Mitigation of oxygen decline in fjords by freshwater injection

The exchange of water masses between deep fjords and the open ocean is commonly constrained by a topographical barrier called the sill. While fjord water above the sill depth communicates relatively freely with the open ocean, water below the sill depth is caught inside the fjord basin. This basin water may remain stagnant in deep fjords for many successive years. During these periods, the biological consumption of dissolved oxygen is larger than the supply of new oxygen, and the fjord basin might experience hypoxia and even anoxia. Such deoxygenation is natural but can be amplified by warming and human activities involving supplies of organic matter and other nutrients. Here, we use a general circulation model to explore how deoxygenation can be mitigated by injecting fresh water into the fjord basin. The freshwater injection causes density reduction of the basin water with subsequent water exchange and oxygenation. Our results suggest that the basin water of Masfjorden, a 480 m deep fjord with a basin volume of 4 × 109 m3, can avoid deoxygenation with a continuous freshwater injection of 0.05 m3 s−1. We conclude that freshwater injection might be an efficient tool to mitigate the deoxygenation of fjord basins.publishedVersio

Production of XeO * in a CW microwave discharge

A low-power CW microwave discharge at 2.45 GHz was used to produce XeO * excimer molecules. It was found that a total gas pressure between 5 and 20 Torr, absorbed power of about 20–100 W, and an oxygen-to-xenon ratio of 1∶100 maximized the XeO( 1 S− 1 D) green emission at 5200 to 5600 Å. The XeO * emission appeared in the cooler parts of the discharge near the containment tube walls and in the electric field nodes of the TM 012 resonant mode.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45480/1/11090_2005_Article_BF01023916.pd

Psychometric properties of the Norwegian translation of the Tinnitus Handicap Inventory (THI-NOR)

Objective: To assess the psychometric properties of a Norwegian translation of the Tinnitus Handicap Inventory (THI-NOR). Design: A survey was sent by post to patients referred with tinnitus as their main complaint to an audiology department. Patients completed a Norwegian version of the Tinnitus Handicap Inventory (THI-NOR), a Norwegian translation of two revised subscales of the Abbreviated profile of hearing aid benefit (APHAB), the General Health Questionnaire (GHQ-12) as well as questionnaires measuring coping expectancies (TOMCATS) and neuroticism (EPI). Study sample: Ninety-nine persons with tinnitus. Results: No associations were found between THI-scores or pure-tone audiometry, gender or age. The proposed subscales of the original THI were not formed by responses from responders. The total scale shows good psychometric properties. Significant correlations were found between distress as measured by the GHQ-12, coping expectancies as measured by TOMCATS and neuroticism as measured by EPI and THI scores. Conclusions: THI-NOR has psychometric properties similar to those of the Danish translation (THI-DK), from which it was adapted, and to the original THI. THI-NOR seems to be a valid measure of the impact of tinnitus on a person’s everyday life. Findings show that the suggested subscales of the questionnaire should be interpreted with caution

Selective and high-yield synthesis of higher fullerenes

Fullerenes have been prepared by de are synthesis with graphite (anode) rods containing light elements such as B, Si, or Al in a series of concentrations. Furthermore, the influence of mixing N-2(g) with He(g) on the yield of higher fullerenes has been addressed, For each type of experiment, the relative fullerene yields are obtained from the relative peak areas in surface analysis by laser ionization-mass spectrometry (SALI-MS) spectra and the absolute yield of C-60 and C-70 from calibrated HPLC; the relative yields in SALI-MS represent closely the nascent distribution in the primary soots. We determine the approximate absolute yields of higher fullerenes, for which extinction coefficients are not yet available for HPLC analysis, by scaling the absolute C-60 and C-70 yields with the relative concentrations from SALI-MS. The most prominent increased higher fullerene yield was obtained with a 1% B-doped graphite rod with a 2:100 volume mixture of Nz(g):He(g); the absolute yield of C-60 was reduced from 8.85% to 2.75%, and the yield of higher fullerenes such as C-78 and C-84 was increased by a factor of 2 over the pure C, pure He(g) case. We conclude that using a B-doped graphite rod and mixing in small amounts of Nz(g) into He(g) enhances both the absolute and relative yields of higher fullerenes

MAGNETIC SEPARATION OF GDC2 ENCAPSULATED IN CARBON NANOPARTICLES

Single crystal particles of alpha-GdC2 have been encapsulated into carbon polyhedral shells by the carbon arc-discharge technique. These particles range in size from 20 to 50 nm and are paramagnetic in nature. The phase and stoichiometry of these crystals have been determined using a combination of techniques, such as X-ray diffraction and high-resolution electron microscopy. As reported for alpha-LaC2 earlier, the crystal structure of bulk alpha-GdC2 is also tetragonal, and it is metallic and undergoes hydrolysis. However, the encapsulation of the nanoscale crystals in carbon shells prevents their hydrolysis indefinitely. These nanometer-sized particles, which can be preferentially extracted using powerful magnetic fields, may have useful applications in several fields of science

INFRARED STUDY OF VIBRATIONAL PROPERTY AND POLYMERIZATION OF C-60 AND C-70 UNDER PRESSURE

Infrared spectra were measured for solid C60 and C70 to 7 GPa under hydrostatic or quasi-hydrostatic pressure at room temperature. Some vibrational modes showed negative or insensitive dependence of frequency on pressure, suggesting destabilization of C60 and C70 molecules by compression. In solid C60 new absorption bands gradually grew with increasing pressure in association with an intensity decrease of the original bands. These spectral changes were interpreted in terms of polymerization of C60 molecules. Polymerized molecules recovered at ambient pressure were converted back to the monomer by thermal annealing at 473 K

High-flux solar photon processes

This study was commissioned by the National Renewable Energy Laboratory (NREL) for the purpose of identifying high-flux photoprocesses that would lead to beneficial national and commercial applications. The specific focus on high-flux photoprocesses is based on the recent development by NREL of solar concentrator technology capable of delivering record flux levels. We examined photolytic and photocatalytic chemical processes as well as photothermal processes in the search for processes where concentrated solar flux would offer a unique advantage. 37 refs