Christina Gustafsson

Use of Tablet Tensile Strength Adjusted for Surface Area and Mean Interparticulate Distance to Evaluate Dominating Bonding Mechanisms

In this study, tablet tensile strength has been adjusted for tablet surface area and the average distance between particles in compacts of different materials. The aim of the study was to evaluate the feasibility of using this concept to assess the dominating interparticulate bonding mechanisms. Adjustment of the tensile strength for both tablet surface area and mean pore radius gave similar bonding strength values for materials bonding mainly by weak distance forces (crystalline lactose, sucrose, and microcrystalline cellulose) almost independently of compaction pressure. However, particle size and other factors may still affect the compensated strength values. The bond strength was much higher and more varied for materials bonding also with solid bridges (potassium chloride, sodium chloride, and possibly also sodium bicarbonate and amorphous lactose). For these materials, particle size and compaction pressure had a substantial effect on the bond strength. It is probably the formation of continuous bridges between adjacent particles that is important in these materials rather than the surface properties and the average distance between particles positioned at some distance from each other. Hence, adjusting the tensile strength of compacts does not necessarily reflect all the dominating factors responsible for interparticulate bonding. Nonetheless, adjustment for tablet surface area and mean pore radius allowed discrimination between different dominating interparticulate bonding mechanisms in these compacted materials.

Examensarbetet inom lärarutbildningen – En analys i relation till Högskolelagens mål

The point of departure is the prominent article of the Higher Education Act – 1 chap. 9 § – where the overall objects of higher education are drawn up. This is the intention of state for the individual student and graduate student. A central premise for this article is that teacher training students have attained these objects when they finish their education and conduct an undergraduate dissertation. In this article the data material discussed consists of the assessment of 30 undergraduate dissertations conducted during autumn semester 2004. The performances showed great discrepancy in relation to the higher education objects. A discussion of the outcome of the study in relation to some frame factors and international studies is included. The most important aspect of this problem area is the students’ difficulty to develop a scholarly approach during the education process. One conclusion is that actors (teachers, supervisors, etc.) at the university/college have to be more distinct and more eager to explain scientific work in rela tion to everyday teaching- and learning activities. Another conclusion is that there is a great demand to deepen the knowledge of the policy documents in higher education and relate such research to scientific studies of curriculum theory.

Temaintroduktion: Högre utbildning i ljuset av högskolelagen – exemplet lärarutbildning.

Sedan mer än tio år tillbaka har Högskoleverket gjort olika typer av regelbundna utvärderingar av svensk högskoleutbildning. Utvärderingarna kompletteras av granskningarna i anslutning till ansökningar om universitetsstatus, vetenskapsområde och examensrätter. Inom alla dessa aktiviteter har kvalitet och kvalitetssäkring varit honnörsord. Ibland har det gått så långt att man nästan kunnat uppfatta orden som mantra, dvs. en form av besvärjelse som med automatik skulle innebära något positivt. Men man borde oftare fråga sig vad kvalitet är. Birgitta Giertz har i en genomgång kunnat konstatera att det är svårt att generellt beskriva vad kvalitet inom högre utbildning är. En del vill gärna göra det till en subjektiv angelägenhet; kvalitet är avhängigt betraktaren. Andra ger generella definitioner. En konsekvens av detta är att det i allmänhet finns olika visioner av programkvalitet och sättet som utvärderaren förstår kvalitet på bestämmer vilken kvalitet som redovisas i en utvärdering. Inom högskolan är för mig ett givet kvalitetskriterium Högskolelagens portalparagraf (1 kap. 9 §):

Cellulose powder fromCladophora sp. algae

The surface are and crystallinity was measured on a cellulose powder made from Cladophora sp. algae. The algae cellulose powder was found to have a very high surface area (63.4 m2/g, N2 gas adsorption) and build up of cellulose with a high crystallinity (≈100%, solid state NMR). The high surface area was confirmed by calculations from atomic force microscope imaging of microfibrils from Cladophora sp. algae.