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Waste pulps as biosorbents for metal recoveryAl-Haj Ali, Ahmad M. January 1984 (has links)
No description available.
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Selected current managerial problems of the pulp and paper industryAntoniello, Victor Mathew January 1965 (has links)
Thesis (M.B.A.)--Boston University. Note: missing page 90. / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2999-01-01
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Fate and effects of pulp mill effluent solids in the soil environmentFraser, Donald Scott. January 2007 (has links)
Thesis (Ph.D. Earth and Ocean Sciences)--University of Waikato, 2007. / Title from PDF cover (viewed February 26, 2008) Includes bibliographical references (p. 148-164)
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The determination of pulp vitality by the use of thermal and electric stimuli thesis submitted in partial fulfillment ... oral diagnosis ... /Reynolds, Richard L., January 1965 (has links)
Thesis (M.S.)--University of Michigan, 1965.
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A biochemical study of human tooth pulp response to cariesLe Bell, Yrsa. January 1980 (has links)
Thesis (doctoral)--University of Turku, 1980. / Includes 6 separately published papers in support of the thesis. "Also published in Proceedings of the Finnish Dental Society, vol. 76, suppl. 1." Includes bibliographical references.
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The determination of pulp vitality by the use of thermal and electric stimuli thesis submitted in partial fulfillment ... oral diagnosis ... /Reynolds, Richard L., January 1965 (has links)
Thesis (M.S.)--University of Michigan, 1965.
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A biochemical study of human tooth pulp response to cariesLe Bell, Yrsa. January 1980 (has links)
Thesis (doctoral)--University of Turku, 1980. / Includes 6 separately published papers in support of the thesis. "Also published in Proceedings of the Finnish Dental Society, vol. 76, suppl. 1." Includes bibliographies.
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Enzymatic pitch control in the kraft pulping and bleaching of Eucalyptus spp.Scheepers, Gerhardus C. (Gerhardus Coenraad) 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The extractive materials in wood often cause pitch problems in pulp mills. During pulping and
bleaching extractives are released from the wood and pulp and later stick to ceramic and metal
parts, forming pitch deposits. Pitch deposits impair both product quality and production rates. It
decreases the efficiency of pulp washing, screening, centrifugal cleaning, and refining, and can
disrupt many paper machine operations. The deposits also break loose from equipment and
cause spots in the final product. There are a few triggering mechanisms that induce pitch
deposition. Hydrodynamic or mechanical shear can destabilise the colloidal pitch emulsion,
causing pitch to agglomerate and deposits to form. Similarly, sudden temperature drops and/or
pH shocks and/or the introduction of water hardness ions from fresh water inlets or showers can
also cause pitch deposits by destabilising the colloidal pitch emulsion. Inorganic salts, such as
calcium carbonate, can catalyse pitch deposition by acting as the building blocks for the sticky
pitch. Calcium ions in the white water can react with fatty acids, forming insoluble, sticky
calcium soaps. Triglycerides have also been shown to be a major contributor to pitch deposition
in kraft pulping and bleaching mills. It forms a sticky deposit to which less sticky particles
attach.
To attain an improved understanding of pitch problems associated with the kraft pulping and
bleaching of Eucalyptus spp., various analyses were done on wood- and pulp extractives and
pitch from a South African kraft pulp mill. High molecular weight compounds (involatile)
constituted a large portion of the extracts and pitch. Approximately 40% of volatile Eucalyptus
grandis extract was f3-sitosterol, with fatty acids (22.8%) and triglycerides (15.5%) also making
a substantial contribution. Fatty acid amides were a prominent fraction of pulp extracts from the
latter stages of bleaching. The amides constituted 38.3% and triglycerides 10.1% to total volatile
pitch deposits.
Lipases hydrolyse triglycerides and could therefore help to reduce pitch problems. Consequently
381 filamentous fungi isolated from indigenous and commercial forests in South Africa were
screened for lipase activity on tributyrin and Tween 80. Eight strains were selected and the
tributyrin and Tween 80 assays were repeated by monitoring lipase activity over a seven-day period. The selected strains were also assayed for their activity toward p-nitrophenyl palmitate.
Ophiostoma piliferum Cartapip 58™ and Phanerochaete chrysosporium BKM-F-1767, two
strains known for respectively their biodepitching and biopulping ability, were' used as controls.
A few of the strains compared well and even outperformed the control strains, indicating their
potential for use in pitch control.
The effect of pretreatment with the eight selected fungal strains on E. grandis wood- and pulp
extractives was determined. Cartapip 58™ and P. chrysosporium BKM-F-1767 were used as
control strains. Several of the strains compared well to the control strains in their ability to
reduce the triglyceride content of wood extract. The South African isolate, white-rot fungus
Phanerochaete psuedomagnoliae nom. prov., reduced triglyceride content significantly.
Consequently it can act as an agent for both biopulping and biodepitching. The treated wood
samples had a lower triglyceride content than the sterile controls. Consequently more
triglycerides would be released into process waters by the sterile controls than the treated
samples. The effect of commerciallipases on deposited brown stock pulp extract was also
evaluated. The lipases did not reduce the triglyceride content of the deposited extract. The
addition of lipases in pulping and bleaching processes would therefore not affect already
deposited pitch. / AFRIKAANSE OPSOMMING: Die ekstrakstowwe van hout veroorsaak dikwels 'n neerslag tydens verpulping. Gedurende
verpulping en bleiking kom ekstrakstowwe van die hout enpulp vry en kleef aan keramiek- en
metaalonderdele. Gevolglik benadeel dié neerslag produkkwaliteit en produksietempo. Dit
verlaag die effektiwiteit van pulpwas, sifting, sentrifugale skoonmaakprosesse en suiwering, en
kan die werkverrigting van papiermasjiene ontwrig. Die neerslag kan ook later los breek en
kolletjies op die finale produk veroorsaak. Verskeie meganismes kan die neerslag veroorsaak.
Hidrodinamiese of meganiese wrywing kan die kolloïdale ekstrakstofemulsie destabiliseer en
sodoende die ekstrakstof laat konglomereer en neerslaan. Op soortgelyke wyse veroorsaak
skielike temperatuurverlaging en/of pH-skokke en/of die toevoeging van ione in varswater om
waterhardheid te beheer ook die neerslag deur die kolloïdale ekstrakstofemulsie te destabiliseer.
Anorganiese sout soos kalsiumkarbonaat kan neerslagvorming kataliseer omdat dit optree as
bousteen vir die klewerige, sementagtige ekstrakstowwe. Kalsiumione in die proseswater kan
ook reageer met vetsure om onoplosbare, klewerige kalsiumsepe te vorm. Dit is bewys dat
trigliseriede een van die hoofoorsake is in die vorming van die neerslag tydens kraft verpulpingen
bleikingprosesse.
Om die neerslagreaksie wat met die kraft verpulping en bleiking van Eucalyptus spp. geassosieer
word, beter te verstaan, is verskeie analises op hout- en pulpekstrakte asook die neerslag van 'n
Suid-Afrikaanse kraft verpulpingsaanleg uitgevoer. Hoë molekulêre massa (nie-vlugtige)
stowwe het 'n groot gedeelte van die ekstrakte en neerslag uitgemaak. Ongeveer 40% van die
vlugtige Eucalyptus grand is ekstrak bestaan uit ~-sitosterol met vet sure (22.8%) en trigliseriede
(15.5%) wat ook aansienlike bydraes lewer. Vetsuuramiede verteenwoordig 'n beduidende
komponent van pulpekstrak by die laaste stadiums van bleiking. Die amiede het 38.3% en
trigliseriede 10.1%tot die vlugtige fraksie van die neerslag bygedra.
Lipases hidroliseer trigliseriede en kan dus help om neerslagprobleme te voorkom. Gevolglik is
381 filamentagtige fungi geïsoleer uit inheemse en kommersiële woude van Suid-Afrika en hul
lipase-aktiwiteit op tributyrin en Tween 80 geëvalueer. Agt rasse is geselekteer en die tributyrin
en Tween 80 toetse is herhaal deur lipase-aktiwiteit oor 'n sewe-dag periode te monitor. Die
geselekteerde rasse is ook getoets vir lipase-aktiwiteit met p-nitrofenielpalmitaat. Ophiostoma piliferum Cartapip 58™ en Phanerochaete chrysosporium BKM-F-1767, twee rasse wat
daarvoor bekend staan vir onderskeidelik hul vermoë om houtekstrakstowwe te verminder en te
bioverpulp, is as kontroles gebruik. 'n Paar van die geselekteerde rasse het goed vergelyk en
selfs beter presteer as die kontrolerasse; 'n aanduiding van hul potensiaal om neerslagreaksies te
beheer.
Die effek van voorafbehandeling met die agt geselekteerde fungi rasse op E. grandis hout- en
pulpekstrak is vasgestel. Cartapip 58™ en P. chrysosporium BKM-F-1767 is gebruik as
kontrolerasse. Verskeie rasse het goed vergelyk met die kontrolerasse in hul vermoë om die
trigliseriedinhoud van die houtekstrak te verlaag. Die Suid-Afrikaanse isolaat,
witverrottingswam Phanerochaete pseudomagnoliae nom. prov., het ook die trigliseried inhoud
beduidend verminder. Gevolglik sou dit as 'n middel kon dien vir beide neerslagvoorkoming en
bioverpulping. Die trigliseriedinhoud van die behandelde monsters was laer as dié van steriele
kontroles. Gevolglik sal meer trigliseriede in proseswater vrygestel word deur die steriele
kontroles as die behandelde monsters. Die effek van kommersiële lipases op ongebleikte kraft
pulpekstrakneerslag is ook geëvalueer. Omdat lipases nie die trigliseriedinhoud van die neerslag
kon verlaag nie sal die gebruik van lipases dus nie die ekstrakstofneerslag in verpulpings- en
bleikingsprosesse beïnvloed nie.
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The pro-inflammatory and calcification effects of DMP-1 on pulp fibroblasts. Implications for the prevention of dental pulp calcifc metamorphosisAbd-Elmeguid, Ashraf A.E. Unknown Date
No description available.
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Mechanical Pulp Based Nano-ligno-cellulose : Production, Characterisation and their Effect on Paper PropertiesOsong, Sinke Henshaw January 2014 (has links)
Almost all research on biorefinery concepts are based on chemical pulping processes and ways of utilising lignin, hemicelluloses and extractives as well as a part of the remaining cellulose for production of nano materials in order to create more valuable products than today. Within the Forest as a Resource (FORE) research program at FSCN we are utilising the whole chain of unit processes from forestry to final products as paper and board, where the pulping process research focus on high yield process as TMP and CTMP. As these process solutions are preserving or only slightly changing the properties of the original wood polymers and extractives, the idea is to find high value adding products designed by nature. From an economic perspective, the production of nanocellulose from a chemical pulp is quite expensive as the pulp has to be either enzymatically (e.g. mono-component endoglucanase) pre-treated or chemically oxidised using the TEMPO (2,2,6,6 - tetramethyl-piperidine-1-oxil) - mediated oxidation method in order to make it possible to disrupt the fibres by means of homogenisation. In high yield pulping processes such as in TMP and CTMP, the idea with this study was to investigate the possibility to use fractions of low quality materials from fines fractions for the production of nano-ligno-cellulose (NLC). The integration of a NLC unit process in a high yield pulping production line has a potential to become a future way to improve the quality level of traditional products such as paper and board grades. The intention of this research work was that, by using this concept, a knowledge base can be created so that it becomes possible to develop a low-cost production method for its implementation. In order to study the potential of this concept, treatment of thermo-mechanical pulp (TMP) fines fractions were studied by means of homogenisation It seems possible to homogenise fine particles of thermo-mechanical pulp (1% w/v) to NLC. A correspond fines fraction from bleached kraft pulp (BKP) was tested as a reference at 0.5% w/v concentration. The objective presented in this work was to develop a methodology for producing mechanical pulp based NLC from fines fractions and to utilise this material as strength additives in paper and board grades. Laboratory sheets of CTMP and BKP, with addition of their respective NLC, were made in a Rapid Köthen sheet former. It was found that handsheets of pulp fibres blended with NLC improved the z-strength and other important mechanical properties for similar sheet densities. The characterisation of the particle size distribution of NLC is both important and challenging and the crill methodology developed at Innventia (former STFI) already during the 1980s was tested to see if it would be both fast and reliable enough. The crill measurement technique is based on the optical responses of a micro/nano particle suspension at two wavelengths of light; UV and IR. The crill value of TMP and CTMP based nano-ligno-cellulose were measured as a function of the homogenisation time. Results showed that the crill value of both TMP-NLC and CTMP-NLC correlated with the homogenisation time.
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