12 research outputs found
Behovsstyrd kommunikation. Ett förarbete för Pedagog Göteborg.
Syfte: Att skapa underlag för behovsstyrd kommunikation pÄ Pedagog Göteborg.
Teori: Teorin tar sin utgÄngspunkt i forskning kring organisationer och fokuserar dÀrefter pÄ en lÀrande organisation, lÀrande inom organisationen och specifikt lÀrande för pedagoger. Avsnittet avslutas med teori kring organisationskommunikation och content marketing.
Metod: Kvalitativa djupintervjuer med tio pedagoger med olika ansvarsomrÄden frÄn sex av Göteborgs stadsdelar samt utbildningsförvaltningen.
Resultat: Pedagog Göteborg har möjlighet att uppnÄ behovsstyrd kommunikation om redaktionen hÄller sig uppdaterad genom att ingÄ i olika nÀtverk samt fokusera pÄ att det Àr pedagogernas behov som ska styra. De har möjlighet att bemöta respondenternas behov nÀr det gÀller att skapa en digital mötesplats dÀr pedagoger inspirerar varandra, en evenemangskalender och behovet av att fÄ reda pÄ vad som hÀnder i form av lokala satsningar eller teman. Om Pedagog Göteborg bestÄr av en professionell redaktion sÄ kan de ocksÄ tillgodose behovet av kontrollerade inlÀgg som Àr kopplade till forskning. Av de behov som respondenterna har visat pÄ Àr tid för reflektion det enda behovet som Pedagog Göteborg inte har möjlighet att tillgodose pÄ egen hand. Ansvaret för att pedagogerna har tid och möjlighet till professionell utveckling och kollegialt lÀrande ligger pÄ de pedagogiska ledarna. Eftersom Göteborgs Stads utbildning arbetar mot att vara en lÀrande organisation sÄ uppstÄr det inte en krock mellan organisationens behov och pedagogernas behov. Genom att Pedagog Göteborg blir en sajt för alla pedagoger i Göteborgs stad kan man anvÀnda sajten som ett verktyg för att frÀmja kollegialt lÀrande och erfarenhetsutbyte som gynnar verksamhetens mÄl
13C assignments of the carbon atoms in the aromatic rings of lignin model compounds of the arylglycerol ÎČ-aryl ether type
Review: Light-Induced Yellowing Of Lignocellulosic Pulps - Mechanisms And Preventive Methods
This review will focus on recent progress regarding the mechanisms of light-induced discoloration of mechanical and chemimechanical pulps and on the proposed preventive treatments. It is evident that the mechanisms behind photoyellowing of lignin-rich pulps are complex and that several types of reaction pathways may coexist. Photoyellowing proceeds via one initial fast phase and a slower following phase. The fast phase has been ascribed to oxidation of free phenolic groups and/or hydroquinones and catechols to photoproducts of mainly quinonoid character. A multitude of reactions involving several lignin subunits are possible. Important intermediates are phenoxyl radicals, and to some extent ketyl radicals. The importance of the phenacyl aryl ether pathway might be more important than previously thought, even though the original content of such groups is low in lignin. Even though many preventive methods against photoyellowing have been suggested, no cost-efficient treatment is available to hinder photoreversion of lignin-containing paper permanently. Suggested methods for stabilization include chemical modification (etherification and esterification), coating the paper product, addition of radical scavengers, excited state quenchers, or ultraviolet absorbing compounds
Important Issues and Results from Knut Lundquist's Lignin Research at Chalmers
This is a manuscript originally written by Knut Lundquist and Jim Parkas in a more popular science spirit on topics in lignin chemistry where Knut and Chalmers has contributed and Knut's view on the bearing of this research on lignin chemistry. The manuscript was never published and was translated from Swedish by Ulla Westermark and Jim Parkas with a new title. The following topics are briefly addressed: stereochemistry and its implication on lignin structure and lignin biosynthesis, lignin-carbohydrate bonds, oxidative lignin degrading enzymes, reactions of beta-ethers at neutral and acidic conditions
Quantitative lignin analysis based on permanganate oxidation
Qualitative lignin analysis relies rather much on studies of lignin degradation products. As concerns precise quantification of ligninâs composition such studies in general have obvious limitations. Aromatic acids obtained on permanganate oxidation of pretreated lignins (cleavage of ethers and alkylation of phenolic groups) offer a possibility to estimate the amounts of differently substituted aromatic units in lignins. An equation is derived for the calculation of the gross composition of lignins based on the yields of methoxy-substituted aromatic acids obtained on permanganate oxidation of lignins with methylated phenolic groups. The equation could also be used for the calculation of the phenolic content in a lignin sample based on permanganate oxidation data, provided that such data are available for a similar lignin sample with known phenolic content. Literature data for milled wood lignin from spruce are used to exemplify the calculations
Quantitative analysis of lignins based on permanganate oxidation (Preliminary calculations)
Quantitative lignin analysis based on permanganate oxidation
Aromatic acids obtained on permanganate oxidation of pretreated (cleavage of ethers and alkylation of phenolic groups) lignins offer a possibility to estimate the amounts of differently substituted aromatic units in lignins. An equation is derived to simplify the calculation of the gross composition of lignins based on the yields of methoxy-substituted aromatic acids obtained on permanganate oxidation of lignins with methylated phenolic groups. The fact that only phenolic groups yield degradation acids makes it possible, under certain conditions, to use the equation for the estimation of the phenol content in a lignin sample
THE STRUCTURE AND CONFORMATION OF LIGNIN AS JUDGED BY X-RAY CRYSTALLOGRAPHIC INVESTIGATIONS OF LIGNIN MODEL COMPOUNDS: ARYLGLYCEROL β-SYRINGYL ETHERS
Structural elements of the arylglycerol β-syringyl ether type are very frequent in hardwood lignins. A variety of crystalline dimeric lignin models representing different diastereomeric forms of structural elements in lignin of this type have been studied using X-ray crystallography. Bond distances and bond angles in the model compounds are in all probability nearly identical with those of the corresponding structural elements in lignins. Special attention was paid to the geometry of the β-O-syringyl linkage, since the reactivity of this linkage is of particular interest in connection with pulping reactions. The crystal structures of the model compounds suggest that two types of conformations are predominating; in both of them the aromatic rings are separated by ca. 4.5 Ă
(maximal distance 4.9-5 Ă
). Based on X-ray crystallographic data from four compounds a sequence of units (5 aromatic rings, 8 chiral C-atoms) attached to each other by β-syringyl ether linkages was constructed. The appearance of the resulting oligomer illustrates that stereoisomerism can be expected to influence the shape of the lignin molecules to a great extent
THE STRUCTURE AND CONFORMATION OF LIGNIN AS JUDGED BY X-RAY CRYSTALLOGRAPHIC INVESTIGATIONS OF LIGNIN MODEL COMPOUNDS: ARYLGLYCEROL ïą-SYRINGYL ETHERS
Structural elements of the arylglycerol ïą-syringyl ether type are very frequent in hardwood lignins. A variety of crystalline dimeric lignin models representing different diastereomeric forms of structural elements in lignin of this type have been studied using X-ray crystallography. Bond distances and bond angles in the model compounds are in all probability nearly identical with those of the corresponding structural elements in lignins. Special attention was paid to the geometry of the ïą-O-syringyl linkage, since the reactivity of this linkage is of particular interest in connection with pulping reactions. The crystal structures of the model compounds suggest that two types of conformations are predominating; in both of them the aromatic rings are separated by ca. 4.5 Ă
(maximal distance 4.9-5 Ă
). Based on X-ray crystallographic data from four compounds a sequence of units (5 aromatic rings, 8 chiral C-atoms) attached to each other by ïą-syringyl ether linkages was constructed. The appearance of the resulting oligomer illustrates that stereoisomerism can be expected to influence the shape of the lignin molecules to a great extent