the involvement of various membrane bound electron transferring complexes like FAD(H) bound enzymes, ubiquinone, NADH(+)/H(+) bound enzymes, etc. Experimental results demonstrated that BET system can be a viable platform to treat complex wastewaters with simultaneous energy recovery in integrated approach.

  8. Chemically coupled microwave and ultrasonic pre-hydrolysis of pulp and paper mill waste-activated sludge: effect on sludge solubilisation and anaerobic digestion.

    PubMed

    Tyagi, Vinay Kumar; Lo, Shang-Lien; Rajpal, Ankur

    2014-05-01

    The effects of alkali-enhanced microwave (MW; 50-175 °C) and ultrasonic (US) (0.75 W/mL, 15-60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limited to 33 and 39 % in MW pretreatment only (175 °C). It reached 78 and 66 % in combined MW-alkali pretreatment (pH 12 + 175 °C), respectively. Similarly, chemical oxygen demand and VSS solubilisation were 58 and 37 % in US pretreatment alone (60 min) and it improved by 66 and 49 % after US-alkali pretreatment (pH 12 + 60 min), respectively. The biogas yield for US 60 min-alkali (pH 12)-pretreated sludge was significantly improved by 47 and 20 % over the control and US 60 reactors, respectively. The biogas generation for MW (150 °C)-alkali (pH 12)-pretreated sludge was only 6.3 % higher than control; however, it was 8.3 % lower than the MW (150 °C) reactor, which was due to the inhibition of anaerobic activity under harsh thermal-alkali treatment condition.

  9. Evaluation of processed green and ripe mango peel and pulp flours (Mangifera indica var. Chokanan) in terms of chemical composition, antioxidant compounds and functional properties.

    PubMed

    Abdul Aziz, Noor Aziah; Wong, Lee Min; Bhat, Rajeev; Cheng, Lai Hoong

    2012-02-01

    Mango is a highly perishable seasonal fruit and large quantities are wasted during the peak season as a result of poor postharvest handling procedures. Processing surplus mango fruits into flour to be used as a functional ingredient appears to be a good preservation method to ensure its extended consumption. In the present study, the chemical composition, bioactive/antioxidant compounds and functional properties of green and ripe mango (Mangifera indica var. Chokanan) peel and pulp flours were evaluated. Compared to commercial wheat flour, mango flours were significantly low in moisture and protein, but were high in crude fiber, fat and ash content. Mango flour showed a balance between soluble and insoluble dietary fiber proportions, with total dietary fiber content ranging from 3.2 to 5.94 g kg⁻¹. Mango flours exhibited high values for bioactive/antioxidant compounds compared to wheat flour. The water absorption capacity and oil absorption capacity of mango flours ranged from 0.36 to 0.87 g kg⁻¹ and from 0.18 to 0.22 g kg⁻¹, respectively. Results of this study showed mango peel flour to be a rich source of dietary fiber with good antioxidant and functional properties, which could be a useful ingredient for new functional food formulations. Copyright © 2011 Society of Chemical Industry.

  10. Selective fractionation of Sugar Beet Pulp for release of fermentation and chemical feedstocks; optimisation of thermo-chemical pre-treatment.

    PubMed

    Hamley-Bennett, C; Lye, G J; Leak, D J

    2016-06-01

    The effect of time and pressure on the selective extraction of sugar beet pectin using steam pre-treatment on unprocessed Sugar Beet Pulp was evaluated using a design of experiments approach. This process gave the highest solubilisation of pectin oligomers at a relatively low pressure and longer time (5Bar, 24min), whilst leaving the majority of the cellulose fraction intact. This method of steam pre-treatment fits into the concept of a sugar beet biorefinery as it valorises an existing waste stream without requiring any further physical processing such as milling or dilution with water. The residual cellulose fraction was enriched in cellulose and could be effectively fermented into ethanol by yeast after enzymatic digestion, producing 0.48g ethanol per gram of glucose.

  11. Effects of different ratios and storage periods of liquid brewer's yeast mixed with cassava pulp on chemical composition, fermentation quality and in vitro ruminal fermentation.

    PubMed

    Kamphayae, Sukanya; Kumagai, Hajime; Angthong, Wanna; Narmseelee, Ramphrai; Bureenok, Smerjai

    2016-06-11

    This study aims to evaluate the chemical composition, fermentation quality and in vitro ruminal fermentation of various ratios and storage periods of liquid brewer's yeast (LBY) mixed with cassava pulp (CVP). Four mixtures of fresh LBY and CVP were made (LBY0, LBY10, LBY20 and LBY30 for LBY:CVP at 0:100, 10:90, 20:80 and 30:70, respectively) on a fresh matter basis, in 500 g in plastic bags and stored at 30 to 32 °C. After storage, the bags were opened weekly from weeks 0 to 4. Fermentation quality and in vitro gas production (IVGP) were determined, as well as the dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber, acid detergent fiber and acid detergent lignin contents. The contents of CP and EE increased, whereas all other components decreased, in proportion to LBY inclusion (p<0.01). The DM and OM contents gradually decreased in weeks 3 and 4 (p<0.05), while EE contents were lowest in week 0. The pH, ammonia nitrogen per total nitrogen (NH3-N/TN) and V-score in each mixture and storage period demonstrated superior fermentation quality (pH≤4.2, NH3-N/TN ≤12.5% and V-score >90%). The pH increased and NH3-N/TN decreased, with proportionate increases of LBY, whereas the pH decreased and NH3-N/TN increased, as the storage periods were extended (p<0.01). Although IVGP decreased in proportion to the amount of LBY inclusion (p<0.01), in vitro organic matter digestibility (IVOMD) was unaffected by the mixture ratios. The highest IVGP and IVOMD were observed in week 0 (p<0.01). We have found that the inclusion of LBY (as high as 30%) into CVP improves the chemical composition of the mixture, thereby increasing the CP content, while decreasing IVGP, without decreasing fermentation quality and IVOMD. In addition, a preservation period of up to four weeks can guarantee superior fermentation quality in all types of mixtures. Therefore, we recommend limiting the use of cassava pulp as a feed ingredient, given its low

  12. Comparison Study of Manometric Respirometric Test and Common Chemical Methods in the Determination of BOD bold7 in a Pulp and Paper Mill's Wastewaters

    PubMed Central

    Roppola, Katri; Kuokkanen, Toivo; Nurmesniemi, Hannu; Rämö, Jaakko; Pöykiö, Risto; Prokkola, Hanna

    2006-01-01

    The biological oxygen demand (BOD) test is widely used in many wastewater treatment plants. The conventional BOD tests are usually time-consuming and the results are often out of date for process control purposes. The aim of this research was to compare the manometric respirometric test with common chemical methods in the determination of BOD of wastewater from a pulp and paper mills as well as to evaluate the BOD 7 values of both wastewaters from the short-term respirometric measurements. The results showed that there were differences in the BOD7 values of paper mill samples measured by conventional and respirometric methods. The main cause was found to be the dilution solution used in the conventional BOD tests. Using the same mineral solution in the respirometric measurements diminished the difference remarkably. Evaluation of the BOD7 value after two or three days incubation was proved to work very well and the estimated results were close to measured values (deviations 1%–12%). PMID:17671628

  13. Advanced treatment by chemical oxidation of pulp and paper effluent from a plant manufacturing hardboard from waste paper.

    PubMed

    Tünay, O; Erdeml, E; Kabdaşli, I; Olmez, T

    2008-10-01

    This study attempts to evaluate the applicability of chemical oxidation processes to polish biologically treated effluent of a plant manufacturing hardboard from waste paper to comply with the discharge limit of 120 mg l(-1) chemical oxygen demand (COD). In the first step, a chemically assisted settling was applied. The optimum results were obtained with alum plus lime with the alum dose of 200 mg l(-1). In the second step, chemically assisted settling effluent was fed into an activated sludge system and over 80% COD removal was achieved. In the last step of the experimental study, a series of ozone oxidation and Fenton oxidation methods were tested to remove residual COD. Ozone oxidation provided 80% COD removal. An ozone dose of 40 mg min(-1) with a reaction time of two hours was found to be optimum. Catalytic ozonation by using ferric iron, as well as high pH ozonation, Fenton process and H2O2/O3 oxidation did not prove to be more efficient than plain ozonation under these study conditions.

  14. Remediation of lignin and its derivatives from pulp and paper industry wastewater by the combination of chemical precipitation and ozonation.

    PubMed

    De los Santos Ramos, W; Poznyak, T; Chairez, I; Córdova R, I

    2009-09-30

    In the present work the degradation of the lignin and its derivatives in the residual water of a paper industry by simple ozonation was investigated. The remediation of lignin was realized using the combination of the pre-treatment with chemical precipitation, using concentrated sulfuric acid (97.1%) at the pH 1 and 3, and of the simple ozonation of the filtered residual water at the pH 1, 3, 8 and 12. Since the high residues content (the initial chemical oxygen demand (COD) is 70,000 mg/L) in the experiments the diluted samples (1:10) were used. The previous precipitation has showed a significant effect on the reduction of the COD (77%) and color (96.1%). The sludge precipitated contents sulfolignin, which in the reaction with sulfuric acid was formed. In ozonation of the filtered residual water during 25 min at the pH 1, 3, 8 and 12 the follows by-products were formed: fumaric, maleic, malonic and formic acids. The biodegradability of the treated water in ozonation increases up 0.067-0.29. The effect of the precipitation and the ozonation conditions on the decolorization kinetics was evaluated.

  15. Basic effects of pulp refining on fiber properties--a review.

    PubMed

    Gharehkhani, Samira; Sadeghinezhad, Emad; Kazi, Salim Newaz; Yarmand, Hooman; Badarudin, Ahmad; Safaei, Mohammad Reza; Zubir, Mohd Nashrul Mohd

    2015-01-22

    The requirement for high quality pulps which are widely used in paper industries has increased the demand for pulp refining (beating) process. Pulp refining is a promising approach to improve the pulp quality by changing the fiber characteristics. The diversity of research on the effect of refining on fiber properties which is due to the different pulp sources, pulp consistency and refining equipment has interested us to provide a review on the studies over the last decade. In this article, the influence of pulp refining on structural properties i.e., fibrillations, fine formation, fiber length, fiber curl, crystallinity and distribution of surface chemical compositions is reviewed. The effect of pulp refining on electrokinetic properties of fiber e.g., surface and total charges of pulps is discussed. In addition, an overview of different refining theories, refiners as well as some tests for assessing the pulp refining is presented.

  16. Trace elements in bivalves from the Rio Cruces, Chile, trace watershed evolution after a major earthquake and challenge a postulated chemical spill from a pulp plant

    NASA Astrophysics Data System (ADS)

    Risk, M.; Burchell, M.; Nairn, R.; Tubrett, M.; Forsterra, G.

    2009-05-01

    In May, 1960, the largest recorded earthquake in the history of the planet hit southern Chile, dropping part of the course of the Rio Cruces by 2m and creating an extensive wetland. The Brazilian Waterweed Egeria densa colonised the area, and became a primary food source for large populations of the Black-necked Swan, Cygnus melancoryphus. In 2004, a large pulp mill commenced operations upstream on the river. According to local reports, immediately after the opening of the plant, the weed died and the swans left. There was public outcry, and a search for a cause or a culprit. It was postulated that some sort of chemical spill from the plant caused the weed to die, resulting in departure of the swans. In 2008, we collected specimens of the bivalve Diplodon chilensis from several locations downstream from the Plant and towards the wetland to see if there was evidence of a chemical spill recorded in the shells. We prepared thin-sections of the shells to observe growth line development and patterns. Additionally, shell samples were analysed for stable oxygen isotopes and trace elements, using LA-ICP/MS. Based on annual growth lines, some of the bivalves were long-lived, with an age of more than 50 years. These individuals settled in the river shortly after the earthquake, and have lived there continuously ever since. Annual and sub-annual banding was clear, and the annual cyclicity of the major bands was verified with oxygen isotope analysis. There are no changes in growth corresponding to 2004. Trace element scans provided a wealth of information on the evolution of this earthquake-impacted wetland. Barium, Strontium and Manganese all showed strong annual cyclicity. From the analysis of older specimens, we interpret the high peaks of the Ba signal as reflecting soil erosion-Ba peaks are large immediately after the earthquake, then they diminish through time. Sr is likely a temperature signal, and Mn reflects runoff. Minor peaks in Cu, As and Pb probably reflect

  17. Highly Energy Efficient Directed Green Liquor Utilization (D-GLU) Pulping

    SciTech Connect

    2007-07-01

    This factsheet describes a project that seeks to develop feasible chemical modifications during kraft pulping operations to obtain significant energy and product benefits for U.S. kraft pulp and paper mills.

  18. Determining the minimum conditions for soda-anthraquinone pulping of kenaf bast, core, and whole stalk fibers

    Treesearch

    James S. Han; Thomas A. Rymsza

    1999-01-01

    Chemical pulping of kenaf fiber is comparatively new. In this study, bast, core, and whole stalk kenaf fibers were pulped using a soda-AQ pulping process and various pulping conditions. Handsheets were evaluated for density, Canadian standard freeness, brightness, opacity, smoothness, and tensile, burst, and tear indexes and strength. The results indicate that...

  19. Impact of ultrasounds and high voltage electrical discharges on physico-chemical properties of rapeseed straw's lignin and pulps.

    PubMed

    Brahim, M; Checa Fernandez, B L; Regnier, O; Boussetta, N; Grimi, N; Sarazin, C; Husson, E; Vorobiev, E; Brosse, N

    2017-08-01

    In this study, ultrasound (US) and high voltage electrical discharges (HVED) were combined with chemical treatments (soda or organosolv) for rapeseed straw delignification. Delignification was improved by both physical pretreatments. US increased the extractability of hemicelluloses and HVED induced a partial degradation of cellulose. Best synergies were observed for HVED-soda and US-organosolv treatments. The obtained lignin fractions were characterized with (13)C NMR and 2D (1)H-(13)C HSQC. It was observed that the physical treatments affected the syringyl/guaiacyl (S/G) ratios. The values of S/G were ≈1.19, 1.31 and 1.75 for organosolv, HVED-organosolv and US-organosolv processes, suggesting recondensation reactions. The lignin fractions obtained from HVED-organosolv treatment contained less quantity of p-coumaric acid and ferulic acid as compared to those extracted by US-organosolv. Thermogravimetric analysis (TGA) revealed a better heat resistance of physically extracted lignins as compared to the control. The enzymatic digestibility increased by 24.92% when applying HVED to mild organosolv treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. High-yield pulping effluent treatment technologies

    SciTech Connect

    Su, W.X.; Hsieh, J.S. . School of Chemical Engineering)

    1993-03-01

    The objective of this report is to examine the high-yield (mechanical) pulp processes with respect to environmental issues affected by the discharge of their waste streams. Various statistics are given that support the view that high-yield pulping processes will have major growth in the US regions where pulp mills are located, and sites for projects in the development phase are indicated. Conventional and innovative effluent-treatment technologies applicable to these processes are reviewed. The different types of mechanical pulping or high-yield processes are explained, and the chemical additives are discussed. The important relationship between pulp yield and measure of BOD in the effluent is graphically presented. Effluent contaminants are identified, along with other important characteristics of the streams. Current and proposed environmental limitations specifically related to mechanical pulp production are reviewed. Conventional and innovative effluent-treatment technologies are discussed, along with their principle applications, uses, advantages, and disadvantages. Sludge management and disposal techniques become an intimate part of the treatment of waste streams. The conclusion is made that conventional technologies can successfully treat effluent streams under current waste-water discharge limitations, but these systems may not be adequate when stricter standards are imposed. At present, the most important issue in the treatment of pulp-mill waste is the management and disposal of the resultant sludge.

  1. Pulp and paper from blue agave waste from tequila production.

    PubMed

    Idarraga, G; Ramos, J; Zuñiga, V; Sahin, T; Young, R A

    1999-10-01

    Pulping of blue agave waste, from the production of tequila, was evaluated by both chemical and biomechanical pulping processes. Two conventional and two organosolv systems were used to pulp the agave waste under a standard set of conditions. The soda-ethanol process was superior in terms of delignification and pulp properties in comparison to the soda and ethanol organosolv processes for pulping of agave waste; however, the kraft process gave the best strength properties. In general, the strength of the agave waste pulps was rather poor in comparison to wood and other agro-based pulps; however, the tear strength was relatively high. This result is typical of poorly bonded sheets and may be due to the coarseness of the agave fibers and/or loss of hemicelluloses in the steaming process for the tequila production. Fungal treatment of the agave waste with Ceriporiopsis subvermispora reduced the energy consumption for mechanical refining but gave biomechanical pulps with inferior strength properties. The blue agave chemical pulps should be suitable for blending with softwood kraft pulps for publication grade paper.

  2. Chemical and sensory characterization of orange (Citrus sinensis) pulp,a by-product of orange juice processing using gas-chromatography-olfactometry

    USDA-ARS?s Scientific Manuscript database

    Volatile composition of commercial orange pulp (from Brazil and Florida, U.S.A.) were analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-Olfactometry (GC-O). In both samples 72 volatiles were detected, of which 58 were identified. Odor-active compounds with high frequency of detection (...

  3. Survey of receiving-water environmental impacts associated with discharges from pulp mills; 1: Mill characteristics, receiving-water chemical profiles and lab toxicity tests

    SciTech Connect

    Robinson, R.D. . Dept. of Environmental Biology); Carey, J.H. . Rivers Research Branch); Solomon, K.R. ); Smith, I.R. . Water Resources Branch); Servos, M.R.; Munkittrick, K.R. . Great Lakes Lab. for Fisheries and Aquatic Sciences)

    1994-07-01

    This survey examined the relationship between environmental responses at pulp mill sites and the pulping process, effluent treatment, and bleaching technology used by pulp mills. This manuscript is the first in a series of four; it reviews the location and operating characteristics of mills included in the survey and provides background information on water chemistry that is relevant to the other components of the survey. In addition, lab 7-d toxicity tests of receiving water were conducted using fathead minnows (Pimephales promelas) and the cladoceran Ceriodaphnia dubia with water samples collected upstream and downstream of effluent discharges at 11 Canadian pulp and paper mills; these samples were collected at the same time as fish surveys were conducted. Survival of fathead minnow larvae was significantly reduced at four of the 11 downstream sites. Ceriodaphnia reproduction was significantly higher at six of the 11 downstream sites and significantly lower at two downstream sites. There were no significant effects on fathead minnow larva growth or adult Ceriodaphnia survival at any of the examined downstream sites. Negative effects in the toxicity tests were generally associated with the low dilution discharge of primary treated effluent with a previous history of acute toxicity. Fathead minnow and Ceriodaphnia tests were generally correlated with historical data on benthic macroinvertebrate community responses. Neither toxicity test predicted the physiological changes in wild fish that are presented in accompanying papers.

  4. Ethanol determination in frozen fruit pulps: an application of quantitative nuclear magnetic resonance.

    PubMed

    da Silva Nunes, Wilian; de Oliveira, Caroline Silva; Alcantara, Glaucia Braz

    2016-04-01

    This study reports the chemical composition of five types of industrial frozen fruit pulps (acerola, cashew, grape, passion fruit and pineapple fruit pulps) and compares them with homemade pulps at two different stages of ripening. The fruit pulps were characterized by analyzing their metabolic profiles and determining their ethanol content using quantitative Nuclear Magnetic Resonance (qNMR). In addition, principal component analysis (PCA) was applied to extract more information from the NMR data. We detected ethanol in all industrial and homemade pulps; and acetic acid in cashew, grape and passion fruit industrial and homemade pulps. The ethanol content in some industrial pulps is above the level recommended by regulatory agencies and is near the levels of some post-ripened homemade pulps. This study demonstrates that qNMR can be used to rapidly detect ethanol content in frozen fruit pulps and food derivatives. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Pulp stones: a review.

    PubMed

    Goga, R; Chandler, N P; Oginni, A O

    2008-06-01

    Pulp stones are a frequent finding on bitewing and periapical radiographs but receive relatively little attention in textbooks. A review of the literature was therefore performed, initially using the PubMed database and beginning the search with 'pulp calcifications' and 'pulp stones'. Each term provided more than 400 references, many of which related to pulp calcification in general rather than pulp stones, and focussed largely on the problems these changes presented to clinicians. A manual search using references from this source was carried out. Contemporary textbooks in endodontology were also consulted, and an historic perspective gained from a number of older books and references. The factors involved in the development of the pulp stones are largely unknown. Further research may determine the reasons for their formation, but with current endodontic instruments and techniques this is unlikely to alter their relevance to clinicians.

  6. Kraft pulp from budworm-infested jack pine

    Treesearch

    J. Y. Zhu; Gary C. Myers

    2006-01-01

    This study evaluated the quality of kraft pulp from bud-worm-infested jack pine. The logs were classified as merchantable live, suspect, or merchantable dead. Raw materials were evaluated through visual inspection, analysis of the chemical composition, SilviScan measurement of the density, and measurement of the tracheid length. Unbleached pulps were then refined using...

  7. Use of laccase in pulp and paper industry.

    PubMed

    Virk, Antar Puneet; Sharma, Prince; Capalash, Neena

    2012-01-01

    Laccase, through its versatile mode of action, has the potential to revolutionize the pulping and paper making industry. It not only plays a role in the delignification and brightening of the pulp but has also been described for the removal of the lipophilic extractives responsible for pitch deposition from both wood and nonwood paper pulps. Laccases are capable of improving physical, chemical, as well as mechanical properties of pulp either by forming reactive radicals with lignin or by functionalizing lignocellulosic fibers. Laccases can also target the colored and toxic compounds released as effluents from various industries and render them nontoxic through its polymerization and depolymerization reactions. This article reviews the use of both fungal and bacterial laccases in improving pulp properties and bioremediation of pulp and paper mill effluents.

  8. Anthraquinone-A review of the rise and fall of a pulping catalyst

    Treesearch

    Peter W. Hart; Alan W. Rudie

    2014-01-01

    The application of anthraquinone (AQ) as a pulping catalyst has been well documented in scientific studies and mill applications. AQ is known to increase the rate of delignification, enabling a reduction in pulping time, temperature, or chemical charge and an increase in pulp yield. This review does not focus extensively on specific details of AQ use but rather on...

  9. Anthraquinone-A Review of the Rise and Fall of a Pulping Catalyst

    Treesearch

    Peter W. Hart; Alan W. Rudie

    2014-01-01

    The application of anthraquinone (AQ) as a pulping catalyst has been well documented in scientific studies and mill applications. AQ is known to increase the rate of delignification, enabling a reduction in pulping time, temperature, or chemical charge and an increase in pulp yield. Specific details of AQ use are not extensively reviewed in this work. The review...

  10. Healing process of dog dental pulp after pulpotomy and pulp covering with mineral trioxide aggregate or Portland cement.

    PubMed

    Holland, R; de Souza, V; Murata, S S; Nery, M J; Bernabé, P F; Otoboni Filho, J A; Dezan Júnior, E

    2001-01-01

    Considering several reports about the similarity between the chemical compositions of the mineral trioxide aggregate (MTA) and Portland cement (PC), the subject of this investigation was to analyze the behavior of dog dental pulp after pulpotomy and direct pulp protection with these materials. After pulpotomy, the pulp stumps of 26 roots of dog teeth were protected with MTA or PC. Sixty days after treatment, the animal was sacrificed and the specimens removed and prepared for histomorphological analysis. There was a complete tubular hard tissue bridge in almost all specimens. In conclusion, MTA and PC show similar comparative results when used in direct pulp protection after pulpotomy.

  11. An in vitro investigation of the mechanical-chemical and biological properties of calcium phosphate/calcium silicate/bismutite cement for dental pulp capping.

    PubMed

    Shen, Qingyi; Sun, Jiao; Wu, Jie; Liu, Changsheng; Chen, Fangping

    2010-07-01

    The properties of new calcium phosphate/calcium silicate/bismutite (CPCSBi) cement were compared with those of calcium hydroxide (CH) and Dycal cements in dental pulp-capping applications. CPCSBi is composed of hydroxyapatite, tetracalcium phosphate, bismutite, and calcium silicate, which was analyzed by SEM, FTIR, and XRD. The results of ion release from CPCSBi showed that the concentrations of Bi(3+), Ca(2+), PO4(2-), and Si(4+) increased with time in deionized water solutions. The setting time of CPCSBi and Dycal was 13 min 50 s and 2 min 25 s, respectively. There were no statistical differences in compressive strength and solubility between CPCSBi and Dycal (p > 0.05). The pH of CPCSBi (10.9) was lower than that of CH (11.6) and Dycal (12.5) after immersion for 24 h. Only slight cytotoxicity appeared for CPCSBi, whereas both CH and Dycal produced moderate discoloration and lysis. In antimicrobial tests against Sm, Av, La, and Sa, the antimicrobial potency of the CPCSBi was approximately 5-10 times greater than that of Dycal and CH groups. The dissoluble dentin matrix components (DDMCs) extracted from CPCSBi exposed to dentin powder demonstrated increased expression of dentin sialophosphoprotein (DSPP) and soteocalcin (OCN) dramatically in human pulp cells by RT-PCR. These results suggest that CPCSBi will be a good candidate for use as a dental pulp-capping agent in future. (c) 2010 Wiley Periodicals, Inc.

  12. Dry Kraft Pulping at Ambient Pressure for Cost Effective Energy Saving and Pollution Deduction

    SciTech Connect

    Yulin Deng; Art Ragauskas

    2012-08-28

    Sponsored by the DOE Industrial Energy Efficiency Grand Challenge program, our research team at the Georgia Institute of Technology conducted laboratory studies and confirmed the concept of making wood pulp using a dry pulping technology. This technology is a new process different from any prior pulping technology used in Kraft and CTMP pulping. Three different kinds of dry pulping methods were investigated. (a) Dry Pulping at Atmospheric Pressure: The first one is to dry and bake the pretreated woodchips in a conventional oven at atmospheric pressure without the use of a catalyst. (b) Dry Pulping at Reduced Pressure: The second method is to dry the pretreated woodchips first in a vacuum oven in the presence of anthraquinone (AQ) as a pulping catalyst, followed by baking at elevated temperature. (c) Liquid Free Chemical Pulping, LFCP. The third method is to first remove the free water of pretreated woodchips, followed by dry pulping using a conventional Kraft pulping digester with AQ and triton as additives. Method one: Experimental results indicated that Dry Pulping at Atmospheric Pressure could produce pulp with higher brightness and lower bulk than conventional Kraft pulp. However, tensile strength of the acquired pulp is much lower than traditional Kraft pulp, and their Kappa number and energy consumption are higher than conventional Kraft pulp. By fully analyzing the results, we concluded that wood fibers might be damaged during the drying process at elevated temperature. The main reason for wood fiber damage is that a long drying time was used during evaporation of water from the woodchips. This resulted in an un-uniform reaction condition on the woodchips: the outside layer of the woodchips was over reacted while inside the woodchips did not reacted at all. To solve this problem, dry pulping at reduced pressure was investigated. Method two: To achieve uniform reaction throughout the entire reaction system, the water inside the pretreated woodchips was

  13. Paper Pulp Panoply.

    ERIC Educational Resources Information Center

    Marque, Margo E.

    1999-01-01

    Explains that creating paper-pulp bowls is designed to acquaint students with the beginning vocabulary and finger dexterity needed to sculpt clay. Describes the process of making paper-pulp bowls and identifies important vocabulary words. Provides directions for making paper bowl forms and lists the materials. (CMK)

  14. Paper Pulp Panoply.

    ERIC Educational Resources Information Center

    Marque, Margo E.

    1999-01-01

    Explains that creating paper-pulp bowls is designed to acquaint students with the beginning vocabulary and finger dexterity needed to sculpt clay. Describes the process of making paper-pulp bowls and identifies important vocabulary words. Provides directions for making paper bowl forms and lists the materials. (CMK)

  15. Catalysis: A Potential Alternative to Kraft Pulping

    Treesearch

    Alan W. Rudie; Peter W. Hart

    2014-01-01

    A thorough analysis of the kraft pulping process makes it obvious why it has dominated for over a century as an industrial process with no replacement in sight. It uses low cost raw materials, collects and regenerates over 90% of the chemicals needed in the process, is indifferent to wood raw material and good at preserving the cellulose portion of the wood which is...

  16. Arundo donax L. reed: new perspectives for pulping and bleaching. 5. Ozone-based TCF bleaching of organosolv pulps.

    PubMed

    Shatalov, A A; Pereira, H

    2008-02-01

    Three selected alkali-based organosolv pulps (alkali-sulfite-anthraquinone-methanol (ASAM), alkali-anthraquinone-methanol (organocell) and ethanol-soda) from agrofibre crop giant reed (Arundo donax L.) were bleached by an ozone-based TCF (totally chlorine- free) bleaching sequence AZE(R)QP (where A is an acidic pulp pre-treatment, Z is an ozone stage, (E(R)) is an alkaline extraction in the presence of reducing agent, Q is a pulp chelating, P is a hydrogen peroxide stage) without oxygen pre-bleaching, and compared with a conventional kraft pulp used as a reference. The different response on bleaching conditions within each bleaching stage was noted for all tested pulps. The pulp bleachability, in terms of brightness improvement or lignin removal per unit of applied chemicals, was found higher for the organocell pulp. The ASAM and ethanol-soda pulps showed the highest bleaching selectivity, expressed by viscosity loss per unit of lignin removed or brightness improved. The overall bleaching results of organosolv pulps were superior to kraft.

  17. Final Technical Report Steam Cycle Washer for Unbleached Pulp

    SciTech Connect

    Starkey, Yvonne; Salminen, Reijo; Karlsnes, Andy

    2008-09-22

    Project Abstract for “Steam Cycle Washer for Unbleached Pulp” When completed, the patented SC Washer will provide an innovative, energy efficient demonstration project to wash unbleached pulp using a pressure vessel charged with steam. The Port Townsend Paper Corporation’s pulp mill in Port Townsend, WA was initially selected as the host site for conducting the demonstration of the SCW. Due to 2006 and 2007 delays in the project caused by issues with 21st Century Pulp & Paper, the developer of the SCW, and the 2007 bankruptcy proceedings and subsequent restructuring at Port Townsend Paper, the mill can no longer serve as a host site. An alternate host site is now being sought to complete the commercial demonstration of the Steam Cycle Washer for Unbleached Pulp. Additionally, estimated costs to complete the project have more than doubled since the initial estimates for the project were completed in 2002. Additional grant funding from DOE was sought and in July, 2008 the additional DOE funds were procured under a new DOE award, DE-PS36-08GO98014 issued to INL. Once the new host site is secured the completion of the project will begin under the management of INL. Future progress reports and milestone tracking will be completed under requirements of new DOE Award Number DE-PS36-08GO98014. The following are excerpts from the project Peer Review completed in 2006. They describe the project in some detail. Additional information can be found by reviewing DOE Award Number: DE-PS36-08GO98014. 5. Statement of Problem and Technical Barriers: The chemical pulping industry is one of the major users of fresh water in the United States. On average the industry uses over 80 tons of water to produce one ton of pulp, some states use up to 50% more (Washington 120 and Wisconsin 140). In order to process one ton of pulp using 80 tons of process water, a large amount of: • energy is used in process heat and • power is required for pumping the large volume of pulp slurries

  18. Pulp, paper, and paperboard industry -- Background information for promulgated air emission standards: Manufacturing processes at kraft, sulfite, soda, semi-chemical, mechanical, and secondary and non-wood fiber mills. Final report

    SciTech Connect

    1997-10-01

    National emission standards for hazardous air pollutants (NESHAP) are being promulgated for the pulp and paper industry under authority of Section 112(d) of the Clean Air Act as amended in 1990. This background information document provides technical information and analyses used in the development of the promulgated pulp and paper NESHAP, and contains responses to comments from the proposed rule. This document covers air emission controls for wood pulping and bleaching processes at pulp mills and integrated mills (i.e., mills that combine on-site production of both pulp and paper).

  19. Pollution prevention in the pulp and paper industry

    SciTech Connect

    Jenkins, P.G.

    1995-09-01

    Probably no other industry has made as much progress as the kraft pulp and paper industry in reclaiming waste products. About half of the wood used in making pulp is cellulose; the reclamation of the other ingredients in the wood constitutes a continuing evolution of pollution prevention and economic success. The by-products of chemical pulping include turpentine used in the paint industry, lignosulfonates used as surfactants and dispersants, ``tall oil`` used in chemical manufacturing, yeast, vanillin, acetic acid, activated carbon, and alcohol. Sulfamic turpentine recovered in the kraft process is used to manufacture pine oil, dimethyl sulfoxide (DMSO), and other useful chemical products. In addition, the noncellulose portion of the wood is used to provide energy for the pulping process through the combustion of concentrated black liquor. Over 75% of the pulp produced in the US is manufactured using the kraft process. Because of the predominance of the kraft process, the remainder of this section will address pollution prevention methods for kraft pulp and paper mills. Some of these techniques may be applicable or adaptable to other pulping processes, especially sulfite mills. The major steps in the kraft process are described, followed by a discussion of major wastestreams, and proven pollution prevention methods for each of these steps.

  20. DENTAL PULP TISSUE ENGINEERING

    PubMed Central

    Demarco, FF; Conde, MCM; Cavalcanti, B; Casagrande, L; Sakai, V; Nör, JE

    2013-01-01

    Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research. PMID:21519641

  1. Novel Pulping Technology: Directed Green Liquor Utilization (D-GLU) Pulping

    SciTech Connect

    Lucian A. Lucia

    2005-11-15

    The general objectives of this new project are the same as those described in the original proposal. Conventional kraft pulping technologies will be modified for significant improvements in pulp production, such as strength, bleachability, and yield by using green liquor, a naturally high, kraft mill-derived sulfidity source. Although split white liquor sulfidity and other high sulfidity procedures have the promise of addressing several of the latter important economic needs of pulp mills, they require considerable engineering/capital retrofits, redesigned production methods, and thus add to overall mill expenditures. Green liquor use, however, possesses the required high sulfidity to obtain in general the benefits attributable to higher sulfidity cooking, without the required capital constraints for implementation. Before introduction of green liquor in our industrial operations, a stronger understanding of its fundamental chemical interaction with the lignin and carbohydrates in US hardwood and softwoods must be obtained. In addition, its effect on bleachability, enhancement of pulp properties, and influence on the overall energy and recovery of the mill requires further exploration before the process witnesses widespread mill use in North America. Thus, proof of principle will be accomplished in this work and the consequent effect of green liquor and other high sulfide sources on the pulping and bleaching operations will be explored for US kraft mills. The first year of this project will generate the pertinent information to validate its ability for implementation in US pulping operations, whereas year two will continue this work while proceeding to analyze pulp bleachability and final pulp/paper properties and develop a general economic and feasibility analysis for its eventual implementation in North America.

  2. High-energy electron irradiation of annual plants (bagasse) for an efficient production of chemi-mechanical pulp fibers

    NASA Astrophysics Data System (ADS)

    Pathak, Shailesh; Ray, A. K.; Großmann, Harald; Kleinert, Rene

    2015-12-01

    The paper industry is one of the largest consumers of energy and energy consumption has been increased several times in last few decades. Bagasse chemical pulping has very low yield about 45-55% and also generates high pollution load in the effluent as compared to mechanical pulping, g. Thermo-mechanical pulp (TMP). On the other hand,-->e.g. thermo-mechanical pulp (TMP). On the other hand, the specific energy consumption is very high for TMP pulps. ETMP (Energy efficient Thermo-Mechanical Pulping) or ECTMP (Energy efficient Chemi-Thermo Mechanical Pulping) is an innovative idea for reducing the energy demand in TMP refining. In the present investigation, energy efficient mechanical pulping potential of bagasse was studied using TMP, CTMP and ECTMP pulping methodology with electron irradiation pretreatment. It is evident from the results that more than 50% energy saving potential of irradiation pre-treatment was achieved.

  3. Assessment of electrochemical and chemical coagulation as post-treatment for the effluents of a UASB reactor treating cellulose pulp mill wastewater.

    PubMed

    Buzzini, A P; Motheo, A J; Pires, E C

    2005-01-01

    This paper presents results from exploratory experiments to test the technical feasibility of electrolytic treatment and coagulation followed by flocculation and sedimentation as post-treatment for the effluent of an UASB reactor treating simulated wastewater from an unbleached Kraft pulp mill. The electrolytic treatment provided up to 67% removal of the remaining COD and 98% of color removal. To achieve these efficiencies the energy consumption ranged from 14 Wh x l(-1) to 20 Wh x l(-1). The coagulation-flocculation treatment followed by settling required 350-400 mg x l(-1) of aluminium sulfate. The addition of a high molecular weight cationic polymer enhanced both COD and color removal. Both post-treatment processes are technically feasible.

  4. Biogas generation apple pulp.

    PubMed

    Llaneza Coalla, H; Blanco Fernández, J M; Morís Morán, M A; López Bobo, M R

    2009-09-01

    In view of the pressing problem that appears in our region (Asturias, north of Spain) with the residues from the cider production, it was decided to test this kind of material as a co-substrate joint with slaughterhouse waste in a laboratory unit. The anaerobic digestion of apple pulp was investigated for biogas production. This paper presents the results where apple pulp was co-digested with slaughterhouse waste (pig intestine and bovine stomach content) in a biogas laboratory unit (10 l CSTR reactor). The production of biogas has reached very satisfactory values during the whole test (0.8m(3)kg(-1)OTS), verifying that the process is kept in stable conditions of pH (near 8.0), and the volatile fatty acids was always underneath 3000 mg/l, when the pulp amount was lower than 100g in mesophilic conditions. The fat concentration into the digester remained always below the value that causes inhibition of the methanogenic bacteria, 500 mg/l. Finally, methane concentration (77-80%) and H(2)S concentration (400 ppm) in the biogas, they were similar to those obtained when the test was run out in the absence of apple pulp. The process efficiency with respect to COD removal was high, near 80% of the total COD. Finally, inhibitory effects of methanogenic bacteria were observed when pulp concentration was around 10% in the input material.

  5. Influence of kraft pulping on carboxylate content of softwood kraft pulps

    Treesearch

    Zheng Dang; Thomas Elder; Arthur J. Ragauskas

    2006-01-01

    This study characterizes changes in fiber charge, which is the carboxylate content of fibers, for two sets of kraft pulps: (1) conventional laboratory cooked loblolly pine kraft pulps and (2) conventional pulping (CK) versus low solids pulping (LS) pulps. Laboratory kraft pulping of loblolly pine was carried out to study the influence of pulping conditions, including...

  6. Dental Pulp Testing: A Review

    PubMed Central

    Chen, Eugene; Abbott, Paul V.

    2009-01-01

    Dental pulp testing is a useful and essential diagnostic aid in endodontics. Pulp sensibility tests include thermal and electric tests, which extrapolate pulp health from sensory response. Whilst pulp sensibility tests are the most commonly used in clinical practice, they are not without limitations and shortcomings. Pulp vitality tests attempt to examine the presence of pulp blood flow, as this is viewed as a better measure of true health than sensibility. Laser Doppler flowmetry and pulse oximetry are examples of vitality tests. Whilst the prospect is promising, there are still many practical issues that need to be addressed before vitality tests can replace sensibility tests as the standard clinical pulp diagnostic test. With all pulp tests, the results need to be carefully interpreted and closely scrutinised as false results can lead to misdiagnosis which can then lead to incorrect, inappropriate, or unnecessary treatment. PMID:20339575

  7. Inter-laboratory comparisons of hexenuronic acid measurements in kraft eucalyptus pulps using a UV-Vis spectroscopic method

    Treesearch

    J.Y. Zhu; H.F Zhou; Chai X.S.; Donna Johannes; Richard Pope; Cristina Valls; M. Blanca Roncero

    2014-01-01

    An inter-laboratory comparison of a UV-Vis spectroscopic method (TAPPI T 282 om-13 “Hexeneuronic acid content of chemical pulp”) for hexeneuronic acid measurements was conducted using three eucalyptus kraft pulps. The pulp samples were produced in a laboratory at kappa numbers of approximately 14, 20, and 35. The hexeneuronic acid contents of the three pulps were...

  8. Inference of chemicals that cause biological effects in treated pulp and paper mill effluent using gene expression in caged fathead minnows

    EPA Science Inventory

    Analytical chemistry techniques can identify chemicals present in the waters of the Great Lakes areas of concern, however it remains a challenge to identify those chemicals or classes of chemicals that actually cause adverse effects. Use of caged fathead minnows (Pimephales prome...

  9. Inference of chemicals that cause biological effects in treated pulp and paper mill effluent using gene expression in caged fathead minnows

    EPA Science Inventory

    Analytical chemistry techniques can identify chemicals present in the waters of the Great Lakes areas of concern, however it remains a challenge to identify those chemicals or classes of chemicals that actually cause adverse effects. Use of caged fathead minnows (Pimephales prome...

  10. [Application of enzymes in pulp and paper industry].

    PubMed

    Lin, Ying

    2014-01-01

    The application of enzymes has a high potential in the pulp and paper industry to improve the economics of the paper production process and to achieve, at the same time, a reduced environmental burden. Specific enzymes contribute to reduce the amount of chemicals, water and energy in various processes. This review is aimed at presenting the latest progresses of applying enzymes in bio-pulping, bio-bleaching, bio-deinking, enzymatic control of pitch and enzymatic modification of fibers.

  11. [Coffee hulls and pulp. XII. Effect of storage of coffee pulp on its nutritive value for calves].

    PubMed

    Cabezas, M T; Estrada, E; Murillo, B; González, J M; Bressani, R

    1976-06-01

    Coffee pulp, dehydrated and stored for 7, 13 and 17 months or ensiled for 4, 10 and 14 months, was studied in calves with a rapid growing rate. Storage of dehydrated coffee pulp did not affect its chemical composition, but ensiling reduced crude fiber and increased its nitrogen free extract content after 10 and 14 months. Three growth trials were carried out with Holstein calves averaging 95 kg in the first and second trials, and 130 kg in the third. Eighteen calves were used in the first trial and 24 in each of the other two. In each trial the animals were divided into three equal groups and randomly assigned to one of the following treatments: control, which contained 48% cottonseed hulls, and the other two, with 30% dehydrated coffee pulp or 30% ensiled coffee pulp. Basically, the difference between trials consisted in the time of storage or ensiling of coffee pulp. In all trials, weight gains of calves fed coffee pulp (1.00, 0.90 and 0.98 kg/day, and 1.06, 0.94 and 1.08 kg/day, respectively) were significantly lower (P less than 0.05) than the weight gains induced by the control ration (1.21, 1.08 and 1.19 kg/day). Feed intake was also lower, but feed conversion ratio was higher for those rations containing coffee pulp. Calf performance was better with ensiled than with deydrated coffee pulp, particularly in the third trial, where the differences in weight gains were significantly higher (P less than 0.05). It is concluded that storage time does not change nutritive value of coffee pulp; and the ensiling is an adequate process for storing pulp during coffee harvesting, and, possibly also, for improving its nutritive value.

  12. Indirect pulp capping in young patients: immunohistological study of pulp-dentin complex.

    PubMed

    Ţuculină, Mihaela Jana; Răescu, Mihaela; Dascălu, Ionela Teodora; Popescu, Mihaela; Andreescu, Claudia Florina; Dăguci, C; Cumpătă, C N; Nimigean, Vanda Roxana; Baniţă, Ileana Monica

    2013-01-01

    Indirect capping is a complex therapy exclusively needed in deep cavities that provides, using biomaterials, a disinfection of the dentinary sore and seals the dentinary tubules, protects the pulp of physical mechanisms and chemical agents and stimulates the mechanisms that produce new dentin. Following this idea, we studied the histological changes in the dental pulp tissue and also the specific immunohistochemical response in various structures when an indirect capping technique was used. We used special histological techniques followed by classical staining or by immunohistochemical reaction in order to assess the odontoblastic, and the vascular reaction. The immunohistochemical study allows us to evaluate the changes in the pulp-dentin complex, as the result of the changes in the dentinal tubules permeability and the biological reactions at this level.

  13. Manganese peroxidase, produced by Trametes versicolor during pulp bleaching, demethylates and delignifies kraft pulp

    SciTech Connect

    Paice, M.G.; Reid, I.D.; Bourbonnais, R.; Archibald, F.S.; Jurasek, L. )

    1993-01-01

    The white rot fungus Trametes (Coriolus) versicolor delignifies and bleaches kraft pulp. However, the process is slow compared with chemical bleaching and the cellulose is also attacked. This study attempts to determine the enzymology of fungal delignification and then applies the relevant enzymes directly to the pulp. Lignin peroxidase and manganese peroxidase (MnP) have both been implicated in lignin biodegradations. However, the researchers show that MnP is the critical enzyme. It is produced by bleaching cultures of T. versicolor; its peak production occurs at the same time as the maximum rate of fungal culture bleaching, and the manganese-and peroxide-dependent demethylation and delignification of kraft pulp occurs in vitro. 50 refs., 4 figs., 7 tabs.

  14. High-yield pulping effluent treatment technologies. Final report

    SciTech Connect

    Su, W.X.; Hsieh, J.S.

    1993-03-01

    The objective of this report is to examine the high-yield (mechanical) pulp processes with respect to environmental issues affected by the discharge of their waste streams. Various statistics are given that support the view that high-yield pulping processes will have major growth in the US regions where pulp mills are located, and sites for projects in the development phase are indicated. Conventional and innovative effluent-treatment technologies applicable to these processes are reviewed. The different types of mechanical pulping or high-yield processes are explained, and the chemical additives are discussed. The important relationship between pulp yield and measure of BOD in the effluent is graphically presented. Effluent contaminants are identified, along with other important characteristics of the streams. Current and proposed environmental limitations specifically related to mechanical pulp production are reviewed. Conventional and innovative effluent-treatment technologies are discussed, along with their principle applications, uses, advantages, and disadvantages. Sludge management and disposal techniques become an intimate part of the treatment of waste streams. The conclusion is made that conventional technologies can successfully treat effluent streams under current waste-water discharge limitations, but these systems may not be adequate when stricter standards are imposed. At present, the most important issue in the treatment of pulp-mill waste is the management and disposal of the resultant sludge.

  15. Alkaline peroxide mechanical pulping of wheat straw with enzyme treatment.

    PubMed

    Zhao, Jian; Li, Xuezhi; Qu, Yinbo; Gao, Peiji

    2004-01-01

    Alkaline peroxide mechanical pulping (APMP) of wheat straw with enzyme treatment was studied. Instead of direct enzyme pretreatment on wheat straw, an alternative treatment method was used, in which coarse pulps from refiner defibrated wheat straw rather than wheat straw were pretreated with a crude enzyme containing mainly xylanase, then impregnated with alkaline H2O2 solution and further refined. The optimum conditions of enzyme treatment were xylanase dosage of 10-15 IU/g of oven-dried wheat straw, 90 min, 50-60 degrees C, pulp consistency of 5-10%, and initial pH of 5.0, and those for chemical impregnation were 6% NaOH, 70-80 degrees C, 60-90 min, and 4 to 5% H2O2. Enzyme treatment improved pulpability of wheat straw by the APMP process, and final pulp quality such as brightness, breaking length, and burst index of pulp. Pulp from the APMP process with enzyme treatment could be bleached to a brightness of 70.5% ISO by two-stage H2O2 bleaching sequence with only 4% H2O2, and breaking length of the bleach pulp reached 4470 m

  16. Biomechanical pulping of kenaf

    Treesearch

    Aziz Ahmed; Masood Akhtar; Gary C. Myers; Gary M. Scott

    1999-01-01

    The objective of this study was to investigate the effect of fungal pretreatment of whole kenaf prior to refining on refiner electrical energy consumption, paper strength, and optical properties. We also explored the suitability of whole kenaf biomechanical pulp for making newsprint in terms of ISO brightness and strength properties. Kenaf was sterilized by autoclaving...

  17. Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

    PubMed Central

    Zhang, Daolei; Li, Xuezhi; Wang, Meimei; Ye, Yanxin; Du, Jian; Lu, Xianqin; Zhao, Jian

    2016-01-01

    Xylanase is commonly applied in pulp and paper industries to ease cost-related and environmental pressures. The effect of xylanase treatment on pulp bleaching is well-established, however, few studies were conducted on the effects of xylanase treatment in pulp yellowing, especially the mechanism of pulp yellowing inhibition by xylanase treatment. In this study, pure xylanase (EC 3.2.1.8) was applied to treat wheat straw chemical pulp (CP) and poplar chemi-thermo-mechanical pulp (CTMP) to determine their effects on pulp brightness and on light- and heat-induced yellowing. The xylanase treatment decreased the post-color number of the pulps during light- and heat-induced yellowing. However, differences were observed in the yellowing inhibition between the wheat straw CP and poplar CTMP. The changes in chemical components of pulps after the xylanase treatment, for example, lignin, hemicellulose, and HexA contents, and analysis of UV–vis absorption spectra and Fourier transform infrared-attenuated total reflectance spectrum were used to explore the pulp yellowing inhibition causes by the xylanase treatment. PMID:27917912

  18. Catalysis: A Potential Alternative to Kraft Pulping

    Treesearch

    Alan W. Rudie; Peter W. Hart

    2014-01-01

    A thorough analysis of the kraft pulping process makes it obvious why it has dominated for over a century as an industrial process with no replacement in sight. It uses low-cost raw materials; collects and regenerates over 90% of the chemicals needed in the process; and is indifferent to wood raw material and good at preserving the cellulose portion of the wood, the...

  19. Role of angiogenesis in endodontics: contributions of stem cells and proangiogenic and antiangiogenic factors to dental pulp regeneration.

    PubMed

    Saghiri, Mohammad Ali; Asatourian, Armen; Sorenson, Christine M; Sheibani, Nader

    2015-06-01

    Dental pulp regeneration is a part of regenerative endodontics, which includes isolation, propagation, and re-transplantation of stem cells inside the prepared root canal space. The formation of new blood vessels through angiogenesis is mandatory to increase the survival rate of re-transplanted tissues. Angiogenesis is defined as the formation of new blood vessels from preexisting capillaries, which has great importance in pulp regeneration and homeostasis. Here the contribution of human dental pulp stem cells and proangiogenic and antiangiogenic factors to angiogenesis process and regeneration of dental pulp is reviewed. A search was performed on the role of angiogenesis in dental pulp regeneration from January 2005 through April 2014. The recent aspects of the relationship between angiogenesis, human dental pulp stem cells, and proangiogenic and antiangiogenic factors in regeneration of dental pulp were assessed. Many studies have indicated an intimate relationship between angiogenesis and dental pulp regeneration. The contribution of stem cells and mechanical and chemical factors to dental pulp regeneration has been previously discussed. Angiogenesis is an indispensable process during dental pulp regeneration. The survival of inflamed vital pulp and engineered transplanted pulp tissue are closely linked to the process of angiogenesis at sites of application. However, the detailed regulatory mechanisms involved in initiation and progression of angiogenesis in pulp tissue require investigation. Published by Elsevier Inc.

  20. Role of Angiogenesis in Endodontics: Contributions of Stem Cells and Proangiogenic and Antiangiogenic Factors to Dental Pulp Regeneration

    PubMed Central

    Saghiri, Mohammad Ali; Asatourian, Armen; Sorenson, Christine M.; Sheibani, Nader

    2016-01-01

    Introduction Dental pulp regeneration is a part of regenerative endodontics, which includes isolation, propagation, and re-transplantation of stem cells inside the prepared root canal space. The formation of new blood vessels through angiogenesis is mandatory to increase the survival rate of re-transplanted tissues. Angiogenesis is defined as the formation of new blood vessels from preexisting capillaries, which has great importance in pulp regeneration and homeostasis. Here the contribution of human dental pulp stem cells and proangiogenic and antiangiogenic factors to angiogenesis process and regeneration of dental pulp is reviewed. Methods A search was performed on the role of angiogenesis in dental pulp regeneration from January 2005 through April 2014. The recent aspects of the relationship between angiogenesis, human dental pulp stem cells, and proangiogenic and antiangiogenic factors in regeneration of dental pulp were assessed. Results Many studies have indicated an intimate relationship between angiogenesis and dental pulp regeneration. The contribution of stem cells and mechanical and chemical factors to dental pulp regeneration has been previously discussed. Conclusions Angiogenesis is an indispensable process during dental pulp regeneration. The survival of inflamed vital pulp and engineered transplanted pulp tissue are closely linked to the process of angiogenesis at sites of application. However, the detailed regulatory mechanisms involved in initiation and progression of angiogenesis in pulp tissue require investigation. PMID:25649306

  1. Obtaining value prior to pulping with diethyl oxalate and oxalic acid

    Treesearch

    W.R. Kenealy; E. Horn; C.J. Houtman; J. Laplaza; T.W. Jeffries

    2007-01-01

    Pulp and paper are converted to paper products with yields of paper dependent on the wood and the process used. Even with high yield pulps there are conversion losses and with chemical pulps the yields approach 50%. The portions of the wood that do not provide product are either combusted to generate power and steam or incur a cost in waste water treatment. Value prior...

  2. Understanding the Nature and Reactivity of Residual Lignin for Improved Pulping and Bleaching Efficiency

    SciTech Connect

    Yuan-Zong Lai

    2001-11-30

    One of the most formidable challenges in kraft pulping to produce bleached chemical pulps is how to effectively remove the last 5-10% of lignin while maintaining the fiber quality. To avoid a severe fiber degradation, kraft pulping is usually terminated in the 25-30 kappa number range and then followed by an elementally chlorine free (ECF) or a totally chlorine free (TCF) bleaching sequence to reduce the environmental impacts.

  3. Conversion of henequen pulp to microbial biomass by submerged fermentation

    SciTech Connect

    Blancas, A.; Alpizar, L.; Larios, G.; Saval, S.; Huitron, C.

    1982-01-01

    Mexico has cellulosic by-products that could be developed as renewable food sources for animal consumption. Sugarcane bagasse and henequen pulp are the most important of these materials because they are abundant, cheap, renewable, and nontoxic, in addition to being underutilized. A significant research and development effort has centered on the production of single-cell protein from sugarcane begasse. Nevertheless, there are no large-scale processes that utilize this substrate as a source of carbon, probably because of the extensive physical or chemical pretreatment that is needed. Henequen pulp is a by-product which is obtained in large amounts in southeastern Mexico in the process of removing fibers from the leaves of agave (sisal). A group has been working on a fermentative process that will increase the protein content of the henequen pulp by microbial conversion. The primary aim is to carry out the conversion without chemical pretreatment of the substrate and without a separation step for cells and residual substrate. A gram-negative cellulolytic bacteria has been isolated which grows well on microcrystalline cellulose, pectin, and xylane and it is able to convert an appreciable fraction of henequen pulp to microbial biomass. In this article, some results on the effect of substrate and nitrogen source concentration, on the protein enrichment of the henequen pulp, as well as the content of essential amino acids of fermented henequen pulp are presented. 4 figures.

  4. Dental pulp stem cells

    PubMed Central

    Ashri, Nahid Y.; Ajlan, Sumaiah A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from their relative accessibility and pleasant handling properties. The purpose of this article is to review the biological principles of periodontal tissue engineering, along with the challenges facing the development of a consistent and clinically relevant tissue regeneration platform. This article includes an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors. PMID:26620980

  5. Timber Bamboo Pulp

    Treesearch

    Troy Runge; Carl Houtman; Alberto Negri; Jackie Heinricher

    2013-01-01

    Fast-growing biomass, such as bamboo, has the potential to serve an important future role in the pulp and paper industry with potential to both lower resource costs and improve a product’s sustainability. Moso bamboo is particularly interesting due to its fast growth and size, which allows it to be handled and chipped similarly to wood resources. In this study, we will...

  6. Isolation and characterization of lignocellulose nanofibers from different wheat straw pulps.

    PubMed

    Sánchez, Rafael; Espinosa, Eduardo; Domínguez-Robles, Juan; Loaiza, Javier Mauricio; Rodríguez, Alejandro

    2016-11-01

    Wheat straw was cooked under different pulping processes: Soda (100°C, 7% NaOH, 150min), Kraft (170°C, 16% alkalinity, 25% sulfidity, 40min) and Organosolv (210°C, 60% ethanol, 60min). Once the pulps were obtained, lignocellulose nanofibers (LCNF) were isolated by mechanical process and TEMPO-mediated oxidation followed by a high pressure homogenization. After pulping process, the different pulps were characterized and its chemical composition was determined. The pulps characterization indicates that the Soda process is the process that, despite producing less delignification, retains much of the hemicelluloses in the pulp, being this content a key factor in the nanofibrillation process. Regarding the LCNF obtained by mechanical process, those nanofibers isolated from Organosolv wheat pulp (OWP) and Kraft wheat pulp (KWP) show low values for nanofibrillation yield, specific surface area and greater diameter. However, those nanofibers isolated from Soda wheat pulp (SWP) reach much higher values for these parameters and presents a diameter of 14nm, smaller than those obtained by TEMPO-mediated oxidation from OWP. Smaller diameters are generally obtained in TEMPO-oxidized LCNF. This work concludes that the lignin content does not affect greatly to obtain LCNF as does the hemicellulose content, so it is accurate to use a soft pulping process.

  7. Regenerative potential of dental pulp.

    PubMed

    Trope, Martin

    2008-07-01

    The regenerative potential of dental pulp, particularly in mature teeth, has been considered extremely limited. However, our improved understanding of pulpal inflammation and repair and improved dental materials and technologies make vital pulp therapy a viable alternative to root canal treatment. This article explores our knowledge in this regard and the future potential of saving or even regenerating the pulp as a routine dental procedure.

  8. Regenerative potential of dental pulp.

    PubMed

    Trope, Martin

    2008-01-01

    The regenerative potential of dental pulp, particularly in mature teeth, has been considered extremely limited. However, our improved understanding of pulpal inflammation and repair and improved dental materials and technologies make vital pulp therapy a viable alternative to root canal treatment. This article explores our knowledge in this regard and the future potential of saving or even regenerating the pulp as a routine dental procedure.

  9. Fourier transform Raman spectroscopic studies of a novel wood pulp bleaching system

    NASA Astrophysics Data System (ADS)

    Weinstock, Ira A.; Atalla, Rajai H.; Agarwal, Umesh P.; Minor, James L.; Petty, Chris

    1993-06-01

    The use of near-infrared (NIR) Fourier transform (FT) Raman spectroscopy for the study of lignocellulosic materials is discussed. An application utilizing NIR FT-Raman spectroscopy to study a novel chlorine-free process for the bleaching of wood pulps is presented in detail. The new process, still under development, entails the oxidation of residual lignin in wood pulps by vanadium-substituted polyoxometalates, and reoxidation of the reduced polyoxometalates by chlorine-free oxidants such as air, dioxygen, peroxides or ozone. Results from FT-Raman measurements of polyoxometalate-treated pulps are compared with those from chemical, spectroscopic and optical techniques commonly used in the pulp and paper industry.

  10. Polyoxometalate delignification of birch kraft pulp and effect on residual lignin

    Treesearch

    Biljana Bujanovic; Richard S. Reiner; Sally A. Ralph; Rajai H. Atalla

    2011-01-01

    To advance the understanding of delignification with polyoxometalates (POMs) that have been explored for use in bleaching of chemical pulps, the transformation of lignin during anaerobic treatment of birch kraft pulp with an equilibrated POM mixture composed of Na5(+2)[SiV1(-0.1)MoW10(+0.1)O

  11. De-pulping and Seed Separation from Tumba (Citrullus colocynthis) Fruit

    NASA Astrophysics Data System (ADS)

    Mudgal, Vishvambhar Dayal

    2017-07-01

    Tumba (Citrullus colocynthis) contains spongy pulp in which seeds are embedded unevenly. Seeds contain about 26% fats and 13% protein. The process of seed separation is highly time consuming and labour intensive. Two weeks are required to separate its seeds with traditional methods. The developed prototype, for separating tumba seeds, mainly consists of chopper, de-pulping screw, barrel assembly and seed separation unit. The de-pulping screw and barrel assembly was divided in two sections i.e. conveying (feeding zone) and compression sections (de-pulping zone). The performance of developed machine was evaluated at different screw speed in the range of 40-100 rpm. Maximum pulp removal efficiency of 78.1% was achieved with screw speed of 60 rpm. Seed separation from the pulp was carried out by adding different chemicals. Use of sodium hydroxide and potassium hydroxide produced seed separation up to 99%.

  12. Multivariate Analysis of Hemicelluloses in Bleached Kraft Pulp Using Infrared Spectroscopy.

    PubMed

    Chen, Zhiwen; Hu, Thomas Q; Jang, Ho Fan; Grant, Edward

    2016-12-01

    The hemicellulose composition of a pulp significantly affects its chemical and physical properties and thus represents an important process control variable. However, complicated steps of sample preparation make standard methods for the carbohydrate analysis of pulp samples, such as high performance liquid chromatography (HPLC), expensive and time-consuming. In contrast, pulp analysis by attenuated total internal reflection Fourier transform infrared spectroscopy (ATR FT-IR) requires little sample preparation. Here we show that ATR FT-IR with discrete wavelet transform (DWT) and standard normal variate (SNV) spectral preprocessing offers a convenient means for the qualitative and quantitative analysis of hemicelluloses in bleached kraft pulp and alkaline treated kraft pulp. The pulp samples investigated include bleached softwood kraft pulps, bleached hardwood kraft pulps, and their mixtures, as obtained from Canadian industry mills or blended in a lab, and bleached kraft pulp samples treated with 0-6% NaOH solutions. In the principal component analysis (PCA) of these spectra, we find the potential both to differentiate all pulps on the basis of hemicellulose compositions and to distinguish bleached hardwood pulps by species. Partial least squares (PLS) multivariate analysis gives a 0.442 wt% root mean square errors of prediction (RMSEP) for the prediction of xylan content and 0.233 wt% RMSEP for the prediction of mannan content. These data all support the idea that ATR FT-IR has a great potential to rapidly and accurately predict the content of xylan and mannan for bleached kraft pulps (softwood, hardwood, and their mixtures) in industry. However, the prediction of xylan and mannan concentrations presented a difficulty for pulp samples with modified cellulose crystalline structure.

  13. Influence of dimethyl formamide pulping of bagasse on pulp properties.

    PubMed

    Rezayati-Charani, P; Mohammadi-Rovshandeh, J; Hashemi, S J; Kazemi-Najafi, S

    2006-12-01

    Organosolv pulping of bagasse was conducted following a central composite design using a two-level factorial plan involving three pulping variables (temperature: 190-210 degrees C, time: 120-180 min, organic solvent charge: 40-60% dimethyl formamide). Responses of pulp properties (yield and holocellulose, alpha-cellulose, kappa number, ash and ethanol-dichloromethane extractives contents) and the pH of the resulting wastewater to the process variables were analyzed using statistical software (MINITAB). Main factor analysis revealed that optimum pulp has the following characteristics: 82.7% (yield), 92.9 (kappa number), 95.84% (holocellulose), 83.53% (alpha-cellulose), 1.403% (ash), 2.562% (ethanol-dichloromethane extractives contents) and 6.39 (pH). These results showed that acceptable properties of pulps could be gained at 200-210 degrees C for 150 min and 40-60% DMF. Based on these results, this method could be used for pulping of bagasse equivalent NSSC concerning high yield at a fixed kappa number. In addition, bagasse could be pulped with ease to approximately 55% yield with a kappa number approximately 31. Numerical analyses showed that cooking temperature had the greatest influence on properties of obtained pulps within the DMF concentrations and cooking time as cooking variables.

  14. Totally chlorine-free bleaching of flax pulp.

    PubMed

    Khristova, P; Tomkinson, J; Dimitrov, I; Valchev, I; Jones, G Lloyd

    2002-10-01

    Alkaline-sulphite Tamlin flax mill pulp of 34-41% brightness has been bleached with different totally chlorine-free (TCF) sequences (oxygen delignification, pressurised peroxide, peroxide without and with activator (TAED, tetraacetylethylenediamine) and with and without pre-treatment with ultrasound to 82% ISO brightness of the mill conventional CEH bleaching. Although the best results after oxygen delignification were obtained with pressurised peroxide, activated peroxide caused lower cellulose degradation and gave a higher pulp strength. The effects of temperature, retention time, chemical charge, TAED/peroxide ratio and alkalinity have been studied in order to maximise the brightness gain at lower viscosity loss. The chemistry and flexibility of TAED made it possible to activate the peroxide under conditions for which the peroxide alone is ineffective as a bleach, such as low alkalinity or low temperature. The presence of shives hindered the bleaching, but the bleached non-screened pulp was stronger than the screened one. Pre-treatment with ultrasound for 4 min of 1% pulp consistency gave 3-4% gain in ISO brightness for non-screened pulp and 2% for screened pulp and facilitated further delignification and peroxide bleaching.

  15. Oxalic acid pretreatment for mechanical pulping greatly improves paper strength while maintaining scattering power and reducing shives and triglycerides

    Treesearch

    Ross Swaney; Masood Akhtar; Eric Horn; Michael Lentz; John Klungness; Marc Sabourin

    2003-01-01

    In this paper we introduce a new technology based on a mild chemical pretreatment process prior to mechanical pulping. Chips are treated with a dilute solution of oxalic acid (OA) for only 10 minute at 130°C, in a typical example. The properties of the pulp produced by this OA process are quite different from those obtained via conventional chemical pretreatments,...

  16. Dissolving pulp industry : market trends

    Treesearch

    Irene. Durbak

    1993-01-01

    This report presents a worldwide overview of the dissolving pulp industry and highlights of this industry in Alaska. It describes trends in world markets and major end-use markets, with special emphasis on the manufacture and use of textile fibers in the United States. Figures and tables present data on production, consumption, and trade of dissolving pulp and the...

  17. [Dental pulp diseases. Ultramicroscopic studies].

    PubMed

    Conversini, A; Eramo, S; Manna, M G; Negri, P

    1998-12-01

    After the description of the anatomic and histologic aspects of the healthy dental pulp, stress is laid on pulpal pathologies and on the use of ultramicroscopic techniques to analyze the cytologic modifications in normal and pathologic dental pulp tissues. The results obtained are presented.

  18. The effect of pulping concentration treatment on the properties of microcrystalline cellulose powder obtained from waste paper.

    PubMed

    Okwonna, Okumneme O

    2013-10-15

    Microcrystalline cellulose (MCC) powder was isolated from three grades of waste paper: book, Groundwood/Newsprint and paperboard, through the processes of pulping and hydrolysis. Pulping treatment on these grades of waste paper was done using varying concentrations of caustic soda. Effects of the concentration of the pulping medium on the thermal and kinetic properties were investigated. Also determined were the effects of this on the physico-chemical properties. The chemical structure was characterized using an infrared spectroscopy (FTIR). Results showed these properties to be affected by the concentration of the pulping medium.

  19. Characterization of active paper packaging incorporated with ginger pulp oleoresin

    NASA Astrophysics Data System (ADS)

    Wiastuti, T.; Khasanah, L. U.; Atmaka Kawiji, W.; Manuhara, G. J.; Utami, R.

    2016-02-01

    Utilization of ginger pulp waste from herbal medicine and instant drinks industry in Indonesia currently used for fertilizer and fuel, whereas the ginger pulp still contains high oleoresin. Active paper packaging were developed incorporated with ginger pulp oleoresin (0%, 2%, 4%, and 6% w/w). Physical (thickness, tensile strength, and folding endurance, moisture content), sensory characteristics and antimicrobial activity of the active paper were evaluated. Selected active paper then were chemically characterized (functional groups). The additional of ginger pulp oleoresin levels are reduced tensile strength, folding endurance and sensory characteristic (color, texture and overall) and increased antimicrobial activity. Due to physical, sensory characteristic and antimicrobial activity, active paper with 2% ginger pulp oleoresin incorporation was selected. Characteristics of selected paper were 9.93% of water content; 0.81 mm of thickness; 0.54 N / mm of tensile strength; 0.30 of folding endurance; 8.43 mm inhibits the growth of Pseudomonas fluorescence and 27.86 mm inhibits the growth of Aspergillus niger (antimicrobial activity) and neutral preference response for sensory properties. For chemical characteristic, selected paper had OH functional group of ginger in 3422.83 cm-1 of wave number and indicated contain red ginger active compounds.

  20. Is Pulp Inflammation a Prerequisite for Pulp Healing and Regeneration?

    PubMed Central

    Goldberg, Michel; Njeh, Akram; Uzunoglu, Emel

    2015-01-01

    The importance of inflammation has been underestimated in pulpal healing, and in the past, it has been considered only as an undesirable effect. Associated with moderate inflammation, necrosis includes pyroptosis, apoptosis, and nemosis. There are now evidences that inflammation is a prerequisite for pulp healing, with series of events ahead of regeneration. Immunocompetent cells are recruited in the apical part. They slide along the root and migrate toward the crown. Due to the high alkalinity of the capping agent, pulp cells display mild inflammation, proliferate, and increase in number and size and initiate mineralization. Pulp fibroblasts become odontoblast-like cells producing type I collagen, alkaline phosphatase, and SPARC/osteonectin. Molecules of the SIBLING family, matrix metalloproteinases, and vascular and nerve mediators are also implicated in the formation of a reparative dentinal bridge, osteo/orthodentin closing the pulp exposure. Beneath a calciotraumatic line, a thin layer identified as reactionary dentin underlines the periphery of the pulp chamber. Inflammatory and/or noninflammatory processes contribute to produce a reparative dentinal bridge closing the pulp exposure, with minute canaliculi and large tunnel defects. Depending on the form and severity of the inflammatory and noninflammatory processes, and according to the capping agent, pulp reactions are induced specifically. PMID:26538825

  1. Ethanol/Water Pulps From Sugar Cane Straw and Their Biobleaching With Xylanase from Bacillus pumilus

    NASA Astrophysics Data System (ADS)

    Moriya, Regina Y.; Gonçalves, Adilson R.; Duarte, Marta C. T.

    The influence of independent variables (temperature and time) on the cooking of sugar cane straw with ethanol/water mixtures was studied to determine operating conditions that obtain pulp with high cellulose contents and a low lignin content. An experimental 22 design was applied for temperatures of 185 and 215°C, and time of 1 and 2.5 h with the ethanol/water mixture concentration and constant straw-to-solvent ratio. The system was scaled-up at 200°C cooking temperature for 2 h with 50% ethanol-water concentration, and 1∶10 (w/v) straw-to-solvent ratio to obtain a pulp with 3.14 cP viscosity, 58.09 kappa-number, and the chemical composition of the pulps were 3.2% pentosan and 31.5% lignin. Xylanase from Bacillus pumilus was then applied at a loading of 5-150 IU/g dry pulp in the sugar cane straw ethanol/water pulp at 50°C for 2 and 20 h. To ethanol/water pulps, the best enzyme dosage was found to be 20 IU/g dry pulp at 20 h, and a high enzyme dosage of 150 IU/g dry pulp did not decrease the kappa-number of the pulp.

  2. Papermaking properties of aspen ultrahigh-yield mechanical pulps

    Treesearch

    J. N. McGovern; T. H. Wegner

    1991-01-01

    Eleven types of aspen ultra-high-yield (90% and above) mechanical pubs were evaluated for their chemical compositions (including sulfur), handsheet strength, and optical properties, fiber length indices, and fiberizing energies. The pulping processes were stone groundwood, pressurized stone groundwood, refiner mechanical, thermomechanical, chemimechanical (alkaline...

  3. Enzymatic removal of free and conjugated sterols forming pitch deposits in environmentally sound bleaching of eucalypt paper pulp.

    PubMed

    Gutiérrez, Ana; Del Rio, José C; Ibarra, David; Rencoret, Jorge; Romero, Javier; Speranza, Mariela; Camarero, Susana; Martínez, María Jesus; Martínez, Angel T

    2006-05-15

    Free and conjugated sterols are among the main compounds responsible for pitch deposition in the manufacture of wood chemical pulps, making difficult the implementation of totally chlorine free bleaching (TCF) and closure of bleach plant circuits. In this work, the suitability of oxidative enzymes in efficiently removing sterols from eucalypt pulps is revealed. The enzymatic treatment was applied as an additional stage of an industrial-type TCF sequence for bleaching eucalypt kraft pulp. The pulp obtained after oxygen delignification was treated with a high-redox potential and thermostable fungal laccase using 1-hydroxybenzotriazole as an enzyme mediator. This pulp was further submitted to chelation and peroxide stages and compared with a control TCF pulp obtained using chemical reagents. The composition of the lipophilic extractives in the pulps and the corresponding liquids after the different stages was analyzed by gas chromatography and gas chromatography--mass spectrometry. Free sitosterol and sitosterol esters and glucosides, the major lipophilic compounds in eucalypt pulps, were completely removed during the laccase-mediator treatment. Only some intermediate products from sitosterol oxidation remained after the laccase stage, as well as in the final pulp. Pulp brightness was also improved due to the simultaneous removal of lignin by the laccase-mediator treatment.

  4. Water requirements of the pulp and paper industry

    USGS Publications Warehouse

    Mussey, Orville D.

    1955-01-01

    Water, of varied qualities, is used for several purposes in the manufacture of pulp and paper, as a vehicle for transporting the constituents of paper in the paper machines; as process water for cooking wood chips to make pulp; as a medium for heat transfer; and for washing the pulpwood, the woodpulp, and the machines that handle the pulp. About 3,200 million gallons of water was withdrawn from surface- and ground-water sources each day during 1950 for the use of the pulp and paper industry. This is about 4 percent of the total estimated industrial withdrawal of water in the Nation The paper industry in the United States has been growing at a rapid rate. It has increased about tenfold in the last 50 years and has doubled every 15 years. The 1950 production of paper was about 24 million tons, which amounts to about 85 percent of the domestic consumption. In 1950, the pulp mills of the country produced more than 14 million tons of woodpulp, which supplied about 85 percent of the demand by the paper mills and other industries. The remainder of the fiber for paper manufacture was obtained from imported woodpulp, from reclaimed wastepaper, and from other fibers including rags and straw. The nationwide paper consumption for 1955 has been estimated at 31,700,000 tons. Woodpulp is classified according to the process by which it is made. Every woodpulp has characteristics that are carried over into the many and diverse grades of paper. Groundwood pulp is manufactured by simply grinding up wood and refining the resulting product. Soda, sulfite, and sulfate pulps are manufactured by chemically breaking down the lignin that cements the cellulose of the wood together and removing, cleaning, and sometimes bleaching the resulting fibers. Some woodpulp is produced by other methods. Sulfate-pulp mills are increasing in number and in rated daily capacity and are manufacturing more than half of the present domestic production of woodpulp. Most of the newer and larger woodpulp mills

  5. Method of treating contaminated HEPA filter media in pulp process

    DOEpatents

    Hu, Jian S.; Argyle, Mark D.; Demmer, Ricky L.; Mondok, Emilio P.

    2003-07-29

    A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

  6. Fluoropolymer use in the pulp and paper industry

    SciTech Connect

    Magdzinski, L.

    1999-11-01

    Fluoropolymers are ubiquitous in the pulp and paper industry. Fluoropolymer-lined pumps, valves, pipes, tanks, scrubbers, and towers are encountered frequently in the pulp mill. Chemically resistant fluoropolymer filter fabrics are used in bleach plant washers and flue gas scrubbers. In the recovery cycle, fluoropolymer coatings and fluoroelastomers are used as gaskets and expansion joints in accumulators and heat exchangers. Fluoropolymer-containing paper machine fabrics, roll covers, and greases provide corrosion-free, clean and smooth performance. The array of fluorinated materials for different applications is detailed. New corrosion and caustic resistant filter fabrics, surfacing veils, paints and ductwork are presented.

  7. Electron treatment of wood pulp for the viscose process

    NASA Astrophysics Data System (ADS)

    Stepanik, T. M.; Ewing, D. E.; Whitehouse, R.

    2000-03-01

    Electron processing is currently being evaluated by several viscose producers for integration into their process. The viscose industry converts dissolving wood pulp into products such as staple fibre, filament, cord, film, packaging, and non-edible sausage casings. These materials are used in the clothing, drapery, hygiene, automobile, food, and packaging industries. Viscose producers are facing increasingly high production costs and stringent environmental regulations that have forced some plants to close. Electron treatment of wood pulp can significantly reduce the amounts of chemicals used for producing viscose and the production of hazardous pollutants. Acsion Industries has worked with companies worldwide to demonstrate the benefits of using electron treated pulp for producing viscose (rayon). This paper describes the viscose process, the benefits of using electron treatment in the viscose process, and Acsion's efforts in developing this technology.

  8. Wastewater treatment of pulp and paper industry: a review.

    PubMed

    Kansal, Ankur; Siddiqui, Nihalanwar; Gautam, Ashutosh

    2011-04-01

    Pulp and paper industries generate varieties of complex organic and inorganic pollutants depending upon the type of the pulping process. A state-of-art of treatment processes and efficiencies of various wastewater treatment is presented and critically reviewed in this paper. Process description, source of wastewater and their treatment is discussed in detail. Main emphasis is given to aerobic and anaerobic wastewater treatment. In pulp and paper mill wastewater treatment aerobic treatment includes activated sludge process, aerated lagoons and aerobic biological reactors. UASB, fluidized bed, anaerobic lagoon and anaerobic contact reactors are the main technologies for anaerobic wastewater treatment. It is found that the combination of anaerobic and aerobic treatment processes is much efficient in the removal of soluble biodegradable organic pollutants. Color can be removed effectively by fungal treatment, coagulation, chemical oxidation, and ozonation. Chlorinated phenolic compounds and adsorable organic halides (AOX) can be efficiently reduced by adsorption, ozonation and membrane filtration techniques.

  9. Fixed prosthodontics: avoiding pulp death.

    PubMed

    1995-11-01

    Fixed prostheses & crowns have become a major part of dental services due to aging population & increase in retention of natural teeth. In some practices, alarming numbers of endodontic procedures are necessary because of pulp damage after prosthesis cementation. Third party payment companies show many teeth receiving crowns require endodontic therapy within 5 years. Following report describes: (1) 14 potential causes of endodontic need related to fixed prosthodontics; & (2) state-of-art concepts to prevent pulp damage.

  10. Composition, texture and methane potential of cellulosic residues from Lewis acids organosolv pulping of wheat straw.

    PubMed

    Constant, Sandra; Barakat, Abdellatif; Robitzer, Mike; Di Renzo, Francesco; Dumas, Claire; Quignard, Françoise

    2016-09-01

    Cellulosic pulps have been successfully isolated from wheat straw through a Lewis acids organosolv treatment. The use of Lewis acids with different hardness produced pulps with different delignification degrees. The cellulosic residue was characterised by chemical composition, X-ray diffraction, FT-IR spectroscopy, N2 physisorption, scanning electron microscopy and potential for anaerobic digestibility. Surface area and pore volume increased with the hardness of the Lewis acid, in correspondence with the decrease of the amount of lignin and hemicellulose in the pulp. The non linearity of the correlation between porosity and composition suggests that an agglomeration of cellulose fibrils occurs in the early stages of pulping. All organosolv pulps presented a significantly higher methane potential than the parent straw. A methane evolution of 295Ncm(3)/g OM was reached by a moderate improvement of the accessibility of the native straw. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The Fractionation of Loblolly Pine Woodchips Into Pulp For Making Paper Products

    SciTech Connect

    Kiran Kadam, PhD

    2006-11-30

    The overall goal of the project was to test the PureVision biomass fractionation technology for making pulp from loblolly pine. A specific goal was to produce a pulp product that is comparable to pulp produced from the kraft process, while reducing the environmental effects of the kraft process, known to be a highly pollutant process. The overall goal of the project was met by using the biomass fractionation concept for making pulp product. This proof-of-concept study, done with Southern pine pinchips as feedstock, evaluated NaOH concentration and residence time as variables in single-stage cocurrent pulping process. It can be concluded that 1% NaOH is adequate for effective delignification using the PureVision process; this is about 1/3 of that used in the kraft process. Also, the PureVision process does not use sulfur-based chemicals such as N2S and hence, is environmentally more benign.

  12. Isolation and characterization of structural components of Aloe vera L. leaf pulp.

    PubMed

    Ni, Y; Turner, D; Yates, K M; Tizard, I

    2004-12-20

    The clear pulp, also known as inner gel, of Aloe vera L. leaf is widely used in various medical, cosmetic and nutraceutical applications. Many beneficial effects of this plant have been attributed to the polysaccharides present in the pulp. However, discrepancies exist regarding the composition of pulp polysaccharide species and an understanding of pulp structure in relation to its chemical composition has been lacking. Thus, we examined pulp structure, isolated structural components and determined their carbohydrate compositions along with analyzing a partially purified pulp-based product (Acemannan hydrogel) used to make Carrisyn hydrogel wound dressing. Light and electron microscopy showed that the pulp consisted of large clear mesophyll cells with a diameter as large as 1000 microm. These cells were composed of cell walls and cell membranes along with a very limited number of degenerated cellular organelles. No intact cellular organelles were found in mesophyll cells. Following disruption of pulp by homogenization, three components were isolated by sequential centrifugation. They were thin clear sheets, microparticles and a viscous liquid gel, which corresponded to cell wall, degenerated cellular organelles and liquid content of mesophyll cells based on morphological and chemical analysis. These three components accounted for 16.2% (+/-3.8), 0.70% (+/-0) and 83.1% of the pulp on a dry weight basis. The carbohydrate composition of each component was distinct; liquid gel contained mannan, microparticles contained galactose-rich polysaccharide(s) and cell walls contained an unusually high level of galacturonic acid (34%, w/w; Gal A). The same three components were also found in Acemannan Hydrogel with mannan as the predominant component. Thus, different pulp structural components are associated with different polysaccharides and thus may potentially be different functionally. These findings may help lay a basis for further studies and development of better

  13. Soda-anthraquinone pulping of palm oil empty fruit bunches and beating of the resulting pulp.

    PubMed

    Jiménez, L; Serrano, L; Rodríguez, A; Sánchez, R

    2009-02-01

    The influence of soda-anthraquinone pulping variables (temperature, time and soda concentration) and beating (number of PFI beating revolution) of palm oil empty fruit bunches (EFB) on the resulting paper sheets was studied, with a view to identifying the optimum operating conditions. Equations were derived that reproduced the properties of the paper sheets with errors less than 10-12% in 90-95% of cases. An optimum compromise was found as regards operating conditions (15% soda, 170 degrees C, 70 min and 2400 number of PFI beating revolutions) that provided paper properties departing by less than 12% from their optimum values (59.63 Nm/g tensile index, 4.48% stretch, 4.17 kN/g burst index and 7.20 m Nm(2)/g tear index), and a beating grade of 47.5 degrees SR, acceptable to obtain paper sheets. Because these conditions involve a lower soda, temperature, time and beating than those required to maximize the studied paper properties, they can save chemical reagents, energy and immobilized capital for industrial facilities. On the other hand, the stretch properties of these pulp beaten are higher than those of others non-wood pulps, as wheat straw and olive wood.

  14. Bio-refinery system of DME or CH4 production from black liquor gasification in pulp mills.

    PubMed

    Naqvi, M; Yan, J; Fröling, M

    2010-02-01

    There is great interest in developing black liquor gasification technology over recent years for efficient recovery of bio-based residues in chemical pulp mills. Two potential technologies of producing dimethyl ether (DME) and methane (CH(4)) as alternative fuels from black liquor gasification integrated with the pulp mill have been studied and compared in this paper. System performance is evaluated based on: (i) comparison with the reference pulp mill, (ii) fuel to product efficiency (FTPE) and (iii) biofuel production potential (BPP). The comparison with the reference mill shows that black liquor to biofuel route will add a highly significant new revenue stream to the pulp industry. The results indicate a large potential of DME and CH(4) production globally in terms of black liquor availability. BPP and FTPE of CH(4) production is higher than DME due to more optimized integration with the pulping process and elimination of evaporation unit in the pulp mill.

  15. On hexenuronic acid (HexA) removal and mediator coupling to pulp fiber in the laccase/mediator treatment.

    PubMed

    Cadena, Edith M; Du, Xueyu; Gellerstedt, Göran; Li, Jiebing; Fillat, Amanda; García-Ubasart, Jordi; Vidal, Teresa; Colom, Josep F

    2011-02-01

    Flax soda/AQ pulps were treated with different fungal laccase-mediator combinations followed by physical and chemical characterization of the pulps to obtain a thorough understanding of the laccase/mediator effects on hexenuronic acid (HexA) removal and the coupling of mediator onto pulps for fiber functionalization. Large differences were found and the presence of lauryl gallate (LG) during Trametes villosa laccase (TvL) treatment (TvL+LG) resulted in a much larger reduction of pulp-linked HexA than the combination of p-coumaric acid (PCA) and Pycnoporus cinnabarinus laccase (PcL). A major portion of LG became attached to the pulp as revealed by an increase in the kappa number and further confirmed by thioacidolysis and (1)H NMR analysis of solubilized pulp fractions. Additional experiments with other chemical pulps and isolated pulp xylan and lignin revealed that HexA seems to be the sole pulp component attacked by TvL+LG. As a substrate for TvL, the reaction preference order is PCA>HexA>LG.

  16. Impact of hemicellulose pre-extraction for bioconversion on birch Kraft pulp properties.

    PubMed

    Helmerius, Jonas; von Walter, Jonas Vinblad; Rova, Ulrika; Berglund, Kris A; Hodge, David B

    2010-08-01

    The combination of hemicellulose extraction with chemical pulping processes is one approach to generate a sugar feedstock amenable to biochemical transformation to fuels and chemicals. Extractions of hemicellulose from silver birch (Betula pendula) wood chips using either water or Kraft white liquor (NaOH, Na(2)S, and Na(2)CO(3)) were performed under conditions compatible with Kraft pulping, using times ranging between 20 and 90 min, temperatures of 130-160 degrees C, and effective alkali (EA) charges of 0-7%. The chips from select extractions were subjected to subsequent Kraft pulping and the refined pulps were made into handsheets. Several metrics for handsheet strength properties were compared with a reference pulp made without an extraction step. This study demonstrated that white liquor can be utilized to extract xylan from birch wood chips prior to Kraft cooking without decreasing the pulp yield and paper strength properties, while simultaneously impregnating cooking alkali into the wood chips. However, for the alkaline conditions tested extractions above pH 10 resulted in low concentrations of xylan. Water extractions resulted in the highest final concentrations of xylan; yielding a liquor without the presence of toxic or inhibitory inorganics and minimal soluble aromatics that we demonstrate can be successfully enzymatically hydrolyzed to monomeric xylose and fermented to succinic acid. However, water extractions were found to negatively impact some pulp properties including decreases in compression strength, bursting strength, tensile strength, and tensile stiffness while exhibiting minimal impact on elongation and slight improvement in tearing strength index.

  17. Dissolving pulp from jute stick.

    PubMed

    Matin, Mhafuza; Rahaman, M Mostafizur; Nayeem, Jannatun; Sarkar, Mamon; Jahan, M Sarwar

    2015-01-22

    Jute stick is woody portion of jute plant, which remain as leftover after extracting bast fibre. Presently, it is being used for fencing in the rural area. In this investigation, biorefinery concept was initiated in producing dissolving pulp from jute stick by pre-hydrolysis kraft process. At 170°C for 1h of pre-hydrolysis, 70% of hemicelluloses was dissolved with negligible loss of α-cellulose. At this condition, 75% of dissolved sugars in the pre-hydrolysis liquor were in the oligomeric form. The pre-hydrolysed jute stick was subsequently pulped by kraft process with the variation of active alkali. The pulp yield was 36.2% with kappa number 18.5 at the conditions of 16% active alkali for 2h of cooking at 170°C. Final pulp was produced with 92% α-cellulose and 89% brightness after D0EpD1EpD1 bleaching. The produced dissolving pulp can be used in rayon production.

  18. Electric pulp testing: a review.

    PubMed

    Lin, J; Chandler, N P

    2008-05-01

    Electric pulp testing (EPT) has been available for more than a century and used in dental practices worldwide. This article provides an overview of this diagnostic aid. The PubMed database from 1953 was used initially; the reference list for pulp testing featured 1071 articles, and for EPT identified 121 papers. A forward search was undertaken on these articles and using selected author names. Potentially relevant material was also sought in contemporary endodontic texts, while older textbooks on endodontics, operative dentistry and pain revealed historic information and primary research not found electronically. A short account of the innervation of the pulp is followed by an historic overview. Clinical considerations discussed include tooth isolation, glove wearing and tester electrode placement. Orthodontic treatment, pacemaker wearing and patient medications are considered. Research applications are also discussed. While EPT is valuable, no single pulp testing technique can reliably diagnose all pulp conditions. Careful collection of patient history regarding the problem tooth and prudent use of appropriate radiographs are also helpful. The shortcomings of electric tests, especially in the case of immature and concussed teeth, must be understood. The demeanour of the patient and the responses given by control teeth also require careful consideration.

  19. Role of human pulp fibroblasts in angiogenesis.

    PubMed

    Tran-Hung, L; Mathieu, S; About, I

    2006-09-01

    After pulp amputation, complete pulp healing requires not only reparative dentin production but also fibroblast proliferation, nerve fiber growth, and neoangiogenesis. This study was designed to investigate the role of pulp fibroblasts in angiogenesis. Human pulp fibroblasts from third molars co-cultured with human umbilical vein endothelial cells induced the organization of endothelial cells and the formation of tubular structures corresponding to capillaries in vivo. The direct contact between both cells was not necessary to induce angiogenesis, and the observed effect was due to soluble factors. This was confirmed with neutralizing antibodies against FGF-2 and VEGF, which decreased the angiogenic effects of these soluble factors. Immunohistochemistry showed that both FGF-2 and VEGF were expressed in human dental pulp fibroblasts, and this expression increased after injury. These results suggest that the pulp fibroblasts secrete angiogenic factors, which are necessary for complete pulp healing, particularly at the pulp injury site.

  20. Scale deposits in kraft pulp bleach plants with reduced water consumption: a review.

    PubMed

    Huber, Patrick; Burnet, Auphélia; Petit-Conil, Michel

    2014-08-01

    The general tendency in the pulp industry towards reduced fresh water consumption and minimum effluent causes major deposit problems in mills. Chemical pulp bleach plants are affected by several types of mineral deposits, the most frequent being calcite, barite and calcium oxalate. In this review, the phenomena leading to scaling in chemical pulp bleaching are discussed, together with strategies for limiting deposits. The merits of various chemical methods in estimating scaling risks are compared. Chemical speciation methods are used throughout this review to gain a better understanding and prediction of scaling phenomena. Coupled chemical process simulations are anticipated to be a crucial way of solving deposition problems in bleach plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Research in bagasse pulp bleaching

    SciTech Connect

    Fernandez, N.; Naranjo, M.E.; Alvarez, J.; Sardinas, O.; Serrantes, M.

    1982-01-01

    Bleaching of soda and sulfate bagasse pulps by CED, CEH, CEHD, and O/alkali CED sequences gave products with Elrepho brightness 85-90, Post color no. 1.3-2.5, viscosity 20-28 cP, tear factor 60-78, and breaking length 3710-4590 m. Bleaching bagasse pulp with Na/sub 2/S/sub 2/O/sub 4/-NaClO increased its brightness increasing temperature, pH, and NaOCl consumption. Brightening of mechanical bagasse pulp with H/sub 2/O/sub 2/, Na/sub 2/S/sub 2/O/sub 4/, and NaClO reduced the consumption of peroxide, Na/sub 2/S/sub 2/O/sub 4/, and NaOCl by 0.5-0.8, 0.5-1.5, and 10-12%, respectively.

  2. Biomechanical pulping : a mill-scale evaluation

    Treesearch

    Masood. Akhtar; Gary M. Scott; Ross E. Swaney; Mike J. Lentz; Eric G. Horn; Marguerite S. Sykes; Gary C. Myers

    1999-01-01

    Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory...

  3. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1720 Pulp tester. (a) Identification. A pulp tester is an AC or...

  4. Kraft pulping of industrial wood waste

    Treesearch

    Aziz. Ahmed; Masood. Akhtar; Gary C. Myers; Gary M. Scott

    1998-01-01

    Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine...

  5. Methanol-reinforced kraft pulping

    SciTech Connect

    Norman, E.; Olm, L.; Teder, A. )

    1993-03-01

    The addition of methanol to a high-sulfidity kraft cook on Scandinavian softwood chips was studied under different process conditions. Delignification and the degradation of carbohydrates were accelerated, but the effect on delignification was greater. Thus, methanol addition improved selectivity. The positive effect of methanol could also be observed for modified kraft cooks having a leveled out alkali concentration and lower concentration of sodium ions and dissolved lignin at the end of the cook. Methanol addition had no discernible effect on pulp strength or on pulp bleachability.

  6. Deinked pulp manufacturers make a midwest market

    SciTech Connect

    White, K.M. ); Meade, K.

    1993-09-01

    Deinked pulp manufacturers, a burgeoning trend in recycling, are opening up the market for office waste paper in the Midwest. Great Lakes Pulp and Fibre, Inc., (Menominee, Michigan), a new paper group formed by industry veterans, is planning a major deinked pulp mill in Michigan's Upper Peninsula that will recycle large amounts of office waste paper. The mill will have the capacity to process nearly 275,000 tons per year (tpy)-673 tpd-of mixed office paper into 182,000 tpd of sheet-dried, deinked pulp. That pulp would be sold to nearby fine paper manufacturers that want to have recycled content without adding their own deinking.

  7. Glutaraldehyde: an alternative to formocresol for vital pulp therapy.

    PubMed

    Davis, M J; Myers, R; Switkes, M D

    1982-01-01

    Based on the limited results of this eight-week comparison of formocresol and glutaraldehyde, it would appear that glutaraldehyde may offer distinct advantages over formocresol, in the treatment of cariously exposed primary and young permanent teeth. In particular, due to its chemical structure, it is more active in fixing the surface tissues and is more rapidly limited in its depth of penetration through these tissues. Glutaraldehyde does not exhibit as significant an ability to induce the total loss of vitality, in the radicular pulp tissues. The progression of formocresol treated pulps to apparent fibrotic replacement via granulation-tissue ingrowth, through the apex, does not occur with the glutaraldehyde-treated pulp tissues. There may, however, be a slow progression of fibrotic replacement of the glutaraldehyde fixed tissue, in the coronal portion of the radicular pulp. Perhaps most importantly it would seem that since the glutaraldehyde does not perfuse the tissues to the apex, it will not demonstrate systemic distribution and other extradental phenomena, as have been identified with the use of formocresol

  8. Pulp size in molars: underestimation on radiographs.

    PubMed

    Chandler, N P; Ford, T R Pitt; Monteith, B D

    2004-08-01

    The aim was to determine whether radiographs provide a clinically useful indication of pulp size in diseased/restored human first molar teeth, and to investigate accessibility of pulp tissue for diagnostic testing using laser Doppler flowmetry (LDF). Extracted teeth of known age were collected. Restorative materials were removed and teeth with evidence of pulp exposures excluded. Fifty-six teeth were radiographed from buccal and mesial aspects, and then their crowns were sectioned axiobuccolingually and photographed. Images were digitally scanned and measurements made of the total pulp area (above a line across the most superior part of the pulpal floor) and the pulp area in the clinical crown (superior to a line between the amelocemental junctions). The pulp width at the cervix and the highest point of the pulp were also recorded. Data were analysed using Pearson correlations. Pulp areas within the clinical crowns were significantly larger than indicated by radiographs, by 23% in the case of the clinically attainable buccal view (P < 0.05). Pulps may be more accessible to flowmeter testing than they appear. Absence of pulp tissues in the crown was recorded in equal numbers of teeth on radiographs and sections, but with agreement for only one tooth. Sixteen per cent of the teeth had no pulp area in the clinical crown when sectioned, but might still be suitable for testing using LDF.

  9. Laccase for biobleaching of eucalypt kraft pulp by means of a modified industrial bleaching sequence.

    PubMed

    Moldes, D; Vidal, T

    2012-01-01

    Biobleaching of kraft pulp is a possible application of laccase, but it has not been described in detail for complete industrial bleaching sequences yet. Therefore, in this work, the biobleaching of Eucalyptus globulus kraft pulp was performed using a modified industrial totally chlorine-free sequence. The modification consisted in the substitution of an enzymatic delignification stage, based on the application of laccase from Trametes villosa, for the first alkaline extraction one. The enzymatic stage was performed with several synthetic and natural mediators, namely 1-hydroxybenzotriazole (HBT), violuric acid (VA), methyl syringate, and syringaldehyde. Several pulp properties were analyzed after each stage of the bleaching process--kappa number, ISO brightness, viscosity, and optical properties of CIEL*a*b* system. The new biobleaching sequence improved the pulp properties, in comparison to the conventional bleaching sequence, if HBT or VA was used as mediators. VA was selected as the best mediator of those tested and the effect of its concentration in the enzymatic stage was subsequently studied. Reducing the initial concentration by 30%, the same pulp quality was obtained, but if the reduction attained 60%, an important decrease in pulp integrity was detected. The modified bleaching sequence could improve the bleached pulp properties (kappa number 10%, ISO brightness 1%, and viscosity 5%) in comparison to the mill sequence. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  10. Automatic stimulus breaker for electric dental pulp tester using pain response.

    PubMed

    Nam, K C; Lee, S J; Song, C G; Kim, D W

    2005-05-01

    The pulp test provides a means of examining the vitality of dental pulp using physical or chemical stimulation. During electrical pulp testing, an electrical current stimulates the intradental nerve, which may be painful and stressful to patients. The study involved measurement of the electromyogram (EMG) from the anterior belly of the digastric muscle, finger movement and voice response during electrical pulp testing. The excessive stimulus time from the onset time of response (EMG, voice and finger movement) to the end of the stimulation was obtained. The results indicated that the responses occurred in the order: EMG, finger and voice. Based on these results, an automatic stimulus shut-off circuit was developed using the above-mentioned responses to stimulus during electric pulp testing. Excessive stimulus time was reduced by prompt switching-off of the pulp tester output, 64 ms on average after the first detected response (EMG). Consequently, excessive stimulus times were reduced by 284 and 152 ms on average for the subject and examiner disconnection, respectively, using the developed automatic shut-off circuit. Therefore it was possible to minimise pain and stress by reducing excessive pulp stimulation.

  11. Biological modification of loblolly pine chips with Ceriporiopsis subvermispora prior to kraft pulping

    NASA Astrophysics Data System (ADS)

    Villalba, Laura L.

    The ability of the white-rot fungus Ceriporiopsis subvermispora to selectively degrade lignin in loblolly pine chips and the effect on kraft pulps was investigated. The effect of fungal treatment was assessed by comparing changes in untreated wood chips with chips incubated for two and four weeks. The kraft pulping step included two different cooking times and two levels of chemical dosage as the variables, 16 and 22% for the effective alkali and 60 and 90 min at 170°C. The other cooking variables were kept constant for all the experiments and were: sulfidity, 22%; liquor/wood ratio 4:1; time to Tmax 90 min.; Tmax 170°C. Scanning electron microscopy (SEM) revealed that the colonization introduced significant chemical and physical changes. Pore size distribution analyses revealed a statistically significant increase in the average pore size as fungal treatment progressed. Significant reduction in the extractives content (23%) was found in the first 2 weeks, after which the reduction leveled off. Lignin losses reached 2% in the first 2 weeks of incubation, followed by an 11% loss after 4 weeks of treatment. Lignin phenolic hydroxyl groups increased 14% after 4 weeks of incubation. Fungal treatment caused 4 and 6% carbohydrate loss in 2 and 4 weeks-treated chips, respectively. The selectivity of the fungal treatment was emphasized in the subsequent kraft pulping. The best response regarding improved delignification was found in kraft pulps processed at the mildest pulping conditions without affecting pulp viscosity. Benefits of fungal treatment regarding freeness of kraft pulps were evidenced after 4 weeks of incubation with a maximum of 35% freeness reduction in kraft pulps refined at 12,000 rev in a PFI mill. Strength properties of kraft pulps of fungal treated chips were superior to those of the control. This method involves chemical and physical modification of wood chips using fungi. The approach improved chip impregnation, which in turn, led to more uniform

  12. Effect of organosolv and soda pulping processes on the metals content of non-woody pulps.

    PubMed

    González, M; Cantón, L; Rodríguez, A; Labidi, J

    2008-09-01

    In this work the effect of different pulping processes (ethyleneglycol, diethyleneglycol, ethanolamine and soda) of tow abounded raw materials (empty fruit bunches - EFB and rice straw) on the ash, silicates and metals (Fe, Zn, Cu, Pb, Mn, Ni and Cd) content of the obtained pulps have been studied. Results showed that pulps obtained by diethyleneglycol pulping process presented lower metals content (756 microg/g and 501 microg/g for EFB and rice straw pulp, respectively) than soda pulps (984 microg/g and 889 microg/g). Ethanolamine pulps presented values of holocellulose (74% and 77% for EFB and rice straw pulp, respectively), alpha-cellulose (74% and 69%), kappa number (18.7 and 18.5) and viscosity (612 and 90 6ml/g) similar to those of soda pulp, and lower lignin contents (11% and 12%).

  13. Biobleaching of wheat straw-rich soda pulp with alkalophilic laccase from gamma-proteobacterium JB: optimization of process parameters using response surface methodology.

    PubMed

    Singh, Gursharan; Ahuja, Naveen; Batish, Mona; Capalash, Neena; Sharma, Prince

    2008-11-01

    An alkalophilic laccase from gamma-proteobacterium JB was applied to wheat straw-rich soda pulp to check its bleaching potential by using response surface methodology based on central composite design. The design was employed by selecting laccase units, ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) concentration and pH as model factors. The results of second order factorial design experiments showed that all three independent variables had significant effect on brightness and kappa number of laccase-treated pulp. Optimum conditions for biobleaching of pulp with laccase preparation (specific activity, 65 nkat mg(-1) protein) were 20 nkat g(-1) of pulp, 2mM ABTS and pH 8.0 which enhanced brightness by 5.89% and reduced kappa number by 21.1% within 4h of incubation at 55 degrees C, without further alkaline extraction of pulp. Tear index (8%) and burst index (18%) also improved for laccase-treated pulp as compared to control raw pulp. Treatment of chemically (CEH1H2) bleached pulp with laccase showed significant effect on release of chromophores, hydrophobic and reducing compounds. Laccase-prebleaching of raw pulp reduced the use of hypochlorite by 10% to achieve brightness of resultant hand sheets similar to the fully chemically bleached pulp.

  14. 40 CFR 430.60 - Applicability; description of the semi-chemical subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Semi... of this subpart are applicable to discharges resulting from the integrated production of pulp and paper at semi-chemical mills. ...

  15. 40 CFR 430.60 - Applicability; description of the semi-chemical subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS THE PULP, PAPER, AND PAPERBOARD POINT SOURCE CATEGORY Semi... of this subpart are applicable to discharges resulting from the integrated production of pulp and paper at semi-chemical mills. ...

  16. Pulp Regeneration: Current Approaches and Future Challenges

    PubMed Central

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi

    2016-01-01

    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration. PMID:27014076

  17. Pulp Regeneration: Current Approaches and Future Challenges.

    PubMed

    Yang, Jingwen; Yuan, Guohua; Chen, Zhi

    2016-01-01

    Regenerative endodontics aims to replace inflamed/necrotic pulp tissues with regenerated pulp-like tissues to revitalize teeth and improve life quality. Pulp revascularization case reports, which showed successful clinical and radiographic outcomes, indicated the possible clinical application of pulp regeneration via cell homing strategy. From a clinical point of view, functional pulp-like tissues should be regenerated with the characterization of vascularization, re-innervation, and dentin deposition with a regulated rate similar to that of normal pulp. Efficient root canal disinfection and proper size of the apical foramen are the two requisite preconditions for pulp regeneration. Progress has been made on pulp regeneration via cell homing strategies. This review focused on the requisite preconditions and cell homing strategies for pulp regeneration. In addition to the traditionally used mechanical preparation and irrigation, antibiotics, irrigation assisted with EndoVac apical negative-pressure system, and ultrasonic and laser irradiation are now being used in root canal disinfection. In addition, pulp-like tissues could be formed with the apical foramen less than 1 mm, although more studies are needed to determine the appropriate size. Moreover, signaling molecules including stromal cell derived factor (SDF-1α), basic Fibroblast Growth Factor (bFGF), Platelet Derived Growth Factor (PDGF), stem cell factor (SCF), and Granulocyte Colony-Stimulating Factor (G-CSF) were used to achieve pulp-like tissue formation via a cell homing strategy. Studies on the cell sources of pulp regeneration might give some indications on the signaling molecular selection. The active recruitment of endogenous cells into root canals to regenerate pulp-like tissues is a novel concept that may offer an unprecedented opportunity for the near-term clinical translation of current biology-based therapies for dental pulp regeneration.

  18. Pulp reaction to vital bleaching.

    PubMed

    Fugaro, Jessica O; Nordahl, Inger; Fugaro, Orlando J; Matis, Bruce A; Mjör, Ivar A

    2004-01-01

    This study evaluated the histological changes in dental pulp after nightguard vital bleaching with 10% carbamide peroxide gel. Fifteen patients between 12 and 26 years of age with caries-free first premolars scheduled for orthodontic extraction were treated with 10% Opalescence (Ultradent Products, Inc). Tooth #5 had four days of bleaching, tooth #12 was treated for two weeks, tooth #21 was bleached for two weeks followed by two weeks without treatment and tooth #28, serving as the control, was without treatment. All teeth were extracted at the same time. Immediately after extraction, 4 mm of the most apical portion of the root was sectioned off and each specimen was placed in a vial containing 10% neutral buffered formalin. The samples were prepared for histological evaluation at the Scandinavian Institute of Dental Materials (NIOM) and microscopically examined independently at both NIOM and Indiana University School of Dentistry (IUSD). Pulp reactions were semi-quantitatively graded as none, slight, moderate and severe. Slight pulpal changes were detected in 16 of the 45 bleached teeth. Neither moderate nor severe reactions were observed. The findings indicate that the slight histological changes sometimes observed after bleaching tend to resolve within two weeks post-treatment. Statistical differences existed only between the untreated control and the four-day (p=0.0109) and two-week (p=0.0045) treatment groups. The findings from this study demonstrated that nightguard vital bleaching procedures using 10% carbamide peroxide might cause initial mild, localized pulp reactions. However, the minor histological changes observed did not affect the overall health of the pulp tissue and were reversible within two weeks post-treatment. Therefore, two weeks of treatment with 10% carbamide peroxide used for nightguard vital bleaching is considered safe for dental pulp.

  19. Signaling Molecules and Pulp Regeneration.

    PubMed

    Schmalz, Gottfried; Widbiller, Matthias; Galler, Kerstin M

    2017-09-01

    Signaling molecules play an essential role in tissue engineering because they regulate regenerative processes. Evidence exists from animal studies that single molecules such as members of the transforming growth factor beta superfamily and factors that induce the growth of blood vessels (vascular endothelial growth factor), nerves (brain-derived neurotrophic factor), or fibroblasts (fibroblast growth factor) may induce reparative dentin formation. Mainly the formation of atubular dentin (osteodentin) has been described after the application of single molecules or combinations of recombinant growth factors on healthy exposed pulps or in pulp regeneration. Generally, such preparations have not received regulatory approval on the market so far. Only the use of granulocyte colony-stimulating factors together with cell transplantation is presently tested clinically. Besides approaches with only 1 or few combined molecules, the exploitation of tissue-derived growth factors depicts a third promising way in dental pulp tissue engineering. Preparations such as platelet-rich plasma or platelet-rich fibrin provide a multitude of endogenous signaling molecules, and special regulatory approval for the market does not seem necessary. Furthermore, dentin is a perfect reservoir of signaling molecules that can be mobilized by treatment with demineralizing agents such as EDTA. This conditions the dentin surface and allows for contact differentiation of pulp stem cells into odontoblastlike cells, protects dentin from resorption, and enhances cell growth as well as attachment to dentin. By ultrasonic activation, signaling molecules can be further released from EDTA pretreated dentin into saline, thus avoiding cytotoxic EDTA in the final preparation. The use of dentin-derived growth factors offers a number of advantages because they are locally available and presumably are most fit to induce signaling processes in dental pulp. However, better characterization and standardization of the

  20. Process development for cigarette butts recycling into cellulose pulp.

    PubMed

    d'Heni Teixeira, Maria Betânia; Duarte, Marco Antônio B; Raposo Garcez, Loureine; Camargo Rubim, Joel; Hofmann Gatti, Thérèse; Suarez, Paulo Anselmo Ziani

    2017-02-01

    Cigarette butts, which are usually thrown on the ground or into ordinary bins, have been recognized as toxic residues since may contain cigarette contaminants and chemicals produced during combustion. Therefore, contaminants in cigarette butts can be leached by rain into surface water and thereby contaminate the environment. In Brazil, according to the National Policy on Solid Waste, all residues must be disposed of in an environmentally friendly manner. Although cigarette butts are not mentioned in the law, due to their characteristics, they may be classified as hazardous waste. At the University of Brasilia, a cellulose pulp production process from cigarette butts has been developed employing alkaline pulping. This process is presented as an alternative to environmentally friendly final disposal of this residue. During the process, a dark liquor is generated, which was found to contain lignin, carbonyls, metals, nicotine and specific tobacco nitrosamines. The dark liquor was treated by acidification to promote lignin precipitation, coagulation with chitosan and Al2(SO4)3 to remove metals and organic compounds and ozonized to oxidize resistant chemicals. The dark liquor presented a high chemical oxygen demand (COD; 29,986mg/L), which was partially removed by precipitation (20%), chitosan coagulation (66%) and ozonation (45.8%). As the remaining COD was still high, we proposed reusing the clarified effluent in alkaline pulping, which seemed to be the easiest and most efficient procedure with the lowest cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. New Approaches in Vital Pulp Therapy in Permanent Teeth

    PubMed Central

    Ghoddusi, Jamileh; Forghani, Maryam; Parisay, Iman

    2014-01-01

    Vitality of dental pulp is essential for long-term tooth survival. The aim of vital pulp therapy is to maintain healthy pulp tissue by eliminating bacteria from the dentin-pulp complex. There are several different treatment options for vital pulp therapy in extensively decayed or traumatized teeth. Pulp capping or pulpotomy procedures rely upon an accurate assessment of the pulp status, and careful management of the remaining pulp tissue. The purpose of this review is to provide an overview of new approaches in vital pulp therapy in permanent teeth. PMID:24396371

  2. Improved paper pulp from plants with suppressed cinnamoyl-CoA reductase or cinnamyl alcohol dehydrogenase.

    PubMed

    O'Connell, Ann; Holt, Karen; Piquemal, Joël; Grima-Pettenati, Jacqueline; Boudet, Alain; Pollet, Brigitte; Lapierre, Catherine; Petit-Conil, Michel; Schuch, Wolfgang; Halpin, Claire

    2002-10-01

    Transgenic plants severely suppressed in the activity of cinnamoyl-CoA reductase were produced by introduction of a partial sense CCR transgene into tobacco. Five transgenic lines with CCR activities ranging from 2 to 48% of wild-type values were selected for further study. Some lines showed a range of aberrant phenotypes including reduced growth, and all had changes to lignin structure making the polymer more susceptible to alkali extraction. The most severely CCR-suppressed line also had significantly decreased lignin content and an increased proportion of free phenolic groups in non-condensed lignin. These changes are likely to make the lignin easier to extract during chemical pulping. Direct Kraft pulping trials confirmed this. More lignin could be removed from the transgenic wood than from wild-type wood at the same alkali charge. A similar improvement in pulping efficiency was recently shown for poplar trees expressing an antisense cinnamyl alcohol dehydrogenase gene. Pulping experiments performed here on CAD-antisense tobacco plants produced near-identical results--the modified lignin was more easily removed during pulping without any adverse effects on the quality of the pulp or paper produced. These results suggest that pulping experiments performed in tobacco can be predictive of the results that will be obtained in trees such as poplar, extending the utility of the tobacco model. On the basis of our results on CCR manipulation in tobacco, we predict that CCR-suppressed trees may show pulping benefits. However, it is likely that CCR-suppression will not be the optimal target for genetic manipulation of pulping character due to the potential associated growth defects.

  3. Sequential (anaerobic/aerobic) biological treatment of Dalaman SEKA pulp and paper industry effluent.

    PubMed

    Tezel, U; Guven, E; Erguder, T H; Demirer, G N

    2001-01-01

    In the pulp and paper industry, lignin and other color compounds are removed by chemical agents in bleaching process. Use of chlorine-based agents results in production of degradation products which include various chloro-organic derivatives. Since these new compounds are highly chlorinated, they cause a problem in the treatment of pulp and paper industry wastewaters. Chemical precipitation, lagooning, activated sludge, and anaerobic treatment are the processes used for treating pulp and paper effluents. Furthermore, a combination of these processes is also applicable. In this study, the effluent of Dalaman SEKA Pulp and Paper Industry was examined for its toxic effects on anaerobic microorganisms by anaerobic toxicity assay. Additionally, this wastewater was applied to a sequential biotreatment process consisting of an upflow anaerobic sludge blanket as the anaerobic stage and a once-through completely mixed stirred tank as the aerobic stage. Results indicated that: (1) Dalaman SEKA Pulp and Paper Industry wastewater exerted no inhibitory effects on the anaerobic cultures under the studied conditions, and (2) application of a sequential biological (anaerobic/aerobic) system to treat the Dalaman SEKA Pulp and Paper Industry wastewater resulted in approximately 91% COD and 58% AOX removals at a HRT of 5 and 6.54 h for anaerobic and aerobic, respectively.

  4. Anaerobic treatment of pulp and paper mill effluents--status quo and new developments.

    PubMed

    Habets, Leo; Driessen, Willie

    2007-01-01

    Since the early 1980s, anaerobic treatment of industrial effluents has found widespread application in the pulp and paper industry. Over 200 installations are treating a large variety of different pulp and paper mill effluents. Amongst various anaerobic systems the UASB and IC are the most applied anaerobic reactor systems. Anaerobic treatment is well feasible for effluents originated from recycle paper mills, mechanical pulping (peroxide bleached), semi-chemical pulping and sulphite and kraft evaporator condensates. The advantages of anaerobic pre-treatment are (1) net production of renewable energy (biogas), (2) minimized bio-solids production, (3) minimal footprint and (4) reduced emission of greenhouse gases. Via in-line application of anaerobic treatment in closed circuits (paper kidney technology) further savings on cost of fresh water intake and effluent discharge levies are generated.

  5. Isolation and purification of feruloylated oligosaccharides from cell walls of sugar-beet pulp.

    PubMed

    Ralet, M C; Thibault, J F; Faulds, C B; Williamson, G

    1994-10-17

    Cell walls from sugar-beet pulp contain some feruloyl groups linked to the pectic neutral side-chains. Enzymic as well as chemical hydrolysis of the pulp yielded a series of feruloylated oligosaccharides, which have been purified by Sephadex LH-20 and Biogel P-2 chromatography in aqueous solvents. Feruloylated arabinose di-, tri-, hexa-, hepta-, and octa-saccharides as well as feruloylated galactose disaccharides were obtained after hydrolysis of the pulp with a mixture of fungal carbohydrases (Driselase). Feruloylated arabinose and galactose monosaccharides were obtained through mild acid hydrolyses. Both arabinose and galactose residues in the side-chains are feruloylated, 50-55% of the feruloyl groups being linked to arabinose residues and 45-50% to galactose residues. It is concluded that 1 out of 56 arabinose residues and 1 out of 16 galactose residues present as pectic side-chains in sugar-beet pulp carry a feruloyl group.

  6. Removal of COD and color loads in bleached kraft pulp effluents by bottom ashes from boilers.

    PubMed

    Van Tran, A

    2008-07-01

    The effectiveness of the bottom ashes from biomass and coal-fired boilers in removing chemical oxygen demand (COD) and colorloads in effluents of a kraft pulp bleachery plant is investigated. The effluents tested are those of the sulfuric acid treatment (A stage) of a hardwood kraft pulp, and of the first acidic (chlorine or chlorine dioxide) and second alkaline (extraction) stages in the chlorine and elemental chlorine-free (ECF) bleaching lines of hardwood and softwood kraft pulps. The coal-fired boiler's bottom ashes are unable to remove either COD or color load in the bleached kraft pulp effluents. However, the bottom ashes of the biomass boiler are effective in removing COD and color loads of the acidic and alkaline effluents irrespective of the bleaching process or wood species. In particular, these ashes increase the pH of all the effluents examined.

  7. Use of xylanase in the TCF bleaching of eucalyptus kraft pulp

    SciTech Connect

    Roncero, B.; Vidal, T.; Torres, A.L.; Colom, J.F.

    1996-10-01

    Environmental pressures are forcing the pulp and paper industry to develop new technologies that reduce or eliminate the presence of various contaminants in bleaching plant effluents. Oxygen delignification techniques, replacement of elemental chlorine with chlorine dioxide, ozone, hydrogen peroxide and new agents as well as the use of xylanase enzymes for biobleaching, reduce o eliminate the production of chlorinated organic substances. This paper compares the sequence XOZP with OZP in the bleaching of Eucalyptus globulus kraft pulps. It has been studied the influence of enzymatic treatment on the consumption of bleaching agents: ozone and hydrogen peroxide. Chemical, physical, optical and refining properties of pulps, as well as COD and colour of effluent are also studied. The xylanase treatment is positive and it is possible to manufacture fully bleached pulps at high brightness and viscosity without using chlorine compounds at a low ozone and hydrogen peroxide consumption.

  8. [Functional morphology of pulp tissue].

    PubMed

    Heine, H; Schaeg, G; Türk, R

    1989-01-01

    As compared with mesenchyme no genuine defense cells are developed in the tissue of the dental pulp and the nervous tissue. This is a further hint for the common development from ectoderm. The three dimensional meshwork of pulpa fibroblasts ("mesectoderm") is structured by elongated cell processes connected with each other by a variety of special cell junctions ("electronic cell coupling"). Metabolites from the microcirculation and neuropeptides from vegetative axons influence the activity of fibroblasts synthetizing groundsubstance. The meshwork of the groundsubstance has exclusion effects concerning molecules with a distinct molecular weight and charge. Thus a primitive defense system is established. With this the role of a newly described cell type of the dental pulp, the "lymphocytic pericyte" is discussed. Because of the poor capacity of the pulpa tissue for immunological reactions pathologically disorders may easily become chronically spreading their antigenic components throughout the body.

  9. [Confusion and solution for vital pulp therapy].

    PubMed

    Dingming, Huang; Qian, Lu; Qian, Liao; Ling, Ye; Xuedong, Zhou

    2017-06-01

    Dental pulp tissue plays a role in forming dentin, providing nutrition, conducting pain, and generating protective responses to environmental stimuli. Bacterial infection is the main cause of pulp disease, where histopathological changes are the histological basis for determining the choice of treatment and the evaluation of therapeutic effect. Thus, particular attention should be given to eliminate infection, as well as preserve and maintain pulpal health in teeth that show reversible or limited pulpal injuries. Vital pulp therapy, especially its indications and prognostic factors, has been a research hotspot that often causes confusion among clinicians. In this paper, we briefly introduce the confusion and solution for vital pulp therapy in terms of indications, pulp condition assessment, infection elimination, and capping material selection. In addition, we develop a clinical pathway and an operation normalization of vital pulp therapy to better perform the therapy.

  10. Chemical and functional characterization of seed, pulp and skin powder from chilto (Solanum betaceum), an Argentine native fruit. Phenolic fractions affect key enzymes involved in metabolic syndrome and oxidative stress.

    PubMed

    Orqueda, María Eugenia; Rivas, Marisa; Zampini, Iris Catiana; Alberto, María Rosa; Torres, Sebastian; Cuello, Soledad; Sayago, Jorge; Thomas-Valdes, Samanta; Jiménez-Aspee, Felipe; Schmeda-Hirschmann, Guillermo; Isla, María Inés

    2017-02-01

    The aim of this work was to assess the nutritional and functional components of powder obtained by lyophilization of whole fruits, seeds, pulp and skin from chilto (Solanum betaceum Cav) cultivated in the ecoregion of Yungas, Argentina. The powders have low carbohydrate and sodium content and are a source of vitamin C, carotenoid, phenolics, potassium and fiber. The HPLC-ESI-MS/MS analysis of the fractions enriched in phenolics allowed the identification of 12 caffeic acid derivatives and related phenolics, 10 rosmarinic acid derivatives and 7 flavonoids. The polyphenols enriched extracts before and after simulated gastroduodenal digestion inhibited enzymes associated with metabolic syndrome, including α-glucosidase, amylase and lipase and exhibited antioxidant activity by different mechanisms. None of the analyzed fruit powders showed acute toxicity or genotoxicity. The powders from the three parts of S. betaceum fruit may be a potential functional food and the polyphenol enriched extract of seed and skin may have nutraceutical properties.

  11. A biorefinery scheme to fractionate bamboo into high-grade dissolving pulp and ethanol.

    PubMed

    Yuan, Zhaoyang; Wen, Yangbing; Kapu, Nuwan Sella; Beatson, Rodger; Mark Martinez, D

    2017-01-01

    Bamboo is a highly abundant source of biomass which is underutilized despite having a chemical composition and fiber structure similar as wood. The main challenge for the industrial processing of bamboo is the high level of silica, which forms water-insoluble precipitates negetively affecting the process systems. A cost-competitive and eco-friendly scheme for the production of high-purity dissolving grade pulp from bamboo not only requires a process for silica removal, but also needs to fully utilize all of the materials dissolved in the process which includes lignin, and cellulosic and hemicellulosic sugars as well as the silica. Many investigations have been carried out to resolve the silica issue, but none of them has led to a commercial process. In this work, alkaline pretreatment of bamboo was conducted to extract silica prior to pulping process. The silica-free substrate was used to produce high-grade dissolving pulp. The dissolved silica, lignin, hemicellulosic sugars, and degraded cellulose in the spent liquors obtained from alkaline pretreatment and pulping process were recovered for providing high-value bio-based chemicals and fuel. An integrated process which combines dissolving pulp production with the recovery of excellent sustainable biofuel and biochemical feedstocks is presented in this work. Pretreatment at 95 °C with 12% NaOH charge for 150 min extracted all the silica and about 30% of the hemicellulose from bamboo. After kraft pulping, xylanase treatment and cold caustic extraction, pulp with hemicellulose content of about 3.5% was obtained. This pulp, after bleaching, provided a cellulose acetate grade dissolving pulp with α-cellulose content higher than 97% and hemicellulose content less than 2%. The amount of silica and lignin that could be recovered from the process corresponded to 95 and 77.86% of the two components in the original chips, respectively. Enzymatic hydrolysis and fermentation of the concentrated and detoxified sugar mixture

  12. Regulation of discharge of organochlorines from pulp mills in Canada

    NASA Astrophysics Data System (ADS)

    Hocking, Jennifer

    1991-03-01

    Organochlorines are a group of chemicals including dioxins and furans, at least some of which are highly toxic to humans. Organochlorines are formed as a byproduct of the chlorine bleaching process in pulp mills, as well as in other ways. Current federal and provincial environmental protection legislation in Canada is too general to adequately deal with the problem of organochlorine discharge. In Sweden and Germany strict new guidelines have been set for the discharge of organochlorines; strict guidelines are also planned for Alberta. The author recommends that new regulations, dealing specifically with organochlorine discharge, be promulgated under the new Canadian Environmental Protection Act. The new regulations should apply equally to all pulp mills. Strict enforcement, through cooperation of federal and provincial authorities, is also advised.

  13. Characterization and evaluation of golpata fronds as pulping raw materials.

    PubMed

    Jahan, M Sarwar; Chowdhury, D A Nasima; Islam, M Khalidul

    2006-02-01

    The chemical, morphological and anatomical studies of golpata fronds have been discussed. The lignin, pentosan and alpha-cellulose in golpata fronds were comparable to some common nonwood and hardwood raw materials. The alkali, water and dichloromethane solubility were higher than wood and common nonwood. The fiber length 1.73 mm was observed, which is little bit shorter than softwood and longer than hardwood but fiber diameter was very short. The pulpability of golpata fronds has also been studied. The pulp yield was very low and Kappa number was high. The strength properties were better than that of some common nonwood pulps. FT-IR spectrum and alkaline nitrobenzene oxidation products showed that golpata fronds lignin mainly consist of syringyl (S) and guaiacyl units (V).

  14. Laccase modification of the physical properties of bark and pulp of loblolly pine and spruce pulp

    Treesearch

    William Kenealy; John Klungness; Mandla Tshabalala; Eric Horn; Masood Akhtar; Roland Gleisner; Gisela Buschle-Diller

    2004-01-01

    Pine bark, pine pulp, and spruce pulp were reacted with laccase in the presence of phenolic laccase substrates to modify the fiber surface properties. The acid-base and dispersive characteristics of these modified steam-treated thermomechanical loblolly pine pulps were determined by inverse gas chromatography. Different combinations of substrates with laccase modified...

  15. Bioremediation of paper and pulp mill effluents.

    PubMed

    Murugesan, K

    2003-11-01

    Pulp and paper mill effluents pollute water, air and soil, causing a major threat to the environment. Several methods have been attempted by various researchers throughout the world for the removal of colour from pulp and paper mill effluents. The biological colour removal process uses several classes of microorganisms--bacteria, algae and fungi--to degrade the polymeric lignin derived chromophoric material. White rot fungi such as Phanerochaete chrysosporium, Corius versicolor, Trametes versicolor etc., are efficient in decolourizing paper and pulp mill effluents. Gliocladium virens, a saprophytic soil fungus decolourised paper and pulp mill effluents by 42% due to the production of hemicellulase, lignin peroxidase, manganese peroxidase and laccase.

  16. Diabetes induces metabolic alterations in dental pulp.

    PubMed

    Leite, Mariana Ferreira; Ganzerla, Emily; Marques, Márcia Martins; Nicolau, José

    2008-10-01

    Diabetes can interfere in tissue nutrition and can impair dental pulp metabolism. This disease causes oxidative stress in cells and tissues. However, little is known about the antioxidant system in the dental pulp of diabetics. Thus, it would be of importance to study this system in this tissue in order to verify possible alterations indicative of oxidative stress. The aim of this study was to evaluate some parameters of antioxidant system of the dental pulp of healthy (n = 8) and diabetic rats (n = 8). Diabetes was induced by streptozotocin in rats. Six weeks after diabetes induction, a pool of the dental pulp of the 4 incisors of each rat (healthy and diabetic) was used for the determination of total protein and sialic acid concentrations and catalase and peroxidase activities. Data were compared by a Student t test (p pulps from both groups presented similar total protein concentrations and peroxidase activity. Dental pulps of diabetic rats exhibited significantly lower free, conjugated, and total sialic acid concentrations than those of control tissues. Catalase activity in diabetic dental pulps was significantly enhanced in comparison with that of control pulps. The result of the present study is indicative of oxidative stress in the dental pulp caused by diabetes. The increase of catalase activity and the reduction of sialic acid could be resultant of reactive oxygen species production.

  17. Pulp and paper markets peaking amid slow economy, rising input costs, and erosion of profits : markets for paper, paperboard and woodpulp, 2007-2008

    Treesearch

    Peter J. Ince; Eduard L. Akim; Bernard Lombard; Tomas Parik

    2008-01-01

    In mid-2008, pulp and paper prices were at or near historic peak levels, but global demand conditions were weakening. Industry profits were eroded in 2007 and 2008 as sharply higher energy costs led to higher prices for fuel, freight, pulpwood, recovered paper, chemicals, and other inputs. Expanding pulp and paper capacity in China is having a huge impact on paper and...

  18. [Multiple pulp stones: report of a case and literature review].

    PubMed

    Feng, Xiao-jie; Luo, Xin; Li, Ren; Dong, Wei; Qi, Meng-chun

    2015-08-01

    Pulp stones were denaturation of pulp tissue, which were usually found in the pulp chamber. Generally, they were associated with caries and pulposis, and the occurrence of pulp stone increased with age. Pulp stones were frequently found by radiographic examination, and appeared as radiopaque lesions which were round or ovoid in shape. We reported an unusual case of multiple pulp stones with normal clinical crowns in a young female patient and analyzed the possible etiology.

  19. Modification in the properties of paper by using cellulase-free xylanase produced from alkalophilic Cellulosimicrobium cellulans CKMX1 in biobleaching of wheat straw pulp.

    PubMed

    Walia, Abhishek; Mehta, Preeti; Guleria, Shiwani; Shirkot, Chand Karan

    2015-09-01

    Alkalophilic Cellulosimicrobium cellulans CKMX1 isolated from mushroom compost is an actinomycete that produces industrially important and environmentally safer thermostable cellulase-free xylanase, which is used in the pulp and paper industry as an alternative to the use of toxic chlorinated compounds. Strain CKMX1 was previously characterized by metabolic fingerprinting, whole-cell fatty acids methyl ester analysis, and 16S rDNA and was found to be C. cellulans CKMX1. Crude enzyme (1027.65 U/g DBP) produced by C. cellulans CKMX1, having pH and temperature optima of 8.0 and 60 °C, respectively, in solid state fermentation of apple pomace, was used in the production of bleached wheat straw pulp. Pretreatment with xylanase at a dose of 5 U/g after pulping decreased pulp kappa points by 1.4 as compared with the control. Prebleaching with a xylanase dose of 5 U/g pulp reduced the chlorine charge by 12.5%, increased the final brightness points by approximately 1.42% ISO, and improved the pulp strength properties. Xylanase could be substituted for alkali extraction in C-Ep-D sequence and used for treating chemically bleached pulp, resulting in bleached pulp with higher strength properties. Modification of bleached pulp with 5 U of enzyme/g increased pulp whiteness and breaking length by 1.03% and 60 m, respectively; decreased tear factor of pulp by 7.29%; increased bulk weight by 3.99%, as compared with the original pulp. Reducing sugars and UV-absorbing lignin-derived compound values were considerably higher in xylanase-treated samples. Cellulosimicrobium cellulans CKMX1 has a potential application in the pulp and paper industries.

  20. Potential of thermo and alkali stable xylanases from Thielaviopsis basicola (MTCC-1467) in biobleaching of wood kraft pulp.

    PubMed

    Goluguri, Baby Rani; Thulluri, Chiranjeevi; Cherupally, Madhu; Nidadavolu, Nagaraju; Achuthananda, Das; Mangamuri, Lakshmi Narasu; Addepally, Uma

    2012-08-01

    Thermo- and alkali-stable xylanases produced from Thielaviopsis basicola (MTCC-1467) on low-cost carbon source like rice straw were evaluated for their potential application in biobleaching of wood kraft pulp. Enzyme treatment at retention time of 240 min with 20 IU/gm of dried pulp resulted in ~85.2 % of reduction in kappa number. When compared to control, 110.8, 93, and 72.2 % of enhancement in brightness (percent International Organization of Standardization), whiteness, and fluorescence, respectively, were observed for enzyme-treated pulp. Spectroscopic analysis showed significant release of chromophoric compounds from enzyme-treated pulp. Furthermore, scanning electron microscope studies of unbleached and enzyme bleached pulp revealed the effectiveness of enzymatic treatment. The enzyme-treated pulp subjected to later stages of chemical bleaching resulted in 16 % decrease in chlorine consumption along with considerable reduction in chemical oxygen demand percentage (14.5 %) level of effluent. Various pulp properties like fiber length, fiber width, burst strength, burst index, tear strength, tear index, tensile strength, and breaking length were also significantly improved after enzyme treatment when compared to control.

  1. Wood Pulp Digetster Wall Corrosion Investigation

    SciTech Connect

    Giles, GE

    2003-09-18

    The modeling of the flow in a wood pulp digester is but one component of the investigation of the corrosion of digesters. This report describes the development of a Near-Wall-Model (NWM) that is intended to couple with a CFD model that determines the flow, heat, and chemical species transport and reaction within the bulk flow of a digester. Lubrication theory approximations were chosen from which to develop a model that could determine the flow conditions within a thin layer near the vessel wall using information from the interior conditions provided by a CFD calculation of the complete digester. The other conditions will be determined by coupled solutions of the wood chip, heat, and chemical species transport and chemical reactions. The NWM was to couple with a digester performance code in an iterative fashion to provide more detailed information about the conditions within the NW region. Process Simulations, Ltd (PSL) is developing the digester performance code. This more detailed (and perhaps more accurate) information from the NWM was to provide an estimate of the conditions that could aggravate the corrosion at the wall. It is intended that this combined tool (NWM-PSL) could be used to understand conditions at/near the wall in order to develop methods to reduce the corrosion. However, development and testing of the NWM flow model took longer than anticipated and the other developments (energy and species transport, chemical reactions and linking with the PSL code) were not completed. The development and testing of the NWM are described in this report. In addition, the investigation of the potential effects of a clear layer (layer reduced in concentration of wood chips) near the wall is reported in Appendix D. The existence of a clear layer was found to enhance the flow near the wall.

  2. Multi stage peroxide and activated peroxide bleaching of kenaf bast pulp.

    PubMed

    Zeinaly, Farhad; Shakhes, Jalal; Zeinali, Nooshin

    2013-02-15

    Soda-anthraquinone kenaf bast pulp (12.5 kappa number and 32% ISO brightness) has been bleached with multi stage peroxide bleaching process. Bleaching process was carried out in different sequences of peroxide stage without and with activator (tetraacetylethylenediamine, TAED) to about 80% ISO brightness. Full bleached pulp production with high brightness and viscosity and also, low chemical oxygen demand (COD) and no adsorbable organic halogens (AOX) in effluent are the aims of this study. The effects of temperature, retention time, chemical charges, TAED/peroxide ratio and alkalinity have been studied in order to maximize the brightness gain at the lowest viscosity loss. H(2)O(2) was activated as bleaching agent under milder conditions, such as low alkalinity or low temperature, by TAED activator. Therefore, TAED charge caused to an improvement in viscosity, pulp yield and effluent COD load. Pre-treatment with EDTA for 30 min and in acidic condition gave 2-4% gain in ISO brightness.

  3. Changes are in Store for Pulping Technology

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1975

    1975-01-01

    The pulp and paper industry are being forced by economic considerations and air pollution regulations to consider alternatives to the use of sulfur systems, be they kraft, acid or neutral sulfite. To meet environmental requirements and combat erosion of profits, modernized non-sulfur pulping methods will increasingly appear on the scene. (BT)

  4. Pulp quality from small-diameter trees.

    Treesearch

    G.C. Myers; S. Kumar; R.R. Gustafson; R.J. Barbour; S.M. Abubakr

    1997-01-01

    Kraft and thermomechanical (TMP) pulps were prepared and evaluated from lodgepole pine and mixed Douglas-fir/western larch sawmill residue chips; lodgepole pine, Douglas-fir, and western larch submerchantable logs; and lodgepole pine, Douglas-fir, and western larch small trees and tops. Kraft pulp from small trees and tops was identical to that from submerchantable...

  5. Changes are in Store for Pulping Technology

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1975

    1975-01-01

    The pulp and paper industry are being forced by economic considerations and air pollution regulations to consider alternatives to the use of sulfur systems, be they kraft, acid or neutral sulfite. To meet environmental requirements and combat erosion of profits, modernized non-sulfur pulping methods will increasingly appear on the scene. (BT)

  6. Pulp and Paper Industry Effluent Management.

    ERIC Educational Resources Information Center

    Gove, George W.

    1978-01-01

    Presents a literature review of wastes from pulp and paper industry, covering publications of 1976-77. This review focuses on: (1) receiving water, toxicity, and effluent characterization; (2) pulping liquor disposal and recovery; and (3) physicochemical and biological treatment. A list of 238 references is also presented. (HM)

  7. Pulp and Paper Industry Effluent Management.

    ERIC Educational Resources Information Center

    Gove, George W.

    1978-01-01

    Presents a literature review of wastes from pulp and paper industry, covering publications of 1976-77. This review focuses on: (1) receiving water, toxicity, and effluent characterization; (2) pulping liquor disposal and recovery; and (3) physicochemical and biological treatment. A list of 238 references is also presented. (HM)

  8. Assessment of pulp vitality: a review.

    PubMed

    Gopikrishna, Velayutham; Pradeep, Gali; Venkateshbabu, Nagendrababu

    2009-01-01

    One of the greatest diagnostic challenges in clinical practice is the accurate assessment of pulp status. This may be further complicated in paediatric dentistry where the practitioner is faced with a developing dentition, traumatized teeth, or young children who have a limited ability to recall a pain history for the tooth in question. A variety of pulp testing approaches exist, and there may be confusion as to their validity or appropriateness in different clinical situations. The aim of this paper is to provide the clinician with a comprehensive review of current pulp testing methods. A key objective is to highlight the difference between sensitivity testing and vitality testing. A biological basis for pulp testing is also provided to allow greater insight into the interpretation of pulp testing results. The rationale for, and methods of, assessing pulpal blood flow are described.

  9. Roles for microbial enzymes in pulp and paper processing

    SciTech Connect

    Kirk, T.K.; Jeffries, T.W.

    1996-10-01

    Microbial enzymes are enabling new technologies for processing pulps and fibers. Xylanases reduce the amount of chemicals required for bleaching; cellulases smooth fibers, enhance drainage, and promote ink removal; lipases reduce pitch; laccases and lignin-degrading enzymes reduce color in effluents, and promote lignin removal. In the future, these and other enzyme-based processes could lead to much cleaner and more efficient pulp and paper processing. Enzymes may also be used to enhance fiber bonding and modify fiber structures. More than 50 million metric tons of paper are produced in North America every year. Globally, paper and paper board production exceeds 270 million metric tons. If even a fraction of this total is enzymatically processed, it could mean a great expansion of the existing enzyme industry. From a fundamental perspective, cellulases, xylanases, and lignin-degrading enzymes are increasingly well understood at a molecular level, and the diversity of these enzyme families is expanding rapidly with the identification of new organisms and direct cloning. Enzyme based analyses and molecular modeling are improving our understanding of the pulp matrix. Novel process developments include the use of co-mediators and the integration of enzymes into commercial environments. This paper will provide an introduction to the symposium and an overview of the field.

  10. Bleach boosting effect of xylanase A from Bacillus halodurans C-125 in ECF bleaching of wheat straw pulp.

    PubMed

    Lin, Xiao-qiong; Han, Shuang-yan; Zhang, Na; Hu, Hui; Zheng, Sui-ping; Ye, Yan-rui; Lin, Ying

    2013-02-05

    Past studies have revealed major difficulties in applications of xylanase in the pulp and paper industry as enzymes isolated from many different species could not tolerate high temperatures or highly alkaline conditions. The thermostable xylanase A from Bacillus halodurans C-125 (C-125 xylanase A) was successfully cloned and expressed in Pichia pastoris with a yield as high as 3361 U/mL in a 2 L reactor. Its thermophilic and basophilic properties (optimal activity at 70 °C and pH 9.0), together with the fact it is cellulase-free, render this enzyme attractive for compatible applications in the pulp and paper industry. The pretreatment of wheat straw pulp with C-125 xylanase A at pH 9.0 and 70 °C for 90 min induced the release of both chromophores (Ab(237), Ab(254), Ab(280)) and hydrophobic compounds (Ab(465)) into the filtrate as well as sugar degradation. Moreover, the addition of 10 U xylanase to 1 g wheat straw pulp (dry weight) as pretreatment improved brightness by 5.2% ISO and decreased the kappa number by 5.0% when followed by hydrogen peroxide bleaching. In addition, compared with two commercial enzymes, Pulpzyme HC and AU-PE89, which are normally incorporated in ECF bleaching of wheat straw pulp, C-125 xylanase A proved to be more effective in enhancing brightness as well as preserving paper strength properties. When evaluating the physical properties of pulp samples, such as tensile index, tearing index, bursting index, and post-color (PC) number, the enzymes involved in pretreating pulps exhibited better or the same performances as chemical treatment. Compared with chemical bleaching, chlorine consumption can be significantly reduced by 10% for xylanase-pretreated wheat straw pulp while maintaining the brightness together with the kappa number at the same level. Scanning electron microscopy revealed significant surface modification of enzyme-pretreated pulp fibers with no marked fiber disruptions.

  11. Ceriporiopsis subvermispora used in delignification of sugarcane bagasse prior to soda/anthraquinone pulping.

    PubMed

    Costa, Sirlene M; Gonçalves, Adilson R; Esposito, Elisa

    2005-01-01

    Sugarcane bagasse was pretreated with the white-rot fungus Ceriporiopsis subvermispora for 30 d of incubation. The solid-state fermentation of 800 g of bagasse was carried out in 20-L bioreactors with an inoculum charge of 250 mg of fungal mycelium/kg of bagasse. The oxidative enzymes manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase (Lac) and the hydrolytic enzyme xylanase (Xyl) were measured by standard methods and related to the fungus's potential for delignification. Among the lignocellulolytic assayed enzymes, Xyl was detected in larger quantity (4478 IU/kg), followed by MnP (236 IU/kg). LiP and Lac were not detected. The results of chemical analysis and mass component loss showed that C. subvermispora was selective to lignin degradation. Pretreated sugarcane bagasse and control pulps were obtained by soda/anthraquinone (AQ) pulping. Pulp yields, kappa number, and viscosity of all pulps were determined by chemical analysis of the samples. Yields of soda/AQ ranged from 46 to 54%, kappa numbers were 15-25, and the viscosity ranged from 3.6 to 7 cP for pulps obtained from pretreated sugarcane bagasse.

  12. Biomechanical and biochemical pulping of sugarcane bagasse with Ceriporiopsis subvermispora fungal and xylanase pretreatments.

    PubMed

    Ramos, J; González, M; Ramírez, F; Young, R; Zúñiga, V

    2001-03-01

    Sugarcane bagasse was pretreated with both the white-rot fungus, Ceriporiopsis subvermispora, and xylanase enzyme for 2 weeks before soda chemithermomechanical (CTMP) and soda chemical (CP) cooking. For fungi-CTMP (BCTMP) and enzyme-fungi-CTMP (EBCTMP), the bagasse, after bio-pretreatment, was cooked with 5% sodium hydroxide, at 130 degrees C for 20 min. For the chemical pulping (CP), after fungi pretreatment (BCP) or after xylanase and fungal pretreatment (EBCP), the bagasse was cooked with 14.5% sodium hydroxide. With the BCTMP, the Klason lignin was reduced, all of the pulp strength properties were increased, and a 28% savings in refining energy consumption was obtained, but the brightness was reduced 5 points compared to the control. With the EBCTMP, the brightness losses were overcome but with a mild reduction in the pulp strength properties compared to the BCTMP. The energy savings were 5% greater than from BCTMP and 33% over the control. The BCP treatment increases somewhat the pulp strength properties, reduces the energy consumption 23%, and reduces the brightness by 9 points compared to the control; however, the kappa no. was 5.5 points higher than the control. EBCP treatment reduces brightness losses and increases the pulp yield 2% compared to the control, but with some reduction in the strength properties compared to BCP.

  13. Mesenchymal dental pulp cells attenuate dentin resorption in homeostasis.

    PubMed

    Zheng, Y; Chen, M; He, L; Marão, H F; Sun, D M; Zhou, J; Kim, S G; Song, S; Wang, S L; Mao, J J

    2015-06-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  14. Mesenchymal Dental Pulp Cells Attenuate Dentin Resorption in Homeostasis

    PubMed Central

    Zheng, Y.; Chen, M.; He, L.; Marão, H.F.; Sun, D.M.; Zhou, J.; Kim, S.G.; Song, S.; Wang, S.L.

    2015-01-01

    Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone–derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal

  15. SOME ASPECTS OF THE CHEMISTRY OF POLYSULFIDE PULPING,

    DTIC Science & Technology

    Kraft pulping with the addition of polysulfide, i.e. polysulfide pulping, is one of the few methods available which can be used to increase the yield...and change the properties of kraft pulp. The chemistry of aqueous polysulfide solutions and the concurrent reactions occurring in polysulfide pulping

  16. Potential uses for peroxymonosulfate in pulping and bleaching

    Treesearch

    Edward L. Springer

    1992-01-01

    Practical and cost-effective uses for peroxymonosulfate can be developed in pulping and bleaching. Peroxymonosulfate pulping produces strong pulps, has lower capital requirements, and is less environmentally troublesome compared with current pulping processes. The cost of oxidant may, however, be somewhat too high for practical use. We discuss means for reducing the...

  17. Investigation of the biotransformation of pentachlorophenol and pulp paper mill effluent decolorisation by the bacterial strains in a mixed culture.

    PubMed

    Singh, Shail; Chandra, R; Patel, D K; Reddy, M M K; Rai, Vibhuti

    2008-09-01

    Mixed culture of two bacterial strains Bacillus sp. and Serratia marcescens showed potential pentachlorophenol (PCP) degradation and decolorisation of pulp paper mill effluent. The physico-chemical quality of pulp paper mill effluent has been analyzed after 168 h incubation period degraded by mixed culture. The study revealed that it has decreased high load of BOD, COD, TS, TDS, TSS, sulphate, phosphate, total nitrogen, total phenols, metals and different salts (i.e. chloride, sodium, nitrate, potassium) at 168 h incubation period. PCP degradation in pulp paper mill effluent was confirmed by HPLC analysis. Mixed culture was found to degrade PCP up to (94%) present in pulp paper mill effluent with 1% glucose and 0.5% peptone (w/v) at 30+/-1 degrees C, pH 8.0+/-0.2 at 120 rpm in 168 h incubation period. The simultaneous release of chloride ion up to 1,200 mg/l at 168 h emphasized the bacterial dechlorination in the medium. The pulp paper mill effluent degradation was also supported by decline in pH, AOX (absorbable organic halides), color, D.O., BOD, COD and PCP. The analysis of pulp paper mill effluent degradation products by GC-MS analysis revealed the formation of low molecular weight compound like 2-chlorophenol (RT=3.8 min) and tetrachlorohydroquinone (RT=11.86 min) from PCP extracted degraded sample. Further, mixed culture may be used for bioremediation of PCP containing pulp paper mill waste in the environment.

  18. A Review on Vital Pulp Therapy in Primary Teeth

    PubMed Central

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed. PMID:25598803

  19. A review on vital pulp therapy in primary teeth.

    PubMed

    Parisay, Iman; Ghoddusi, Jamileh; Forghani, Maryam

    2015-01-01

    Maintaining deciduous teeth in function until their natural exfoliation is absolutely necessary. Vital pulp therapy (VPT) is a way of saving deciduous teeth. The most important factors in success of VPT are the early diagnosis of pulp and periradicular status, preservation of the pulp vitality and proper vascularization of the pulp. Development of new biomaterials with suitable biocompatibility and seal has changed the attitudes towards preserving the reversible pulp in cariously exposed teeth. Before exposure and irreversible involvement of the pulp, indirect pulp capping (IPC) is the treatment of choice, but after the spread of inflammation within the pulp chamber and establishment of irreversible pulpitis, removal of inflamed pulp tissue is recommended. In this review, new concepts in preservation of the healthy pulp tissue in deciduous teeth and induction of the reparative dentin formation with new biomaterials instead of devitalization and the consequent destruction of vital tissues are discussed.

  20. Thermomechanical pulp fiber surface modification for enhancing the interfacial adhesion with polypropylene

    Treesearch

    Sangyeob Lee; Todd F. Shupe; Leslie H. Groom; Chung Y. Hse

    2007-01-01

    Chemical coupling on the thermomechanical pulp (TMP) fiber improved tensile strength of the TMP fiber handsheet and isotactic polypropylene film laminates (TPL). For the maleic anhydride W) with benzoyl peroxide (BPO)a an initiator, tensile strength increaded 52: with the TMP fiber treatment over untreated laminates. The optimum strength properties were obtained with...

  1. Morphology of pulp fiber from hardwoods and influence on paper strength

    Treesearch

    Richard A. Horn

    1978-01-01

    The results of this investigation showed that physical properties of sheets made from hardwood fiber are very dependent upon fiber morphology. Chemical variation of pulp fibers did not exhibit an influence on sheet strength. Of the morphological characteristics investigated, those contributing the most were fiber length, L/T ratio, and fibril angle. Hardwood fines (...

  2. Fractionation of sugar beet pulp by introducing ion-exchange groups

    USDA-ARS?s Scientific Manuscript database

    Sugar beet pulp (SBP) was chemically modified with the goal to utilize this method for the preparation of water-soluble polysaccharides. Yields of the trimethylammoniumhydroxypropylated (TMAHP) polysaccharide fractions prepared under vacuum in absence of NaOH or KOH, as well as their molar masses, w...

  3. The role of sugar beet pulp polysaccharides in the sustainability of the sugar beet industry

    USDA-ARS?s Scientific Manuscript database

    Sugar beet pulp was sequentially extracted with a microwave heating source under pressure to produce pectin, alkaline soluble polysaccharides and cellulose, which was converted into carboxymethyl-cellulose. The solution physical-chemical properties of these polysaccharides were compared to those obt...

  4. Polysaccharides isolated from sugar beet pulp by quaternization under acidic conditions

    USDA-ARS?s Scientific Manuscript database

    Sugar beet pulp was extracted and chemically modified under acidic conditions using glycidyltrimethylammonium chloride in the presence of trifuoroacetic (TFA), HCl or H3PO4. The goal was to find out how the type of acid used and quaternization could affect the yield of soluble polysaccharide, its mo...

  5. The Microbial Challenge to Pulp Regeneration

    PubMed Central

    Fouad, A.F.

    2011-01-01

    Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens. PMID:21677080

  6. The microbial challenge to pulp regeneration.

    PubMed

    Fouad, A F

    2011-07-01

    Pulp regeneration is considered in cases where the dental pulp has been destroyed because of microbial irritation. Diverse oral and food-borne micro-organisms are able to invade the pulp space, form biofilm on canal walls, and infiltrate dentinal tubules. Prior to pulp regeneration procedures, the pulp space and dentinal walls need to be sufficiently disinfected to allow for and promote regeneration. The necessary level of disinfection is likely higher than that accepted for traditional endodontic therapy, because in traditional techniques the mere lowering of bacterial loads and prevention of bacterial access to periapical tissues is conducive to healing. Moreover, several of the non-specific antimicrobials used in traditional endodontic therapy may cause significant changes in remaining dentin that interfere with its inherent potential to mediate regeneration. Non-specific antimicrobials also suppress all microbial taxa, which may allow residual virulent micro-organisms to preferentially repopulate the pulp space. Therefore, it is important for endodontic pathogens to be studied by molecular methods that allow for a broad depth of coverage. It is then essential to determine the most effective protocols to disinfect the pulp space, with minimal disruption of remaining dentin. These protocols include the topical use of effective antibiotics, including newer agents that have demonstrated efficacy against endodontic pathogens.

  7. Biomechanical pulping: A mill-scale evaluation

    SciTech Connect

    Akhtar, M.; Scott, G.M.; Swaney, R.E.; Shipley, D.F.

    1999-07-01

    Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory scale. In an effort to scale-up biomechanical pulping to an industrial level, fifty tons of spruce wood chips were inoculated with the best biopulping fungus in a continuous operation and stored in the form of an outdoor chip pile for two weeks. The pile was ventilated with conditioned air to maintain the optimum growth temperature and moisture throughout the pile. The control and fungus-treated chips were refined through a thermomechanical pulp mill (TMP) producing lightweight coated paper. The fungal pretreatment saved 33% electrical energy and improved paper strength properties significantly compared to the control. Since biofibers were stronger than the conventional TMP fibers, the authors were able to reduce the amount of bleached softwood kraft pulp by at least 5% in the final product. Fungal pretreatment reduced brightness, but brightness was restored to the level of bleached control with 60% more hydrogen peroxide. The economics of biomechanical pulping look attractive.

  8. A New Technology for Treating Pulp Waste with Plasma

    NASA Astrophysics Data System (ADS)

    Feng, Xiaozhen; Tian, Zhongyu

    2009-10-01

    New methods for both the treatment of pulp waste liquor called black liquor (BL) and the recovery of chemicals by using plasma, and the concentration of BL with the freezing technique were developed. The new methods aiming at the pilot plant scale are described and the experiments in a small-scale research facility for demonstration and test are presented. The energy consumption for treating waste liquid is 1 kg/kWh. Plasma processing can reduce the costs for treatment and eliminate pollution.

  9. Optimization of pulping conditions of abaca. An alternative raw material for producing cellulose pulp.

    PubMed

    Jiménez, L; Ramos, E; Rodríguez, A; De la Torre, M J; Ferrer, J L

    2005-06-01

    The influence of temperature (150-170 degrees C), pulping time (15-45 min) and soda concentration (5-10%) in the pulping of abaca on the yield, kappa, viscosity, breaking length, stretch and tear index of pulp and paper sheets, was studied. Using a factorial design to identify the optimum operating conditions, equations relating the dependent variables to the operational variables of the pulping process were derived that reproduced the former with errors lower than 25%. Using a high temperature, and a medium time and soda concentration, led to pulp that was difficult to bleach (kappa 28.34) but provided acceptable strength-related properties (breaking length 4728 m; stretch 4.76%; tear index 18.25 mN m2/g), with good yield (77.33%) and potential savings on capital equipment costs. Obtaining pulp amenable to bleaching would entail using more drastic conditions than those employed in this work.

  10. Vital Pulp Therapy—Current Progress of Dental Pulp Regeneration and Revascularization

    PubMed Central

    Zhang, Weibo; Yelick, Pamela C.

    2010-01-01

    Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization. PMID:20454445

  11. Vital pulp therapy-current progress of dental pulp regeneration and revascularization.

    PubMed

    Zhang, Weibo; Yelick, Pamela C

    2010-01-01

    Pulp vitality is extremely important for the tooth viability, since it provides nutrition and acts as biosensor to detect pathogenic stimuli. In the dental clinic, most dental pulp infections are irreversible due to its anatomical position and organization. It is difficult for the body to eliminate the infection, which subsequently persists and worsens. The widely used strategy currently in the clinic is to partly or fully remove the contaminated pulp tissue, and fill and seal the void space with synthetic material. Over time, the pulpless tooth, now lacking proper blood supply and nervous system, becomes more vulnerable to injury. Recently, potential for successful pulp regeneration and revascularization therapies is increasing due to accumulated knowledge of stem cells, especially dental pulp stem cells. This paper will review current progress and feasible strategies for dental pulp regeneration and revascularization.

  12. Recent Advances in Pulp Capping Materials: An Overview

    PubMed Central

    Qureshi, Asma; E., Soujanya; Nandakumar; Pratapkumar; Sambashivarao

    2014-01-01

    Emphasis has shifted from the “doomed” organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of various pulp capping materials. The aim of this article is to summarize and discuss about the various and newer pulp capping materials used for protection of the dentin-pulp complex. PMID:24596805

  13. Method for Improving Separation of Carbohydrates from Wood Pulping Liquors and Wood or Biomass Hydrolysis Liquors

    SciTech Connect

    Compere, A L; Marcoccia, B S; Elliott, J

    2012-08-31

    Work with industrial partners to perform the studies needed to commercialize U.S. patent 7,699,958 for separation of carbohydrates from wood pulping liquors and wood or biomass hydrolysis liquors. These include: 1) selection of the best pulp mill liquor withdrawal sites, 2) additional purification or enzyme hydrolysis required to obtain acceptable sugar feedstocks, 3) and work with partners to optimize the stream and purification methods to provide acceptable feedstocks for algal fuels and industrial chemicals production, and 4) preparation of samples large enough for testing by downstream partners.

  14. HIGHLY ENERGY EFFICIENT D-GLU (DIRECTED-GREEN LIQ-UOR UTILIZATION) PULPING

    SciTech Connect

    Lucia, Lucian A

    2013-04-19

    Purpose: The purpose of the project was to retrofit the front end (pulp house) of a commercial kraft pulping mill to accommodate a mill green liquor (GL) impregna-tion/soak/exposure and accrue downstream physical and chemical benefits while prin-cipally reducing the energy footprint of the mill. A major player in the mill contrib-uting to excessive energy costs is the lime kiln. The project was intended to offload the energy (oil or natural gas) demands of the kiln by by-passing the causticization/slaking site in the recovery area and directly using green liquor as a pulping medium for wood. Scope: The project was run in two distinct, yet mutually compatible, phases: Phase 1 was the pre-commercial or laboratory phase in which NC State University and the Insti-tute of Paper Science and Technology (at the Georgia Institute of Technology) ran the pulping and associated experiments, while Phase 2 was the mill scale trial. The first tri-al was run at the now defunct Evergreen Pulp Mill in Samoa, CA and lead to a partial retrofit of the mill that was not completed because it went bankrupt and the work was no longer the low-hanging fruit on the tree for the new management. The second trial was run at the MeadWestvaco Pulp Mill in Evedale, TX which for all intents and pur-poses was a success. They were able to fully retrofit the mill, ran the trial, studied the pulp properties, and gave us conclusions.

  15. Pulp Revascularization: A Literature Review.

    PubMed

    Araújo, Pollyana Rodrigues de Souza; Silva, Luciano Barreto; Neto, Alexandrino Pereira Dos Santos; Almeida de Arruda, José Alcides; Álvares, Pâmella Recco; Sobral, Ana Paula Veras; Júnior, Severino Alves; Leão, Jair Carneiro; Braz da Silva, Rodivan; Sampaio, Gerhilde Callou

    2017-01-01

    Reestablishing blood flow and allowing the continuation of root development are some of the objectives of pulp revascularization. This procedure is currently indicated for teeth with incomplete root formation as an alternative to the traditional treatment of apecification, which consists of inserting calcium hydroxide paste into the root canal for a determined time period in order to induce the formation of a calcified barrier. Although it is considered as the most classically employed therapy, the permanence of the paste for long time periods may lead to the weakening of the root due to hygroscopic properties, as well as proteolytic activities of calcium hydroxide. Therefore, there has been a permanent search for alternatives which allow the full development of immature teeth. Revascularization has emerged as such an alternative, and a range of treatment protocols can be found in the scientific literature. The aim of this paper is to accomplish a literature review concerning this issue.

  16. A New Method for Evaluating the Diffusion of Ca(2+) and OH(-) Ions through Coronal Dentin into the Pulp.

    PubMed

    Gandolfi, Maria Giovanna

    2012-01-01

    Ca(OH)(2)-containing/forming materials are conventionally used for indirect pulp-capping and are theoretically able to release Ca(2+) and OH(-) ions for hydrolytic dissociation. However, no evidence exists for ion diffusion through the remaining coronal dentin. The aim of this study was to design an innovative experimental set-up to test the ability of Ca(OH)(2)-containing and Ca(OH)(2)-forming pulp-capping materials to generate pulpward Ca(2) and OH(-) ion fluxes through coronal dentin after indirect pulp-capping in vitro. Standardized class 1 cavities were prepared in erupted sound human molars. Pulp tissue was excised. A coronal Remaining Dentin Thickness (RTD) (1±0.2 mm thick) was prepared within an occlusal-to-pulp cavity system (coronal RD system). The whole system/sample was treated with 17% EDTA to remove the smear layer and the external surface was covered by nail varnish. Indirect pulp-capping was performed on coronal RDT using a conventional pulp-capping material covered by a glass ionomer cement, a composite and nail varnish. Chemically different Ca(OH)(2) materials were used to test the reliability of the set-up. The leached Ca(2+) and OH(-) ions were measured using ion-selective electrodes after soaking for 3 hours, 24 hours, and 7 days in deionized water (10 mL, 37°C). Calcium ions were detected and a rise in pH was observed in the treated water after a few hours for all tested materials. The experimental set-up proved to be an easy and effective method for testing the different Ca(OH)(2)-containing and Ca(OH)(2)-forming materials ability to induce a pulpward flux of calcium and hydroxyl ions through coronal remaining dentin after indirect pulp-capping. The new system will allow the screening of current pulp-capping materials.

  17. Unleashing the potential of ligninolytic bacterial contributions towards pulp and paper industry: key challenges and new insights.

    PubMed

    Priyadarshinee, Rashmi; Kumar, Anuj; Mandal, Tamal; Dasguptamandal, Dalia

    2016-12-01

    Lignocellulose biomass predominantly constitutes the main feedstock for pulp and paper industry. Though some products of pulp and paper industry require the presence of lignin content, for most of the useful products formation lies in the efficient and selective removal of lignin component to make use of the intact cellulose fraction during the pretreatment of pulp. Lignin is a recalcitrant heteropolymer comprised of several complex stable bonds and linkages. The chemicals or intense energy processes used for delignification process release the hazardous chemicals compounds in the wastewater which cause toxicity and environmental pollution. The implementation of bacterial species has elucidated an effective approach in the generation of value-added products while degrading lignin from pulp biomass as well as detoxification of effluent. The direct use of bacterial cells in lignocellulose biomass and wastewater streams is promising as it outperforms the practical and technical constraints largely confronted by fungal and enzymatic means. The present review paper thus unleashed the potential of ligninolytic bacteria towards delignification of pulp biomass and treatment of effluent together with bioconversion of biomass and lignin into value-added products. Graphical abstract Schematic illustration of potential possible contribution of ligninolytic bacteria towards pulp and paper industry.

  18. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration

    PubMed Central

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-01-01

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively. PMID:26729180

  19. Influence of process variables on the properties of laccase biobleached pulps.

    PubMed

    Martin-Sampedro, Raquel; Miranda, Jesús; García-Fuentevilla, Luisa L; Hernández, Manuel; Arias, Maria E; Diaz, Manuel J; Eugenio, Maria E

    2015-01-01

    A laccase stage can be used as a pre-treatment of a standard chemical bleaching sequence to reduce environmental concerns associated to this process. The importance of each independent variable and its influence on the properties of the bleached pulp have been studied in depth in this work, using an adaptive network-based fuzzy inference system (ANFIS) with four independent variables (laccase, buffer, mediator and oxygen) as input. Eucalyptus globulus kraft pulp was biobleached using a laccase from Pycnoporus sanguineus and a natural mediator (acetosyringone). Later, an alkaline extraction and a hydrogen peroxide treatment were applied. Most biobleaching processes showed a decrease in kappa number and an increase in brightness with no significant impact on the viscosity values, compared with the control. Oxygen was the variable with the smallest influence on the final pulp properties while the laccase and buffer solution showed a significant influence.

  20. Decolorization of sugar syrups using commercial and sugar beet pulp based activated carbons.

    PubMed

    Mudoga, H L; Yucel, H; Kincal, N S

    2008-06-01

    Sugar syrup decolorization was studied using two commercial and eight beet pulp based activated carbons. In an attempt to relate decolorizing performances to other characteristics, surface areas, pore volumes, bulk densities and ash contents of the carbons in the powdered form; pH and electrical conductivities of their suspensions and their color adsorption properties from iodine and molasses solution were determined. The color removal capabilities of all carbons were measured at 1/100 (w/w) dosage, and isotherms were determined on better samples. The two commercial activated carbons showed different decolorization efficiencies; which could be related to their physical and chemical properties. The decolorization efficiency of beet pulp carbon prepared at 750 degrees C and activated for 5h using CO2 was much better than the others and close to the better one of the commercial activated carbons used. It is evident that beet pulp is an inexpensive potential precursor for activated carbons for use in sugar refining.

  1. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

    PubMed

    Srinivasan, S V; Murthy, D V S; Swaminathan, T

    2012-07-01

    The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies.

  2. Treatment of the Bleaching Effluent from Sulfite Pulp Production by Ceramic Membrane Filtration.

    PubMed

    Ebrahimi, Mehrdad; Busse, Nadine; Kerker, Steffen; Schmitz, Oliver; Hilpert, Markus; Czermak, Peter

    2015-12-31

    Pulp and paper waste water is one of the major sources of industrial water pollution. This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes were developed to reduce the chemical oxygen demand (COD) and remove residual lignin from the effluent flow during sulfite pulp production. A comparison of the ceramic membranes in terms of separation efficiency and performance revealed that the two-stage process configuration with microfiltration followed by ultrafiltration was most suitable for the efficient treatment of the alkaline bleaching effluent tested herein, reducing the COD concentration and residual lignin levels by more than 35% and 70%, respectively.

  3. Kraft pulp biobleaching using an extracellular enzymatic fluid produced by Pycnoporus sanguineus.

    PubMed

    Eugenio, M E; Santos, S M; Carbajo, J M; Martín, J A; Martín-Sampedro, R; González, A E; Villar, J C

    2010-03-01

    The aim of this work was to obtain a LMS pre-treatment applicable to industrial TCF bleaching. Kraft pulp from Eucalyptus globulus was treated at 40 degrees C/pH 3 and 60 degrees C/pH 5 for 1h using an extracellular fluid enriched in laccase produced by Pycnoporus sanguineus and acetosyringone as mediator (HBT was used as a control mediator) (L). Alkaline extraction (E) and hydrogen peroxide (P) stages were then assayed. The LEP alternative was an efficient sequence to bleach kraft pulp since the enzymatic pre-treatment boosted the subsequent chemical bleaching. The best L pre-treatment was obtained with laccase-acetosyringone at 40 degrees C/pH 3. It reduces kappa number and hexenuronic acids, increases pulp viscosity, lowers hydrogen peroxide consumption down to an 87.4% (94.0% without L) and enhances brightness up to a 59% ISO (51% ISO without L).

  4. GHGRP Pulp and Paper Sector Industrial Profile

    EPA Pesticide Factsheets

    EPA's Greenhouse Gas Reporting Program periodically produces detailed profiles of the various industries that report under the program. The profiles available for download below contain detailed analyses for the Pulp and Paper industry.

  5. Pulp and paper program fact sheets

    SciTech Connect

    1995-07-01

    Summaries are presented of Argonne technology transfer research projects in: sustainable forest management, environmental performance, energy performance, improved capital effectiveness, recycling, and sensors and controls. Applications in paper/pulp industry, other industries, etc. are covered.

  6. Indirect pulp therapy and stepwise excavation.

    PubMed

    Bjørndal, Lars

    2008-01-01

    Various treatment concepts have been suggested to solve the deep carious lesion dilemma. Recent systematic reviews are presented. Their conclusions are based on very few studies, and the main message is that optimal randomized clinical studies are lacking. Observational studies on indirect pulp treatment and stepwise excavation demonstrate that these treatments avoid pulp exposures, but it cannot be said which approach is best. A less invasive modified stepwise excavation approach is described, focusing on changing on active lesion into on arrested lesion even without performing an excavation close to the pulp. In Denmark and Sweden a randomized clinical multi-center trial is currently taking place, the Caries and Pulp (CAP) trial. This trial is investigating the effects of stepwise excavation over 2 visits versus 1 complete excavation of deep caries in permanent teeth. Guidelines for treatment are presented.

  7. Indirect pulp therapy and stepwise excavation.

    PubMed

    Bjørndal, Lars

    2008-07-01

    Various treatment concepts have been suggested to solve the deep carious lesion dilemma. Recent systematic reviews are presented. Their conclusions are based on very few studies, and the main message is that optimal randomized clinical studies are lacking. Observational studies on indirect pulp treatment and stepwise excavation demonstrate that these treatments avoid pulp exposures, but it cannot be said which approach is best. A less invasive modified stepwise excavation approach is described, focusing on changing an active lesion into an arrested lesion even without performing an excavation close to the pulp. In Denmark and Sweden a randomized clinical multi-center trial is currently taking place, the Caries and Pulp (CAP) trial. This trial is investigating the effects of stepwise excavation over 2 visits versus 1 complete excavation of deep caries in permanent teeth. Guidelines for treatment are presented.

  8. Minimizing Excessive Stimulus during Electric Pulp Testing.

    PubMed

    Kim, D; Nam, K; Lee, S; Kim, S

    2005-01-01

    Electric pulp test is a method to examine the vitality of dental pulp using the electrical stimulation. During the pulp test, the current stimulates intradental nerve, and give severe pain to patients. Some studies were accomplished to measure the responses of subjects by stimulating over the sensory threshold. But these studies were focused on the time delay of subject's response after stimulating over the threshold. The purpose of this study was first to measure the excessive stimulation time during pulp testing by means of EMG in anterior belly of digastric muscle, voice, and finger movement, secondly, to determine whether the excessive stimulation time could be reduced by the specially designed automatic circuit breaker on the basis of EMG signal.

  9. The role of cytokines in pulp inflammation.

    PubMed

    Kokkas, A; Goulas, A; Stavrianos, C; Anogianakis, G

    2011-01-01

    Pulpitis is a typical inflammatory disease of dental pulp, characterized by the local accumulation of inflammatory mediators, including cytokines and chemokines. In addition to serving as intercellular messengers mediating the inflammatory response, cytokines and chemokines induce the expression and stimulate the activity of molecular and cellular agents which participate actively in destructive and reparative processes in the pulp. It is the balance between these processes which eventually determines the extent of pulp inflammation and the viability of the affected tooth. Over the last decade, a number of studies have attempted to correlate cytokine gene expression in the pulp with various stages of inflammation, with possible diagnostic applications in mind. A small survey of relevant information is presented in this paper.

  10. Pulp consistency determined by a combination of optical and acoustical measurement techniques

    NASA Astrophysics Data System (ADS)

    Törmänen, Matti; Niemi, Jan; Löfqvist, Torbjörn; Myllylä, Risto

    2006-04-01

    In this study, methods based on ultrasonic attenuation and optical time-of-flight measurements are used simultaneously in determining both the fibres and fines mass fractions, respectively, of a cellulose pulp fibre suspension. The optical measurements are done by a laser radar and the acoustical measurements are based on ultrasonic attenuation measurements in a pulse-echo set-up. Two kinds of long-fibre fractions are studied, thermo-mechanical pulp and chemical softwood pulp. Fibre and fines mass fraction ranges are 0.25-1.0% and 0-0.75%, respectively. The results show that the fibres are the predominant source for absorption and scattering of ultrasonic waves and are thus mainly contributing to the attenuation of ultrasound in the pulp. It is also found that the fines are the predominant source for optical scattering and fines are thus mainly contributing to the propagation delay of the light pulse in the laser radar set-up. By combining the ultrasonic attenuation and the optical time-of-flight measurements, it is shown that the mass fraction of fines and the mass fraction of fibres in a pulp sample could be determined, respectively.

  11. Role of pulp in flavor release and sensory perception in orange juice.

    PubMed

    Rega, Barbara; Fournier, Nicole; Nicklaus, Sophie; Guichard, Elisabeth

    2004-06-30

    This work elucidates the role of suspended solids in sensorial perception and flavor release in orange juice. The coarsest pulp (insoluble particles with a diameter of >2 microm) accounted for two major physicochemical effects in orange juice samples: it retained large amounts of aroma compounds, including terpenes and aldehydes, and modified the rheological properties of the juice matrix. These phenomena strongly affected the chemical composition of the vapor phase in the juice samples. On the other hand, orange juice cloud (finest insoluble particles with a diameter of <2 microm) also showed a strong retention effect on ethyl butanoate or hexanal, probably due to the occurrence of molecular interactions with cloud macromolecules. The amount and the size of the suspended solids critically modified not only the texture perception but also the odor and the overall flavor perception, including the "freshly squeezed" and the "artificial flavor" descriptors. The addition of a natural pulp to low-pulp juices increases the fresh orange juice character, a finding that is explained by both physicochemical (fresh pulp contains high amounts of key aroma compounds, including acetaldehyde and mono- and sesquiterpenes) and cognitive effects, mainly due to the tactile properties of the pulp.

  12. A Hyaluronan-Based Scaffold for the in Vitro Construction of Dental Pulp-Like Tissue

    PubMed Central

    Ferroni, Letizia; Gardin, Chiara; Sivolella, Stefano; Brunello, Giulia; Berengo, Mario; Piattelli, Adriano; Bressan, Eriberto; Zavan, Barbara

    2015-01-01

    Dental pulp tissue supports the vitality of the tooth, but it is particularly vulnerable to external insults, such as mechanical trauma, chemical irritation or microbial invasion, which can lead to tissue necrosis. In the present work, we present an endodontic regeneration method based on the use of a tridimensional (3D) hyaluronan scaffold and human dental pulp stem cells (DPSCs) to produce a functional dental pulp-like tissue in vitro. An enriched population of DPSCs was seeded onto hyaluronan-based non-woven meshes in the presence of differentiation factors to induce the commitment of stem cells to neuronal, glial, endothelial and osteogenic phenotypes. In vitro experiments, among which were gene expression profiling and immunofluorescence (IF) staining, proved the commitment of DPSCs to the main components of dental pulp tissue. In particular, the hyaluronan-DPSCs construct showed a dental pulp-like morphology consisting of several specialized cells growing inside the hyaluronan fibers. Furthermore, these constructs were implanted into rat calvarial critical-size defects. Histological analyses and gene expression profiling performed on hyaluronan-DPSCs grafts showed the regeneration of osteodentin-like tissue. Altogether, these data suggest the regenerative potential of the hyaluronan-DPSC engineered tissue. PMID:25739081

  13. Missing Concepts in De Novo Pulp Regeneration.

    PubMed

    Huang, G T-J; Garcia-Godoy, F

    2014-08-01

    Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been developed--termed revitalization or revascularization. Histologic studies from animal and human teeth receiving revitalization have shown that pulp regeneration is difficult to achieve. In tissue engineering, there are 2 approaches to regeneration tissues: cell based and cell free. The former involves transplanting exogenous cells into the host, and the latter does not. Revitalization belongs to the latter approach. A number of crucial concepts have not been well discussed, noted, or understood in the field of regenerative endodontics in terms of pulp/dentin regeneration: (1) critical size defect of dentin and pulp, (2) cell lineage commitment to odontoblasts, (3) regeneration vs. repair, and (4) hurdles of cell-based pulp regeneration for clinical applications. This review article elaborates on these missing concepts and analyzes them at their cellular and molecular levels, which will in part explain why the non-cell-based revitalization procedure is difficult to establish pulp/dentin regeneration. Although the cell-based approach has been proven to regenerate pulp/dentin, such an approach will face barriers--with the key hurdle being the shortage of the current good manufacturing practice facilities, discussed herein. © International & American Associations for Dental Research.

  14. Missing Concepts in De Novo Pulp Regeneration

    PubMed Central

    Huang, G.T.-J.; Garcia-Godoy, F.

    2014-01-01

    Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been developed—termed revitalization or revascularization. Histologic studies from animal and human teeth receiving revitalization have shown that pulp regeneration is difficult to achieve. In tissue engineering, there are 2 approaches to regeneration tissues: cell based and cell free. The former involves transplanting exogenous cells into the host, and the latter does not. Revitalization belongs to the latter approach. A number of crucial concepts have not been well discussed, noted, or understood in the field of regenerative endodontics in terms of pulp/dentin regeneration: (1) critical size defect of dentin and pulp, (2) cell lineage commitment to odontoblasts, (3) regeneration vs. repair, and (4) hurdles of cell-based pulp regeneration for clinical applications. This review article elaborates on these missing concepts and analyzes them at their cellular and molecular levels, which will in part explain why the non-cell-based revitalization procedure is difficult to establish pulp/dentin regeneration. Although the cell-based approach has been proven to regenerate pulp/dentin, such an approach will face barriers—with the key hurdle being the shortage of the current good manufacturing practice facilities, discussed herein. PMID:24879576

  15. Is pulp regeneration necessary for root maturation?

    PubMed

    Nosrat, Ali; Li, Kevin L; Vir, Kunwar; Hicks, M Lamar; Fouad, Ashraf F

    2013-10-01

    True regeneration of the dental pulp-dentin complex in immature teeth with necrotic pulps has not been shown histologically. It is not known to what extent this true tissue regeneration is necessary to achieve clinically acceptable outcomes. This case report describes the treatment of a patient with an immature maxillary right central incisor with a history of impact trauma and enamel-dentin crown fracture. A diagnosis of pulp necrosis with acute apical abscess was established. A regenerative endodontic protocol that used a paste containing Augmentin for 5 weeks as an intracanal medicament was used. Follow-ups at 9, 12, 17, and 31 months revealed complete osseous healing of the periapical lesion and formation of the root apex, but without increase in root length. Clinically, the tooth was functional, asymptomatic, and nonresponsive to pulp vitality tests. The crown discolored over time. On reentering the root canal, no tissues were observed under magnification inside the root canal space. The root canal treatment was completed with mineral trioxide aggregate obturation. Augmentin might be an acceptable choice for root canal disinfection in regenerative endodontic procedures. The protocol for regenerative endodontic treatment is not predictable for pulp-dentin regeneration. Formation of the root apex is possible without pulp regeneration. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Xylanase and ultrasound assisted pulping of wheat straw.

    PubMed

    Dedhia, Bhavin S; Csoka, Levente; Rathod, Virendra K

    2012-10-01

    In the present work, a novel approach to pretreat wheat straw pulping was investigated with ultrasound and xylanase to achieve maximum reduction in lignin content. Sequential xylanase pretreatment and alkaline pulping was found to reduce kappa number by 0.31 to 4.84 % compared with only alkaline pulping alone at different pulping conditions. Although Klason lignin of ultrasound-treated straw was found to be 7.37 % less compared with untreated straw, sequential ultrasound pretreatment and alkaline pulping could not show any significant reduction in kappa number compared with alkaline pulping alone. Also, sequential xylanase and ultrasound pretreatment could not show any significant reduction in kappa number. Total yield of the pulp was found to be less in ultrasound-assisted processing compared with both alkaline pulping alone and sequential xylanase pretreatment and alkaline pulping.

  17. Hydrothermal carbonization of autoclaved municipal solid waste pulp and anaerobically treated pulp digestate

    USDA-ARS?s Scientific Manuscript database

    In this study, the autoclaved organic fraction of municipal solid waste pulp (OFMSW) and the digestate from OFMSW pulp after anaerobic digestion (AD) were processed by hydrothermal carbonization (HTC) at 200, 250, and 300 °C for 30 min and 2 h. The focus of this work was to evaluate the potential fo...

  18. SEM evaluation of pulp reaction to different pulp capping materials in dog’s teeth

    PubMed Central

    Asgary, Saeed; Parirokh, Masoud; Eghbal, Mohammad Jafar; Ghoddusi, Jamileh

    2006-01-01

    Introduction: This investigation evaluates the effects of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and calcium enriched mixture (CEM) as pulp capping materials on dental pulp tissues. Materials and Methods: The experimental procedures were performed on eighteen intact dog canine teeth. The pulps were exposed. Cavities were randomly filled with CEM, MTA, or CH followed by glass ionomer filling. After 2 months, animals were sacrificed, each tooth was sectioned into halves, and the interface between each capping material and pulp tissue was evaluated by scanning electron microscope (SEM) in profile view of the specimens. Results: Dentinal bridge formation as the most characteristic reaction was resulted from SEM observation in all examined groups. Odontoblast-like cells were formed and create dens collagen network, which was calcified gradually by deposition of calcosphirit structures to form newly dentinal bridge. Conclusion: Based on the results of this in vivo study, it was concluded that these test materials are able to produce calcified tissue in underlying pulp in the case of being used as a pulp capping agent. Additionally, it appears that CEM has the potential to be used as a direct pulp capping material during vital pulp therapy. PMID:24379876

  19. Dental Pulp Cell Behavior in Biomimetic Environments.

    PubMed

    Smith, J G; Smith, A J; Shelton, R M; Cooper, P R

    2015-11-01

    There is emerging recognition of the importance of a physiologically relevant in vitro cell culture environment to promote maintenance of stem cells for tissue engineering and regenerative medicine purposes. In vivo, appropriate cellular cues are provided by local tissue extracellular matrix (ECM), and these are not currently recapitulated well in vitro using traditional cultureware. We therefore hypothesized that better replication of the in vivo environment for cell culture and differentiation could be achieved by culturing dental pulp cells with their associated ECM. Primary dental pulp cells were subsequently seeded onto pulp-derived ECM-coated cultureware. While at up to 24 h they exhibited the same level of adherence as those cells seeded on tissue culture-treated surfaces, by 4 d cell numbers and proliferation rates were significantly decreased in cells grown on pulp ECM compared with controls. Analysis of stem cell and differentiation marker transcripts, as well as Oct 3/4 protein distribution, supported the hypothesis that cells cultured on ECM better maintained a stem cell phenotype compared with those cultured on standard tissue culture-treated surfaces. Subsequent differentiation analysis of cells cultured on ECM demonstrated that they exhibited enhanced mineralization, as determined by alizarin red staining and mineralized marker expression. Supplementation of a 3% alginate hydrogel with pulp ECM components and dental pulp cells followed by differentiation induction in mineralization medium resulted in a time-dependent mineral deposition at the periphery of the construct, as demonstrated histologically and using micro-computed tomography analysis, which was reminiscent of tooth structure. In conclusion, data indicate that culture of pulp cells in the presence of ECM better replicates the in vivo environment, maintaining a stem cell phenotype suitable for downstream tissue engineering applications. © International & American Associations for Dental

  20. Activity-guided identification of acetogenins as novel lipophilic antioxidants present in avocado pulp (Persea americana).

    PubMed

    Rodríguez-Sánchez, Dariana; Silva-Platas, Christian; Rojo, Rocío P; García, Noemí; Cisneros-Zevallos, Luis; García-Rivas, Gerardo; Hernández-Brenes, Carmen

    2013-12-30

    Avocado fruit is a rich source of health-related lipophilic phytochemicals such as monounsaturated fatty acids, tocopherols, carotenes, acetogenins and sterols. However, limited information is available on the contribution of specific phytochemicals to the overall antioxidant capacity (AOC) of the fruit. Centrifugal partition chromatography was used as fractionation tool, guided by an in vitro chemical assay of oxygen radical absorbance capacity (ORAC). Subsequent experiments focused on isolation and characterization of the chemical nature of the main contributors to lipophilic AOC of avocado pulp. ORAC values obtained for acetogenins were contrasted with results from an isolated kidney mitochondria membrane lipid peroxidation bioassay. The present study established that lipophilic AOC of the pulp was significantly higher than its hydrophilic AOC. Our results confirmed the presence of acetogenins in the fractions with highest lipophilic AOC, and for the first time linked them as contributors to lipophilic-ORAC values. Further HPLC-PDA/MS-TOF analysis led to structural elucidation of two novel acetogenins, not previously reported as present in avocado pulp, along with five already known related-compounds. Antioxidant properties observed for avocado pulp acetogenins by the ORAC assay suggested that, in the presence of an emulsifying agent, acetogenins could serve as novel lipophilic antioxidants in a food matrix. Results from isolated mitochondria lipid peroxidation bioassay, indicated that L-ORAC values which may have relevance for food matrix applications, should not be interpreted to have a direct relevance in health-related claims, compounds need to be evaluated considering the complexity of biological systems.

  1. Fiber surface characterization of old newsprint pulp deinked by combining hemicellulase with laccase-mediator system.

    PubMed

    Xu, Q H; Wang, Y P; Qin, M H; Fu, Y J; Li, Z Q; Zhang, F S; Li, J H

    2011-06-01

    Deinking of old newsprint (ONP) by combining hemicellulase with laccase-mediator system (LMS) was investigated, and surface chemical composition and fiber morphology changes during the deinking process were studied by electron spectroscopy for chemical analysis (ESCA), contact angle (CA), attenuated total reflectance fourier transform infrared spectrometry (ATR-FTIR), fiber quality analyzer (FQA), and environmental scanning electronic microscopy (ESEM). Results showed that, compared to the pulp deinked with hemicellulase or LMS individually, effective residual ink concentration (ERIC) was lower for the hemicellulase/LMS-deinked pulp. This indicated that there is a synergistic deinking effect between hemicellulase and LMS. It was found that O/C ratio of the fiber surface increased and the surface coverage of lignin decreased during the hemicellulase/LMS deinking process. The contact angle of the hemicellulase/LMS-deinked pulp was lower than that of pulps deinked with each individual enzyme. ESEM observations showed that more fibrils appeared on the fiber surface due to synergistic treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Dental pulp stem cells in regenerative dentistry.

    PubMed

    Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

    2011-01-01

    Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

  3. Epigenetic regulation in dental pulp inflammation

    PubMed Central

    Hui, T; Wang, C; Chen, D; Zheng, L; Huang, D; Ye, L

    2016-01-01

    Dental caries, trauma, and other possible factors could lead to injury of the dental pulp. Dental infection could result in immune and inflammatory responses mediated by molecular and cellular events and tissue breakdown. The inflammatory response of dental pulp could be regulated by genetic and epigenetic events. Epigenetic modifications play a fundamental role in gene expression. The epigenetic events might play critical roles in the inflammatory process of dental pulp injury. Major epigenetic events include methylation and acetylation of histones and regulatory factors, DNA methylation, and small non-coding RNAs. Infections and other environmental factors have profound effects on epigenetic modifications and trigger diseases. Despite growing evidences of literatures addressing the role of epigenetics in the field of medicine and biology, very little is known about the epigenetic pathways involved in dental pulp inflammation. This review summarized the current knowledge about epigenetic mechanisms during dental pulp inflammation. Progress in studies of epigenetic alterations during inflammatory response would provide opportunities for the development of efficient medications of epigenetic therapy for pulpitis. PMID:26901577

  4. [Pulp treatment of young permanent teeth after traumatic dental injury].

    PubMed

    Qin, Man

    2009-06-01

    Dental trauma could be largely classified into three groups: Hard tissue injuries, pulp injuries and periodontal tissue injuries. Since pulp injuries are reported in tooth fracture, displacement and avulsion, it is commonly thought that pulp injuries were involved in almost every type of dental injuries. The sequelae of pulp tissue after dental injuries include pulp survival, pulp calcification and pulp necrosis. Dental trauma mostly occurs in 7-15 year-old children. The treatment and prognosis of dental trauma in children are more complicated than those in adults because of the developmental nature of the young permanent teeth. The evaluation of pulp damage and treatment after dental injuries in growing young permanent teeth are discussed in this paper.

  5. [Mineral trioxide aggregate in the pulp capping treatment tooth].

    PubMed

    Góra, Monika; Nowicka, Alicja; Łagocka, Ryta; Buczkowska-Radlińska, Jadwiga; Lipski, Mariusz; Górski, Maciej

    2008-01-01

    Therapeutic procedure for the treatment of tooth pulp exposure or pulp injury is a conservative treatment using direct pulp capping. Achievements to date in biological pulp treatment and the case of treatment of tooth pulp injury by odontotropic preparation Mineral Trioxide Aggregate (ProRoot MTA, Dentsply Maillefer, U.S.A.) has been presented in this paper. Applied treatment consisted in total processing of cariotic cavity, covering the place of cavity with compomer Dyract and composite Herculite (SDS, Kerr, U.S.A.) material. Pulp of a treated tooth remained its vitality during control study and pathological changes of pulp and within adjacent periapical tissues were not detected by means of an X-ray photography. After 12 months of observation a positive therapeutic result of pulp vitality preservation in a tooth was achieved.

  6. Dental stem cell therapy with calcium hydroxide in dental pulp capping.

    PubMed

    Ji, Young-Min; Jeon, Soung Hoo; Park, Joo-Young; Chung, Jong-Hoon; Choung, Yun-Hoon; Choung, Pill-Hoon

    2010-06-01

    Calcium hydroxide has been extensively and steadily used for direct pulp capping in modern clinical dentistry. As it was known to have potential to induce hard tissue repair, this chemical has been applied to the exposed dental pulp and the hard tissue is expected to be regenerated above the pulp. During the reparative process of exposed pulp, primary odontoblasts that were lost as a result of extensive damage are replaced with newly differentiated odontoblast-like cells. This process is known to follow the sequential steps of proliferation, migration, and differentiation of progenitor cells. This research will examine the relationship between calcium hydroxide and the recruitment, proliferation, and mineralization of postnatal dental stem cells, obtained from an immature dental tissue of beagle dogs. Immunocytochemical staining and reverse transcriptase-polymerase chain reaction were used to identify the putative stem cell markers. Immunoblot analysis, wound healing assay, cell migration assay, and alizarin red staining were used to evaluate proliferation, migration, and mineralization capacity of the calcium hydroxide-treated stem cells. As an in vivo study, a combination of calcium hydroxide and autologous dental pulp stem cells (DPSCs) was applied for the treatment of intentionally created tooth defects on the premolars and the molars in beagle dogs to observe dentin regeneration. Ex vivo expanded DPSCs and periodontal ligament stem cells expressed STRO-1 and CD146, the mesenchymal stem cell markers. It was evident that calcium hydroxide increased recruitment, migration, proliferation, and mineralization of the DPSCs and periodontal ligament stem cells. Such results are valuable for future availability of DPSCs, which are recently focused as the stem cell reservoir for regeneration of dentin upon tooth injury, as well as for elucidation of the role of calcium hydroxide in pulp capping therapy.

  7. Alkaliphilic endoxylanase from lignocellulolytic microbial consortium metagenome for biobleaching of eucalyptus pulp.

    PubMed

    Weerachavangkul, Chawannapak; Laothanachareon, Thanaporn; Boonyapakron, Katewadee; Wongwilaiwalin, Sarunyou; Nimchua, Thidarat; Eurwilaichitr, Lily; Pootanakit, Kusol; Igarashi, Yasuo; Champreda, Verawat

    2012-12-01

    Enzymatic pre-bleaching by modification of pulp fibers with xylanases is an attractive approach to reduce the consumption of toxic bleaching chemicals in the paper industry. In this study, an alkaliphilic endoxylanase gene was isolated from metagenomic DNA of a structurally stable thermophilic lignocellulose-degrading microbial consortium using amplification with conserved glycosyl hydrolase family 10 primers and subsequent genome walking. The full-length xylanase showed 78% sequence identity to an endo-beta-1,4-xylanase of Clostridium phytofermentans and was expressed in a mature form with an N-terminal His6 tag fusion in Escherichia coli. The recombinant xylanase Xyn3F was thermotolerant and alkaliphilic, working optimally at 65-70 degrees C with an optimal pH at 9- 10 and retaining >80% activity at pH 9, 60 degrees C for 1 h. Xyn3F showed a Vmax of 2,327 IU/mg and Km of 3.5 mg/ml on birchwood xylan. Pre-bleaching of industrial eucalyptus pulp with no prior pH adjustment (pH 9) using Xyn3F at 50 IU/g dried pulp led to 4.5-5.1% increase in final pulp brightness and 90.4-102.4% increase in whiteness after a single-step hypochlorite bleaching over the untreated pulp, which allowed at least 20% decrease in hypochlorite consumption to achieve the same final bleaching indices. The alkaliphilic xylanase is promising for application in an environmentally friendly bleaching step of kraft and soda pulps with no requirement for pH adjustment, leading to improved economic feasibility of the process.

  8. Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity

    SciTech Connect

    Stuart E. Strand

    2001-12-06

    The chemicals used in pulping of wood by the kraft process are recycled in the mill in the recovery furnace, which oxidizes organics while simultaneously reducing sulfate to sulfide. The recovery furnace is central to the economical operation of kraft pulp mills, but it also causes problems. The total pulp production of many mills is limited by the recovery furnace capacity, which cannot easily be increased. The furnace is one of the largest sources of air pollution (as reduced sulfur compounds) in the kraft pulp mill.

  9. Paper pulp from sugar mill bagasse

    SciTech Connect

    Krueger, H.; Berndt, W.; Schwartzkopff, U.; Reitter, F.J.; Hoepner, T.; Muehlig, H.J.

    1981-04-07

    This is a continuation-in-part of US Serial No. 884,513, abandoned. Neutral sulfite semichemical (NSSC) cooking of depithed bagasse gave pulp with improved physicomechanical properties for use in the production of newsprint paper. Thus, the NSSC cooking at 170-175/sup 0/ gave pulp in 70-75% yield. The NSSC pulp as above was bleached with alkali H/sub 2/O/sub 2/ at 50-70/sup 0/ to give a product with breaking load 8.7 kg, tensile 3.9%, breaking length 7.13 km, absolute tearing strength 135 cmg/cm, absolute bursting strength 3.8 kg/sq. cm and Elrepho brightness 61.

  10. Treatment of crown fractures with pulp exposure.

    PubMed

    de Blanco, L P

    1996-11-01

    Thirty permanent incisors with vital pulps and complicated crown fractures were treated by a partial pulpotomy (Cvek technique). This consisted of amputation of 1 to 2 mm of the exposed pulp, placement of calcium hydroxide powder, and a temporary restoration. Clinical and radiographic assessment of the hard tissue barrier was done after 3 months and again after 1 to 8 years. The treatment was successful in all incisors. No differences were found in stage of root development, size of exposure, and length of time exposed. In conclusion, the partial pulpotomy technique is a successful and permanent treatment for crown fractures with pulp exposure regardless of the size of exposure, the maturity of the root, or the interval between accident and dental treatment.

  11. Biocompatibility of a new pulp capping cement

    PubMed Central

    Poggio, Claudio; Ceci, Matteo; Beltrami, Riccardo; Dagna, Alberto; Colombo, Marco; Chiesa, Marco

    2014-01-01

    Summary Aim The aim of the present study was to evaluate the biocompatibility of a new pulp capping material (Biodentine, Septodont) compared with reference pulp capping materials: Dycal (Dentsply), ProRoot MTA (Dentsply) and MTA-Angelus (Angelus) by using murine odontoblast cell line and Alamar blue and MTT cytotoxicity tests. Methods The citocompatibility of murine odontoblasts cells (MDPC-23) were evaluated at different times using a 24 Transwell culture plate by Alamar blue test and MTT assay. Results The results were significantly different among the pulp capping materials tested. Biocompatibility was significant different among materials with different composition. Conclusions Biodentine and MTA-based products show lower cytotoxicity varying from calcium hydroxide-based material which present higher citotoxicity. PMID:25002921

  12. 21 CFR 176.260 - Pulp from reclaimed fiber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pulp from reclaimed fiber. 176.260 Section 176.260... for Use Only as Components of Paper and Paperboard § 176.260 Pulp from reclaimed fiber. (a) Pulp from reclaimed fiber may be safely used as a component of articles used in producing, manufacturing,...

  13. 21 CFR 176.260 - Pulp from reclaimed fiber.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pulp from reclaimed fiber. 176.260 Section 176.260... for Use Only as Components of Paper and Paperboard § 176.260 Pulp from reclaimed fiber. (a) Pulp from reclaimed fiber may be safely used as a component of articles used in producing, manufacturing,...

  14. Properties of kenaf from various cultivars, growth and pulping conditions

    Treesearch

    James S. Han; Ernest S. Miyashita; Sara J. Spielvogel

    1999-01-01

    The physical properties of kenaf offer potential as an alternative raw material for the manufacture of paper. Investigations to date have not determined whether core and fiber should be pulped together or separately. Kenaf bast and core fibers of different cultivars were pulped under various kraft pulping conditions and physical properties: density, Canadian Standard...

  15. Ranking mechanical pulps for their potential to photoyellow

    Treesearch

    Umesh P. Agarwal

    2000-01-01

    Recently found experimental evidence has provided strong support for an alternative photoyellowing mechanism that suggests that pulp- photoyellowing occurs due to direct photooxidation of hydroquinones (present in mechanical pulps) top-quinones. Because hydroquinones were found to be present in pulps, it may be possible to quantify them. Quantification of mechanical-...

  16. The pulp. A big issue about a little tissue.

    PubMed

    Feiglin, B

    1978-02-01

    Difficulties in correlating pulp symptomology with available histopathological and biochemical data have hampered understanding of pulp reaction to stimuli. Some of the less well known biochemical cell and tissue regulatory systems are appraised. Pathways whereby such systems could be implicated in pulp function are suggested.

  17. 21 CFR 176.260 - Pulp from reclaimed fiber.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pulp from reclaimed fiber. 176.260 Section 176.260... for Use Only as Components of Paper and Paperboard § 176.260 Pulp from reclaimed fiber. (a) Pulp from reclaimed fiber may be safely used as a component of articles used in producing, manufacturing, packing...

  18. 21 CFR 176.260 - Pulp from reclaimed fiber.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pulp from reclaimed fiber. 176.260 Section 176.260... for Use Only as Components of Paper and Paperboard § 176.260 Pulp from reclaimed fiber. (a) Pulp from reclaimed fiber may be safely used as a component of articles used in producing, manufacturing, packing...

  19. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrode gel for pulp testers. 872.1730 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1730 Electrode gel for pulp testers. (a) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a tooth...

  20. Frequently asked questions in direct pulp capping of permanent teeth.

    PubMed

    Mouawad, Stéphanie; Artine, Simon; Hajjar, Pétra; McConnell, Robert; Fahd, Jean-Claude; Sabbagh, Joseph

    2014-05-01

    Direct pulp capping is a proven method of preserving tooth vitality of a mature permanent tooth in cases of pulp exposures. The indications for this treatment, treatment modalities and materials are discussed in this paper. This paper answers many of the frequently asked questions by general practitioners, dental students and specialists about direct pulp capping.

  1. Integrated hydrolyzation and fermentation of sugar beet pulp to bioethanol.

    PubMed

    Rezić, Tonči; Oros, Damir; Marković, Iva; Kracher, Daniel; Ludwig, Roland; Santek, Božidar

    2013-09-28

    Sugar beet pulp is an abundant industrial waste material that holds a great potential for bioethanol production owing to its high content of cellulose, hemicelluloses, and pectin. Its structural and chemical robustness limits the yield of fermentable sugars obtained by hydrolyzation and represents the main bottleneck for bioethanol production. Physical (ultrasound and thermal) pretreatment methods were tested and combined with enzymatic hydrolysis by cellulase and pectinase to evaluate the most efficient strategy. The optimized hydrolysis process was combined with a fermentation step using a Saccharomyces cerevisiae strain for ethanol production in a single-tank bioreactor. Optimal sugar beet pulp conversion was achieved at a concentration of 60 g/l (39% of dry weight) and a bioreactor stirrer speed of 960 rpm. The maximum ethanol yield was 0.1 g ethanol/g of dry weight (0.25 g ethanol/g total sugar content), the efficiency of ethanol production was 49%, and the productivity of the bioprocess was 0.29 g/l·h, respectively.

  2. Production and characterization of chars from cherry pulp via pyrolysis.

    PubMed

    Pehlivan, E; Özbay, N; Yargıç, A S; Şahin, R Z

    2017-12-01

    Pyrolysis is an eco-friendly process to achieve valuable products like bio-oil, char and gases. In the last decades, biochar production from pyrolysis of a wide variety of industrial and agricultural wastes become popular, which can be utilized as adsorbent instead of the expensive activated carbons. In this study, cherry pulp was pyrolyzed in a fixed bed tubular reactor at five different temperatures (400, 500,550, 600 and 700 °C) and three different heating rates (10, 100 and 200 °C/min) to obtain biochar. Proximate, ultimate, nitrogen adsorption/desorption isotherms, scanning electron microscopy, thermogravimetric analysis, x-ray fluorescence, x-ray diffraction, and Fourier transform infrared spectroscopy were performed on cherry pulp and its chars to examine the chemical alterations after the pyrolysis process. Biochar yields were decreased with increasing pyrolysis temperature and heating rate, based on experimental results. Porous biochars are carbon rich and includes high potassium content. The aromaticity of biochars increased and O/C mass ratio reduced with an increase in the pyrolysis temperature as a result of the development of compact aromatic structure in char. Pyrolysis provides a promising conversion procedure for the production of high energy density char which has promising applications in existing coal-fired boilers without any upgrading. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Pyrolysis of poppy capsule pulp for bio-oil production.

    PubMed

    Hopa, Derya Yeşim; Yılmaz, Nazan; Alagöz, Oğuzhan; Dilek, Meltem; Helvacı, Ahmet; Durupınar, Ümit

    2016-12-01

    The feasibility of biofuel production via the pyrolysis of poppy capsule pulp, the main waste product of Afyon Alkoloid Factory, was investigated. The poppy capsule pulp was shown to have a high volatile matter content (ca. 76%). Pyrolysis experiments were carried out in the temperature range 400-550°C (heating rate 18°C min(-1) and holding time 20 min) under a nitrogen atmosphere. The chemical components of the bio-oil were characterized by Fourier transform infrared spectrometry and gas chromatography-mass spectrometry. The effects of pyrolysis temperature on the production efficiency and the calorific value of the bio-oil were investigated. The maximum bio-oil yield and its calorific value at 500°C were 23.6% and 31.6 MJ kg(-1), respectively. The latter value is close to that of many petroleum fractions. This high-energy bio-oil is therefore a clean fuel precursor and can be upgraded into higher quality fuels.

  4. Methods for Facilitating Microbial Growth on Pulp Mill Waste Streams and Characterization of the Biodegradation Potential of Cultured Microbes

    PubMed Central

    Mathews, Stephanie L.; Ayoub, Ali S.; Pawlak, Joel; Grunden, Amy M.

    2013-01-01

    The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor. PMID:24378616

  5. Effects of dates pulp extract and palm sap (Phoenix dactylifera L.) on gastrointestinal transit activity in healthy rats.

    PubMed

    Souli, Abdellaziz; Sebai, Hichem; Rtibi, Kaïs; Chehimi, Latifa; Sakly, Mohsen; Amri, Mohamed; El-Benna, Jamel

    2014-07-01

    The current study was performed to measure the chemical composition and the effects of dates pulp extract and palm sap on gastrointestinal transit (GIT) activity in healthy adult rats. In this respect, male Wistar rats fasted for 24 hours were used and received per orally (p.o.) sodium chloride (NaCl) (0,9%) (control group) or various doses of dates pulp extract (150 and 300 mg/kg, body weight [b.w.]) and palm sap (0.4 and 4 mL/kg, b.w.). Two other groups of rats (batch tests) received, respectively, clonidine (an alpha-2 adrenergic agonist, 1 mg/kg, b.w.) and yohimbine (an alpha-2 adrenergic antagonist, 2mg/kg, b.w.). Chemical analysis showed that the dates pulp extract is more rich in sugars and minerals, especially potassium and sucrose, as compared with palm sap composition. On the other hand, in vivo study showed that the aqueous dates pulp extract significantly, and dose dependently, increased the GIT activity while the palm sap slightly increased it. Moreover, a converse effect has been observed using clonidine (decreased 68%) and yohimbine (increased 33%) on the GIT activity. These findings suggest that dates pulp extract and palm sap have a stimulating effect on GIT activity in rats and confirm their use in traditional Tunisian medicine for the treatment of constipation.

  6. Methods for facilitating microbial growth on pulp mill waste streams and characterization of the biodegradation potential of cultured microbes.

    PubMed

    Mathews, Stephanie L; Ayoub, Ali S; Pawlak, Joel; Grunden, Amy M

    2013-12-12

    The kraft process is applied to wood chips for separation of lignin from the polysaccharides within lignocellulose for pulp that will produce a high quality paper. Black liquor is a pulping waste generated by the kraft process that has potential for downstream bioconversion. However, the recalcitrant nature of the lignocellulose resources, its chemical derivatives that constitute the majority of available organic carbon within black liquor, and its basic pH present challenges to microbial biodegradation of this waste material. Methods for the collection and modification of black liquor for microbial growth are aimed at utilization of this pulp waste to convert the lignin, organic acids, and polysaccharide degradation byproducts into valuable chemicals. The lignocellulose extraction techniques presented provide a reproducible method for preparation of lignocellulose growth substrates for understanding metabolic capacities of cultured microorganisms. Use of gas chromatography-mass spectrometry enables the identification and quantification of the fermentation products resulting from the growth of microorganisms on pulping waste. These methods when used together can facilitate the determination of the metabolic activity of microorganisms with potential to produce fermentation products that would provide greater value to the pulping system and reduce effluent waste, thereby increasing potential paper milling profits and offering additional uses for black liquor.

  7. Effects of Dates Pulp Extract and Palm Sap (Phoenix dactylifera L.) on Gastrointestinal Transit Activity in Healthy Rats

    PubMed Central

    Souli, Abdellaziz; Rtibi, Kaïs; Chehimi, Latifa; Sakly, Mohsen; Amri, Mohamed; El-Benna, Jamel

    2014-01-01

    Abstract The current study was performed to measure the chemical composition and the effects of dates pulp extract and palm sap on gastrointestinal transit (GIT) activity in healthy adult rats. In this respect, male Wistar rats fasted for 24 hours were used and received per orally (p.o.) sodium chloride (NaCl) (0,9%) (control group) or various doses of dates pulp extract (150 and 300 mg/kg, body weight [b.w.]) and palm sap (0.4 and 4 mL/kg, b.w.). Two other groups of rats (batch tests) received, respectively, clonidine (an alpha-2 adrenergic agonist, 1 mg/kg, b.w.) and yohimbine (an alpha-2 adrenergic antagonist, 2mg/kg, b.w.). Chemical analysis showed that the dates pulp extract is more rich in sugars and minerals, especially potassium and sucrose, as compared with palm sap composition. On the other hand, in vivo study showed that the aqueous dates pulp extract significantly, and dose dependently, increased the GIT activity while the palm sap slightly increased it. Moreover, a converse effect has been observed using clonidine (decreased 68%) and yohimbine (increased 33%) on the GIT activity. These findings suggest that dates pulp extract and palm sap have a stimulating effect on GIT activity in rats and confirm their use in traditional Tunisian medicine for the treatment of constipation. PMID:24611963

  8. Effects of Soda-Anthraquinone Pulping Variables on the Durian Rind Pulp and Paper Characteristics: A Preliminary Test

    NASA Astrophysics Data System (ADS)

    Rizal Masrol, Shaiful; Irwan Ibrahim, Mohd Halim; Adnan, Sharmiza; Rahmad Talib, Mohd; Sian, Lau Lee

    2017-08-01

    Good combination of pulping variables is required to obtain the quality pulp and paper characteristics. Thus, in this preliminary work, naturally dried durian rind were pulped under Soda-Anthraquinone (Soda-AQ) pulping process with 18% to 22% alkali charge, 0% to 0.1% Anthraquinone (AQ) charge, 90 minutes to 150 minutes of cooking time and 150°C to 170°C to investigate the effect of pulping variables on the characteristics of the pulp and paper. Pulping condition with 0% of AQ charge was also conducted for comparison. Results indicated that the best screen yield percentage, reject yield percentage, freeness, drainage time, tear index, number of folds and optical properties were shown by the pulp produced with combination of the highest active alkali (22%), AQ charge (0.1%), cooking time (150 minutes) and cooking temperature (170°C) except apparent density, tensile index and burst index. This preliminary result shows that the optimum quality of durian rind pulp as a potential papermaking raw material pulp could be produced by selecting the good combination of pulping variables which influences the pulp and paper characteristics.

  9. Selective Enrichment of a Methanol-Utilizing Consortium Using Pulp and Paper Mill Waste Streams

    NASA Astrophysics Data System (ADS)

    Mockos, Gregory R.; Smith, William A.; Loge, Frank J.; Thompson, David N.

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Wasteactivated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/ decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  10. Selective enrichment of a methanol-utilizing consortium using pulp and paper mill waste streams.

    PubMed

    Mockos, Gregory R; Smith, William A; Loge, Frank J; Thompson, David N

    2008-03-01

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste-activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25 degrees C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  11. Selective enrichment of a methanol-utilizing consortium using pulp & paper mill waste streams

    SciTech Connect

    Gregory R. Mockos; William A. Smith; Frank J. Loge; David N. Thompson

    2007-04-01

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater . Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of four days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24 hour feed/decant cycles ranged from 79 to 89 %, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen limited conditions. This indicates that selectively-enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  12. CYTOTOXICITY AND BIOCOMPATIBILITY OF DIRECT AND INDIRECT PULP CAPPING MATERIALS

    PubMed Central

    Modena, Karin Cristina da Silva; Casas-Apayco, Leslie Caroll; Atta, Maria Teresa; Costa, Carlos Alberto de Souza; Hebling, Josimeri; Sipert, Carla Renata; Navarro, Maria Fidela de Lima; Santos, Carlos Ferreira

    2009-01-01

    There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH), adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH. PMID:20027424

  13. Method for rapidly determining a pulp kappa number using spectrophotometry

    SciTech Connect

    Chai, Xin-Sheng; Zhu, Jun Yong

    2002-01-01

    A system and method for rapidly determining the pulp kappa number through direct measurement of the potassium permanganate concentration in a pulp-permanganate solution using spectrophotometry. Specifically, the present invention uses strong acidification to carry out the pulp-permanganate oxidation reaction in the pulp-permanganate solution to prevent the precipitation of manganese dioxide (MnO.sub.2). Consequently, spectral interference from the precipitated MnO.sub.2 is eliminated and the oxidation reaction becomes dominant. The spectral intensity of the oxidation reaction is then analyzed to determine the pulp kappa number.

  14. Anaerobic digestion of pulp and paper mill wastewater and sludge.

    PubMed

    Meyer, Torsten; Edwards, Elizabeth A

    2014-11-15

    Pulp and paper mills generate large amounts of waste organic matter that may be converted to renewable energy in form of methane. The anaerobic treatment of mill wastewater is widely accepted however, usually only applied to few selected streams. Chemical oxygen demand (COD) removal rates in full-scale reactors range between 30 and 90%, and methane yields are 0.30-0.40 m(3) kg(-1) COD removed. Highest COD removal rates are achieved with condensate streams from chemical pulping (75-90%) and paper mill effluents (60-80%). Numerous laboratory and pilot-scale studies have shown that, contrary to common perception, most other mill effluents are also to some extent anaerobically treatable. Even for difficult-to-digest streams such as bleaching effluents COD removal rates range between 15 and 90%, depending on the extent of dilution prior to anaerobic treatment, and the applied experimental setting. Co-digestion of different streams containing diverse substrate can level out and diminish toxicity, and may lead to a more robust microbial community. Furthermore, the microbial population has the ability to become acclimated and adapted to adverse conditions. Stress situations such as toxic shock loads or temporary organic overloading may be tolerated by an adapted community, whereas they could lead to process disturbance with an un-adapted community. Therefore, anaerobic treatment of wastewater containing elevated levels of inhibitors or toxicants should be initiated by an acclimation/adaptation period that can last between a few weeks and several months. In order to gain more insight into the underlying processes of microbial acclimation/adaptation and co-digestion, future research should focus on the relationship between wastewater composition, reactor operation and microbial community dynamics. The potential for engineering and managing the microbial resource is still largely untapped. Unlike in wastewater treatment, anaerobic digestion of mill biosludge (waste activated

  15. Refractory organic pollutants and toxicity in pulp and paper mill wastewaters.

    PubMed

    Lindholm-Lehto, Petra C; Knuutinen, Juha S; Ahkola, Heidi S J; Herve, Sirpa H

    2015-05-01

    This review describes medium and high molecular weight organic material found in wastewaters from pulp and paper industry. The aim is to review the versatile pollutants and the analysis methods for their determination. Among other pollutants, biocides, extractives, and lignin-derived compounds are major contributors to harmful effects, such as toxicity, of industrial wastewaters. Toxicity of wastewaters from pulp and paper mills is briefly evaluated including the methods for toxicity analyses. Traditionally, wastewater purification includes mechanical treatment followed by chemical and/or biological treatment processes. A variety of methods are available for the purification of industrial wastewaters, including aerobic and anaerobic processes. However, some fractions of organic material, such as lignin and its derivatives, are difficult to degrade. Therefore, novel chemical methods, including electrochemical and oxidation processes, have been developed for separate use or in combination with biological treatment processes.

  16. Clastogenic activity of seven endodontic medications used in dental practice in human dental pulp cells.

    PubMed

    Someya, Hitomi; Higo, Yukari; Ohno, Maki; Tsutsui, Takeo W; Tsutsui, Takeki

    2008-01-31

    Numerous and varied chemical agents are used for endodontic treatments in dental practice. Endodontic medications are administered directly to the teeth in relatively high concentrations and chemical agents applied to enamel or dentin can penetrate the dental pulp tissue and circulate through the body in the bloodstream. In the present study, to assess safety regarding mutagenicity, we investigated the ability of seven endodontic medications to induce chromosome aberrations in human dental pulp cells. Chromosome aberrations were induced in cells treated with each of six endodontic medications, eugenol, guaiacol, modified phenol, phenol, thymol, and zinc oxide. The other endodontic medication, zinc chloride, failed to induce chromosome aberrations in the presence or absence of exogenous metabolic activation. The percentages of cells with polyploid or endoreduplication were not enhanced by any of the endodontic medications tested. Our results indicate that the endodontic medications that exhibited a positive response are potentially mutagenic to human cells.

  17. Integration of the Mini-Sulfide Sulfite Anthraquinone (MSS-AQ) Pulping Process and Black Liquor Gasification in a Pulp Mill

    SciTech Connect

    Hasan Jameel, North Carolina State University; Adrianna Kirkman, North Carolina State University; Ravi Chandran,Thermochem Recovery International Brian Turk Research Triangle Institute; Brian Green, Research Triangle Institute

    2010-01-27

    As many of the recovery boilers and other pieces of large capital equipment of U.S. pulp mills are nearing the end of their useful life, the pulp and paper industry will soon need to make long-term investments in new technologies. The ability to install integrated, complete systems that are highly efficient will impact the industry’s energy use for decades to come. Developing a process for these new systems is key to the adoption of state-of-the-art technologies in the Forest Products industry. This project defined an integrated process model that combines mini-sulfide sulfite anthraquinone (MSS-AQ) pulping and black liquor gasification with a proprietary desulfurization process developed by the Research Triangle Institute. Black liquor gasification is an emerging technology that enables the use of MSS-AQ pulping, which results in higher yield, lower bleaching cost, lower sulfur emissions, and the elimination of causticization requirements. The recently developed gas cleanup/absorber technology can clean the product gas to a state suitable for use in a gas turbine and also regenerate the pulping chemicals needed to for the MSS-AQ pulping process. The combination of three advanced technologies into an integrated design will enable the pulping industry to achieve a new level of efficiency, environmental performance, and cost savings. Because the three technologies are complimentary, their adoption as a streamlined package will ensure their ability to deliver maximum energy and cost savings benefits. The process models developed by this project will enable the successful integration of new technologies into the next generation of chemical pulping mills. When compared to the Kraft reference pulp, the MSS-AQ procedures produced pulps with a 10-15 % yield benefit and the ISO brightness was 1.5-2 times greater. The pulp refined little easier and had a slightly lower apparent sheet density (In both the cases). At similar levels of tear index the MSS-AQ pulps also

  18. Combination of steam explosion and laccase-mediator treatments prior to Eucalyptus globulus kraft pulping.

    PubMed

    Martín-Sampedro, R; Eugenio, M E; Carbajo, J M; Villar, J C

    2011-07-01

    The effect of a pretreatment consisting of steam explosion (SE) followed by a laccase mediator system (LMS) stage on Eucalyptus globulus kraft pulping has been evaluated and compared with fungal pretreatments. Pretreatment with SE and LMS was more efficient than pretreatments using Pycnoporus sanguineus and Trametes sp. I-62. Steam explosion not only improved the enzyme penetration into the wood chips and shortened the pulping process by 60%, but also extracted around 50% of the hemicelluloses which could be converted into value-added products. The optimal conditions for the LMS treatment were 3h, 3UA/g and 40°C. Compared to SE, the SE/LMS treatment yielded an increase in delignification of 13.9% without affecting pulp properties, provided a similar screened kraft yield, and reduced consumption of chemical reagents Na(2)S and NaOH by 11.5% and 6.3%, respectively. Therefore, SE/LMS is a promising pretreatment for converting the pulp mill into a forest bio-refinery.

  19. The potential in bioethanol production from waste fiber sludges in pulp mill-based biorefineries.

    PubMed

    Sjöde, Anders; Alriksson, Björn; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2007-04-01

    Industrial production of bioethanol from fibers that are unusable for pulp production in pulp mills offers an approach to product diversification and more efficient exploitation of the raw material. In an attempt to utilize fibers flowing to the biological waste treatment, selected fiber sludges from three different pulp mills were collected, chemically analyzed, enzymatically hydrolyzed, and fermented for bioethanol production. Another aim was to produce solid residues with higher heat values than those of the original fiber sludges to gain a better fuel for combustion. The glucan content ranged between 32 and 66% of the dry matter. The lignin content varied considerably (1-25%), as did the content of wood extractives (0.2-5.8%). Hydrolysates obtained using enzymatic hydrolysis were found to be readily fermentable using Saccharomyces cerevisiae. Hydrolysis resulted in improved heat values compared with corresponding untreated fiber sludges. Oligomeric xylan fragments in the solid residue obtained after enzymatic hydrolysis were identified using matrix-assisted laser desorption ionization-time of flight and their potential as a new product of a pulp mill-based biorefinery is discussed.

  20. Analysis of the effect of wash water reduction on bleached pulp characteristics.

    PubMed

    Frigieri, Tânia Cristina; Ventorim, Gustavo; Savi, Antônio Francisco; Favaro, Jaqueline Silveira Comelato

    2015-01-01

    The main objective of this study was to analyse cost reduction by reducing the use of fresh water in the cellulose bleaching process and to make it easier to obtain water in a closed circuit. Eucalyptus oxygen delignified industrial pulp was used. The pulp was bleached 10 times in the D(E+P)DP sequence in the same conditions. Counter current washing was used in the bleaching stages, and each sequence was carried out with different wash factors: 9, 6, 3, and 0 m³ of distilled water/ton of oven dry pulp. The goal was to reach brightness of 92±0.5% ISO. The results showed that there was a chemical oxygen demand (COD) increase and brightness reversion, but the kappa number and viscosity did not change. The apparent colour was increased by increasing COD in the effluent during the cycles and by decreasing the wash water. Up to 3 m³/t of water was tolerable and even recommended to wash pulp. Nine cubic metre per tonne of fresh water is most commonly used in the industry, so water savings make the implementation of the process possible.

  1. Fractionation of sugar beet pulp into pectin, cellulose, and arabinose by arabinases combined with ultrafiltration

    SciTech Connect

    Spangnuolo, M.; Crecchio, C.; Pizzigallo, M.D.R.; Ruggiero, P.

    1999-09-20

    Incubation of beet pulp with two arabinases ({alpha}-L-arabinofuranosidase and endo-arabinase), used singularly or in combination at different units of activity per gram of beet pulp, caused the hydrolysis of arabinasn, which produced a hydrolyzate consisting mainly of arabinose. Pectin and a residue enriched with cellulose were subsequently separated from the incubation mixture. The best enzymatic hydrolysis results were obtained when 100 U/g of beet pulp of each enzyme worked synergistically with yields of 100% arabinose and 91.7% pectin. These yields were higher than those obtained with traditional chemical hydrolysis. The pectin fraction showed a low content of neutral sugar content and the cellulose residue contained only a small amount of pentoses. Semicontinuous hydrolysis with enzyme recycling in an ultrafiltration unit was also carried out to separate arabinose, pectin, and cellulose from beet pulp in 7 cycles of hydrolysis followed by ultrafiltration. The yields of separation were similar to those obtained in batch experiments, with an enzyme consumption reduced by 3.5 times and some significant advantages over batch processes.

  2. Nutritional Content and Antioxidant Properties of Pulp Waste from Daucus carota and Beta vulgaris.

    PubMed

    Shyamala, B N; Jamuna, P

    2010-12-01

    This study reports the chemical composition and antioxidant potential of pulp waste from two vegetables, carrot (Daucus carota) and beetroot (Beta vulgaris). Different in vitro assays used for determining antioxidant potential of extracts of pulp wastes were: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power and total antioxidant activity by phosphomolybdenum method. Total polyphenols, tannins and antioxidative components such as vitamin C, total carotenoids and β-carotene were analysed in the samples. The moisture content of samples ranged from 79 - 84%. The protein content was high in beetroot (13.23 mg/100g) and low in carrot (6.21mg/100g). Total polyphenols were higher in methanol extracts of samples (220-250 mg/100g) compared to ethanol and aqueous extracts. The antioxidant activity determined by the DPPH method exhibited 40% and 78% activity in methanol extracts of carrot and beetroot pulp waste (20 mg) respectively. Overall, the results suggest that carrot and beetroot pulp wastes can be exploited for their nutrients and antioxidant components and used for value addition in food formulations. Hence, these results pave the way for utilisation of bio-wastes from the food industry.

  3. Effect of steam explosion and enzymatic pre-treatments on pulping and bleaching of Hesperaloe funifera.

    PubMed

    Martín-Sampedro, R; Eugenio, M E; Villar, J C

    2012-05-01

    A non-wood raw material with high potential for pulp and paper applications (Hesperaloe funifera) was subjected to a steam explosion pre-treatment, and the subsequent effect of this pretreatment on biopulping and biobleaching was studied. An increase in the delignification rate, bigger than that reported for autohydrolysis and acid hydrolysis pre-treatments, and a reduction in chemical consumption were found during kraft pulping of the exploded samples. However, biopulping with the laccase-mediator system (LMS) did not lead to a reduction in the kappa number in either non-exploded or exploded unbleached pulps. On the other hand, the steam explosion pretreatment boosted the advantages of the LMS pre-treatment (decrease in kappa number and increase in brightness) favored biobleaching, with a 53.1% delignification rate and a final brightness of 67% ISO. Finally, the steam explosion pre-treatment also improved the color properties of the bleached pulp and reduced the hydrogen peroxide consumption by 24.6%.

  4. Histopathology, enzyme activities, and PAH metabolites in English sole collected near coastal pulp mills

    SciTech Connect

    Brand, D.G.

    1995-12-31

    The bottom-feeding flatfish, English sole (Pleuronectes vetulus), is widely distributed along the B.C. Pacific coast and fulfills a majority of the requirements as a sentinel species for environmental effects monitoring programs. Studies involving the use of histopathological, biochemical, and chemical tools with English sole collected near the vicinity of B.C. pulp mills are currently being conducted. Analysis, to date, has revealed idiopathic liver lesions to be strongly dependent on location of capture with a prevalence of 30% preneoplastic and neoplastic lesions found in fish collected near pulp mills. All fish residing near pulp mills show hepatocellular hemosiderosis, an iron storage disorder. The mixed-function oxidizing enzyme, EROD, was found to be induced in fish collected near pulp mills. However, the levels of conjugating enzymes, GST and UDP-GT, were found to be unchanged when compared with reference fish. PAH metabolites, measured as FACs in bile, are also present in English sole collected from the mill sites and the conjugated derivatives are presently being identified by HPLC/ES-MS techniques, The relationships between these observations will be discussed.

  5. The Potential in Bioethanol Production From Waste Fiber Sludges in Pulp Mill-Based Biorefineries

    NASA Astrophysics Data System (ADS)

    Sjöde, Anders; Alriksson, Björn; Jönsson, Leif J.; Nilvebrant, Nils-Olof

    Industrial production of bioethanol from fibers that are unusable for pulp production in pulp mills offers an approach to product diversification and more efficient exploitation of the raw material. In an attempt to utilize fibers flowing to the biological waste treatment, selected fiber sludges from three different pulp mills were collected, chemically analyzed, enzymatically hydrolyzed, and fermented for bioethanol production. Another aim was to produce solid residues with higher heat values than those of the original fiber sludges to gain a better fuel for combustion. The glucan content ranged between 32 and 66% of the dry matter. The lignin content varied considerably (1-25%), as did the content of wood extractives (0.2-5.8%). Hydrolysates obtained using enzymatic hydrolysis were found to be readily fermentable using Saccharomyces cerevisiae. Hydrolysis resulted in improved heat values compared with corresponding untreated fiber sludges. Oligomeric xylan fragments in the solid residue obtained after enzymatic hydrolysis were identified using matrix-assisted laser desorption ionization-time of flight and their potential as a new product of a pulp mill-based biorefinery is discussed.

  6. Evaluation of the dentin-pulp complex after cavity preparation with ultrasonic diamond tip.

    PubMed

    Monti Lima, L; Baffi Diniz, M; Aparecida Seccani Galassi, M; Toledo De Oliveira Ramalho, L; Dos Santos-Pinto, L

    2011-01-01

    The aim of this paper was to compare the dentin-pulp complex response to cavity preparation in human teeth using ultrasonic chemical vapor deposition (CVD) diamond tip and high-speed diamond bur. Class V buccal cavities were randomly prepared in 40 premolars from 14 patients aged 11 to 15 years. The cutting time was recorded and the cavities had the axial walls protected with gutta-percha and were filled with glass ionomer cement. The teeth were extracted at intervals of 0, 5, 10 and 20 days, and were decalcified, sectioned and stained by Hematoxylin & Eosin, Masson's Trichrome and Brown & Brenn techniques. The inflammatory response and cell disorganization were blindly evaluated by two examiners. The remaining dentin thickness (RDT) was measured by a linear scale using computer software. Statistical analysis by one-way ANOVA showed no statistically significant difference (P≤0.05) among the cavities prepared with either type of instrument, with mean RDT of 1132.50 mm. Cutting time and the pulp-dentin complex responses were analyzed statistically by Kruskal-Wallis and Dunn tests (P≤0.05). The ultrasonic CVD diamond tip took 5 times longer to prepare the cavities and there were no typical inflammatory pulp responses in cavities prepared with either type of cutting instrument, only mild to moderate cell disorganization was present. Even taking longer to cut the dental substrate, the ultrasonic CVD diamond tip produced similar pulp response compared to the conventional high-speed diamond bur.

  7. Fourier transform infrared spectroscopy (FTIR) analysis of paddy straw pulp treated using deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Lun, Lim Wei; Gunny, Ahmad Anas Nagoor; Kasim, Farizul Hafiz; Arbain, Dachyar

    2017-04-01

    This study focus on Fourier Transform Infrared Spectroscopy (FTIR) analysis of paddy straw pulp treated using deep eutectic solvent (DES). DES was synthesized using potassium carbonate and glycerol at different molar ratio under normal atmospheric pressure. Pretreatment of lignocellulosic biomass was carried out at temperature of 120°C for 60 minutes under mass ratio of paddy straw to DES 1:9. The chemical structures of the untreated paddy straw and paddy straw pulp treated with different molar ratio of DES were analyzed using FTIR. The characterization result from FT-IR spectra indicated that the potassium carbonate-glycerol DES deconstructed the structures of paddy straw by removing lignin and hemicellulose during the pulping process. The peak intensity that occurs at region between 900 cm-1 and 1500 cm-1 shows that the presence of elevated level of cellulose after lignocellulosic pulping. From FT-IR analysis, DES could not remove the functional group of lignin and hemicellulose completely but yet expose the structure of cellulose.

  8. Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells

    PubMed Central

    Viña-Almunia, Jose; Borras, Consuelo; Gambini, Juan; El Alamy, Marya; Viña, Jose

    2016-01-01

    Background Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. Material and Methods One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. Results Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ml of thermolysine for 40 minutes and sonicating the culture for one minute. Conclusions Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agents. Key words:Dental pulp stem cells, mesenchymal stem cells, isolation method. PMID:26946201

  9. Potassium hydroxide pulping of rice straw in biorefinery initiatives.

    PubMed

    Jahan, M Sarwar; Haris, Fahmida; Rahman, M Mostafizur; Samaddar, Purabi Rani; Sutradhar, Shrikanta

    2016-11-01

    Rice straw is supposed to be one of the most important lignocellulosic raw materials for pulp mill in Asian countries. The major problem in rice straw pulping is silica. The present research is focused on the separation of silica from the black liquor of rice straw pulping by potassium hydroxide (KOH) and pulp evaluation. Optimum KOH pulping conditions of rice straw were alkali charge 12% as NaOH, cooking temperature 150°C for 2h and material to liquor ratio, 1:6. At this condition pulp yield was 42.4% with kappa number 10.3. KOH pulp bleached to 85% brightness by D0EpD1 bleaching sequences with ClO2 consumption of 25kg/ton of pulp. Silica and lignin were separated from the black liquor of KOH pulping. The amount of recovered silica, lignin and hemicelluloses were 10.4%, 8.4% and 13.0%. The papermaking properties of KOH pulp from rice straw were slightly better than those of corresponding NaOH pulp.

  10. Pulp stem cells: implication in reparative dentin formation.

    PubMed

    Dimitrova-Nakov, Sasha; Baudry, Anne; Harichane, Yassine; Kellermann, Odile; Goldberg, Michel

    2014-04-01

    Many dental pulp stem cells are neural crest derivatives essential for lifelong maintenance of tooth functions and homeostasis as well as tooth repair. These cells may be directly implicated in the healing process or indirectly involved in cell-to-cell diffusion of paracrine messages to resident (pulpoblasts) or nonresident cells (migrating mesenchymal cells). The identity of the pulp progenitors and the mechanisms sustaining their regenerative capacity remain largely unknown. Taking advantage of the A4 cell line, a multipotent stem cell derived from the molar pulp of mouse embryo, we investigated the capacity of these pulp-derived precursors to induce in vivo the formation of a reparative dentin-like structure upon implantation within the pulp of a rodent incisor or a first maxillary molar after surgical exposure. One month after the pulp injury alone, a nonmineralized fibrous matrix filled the mesial part of the coronal pulp chamber. Upon A4 cell implantation, a mineralized osteodentin was formed in the implantation site without affecting the structure and vitality of the residual pulp in the central and distal parts of the pulp chamber. These results show that dental pulp stem cells can induce the formation of reparative dentin and therefore constitute a useful tool for pulp therapies. Finally, reparative dentin was also built up when A4 progenitors were performed by alginate beads, suggesting that alginate is a suitable carrier for cell implantation in teeth.

  11. Pulp and dentin tissue engineering and regeneration: current progress

    PubMed Central

    Huang, George TJ

    2009-01-01

    Dental pulp tissue is vulnerable to infection. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial rubber-like material is employed to treat the infection – commonly known as root-canal therapy. Regeneration of pulp tissue has been difficult as the tissue is encased in dentin without collateral blood supply except from the root apical end. However, with the advent of the concept of modern tissue engineering and the discovery of dental stem cells, regeneration of pulp and dentin has been tested. This article will review the early attempts to regenerate pulp tissue and the current endeavor of pulp and dentin tissue engineering, and regeneration. The prospective outcome of the current advancement in this line of research will be discussed. PMID:19761395

  12. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  13. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  14. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  15. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  16. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... food packaging containers. (c) The ingredient is used in paper and paperboard made by conventional... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT...

  17. Optimizing lodgepole pine submerchantable log thermomechanical pulp

    Treesearch

    Gary C. Myers

    2004-01-01

    To restore and maintain ecosystem health and function in the western interior of the United States, many small-diameter stems need to be removed from densely stocked stands. These stems are considered nonusable or underutilized (good, economical uses need to be developed). As of now, the most logical use for the small-diameter resource is pulp. In this study,...

  18. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... battery powered device intended to evaluate the pulpal vitality of teeth by employing high frequency...

  19. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... battery powered device intended to evaluate the pulpal vitality of teeth by employing high frequency...

  20. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... battery powered device intended to evaluate the pulpal vitality of teeth by employing high frequency...

  1. 21 CFR 872.1720 - Pulp tester.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pulp tester. 872.1720 Section 872.1720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... battery powered device intended to evaluate the pulpal vitality of teeth by employing high frequency...

  2. [New cellulases efficiently hydrolyzing lignocellulose pulp].

    PubMed

    Skomarovskiĭ, A A; Markov, A V; Gusakov, A V; Kondrat'eva, E G; Okunev, O N; Bekkerevich, A O; Matys, V Iu; Sinitsyn, A P

    2006-01-01

    Commercial and pilot enzyme preparations from fungi of the genera Penicillium and Trichoderma have been compared with regard to their action on conifer wood pretreated with acidified aqueous ethanol (organosolve). In most experiments, enzymes from the genus Penicillium allowed higher yields of reducing sugars and glucose than those from Trichoderma. High beta-glucosidase activity is essential for deep pulp hydrolysis.

  3. Archaea prevalence in inflamed pulp tissues

    PubMed Central

    Efenberger, Magdalena; Agier, Justyna; Pawłowska, Elżbieta

    2015-01-01

    Archaea have been detected in several ecological niches of the human body such as the large intestine, skin, vagina as well as the oral cavity. At present, archaea are recognized as nonpathogenic microorganisms. However, some data indicate that they may be involved in the etiopathogenesis of several diseases, including intestinal diseases as well as oral diseases: periodontitis, peri-implantitis and endodontitis. In this study, on the basis of 16S rRNA gene sequence analysis, we examined whether archaea might be present in inflamed pulp tissues and contribute to the development of endodontic infection. In comparison, we also determined selected bacterial species associated with endodontitis. We detected archaea in 85% of infected endodontic samples. In addition, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola were present in inflamed pulp tissue samples and Treponema denticola occurred with the highest frequency (70%). Further analysis revealed the presence of methanogenic archaea in analyzed samples. Direct sequencing of archaeal 16S rRNA gene PCR products indicated the occurrence of methanogenic archaea in inflamed pulp tissues; phylogenetically most similar were Methanobrevibacter oralis and Methanobrevibacter smithii. Therefore, our results show that methanogenic archaea are present in inflamed pulp tissues and may participate in the development of endodontic infection. PMID:26557034

  4. Enzymatic approaches in paper industry for pulp refining and biofilm control.

    PubMed

    Torres, C E; Negro, C; Fuente, E; Blanco, A

    2012-10-01

    The use of enzymes has a high potential in the pulp and paper industry to improve the economics of the paper production process and to achieve, at the same time, a reduced environmental impact. Specific enzymes contribute to reduce the amount of chemicals and energy required for the modification of fibers and helps to prevent the formation or development of biofilms. This review is aimed at presenting the latest progresses made in the application of enzymes as refining aids and biofilm control agents.

  5. Pulp and paper plant wastes valorisation in bituminous mixes.

    PubMed

    Modolo, R; Benta, A; Ferreira, V M; Machado, L M

    2010-04-01

    Nowadays, the increasing amount of wastes is a concerning reality and the environmental aspects has become a major priority. Following this worry, the purpose of this experimental study was to investigate the possibility of using pulp and paper inorganic wastes, named dregs and grits, in bituminous mixtures as aggregate replacement to reduce environmental effects of these wastes disposal. First, the wastes were chemically and physically characterized and also tested primarily taking into account the requirements for aggregates in bituminous mixtures. Then, formulations were prepared replacing aggregates with wastes in different amounts. The mechanical properties of these mixtures containing wastes were compared with reference samples based on standard methods. According to the results it was possible to verify that grits had a good performance and it might be directly tested industrially as an aggregate in road construction. On the other hand, dregs need to be treated before incorporation to guarantee stable mixes in terms of water sensitivity. Copyright 2009 Elsevier Ltd. All rights reserved.

  6. Adsorption of hexavalent chromium onto sisal pulp/polypyrrole composites

    NASA Astrophysics Data System (ADS)

    Tan, Y. Y.; Wei, C.; Gong, Y. Y.; Du, L. L.

    2017-02-01

    Sisal pulp/polypyrrole composites(SP/PPy) utilized for the removal of hexavalent chromium [Cr(VI)] from wastewater, were prepared via in-situ chemical oxidation polymerization approach. The structure and morphology of the SP/PPy were analyzed by polarizing optical microscopy (POM), field-emission scanning electron microscopy (SEM)), Energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), the results indicated SP could be efficient dispersion of PPy. The hexavalent chromium adsorption results indicate adsorption capacity of the SP/PPy were dependent on the initial pH, with an optimum pH of 2.0. The sorption kinetic data fitted well to the pseudo-second order model and isotherm data fitted well to the Langmuir isotherm model. The maximum adsorption capacity determined from the Langmuir isotherm is 336.70 mg/g at 25° C.

  7. Alkaline polyol pulping and enzymatic hydrolysis of softwood: effect of pulping severity and pulp properties on cellulase activity and overall sugar yield.

    PubMed

    Hundt, Martin; Schnitzlein, Klaus; Schnitzlein, Michael G

    2013-04-01

    The saccharification of softwood using alkaline polyol pulping (AlkaPolP) and enzymatic hydrolysis was investigated. It will be demonstrated that the AlkaPolP process yields high quality pulps which can easily be hydrolyzed by cellulases. Temperature (180-230°C) and duration (15-60 min) of the alkaline glycerol pulping, expressed as pulping severity R0, were varied to find optimum reaction conditions. The obtained pulps were characterized regarding their residual lignin content, kappa number and crystallinity index. Thus, the dependencies of the conversion during enzymatic hydrolysis on severity, pulp composition and pulp characteristics could be observed. In further experiments it was investigated how the enzymatic hydrolysis is affected by pulp drying or by a reduction of enzyme loading. Up to 83% of the initial cellulose in wood and almost 97% of the cellulose in pulp were converted into glucose using cellulases from Trichoderma reesei and β-glucosidase from Aspergillus niger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Bioremediation of agro-based pulp mill effluent by microbial consortium comprising autochthonous bacteria.

    PubMed

    Kumar, Virendra; Dhall, Purnima; Kumar, Rita; Prakash Singh, Yogendra; Kumar, Anil

    2012-01-01

    Small-scale agro-based pulp and paper mills are characterized as highly polluting industries. These mills use Kraft pulping process for paper manufacturing due to which toxic lignified chemicals are released into the environment. Lack of infrastructure, technical manpower, and research and development facilities restricts these mills to recover these chemicals. Therefore, the chemical oxygen demand (COD) of the emanating stream is quite high. For solving the above problem, four bacteria were isolated from the premises of agro-based pulp and paper mill which were identified as species of Pseudomonas, Bacillus, Pannonibacter, and Ochrobacterum. These bacteria were found capable of reducing COD up to 85%-86.5% in case of back water and 65-66% in case of back water : black liquor (60:40), respectively, after acclimatization under optimized conditions (pH 6.8, temperature 35°C, and shaking 200 rpm) when the wastewater was supplemented with nitrogen and phosphorus as trace elements.

  9. Bioremediation of Agro-Based Pulp Mill Effluent by Microbial Consortium Comprising Autochthonous Bacteria

    PubMed Central

    Kumar, Virendra; Dhall, Purnima; Kumar, Rita; Prakash Singh, Yogendra; Kumar, Anil

    2012-01-01

    Small-scale agro-based pulp and paper mills are characterized as highly polluting industries. These mills use Kraft pulping process for paper manufacturing due to which toxic lignified chemicals are released into the environment. Lack of infrastructure, technical manpower, and research and development facilities restricts these mills to recover these chemicals. Therefore, the chemical oxygen demand (COD) of the emanating stream is quite high. For solving the above problem, four bacteria were isolated from the premises of agro-based pulp and paper mill which were identified as species of Pseudomonas, Bacillus, Pannonibacter, and Ochrobacterum. These bacteria were found capable of reducing COD up to 85%–86.5% in case of back water and 65-66% in case of back water : black liquor (60 : 40), respectively, after acclimatization under optimized conditions (pH 6.8, temperature 35°C, and shaking 200 rpm) when the wastewater was supplemented with nitrogen and phosphorus as trace elements. PMID:22448126

  10. Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells.

    PubMed

    Viña-Almunia, J; Borras, C; Gambini, J; El Alamy, M; Peñarrocha, M; Viña, J

    2016-05-01

    Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ml of thermolysine for 40 minutes and sonicating the culture for one minute. Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agents.

  11. Mobilized dental pulp stem cells for pulp regeneration: initiation of clinical trial.

    PubMed

    Nakashima, Misako; Iohara, Koichiro

    2014-04-01

    Stem cell therapy is a potential strategy to regenerate the dentin-pulp complex, enabling the conservation and restoration of functional teeth. We assessed the efficacy and safety of pulp stem cell transplantation as a prelude before the initiation of clinical trials. Granulocyte-colony stimulating factor (G-CSF) induces subsets of dental pulp stem cells to form mobilized dental pulp stem cells (MDPSCs). Good manufacturing practice is a prerequisite for the isolation and expansion of MDPSCs that are enriched in stem cells, expressing a high level of trophic factors with properties of high proliferation, migration, and antiapoptotic effects and endowed with regenerative potential. The quality of clinical-grade MDPSCs was assured by the absence of abnormalities/aberrations in karyotype and the lack of tumor formation after transplantation in immunodeficient mice. Autologous transplantation of MDPSCs with G-CSF in pulpectomized teeth in dogs augmented the regeneration of pulp tissue. The combinatorial trophic effects of MDPSCs and G-CSF on cell migration, antiapoptosis, immunosuppression, and neurite outgrowth were also confirmed in vitro. Furthermore, MDPSCs from the aged donors were as potent as the young donors. It is noteworthy that there were no significant age-related changes in biological properties such as stability, regenerative potential, and expression of the senescence markers in MDPSCs. On the other hand, autologous transplantation of MDPSCs with G-CSF induced less regenerated pulp tissue in the aged dogs compared with the young dogs. In conclusion, the preclinical safety, feasibility, and efficacy of pulp regeneration by MDPSCs and G-CSF were established. Therefore, the standardization and establishment of regulatory guidelines for stem cell therapy in clinical endodontics is now a reality. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Preliminary study on dental pulp stem cell-mediated pulp regeneration in canine immature permanent teeth.

    PubMed

    Wang, Yuanyuan; Zhao, Yuming; Jia, Weiqian; Yang, Jie; Ge, Lihong

    2013-02-01

    The health of human teeth depends on the integrity of the hard tissue and the activity of the pulp and periodontal tissues, which are responsible for nutritional supply. Without the nourishing of the pulp tissue, the possibility of tooth fracture can increase. In immature permanent teeth, root development may be influenced as well. This study explored the potential of using autologous dental pulp stem cells (DPSCs) to achieve pulp regeneration in a canine pulpless model. The establishment of the pulpless animal model involved pulp extirpation and root canal preparation of young permanent incisor teeth in beagles. Autologous DPSCs were obtained from extracted first molars and expanded ex vivo to obtain a larger number of cells. The biological characteristics of canine DPSCs (cDPSCs) were analyzed both in vitro and in vivo by using the same method as used in human DPSCs. cDPSCs were transplanted into the pulpless root canal with Gelfoam as the scaffold, and root development was evaluated by radiographic and histologic analyses. cDPSCs with rapid proliferation, multiple differentiation capacity, and development potential were successfully isolated and identified both in vitro and in vivo. After they were transplanted into the pulpless root canal with Gelfoam as the scaffold, DPSCs were capable of generating pulp-like tissues containing blood vessels and dentin-like tissue. Thickening of the root canal wall was also observed. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to realize pulp regeneration in immature teeth. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  13. Effect of plantation density on kraft pulp production from red pine (Pinus resinosa Ait.)

    Treesearch

    J.Y. Zhu; G.C. Myers

    2006-01-01

    Red pine (Pinus resinosa Ait.) butt logs from 38 year old research plots were used to study the effect of plantation stand density on kraft pulp production. Results indicate that plantation stand density can affect pulp yield, unrefined pulp mean fibre length, and the response of pulp fibre length to pulp refining. However, the effect of plantation stand density on...

  14. Evaluating pulp stiffness from fibre bundles by ultrasound

    NASA Astrophysics Data System (ADS)

    Karppinen, Timo; Montonen, Risto; Määttänen, Marjo; Ekman, Axel; Myllys, Markko; Timonen, Jussi; Hæggström, Edward

    2012-06-01

    A non-destructive ultrasonic tester was developed to measure the stiffness of pulp bundles. The mechanical properties of pulp are important when estimating the behaviour of paper under stress. Currently available pulp tests are tedious and alter the fibres structurally and mechanically. The developed tester employs (933 ± 15) kHz tweezer-like ultrasonic transducers and time-of-flight measurement through (9.0 ± 2.5) mm long and (0.8 ± 0.1) mm thick fibre bundles kept at (19.1 ± 0.4) °C and (62 ± 1)% RH. We determined the stiffness of soft wood pulps produced by three kraft pulping modifications: standard kraft pulp, (5.2 ± 0.4) GPa, prehydrolysis kraft pulp, (4.3 ± 0.4) GPa, and alkali extracted prehydrolysis kraft pulp, (3.3 ± 0.4) GPa. Prehydrolysis and alkali extraction processes mainly lowered the hemicellulose content of the pulps, which essentially decreased the fibre-wall stiffness hence impairing the stiffness of the fibre networks. Our results indicate that the method allows ranking of pulps according to their stiffness determined from bundle-like samples taken at an early phase of the papermaking process.

  15. Pulp Stone, Haemodialysis, End-stage Renal Disease, Carotid Atherosclerosis

    PubMed Central

    Patil, Santosh; Sinha, Nidhi

    2013-01-01

    Objectives: The aim of this study was to determine the relationship between the presence of pulp calcification and carotid artery calcification on the dental panoramic radiographs in End Stage Renal Disease (ESRD) patients who were on haemodialysis. Methods: A total of 112 End Stage Renal Disease (ESRD) patients on who were haemodialysis participated in this study. The periapical and the panoramic radiographs for all the patients were evaluated for the presence or absence of the narrowing of the dental pulps and for pulp stones in the pulp chambers and the pulp canals. The panoramic radiographs were also evaluated to determine the carotid calcification. Results: Carotid calcifications were detected in none of the patients. 84 (74.99%) patients had dental pulp narrowing, and 38 (33.92%) patients had pulp stones. There was no statistical correlation between pulp narrowing and Carotid Artery Calcification (CAC) in the haemodialysis patient group. There was also no statistical correlation between pulp stones and CAC in the haemodialysis patients. Conclusion: However, the incidental finding of CAC on a panoramic radiograph can provide life-saving information for the vascular disease patients, but in the present study, no significant relationship was found between the presence of the pulpal calcification and CAC in the ESRD patients who were on haemodialysis. Therefore, the presence of pulp calcification does not seem to serve as a diagnostic marker for carotid atherosclerosis. PMID:23905147

  16. Pulp Vascularization during Tooth Development, Regeneration, and Therapy.

    PubMed

    Rombouts, C; Giraud, T; Jeanneau, C; About, I

    2017-02-01

    The pulp is a highly vascularized tissue situated in an inextensible environment surrounded by rigid dentin walls, with the apical foramina being the only access. The pulp vascular system is not only responsible for nutrient supply and waste removal but also contributes actively to the pulp inflammatory response and subsequent regeneration. This review discusses the underlying mechanisms of pulp vascularization during tooth development, regeneration, and therapeutic procedures, such as tissue engineering and tooth transplantation. Whereas the pulp vascular system is established by vasculogenesis during embryonic development, sprouting angiogenesis is the predominant process during regeneration and therapeutic processes. Hypoxia can be considered a common driving force. Dental pulp cells under hypoxic stress release proangiogenic factors, with vascular endothelial growth factor being one of the most potent. The benefit of exogenous vascular endothelial growth factor application in tissue engineering has been well demonstrated. Interestingly, dental pulp stem cells have an important role in pulp revascularization. Indeed, recent studies show that dental pulp stem cell secretome possesses angiogenic potential that actively contributes to the angiogenic process by guiding endothelial cells and even by differentiating themselves into the endothelial lineage. Although considerable insight has been obtained in the processes underlying pulp vascularization, many questions remain relating to the signaling pathways, timing, and influence of various stress conditions.

  17. Detection of organochlorine compounds formed during the contact of sodium hypochlorite with dentin and dental pulp.

    PubMed

    Varise, Tiago Gilioli; Estrela, Carlos; Guedes, Débora Fernandes Costa; Sousa-Neto, Manoel Damião; Pécora, Jesus Djalma

    2014-01-01

    This study used gas chromatography-mass spectrometry (GC-MS) to detect the products formed during the contact of sodium hypochlorite (NaOCl) with bovine pulp and dentin. For analysis of the products formed in the volatile phase, 11 mg of bovine pulp tissue were placed in contact with 0.5%, 2.5% and 5.25% NaOCl until complete tissue dissolution occurred. The solid phase microextraction (SPME) fiber was exposed inside the container through the cover membrane and immediately injected into the GC-MS system. 30 mg of the of dentin were kept in contact with NaOCl, and then the SPME fiber was exposed inside the container through the cover membrane for adsorption of the products and injected into the GC-MS system. The same protocol was used for the aqueous phase. For analysis of the volatile compounds, the final solution was extracted using pure ethyl ether. The suspended particulate phase of the mixture was aspirated, and ether was separated from the aqueous phase of the solution. The ether containing the products that resulted from the chemical interaction of dentin and pulp with the NaOCl was filtered and then injected into the GC-MS system for analysis of the aqueous phase. The aqueous and volatile phases of both dentin and pulp showed the formation of chloroform, hexachloroethane, dichloromethylbenzene and benzaldehyde. In conclusion, organochlorine compounds are generated during the contact of dentin and pulp with NaOCl at concentrations of 0.5%, 2.5% and 5.25%.

  18. Kinetics of liquid-solid reactions in naphthenic acid conversion and Kraft pulping

    NASA Astrophysics Data System (ADS)

    Yang, Ling

    Two liquid-solid reactions, in which the morphology of the solid changes as the reactions proceeds, were examined. One is the NA conversion in oil by decarboxylation on metal oxides and carbonates, and the other is the Kraft pulping in which lignin removal by delignification reaction. In the study of the NA conversion, CaO was chosen as the catalyst for the kinetic study from the tested catalysts based on NA conversion. Two reaction mixtures, carrier oil plus commercial naphthenic acids and heavy vacuum gas oil (HVGO) from Athabasca bitumen, were applied in the kinetic study. The influence of TAN, temperature, and catalyst loading on the NA conversion and decarboxylation were studied systematically. The results showed that the removal rate of TAN and the decarboxylation of NA were both independent of the concentration of NA over the range studied, and significantly dependent on reaction temperature. The data from analyzing the spent catalyst demonstrated that calcium naphthenate was an intermediate of the decarboxylation reaction of NA, and the decomposition of calcium naphthenate was a rate-determining step. In the study on the delignification of the Kraft pulping, a new mechanism was proposed for the heterogeneous delignification reaction during the Kraft pulping process. In particular, the chemical reaction mechanism took into account the heterogeneous nature of Kraft pulping. Lignin reacted in parallel with sodium hydroxide and sodium sulfide. The mechanism consists of three key kinetic steps: (1) adsorption of hydroxide and hydrosulfide ions on lignin; (2) surface reaction on the solid surface to produce degraded lignin products; and (3) desorption of degradation products from the solid surface. The most important step for the delignification process is the surface reaction, rather than the reactions occurring in the liquid phase. A kinetic model has, thus, been developed based on the proposed mechanism. The derived kinetic model showed that the mechanism

  19. Treatment of APMP pulping effluent based on aerobic fermentation with Aspergillus niger and post-coagulation/flocculation.

    PubMed

    Liu, Tingzhi; He, Zhibin; Hu, Huiren; Ni, Yonghao

    2011-04-01

    A novel two-stage biological/flocculation process was developed for treating the pulping effluent from the alkaline peroxide mechanical pulping (APMP) process. In the first biological stage, the aerobic fermentation by using Aspergillus niger can decrease the chemical oxygen demand (COD) by about 60% while producing about 7 g/l of solid biomass. In the second stage (post-coagulation/flocculation), the residual COD, turbidity and color, can be further decreased by using alum and polyacrylamide (PAM). The overall removal efficiencies of COD, color and turbidity from the APMP pulping effluent by the above two-stage biological-coagulation/flocculation process were 93%, 92% and 99%, respectively, under the conditions studied. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Application of hemicelluloses precipitated via ethanol treatment of pre-hydrolysis liquor in high-yield pulp.

    PubMed

    Liu, Zehua; Fatehi, Pedram; Sadeghi, Soroosh; Ni, Yonghao

    2011-10-01

    Hemicelluloses in industrially produced pre-hydrolysis liquor (PHL) were precipitated with ethanol. These PHL-derived hemicelluloses (PHL-EH) and a commercial, pure birch wood xylan sample (powder form) (BWX) were bleached using chlorine dioxide (D(0) and D(1)) and hydrogen peroxide (Ep) in the D(0)EpD(1) sequence, and the chemical compositions, molecular weights and charge densities of the treated samples were assessed. When applied to high-yield pulp (HYP) at 50 mg/g, 26 and 20 mg/g of the bleached PHL-EH and BWX, respectively, were adsorbed without significantly affecting paper properties. These results suggest that semi-bleached hemicelluloses could be used to increase the basis weight of paper products. Furthermore, an integrated process was proposed that converts the kraft-based dissolving pulp production process into a biorefinery unit with dissolving pulp, bleached hemicelluloses and lignin as main products. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. HPLC quantitative analysis of rhein and antidermatophytic activity of Cassia fistula pod pulp extracts of various storage conditions.

    PubMed

    Chewchinda, Savita; Wuthi-udomlert, Mansuang; Gritsanapan, Wandee

    2013-01-01

    Cassia fistula is well known for its laxative and antifungal properties due to anthraquinone compounds in the pods. This study quantitatively analyzed rhein in the C. fistula pod pulp decoction extracts kept under various storage conditions using HPLC. The antifungal activity of the extracts and their hydrolyzed mixture was also evaluated against dermatophytes. The contents of rhein in all stored decoction extracts remained more than 95% (95.69-100.66%) of the initial amount (0.0823 ± 0.001% w/w). There was no significant change of the extracts kept in glass vials and in aluminum foil bags. The decoction extract of C. fistula pod pulp and its hydrolyzed mixture containing anthraquinone aglycones were tested against clinical strains of dermatophytes by broth microdilution technique. The results revealed good chemical and antifungal stabilities against dermatophytes of C. fistula pod pulp decoction extracts stored under various accelerated and real time storage conditions.

  2. In vivo genotoxicity and oxidative stress evaluation of an ethanolic extract from piquiá (Caryocar villosum) pulp.

    PubMed

    Almeida, Mara Ribeiro; Aissa, Alexandre Ferro; Ursula Hermogenes Gomes, Tarsila Daysy; Darin, Joana D'Arc Castania; Chisté, Renan Campos; Mercadante, Adriana Zerlotti; Antunes, Lusânia Maria Greggi; Bianchi, Maria Lourdes Pires

    2013-03-01

    In this study, the ethanolic extract obtained from piquiá pulp was assessed for genotoxicity and oxidative stress by employing the micronucleus test in bone marrow and peripheral blood cells in addition to comet, thiobarbituric-acid-reactive substances (TBARS), and reduced glutathione assays in the liver, kidney, and heart. Additionally, phytochemical analyses were performed to identify and quantify the chemical constituents of the piquiá extract. Wistar rats were treated by gavage with an ethanolic extract from piquiá pulp (75 mg/kg body weight) for 14 days, and 24 h prior to euthanasia, they received an injection of saline or doxorubicin (15 mg/kg body weight, intraperoneally). The results demonstrated that piquiá extract at the tested dose was genotoxic but not mutagenic, and it increased the TBARS levels in the heart. Further studies are required to fully elucidate how the properties of ethanolic extract of piquiá pulp can affect human health.

  3. Durability of pulp fiber-cement composites

    NASA Astrophysics Data System (ADS)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness

  4. Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

    PubMed

    Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

    2015-09-01

    Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility.

  5. Surface and thermal enhancement of the cellulosic component of thermo mechanical pulp using a rapid method: Iodomethane modification.

    PubMed

    George, Michael; Mussone, Paolo G; Bressler, David C

    2016-05-20

    The feasibility of employing chemical methods for enhancement of cellulose-based materials is dependent on the availability, price, and green index of the modifying agent. This study details the use of iodomethane, an inexpensive organo halide, to increase the hydrophobicity of thermo mechanical (TMP) samples, which renders them better structural elements for composite materials. For this system, we studied the influence of various concentration of iodomethane, concentration of caustic, and reaction time. Infrared spectroscopy suggested reaction of the organo halide with the hydroxyl groups of cellulose and lignin components of TMP. Pulp samples treated for 4 h or at low caustic concentration showed the least improvements plausibly due to pulp degradation or poor pulp swelling, respectively. On the other hand, pulp treated at 3 h using high concentrations of caustic were characterized with surfaces that were more hydrophobic. Thus, this study outlines a fast and organic solvent-free (clean up) method that can be used to enhance pulp samples for composite applications.

  6. A new alternative use for coffee pulp from semi-dry process to β-glucosidase production by Bacillus subtilis.

    PubMed

    Dias, M; Melo, M M; Schwan, R F; Silva, C F

    2015-12-01

    Coffee is among the most preferred nonalcoholic drinks, and its consumption is distributed globally. During the coffee fruiting process, however, a large amount of waste is generated in the form of pulp, mucilage, husks, and water waste. The pulp and mucilage have the chemical composition to support the growth of micro-organisms and the production of value-added product. The aim was testify pulp coffee can be considered as carbon and inductor source for β-glucosidase by Bacillus subtilis CCMA 0087. The response surface methodology (RSM) based on a central composite rotatable design (CCRD) was employed for this optimization. The methodology used in the optimization process was validated by testing the best conditions obtained and comparing them with the values predicted by the model. The highest β-glucosidase production (22·59 UI ml(-1) ) was reached in 24 h of culturing at coffee pulp concentration of 36·8 g l(-1) , temperature of 36·6°C, and pH of 3·64. Countries whose economy is based on agricultural activities generate a great deal of liquid and solid waste. Thus, it is important to develop new alternatives for using this waste rather than disposing it in the environment. The production of enzymes, and particularly cellulase, is one such alternative. In this study, we proposed to produce β-glucosidase production from pulp coffee extract using a Bacillus subtilis strain. © 2015 The Society for Applied Microbiology.

  7. Banana (Musa spp) from peel to pulp: ethnopharmacology, source of bioactive compounds and its relevance for human health.

    PubMed

    Pereira, Aline; Maraschin, Marcelo

    2015-02-03

    Banana is a fruit with nutritional properties and also with acclaimed therapeutic uses, cultivated widely throughout the tropics as source of food and income for people. Banana peel is known by its local and traditional use to promote wound healing mainly from burns and to help overcome or prevent a substantial number of illnesses, as depression. This review critically assessed the phytochemical properties and biological activities of Musa spp fruit pulp and peel. A survey on the literature on banana (Musa spp, Musaceae) covering its botanical classification and nomenclature, as well as the local and traditional use of its pulp and peel was performed. Besides, the current state of art on banana fruit pulp and peel as interesting complex matrices sources of high-value compounds from secondary metabolism was also approached. Dessert bananas and plantains are systematic classified into four sections, Eumusa, Rhodochlamys, Australimusa, and Callimusa, according to the number of chromosomes. The fruits differ only in their ploidy arrangement and a single scientific name can be given to all the edible bananas, i.e., Musa spp. The chemical composition of banana's peel and pulp comprise mostly carotenoids, phenolic compounds, and biogenic amines. The biological potential of those biomasses is directly related to their chemical composition, particularly as pro-vitamin A supplementation, as potential antioxidants attributed to their phenolic constituents, as well as in the treatment of Parkinson's disease considering their contents in l-dopa and dopamine. Banana's pulp and peel can be used as natural sources of antioxidants and pro-vitamin A due to their contents in carotenoids, phenolics, and amine compounds, for instance. For the development of a phytomedicine or even an allopathic medicine, e.g., banana fruit pulp and peel could be of interest as raw materials riches in beneficial bioactive compounds. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Estimates of sensitivity and specificity of electric pulp testing depend on pulp disease spectrum: a modelling study.

    PubMed

    Mejàre, I A; Bergenholtz, G; Petersson, K; Tranæus, S

    2015-01-01

    To demonstrate how the spectrum of diseased pulps may influence sensitivity and specificity in diagnostic studies on pulp status. An original sample from a previous study consisting of 59 teeth scheduled for root canal treatment was used where the relationship between the response to electric pulp testing and the visual status of the pulp was evaluated. To alter the spectrum of diseased pulps, a hypothetical sample of asymptomatic teeth with deep caries lesions was added to the original sample. Sensitivity and specificity were then compared for the two samples. In the original sample of 59 teeth, sensitivity was 72% and specificity 90%. When the spectrum of diseased pulps was altered, sensitivity decreased to 67% and specificity increased to 97%. The change in disease spectrum also decreased the prevalence of necrotic pulps. The spectrum of diseased pulps included in a diagnostic study on the accuracy of electric pulp testing, and indirectly also disease prevalence (here pulp necrosis), influences estimates of sensitivity and specificity. This implies that estimates of diagnostic accuracy from one study with a particular tooth population spectrum may not apply to another tooth population with a different disease spectrum. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  9. Expression of high mobility group box 1 in inflamed dental pulp and its chemotactic effect on dental pulp cells

    SciTech Connect

    Zhang, Xufang; Jiang, Hongwei; Gong, Qimei; Fan, Chen; Huang, Yihua; Ling, Junqi

    2014-08-08

    Highlights: • HMGB1 translocated from nucleus to cytoplasm during dental pulp inflammation. • HMGB1and its receptor RAGE were up-regulated in hDPCs under LPS stimulation. • HMGB1 enhanced hDPCs migration and induces cytoskeleton reorganization. • HMGB1 may play a critical role in dental pulp repair during inflamed state. - Abstract: High mobility group box 1 protein (HMGB1) is a chromatin protein which can be released extracellularly, eliciting a pro-inflammatory response and promoting tissue repair process. This study aimed to examine the expression and distribution of HMGB1 and its receptor RAGE in inflamed dental pulp tissues, and to assess its effects on proliferation, migration and cytoskeleton of cultured human dental pulp cells (DPCs). Our data demonstrated that cytoplasmic expression of HMGB1 was observed in inflamed pulp tissues, while HMGB1 expression was confined in the nuclei in healthy dental pulp. The mRNA expression of HMGB1 and RAGE were significantly increased in inflamed pulps. In in vitro cultured DPCs, expression of HMGB1 in both protein and mRNA level was up-regulated after treated with lipopolysaccharide (LPS). Exogenous HMGB1 enhanced DPCs migration in a dose-dependent manner and induced the reorganization of f-actin in DPCs. Our results suggests that HMGB1 are not only involved in the process of dental pulp inflammation, but also play an important role in the recruitment of dental pulp stem cells, promoting pulp repair and regeneration.

  10. In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration.

    PubMed

    Kim, Sunil; Shin, Su-Jung; Song, Yunjung; Kim, Euiseong

    2015-01-01

    In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration.

  11. In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration

    PubMed Central

    Kim, Sunil; Shin, Su-Jung; Song, Yunjung; Kim, Euiseong

    2015-01-01

    In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration. PMID:26688616

  12. PDADMAC as a flocculant for lignosulfonate of NSSC pulping process.

    PubMed

    Oveissi, Farshad; Sitter, Thomas; Fatehi, Pedram

    2016-05-01

    The spent liquor (SL) of neutral sulfite semi-chemical (NSSC) pulping process contains about 8 wt% lignocelluloses that can be extracted and used in the production of value-added materials. In this work, a flocculation process followed by centrifugation was considered for isolating lignosulfonate and hemicelluloses from SL. It was observed that, by adding 20 mg/g of polydiallyldimethylammuniom chloride (PDADMAC) with 100,000-200,000 g/mol molecular weight to SL, 45% of lignosulfonate and 39% of hemicelluloses were removed at 30°C. The lignocellulose removal was more efficient for the dual flocculation system of low and high molecular weights PDADMAC than for individual PDADMAC systems. Overall, 49% of lignosulfonate, 47% of hemicelluloses and 97% of turbidity were removed from SL from the dual system when 10 mg/g low molecular weight PDADMAC and 10 mg/g high molecular weight PDADMAC were added to the SL at 30°C, subsequently. The thermogravimetric analysis (TGA) of generated flocs showed that all samples had similar thermal behaviour and 13-16 wt% of flocs remained as ash after burning at 700°C in nitrogen. As the flocs are made of lignocellulosic materials and they are thermally stable, they could be used as fillers in paper board production. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:686-691, 2016. © 2016 American Institute of Chemical Engineers.

  13. Does removal of the original pulp tissue before autotransplantation influence ingrowth of new tissue in the pulp chamber?

    PubMed

    Laureys, Wim G M; Dermaut, Luc R; Cuvelier, Claude A; De Pauw, Guy A M

    2010-10-01

    In an attempt to extend the indication area for autotransplantation of vital teeth, two possibilities can be proposed: (i) The enlargement of the apical foramen, with the aim to facilitate revascularization and ingrowth of new tissue. The ingrowth of tissue will eliminate the need for endodontic treatment when mature teeth are transplanted and (ii) the cryopreservation of teeth in case they cannot be transplanted immediately to the receptor site. Teeth with an ideal stage of root formation can be cryopreserved to perform transplantation later. Although pulpcell cultures survive crypreservation in vitro, the pulp tissue cannot survive the cryopreservation procedures when it is kept inside the pulpchamber. Therefore, the pulp tissue has to be removed before cryopreservation. It has been demonstrated that revascularization and ingrowth of new tissue can occur in an empty pulp chamber (1). The aim of this study was to find out if revascularization and ingrowth of new pulp tissue is influenced by removal of the original pulp tissue before autotransplantation. Twenty nine single-rooted teeth from three adult beagle dogs were transplanted after resection of the root tip. One group of teeth (n = 14) had the pulp tissue removed before transplantation. The other group (n = 15) had the original pulp left in situ. The transplanted teeth were histologically analysed 90 days post-transplantation. In the group with the tissue left in situ, 12 teeth (80%) showed a pulp chamber totally filled or at least 1/3 to 2/3 filled with viable tissue. In the group with the pulp tissue removed, 11 teeth (79%) had no or little vital tissue in the pulp chamber. The necrotic masses that develop in the original pulp tissue immediately after transplantation are a possible stimulating factor in the repair process of the pulp. As a conclusion, it can be stated that in case of autotransplantation of teeth, it is advisable to leave the pulp tissue in situ to stimulate the revascularization and

  14. Response of inflamed pulps of rat molars after capping with pulp-capping material containing fluocinolone acetonide.

    PubMed

    Louwakul, Phumisak; Lertchirakarn, Veera

    2015-04-01

    Capping inflamed dental pulp tissue is currently a controversial issue. To reduce pulp inflammation and stimulate pulp healing, a pulp-capping material containing fluocinolone acetonide (PCFA) has been developed. This study was aimed to evaluate the inflammatory response and hard tissue formation of inflamed dental pulps of rat maxillary molars after capping with Dycal, mineral trioxide aggregate (MTA), or PCFA. Sixty maxillary rat molars were exposed to the oral environment for 48 hours. The exposed pulps were randomly divided into 6 groups (n = 10) according to pulp-capping materials (Dycal, MTA, or PCFA) and time (8 or 30 days). The cavities were capped and sealed with Fuji II LC. The animals were sacrificed after 8 and 30 days. Histologic specimens were prepared and evaluated for inflammatory response and hard tissue formation. Eight days after pulp capping, all experimental groups showed disruption of the odontoblast layer in areas corresponding to the pulpal exposure. Acute inflammation was found in 80%, 60%, and 40% of samples in the Dycal, MTA, and PCFA groups, respectively. PCFA significantly decreased the pulp inflammation compared with Dycal. After 30 days, slight to moderate inflammation was found in all experimental groups. Hard tissue formation was found in 78%, 63%, and 100% of samples in the Dycal, MTA, and PCFA groups, respectively. No significant difference was found among the experimental groups. Pulp capping with PCFA reduced the inflammation and stimulated hard tissue formation in the exposed pulps of rat molars. It may be used as a pulp-capping agent in inflamed pulps. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Hydrothermal carbonization of pulp mill streams.

    PubMed

    Wikberg, Hanne; Ohra-Aho, Taina; Honkanen, Mari; Kanerva, Heimo; Harlin, Ali; Vippola, Minnamari; Laine, Christiane

    2016-07-01

    The progress of the conversion, the yield, the structure and the morphology of the produced carbonaceous materials as a function of time were systematically studied with pyrolysis-GC/FID and FESEM microscope. The conversion of galactoglucomannan, bleached kraft pulp and TEMPO oxidized cellulose nanofibrils followed the reaction route of glucose being slower though with fibrous material, higher molar mass and viscosity. The conversion of kraft lignin was minor following completely different reaction route. Carbonaceous particles of different shape and size were produced with yields between 23% and 73% after 4h with being higher for lignin than carbohydrates. According to the results, potential pulp mill streams represent lignocellulosic resources for generation of carbonaceous materials.

  16. Tissue Engineering Considerations in Dental Pulp Regeneration

    PubMed Central

    Nosrat, Ali; Kim, Jong Ryul; Verma, Prashant; S. Chand, Priya

    2014-01-01

    Regenerative endodontic procedure is introduced as a biologically based treatment for immature teeth with pulp necrosis. Successful clinical and radiographic outcomes following regenerative procedures have been reported in landmark case reports. Retrospective studies have shown that this conservative treatment allows for continued root development and increases success and survival rate of the treated teeth compared to other treatment options. Although the goal of treatment is regeneration of a functional pulp tissue, histological analyses show a different outcome. Developing predictable protocols would require the use of key elements for tissue engineering: stem cells, bioactive scaffolds, and growth factors. In this study we will review the evidence based steps and outcomes of regenerative endodontics. PMID:24396373

  17. Lymphatic vessels in inflamed human dental pulp.

    PubMed

    Marchetti, C; Piacentini, C; Menghini, P

    1990-01-01

    Investigation has been performed on both the light and electron microscopic characteristics of the lymphatic vessels present in the dental pulp of human teeth which have been affected by serious carious lesions. These conditions provoke a severe inflammatory response resulting in structural and functional modifications of the tissue; increase of the tissue pressure is followed by the need for a more intensive lymphatic drainage. In the inflamed pulps, dilated lymphatic vessels with distended walls and "open junctions" between endothelial cells are detectable. On the other hand they lack certain endothelial structures which characterize the morphology of these vessels under normal conditions. In the pulpal regions affected by fibrotic proliferation shrunken vessels with irregular profiles are present. From these observations it is possible to obtain other information on the mechanisms regulating the lymphatic drainage in different structural and functional conditions of the interstitium.

  18. Tooth slice/scaffold model of dental pulp tissue engineering.

    PubMed

    Sakai, V T; Cordeiro, M M; Dong, Z; Zhang, Z; Zeitlin, B D; Nör, J E

    2011-07-01

    Multipotency is a defining characteristic of post-natal stem cells. The human dental pulp contains a small subpopulation of stem cells that exhibit multipotency, as demonstrated by their ability to differentiate into odontoblasts, neural cells, and vascular endothelial cells. These discoveries highlight the fundamental role of stem cells in the biology of the dental pulp and suggest that these cells are uniquely suited for dental pulp tissue-engineering purposes. The availability of experimental approaches specifically designed for studies of the differentiation potential of dental pulp stem cells has played an important role in these discoveries. The objective of this review is to describe the development and characterization of the Tooth Slice/Scaffold Model of Dental Pulp Tissue Engineering. In addition, we discuss the multipotency of dental pulp stem cells, focusing on the differentiation of these cells into functional odontoblasts and into vascular endothelial cells.

  19. Bleaching kraft pulps with white-rot fungi

    SciTech Connect

    Reid, I.D.; Paice, M.G.; Bourbonnais, R.

    1996-10-01

    Certain white-rot fungi, notably Trametes versicolor, Phanerochaete sordida, and isolate IZU-154 can lower the residual lignin content and increase the brightness of kraft pulps without damaging the pulps` strength or yield. This biological delignification effect can be used in Elemental Chlorine Free and Totally Chlorine Free bleaching sequences. Physical contact between the fungal hyphae and the pulp fibers is not required, but the presence of the living fungus is necessary for continued delignification. In many but not a systems, delignification is correlated with manganese peroxidase activity. Experiments with pulps containing {sup 14}C-labelled lignin indicate that the residual lignin is solubilized, but not extensively mineralized, by T. versicolor. The solubilized lignin has the same molecular size as the residual lignin originally present in the pulp. Demethylation of the phenolic rings in the pulp is an early effect of incubation with the fungus.

  20. Changes in pulp web properties by addition of natural filler

    NASA Astrophysics Data System (ADS)

    Kamaludin, Nurul Hasanah; Ghazali, Arniza; Daud, Wan Rosli Wan; Ghazali, Salmi

    2012-09-01

    Development of the desired pulp-based products eco-properties are governed by factors like choice and suitability of raw material, the design and operation of pulping process and choice of additives. Fines recovered during refining discharge of an alkaline peroxide pulping system were collected based on their retention on varying mesh-sizes screens. Analysis shows that 12% of the 400-mesh fines added to the web enhances paper tensile strength by 100%. This defines the usefulness of fibrillar particles whose cell wall collapsibility increases the web density by increasing bonding ability and thus, strength of pulp-based products such as paper. The study acknowledges fines functioning as natural filler in pulp network and collection of fines from the refining discharge was found to reduce 70% turbidity and this improvement will help reduce the costs pertinent to generation of whitewater from the pulping system.

  1. Wastes from paper and pulp mills

    PubMed Central

    Makkonen, Osmo A. P.

    1956-01-01

    The disposal of wastes from paper and pulp mills—a problem of particular importance in the northern European countries of Norway, Sweden and Denmark, where wood-processing is one of the main industries—is discussed. The various types of waste produced are described, and their pollution potential is assessed, in terms of population equivalents, with special reference to the present position in Finland. The methods available for the treatment of these wastes are briefly outlined. PMID:13374536

  2. Potential sulfur-free pulping methods

    Treesearch

    Edward L. Springer; Rajai H. Atalla; Richard S. Reiner

    2002-01-01

    Lodgepole pine chips were pulped to Kappa numbers of about 70 using soda–AQ, soda–ODiMAQ, and kraft methods. At a catalyst level of 0.20% (oven-dry wood basis), cooking times for the soda cooks were significantly shorter than that for the kraft cook. The ODiMAQ catalyzed cooking time was much shorter than that of the AQ cook. It might be possible to replace the kraft...

  3. Application of toxicity tests into discharges of the pulp-paper industry in Turkey.

    PubMed

    Sponza, Delia Teresa

    2003-01-01

    The aim of this study was to investigate the acute toxicity of pulp-paper industry wastewater using traditional and enrichment toxicity tests and to emphasize the importance of toxicity tests in wastewater discharge regulations. Enrichment toxicity tests are novel applications and give an idea of whether there is potential toxicity or growth-limiting and -stimulating conditions. Different organisms were used such as bacteria (floc and coliform bacteria), algae (Chlorella sp.), protozoa (Vorticella sp.), and fish (Lepistes sp.) to represent four trophic levels. Furthermore, chemical oxygen demand (COD) fractionation results were compared with these tests to assess the effect of COD subcategories on the determination of possible toxicity. The pulp-paper industry results revealed acute toxicity to at least two organisms in 6 of 20 effluent samples. The toxicity test results were assessed with chemical analyses such as COD, biochemical oxygen demand (BOD), color, absorbable organic halogen (AOXs), and phenol. It was observed that the toxicity of the effluents could not be explained by using physicochemical analyses in four cases for the pulp-paper industry. The results clearly indicate that bioassay tests provide additional information on the toxicity potential of industrial discharges and effluents.

  4. Profiling hydroxycinnamic acid glycosides, iridoid glycosides, and phenylethanoid glycosides in baobab fruit pulp (Adansonia digitata).

    PubMed

    Li, Xing-Nuo; Sun, Jianghao; Shi, Haiming; Yu, Lucy Liangli; Ridge, Clark D; Mazzola, Eugene P; Okunji, Christopher; Iwu, Maurice M; Michel, Tchimene Kenne; Chen, Pei

    2017-09-01

    The baobab (Adansonia digitata L.) is a magnificent tree revered throughout Africa and is becoming recognized for its high nutritional and medicinal values. Despite numerous reports on the pharmacological potential, little is known about its chemical compositions. In this study, four hydroxycinnamic acid glycosides (1-4), six iridoid glycosides (5-10), and three phenylethanoid glycosides (11-13) were isolated from the dried baobab fruit pulp. Their structures were determined by means of spectroscopic analyses, including HRMS, (1)H and (13)C NMR and 2D experiments (COSY, HSQC, HMBC, and ROESY). All 13 compounds isolated were reported for the first time in the genus of Adansonia. An ultra high-performance liquid chromatography high-resolution accurate-mass mass spectrometry (UHPLC HRAM MS) method was used to conduct further investigation of the chemical compositions of the hydro-alcohol baobab fruit pulp extract. Hydroxycinnamic acid glycosides, iridoid glycosides and phenylethanoid glycosides were found to be the main components in baobab fruit pulp. Published by Elsevier Ltd.

  5. Scaffolds for dental pulp tissue engineering.

    PubMed

    Galler, K M; D'Souza, R N; Hartgerink, J D; Schmalz, G

    2011-07-01

    For tissue engineering strategies, the choice of an appropriate scaffold is the first and certainly a crucial step. A vast variety of biomaterials is available: natural or synthetic polymers, extracellular matrix, self-assembling systems, hydrogels, or bioceramics. Each material offers a unique chemistry, composition and structure, degradation profile, and possibility for modification. The role of the scaffold has changed from passive carrier toward a bioactive matrix, which can induce a desired cellular behavior. Tailor-made materials for specific applications can be created. Recent approaches to generate dental pulp rely on established materials, such as collagen, polyester, chitosan, or hydroxyapatite. Results after transplantation show soft connective tissue formation and newly generated dentin. For dentin-pulp-complex engineering, aspects including vascularization, cell-matrix interactions, growth-factor incorporation, matrix degradation, mineralization, and contamination control should be considered. Self-assembling peptide hydrogels are an example of a smart material that can be modified to create customized matrices. Rational design of the peptide sequence allows for control of material stiffness, induction of mineral nucleation, or introduction of antibacterial activity. Cellular responses can be evoked by the incorporation of cell adhesion motifs, enzyme-cleavable sites, and suitable growth factors. The combination of inductive scaffold materials with stem cells might optimize the approaches for dentin-pulp complex regeneration.

  6. Factors affecting the corrosivity of pulping liquors

    NASA Astrophysics Data System (ADS)

    Hazlewood, Patrick Evan

    Increased equipment failures and the resultant increase in unplanned downtime as the result of process optimization programs continue to plague pulp mills. The failures are a result of a lack of understanding of corrosion in the different pulping liquors, specifically the parameters responsible for its adjustment such as the role and identification of inorganic and organic species. The current work investigates the role of inorganic species, namely sodium hydroxide and sodium sulfide, on liquor corrosivity at a range of process conditions beyond those currently experienced in literature. The role of sulfur species, in the activation of corrosion and the ability of hydroxide to passivate carbon steel A516-Gr70, is evaluated with gravimetric and electrochemical methods. The impact of wood chip weathering on process corrosion was also evaluated. Results were used to identify black liquor components, depending on the wood species, which play a significant role in the activation and inhibition of corrosion for carbon steel A516-Gr70 process equipment. Further, the effect of black liquor oxidation on liquor corrosivity was evaluated. Corrosion and stress corrosion cracking performance of selected materials provided information on classes of materials that may be reliably used in aggressive pulping environments.

  7. Mechanical behaviors of molded pulp material

    NASA Astrophysics Data System (ADS)

    Ji, Hongwei; Wang, Huaiwen; Chen, Jinlong

    2008-11-01

    Many mechanical phenomena of interest for web-like materials, such as molded pulp, take place at the micro-scale. A SEM (scanning electron microscope) with SHIMADZU electrohydraulic servo experimental system was employed to study the micro-scale mechanical behavior of molded pulp materials. Uniaxial tension tests of molded pulp specimens were carried out, resulting in the stress-strain curves. Experimental results indicated that the material is not only elasticplastic, but also emplastic. The surface morphology evolution of the tensile specimen was visually monitored during the process of loading, and some SEM micrographs were captured under different load levels. Full-field deformations over an area of 190x170 μm2 were obtained using the digital image correlation method. The higher strains occurred at the fibre fines zone or around voids whereas the lower strains were obviously found at long fibres, demonstrating that the strain distribution is obviously uneven. The reason may be due to the random orientation and the fraction of the fibres, and the presence of impurities and voids as well.

  8. Bioceramic Materials and the Changing Concepts in Vital Pulp Therapy.

    PubMed

    Cao, Yangpei; Bogen, George; Lim, Jung; Shon, Won-Jun; Kang, Mo K

    2016-05-01

    Vital pulp therapy (VPT) is devised to preserve and maintain vitality of pulpally involved teeth challenged by a variety of intraoral conditions. Notable progress has been made in this field due to a better understanding of pulp physiology, improved clinical protocols and advanced bioceramic materials paired with adhesive technology. With focused case selection, conservative VPT can provide reliable treatment options for permanent teeth diagnosed with normal pulps or reversible pulpitis.

  9. Pilot scale fermentation of Jerusalem artichoke tuber pulp mashes

    SciTech Connect

    Ziobro, G.C.; Williams, L.A.

    1983-01-01

    Processing and fermentation of Jerusalem artichoke (Helianthus tuberosus L.) tuber pulp mashes were successfully carried out at pilot scales of 60 gallons and 1000 gallons. Whole tubers were pulped mechanically into a thick mash and fermented, using commercially available Saccharomyces cerevisiae and selected strains of Kluyveromyces fragilis. EtOH fermentation yields ranging from 50-70% of theoretical maximum were obtained in 3-4 days. Several problems regarding the processing and direct fermentation of tuber pulp mashes are discussed.

  10. The ups and downs of the pulp and paper industry

    SciTech Connect

    McKenna, J.C.

    1998-12-31

    The ``Up`s and Down`s of the Pulp and Paper Industry`` deals with the design, fabrication, and installation elements of upflow and downflow bleach (retention) towers utilized in the Pulp and Paper industry. Fabrication processes for the shop and field components of these systems are reviewed. In addition, an overview of the advantages of Fiberglass Reinforced Plastics (FRP), considering the changing chemistries for pulp bleaching is presented, and a number of case histories are reviewed.

  11. Characterisation of mechanical pulp fines from alkaline peroxide pulping of EFB

    NASA Astrophysics Data System (ADS)

    Kamaludin, Nurul Hasanah; Ghazali, Arniza; Daud, Wan Rosli Wan

    2012-09-01

    EFB (empty fruit bunch) was subjected to alkaline peroxide pulping for generation of fibrous mass as raw material for the making of pulp-based products. During refining, co-produced fines were collected by fractionation on square-mesh screens of 200-, 250-, 300- and 400- mesh sizes, placed at the refining discharge by order of increasing mesh. Each set of the produced paper was incorporated with 12% fines for microscopic analysis. It appears that sheared vessel elements and fibrils were predominant and they make up the mass rendering collapsibility of cell wall for good product formation. The study acknowledged the form of fines functioning as natural filler in pulp network and worthy of utilization for reduction of total suspended solid.

  12. Towards a new concept of lignin condensation in kraft pulping. Initial results.

    PubMed

    Gellerstedt, Göran; Majtnerova, Andrea; Zhang, Liming

    2004-01-01

    In kraft pulping, a comparatively large amount of lignin remains in the fibres after the cook. Based on various analytical techniques for lignin, such as thioacidolysis, GPC and NMR, it is suggested that lignin condensation reactions take place during the cook. The reaction seems, however, not to involve ionic intermediates as has been suggested previously but rather a one-electron mechanism with elemental sulphur as the initiator. Support for such a reaction has been found through kraft cooks in the presence of an added phenol, 2,6-xylenol, as well as through NMR analysis of kraft lignin. It was found that the added phenol is incorporated in the pulp lignin with linkages indicative of radical coupling. Furthermore, kraft lignin was found to contain substantial amounts of chemically linked fatty acids. By complementary analyses of sulphur and polysulphide in an industrial black liquor, the presence of these compounds throughout a kraft cook was demonstrated.

  13. The use of laccase in bleaching of pulps and effluent treatment

    SciTech Connect

    Goncalves, M.L.F.C.; Steiner, W.

    1996-10-01

    The use of enzymes in pulp bleaching was first reported on an industrial scale in 1986, with the discovery that xylanase aided chlorine bleaching produced up to 25% savings on chemicals. The search for more effective enzymes, turned attention to those known to act on lignin, and laccases took a leading role with their action enhanced by mediators. Laccases, have also been used for long time free or immobilized in detoxification and decolorization of waters containing phenolic pollutants. Several patented processes have been reported in recent years, and many are currently being developed or improved. This presentation will give an overview of current state of the art in literature and will discuss recent developments and applications of laccases for bleaching and for effluent treatment in the pulp and paper industry.

  14. In vitro antibacterial activity of different pulp capping materials

    PubMed Central

    Beltrami, Riccardo; Colombo, Marco; Ceci, Matteo; Dagna, Alberto; Chiesa, Marco

    2015-01-01

    Background Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Material and Methods Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials. Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping materials were recorded and compared for each bacterial strain. Results For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition zones. Conclusions MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based materials which present an higher antibacterial activity. Key words:Agar disc diffusion test, antimicrobial activity, calcium hydroxide, MTA, pulp capping materials. PMID:26644833

  15. Association between dental pulp stones and calcifying nanoparticles

    PubMed Central

    Zeng, Jinfeng; Yang, Fang; Zhang, Wei; Gong, Qimei; Du, Yu; Ling, Junqi

    2011-01-01

    The etiology of dental pulp stones, one type of extraskeletal calcification disease, remains elusive to date. Calcifying nanoparticles (CNPs), formerly referred to as nanobacteria, were reported to be one etiological factor in a number of extraskeletal calcification diseases. We hypothesized that CNPs are involved in the calcification of the dental pulp tissue, and therefore investigated the link between CNPs and dental pulp stones. Sixty-five freshly collected dental pulp stones, each from a different patient, were analyzed. Thirteen of the pulp stones were examined for the existence of CNPs in situ by immunohistochemical staining (IHS), indirect immunofluorescence staining (IIFS), and transmission electron microscope (TEM). The remaining 52 pulp stones were used for isolation and cultivation of CNPs; the cultured CNPs were identified and confirmed via their shape and growth characteristics. Among the dental pulp stones examined in situ, 84.6% of the tissue samples staines positive for CNPs antigen by IHS; the corresponding rate by IIFS was 92.3 %. In 88.2% of the cultured samples, CNPs were isolated and cultivated successfully. The CNPs were visible under TEM as 200–400 nm diameter spherical particles surrounded by a compact crust. CNPs could be detected and isolated from a high percentage of dental pulp stones, suggesting that CNPs might play an important role in the calcification of dental pulp. PMID:21289988

  16. Association between dental pulp stones and calcifying nanoparticles.

    PubMed

    Zeng, Jinfeng; Yang, Fang; Zhang, Wei; Gong, Qimei; Du, Yu; Ling, Junqi

    2011-01-07

    The etiology of dental pulp stones, one type of extraskeletal calcification disease, remains elusive to date. Calcifying nanoparticles (CNPs), formerly referred to as nanobacteria, were reported to be one etiological factor in a number of extraskeletal calcification diseases. We hypothesized that CNPs are involved in the calcification of the dental pulp tissue, and therefore investigated the link between CNPs and dental pulp stones. Sixty-five freshly collected dental pulp stones, each from a different patient, were analyzed. Thirteen of the pulp stones were examined for the existence of CNPs in situ by immunohistochemical staining (IHS), indirect immunofluorescence staining (IIFS), and transmission electron microscope (TEM). The remaining 52 pulp stones were used for isolation and cultivation of CNPs; the cultured CNPs were identified and confirmed via their shape and growth characteristics. Among the dental pulp stones examined in situ, 84.6% of the tissue samples staines positive for CNPs antigen by IHS; the corresponding rate by IIFS was 92.3 %. In 88.2% of the cultured samples, CNPs were isolated and cultivated successfully. The CNPs were visible under TEM as 200-400 nm diameter spherical particles surrounded by a compact crust. CNPs could be detected and isolated from a high percentage of dental pulp stones, suggesting that CNPs might play an important role in the calcification of dental pulp.

  17. Functionalized scaffolds to control dental pulp stem cell fate

    PubMed Central

    Piva, Evandro; Silva, Adriana F.; Nör, Jacques E.

    2014-01-01

    Emerging understanding about interactions between stem cells, scaffolds and morphogenic factors has accelerated translational research in the field of dental pulp tissue engineering. Dental pulp stem cells constitute a sub-population of cells endowed with self-renewal and multipotency. Dental pulp stem cells seeded in biodegradable scaffolds and exposed to dentin-derived morphogenic signals give rise to a pulp-like tissue capable of generating new dentin. Notably, dentin-derived proteins are sufficient to induce dental pulp stem cell differentiation into odontoblasts. Ongoing work is focused on developing ways of mobilizing dentin-derived proteins and disinfecting the root canal of necrotic teeth without compromising the morphogenic potential of these signaling molecules. On the other hand, dentin by itself does not appear to be capable of inducing endothelial differentiation of dental pulp stem cells, despite the well known presence of angiogenic factors in dentin. This is particularly relevant in the context of dental pulp tissue engineering in full root canals, where access to blood supply is limited to the apical foramina. To address this challenge, scientists are looking at ways to use the scaffold as a controlled release device for angiogenic factors. The aim of this manuscript is to present and discuss current strategies to functionalize injectable scaffolds and customize them for dental pulp tissue engineering. The long-term goal of this work is to develop stem cell-based therapies that enable the engineering of functional dental pulps capable of generating new tubular dentin in humans. PMID:24698691

  18. Functional Properties of Tooth Pulp Neurons Responding to Thermal Stimulation

    PubMed Central

    Ahn, D.K.; Doutova, E.A.; McNaughton, K.; Light, A.R.; Närhi, M.; Maixner, W.

    2012-01-01

    The response properties of tooth pulp neurons that respond to noxious thermal stimulation of the dental pulp have been not well-studied. The present study was designed to characterize the response properties of tooth pulp neurons to noxious thermal stimulation of the dental pulp. Experiments were conducted on 25 male ferrets, and heat stimulation was applied by a computer-controlled thermode. Only 15% of tooth pulp neurons (n = 39) responded to noxious thermal stimulation of the teeth. Tooth pulp neurons were found in both the superficial and deep nuclear regions of the subnucleus caudalis (Vc) and in the interface between the nucleus caudalis and interpolaris (Vc/Vi). Thirty-seven neurons had cutaneous receptive fields and were classified as either NS (16) or WDR (21) neurons. Repeated heat stimulation of the dental pulp sensitized and increased the number of electrically evoked potentials of tooth pulp neurons. These results provide evidence that both the Vc and Vc/Vi regions contain neurons that respond to noxious thermal stimulation of the dental pulp, and that these cells may contribute to the sensitization process associated with symptomatic pulpitis. PMID:22257665

  19. Ultrastructural changes in feline dental pulp with periodontal disease.

    PubMed

    Ghoddusi, Jamileh

    2003-08-01

    A light and transmission electron microscopic study was conducted on dental pulp on cats suffering periodontal disease. After extraction, pulp tissues were fixed and embedded in Epon-Araldite. Thick layers of predentin (50 microm) and odontoblasts (30 microm) were observed. In thin sections, odontoblasts showed many mitochondria and secretary vesicles. Some capillaries with several fenestrations were located within the odontoblastic layer. All the sections of pulp examined displayed a generalized infiltration of chronic inflammatory cells. Fibroblasts displayed lytic changes in some areas. These findings imply that the pulp is significantly affected by periodontal disease and furcation-involved teeth should be a carefully considered factor when dental treatment is planned.

  20. In vitro antibacterial activity of different pulp capping materials.

    PubMed

    Poggio, Claudio; Beltrami, Riccardo; Colombo, Marco; Ceci, Matteo; Dagna, Alberto; Chiesa, Marco

    2015-12-01

    Direct pulp capping involves the application of a dental material to seal communications between the exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont). Streptococcus salivarius, Streptococcus sanguis and Streptococcus mutans strains were selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials. Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping materials were recorded and compared for each bacterial strain. For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition zones. MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based materials which present an higher antibacterial activity. Agar disc diffusion test, antimicrobial activity, calcium hydroxide, MTA, pulp capping materials.

  1. Simultaneous bench scale production of dissolving grade pulp and valuable hemicelluloses from softwood kraft pulp by ionic liquid extraction.

    PubMed

    Laine, Christiane; Asikainen, Sari; Talja, Riku; Stépán, Agnes; Sixta, Herbert; Harlin, Ali

    2016-01-20

    Ionic liquid extraction of wood pulp has been highlighted as a highly potential new process for dissolving pulp production. Coproduction with a polymeric hemicellulose fraction was demonstrated in bench scale from softwood kraft pulp using extraction with the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc) and water. In total, the recovered pulp and hemicellulose fraction together yielded 95.5 wt.% of the pulp input. The extracted pulp had a remarkably high purity with an R18-value of 97.8%. The hemicellulose fraction consisted of galactoglucomannan, arabinoxylan and some cellulose and was precipitated from the ionic liquid-water mixture. After hydroxypropylation of the hemicellulose fraction, films were prepared and barrier and strength properties were compared to films from other polysaccharides. Reduced oxygen and water vapor permeation and good strength properties were demonstrated when compared to corresponding films from hydroxypropylated xylan from cold caustic extraction. The films have potential for applications in food packaging and edible films.

  2. In vitro acaricidal activity of Crescentia cujete L. fruit pulp against Rhipicephalus microplus.

    PubMed

    Pereira, Sinval Garcia; de Araújo, Sandra Alves; Guilhon, Giselle Maria Skelding Pinheiro; Santos, Lourivaldo Silva; Junior, Livio Martins Costa

    2017-05-01

    Cattle tick (Rhipicephalus microplus) is an important constraint on livestock production, particularly in tropical and subtropical areas. Synthetic acaricides are the primary method of control this thick. Resistance of R. microplus to synthetic acaricides has given rise to the need of new scientific investigations on alternative ways to control it. The objective of this work was to conduct a chemical investigation of Crescentia cujete L. fruit pulp and to evaluate the acaricide effect on R. microplus larvae of extracts, fractions, and isolated substances from this species. Crescentia cujete is a Bignoniaceae and it is characteristic of tropical climates. Its most distinctive feature is its fruit, which is spherical and gourd-like, with a hard woody shell and gelatinous pulp. The fruit pulp of C. cujete was extracted with ethanol by maceration yielding an extract and a residue. The extract was partitioned giving an ethyl acetate phase (EAF) that was fractionated by chromatographic procedures yielding cinnamic acid and benzoic acid. The remained botanic material from the ethanol extraction was further and successively extracted with ethyl ether and methanol under reflux. The acaricide effect of all extracts and fractions was evaluated against R. microplus using the larval packet test. The best result was observed for the EAF that caused 100% of mortality when a 10% solution was used and with LC50 of 5.9%. Cinnamic acid was also tested showing 63.0% of mortality with LC50 of 6.6% at the same concentrations and time of the experiment. The data obtained in this study provides information related to the chemical nature and the acaricide activity of the C. cujete epicarp that has not been previously reported. This study shows that the ethyl acetate phase of the ethanol extract of C. cujete fruit pulp is a potential alternative control for R. microplus and its activity is in part associated to cinnamic acid, its major compound.

  3. Optimization of ECF bleaching of kraft pulp. Part 1, Optimal bleaching of hardwood pulps made with different alkali charges

    Treesearch

    Thomas J. McDonough; Shunichiro Uno; Alan W. Rudie; Charles E. Courchene

    2008-01-01

    In an earlier modeling study, we showed that when a hardwood kraft pulp is bleached in the D0(EO)D1ED2 sequence with a D0 stage kappa factor of 0.20, the brightness of the pulp emerging from the D2 stage can be accurately predicted from the brightness of the pulp entering that stage. The entering brightness, in turn is a well-defined function of the ratio of the D1...

  4. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    NASA Astrophysics Data System (ADS)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  5. Sugarcane bagasse pulps: biobleaching with commercial cartazyme HS and with Bacillus pumilus xylanase.

    PubMed

    Moriya, Regina Y; Gonçalves, Adilson R; Duarte, Marta C T

    2005-01-01

    Organosolv (ethanol/water and acetosolv) pulps were treated with Bacillus pumilus xylanase for 4, 8, and 12 h and compared with commercial Cartazyme HS xylanase-treated pulps. Treatment of ethanol/water pulps with B. pumilus xylanase increased viscosity by 40% in 8 h of treatment compared with pulps treated without enzyme. However, acetosolv pulps treated with B. pumilus xylanase lost viscosity. Ethanol/water pulps treated with Cartazyme had a viscosity of 18.5 cP in 4 h of treatment. In the acetosolv pulps treated with commercial enzyme, the loss of viscosity was 20% compared with pulps treated without enzyme. Ethanol/water pulps treated with B. pumilus and Cartazyme had similar effects: a 44% reduction in kappa number for pulps treated with enzyme followed by alkaline extraction compared with pulps treated with alkaline extraction. In acetosolv pulps treated with B. pumilus, the kappa number was from 12 to 18, compared with pulps treated without enzyme, which had a 40% reduction in 4 and 12 h and a 60% reduction in 8 h. Cartazyme-treated acetosolv pulps had a kappa number of 14 in 4 and 8 h of treatment. For 12 h of treatment, the kappa number was 8. Fourier transform infrared spectra of the pulps showed that enzyme-treated pulps had changes in the 1000 cm-1 absorption owing to a C-O bond present in esters. Using principal component analysis, it is possible to differentiate the unbleached pulps and enzyme-treated pulps.

  6. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    PubMed

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A comparative histological analysis of human pulp following direct pulp capping with Propolis, mineral trioxide aggregate and Dycal.

    PubMed

    Parolia, A; Kundabala, M; Rao, N N; Acharya, S R; Agrawal, P; Mohan, M; Thomas, M

    2010-03-01

    Permanent teeth pulp exposures have traditionally been treated with calcium hydroxide pulp capping. The aim of this study was to investigate the response of human pulp tissue which were mechanically exposed to a new material, Propolis and compare it with two existing and commonly used pulp capping agents (mineral trioxide aggregate and Dycal). Thirty-six intact human premolars were mechanically exposed. Teeth were divided into six groups of 6 teeth each and were capped with Propolis, mineral trioxide aggregate and Dycal. Final restoration was done with posterior composite resin using light cured glass ionomer cement as a liner. The teeth were then extracted on the 15th or the 45th day and processed for histological evaluation. Differences in inflammatory response and dentine bridge formation of the exposed pulp to the three different materials were statistically calculated using chi-square test and were found to be non-significant. There was more pulp inflammation in teeth treated with Dycal than with Propolis and MTA on the 15th as well as on the 45th day. Propolis and MTA showed bridge formation in more teeth, and the bridges were in closer proximity to pulp capping material than teeth treated with Dycal on the 45th day. The response of pulps to Propolis as a pulp capping agent was comparable to MTA and Dycal.

  8. The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp.

    PubMed

    Macoris, Mariana S; De Marchi, Renata; Janzantti, Natália S; Monteiro, Magali

    2012-07-01

    This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin-Ciocalteu reaction, and TAA using the ABTS radical reaction. The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L⁻¹ (P ≤ 0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L⁻¹ (P ≤ 0.05) for the conventional pulp. TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry.

  9. Process controls for improving bioleaching performance of both Li and Co from spent lithium ion batteries at high pulp density and its thermodynamics and kinetics exploration.

    PubMed

    Niu, Zhirui; Zou, Yikan; Xin, Baoping; Chen, Shi; Liu, Changhao; Li, Yuping

    2014-08-01

    Release of Co and Li from spent lithium ion batteries (LIBs) by bioleaching has attracted growing attentions. However, the pulp density was only 1% or lower, meaning that a huge quantity of media was required for bioleaching. In this work, bioleaching behavior of the spent LIBs at pulp densities ranging from 1% to 4% was investigated and process controls to improve bioleaching performance at pulp density of 2% were explored. The results showed that the pulp density exerted a considerable influence on leaching performance of Co and Li. The bioleaching efficiency decreased respectively from 52% to 10% for Co and from 80% to 37% for Li when pulp density rose from 1% to 4%. However, the maximum extraction efficiency of 89% for Li and 72% for Co was obtained at pulp density of 2% by process controls. Bioleaching of the spent LIBs has much greater potential to occur than traditional chemical leaching based on thermodynamics analysis. The product layer diffusion model described best bioleaching behavior of Co and Li.

  10. Pilot study of correlation of pulp stones with cardiovascular disease.

    PubMed

    Edds, A C; Walden, J E; Scheetz, J P; Goldsmith, L J; Drisko, C L; Eleazer, P D

    2005-07-01

    We propose that calcification of dental pulp may have a similar pathogenesis as calcified atheromas and could lead to use of routine dental radiographs as a rapid screening method for early identification of potential cardiovascular disease (CVD). Fifty-five dental patients ages 20 to 55 were chosen because pulp stones in pulpally noninflamed teeth were not expected in this age group. They completed a questionnaire regarding their CVD status and that of their parents and siblings. Entry criteria included at least one asymptomatic, minimally restored, noncarious molar and no history of gout, renal disease, or renal lithiasis. Patients' periapical radiographs of record were viewed to determine the presence of pulp stones. There was a significant relationship between pre-existing CVD and pulp stones (odds ratio of 4.4 with a 95% confidence interval of 1.1, 18.7), but no relationship was found for family history of CVD and pulp stones (odds ratio of 1.7 with a 95% confidence interval of 0.5, 5.5). Seventy-four percent (14/19) of patients with reported CVD had detectable pulp stones while only 39% (14/36) of patients without a history of CVD had pulp stones. This pilot study demonstrates that patients with CVD have an increased incidence of pulp stones in teeth with noninflamed pulps compared to patients with no history of CVD. No relationship was found between presence of pulp stones and family history of CVD. The findings suggest that dental radiographic determination of the presence or absence of pulp stones may have possibilities for use in CVD screening.

  11. Fate of wood extractives in wastewater treatment plants at kraft pulp mills and mechanical pulp mills.

    PubMed

    Kostamo, A; Holmbom, B; Kukkonen, J V K

    2004-02-01

    Extensive environmental effects of the forest industry led to implementation of activated sludge treatment of effluents in the 1980s. Although the existence of chlorinated compounds in the effluents has decreased, a discussion about the possible environmental effects of elemental-chlorine-free (ECF) and total-chlorine-free (TCF) bleached pulp mill effluents has arisen, and chronic effects on aquatic organisms have still been found. Recently, studies have mainly focussed on wood extractives and their role in the effects of effluents. Resin acids and unsaturated fatty acids are found to be toxic, and plant sterols are reported to have adverse endocrine effects on water organisms already at low concentrations. In this study, Finnish wastewater treatment plants of an ECF kraft pulp mill, a paper mill, and an integrated TCF kraft pulp and paper mill were sampled in order to ascertain how wastewater treatment plants, and especially activated sludge treatments, remove wood extractives. Concentrations of extractives in discharged wastewaters varied between 0.4 and 11 g/t kraft or mechanical pulp, and the concentrations decreased over 95% during the treatment processes. Of the wood extractives, 1.1-64% were adsorbed to biosludge and 35-99% were degraded or transformed to other forms during the activated sludge treatment. A major part of these compounds were discharged in particles (74-99%). The removal of extractives was efficient even in the effluent treatment plant, which was highly loaded during the sampling period.

  12. Cell-derived micro-environment helps dental pulp stem cells promote dental pulp regeneration.

    PubMed

    Zhang, Xuexin; Li, Hui; Sun, Jingjing; Luo, Xiangyou; Yang, Hefeng; Xie, Li; Yang, Bo; Guo, Weihua; Tian, Weidong

    2017-10-01

    The function of the dental pulp is closely connected to the extracellular matrix (ECM) structure, and ECM has received significant attention due to its biological functions for regulating cells. As such, the interaction between the ECM niche and cells is worth exploring for potential clinical uses. In this study, dental pulp stem cell (DPSC)-derived ECM (DPM) was prepared through cell culture and decellularization to function as the cell niche, and changes in DPSC behaviour and histological analysis of dental pulp tissue regeneration were evaluated following the DPM culture. DPM promoted the replication of DPSCs and exhibited retention of their mineralization. Then, the DPM-based culture strategy under odontogenic culture medium was further investigated, and the mineralization-related markers showed that DPSCs were regulated towards odontogenic differentiation. Dental pulp-like tissue with well-arranged ECM was harvested after a 2-month subcutaneous implantation in nude mice with DPM application. Additionally, DPSCs cultured on the plastic culture surface showed the up-regulation of mineralization makers in vitro, but there was a disorder in matrix formation and mineralization when the cells were cultured in vivo. DPM-based cultivation could serve as a cell niche and modulate DPSC behaviour, and this method also provided an alternative to harvest tissue-specific ECM and provided a strategy for ECM-cell interaction. © 2017 John Wiley & Sons Ltd.

  13. Free toe pulp flap for finger pulp and volar defect reconstruction

    PubMed Central

    Balan, Jyoshid R.

    2016-01-01

    Background: Fingertip injury requiring flap cover is very common in the modern era. The ideal cover should fulfill both functional and aesthetic improvement. Materials and Methods: From June 2015 to April 2016, we performed seven free toe pulp flaps for finger defect reconstruction. All patients were males. Five flaps were done in emergency post-traumatic cases, and two were done in elective set up. The cases included reconstruction of three thumbs, one index and one ring finger in an emergency set up and two ring fingers in the elective. Thumb reconstruction was done with great toe lateral pulp and the other digits reconstructed with second toe pulp flap. Follow-up evaluation included both functional and aesthetic assessment. Results: Five flaps survived completely, one suffered partial loss, and one flap failed completely. The median follow-up period was 9 months. The median duration of surgery was 255 min (range 210 to 300 min). The median two-point discrimination was 6.5 mm (range 4–8 mm). There was the return of temperature sensation in all patients; two had cold intolerance. The Semmes-Weinstein monofilament score varied from 3.61 to 5.07 (median filament index value 4.31/pressure value of 2 g/mm2). Three patients had delayed donor site wound healing. Conclusions: The free toe pulp flap is an efficient choice for fingertip and volar finger defects reconstruction with an excellent tissue match. PMID:27833279

  14. Problems in Pulps: A Study of Special Collections in Pulp Magazines.

    ERIC Educational Resources Information Center

    Tuttle, George

    Heads of special collections of pulp magazines, the medium for popular fiction prior to the introduction of mass market paperbacks in 1939, were surveyed to help analyze and address the problems facing these collections. A survey mailed to special collections administrators gathered background information from the four largest collections…

  15. Indirect pulp capping versus pulpotomy for treating deep carious lesions approaching the pulp in primary teeth: a systematic review.

    PubMed

    Smaïl-Faugeron, V; Porot, A; Muller-Bolla, M; Courson, F

    2016-06-01

    To assess dental practice regarding the use of indirect pulp capping or pulpotomy in children with deep carious lesions approaching the pulp in primary teeth and to compare the efficacy of the two pulp treatments. Systematic review. We searched the Cochrane Library, PubMed via MEDLINE, and EMBASE as well as the reference lists of included reports and ClinicalTrials.gov (for ongoing trials). Eligible studies were surveys of dental practice sent to dentists regarding the use of indirect pulp capping and pulpotomy in children with deep carious lesions approaching the pulp in primary teeth and any type of clinical study. Two review authors independently extracted data and assessed risk of bias in duplicate. Of the 481 potentially eligible articles, 11 were included in the review: 8 described surveys of dental practice, 1 a non-randomised study, and 2 ongoing randomised trials. The surveys of dental practice showed an overall increase in the teaching and practice of indirect pulp capping in primary teeth. The non- randomised study found a statistically significant difference in favour of indirect pulp capping for clinical and radiological success at 3 years but with high overall risk of bias. Despite the success rate of indirect pulp capping for treating deep carious lesions approaching the pulp in primary teeth, practitioners still hesitate to practice this technique because of lack of evidence and studies on this topic. Thus, for strong evidence, investigators are encouraged to conduct randomised trials comparing the efficacy of indirect pulp capping and pulpotomy for treating deep carious lesions approaching the pulp in primary teeth.

  16. 78 FR 31315 - Kraft Pulp Mills NSPS Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... May 23, 2013 Part IV Environmental Protection Agency 40 CFR Part 60 Kraft Pulp Mills NSPS Review...; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 60 RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The EPA is proposing revisions to the new source...

  17. Corvidae feather pulp and West Nile virus detection

    USGS Publications Warehouse

    Docherty, D.E.; Romaine Long, R.; Griffin, Katie M.; Saito, E.K.

    2004-01-01

    We evaluated cloacal swab, vascular pulp of flight feather, and kidney and spleen pool samples from carcasses of members of the family Corvidae as sources of West Nile virus (WNV). The cloacal swab, kidney and spleen pool, and feather pulp were the source of WNV in 38%, 43%, and 77%, respectively, of the carcasses.

  18. Inflammatory effect of green propolis on dental pulp in rats.

    PubMed

    Esmeraldo, Mabel Rodrigues Alves; Carvalho, Maria Goretti Freire de; Carvalho, Rejane Andrade de; Lima, Rennaly de Freitas; Costa, Edja Maria Melo de Brito

    2013-01-01

    Pulpotomy in deciduous teeth is a controversial issue, especially with regard to alternative materials used for the direct pulp capping of the root canal pulp tissue. The aim of the present study was to perform a histological analysis of the initial reaction of the root canal pulp tissue in rats, following pulpotomy and pulp capping with (1) green propolis extract, (2) iodoform paste, (3) green propolis extract + iodoform and (4) calcium hydroxide paste with saline solution. Analyses were performed after 24 hours, 72 hours and 7 days. The substances containing green propolis extract and iodoform led to the production of an intense inflammatory infiltrate and necrosis in the root canal pulp tissue throughout the analyses. In the calcium hydroxide group, inflammatory infiltrate only prevailed at the 72-hour evaluation. Among the substances tested, calcium hydroxide paste induced the lowest intensity of inflammatory response in the root canal pulp tissue. Longer studies should be carried out to analyze the pulp repair process following pulpotomy and pulp capping with the compounds analyzed.

  19. A Radiographic Correlation between Renal and Pulp Stones

    PubMed Central

    Ertas, E Tarim; Inci, M; Demirtas, A; Ertas, H; Yengil, E; Sisman, Y; Gokce, C

    2014-01-01

    ABSTRACT Aim: The purpose of this study was to determine the correlation between pulp stones and renal stones. This study also aimed to report associations between the presence of pulp stone and gender, age, tooth type, dental arches and sides. Patients and Methods: Data were collected through examination of bitewing radiographs of 116 kidney stone patients and a similar number of age-matched controls, referred to the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Erciyes University. Two oral radiologists examined the radiographs to identify pulp stones. The Chi-squared and Mann Whitney U tests were used to investigate the correlations between the presence of pulp chamber calcification and age, gender, dental status and kidney stone. Results: Pulp chamber opacities were detected in 199 (19.3%) out of the 1031 examined teeth, and in 84 (72.4%) out of the 116 kidney stone patients. There was no statistically significant difference between the study and control group (p = 0.882). The occurrence of pulp stones was significantly higher in molars than premolars and similar prevalences were found between dental arches and sides. Conclusion: In this study, no correlation was found between the presence of pulp stones and kidney stones in the investigated group. Therefore, the presence of pulp stones does not seem to be correlated with that of kidney stones. PMID:25803378

  20. Matrix Metalloproteinase-3 Accelerates Wound Healing following Dental Pulp Injury

    PubMed Central

    Zheng, Li; Amano, Kazuharu; Iohara, Koichiro; Ito, Masataka; Imabayashi, Kiyomi; Into, Takeshi; Matsushita, Kenji; Nakamura, Hiroshi; Nakashima, Misako

    2009-01-01

    Matrix metalloproteinases (MMPs) are implicated in a wide range of physiological and pathological processes, including morphogenesis, wound healing, angiogenesis, inflammation, and cancer. Angiogenesis is essential for reparative dentin formation during pulp wound healing. The mechanism of angiogenesis, however, still remains unclear. We hypothesized that certain MMPs expressed during pulp wound healing may support recovery processes. To address this issue, a rat pulp injury model was established to investigate expression of MMPs during wound healing. Real-time RT-PCR analysis showed that expression MMP-3 and MMP-9 (albeit lower extent) was up-regulated at 24 and 12 hours after pulp injury, respectively, whereas expression of MMP-2 and MMP-14 was not changed. MMP-3 mRNA and protein were localized in endothelial cells and/or endothelial progenitor cells in injured pulp in vivo. In addition, MMP-3 enhanced proliferation, migration, and survival of human umbilical vein endothelial cells in vitro. Furthermore, the topical application of MMP-3 protein on the rat-injured pulp tissue in vivo induced angiogenesis and reparative dentin formation at significantly higher levels compared with controls at 24 and 72 hours after treatment, respectively. Inhibition of endogenous MMP-3 by N-Isobutyl-N-(4-methoxyphenylsulfonyl)-glycylhydroxamic acid resulted in untoward wound healing. These results provide suggestive evidence that MMP-3 released from endothelial cells and/or endothelial progenitor cells in injured pulp plays critical roles in angiogenesis and pulp wound healing. PMID:19834065

  1. Electrochemical delignification of wood pulp using polyoxometalate mediators

    Treesearch

    R.S. Reiner; E.L. Springer; R.H. Atalla

    2003-01-01

    It has been found that polyoxometalates (POMs) can act as mediators in the electrochemical oxidation of lignin in pulps. An electrochemical cell, with a Nafion® membrane separating the anode and cathode compartments, was used in the delignification experiments. A softwood kraft pulp was placed in the anode compartment with a buffered 0.01M solution of the...

  2. Aetiology, classification and pathogenesis of pulp and periapical disease.

    PubMed

    López-Marcos, Joaquín F

    2004-01-01

    At present, the majority of the treatments that are performed in the clinic are due to disease entities involving the dental pulp and periapex. Dental pulp is a richly vascularized and innervated tissue, enclosed by surrounding tissues that are incapable of expanding, such as dentin. It has terminal blood flow and small-gauge circulatory access the periapex. All of these characteristics severely constrain the defensive capacity of the pulp tissue when faced with the different aggressions it may be subjected to. Pulp tissue can also be affected by a retrograde infection, arising from the secondary canaliculi, from the periodontal ligament or from the apex during the course of periodontitis. Due to the fact that periapical disease is almost inevitably preceded by pulp disease, we shall begin by describing the causes of pulp disease and will then proceed to a discussion of the causes of periapical disease. The course of illness and classification of these pathological entities will depend on the aetiology involved. We will analyse pulp necrosis and pulp degeneration that are capable of triggering reversible apical periodontitis or irreversible apical periodontitis.

  3. Axonal Degeneration in Dental Pulp Precedes Human Primary Teeth Exfoliation.

    PubMed

    Suzuki, K; Lovera, M; Schmachtenberg, O; Couve, E

    2015-10-01

    The dental pulp in human primary teeth is densely innervated by a plethora of nerve endings at the coronal pulp-dentin interface. This study analyzed how the physiological root resorption (PRR) process affects dental pulp innervation before exfoliation of primary teeth. Forty-four primary canine teeth, classified into 3 defined PRR stages (early, middle, and advanced) were fixed and demineralized. Longitudinal cryosections of each tooth were stained for immunohistochemical and quantitative analysis of dental pulp nerve fibers and associated components with confocal and electron microscopy. During PRR, axonal degeneration was prominent and progressive in a Wallerian-like scheme, comprising nerve fiber bundles and nerve endings within the coronal and root pulp. Neurofilament fragmentation increased significantly during PRR progression and was accompanied by myelin degradation and a progressive loss of myelinated axons. Myelin sheath degradation involved activation of autophagic activity by Schwann cells to remove myelin debris. These cells expressed a sequence of responses comprising dedifferentiation, proliferative activity, GAP-43 overexpression, and Büngner band formation. During the advanced PRR stage, increased immune cell recruitment within the dental pulp and major histocompatibility complex (MHC) class II upregulation by Schwann cells characterized an inflammatory condition associated with the denervation process in preexfoliative primary teeth. The ensuing loss of dental pulp axons is likely to be responsible for the progressive reduction of sensory function of the dental pulp during preexfoliative stages. © International & American Associations for Dental Research 2015.

  4. Treatment of kraft paperboards and a kraft pulp with acrylonitrile

    Treesearch

    R. A. Horn; F. A. Simmonds

    1965-01-01

    Acrylonitrile (CH 2 = CH -CN) was reacted with unbleached southern pine kraft linerboard and bleached southern pine kraft cardstock to determine the effect of this treatment on compressive strength and dimensional stability. A sweetgum kraft pulp was treated similarly before and after bleaching and the paper-making qualities ,of the treated pulps were evaluated. The...

  5. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a...

  6. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a...

  7. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a...

  8. 21 CFR 872.1730 - Electrode gel for pulp testers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrode gel for pulp testers. 872.1730 Section 872.1730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...) Identification. An electrode gel for pulp testers is a device intended to be applied to the surface of a...

  9. Unusual Volar Pulp Location of Glomus Tumor

    PubMed Central

    Rosner, Ian A.; Argenta, Anne E.

    2017-01-01

    Summary: Glomus tumors are benign, painful growths originating from glomus bodies and comprise just 1% of tumors arising in the hand, with fewer than 10% in the volar pulp of digits. Hallmark symptoms of glomus tumors include hypersensitivity to cold, heightened pinprick sensitivity, and paroxysmal pain. We report a 72-year-old, right-hand dominant man who presented with pain in the left middle finger, localized to the tip. The fingertip was incredibly sensitive to touch, and his pain increased at night. He reported no recollection of trauma. Palpation of the finger revealed no mass, although it did indicate a focal point of pain within the distal pulp of the digit. Magnetic resonance imaging of the left hand revealed a round 7.0 × 4.0 × 6.0-mm soft tissue lesion along the volar ulnar aspect of the distal third digit. An incision was made in the mid-axial plane, circumscribing and removing the mass bluntly. It was a tan-yellow, soft tissue nodule of 0.8-cm in diameter without stalk or adherences to joints. Pathology revealed the mass was a glomus tumor. Symptoms improved on removal, and he healed without complication. Glomus tumors in the volar digital pulp can be difficult to diagnose. However, the presence of localized pain in the fingertip was reason to consider glomus tumor and proceed with treatment. Complete surgical removal of a glomus tumor is necessary to resolve symptoms and prevent recurrence. PMID:28203512

  10. Kinetic model for kraft pulping of hardwood

    SciTech Connect

    Giudici, R.; Park, S.W.

    1996-03-01

    A comprehensive model for the kraft pulping kinetics of Eucalyptus saligna hardwood is presented. Kinetic parameters were estimated by fitting the model to available experimental data taken from the literature over a range of process variables. The model takes into account the effect of hydroxide and sulfide concentration in the liquor as well as the temperature-time history of the cooking. Model predictions were successfully compared with an independent set of bench-scale plant data for lignin and carbohydrate dissolution. The model is able to predict quite well the trends of the process variables.

  11. Biodentine pulpotomy several days after pulp exposure: Four case reports

    PubMed Central

    Borkar, Swati A.; Ataide, Ida

    2015-01-01

    Conventionally, few-days-old pulp exposures have been treated with root canal treatment. We report four cases of traumatized, fully matured, maxillary permanent central incisors, which have been treated by Biodentine pulpotomy several days after traumatic pulp exposure. Biodentine pulpotomy consisted of pulp tissue removal to a depth of 2 mm, then capping the pulpal wound with Biodentine, followed by immediate restoration. The teeth were assessed clinically through pulpal sensitivity tests and radiographically for periapical healing. At each recall (24 hours, 1 week, 30 days, 3, 6, 12, and 18 months), no spontaneous pain was observed; the pulp showed signs of vitality and absence of periapical radiolucency after 18 months. Biodentine pulpotomy is recommended as a treatment option for cases of vital pulp exposure in permanent incisors due to trauma. PMID:25657533

  12. Lignin oxidation and pulp delignification by laccase and mediators

    SciTech Connect

    Bourbonnais, R.; Paice, M.G.; Reid, I.D.

    1996-10-01

    The phenol oxidizing enzyme laccase is produced abundantly by the lignin-degrading fungus Trametes versicolor. We found previously that laccase can oxidize veratryl alcohol and other non-phenolic lignin model compounds when a mediator such as 2,2{prime}-azinobis(3-ethylbenzthiazoline-5-sulphonate) (ABTS) was present. The laccase/mediator couple was also shown to be effective for delignification of kraft pulps. Two different isozymes of laccase produced by this fungus were purified and their reactivities towards lignins and kraft pulps were studied. The mediator ABTS was shown to be essential for pulp delignification and to reverse the polymerization of kraft lignin by either laccase. Pulp delignification with laccase and ABTS was also optimized. resulting in up to 55% lignin removal from kraft pulp following sequential enzyme treatments and alkaline extractions. Several variables were surveyed including enzyme and mediator dosage, oxygen pressure, temperature, reaction time, and pH.

  13. Nemesia Root Hair Response to Paper Pulp Substrate for Micropropagation

    PubMed Central

    Labrousse, Pascal; Delmail, David; Decou, Raphaël; Carlué, Michel; Lhernould, Sabine; Krausz, Pierre

    2012-01-01

    Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp. PMID:22312323

  14. Biodentine pulpotomy several days after pulp exposure: Four case reports.

    PubMed

    Borkar, Swati A; Ataide, Ida

    2015-01-01

    Conventionally, few-days-old pulp exposures have been treated with root canal treatment. We report four cases of traumatized, fully matured, maxillary permanent central incisors, which have been treated by Biodentine pulpotomy several days after traumatic pulp exposure. Biodentine pulpotomy consisted of pulp tissue removal to a depth of 2 mm, then capping the pulpal wound with Biodentine, followed by immediate restoration. The teeth were assessed clinically through pulpal sensitivity tests and radiographically for periapical healing. At each recall (24 hours, 1 week, 30 days, 3, 6, 12, and 18 months), no spontaneous pain was observed; the pulp showed signs of vitality and absence of periapical radiolucency after 18 months. Biodentine pulpotomy is recommended as a treatment option for cases of vital pulp exposure in permanent incisors due to trauma.

  15. Bioactive Phenylpropanoids, Phenolic Acid and Phytosterol from Landolphia owariensis P. Beauv Stringy Seed Pulp.

    PubMed

    Okonkwo, Tochukwu J N; Osadebe, Patience O; Proksch, Peter

    2016-01-01

    Landolphia owariensis P. Beauv is economically important for latex/rubber and folklore medicine. Its stringy seed pulp is freely eaten by humans and animals. Thus, L. owariensis stringy seed pulp was extracted serially with hexane and acetone to isolate and characterize its active pharmaceutical ingredients. Solvent/solvent partition and chromatographic separations afforded four bioactive compounds, (E)-3-(3,4-Dihydroxylcinnamoyl)quinic acid [(E)-Chlorogenic acid], I; (E)-3-(3,4-Dihydroxylcinnamoyl)quinic acid methyl ester [(E)-Chlorogenic acid methyl ester], II; 3,4-Dihydroxylbenzoic acid, (Protocatechuic acid), III; and 22,23-Dihydrostigmaster-3β-ol (3β-Sitosterol) (IV). Structures of I, II and III were assigned by combinations of high-performance liquid chromatography-ultraviolet-visible spectroscopy, 1D and 2D nuclear magnetic resonance spectroscopy, high-performance liquid chromatography-mass spectrometry and reference to published literatures, while compound IV was identified by chemical methods and gas chromatography-mass spectrometry. The phenylpropanoids and phenolic acid (compounds I, II and III) are notable standard antioxidants with confirmed hepatic-protective activity and other exciting biological activities. Compound IV has been reported to possess anti-inflammatory activity, anti-colon cancer action and a cholesterol-lowering effect. The described compounds are important medicinal constituents of L. owariensis stringy seed pulp, and this is the first major report on the phytochemistry of L. owariensis P. Beauv. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Economic evaluation of alternative wastewater treatment plant options for pulp and paper industry.

    PubMed

    Buyukkamaci, Nurdan; Koken, Emre

    2010-11-15

    Excessive water consumption in pulp and paper industry results in high amount of wastewater. Pollutant characteristics of the wastewater vary depending on the processes used in production and the quality of paper produced. However, in general, high organic material and suspended solid contents are considered as major pollutants of pulp and paper industry effluents. The major pollutant characteristics of pulp and paper industry effluents in Turkey were surveyed and means of major pollutant concentrations, which were grouped in three different pollution grades (low, moderate and high strength effluents), and flow rates within 3000 to 10,000m(3)/day range with 1000m(3)/day steps were used as design parameters. Ninety-six treatment plants were designed using twelve flow schemes which were combinations of physical treatment, chemical treatment, aerobic and anaerobic biological processes. Detailed comparative cost analysis which includes investment, operation, maintenance and rehabilitation costs was prepared to determine optimum treatment processes for each pollution grade. The most economic and technically optimal treatment processes were found as extended aeration activated sludge process for low strength effluents, extended aeration activated sludge process or UASB followed by an aeration basin for medium strength effluents, and UASB followed by an aeration basin or UASB followed by the conventional activated sludge process for high strength effluents.

  17. Anaerobic degradation of adsorbable organic halides (AOX) from pulp and paper industry wastewater.

    PubMed

    Savant, D V; Abdul-Rahman, R; Ranade, D R

    2006-06-01

    Adsorbable organic halides (AOX) are generated in the pulp and paper industry during the bleaching process. These compounds are formed as a result of reaction between residual lignin from wood fibres and chlorine/chlorine compounds used for bleaching. Many of these compounds are recalcitrant and have long half-life periods. Some of them show a tendency to bioaccumulate while some are proven carcinogens and mutagens. Hence, it is necessary to remove or degrade these compounds from wastewater. Physical, chemical and electrochemical methods reported to remove AOX compounds are not economically viable. Different types of aerobic, anaerobic and combined biological treatment processes have been developed for treatment of pulp and paper industry wastewater. Maximum dechlorination is found to occur under anaerobic conditions. However, as these processes are designed specifically for reducing COD and BOD of wastewater, they do not ensure complete removal of AOX. This paper reviews the anaerobic biological treatments developed for pulp and paper industry wastewater and also reviews the specific micro-organisms reported to degrade AOX compounds under anaerobic conditions, their nutritional and biochemical requirements. It is imperative to consider these specific micro-organisms while designing an anaerobic treatment for efficient removal of AOX.

  18. The Relationship between Organic Loading and Effects on Fish Reproduction for Pulp Mill Effluents across Canada.

    PubMed

    Martel, Pierre H; O'Connor, Brian I; Kovacs, Tibor G; van den Heuvel, Michael R; Parrott, Joanne L; McMaster, Mark E; MacLatchy, Deborah L; Van Der Kraak, Glen J; Hewitt, L Mark

    2017-03-09

    This study builds upon the work of a multiagency consortium tasked with determining cost-effective solutions for the effects of pulp mill effluents on fish reproduction. A laboratory fathead minnow egg production test and chemical characterization tools were used to benchmark 81 effluents from 20 mills across Canada, representing the major pulping, bleaching, and effluent treatment technologies. For Kraft and mechanical pulp mills, effluents containing less than 20 mg/L BOD5 were found to have the greatest probability of having no effects. Organic loading, expressed as the total detected solvent-extractable components by gas chromatography/mass spectrometry (GC/MS), also correlated with decreased egg laying. Exceptions were found for specific Kraft, mechanical, and sulfite mills, suggesting yet unidentified causative agents are involved. Recycled fiber mill effluents, tested for the first time, were found to have little potential for reproductive effects despite large variations in BOD5 and GC/MS profiles. Effluent treatment systems across all production types were generally efficient, achieving a combined 82-98% BOD5 removal. Further reductions of final effluent organic loadings toward the target of less than 20 mg/L are recommended and can be realized through biotreatment optimization, the reduction of organic losses associated with production upsets and selecting best available technologies that reduce organic loadings to biotreatment.

  19. Biological activity of bleached kraft pulp mill effluents before and after activated sludge and ozone treatments.

    PubMed

    Lopes, Alessandra Cunha; Mounteer, Ann H; Stoppa, Teynha Valverde; Aquino, Davi Santiago

    2013-01-01

    Eucalyptus bleached kraft pulp production, an important sector of the Brazilian national economy, is responsible for generating large volume, high pollutant load effluents, containing a considerable fraction of recalcitrant organic matter. The objectives of this study were to quantify the biological activity of the effluent from a eucalyptus bleached kraft pulp mill, characterize the nature of compounds responsible for biological activity and assess the effect of ozone treatment on its removal. Primary and secondary effluents were collected bimonthly over the course of one year at a Brazilian bleached eucalypt kraft pulp mill and their pollutant loads (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), adsorbable organic halogen (AOX), lignin, extractives) and biological activity (acute and chronic toxicity and estrogenic activity) quantified. The effluent studied did not present acute toxicity to Daphnia, but presented the chronic toxicity effects of algal growth inhibition and reduced survival and reproduction in Ceriodaphnia, as well as estrogenic activity. Chronic toxicity and estrogenic activity were reduced but not eliminated during activated sludge biological treatment. The toxicity identification evaluation revealed that lipophilic organic compounds (such as residual lignin, extractives and their byproducts) were responsible for the toxicity and estrogenic activity. Ozone treatment (50 mg/L O(3)) of the secondary effluent eliminated the chronic toxicity and significantly reduced estrogen activity.

  20. Pretreatment of pulp mill secondary sludge for high-rate anaerobic conversion to biogas.

    PubMed

    Wood, Nicholas; Tran, Honghi; Master, Emma

    2009-12-01

    Three pretreatment methods were compared based on their ability to increase the extent and rate of anaerobic bioconversion of pulp mill secondary sludge to biogas. The pretreatment technologies used in these experiments were: (i) thermal pretreatment performed at 170 degrees C; (ii) thermochemical (caustic) pretreatment performed at pH 12 and 140 degrees C; and (iii) sonication performed at 20 kHz and 1 W mL(-1). Sludge samples were obtained from a sulfite and a kraft pulp mill, and biochemical methane potential (BMP) assays were performed using microbial granules obtained from a high-rate anaerobic digester operating at a pulp mill. Biogas production from untreated sludge was 0.05 mL mg(-1) of measured chemical oxygen demand (COD) and 0.20 mL mg(-1) COD for kraft and sulfite sludge, respectively. Thermal pretreatment had the highest impact on sludge biodegradability. In this case, biogas yield and production rate from sulfite sludge increased by 50% and 10 times, respectively, while biogas yield and production rate from kraft sludge increased by 280% and 300 times, respectively. Biogas yield correlated to soluble carbohydrate content better than soluble COD.

  1. Regional bond strengths of adhesive resins to pulp chamber dentin.

    PubMed

    Belli, S; Zhang, Y; Pereira, P N; Ozer, F; Pashley, D H

    2001-08-01

    Microleakage of oral microorganisms, which can occur due to the lack of sealing ability of permanent restorative materials, may cause failure of root canal treatments. Although a great deal of research has been done on sealing enamel and coronal dentin with resins, little research has been done on the adhesion of resins to the walls of pulp chambers. The purpose of this study was to evaluate regional bond strengths of two adhesive systems to the walls of pulp chambers. A section was made horizontally through the middle of the pulp chamber of extracted human third molars to divide the chamber into upper and lower halves. The pulp tissue was removed and the tooth segments were then divided into treatment subgroups. The pulp chambers were bonded with C&B Metabond (Parkell) or One-Step (Bisco), with or without 5% NaOCI pretreatment. The microtensile bond strengths of these resins to four different pulp chamber regions (bottom, wall, roof, and pulp horn areas) were then measured using an Instron machine. The data were expressed in MPa and were analyzed by a three-way ANOVA. Statistically significant differences were found among the test groups (p < 0.001). One-Step produced higher bond strengths to all pulp chamber regions except the floor, compared with C&B Metabond. The results indicated that high bond strengths can be achieved between adhesive resins and the various regions of the pulp chamber. This should permit the use of a thick layer of unfilled resin along the floor of the pulp chamber and over the canal orifices as a secondary protective seal after finishing root canal therapy.

  2. The influence of pulping and washing conditions on the properties of Eucalyptus grandis unbleached kraft pulps treated with chelants.

    PubMed

    Area, M C; Carvalho, M G V S; Ferreira, P J; Felissia, F E; Barboza, O M; Bengoechea, D I

    2010-03-01

    The influence of different addition points of a chelating agent and a counter-ion exchange on the properties of Eucalyptus grandis unbleached kraft pulps is studied. Seven pulps were considered: two laboratory kraft pulps with or without the inclusion of the chelant DTPMPA (diethylene triamine penta (methylene phosphonic acid)), a mill kraft pulp and four mill pulps after Ca(+2) or Na(+) counter-ion exchange followed, or not, by washing with DTPMPA addition. The laboratory pulps required lower beating energy than the industrial pulps for achieving 30 degrees SR, and the corresponding handsheets also showed better strength and optical properties, as well as a more homogeneous and smooth surface. The counter-ion exchange decreases the mechanical resistances and increases brightness. However, the effects of Ca(+2) are deeper than those of Na(+). DTPMPA added to pulping causes a decrease in calcium content whereas as a washing additive does not have a relevant impact on the mechanical and optical properties. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  3. Alkaline polyol pulping and enzymatic hydrolysis of hardwood: effect of pulping severity and pulp composition on cellulase activity and overall sugar yield.

    PubMed

    Hundt, Martin; Schnitzlein, Klaus; Schnitzlein, Michael G

    2013-05-01

    The saccharification of beech wood using alkaline polyol pulping (AlkaPolP) and enzymatic hydrolysis was investigated. It will be demonstrated that the AlkaPolP process yields high quality pulps which can easily be hydrolyzed by cellulases. In order to find optimum reaction conditions chips of Fagus sylvatica were pretreated by alkaline glycerol at temperatures between 190 and 230 °C for 15, 20, and 25 min. The impacts of temperature and time were expressed using a severity factor R0. The dependencies of the conversion during enzymatic hydrolysis on severity, pulp yield, delignification and pulp composition are shown. In further experiments it was investigated if the sugar yields can be increased by the application of ultrasound or surfactants before enzyme addition. Up to 95% of the initial cellulose in wood were converted into glucose using cellulases from Trichoderma reesei and β-glucosidase from Aspergillus niger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Evaluation of lignins from side-streams generated in an olive tree pruning-based biorefinery: Bioethanol production and alkaline pulping.

    PubMed

    Santos, José I; Fillat, Úrsula; Martín-Sampedro, Raquel; Eugenio, María E; Negro, María J; Ballesteros, Ignacio; Rodríguez, Alejandro; Ibarra, David

    2017-07-06

    In modern lignocellulosic-based biorefineries, carbohydrates can be transformed into biofuels and pulp and paper, whereas lignin is burned to obtain energy. However, a part of lignin could be converted into value-added products including bio-based aromatic chemicals, as well as building blocks for materials. Then, a good knowledge of lignin is necessary to define its valorisation procedure. This study characterized different lignins from side-streams produced from olive tree pruning bioethanol production (lignins collected from steam explosion pretreatment with water or phosphoric acid as catalysts, followed by simultaneous saccharification and fermentation process) and alkaline pulping (lignins recovered from kraft and soda-AQ black liquors). Together with the chemical composition, the structure of lignins was investigated by FTIR, (13)C NMR, and 2D NMR. Bioethanol lignins had clearly distinct characteristics compared to pulping lignins; a certain number of side-chain linkages (mostly alkyl-aryl ether and resinol) accompanied with lower phenolic hydroxyls content. Bioethanol lignins also showed a significant amount of carbohydrates, mainly glucose and protein impurities. By contrast, pulping lignins revealed xylose together with a dramatical reduction of side-chains (some resinol linkages survive) and thereby higher phenol content, indicating rather severe lignin degradation during alkaline pulping processes. All lignins showed a predominance of syringyl units. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Antioxidant properties of various solvent extracts of potato peel, sugar beet pulp and sesame cake.

    PubMed

    Mohdaly, Adel A A; Sarhan, Mohamed A; Smetanska, Iryna; Mahmoud, Awad

    2010-01-30

    Growing interest in the replacement of synthetic food antioxidants by natural ones has fostered research on vegetable sources and screening of raw materials to identify new antioxidants. The food-processing industry generates substantial quantities of phenolic-rich by-products that could be valuable natural sources of antioxidants. In this study the antioxidant properties and total phenolic, flavonoid and flavonol contents of three industrial by-products, sugar beet pulp, sesame cake and potato peel, extracted with various solvents were examined. Since different antioxidant compounds have different mechanisms of action, several methods were used to assess the antioxidant efficacy of extracts. Among the six solvents tested, methanol gave the highest extract yield of potato peel and sugar beet pulp, while diethyl ether gave the highest extract yield of sesame cake. Methanol exhibited the highest extraction ability for phenolic compounds, with total phenolics amounting to 2.91, 1.79 and 0.81 mg gallic acid equivalent g(-1) dry weight in potato peel, sugar beet pulp and sesame cake extracts respectively, and also showed the strongest antioxidant capacity in the three assays used. All three methods proved that potato peel extract had the highest antioxidant activity owing to its high content of phenolic compounds and flavonoids. On the basis of the results obtained, potato peel, sugar beet pulp and sesame cake extracts could serve as natural antioxidants owing to their significant antioxidant activity. Therefore they could be used as preservative ingredients in the food and/or pharmaceutical industries. (c) 2009 Society of Chemical Industry.

  6. Effect of IRM on human dental pulp.

    PubMed

    Möller, B; Schröder, U; Granath, L

    1983-08-01

    IRM has been shown to be superior to conventional ZnOE cements. This study is a biotechnical investigation of IRM's effect on the dental pulp with respect to its sealing capacity. Enamel-dentin test bodies with IRM fillings were used in the in vitro part, where insufficiencies in sealing were detected with compressed air. The in vivo part included 44 buccal cavities in intact premolars. In teeth in which the material effect of IRM was tested, the IRM fillings were sealed off from the saliva by acid etch and composite resin. The observation intervals were 1, 7 and 28 days. Histologic changes such as capillary dilatations and presence of inflammatory cells in the pulp adjacent to the dentinal tubules involved in the cavity preparation were registered. The in vitro test showed no leakage in five cases out of six. After extreme temperature cycling, the leakage was comparable with that of zinc-containing amalgam of traditional alloy. The pulpal changes were mild and mainly ascribed to the material effect of IRM, since no evidence was found of leakage of biologic importance.

  7. Adhesive sealing of the pulp chamber.

    PubMed

    Belli, S; Zhang, Y; Pereira, P N; Pashley, D H

    2001-08-01

    The purpose of this in vitro study was to evaluate quantitatively the ability of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar teeth were used. The top of pulp chambers and distal halves of the roots were removed using an Isomet saw. The canal orifices were temporarily sealed with a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a wet bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydride adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid filtration method was used for quantitative evaluation of leakage. Measurements of fluid movement were made at 2-min intervals for 8 min. The quality of the seal of each specimen was measured by fluid filtration immediately and after 1 day, 1 wk, and 1 month. Even after 1 month the resins showed an excellent seal. Zinc oxide-eugenol had significantly more leakage when compared with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.

  8. A Novel Combinatorial Therapy With Pulp Stem Cells and Granulocyte Colony-Stimulating Factor for Total Pulp Regeneration

    PubMed Central

    Iohara, Koichiro; Murakami, Masashi; Takeuchi, Norio; Osako, Yohei; Ito, Masataka; Ishizaka, Ryo; Utunomiya, Shinji; Nakamura, Hiroshi; Matsushita, Kenji

    2013-01-01

    Treatment of deep caries with pulpitis is a major challenge in dentistry. Stem cell therapy represents a potential strategy to regenerate the dentin-pulp complex, enabling conservation and restoration of teeth. The objective of this study was to assess the efficacy and safety of pulp stem cell transplantation as a prelude for the impending clinical trials. Clinical-grade pulp stem cells were isolated and expanded according to good manufacturing practice conditions. The absence of contamination, abnormalities/aberrations in karyotype, and tumor formation after transplantation in an immunodeficient mouse ensured excellent quality control. After autologous transplantation of pulp stem cells with granulocyte-colony stimulating factor (G-CSF) in a dog pulpectomized tooth, regenerated pulp tissue including vasculature and innervation completely filled in the root canal, and regenerated dentin was formed in the coronal part and prevented microleakage up to day 180. Transplantation of pulp stem cells with G-CSF yielded a significantly larger amount of regenerated dentin-pulp complex compared with transplantation of G-CSF or stem cells alone. Also noteworthy was the reduction in the number of inflammatory cells and apoptotic cells and the significant increase in neurite outgrowth compared with results without G-CSF. The transplanted stem cells expressed angiogenic/neurotrophic factors. It is significant that G-CSF together with conditioned medium of pulp stem cells stimulated cell migration and neurite outgrowth, prevented cell death, and promoted immunosuppression in vitro. Furthermore, there was no evidence of toxicity or adverse events. In conclusion, the combinatorial trophic effects of pulp stem cells and G-CSF are of immediate utility for pulp/dentin regeneration, demonstrating the prerequisites of safety and efficacy critical for clinical applications. PMID:23761108

  9. On the importance of hydroquinone/p-quinone redox system in the photoyellowing of mechanical pulps

    Treesearch

    Umesh P. Agarwal

    1999-01-01

    In the area of photoyellowing of mechanical pulps, recently obtained experimental evidence has shown that hydroquinone/p-quinone redox couple is present in lignin-rich mechanical pulps. It was also noted that compared to a control pulp the concentration of p-quinones was significantly higher in a photoyellowed pulp. Under ambient conditions, upon exposure to light, the...

  10. Evaluation of blown down Alaska spruce and hemlock trees for pulp.

    Treesearch

    Donald J. Fahey; James M. Cahill

    1983-01-01

    Chips from Alaska hemlock and spruce trees blown down more than 10 years produced usable grades of viscose pulp. Yields of pulp from both species were about 2 percent lower for blowdown material than for control trees. Ash content was slightly higher in the pulp manufactured from blowdown timber than in pulp from control trees.

  11. Cancer risk associated with pulp and paper mills: a review of occupational and community epidemiology.

    PubMed

    Soskolne, Colin L; Sieswerda, Lee E

    2010-01-01

    Pulp and paper mills use a variety of chemical substances potentially hazardous to human health. Compounds of both short- and long-term toxicological significance are found in workplaces, air emissions, and water effluent. In this paper we evaluate the body of published literature on cancer associated with working in pulp and paper mills as well as in surrounding communities. Multiple comparisons, questionable statistical power, and the absence of individual exposure assessments have resulted in non-corroborative findings over the years. However, a new generation of study sophistication, international in scale and coordinated by the International Agency for Research on Cancer (IARC), has catalogued tens of thousands of exposure measurements made at a large number of work stations within the pulp and paper industry, allowing for greatly improved individual-level exposure assessments. This approach reduces non-differential misclassification of exposure, increasing the power of these studies to detect exposure disease relationships, especially for rarer cancers. While the ability to associate specific chemical exposures with cancer outcomes in the large IARC multinational cohort may yet help to resolve the status of some of the many chemicals not currently classifiable as to their carcinogenicity by IARC, this effort has, to date, not added significantly to knowledge. Of the three studies they have published to date, one involved a well-established carcinogen (asbestos) and another involved a mixture containing probable carcinogens (volatile organochlorines). While the asbestos study is somewhat unremarkable for finding an association with pleural cancer in the expected direction, the volatile organochlorine study may be most notable for failing to find an association between volatile organochlorine exposure and liver cancer, non-Hodgkin's lymphoma, or esophageal cancer, as some previous studies had found. Nonetheless, given the known hazards and the potential for

  12. Antioxidant and Carbohydrate-Hydrolysing Enzymes Potential of Sechium edule (Jacq.) Swartz (Cucurbitaceae) Peel, Leaves and Pulp Fresh and Processed.

    PubMed

    Loizzo, Monica Rosa; Bonesi, Marco; Menichini, Francesco; Tenuta, Maria Concetta; Leporini, Mariarosaria; Tundis, Rosa

    2016-12-01

    Sechum edule peel, leaves and pulp were investigated for their chemical composition (total phenol, flavonoid, carotenoid and vitamin C content), and for antioxidant activity and carbohydrate-hydrolysing enzymes (α-amylase and α-glucosidase) inhibition. In order to evaluate the incidence of cooking process on retention of healthy phytochemicals, the pulp was subjected to different treatments (grill roasting, domestic oven baking, microwave cooking, blanching and steaming). Cooking processes reduced the total phenol content (58.5 mg/g extract for fresh pulp vs 26.3 and 29.3 mg/g extract for roasted and steamed samples, respectively). Pulp was found to be the most active in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) (IC50 of 0.1 mg/mL), whereas peel showed the highest activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) test (IC50 of 0.4 mg/mL). Moreover, peel exhibited the highest inhibitory activity against α-amylase with an IC50 of 0.2 mg/mL, except for steamed cooking process, which drastically influenced the bioactivity against both enzymes.

  13. High-solids black liquor firing in pulp and paper industry Kraft recovery boilers. Final report, Phase 1, Volume 1: Executive summary

    SciTech Connect

    Southards, W.T.; Clement, J.L.; McIlroy, R.A.; Tharp, M.R.; Verrill, C.L.; Wessell, R.A.

    1995-11-01

    This project is a multiple-phase effort to develop technologies to improve high-solids black liquor firing in pulp mill recovery boilers. The objectives are to develop a preliminary design of a recovery furnace simulator; evaluate the economics of high-solids; and delineate a project concept for evaluating candidate technologies to improve chemical recovery.

  14. Scaffolds to control inflammation and facilitate dental pulp regeneration.

    PubMed

    Colombo, John S; Moore, Amanda N; Hartgerink, Jeffrey D; D'Souza, Rena N

    2014-04-01

    In dentistry, the maintenance of a vital dental pulp is of paramount importance because teeth devitalized by root canal treatment may become more brittle and prone to structural failure over time. Advanced carious lesions can irreversibly damage the dental pulp by propagating a sustained inflammatory response throughout the tissue. Although the inflammatory response initially drives tissue repair, sustained inflammation has an enormously destructive effect on the vital pulp, eventually leading to total necrosis of the tissue and necessitating its removal. The implications of tooth devitalization have driven significant interest in the development of bioactive materials that facilitate the regeneration of damaged pulp tissues by harnessing the capacity of the dental pulp for self-repair. In considering the process by which pulpitis drives tissue destruction, it is clear that an important step in supporting the regeneration of pulpal tissues is the attenuation of inflammation. Macrophages, key mediators of the immune response, may play a critical role in the resolution of pulpitis because of their ability to switch to a proresolution phenotype. This process can be driven by the resolvins, a family of molecules derived from fatty acids that show great promise as therapeutic agents. In this review, we outline the importance of preserving the capacity of the dental pulp to self-repair through the rapid attenuation of inflammation. Potential treatment modalities, such as shifting macrophages to a proresolving phenotype with resolvins are described, and a range of materials known to support the regeneration of dental pulp are presented.

  15. Wood pulp characterization by a novel photoacoustic sensor

    NASA Astrophysics Data System (ADS)

    Niemi, Jan; Löfqvist, Torbjörn

    2012-08-01

    In this paper we introduce a novel photoacoustic sensing technique that captures a photoacoustic signal excited by a laser light pulse after the light has propagated through a turbid medium. Simultaneously, the ultrasonic sound wave is captured after it has propagated through the same turbid medium. By combining the two signals, more information on the investigated medium can be obtained. Applications can be found in the pulp and paper industry where monitoring wood pulp compositions is of interest. Depending on its origin, pulp suspension contains different compositions of fibres and fibre fragments (fines). Poor control of the pulp composition leads to an unstable process that compromises the production, quality and energy efficiency in the pulp mill. The result shows the feasibility of the photoacoustic sensor in monitoring the mass fractions of fibres and fines in a pulp suspension. The first received echo, corresponding to the light interaction with the sample, showed a stronger correlation to the fines mass fraction compared to fibre mass fraction. The second echo, corresponding to the sound wave interaction with the sample, showed a much stronger correlation to fibre mass fraction than to fines mass fraction. Hence, it is proposed that by combining these two echoes, more information about the pulp suspension could be extracted than from any other sensor built on a single sensing principle.

  16. Ozone delignification of pine and eucalyptus kraft pulps. 2: Selectivity

    SciTech Connect

    Simoes, R.M.S.; Castro, J.A.A.M.

    1999-12-01

    The selectivity of ozone in the delignification of unbleached pine and eucalyptus kraft pulps is studied at ultralow consistency in a stirred reactor under closely controlled experimental conditions. The effect of several operating variables is analyzed, but special attention is paid to the depolymerization rate of polysaccharides with the particular goal of evaluating the influence of the lignin contents on its kinetics. By using substantially different ozone concentrations in the pulp suspension and different reaction temperatures, it is possible to show that ozone selectivity can only be slightly improved by manipulating these operating variables. Furthermore, for the same type of material, it was observed that the initial rate of delignification plays the most important role on selectivity. In fact, for a given pulp, selectivity decreases with a decrease of the initial lignin contents, and such results can be well justified by the corresponding reduction of the initial rates of delignification. To further investigate the effect of lignin on pulp degradation, experiments were carried out at 4 C between ozone and holocellulose, which represent the polysaccharides of the unbleached pulps. The results suggest that molecular ozone can be responsible for an important part of the polysaccharides depolymerization during the delignification process. Moreover, the comparison of the kinetic behavior of holocellulose and of the corresponding unbleached pulp also reveals that the presence of lignin in the pulp enhances both the depolymerization and the degradation rates of polysaccharides.

  17. Microbial Factors and Antimicrobial Strategies in Dental Pulp Regeneration.

    PubMed

    Fouad, Ashraf F

    2017-09-01

    Dental pulp regeneration after pulp necrosis in immature teeth represents a major departure from traditional endodontic therapy of these conditions. Preliminary clinical attempts have shown the feasibility of developing mineralized repair tissue, which may provide a clinically acceptable outcome. However, this outcome may not provide sufficient host response and root strength to ensure the longevity of the involved teeth. It is not clear if these preliminary suboptimal results are caused by the inability to fully disinfect the pulp space or the absence of a suitable progenitor cell/scaffold template together with adequate vascularity. Moreover, it is not known to what degree the root canal system needs to be disinfected in order for clinical success to be evident. This article describes the current clinical strategies and protocols for the optimal disinfection and preparation of the pulp space environment to promote periapical healing as well as soft and hard tissue development after an infectious process. Current and future strategies for disinfecting the pulp space with minimal disruption of the necessary biological factors from dentin, the progenitor cells in periapical vital tissues, and the vascularity are discussed. The potential for success of pulp regeneration after necrosis and infection would transform the practice of endodontics, even for mature teeth. This is a goal worth pursuing because it would achieve the restoration of normal host responses in the pulp space and the regeneration of destroyed dental tissues. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Scaffolds to Control Inflammation and Facilitate Dental Pulp Regeneration

    PubMed Central

    Colombo, John S.; Moore, Amanda N.; Hartgerink, Jeffrey D.; D’Souza, Rena N.

    2014-01-01

    In dentistry, the maintenance of a vital dental pulp is of paramount importance, as teeth devitalized by root canal treatment may become more brittle and prone to structural failure over time. Advanced carious lesions can irreversibly damage the dental pulp by propagating a sustained inflammatory response throughout the tissue. While the inflammatory response initially drives tissue repair, sustained inflammation has an enormously destructive effect on the vital pulp, eventually leading to total necrosis of the tissue and necessitating its removal. The implications of tooth devitalization have driven significant interest in the development of bioactive materials that facilitate the regeneration of damaged pulp tissues by harnessing the capacity of the dental pulp for self-repair. In considering the process by which pulpitis drives tissue destruction, it is clear that an important step in supporting the regeneration of pulpal tissues is the attenuation of inflammation. Macrophages, key mediators of the immune response, may play a critical role in the resolution of pulpitis due to their ability to switch to a pro-resolution phenotype. This process can be driven by the resolvins, a family of molecules derived from fatty acids that show great promise as therapeutic agents. In this review, we outline the importance of preserving the capacity of the dental pulp to self-repair through the rapid attenuation of inflammation. Potential treatment modalities, such as shifting macrophages to a pro-resolving phenotype with resolvins are described, and a range of materials known to support the regeneration of dental pulp are presented. PMID:24698696

  19. Dental Pulp Defence and Repair Mechanisms in Dental Caries.

    PubMed

    Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J; Cooper, Paul R

    2015-01-01

    Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo.

  20. Dental Pulp Defence and Repair Mechanisms in Dental Caries

    PubMed Central

    Farges, Jean-Christophe; Alliot-Licht, Brigitte; Renard, Emmanuelle; Ducret, Maxime; Gaudin, Alexis; Smith, Anthony J.; Cooper, Paul R.

    2015-01-01

    Dental caries is a chronic infectious disease resulting from the penetration of oral bacteria into the enamel and dentin. Microorganisms subsequently trigger inflammatory responses in the dental pulp. These events can lead to pulp healing if the infection is not too severe following the removal of diseased enamel and dentin tissues and clinical restoration of the tooth. However, chronic inflammation often persists in the pulp despite treatment, inducing permanent loss of normal tissue and reducing innate repair capacities. For complete tooth healing the formation of a reactionary/reparative dentin barrier to distance and protect the pulp from infectious agents and restorative materials is required. Clinical and in vitro experimental data clearly indicate that dentin barrier formation only occurs when pulp inflammation and infection are minimised, thus enabling reestablishment of tissue homeostasis and health. Therefore, promoting the resolution of pulp inflammation may provide a valuable therapeutic opportunity to ensure the sustainability of dental treatments. This paper focusses on key cellular and molecular mechanisms involved in pulp responses to bacteria and in the pulpal transition between caries-induced inflammation and dentinogenic-based repair. We report, using selected examples, different strategies potentially used by odontoblasts and specialized immune cells to combat dentin-invading bacteria in vivo. PMID:26538821

  1. Effect of Light Activation of Pulp-Capping Materials and Resin Composite on Dentin Deformation and the Pulp Temperature Change.

    PubMed

    Soares, C J; Ferreira, M S; Bicalho, A A; de Paula Rodrigues, M; Braga, Ssl; Versluis, A

    2017-10-04

    To analyze the effect of pulp-capping materials and resin composite light activation on strain and temperature development in the pulp and on the interfacial integrity at the pulpal floor/pulp-capping materials in large molar class II cavities. Forty extracted molars received large mesio-occlusal-distal (MOD) cavity bur preparation with 1.0 mm of dentin remaining at the pulp floor. Four pulp-capping materials (self-etching adhesive system, Clearfil SE Bond [CLE], Kuraray), two light-curing calcium hydroxide cements (BioCal [BIO], Biodinâmica, and Ultra-Blend Plus [ULT], Ultradent), and a resin-modified glass ionomer cement- (Vitrebond [VIT], 3M ESPE) were applied on the pulpal floor. The cavities were incrementally restored with resin composite (Filtek Z350 XT, 3M ESPE). Thermocouple (n=10) and strain gauge (n=10) were placed inside the pulp chamber in contact with the top of the pulpal floor to detect temperature changes and dentin strain during light curing of the pulp-capping materials and during resin composite restoration. Exotherm was calculated by subtracting postcure from polymerization temperature (n=10). Interface integrity at the pulpal floor was investigated using micro-CT (SkyScan 1272, Bruker). The degree of cure of capping materials was calculated using the Fourier transform infrared and attenuated total reflectance cell. Data were analyzed using one-way analysis of variance followed by the Tukey test (α=0.05). Pulpal dentin strains (μs) during light curing of CLE were higher than for other pulp-capping materials (p<0.001). During resin composite light activation, the pulpal dentin strain increased for ULT, VIT, and CLE and decreased for BIO. The pulpal dentin strain was significantly higher during pulp-capping light activation. The temperature inside the pulp chamber increased approximately 3.5°C after light curing the pulp-capping materials and approximately 2.1°C after final restoration. Pulp-capping material type had no influence temperature

  2. Yield Improvement and Energy Savings Uing Phosphonates as Additives in Kraft pulping

    SciTech Connect

    Ulrike W. Tschirner; Timothy Smith

    2007-03-31

    Project Objective: Develop a commercially viable modification to the Kraft process resulting in energy savings, increased yield and improved bleachability. Evaluate the feasibility of this technology across a spectrum of wood species used in North America. Develop detailed fundamental understanding of the mechanism by which phosphonates improve KAPPA number and yield. Evaluate the North American market potential for the use of phosphonates in the Kraft pulping process. Examine determinants of customer perceived value and explore organizational and operational factors influencing attitudes and behaviors. Provide an economic feasibility assessment for the supply chain, both suppliers (chemical supply companies) and buyers (Kraft mills). Provide background to most effectively transfer this new technology to commercial mills.

  3. Preparation of clinker from paper pulp industry wastes.

    PubMed

    Buruberri, Leire H; Seabra, M P; Labrincha, J A

    2015-04-09

    The production of paper pulp by the Kraft method generates considerable amounts of wastes. Namely, lime mud generated in the recovery circuit of chemical reagents, biological sludge from the wastewater treatment of wood digestion process and fly ash collected in the fluidized bed combustor used to generate electricity from biomass burning. The final destination of such wastes is an important concern, since environmental regulations are becoming stricter regarding their landfill. Driven by this fact, industries are looking for more sustainable solutions, such as the recycling in distinct products. This work tested these wastes as secondary raw materials to produce clinker/cement that was then experienced in mortar formulations. The first step involved the residues detailed characterization and a generated amounts survey. Then, specific but simple steps were suggested, aiming to facilitate transport and manipulation. Distinct blends were prepared and fired in order to get belitic and Portland clinkers. The Portland clinkers were processed at lower temperatures than the normally used in the industry due to the presence of mineralizing impurities in some wastes. Belite-based cements were used to produce mortars that developed satisfactory mechanical strength and did not reveal signs of deterioration or durability weaknesses.

  4. Food Value of Mealworm Grown on Acrocomia aculeata Pulp Flour

    PubMed Central

    Alves, Ariana Vieira; Sanjinez-Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insects have played an important role as human food throughout history, especially in Africa, Asia and Latin America. A good example of edible insects is the mealworm, Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae), which are eaten in Africa, Asia, the Americas and Australia. This species is easily bred in captivity, requiring simple management. The bocaiuva (Acrocomia aculeata (Jacq.) Lodd) is an abundant palm tree found in the Brazilian Cerrado, providing fruits with high nutritional value. The aim of this work was to determine the chemical composition of T. molitor grown in different artificial diets with bocaiuva pulp flour. The nutritional composition, fatty acid composition, antioxidant activity, trypsin activity and anti-nutritional factors of larvae were analyzed. The results showed that mealworms grown on artificial diet with bocaiuva are a good source of protein (44.83%) and lipid (40.45%), with significant levels of unsaturated fatty acids (65.99%), antioxidant activity (4.5 μM Trolox/g of oil extracted from larvae) and absence of anti-nutritional factors. This study indicates a new source of biomass for growing mealworms and shows that it is possible to breed mealworms in artificial diet with bocaiuva flour without compromising the nutritional quality of the larvae. PMID:26974840

  5. A novel lignin degradation bacterial consortium for efficient pulping.

    PubMed

    Wang, Yanxia; Liu, Quan; Yan, Lei; Gao, Yamei; Wang, Yanjie; Wang, Weidong

    2013-07-01

    A lignin degradation bacterial consortium named LDC was screened from the sludge of a reeds pond by a restricted subculture. It could break down 60.9% lignin in reeds at 30°C under conditions of static culture within 15 days. In order to analyze the diversity of LDC, plate isolation, 16S rDNA clone library and ARDRA (Amplified Ribosomal DNA Restriction Analysis) were performed. Six bacterial strains were isolated from LDC and eighteen DNA phylotypes were identified from 230 bacterial analyzed clones. They were classified into Clostridiales(9.1%), Geovibrio thiophilus (5.1%), Desulfomicrobium (10.9%), Pseudomonas sp. (25.2%), Azoarcus sp. (5.1%), Thauera (5.1%), Paenibacillus sp. (5.1%), Cohnella sp. (2.2%), Acinetobacter sp. (3.1%), Microbacterium (7.8%), and uncultured bacterium (21.3%). In addition, physical characteristics of paper hand-sheets between biological pretreatment and chemical pretreatment were compared. The results showed that LDC had the capability of lignin degradation and was efficient for pulping, which would provide a new choice for biopulping.

  6. Ash from a pulp mill boiler--characterisation and vitrification.

    PubMed

    Ribeiro, Ana S M; Monteiro, Regina C C; Davim, Erika J R; Fernandes, M Helena V

    2010-07-15

    The physical, chemical and mineralogical characterisation of the ash resulting from a pulp mill boiler was performed in order to investigate the valorisation of this waste material through the production of added-value glassy materials. The ash had a particle size distribution in the range 0.06-53 microm, and a high amount of SiO(2) (approximately 82 wt%), which was present as quartz. To favour the vitrification of the ash and to obtain a melt with an adequate viscosity to cast into a mould, different amounts of Na(2)O were added to act as fluxing agent. A batch with 80 wt% waste load melted at 1350 degrees C resulting in a homogeneous transparent green-coloured glass with good workability. The characterisation of the produced glass by differential thermal analysis and dilatometry showed that this glass presents a stable thermal behaviour. Standard leaching tests revealed that the concentration of heavy metals in the leaching solution was lower than those allowed by the Normative. As a conclusion, by vitrification of batch compositions with adequate waste load and additive content it is possible to produce an ash-based glass that may be used in similar applications as a conventional silicate glass inclusively as a building ecomaterial.

  7. Treatment of paper and pulp mill effluent by coagulation.

    PubMed

    Chaudhari, Parmesh Kumar; Majumdar, Bidyut; Choudhary, Rumi; Yadav, Deepak Kumar; Chand, Shri

    2010-04-01

    Pulp and paper mill effluent is highly polluting and is a subject of great environmental concern. In the present research we studied the removal of chemical oxygen demand (COD) and colour from paper mill effluent, using the coagulation process. A batch coagulation study was conducted using various coagulants such as aluminium chloride (AlCl3), polyaluminium chloride (PAC) and copper sulphate (CuSO4 x 5H20). The initial pH of the effluent had a tremendous effect on the COD and colour removal. The PAC reduced COD by 83% and reduced colour by 92% at an optimum pH of 5.0 and a coagulant dose of 8 mL L(-1). With AlCl3, at an optimum pH of 4.0 and a coagulant dose of 5 g L(-1), 72% COD removal and 84% colour removal were observed. At an optimum pH of 6.0 and a mass loading of 5 g L(-1), 76% COD reduction and 78% colour reduction were obtained with copper sulphate. It was also observed that, after addition of coagulant, the pH of the effluent decreased. The decrease in the pH was highest with AlCl3, followed by PAC and then CuSO4 x 5H20.

  8. Food Value of Mealworm Grown on Acrocomia aculeata Pulp Flour.

    PubMed

    Alves, Ariana Vieira; Sanjinez-Argandoña, Eliana Janet; Linzmeier, Adelita Maria; Cardoso, Claudia Andrea Lima; Macedo, Maria Lígia Rodrigues

    2016-01-01

    Insects have played an important role as human food throughout history, especially in Africa, Asia and Latin America. A good example of edible insects is the mealworm, Tenebrio molitor Linnaeus, 1758 (Coleoptera, Tenebrionidae), which are eaten in Africa, Asia, the Americas and Australia. This species is easily bred in captivity, requiring simple management. The bocaiuva (Acrocomia aculeata (Jacq.) Lodd) is an abundant palm tree found in the Brazilian Cerrado, providing fruits with high nutritional value. The aim of this work was to determine the chemical composition of T. molitor grown in different artificial diets with bocaiuva pulp flour. The nutritional composition, fatty acid composition, antioxidant activity, trypsin activity and anti-nutritional factors of larvae were analyzed. The results showed that mealworms grown on artificial diet with bocaiuva are a good source of protein (44.83%) and lipid (40.45%), with significant levels of unsaturated fatty acids (65.99%), antioxidant activity (4.5 μM Trolox/g of oil extracted from larvae) and absence of anti-nutritional factors. This study indicates a new source of biomass for growing mealworms and shows that it is possible to breed mealworms in artificial diet with bocaiuva flour without compromising the nutritional quality of the larvae.

  9. TOOTH (The Open study Of dental pulp stem cell Therapy in Humans): Study protocol for evaluating safety and feasibility of autologous human adult dental pulp stem cell therapy in patients with chronic disability after stroke.

    PubMed

    Nagpal, Anjali; Kremer, Karlea L; Hamilton-Bruce, Monica A; Kaidonis, Xenia; Milton, Austin G; Levi, Christopher; Shi, Songtao; Carey, Leeanne; Hillier, Susan; Rose, Miranda; Zacest, Andrew; Takhar, Parabjit; Koblar, Simon A

    2016-07-01

    Stroke represents a significant global disease burden. As of 2015, there is no chemical or biological therapy proven to actively enhance neurological recovery during the chronic phase post-stroke. Globally, cell-based therapy in stroke is at the stage of clinical translation and may improve neurological function through various mechanisms such as neural replacement, neuroprotection, angiogenesis, immuno-modulation, and neuroplasticity. Preclinical evidence in a rodent model of middle cerebral artery ischemic stroke as reported in four independent studies indicates improvement in neurobehavioral function with adult human dental pulp stem cell therapy. Human adult dental pulp stem cells present an exciting potential therapeutic option for improving post-stroke disability. TOOTH (The Open study Of dental pulp stem cell Therapy in Humans) will investigate the use of autologous stem cell therapy for stroke survivors with chronic disability, with the following objectives: (a) determine the maximum tolerable dose of autologous dental pulp stem cell therapy; (b) define that dental pulp stem cell therapy at the maximum tolerable dose is safe and feasible in chronic stroke; and (c) estimate the parameters of efficacy required to design a future Phase 2/3 clinical trial. TOOTH is a Phase 1, open-label, single-blinded clinical trial with a pragmatic design that comprises three stages: Stage 1 will involve the selection of 27 participants with middle cerebral artery ischemic stroke and the commencement of autologous dental pulp stem cell isolation, growth, and testing in sequential cohorts (n = 3). Stage 2 will involve the transplantation of dental pulp stem cell in each cohort of participants with an ascending dose and subsequent observation for a 6-month period for any dental pulp stem cell-related adverse events. Stage 3 will investigate the neurosurgical intervention of the maximum tolerable dose of autologous dental pulp stem cell followed by 9 weeks of intensive task

  10. Reducing sugar production of sweet sorghum bagasse kraft pulp

    NASA Astrophysics Data System (ADS)

    Solihat, Nissa Nurfajrin; Fajriutami, Triyani; Adi, Deddy Triyono Nugroho; Fatriasari, Widya; Hermiati, Euis

    2017-01-01

    Kraft pulping of sweet sorghum bagasse (SSB) has been used for effective delignification method for cellulose production. This study was conducted to evaluate the performance pulp kraft of SSB for reducing sugar production. The study intended to investigate the effect of active alkali and sulfidity loading variation of SSB pulp kraft on reducing sugar yield per biomass. The SSB pulp was prepared after pulping using three variations of active alkali (17, 19, and 22%) and sulfidity loading (20, 22, and 24%) at 170°C for 4 h with liquor to wood ratio of 10. A total of 9 pulps were obtained from these pretreatments. Delignification pretreatment has been succesfully removed lignin and hemicellulose more than 90% and 50%, respectively. Increasing active alkali and sulfidity loading has significantly increased lignin removal caused by disruption of the cell wall structure for releasing lignin into black liquor in the cellulose extraction. The enzymatic hydrolysis of pulp was carried out with cellulase loading of 40 FPU per g substrate in the shaking incubator at 50°C and 150 rpm for 78 h. For each 24 h, the reducing sugar yield (DNS assay) has been observed. Even though the lignin and hemicellulose loss occurred along with higher active alkali loading, this condition tends to decrease its yield. The reducing sugar concentration varied between 7-8 g/L. Increasing active alkali and sulfidity was significantly decreased the reducing sugar per biomass. Pulp delignified by 17% active alkali and 20% sulfidity has demonstrated the maximum reducing sugar yield per biomass of 45.57% resulted after 72 h enzymatic hydrolysis. These results indicated that kraft pulping was success to degrade more lignin and hemicellulose content to facilitate the enzyme for breaking down the cellulose into its sugar monomer. A high loss of lignin and hemicellulose are not single factor to improve digestibility of SSB. This sugar has potential for yeast fermented into bioethanol.

  11. A modified efficient method for dental pulp stem cell isolation

    PubMed Central

    Raoof, Maryam; Yaghoobi, Mohammad Mehdi; Derakhshani, Ali; Kamal-abadi, Ali Mohammadi; Ebrahimi, Behnam; Abbasnejad, Mehdi; Shokouhinejad, Noushin

    2014-01-01

    Background: Dental pulp stem cells can be used in regenerative endodontic therapy. The aim of this study was to introduce an efficient method for dental pulp stem cells isolation. Materials and Methods: In this in-vitro study, 60 extracted human third molars were split and pulp tissue was extracted. Dental pulp stem cells were isolated by the following three different methods: (1) digestion of pulp by collagenase/dispase enzyme and culture of the released cells; (2) outgrowth of the cells by culture of undigested pulp pieces; (3) digestion of pulp tissue pieces and fixing them. The cells were cultured in minimum essential medium alpha modification (αMEM) medium supplemented with 20% fetal bovine serum(FBS) in humid 37°C incubator with 5% CO 2. The markers of stem cells were studied by reverse transcriptase polymerase chain reaction (PCR). The student t-test was used for comparing the means of independent groups. P <0.05 was considered as significant. Results: The results indicated that by the first method a few cell colonies with homogenous morphology were detectable after 4 days, while in the outgrowth method more time was needed (10-12 days) to allow sufficient numbers of heterogeneous phenotype stem cells to migrate out of tissue. Interestingly, with the improved third method, we obtained stem cells successfully with about 60% efficiency after 2 days. The results of RT-PCR suggested the expression of Nanog, Oct-4, and Nucleostemin markers in the isolated cells from dental pulps. Conclusion: This study proposes a new method with high efficacy to obtain dental pulp stem cells in a short time. PMID:24932197

  12. Agricultural fibres for pulp and paper manufacture in developed countries

    SciTech Connect

    Wong, A.

    1995-11-01

    Agricultural fibres are routinely used for the manufacture of paper products in developing countries. The agriculture (non-wood) pulp industry accounts more than 50% of the national pulp production in China and in India. In contrast, paper manufacturers of the developed countries have relied largely on wood pulp fibres since the 1950`s. During the past 3 decades, the global wood pulp production capacities has expanded substantially. There is a renewed interest to use agriculture-based fibres in place of wood, for the production of pulp and paper in developing countries. The alternative is driven, in part, by the growing shortage of commercial wood supply as caused by the over-cutting of the standing forest and the accelerated re-allocation of forest land for ecological and recreational uses. Although the shortage of wood supply can be alleviated partially by the adoption of higher-yield wood pulping technologies and by the increased use of waste paper. But ultimately, these remedial steps will be inadequate to meet the growing demand for paper products. There are several important factors which affect the use of agricultural fibres for pulp and paper manufacture in developed countries. For some on-purpose fibre crops, continued farm subsidy and repeal of certain sections of the Narcotics Act would be required. Agri-pulp production from agricultural cropping residues appears to be the most practical economic means to supplement the fibre needs of the paper industry. In the social context, agri-pulp implementation in North America would also provide lower taxes that would be accrued from the elimination of substantial annual subsidies to grain farmers from the government.

  13. Transplantation of dental pulp stem cells and platelet-rich plasma for pulp regeneration.

    PubMed

    Zhu, Xiaofei; Zhang, Chengfei; Huang, George T-J; Cheung, Gary S P; Dissanayaka, Waruna Lakmal; Zhu, Wenhao

    2012-12-01

    The loss of dental pulp may weaken teeth, rendering them susceptible to reinfection, fracture, and subsequent tooth loss. Therefore, regeneration of pulp is considered an ideal treatment to preserve teeth. The aim of this study was to explore the capacity of dental pulp stem cells (DPSCs) and platelet-rich plasma (PRP) to regenerate dental pulp in canine mature permanent teeth. Pulpectomy with apical foramen enlarged to a #80 file was performed in 16 upper premolars of 4 beagle dogs. Four experimental groups were randomly established: (1) the blood clot group, (2) the autologous DPSCs group, (3) the PRP group, and (4) the DP + PRP group (a mixture of DPSCs and PRP). Four lower premolars without any further treatment after pulpectomy were used as the control group. All teeth were sealed with mineral trioxide aggregate and composite. Twelve weeks after transplantation, the teeth were subjected to radiographic and histologic examination. Twenty-four of 32 experimental root canals gained newly formed tissues. All canals with an introduction of a blood clot showed histologic evidence of vital tissue formation. Cementum-like and periodontal ligament-like tissues along the internal root canal walls were typical structures in most cases. There is no significant difference between groups with or without autologous DPSC transplantation (exact chi-square test, P < .05). New vital tissues can be regenerated in permanent canine teeth after pulpectomy and enlargement of the apical foramen. Histologically, transplantation of DPSCs and/or PRP into root canals showed no enhancement in new tissue formation compared with inducement of a blood clot into the root canals alone. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Organosolv pulping: a versatile approach to wood refining

    SciTech Connect

    Lora, J.H.; Aziz, S.

    1985-08-01

    The fractionation of hardwoods into pulp, lignin, and hemicellulose has been studied in a multi-stage alcohol extraction pilot plant. By adjusting processing conditions, pulps of different properties were obtained. They have been found to be suitable to furnish components for writing, printing, and high-absorbency papers and as dissolving grades. By-product lignin and hemicelluloses are recovered in separate, high-yield fractions for which several potential commercial applications have been identified. The process is a low-capital-cost, low-environmental-impact alternative to kraft and sulfite pulping.

  15. Enzymatic treatment of mechanical pulp fibers for improving papermaking properties.

    PubMed

    Wong, K K; Richardson, J D; Mansfield, S D

    2000-01-01

    Three enzyme preparations (crude cellulase, laccase, and proteinase) were evaluated for their potential to improve the papermaking properties of mechanical pulp. After treating a long fibre-rich fraction of the pulp with enzyme, the fibres were recombined with untreated fines for handsheet making and testing. None of the enzymes altered the retention of fines or the consolidation of the furnish mix during handsheet formation. All three enzymes increased tensile stiffness index, which is a measure of the initial resistance of the handsheets to strain. Only the laccase preparation, an enzyme that modifies pulp lignin, consistently increased fibre bonding to enhance other strength properties of the handsheets.

  16. Harnessing the natural regenerative potential of the dental pulp.

    PubMed

    Smith, Anthony J; Smith, James G; Shelton, Richard M; Cooper, Paul R

    2012-07-01

    Biological solutions for the repair and regeneration of the dental tissues offer significant potential for improved clinical treatment outcomes. Translation of dental tissue-engineering approaches to the clinic will make considerable contributions to these outcomes in the future, but exploiting the natural regenerative potential of dentin-pulp to enhance wound-healing responses offers solutions for maintaining pulp vitality now. Strategies to harness the natural regenerative potential of the pulp must be based on a sound biological understanding of the cellular and molecular events taking place, and require careful consideration of the interplay of infection, inflammation, and regeneration. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Pulp biology: progress during the past 25 years.

    PubMed

    Trowbridge, Henry O

    2003-04-01

    During the past 25 years there has been a rapid expansion in our knowledge of the dentine and pulp complex. This paper provides representative examples of important advances that researchers have made in this field. Topics to be considered include: differentiation of odontoblasts, dentine matrix proteins, extent of odontoblast processes, pulpal stem cells, apoptosis, interstitial fluid pressure in normal and inflamed pulps, class II antigen-presenting cells of the pulp, cytokines, antibodies, pulpal calcifications, tertiary dentine and pulpal inflammation associated with bacterial contamination of exposed dentine beneath restorations.

  18. Method and apparatus for assaying wood pulp fibers

    SciTech Connect

    Gustafson, Richard; Callis, James B; Mathews, Jeffrey D; Robinson, John; Bruckner, Carsten A; Suvamakich, Kuntinee

    2009-05-26

    Paper pulp is added to a stain solution. The stain solution and pulp fibers are mixed to form a slurry. Samples are removed from the slurry and are admixed with dilution water and a bleach. Then, the fibers are moved into a flow cell where they are subjected to a light source adapted to stimulate fluorescence from the stained pulp fiber. Before the fiber slurry enters the flow cell it is mixed with a dilution water of bleach to reduce background fluorescence. The fluorescent light is collimated and directed through a dichroic filter onto a fluorescence splitting dichroic filter.

  19. Effects of pulp consistency and mixing intensity on ozone bleaching

    SciTech Connect

    Hurst, M.M. )

    1993-04-01

    Conventional wisdom holds that ozone bleaching is feasible only at low or high pulp consistencies. However, recent research suggests that ozone bleaching at medium consistency is possible under conditions of high-intensity mixing. This article presents experimental results for softwood and hardwood pulps that were ozone-bleached over a range of consistencies (3-40%) and mixing conditions. Ozone was pressurized and delivered by a proprietary automated system. Results indicate that ozone bleaching at medium consistency can be as effective as bleaching at high consistency. Medium-consistency bleaching has the advantage of greater selectivity, resulting in higher pulp viscosity.

  20. Acid hydrolysis of cellulosic fibres: Comparison of bleached kraft pulp, dissolving pulps and cotton textile cellulose.

    PubMed

    Palme, Anna; Theliander, Hans; Brelid, Harald

    2016-01-20

    The behaviour of different cellulosic fibres during acid hydrolysis has been investigated and the levelling-off degree of polymerisation (LODP) has been determined. The study included a bleached kraft pulp (both never-dried and once-dried) and two dissolving pulps (once-dried). Additionally, cotton cellulose from new cotton sheets and sheets discarded after long-time use was studied. Experimental results from the investigation, together with results found in literature, imply that ultrastructural differences between different fibres affect their susceptibility towards acid hydrolysis. Drying of a bleached kraft pulp was found to enhance the rate of acid hydrolysis and also result in a decrease in LODP. This implies that the susceptibility of cellulosic fibres towards acid hydrolysis is affected by drying-induced stresses in the cellulose chains. In cotton cellulose, it was found that use and laundering gave a substantial loss in the degree of polymerisation (DP), but that the LODP was only marginally affected. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Formation of carbonyl groups on cellulose during ozone treatment of pulp: consequences for pulp bleaching.

    PubMed

    Pouyet, Frédéric; Chirat, Christine; Potthast, Antje; Lachenal, Dominique

    2014-08-30

    The formation of carbonyl groups during the ozone treatment (Z) of eucalyptus (Eucalyptus grandis and Eucalyptus urophylla hybrid) kraft pulps and their behaviors during subsequent alkaline stages were investigated by the CCOA method with carbazole-9-carboxylic acid [2-(2-aminooxethoxy)-ethoxy] amide (CCOA) as the carbonyl-selective fluorescence label. Several pulp samples with or without lignin and hexenuronic acids (hexA) were used to elucidate the effects of these components when present in unbleached kraft pulp. Both hexA and lignin increased the formation of carbonyl groups on cellulose and hemicellulose during ozonation. It was concluded that radicals are likely formed when ozone reacts with either lignin or hexA. These carbonyl groups were involved in cellulose depolymerization during subsequent alkaline extraction stages with sodium hydroxide (E) and alkaline hydrogen peroxide (P, in ZEP or ZP). Their numbers decreased after E but increased during P when H2O2 was not stabilized enough. Several ways to minimize the occurrence of carbonyl group formation are suggested. Copyright © 2014. Published by Elsevier Ltd.

  2. Pulp response to dentine adhesives: A study on mature human pulps

    PubMed Central

    Kouros, Pantelis; Koliniotou-Koumpia, Eugenia; Koulaouzidou, Elisabeth; Helvatjoglu-Antoniades, Maria; Tziafas, Dimitrios

    2013-01-01

    Objective: To clinically investigate the antibacterial effects of a commercially available self-etch 12-methacryloyloxy- dodecylpyridinium bromide (MDPB)-containing adhesive system in comparison with its respective non-MDPB-containing adhesive and to evaluate the pulp responses when in use on human teeth. Materials and Methods: Sixty-two viable human teeth scheduled for extraction were used. Class V cavities were prepared on the buccal surfaces of the teeth and filled with the tested materials (Protect Bond/Clearfil AP-X, SE Bond/Clearfil AP-X and Dycal/Ketac Fill Plus) as a control group, according to manufacturer's recommendations. Randomly divided to two groups teeth remained intra-orally for 4 and 8 weeks. After extraction, teeth were decalcified, sectioned and stained using the Mayer's hematoxylin and eosin, and modified Brown-Brenn's technique. Pulp responses were evaluated microscopically under a microscope and remaining dentine thickness measured under a stereomicroscope. Results: No statistically significant differences regarding pulp inflammation or bacterial infiltration were found either for the materials tested or for periods of post-operative evaluation. Conclusions: The results suggested that for a short period of evaluation there are no quantitative differences, regardless to restoring material used. PMID:24966725

  3. Nestin expressions of exposed pulp after direct pulp capping by calcium hydroxide and platelet rich plasma

    PubMed Central

    Puspita, Sartika; Utoro, Totok; Haniastuti, Tetiana

    2016-01-01

    Objective: The aim of this study was to evaluate nestin expression of pulp tissue following direct pulp capping with platelet-rich plasma (PRP). Materials and Methods: The thirty sound teeth from Sprague-Dawley rats were used and divided into two groups: Groups 1, teeth were capped with calcium hydroxide/Ca(OH)2 (n = 15) and Group 2 with PRP (n = 15). After 1st, 7th, and 21st days, respectively, 5 teeth each group (American Dental Association 41) were processed for light microscopic examination. Expressions of nestin were assessed by immunohistochemical techniques. Results: Nestin expression of Ca(OH)2 on the distance place of exposure at 1st and 7th days were 80% and at 21st day were 60%. Nestin expression of PRP on the distance place at 1st day was 80%, 7th 100%, and 21st day was 80%. At day 21 observation, Kruskal–Wallis test shows nestin expression was increased significantly in PRP groups (P < 0.05), but it was not increase significantly compare with Ca(OH)2. Conclusion: PRP had ability as a direct pulp capping material to induce nestin expression. PMID:27403050

  4. A comparison of human dental pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents.

    PubMed

    Jalan, Anushka Lalit; Warhadpande, Manjusha M; Dakshindas, Darshan M

    2017-01-01

    Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. The histological data were subjected to Wilcoxon rank-sum test. The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P < 0.0001) and more continuous (P = 0.0001) with less pulpal inflammation (P = 0.0044) in comparison to Dycal. Based on the result of this study, Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion.

  5. A comparison of human dental pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents

    PubMed Central

    Jalan, Anushka Lalit; Warhadpande, Manjusha M.; Dakshindas, Darshan M.

    2017-01-01

    Context: Direct pulp capping involves the placement of a biocompatible agent on pulp tissue that has been inadvertently exposed from traumatic injury or by iatrogenic means. Aim: To compare the human pulp response to calcium hydroxide and Biodentine as direct pulp-capping agents. Materials and Methods: Pulp exposures were performed on the pulpal floor of forty human permanent premolars. The exposure sites were dressed with either Dycal or Biodentine as pulp-capping materials. After 45 days, teeth were extracted and processed for histological examination. Statistical Analysis: The histological data were subjected to Wilcoxon rank-sum test. Results: The dentinal bridges in teeth that were capped with Biodentine were significantly thicker (P < 0.0001) and more continuous (P = 0.0001) with less pulpal inflammation (P = 0.0044) in comparison to Dycal. Conclusion: Based on the result of this study, Biodentine can be suggested as the material of choice for direct pulp capping procedure instead of Dycal. However, further long-term follow-up in vivo human studies using Biodentine on cariously exposed pulpal teeth are warranted to derive a definite conclusion. PMID:28855762

  6. Preparation and characterization of cellulose nanofibers from de-pectinated sugar beet pulp.

    PubMed

    Li, Meng; Wang, Li-jun; Li, Dong; Cheng, Yan-ling; Adhikari, Benu

    2014-02-15

    Cellulose nanofibers (diameter=10-70 nm) were produced using chemical treatments (alkali treatment and bleaching) and high pressure homogenization from de-pectinated sugar beet pulp (DSBP). Chemical analysis and Fourier transform infrared spectroscopy (FTIR) indicated that the chemical treatments greatly removed the hemicellulose and lignin from the DSBP and significantly increased the cellulose content. The crystallinity of the cellulose nanofibers increased from 35.67% to 69.62% after alkali treatment and bleaching. The thermal degradation temperature of DSBP cellulose nanofibers was 271.7 °C which was found to be 47.3 °C higher than that of the untreated DSBP. The DSBP cellulose nanofibers can be preferably used as reinforcement in the biocomposite material at high temperature.

  7. Experimental studies on waste paper pulp biodegradation.

    PubMed

    Sharma, R; Sharma, D; Rao, K S; Jain, R C

    2002-07-01

    In continuation of their studies on Biodegradation of cellulosic waste materials, the authors have presented their experimental data on biodegradation on waste paper pulp. Greater efficiency in the cow dung and M3 culture experimental setups have been pointed out and discussed. Necessity of detailed data evaluation of temperature, pH, dry weight, cellulose, protein, carbohydrate, Nitrate, Phosphate & Potassium levels is suggested. Derivation of %, absolute and increase/decrease % of BOO, COD and VS have been pointed out for the first time in solid waste Biodegradation. Further data evaluation and derivation of critical reaction rate kinetics have been recommended for further studies in solid waste-degradation to achieve quicker Bioconversion of cellulosic wastes into compost.

  8. Low Odor, High Yield Kraft Pulping

    SciTech Connect

    W.T. McKean

    2000-12-15

    In laboratory cooks pure oxygen was profiled into the circulation line of a batch digester during two periods of the cooking cycle: The first injection occurred during the heating steps for the purpose of in-situ generation of polysulfide. This chip treatment was studied to explore stabilization against alkaline induced carbohydrate peeling and to increase pulp yield. Under optimum conditions small amounts of polysulfide were produced with yield increase of about 0.5% These increases fell below earlier reports suggesting that unknown differences in liquor composition may influence the relative amounts of polysulfide and thiosulfate generated during the oxidation. Consequently, further studies are required to understand the factors that influence the ratios of those two sulfur species.

  9. Preventing Strength Loss of Unbleached Kraft Pulp

    SciTech Connect

    Martin Hubbe; Richard Venditti; John Heitmann

    2003-04-16

    Kraft pulp fibers lose inter-fiber bonding ability when they are dried during the manufacture of paper. Adverse environmental consequences of this loss include (a) limitations on the number of times that kraft fibers can be recycled, (b) reduced paper strength, sometimes making it necessary to use heavier paper or paperboard to meet product strength requirements, increasing the usage of raw materials, (c) decreased rates of paper production in cases where the fiber furnish has been over-refined in an attempt to regain inter-fiber bonding ability. The present study is the first of its type to focus on unbleached kraft fibers, which are a main ingredient of linerboard for corrugated containers. About 90 million tons of unbleached kraft fiber are used worldwide every year for this purpose.

  10. Characterization of a thermostable and alkaline xylanase from Bacillus sp. and its bleaching impact on wheat straw pulp.

    PubMed

    Saleem, Mahjabeen; Aslam, Farheen; Akhtar, Muhammad Saleem; Tariq, Mohsin; Rajoka, Muhammad Ibrahim

    2012-02-01

    Delignification efficacy of xylanases to facilitate the consequent chemical bleaching of Kraft pulps has been studied widely. In this work, an alkaline and thermally stable cellulase-less xylanase, derived from a xylanolytic Bacillus subtilis, has been purified by a combination of gel filtration and Q-Sepharose chromatography to its homogeneity. Molecular weight of the purified xylanase was 61 kDa by SDS-PAGE. The purified enzyme revealed an optimum assay temperature and pH of 60°C and 8.0, respectively. Xylanase was active in the pH range of 6.0-9.0 and stable up to 70°C. Divalent ions like Ca(2+), Mg(2+) and Zn(2+) enhanced xylanase activity, whereas Hg(2+), Fe(2+), and Cu(2+) were inhibitory to xylanase at 2 mM concentration. It showed K ( m ) and V ( max ) values of 9.5 mg/ml and 53.6 μmol/ml/min, respectively, using birchwood xylan as a substrate. Xylanase exhibited higher values of turn over number (K (cat)) and catalytic efficiency (K (cat)/K (m)) with birchwood xylan than oat spelt xylan. Bleach-boosting enzyme activity at 30 U/g dry pulp displayed the optimum bio-delignification of Kraft pulp resulting in 26.5% reduction in kappa number and 18.5% ISO induction in brightness at 55°C after 3 h treatment. The same treatment improved the pulp properties including tensile strength and burst index, demonstrating its potential application in pre-bleaching of Kraft pulp.

  11. Antifungal activity of fruit pulp extract from Bromelia pinguin.

    PubMed

    Camacho-Hernández, I L; Chávez-Velázquez, J A; Uribe-Beltrán, M J; Ríos-Morgan, A; Delgado-Vargas, F

    2002-08-01

    The methanol extract of the fruit pulp of Bromelia pinguin was evaluated for its antifungal activity. The extract showed a significant activity against some Trichophyton strains, although Candida strains were generally insensitive.

  12. Effect of ripe fruit pulp on the sensory and nutritive quality of ready-to-eat breakfast cereal produced from maize and soybean flours and cassava starch blends.

    PubMed

    Enwere, N J; Ntuen, I G

    2005-02-01

    The effects of various concentrations of different ripe fruit pulps on the sensory and nutritive quality of breakfast cereal were studied. The breakfast cereal was formulated using 1 kg composite flour (composed of 600 g maize flour and 400 g soy flour) in addition to 100 g cassava starch, 225 g sugar and 12 g salt. Pineapple, pawpaw and banana ripe fruit pulps were added separately to the breakfast formulation at concentrations of 0, 100, 200, 300 and 400 g/kg composite flour. Using sensory evaluation, the data obtained showed that samples containing 100 g pineapple, 100 g banana pulp and 100 g pawpaw fruit pulp per kilogram of composite flour (equivalent to 7% of the total weight of the breakfast cereal formulation) were the most acceptable of all concentrations. These samples were comparable in sensory evaluation scores with the commercial breakfast cereal sample Golden morn. Chemical analysis also showed that there was increase in ss-carotene (vitamin A precursor) and vitamin C and a slight increase in the mineral content of the breakfast cereal as a result of the addition of fruit pulp.

  13. 40 CFR 430.60 - Applicability; description of the semi-chemical subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-chemical subcategory. 430.60 Section 430.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORY Semi-Chemical Subcategory § 430.60 Applicability; description of the semi-chemical subcategory... of pulp and paper at semi-chemical mills....

  14. Pulp-dentin Regeneration: Current State and Future Prospects.

    PubMed

    Cao, Y; Song, M; Kim, E; Shon, W; Chugal, N; Bogen, G; Lin, L; Kim, R H; Park, N-H; Kang, M K

    2015-11-01

    The goal of regenerative endodontics is to reinstate normal pulp function in necrotic and infected teeth that would result in reestablishment of protective functions, including innate pulp immunity, pulp repair through mineralization, and pulp sensibility. In the unique microenvironment of the dental pulp, the triad of tissue engineering would require infection control, biomaterials, and stem cells. Although revascularization is successful in resolving apical periodontitis, multiple studies suggest that it alone does not support pulp-dentin regeneration. More recently, cell-based approaches in endodontic regeneration based on pulpal mesenchymal stem cells (MSCs) have demonstrated promising results in terms of pulp-dentin regeneration in vivo through autologous transplantation. Although pulpal regeneration requires the cell-based approach, several challenges in clinical translation must be overcome-including aging-associated phenotypic changes in pulpal MSCs, availability of tissue sources, and safety and regulation involved with expansion of MSCs in laboratories. Allotransplantation of MSCs may alleviate some of these obstacles, although the long-term stability of MSCs and efficacy in pulp-dentin regeneration demand further investigation. For an alternative source of MSCs, our laboratory developed induced MSCs (iMSCs) from primary human keratinocytes through epithelial-mesenchymal transition by modulating the epithelial plasticity genes. Initially, we showed that overexpression of ΔNp63α, a major isoform of the p63 gene, led to epithelial-mesenchymal transition and acquisition of stem characteristics. More recently, iMSCs were generated by transient knockdown of all p63 isoforms through siRNA, further simplifying the protocol and resolving the potential safety issues of viral vectors. These cells may be useful for patients who lack tissue sources for endogenous MSCs. Further research will elucidate the level of potency of these iMSCs and assess their

  15. Stem cells in dental practice: perspectives in conservative pulp therapies.

    PubMed

    Casagrande, Luciano; Mattuella, Letícia Grando; de Araujo, Fernando Borba; Eduardo, Jacques

    2006-01-01

    Stem cells are undifferentiated cells that have the capacity to self-renew. They have been discovered in many adult tissues, including teeth. The Dental Pulp Stem Cells are involved in dentinal repair by activation of growth factors, released after caries process and have the ability to regenerate the dentin-pulp-like complex. The molecular/cellular research raises the possibilities to grow new tissues and biological structures for clinical application, providing cells for therapies including cell transplantation and tissue engineering.

  16. Neuropeptide K-like immunoreactivity in human dental pulp.

    PubMed

    Casasco, A; Calligaro, A; Springall, D R; Casasco, M; Poggi, P; Valentino, K L; Polak, J M

    1990-01-01

    Nerve fibres displaying such immunoreactivity were revealed by indirect immunofluorescence. Neuropeptide K-like immunoreactive fibres, entering the pulp within large nerve trunks, were distributed around blood vessels as well as in the stroma. Some immunoreactive fibres were also observed in the para-odontoblastic region. In view of the biological activity of neuropeptide K, it is tentatively proposed that it may act in the dental pulp as a regulatory peptide involved in neurogenic inflammation, blood flow regulation and sensory transmission.

  17. Considerations on the ultrastructural particularities of the dental pulp cells.

    PubMed

    Manolea, H; Deva, V; Bogdan, Fl; Moraru, Iren; Pancă, Oana-Adina; Caraivan, O

    2008-01-01

    We realized an ultrastructural study of the cells of the dental pulp, having in view their particularities relative to other types of conjunctive tissue. For this purpose, we selected five cases represented by teeth without subjective or objective symptomatology. Within the paper there are exposed the morphological aspects observed by means of electron microscopy. The results are then discussed in relation with a series of observations made by other researchers regarding the particularities of the pulp cells structures.

  18. Physico-chemical evaluation of Dovyalis spp

    USDA-ARS?s Scientific Manuscript database

    The purpose of this research was to establish physico-chemical characterization of dovyalis hybrid fruits (MIA 25359). Samples of 30 fruits were characterized by evaluation of fruit and seed weight, length and width, percentage and number of seeds per fruit, peel and pulp percentage, total soluble s...

  19. Active Nanomaterials to Meet the Challenge of Dental Pulp Regeneration

    PubMed Central

    Keller, Laetitia; Offner, Damien; Schwinté, Pascale; Morand, David; Wagner, Quentin; Gros, Catherine; Bornert, Fabien; Bahi, Sophie; Musset, Anne-Marie; Benkirane-Jessel, Nadia; Fioretti, Florence

    2015-01-01

    The vitality of the pulp is fundamental to the functional life of the tooth. For this aim, active and living biomaterials are required to avoid the current drastic treatment, which is the removal of all the cellular and molecular content regardless of its regenerative potential. The regeneration of the pulp tissue is the dream of many generations of dental surgeons and will revolutionize clinical practices. Recently, the potential of the regenerative medicine field suggests that it would be possible to achieve such complex regeneration. Indeed, three crucial steps are needed: the control of infection and inflammation and the regeneration of lost pulp tissues. For regenerative medicine, in particular for dental pulp regeneration, the use of nano-structured biomaterials becomes decisive. Nano-designed materials allow the concentration of many different functions in a small volume, the increase in the quality of targeting, as well as the control of cost and delivery of active molecules. Nanomaterials based on extracellular mimetic nanostructure and functionalized with multi-active therapeutics appear essential to reverse infection and inflammation and concomitantly to orchestrate pulp cell colonization and differentiation. This novel generation of nanomaterials seems very promising to meet the challenge of the complex dental pulp regeneration. PMID:28793649

  20. Biotechnological potential of coffee pulp and coffee husk for bioprocesses.

    PubMed

    Pandey; Soccol; Nigam; Brand; Mohan; Roussos

    2000-10-01

    Advances in industrial biotechnology offer potential opportunities for economic utilization of agro-industrial residues such as coffee pulp and coffee husk. Coffee pulp or husk is a fibrous mucilagenous material (sub-product) obtained during the processing of coffee cherries by wet or dry process, respectively. Coffee pulp/husk contains some amount of caffeine and tannins, which makes it toxic in nature, resulting the disposal problem. However, it is rich in organic nature, which makes it an ideal substrate for microbial processes for the production of value-added products. Several solutions and alternative uses of the coffee pulp and husk have been attempted. These include as fertilizers, livestock feed, compost, etc. However, these applications utilize only a fraction of available quantity and are not technically very efficient. Attempts have been made to detoxify it for improved application as feed, and to produce several products such as enzymes, organic acids, flavour and aroma compounds, and mushrooms, etc. from coffee pulp/husk. Solid state fermentation has been mostly employed for bioconversion processes. Factorial design experiments offer useful information for the process optimization. This paper reviews the developments on processes and products developed for the value-addition of coffee pulp/husk through the biotechnological means.