scholarly journals Development of a Technique for Removal of Hexenuronic Acid in ECF-Bleached Pulp Using UV Irradiation

2012 ◽  
Vol 66 (3) ◽  
pp. 287-292
Author(s):  
Shiho Tsuji (Katsukawa) ◽  
Shoichi Miyawaki ◽  
Tomoaki Koyanagi
Keyword(s):  
Uv Irradiation ◽  
Bleached Pulp ◽  
Hexenuronic Acid

scholarly journals Impact on the Filtrate from Bleached Pulp Treated with Peroxymonosulfuric Acid for Effective Removal of Hexenuronic Acid

2011 ◽  
Vol 65 (10) ◽  
pp. 1071-1075 ◽  
Author(s):  
Eiko Kuwabara ◽  
Tetsuo Koshitsuka ◽  
Mikio Kajiyama ◽  
Hiroshi Ohi
Keyword(s):  
Bleached Pulp ◽  
Effective Removal ◽  
Hexenuronic Acid

Does the kappa number method accurately reflect lignin content in nonwood pulps?

TAPPI Journal ◽  
2018 ◽  
Vol 17 (11) ◽  
pp. 611-617
Author(s):  
Sabrina Burkhardt
Keyword(s):  
Lignin Content ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Original Data ◽  
Kappa Number ◽  
Klason Lignin ◽  
Organic Functional Groups ◽  
Pulp Properties ◽  
Wood Pulps ◽  
Hexenuronic Acid

The traditional kappa number method was developed in 1960 as a way to more quickly determine the level of lignin remaining in a completed or in-progress pulp. A significantly faster approach than the Klason lignin procedure, the kappa number method is based on the reaction of a strong oxidizing agent (KMnO4) with lignin and small amounts of other organic functional groups present in the pulp, such as hexenuronic acid. While the usefulness of the kappa number for providing information about bleaching requirements and pulp properties has arguably transformed the pulp and paper industry, it has been mostly developed for kraft, sulfite, and soda wood pulps. Nonwood species have a different chemical makeup than hardwood or softwood sources. These chemical differ-ences can influence kappa and Klason measurements on the pulp and lead to wide ranges of error. Both original data from Sustainable Fiber Technologies’ sulfur and chlorine-free pulping process and kappa and Klason data from various nonwood pulp literature sources will be presented to challenge the assumption that the kappa number accurately represents lignin content in nonwood pulps.

Wavelength-specific Activation of MAP Kinase Family Proteins by Monochromatic UV Irradiation¶

2001 ◽  
Vol 73 (2) ◽  
pp. 147 ◽  
Author(s):  
Yukihito Kabuyama ◽  
Miwako K. Homma ◽  
Masayuki Sekimata ◽  
Yoshimi Homma
Keyword(s):  
Map Kinase ◽  
Uv Irradiation ◽  
Kinase Family

The Study of Photoreversibility, Photopolimerization and Photocleavage Properties of Polyurethane Coumarin by Means of Electronic Spectrometry and AFM Methods

2017 ◽  
Vol 68 (7) ◽  
pp. 1632-1635
Author(s):  
Silviu Gurlui ◽  
Emil Buruiana ◽  
Ioan Gabriel Sandu ◽  
Mitachi Strat
Keyword(s):  
Uv Irradiation ◽  
Room Temperature ◽  
Dimethyl Formamide ◽  
Photon Excitation ◽  
Photochemical Properties ◽  
Film State

The spectroscopic and photochemical properties of polyurethane coumarin (PUC) in dimethyl sulf-oxide (DMSO), thetra hydro furan (THF), dimethyl formamide (DMF) and film state were investigated at room temperature under one photon excitation. The results show that under irradiation of l ] 310 nm photodimerization process are increased and under UV irradiation with l[ 260 nm, photocleavage of polymer have been evidenced, too.

The Influence of Some Factors on Spirolactone Stability in Solution

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Daniela Lucia Muntean ◽  
Silvia Imre ◽  
Cosmina Voda
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Uv Irradiation ◽  
High Performance ◽  
Degradation Products ◽  
Simultaneous Action ◽  
Ethanolic Solution ◽  
Degradation Processes ◽  
Stable Solutions ◽  
Preformulation Study

The influence of some factors on spironolactone stability in solution was studied, by applying high-performance liquid chromatography, as a part of a pharmaceutical preformulation study in order to obtain a spironolactone solution for alopecia treatment. Solutions of 1 mg/ml spironolactone in aqueous ethanolic solution 1 : 1 and in 20 mM cyclodextrines solutions (b-, hydroxi-b- and methyl-b-cyclodextrine) was used, maintained at 8 and 22 �C, protected from light and after UV irradiation at 254 nm. The main degradation products were 7a-thiospirolactone and canrenone. The most stable solutions were the alcoholic ones and with methyl-beta-cyclodextrine, but the simultaneous action of temperature and UV irradiation allowed degradation processes after one hour of exposure, more aggressive in the presence of methyl-beta-cyclodextrine. In conclusion, for alopecia treatment with spironolactone a 1 mg/mL ethanolic solution could be used and it is recommendable the protection of treated zone.

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