The effects of heat treatment on some mechanical properties of laminated black pine (Pinus nigra)
Black pine (Pinus nigra) has high industrial usage potential and large plantation in Turkey. Larch wood was treated with heat to determine its mechanical properties, such as bending strength and pressure and order to determine its adhesion strength. Laminating adhesives are used for the construction of polyvinyl acetate and polyurethane. Heat treatment was applied to the samples at 100-150°C for 4 h in drying oven. In the result of the experiments, heat treated samples give better results due to temperature increase. 
 
   
 
 Key words: Heat treatment, bending strength, compression strength, bonding strength, black pine.
Heat treatment on keruing and light red meranti: The effect of heat exposure at different levels of temperature on bending strength properties
Heat treatment on timbers is a process of applying heat to modify and equip the timbers with new improvised characteristics. It is environmental friendly compared to the common practice of treating timber by chemical preservatives. Malaysian hardwood timbers namely Keruing and Light Red Meranti which are in green condition were heat treated at temperature 150°C, 170°C, 190°C and 210°C, in a specially designed electronic furnace within one hour duration. The objectives were to determine the effect of heat treatment on bending strength properties of heat treated timbers in terms of Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) and to examine the significance changes at each temperature level. Untreated samples for each species were used as a control sample. The results indicated that the bending strength properties for both species of timbers were affected by the heat exposure. Both MOE and MOR values for heat treated Keruing were increased when subjected to the temperature levels at 150°C, 170°C and 190°C except at 210°C. Heat treated Light Red Meranti shows the same pattern of increment on its MOE and MOR values after exposure to heat at three temperature levels applied and the values dropped at 210°C. However, for both of species, even though there were decrement occurred at 210°C, the value is still higher compared to the control sample. The increments of MOE and MOR values are an indicator that heat treatment had successfully improvised the bending strength properties of these two species of hardwood timber.
Percussion marks on bone surfaces as a new diagnostic of hominid behaviour
Since stone tool cut marks and carnivore tooth marks were first described systematically on Plio-Pleistocene archaeological bone1,2, bone surface modification has played a prominent role in interpreting early archaeological site formation and hominid behaviour3–15. Here we introduce a new class of bone surface modification, which we call percussion marks. Percussion marks were produced during experimental breakage of marrow bones, and occur as pits or grooves impressed on a bone's surface by natural protrusions on the granitic hammerstone and anvil used. Although percussion marks can superficially mimic carnivore tooth marks, they nonetheless are closely associated with hammerstone impact notches and show consistent micromorphological features which distinguish them from tooth marks and other classes of bone surface modification. Given indications of prehistoric hammer-stone breakage of marrow bones1,7, an awareness of percussion marks is critical for accurately identifying the biological agents of bone modification at archaeological sites and provides a new diagnostic of carcass processing by hominids.