Machine strength grading of structural timber is based upon relationships between so called indicating properties (IPs) and bending strength. However, such relationships applied on the market today are rather poor. In this paper, new IPs and a new grading method resulting in more precise strength predictions are presented. The local fibre orientation on face and edge surfaces of wooden boards was identified using high resolution laser scanning. In combination with knowledge regarding basic wood material properties for each investigated board, the grain angle information enabled a calculation of the variation of the local MOE in the longitudinal direction of the boards. By integration over cross-sections along the board, an edgewise bending stiffness profile and a longitudinal stiffness profile, respectively, were calculated. A new IP was defined as the lowest bending stiffness determined along the board. For a sample of 105 boards of Norway spruce of dimension 45 9 145 9 3,600 mm 3 , a coefficient of determination as high as 0.68-0.71 was achieved between this new IP and bending strength. For the same sample, the coefficient of determination between global MOE, based on the first longitudinal resonance frequency and the board density, and strength was only 0.59. Furthermore, it is shown that improved accuracy when determining the stiffness profiles of boards will lead to even better predictions of bending strength. The results thus motivate both an industrial implementation of the suggested method and further research aiming at more accurately determined board stiffness profiles. Bestimmung der Biegefestigkeit von Schnittholz und der Variation der Biegesteifigkeit in Brettlängsrichtung in

Crimean-Congo hemorrhagic fever (CCHF) is a potentially fatal disease caused by a tick-borne virus in the family Bunyavridae. The disease occurs in parts of Africa, Asia, Middle East, and Eastern Europe. During recent years, an increasing number of human CCHF cases have been diagnosed in Iran, but very little information is available on the prevalence and genetic diversity of CCHFV in Iran. In the present study, CCHF virus (CCHFV) isolates from nine Iranian patients infected during 2002 were examined genetically. Nucleotide sequencing of the S- and M-segments, encoding the nucleocapsid protein (NP) and the glycoproteins, respectively, revealed that the different isolates were related closely to each other with nucleotide sequence identities exceeding 98% for both S- and M-segments. Phylogenetic analysis of partial S-segment nucleotide sequences showed that the viruses clustered along with strains from Pakistan and Madagascar in one distinct lineage. Phylogenetic analysis also demonstrated that the Iranian isolates examined in this study and the previously published CCHFV strain ArTeh193-3 clustered into different genetic groups, indicating that at least two genetic lineages of CCHFV could be co-circulating in Iran.

This paper deals with the development of models for twist in structural timber. Twist was measured on 240 studs of Norway spruce (Picea abies). Several material parameters were also measured, such as spiral grain angle, shrinkage in all three directions, annual ring width and density. Twist in the studs was measured at four different times at different moisture contents. The amount of twist correlated well with the moisture content and was reversible throughout several moisture changes. When the moisture content decreased, the twist increased and vice versa. About 50% of the variation in twist could be explained by a single parameter, i.e. the average growth ring curvature. All studs with severe twist were cut with its centroid within a radius of 75 mm from the pith. A statistical analysis of the data shows that growth ring curvature and spiral grain angle together explained about 70% of the variation in twist. Other parameters, such as shrinkage strains, density and ring width, did not increase predictability. When using a model developed by Stevens and Johnston (1960), about 66% of the variation in twist could be explained. The model also explained twist quantitatively well. The model included curvature of the growth ring, spiral grain angle and the tangential shrinkage strain. Verwerfung von Fichtenschnittholz. Teil 2. Simulation der Verdrehung Diese Arbeit behandalt dia Entwicklung von Modellon fu Èr die Verdrehung in Schnittholz. Die Verdrehung wurde gemessen an 240 Fichtenkantho Èlzern (Picea abies). Mehrere Materialeigenschaften wurden ebenfalls gemessen, und zwar: Faserwinkel, Schwinden in drei Richtungen, Jahrringbreite und Dichte. Die Verdrehung der Kantho Èlzer wurde zu vier verschiedenen Zeitpunkten bei unterschiedlichen Feuchtegraden gemessen. Das Ausmaû der Verdrehung war gut korreliert mit der Feuchte. Mit abnehmender Feuchte stieg die Verdrehung und umgekehrt. Rund 50% der Verdrehungswerte sind durch einen einzigen Parameter erkla Èrt, na Èmlich die Jahrringkru Èmmung. Bei allen Kantho Èlzern mit starker Verdrehung lag die Mittelachse innerhalb eines Abstandes von 75 mm von der Markro Èhre. Die statistische Analyse ergab, daû Jahrringkru Èmmung und Faserwinkel zusammen ca. 70% der Variation der Verdrehung erkla Èren. Andere Parameter wie Schwindspannungen, Dichte und Jahrringbreite erho Èhten die Vorhersagbarkeit nicht. Mit Hilfe des Modells von Stevens und Johnson (1960) konnten rund 66% der Verdrehung erkla Èrt werden. Dieses Modell lieferte auch zufriedenstellende quantitative Ergebnisse. Beru Ècksichtigt werden dabei Jahrringkru Èmmung, Faserwinkel und tangentiale Schwindspannung.

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