The Wood-Water-Formaldehyde System

The physical interactions of the wood-water-formaldehyde system are reviewed.Swelling data at 20 and 40 C (68 and 104 F) are presented which show that Douglas-fir and red alder wood shrink relative to pure water in low concentration water-formaldehyde solutions, and swell in higher concentration solutions ultimately to 18% by volume for a 24% (weight) solution of formaldehyde at 40 C (104 F).The composite sorption isotherms of the wood-water-formaldehyde system are complex. There is seen, however, an initial relative increase in water concentration of the sorbed phase, followed by a general decrease of water concentration for most of the other concentrations studied. The reasons for this are not known

Effect of pH and Buffering Capacity of Wood on The Gelation Time of Urea-Formaldehyde Resin

The pH and buffering capacity for water extract of the heartwood and sapwood of ten hardwoods and nine softwoods were determined. pH values ranged from 4.00 to 5.86 for hardwood and 4.02 to 5.82 for softwood. The gelation time for a urea-formaldehyde resin as affected by wood flour for each wood was determined. Analysis shows that a strong correlation between gel time of wood flour and either pH or acid buffering capacity of water extract exists

The Areal Extent and Hydraulic Continuity of Perched Ground Water in the Vicinity of the Pantex Plant

Groundwater contamination at the Pantex Plant is currently restricted to a perched aquifer(s) above the regional Ogallala aquifer water table. Therefore, the areal extent and hydraulic continuity of this unit are critical factors in the overall hydrologic characterization required for the design of effective remediation activities. Another important question is determining whether any privately owned domestic wells are producing from the perched aquifer(s) in areas downgradient from and hydrologically connected to known or possible contaminated areas on the Pantex Plant. It should be noted, however, that a continuous saturated zone is not the only scenario by which point-source and non-point-source contaminants could migrate. All recharging groundwater that is perched will eventually move through the fine-grained, low-permeability zone that underlies the perched aquifer(s) and resume a downward track to the Ogallala aquifer. In addition, the results of this study clearly illustrate areas where there is no perched aquifer(s), and thus there may be no perching layer, within the boundary of the Pantex Plant. In these areas where a perching layer is absent, there will be no retarding effect created by the perched aquifer(s) on the vertical movement of recharge to the Ogallala aquifer.Bureau of Economic Geolog

KH 15D: A Spectroscopic Binary

We present the results of a high-resolution spectroscopic monitoring program of the eclipsing pre-main-sequence star KH 15D that reveal it to be a single-line spectroscopic binary. We find that the best-fit Keplerian model has a period P = 48.38 days, which is nearly identical to the photometric period. Thus, we find the best explanation for the periodic dimming of KH 15D is that the binary motion carries the currently visible star alternately above and below the edge of an obscuring cloud. The data are consistent with the models involving an inclined circumstellar disk, as recently proposed by Winn et al. (2004) and Chiang & Murray-Clay (2004). We show that the mass ratio expected from models of PMS evolution, together with the mass constraints for the visible star, restrict the orbital eccentricity to 0.68 < e < 0.80 and the mass function to 0.125 < Fm < 0.5 Msun.Comment: 8 pages, 4 figures, 3 tables, accepted for publication in September AJ. Discussion of rotational velocity deferred to Hamilton, et al. (2004, in prep). Previously reported vsini value in error; Replaced Table 3 with new Figure 3; Added new Table 2 showing individual radial velocities w.r.t. each reference star; Fixed typo in Figure

Updated bathymetry of the Anegada-Jungfern Passage complex and implications for Atlantic inflow to the abyssal Caribbean Sea

Recent bathymetric, hydrographic and direct velocity measurements indicate that a previously unexplored deep passage in the northeastern Caribbean Sea may play a significant role in the abyssal ventilation of this basin. The Anegada-Jungfern Passage complex has long been recognized as the sole pathway for deep Atlantic inflow to the eastern Caribbean. The Anegada Passage (sill depth 1915 m) connects the Atlantic Ocean with the small Virgin Islands Basin, while Jungfern Passage (sill depth 1815 m) connects the latter with the large and deep Venezuela Basin comprising the eastern third of the Caribbean Sea. In the region of Jungfern Passage recent bathymetric measurements reveal additional, shallower routes for Atlantic inflow at depths between 1710 and 1630 m. Despite the relatively shallow controlling depths of these passages, direct measurements of velocity and watermass properties reveal an active inflow of water of Atlantic origin. Bathymetric and other oceanographic observations indicate that the previously unexplored Grappler Channel (sill depth 1710 m; located just west of Jungfern Passage) is responsible for up to 20% of the total inflow to the abyssal Caribbean from the mid-depth Atlantic (about 0.2 Sv)

Torus Palatinus: A New Anatomical Correlation with Bone Density in Postmenopausal Women

The observation that subjects who have a striking oral exostosis, called torus palatinus, also tended to have normal or high bone densities prompted us to examine an unselected population referred for bone density assessment for a possible correlation with torus palatinus. Subjects referred from community physicians had a visual examination of the open mouth to estimate the size of any torus palatinus (0 for none/ trace to 5 for very large) before undergoing a bone density measurement by dual energy x-ray absortiometry. Bone density T- and z-scores were correlated with the size of each subject’s torus palatinus. Torus size groups were also correlated with other variables affecting bone density. About 20% of 370 postmenopausal female subjects,\u3e90% Caucasian, had a moderate to large torus palatinus. Regression correlations for torus size were modest, but significantly related to T- and z-scores of lumbar vertebrae and left hip (P \u3c 0.01 for each). Differences due to medication, body mass index, smoking, parity, and several other factors that affect bone density did not diminish the relation to torus size. This study shows a small, but significant, positive relation for postmenopausal, Caucasian women between bone mineral density and torus size after controlling for several variables known to affect bone density were examined. Torus prominence, in association with other factors, can be considered in decisions for testing bone density in otherwise normal postmenopausal women

NPHC and MGC Sororities and Fraternities as Spaces of Activism within Predominantly White Institutions

This study explored how Students of Color within National Pan-Hellenic Council and Multicultural Greek Council sororities and fraternities engaged in activism and in what ways this involvement connected to their membership. Using a qualitative critical narrative approach, we examined the journeys of ten participants. Findings unpack ways participants engaged in activism and resistance aimed at educating individuals and increasing awareness of societal injustices, addressing inequities through service, and inciting disruption and cultivating institutional and societal level change

Technical Assessment of the National Full Scale Aerodynamic Complex Fan Blades Repair

This report describes the principal activities of a technical review team formed to address National Full Scale Aerodynamic Complex (NFAC) blade repair problems. In particular, the problem of lack of good adhesive bonding of the composite overwrap to the Hyduliginum wood blade material was studied extensively. Description of action plans and technical elements of the plans are provided. Results of experiments designed to optimize the bonding process and bonding strengths obtained on a full scale blade using a two-step cure process with adhesive primers are presented. Consensus recommendations developed by the review team in conjunction with the NASA Ames Fan Blade Repair Project Team are provided along with lessons learned on this program. Implementation of recommendations resulted in achieving good adhesive bonds between the composite materials and wooden blades, thereby providing assurance that the repaired fan blades will meet or exceed operational life requirements