Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 158 for “"bleaching"”.
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Electrochemically mediated oxygen bleaching of pulp
… in a study of electrochemically mediated oxygen bleaching of unbleached Kraft softwood pulp. The atmospheric reactor was used to help elucidate the effects of reactants in electrochemically mediated oxygen bleaching. In addition, the electrochemical behaviour of the reactants, which was measured …
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Coral bleaching responses in Sodwana Bay, South Africa
This study assessed the bleaching response (BR) of coral colonies within the central reef complex in Sodwana Bay, South Africa. Bleach surveys were conducted at 16 sites on 8 reefs over the period of 2007 to 2013. A total of 12 858 coral colonies from 30 taxa were randomly sampled and colonies were …
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Production of bleaching powder by the fluidized powder technique.
Thesis: B.S., Massachusetts Institute of Technology, Department of Chemical Engineering, 1945
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Influence of a bleaching agent on stained direct composite resins
… staining without optimal results. Vital tooth bleaching has over 90% success rates in whitening discoloured teeth and this may be an alternative treatment modality for discoloured composite resins. Aim: The aim of this study was to determine whether tooth bleaching agents alter the colour of …
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Structural changes to Pinus radiata wood lignin during kraft pulping and bleaching
… assist the development of improved pulping and bleaching sequences. However, before this can be done, it is necessary to develop approaches to lignin isolation which provide more representative lignin samples without resorting to what are often very tedious extraction procedures. A key …
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Utilization of the vacuum form machine: Custom mouthguards versus esthetic bleaching trays
… recommended mouthguards, 60.2% recommended home bleaching trays, 37.6% provided patient information on mouthguards, 37.1% provided patient information on home bleaching trays, 16.5% inquired on patient questionnaires about mouthguard protection during contact sports,and 17.3% inquired on patient …
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HISTOLOGICAL RESPONSES OF THE SEA ANEMONE A. PALLIDA TO BLEACHING INDUCING STRESSES
… of symbiotic algae, a phenomenon known as coral bleaching, becomes indeed more and more frequent throughout the globe and already urged scientists to study its mechanisms for more than a decade. Their research highlighted the central role of reactive oxygen species in the collapse of symbiosis. …
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Microhardness and bleaching effectiveness on human tooth enamel after the application of nanohydroxyapatite
Various bleaching agents, including hydrogen peroxide and carbamide peroxide, have been used in vital and non-vital bleaching. Nanohydroxyapatite synthesised using green methods are reported to possess bleaching potential. Although studies have indicated a reduction in enamel microhardness …
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A study of physical factors which influence the efficiency of flour bleaching with nitrogen trichloride
Call number: LD2668 .T4 1949 D61
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A study of physical factors which influence the efficiency of flour bleaching with nitrogen trichloride
Call number: LD2668 .T4 1949 D61
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The in vitro effect of a tooth bleaching agent on coffee and wine stained teeth
… study is to assess the efficacy of a tooth bleaching agent by evaluating the degree of color change with the use of a spectrophotometer and not by the usual subjective, visual methods. Methodology: Twenty specimens of human teeth will be collected, polished and divided into two groups. A …
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The effect of two bleaching products on microhardness and surface texture of different dental aesthetic restorative materials
In this study, the effect of two different bleaching agents on the microhardness and the surface texture of six different aesthetic restorative materials were evaluated. <br>Four different composite resins (a hybrid, a flow, a micro-hybrid and a nano-hybrid), an ormocer, and a ceramic, were used …
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Expression of 3-hydroxy-3-methylglutaryl coenzyme a reductase in maize as influenced by light and bleaching herbicides
… conditions of strong light pretreatment with the bleaching herbicides clomazone, norflurazon, fluridone and acifluorfen stimulated by 4-to 7-fold the activity of HMGR extracted from 'Dekalb XL72AA' maize seedlings.
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A Chemical Comparison of Two Different Oxidizing Bleaches and the History of Early European Paper and Papermaking
Background: The bleaching of paper is an important and controversial treatment employed in the conservation of art. The use of a bleach may greatly enhance the quality of an image but at a cost of lost structural integrity. In order to fully consider the ramifications of bleaching a paper artifact, …
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On the physical refining of edible oils for obtaining high quality products
… refining of vegetable oils, emphasizing the bleaching step. As first step, a HPLC methodology for simultaneous quantification of carotenes and tocols was developed and validated, and lately, it was used by our research groups. Then, bleaching step of palm oil, nowadays the most consumed oil …
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State-of-the-art pollution control technology : global market pull or domestic regulatory push?
… replace heavily polluting chlorine bleaching with environmentally benign oxygen bleaching was used. Three hypotheses were proposed to explain this action: (i) oxygen bleaching was adopted because of the actual and anticipated domestic regulation of environmental residues and cultural …
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Irradiação da luz violeta associada ao peróxido de carbamida para clareamento dentário em consultório: uma revisão sistemática e meta-análise
… has been proposed to enhance the in-office bleaching effect of carbamide peroxide. However, a systematic review and meta-analysis are needed to summarize the evidence and guide clinical recommendations. The objective of this study was to evaluate, through a systematic review and …
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WET PROCESSING OF FIBRE BLENDS CONTAINING PRE HARVEST RETTED FLAX
… yarns. Appropriate, traditional scouring and bleaching processes were established for these blends. The finer, whiter fibres from the early-desiccated crop were found to respond better to the mild bleaching conditions required for the flax/wool blend. In some cases this also led to increased …
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