Machinability of Minor Wooden Species before and after Modification with Thermo-Vacuum Technology.

The influence of the thermal modification process on wood machinability was investigated with four minor species of low economic importance. A set of representative experimental samples was machined to the form of disks with sharp and dull tools. The resulting surface quality was visually evaluated by a team of experts according to the American standard procedure ASTM D-1666-87. The objective quantification of the surface quality was also done by means of a three dimensions (3D) surface scanner for the whole range of grain orientations. Visual assessment and 3D surface analysis showed a good agreement in terms of conclusions. The best quality of the wood surface was obtained when machining thermally modified samples. The positive effect of the material modification was apparent when cutting deodar cedar, black pine and black poplar in unfavorable conditions (i.e., against the grain). The difference was much smaller for an easy-machinability specie such as Italian alder. The use of dull tools resulted in the worst surface quality. Thermal modification has shown a very positive effect when machining with dull tools, leading to a relevant increment of the final surface smoothness.

Functional predictors of exertional dyspnea, 6-min walking distance and HRCT fibrosis score in idiopathic pulmonary fibrosis.

BACKGROUND: Exertional dyspnea and exercise incapacity are the most prominent and disabling symptoms and the main contributors to health-related quality of life in patients with idiopathic pulmonary fibrosis (IPF). OBJECTIVES: There are no comprehensive studies on pulmonary function tests (PFTs), dyspnea, exercise capacity and radiographic scores in IPF. We therefore sought to investigate the functional variables that can predict dyspnea, exercise capacity and disease extent in IPF. METHODS: Thirty-four patients with IPF according to the ATS/ERS criteria underwent PFTs, Medical Research Council (MRC) dyspnea scoring, 6-min walking distance (6-MWD) and radiographic evaluation of fibrosis (HRCT score). RESULTS: The 6-MWD (% pred.) was more impaired than PFTs. Residual volume (RV) showed the best correlation with the extent of fibrosis (r = -0.67, p = 0.0001) and, together with the alveolar-arterial gradient for O(2) [DeltaP(A - a)O(2)], was an independent predictor of disease extent (R(2) = 0.44). PFTs showed significant though weak correlations with MRC score and 6-MWD. According to the regression analysis, DL(CO) and the HRCT fibrosis score were independent predictors of dyspnea, though they explained only 28% of the overall variance. FEV(1) and DeltaP(A - a)O(2) were independent predictors of 6-MWD (R(2) = 0.31). CONCLUSIONS: PFTs and lung volumes in particular are closely related to the HRCT score, a measure of the extent of IPF. The correlation of dyspnea score and 6-MWD to PFTs is limited, due to the complexity of mechanisms leading to exercise limitation in IPF. Therefore dyspnea and exercise performance are largely independent indices and should be followed together with PFTs and HRCT score in order to better assess the status and progress of IPF patients.