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Some methods to reduce residual stress inside logs have been reported, although the conditions for stress relaxation are not yet clarified. Our study using precise experiments revealed that residual stress relaxation occurs only when both heat and moisture exist inside the logs. We then determined the heating time and temperature required to relax the residual stress inside the logs. Short air-drying treatments did not relax residual stress even though free water in the logs was greatly reduced. The residual stress of the 33-h 80°C-heated bolts was relaxed, whereas that of the 48-h 70°C-heated bolts was not. As for the influence of treatment time, bolts heated at 100°C were relaxed after 18 h of treatment. The 13-h heated bolts did not show any relaxation. Therefore, residual stress relaxation occurred rapidly owing to the thermomechanical change of the individual wood components comprising the cell wall. The moisture content inside all the bolts was much higher than the fiber saturation point. This is because relaxation occurs only when the heating temperature is maintained above 80°C for a particular duration of treatment.

Steaming and heating as pretreatments before log sawing reduce the negative effects of growth strain (GS). The object of this work was to study the reduction of GS in logs of Dipteryx panamensis from a fast-growth plantation using steaming and heating treatments and evaluate the effects on the lumber quality. According to the results, the maximum temperature in the center of the log was approximately 90[degrees]C after 24 hours for both treatments. GS decreased after heating and steaming. The average value of GS for three treatments was 2,085.61 microdeformation units ([MU][EPSILON]) before the treatment, decreasing to average value to 1,692.14 [MU][EPSILON] after the treatments. This reduction in turn produced a reduction of crook due to sawing measured in logs and semilogs and a decrease in the values and incidence of crook, bow, twist, and split. Similarly, color parameters (L*, a*, and b*) were statistically affected by the treatment, except for parameter L* in sapwood. In general, wood darkening was observed. Lastly, both treatments applied to D. panamensis logs showed few differences in GS, in crook due to sawing measured in logs and semilogs, and in the values and incidence of crook, bow, twist, and split. Therefore, both treatments achieved GS reduction in D. panamensis lumber., Growth strain (GS) in trees has been widely studied concerning its causes (Archer 1987) and management applied to the trees (Kubler 1988). GS is related to mechanical strain permanently borne [...]

Abstract [Sr.sup.2+] was chemically grafted onto the hydroxyl position of bacterial cellulose. Fourier transform infrared and UV-Vis spectroscopy were used to evaluate the chemical bonding of the modified bacterial cellulose [...]

2019 JAN 31 (NewsRx) -- By a News Reporter-Staff News Editor at Women's Health Weekly -- Investigators publish new report on Kidney Diseases and Conditions - Chronic Kidney Disease. According [...]

SUNDAY, JUNE 16, 1996 8:00 AM-5:00 PM WSFA: DIGITAL CELLULAR TELEPHONES: SYSTEMS AND TECHNOLOGIES Digital cellular and cordless telephones operating in the 900 MHz to 2 GHz frequency band are [...]

Background. The Cervex-Brush (Rovers, The Netherlands; Unimar, Wilton, Conn) is a cervical cytologic sampling device used to simultaneously collect endocervical and ectocervical cells. The optimal method for using this device to collect cervical epithelial cells for a Papanicolaou smear has not been described in the medical literature. Methods. Using the Cervex-Brush, Papanicolaou smears were collected from 516 women in a prospective randomized study to evaluate five different clockwise rotation techniques: 180[degrees] rotation of the brush, 360[degrees], 720[degrees], 1080[degrees], and 1800[degrees]. The Bethesda System of classifying Papanicolaou smears was used to report cytologic results. Endocervical cell presence as an indicator of smear adequacy was quantitated from 0 to 4(+). Results. As the number of rotations was increased, the number of endocervical cells collected also increased (P [greater than] .05). Abnormal cells were found in 22.3% of the smears obtained by rotating the brush 1080[degrees] and 1800[degrees]. This was compared with abnormal cells found in 8.2%, 4.5%, and 11.5% of the smears collected by rotating the brush 180[degrees], 360[degrees], and 720[degrees], respectively (P [greater than] .001). Two smears that identified high-grade squamous intraepithelial lesions were collected using the 1800[degrees] rotation. Unsatisfactory smears were obtained in 39 (7.5%) of the 516 smears. The percentage of slides containing hemorrhagic artifact was greatest (16.4%) in the 1800[degrees] rotation group, but the likelihood of the Papanicolaou smear being considered unsatisfactory was not increased (P [greater than] .05). Conclusions. Using a clockwise 1800[degrees] rotation of the Cervex-Brush to obtain a Papanicolaou smear maximized the collection of endocervical cells, detected the greatest percentage of abnormal cells, and did not statistically exceed the acceptable limit for hemorrhagic artifact. Key words. Papanicolaou smear; cytology; cervix dysplasia; cervix neoplasms. J Fam Pract 1992; 34:276-280., The purpose of the Papanicolaou smear is to identify premalignant or malignant disease occurring in the transformation zone of the cervix. Adequate sampling of cervical epithelial cells from the transformation [...]