• Journal of the Korean Wood Science and Technology
• /
• v.31 no.1
• /
• pp.61-70
• /
• 2003

The size distribution of the free water paths between earlywood and latewood for six species in the heartwood of softwoods was estimated from the amount of dehydrated free water under various centrifugal fields, such as 2,200, 3,300, 4,800 and 6,900 rpm. The centrifugal method is based on the concept that water movement occurs by the balance of centrifugal force and water potential by meniscus. Water stops where the pressure differential is zero. In the centrifugal field, only two factors affect water movement in wood, that is, centrifugal force and water potential. Also, the water permeability was evaluated from the relationship between the water saturation ratio after the centrifugal treatment and the measure of water potential in specimen. The results showed that Cryptpmeria japonica had clear peaks at 0.70 ㎛ in earlywood and at 0.50 ㎛ in latewood. Tsuga sieboldii and Larix kaemferi had peaks at 0.50 and 0.30 ㎛ in both earlywood and latewood, respectively. Abies firma showed peaks at 0.70 ㎛ in earlywood and at 0.30 ㎛ in latewood. The water permeability of earlywood was higer than that of latewood for all softwoods except Pseudotsuga menziesii.

• Tuberculosis and Respiratory Diseases
• /
• v.43 no.4
• /
• pp.571-578
• /
• 1996

Background : Long abscess is an accumulation of pus within a destroyed portion of the lung. Antibiotic therapy and postural drainge has proven to be an effective method of treatment for the majority of patients with pyogenic lung abscess. When medical therapy fails, thoracotomy and pulmonary resection are the current therapies. empyema is pus in the pleural space, and this term is deserved for effusions on which the Gram stain of the pleural fluid is positive. Initially, such collection may be drained via chest tribe. Recently, in patients who are judged to be unsuitable for surgery are in poor condition, percutaneous drainage using pig-tail catheter has been performed. We report out experience with 10 cases of lung abscess and 23 cases of empyema who were treated by percutaneous pit-tail catheter drainage. Subjects and Methods : Our study included 10 patients with lung abscess and 23 patients with empyema who were treated by percutaneous pig-tail catheter drainage, from January, 1990, to May, 1996, at Hanyang University then a pig-tail catheter was inserted into the abscess or the site of empyema under fluoroscopic and ultrasonograpic guidance. Following aspiration, the catheter was sutured into the skin, and connected to the suction tip. Catheter drainage was discontinued when the abscess of empyema was resolved in radiologically and clinically. Results : There were 2 cases of lung abscess caused by Staphylococcus aureus and Klebsiella pneumoniae and 14 cases of empyema caused by M. tuberculosis. The others were unknown. The duration of drainage was 1-2 weeks in 7 cases of lung abscess and 14 cases of empyema. In the 29 of 33 patients, percutaneous drainage were carried out successfully 20 of the 29 Gases rapidly improved. Conclusion : Percutaneous drainge is effective and relatively saute for management of lung abscess or empyema refractory to medical therapy or poor candidates for surgical treatment.