3D laboratory-scale soilbed for assessment of fate and transport of explosive-related compounds in soils under variable environmental conditions

2006 ◽  
Author(s):  
Angel A. Anaya ◽  
Ingrid Padilla
Keyword(s):  
Environmental Conditions ◽  
Fate And Transport ◽  
Laboratory Scale ◽  
Related Compounds

Munitions-Related Technology Demonstrations at Ordnance Reef (HI-06), Hawaii

2012 ◽  
Vol 46 (1) ◽  
pp. 63-82 ◽  
Author(s):  
Geoffrey Carton ◽  
J. C. King ◽  
R. Josh Bowers
Keyword(s):  
Department Of Defense ◽  
Focal Point ◽  
Fate And Transport ◽  
Disposal Site ◽  
Remotely Operated Vehicle ◽  
Recovery System ◽  
Underwater Navigation ◽  
Commercial Off The Shelf ◽  
Navigation Equipment ◽  
Related Compounds

AbstractDevelopment of methods and technologies to characterize sites with underwater military munitions (UWMM) and respond to UWMM where the risks posed to human health or the environment or explosive hazards are unacceptable is underway. Department of Defense Military Munitions Sea Disposal Site Hawaii (HI-06), referred to locally as Ordnance Reef, is off Oahu’s leeward coast. This site has become the focal point for research on UWMM. Past studies found that the site presents no immediate danger to public safety. The location and water depth at this site present advantages for UWMM research and development.Promising technologies demonstrated at Ordnance Reef (HI-06) include those for munitions recovery, at-sea demilitarization, nondestructive testing, and explosives detection. Studies on fate and transport of munitions-related compounds and corrosion are ongoing.Among these technologies are the Remotely Operated Underwater Munitions Recovery System (ROUMRS) and the Explosive Hazard Demilitarization System (EHDS). Both are assemblages of commercial off-the-shelf components, and each is housed in a standard 6-m International Organization for Standardization (ISO) shipping container and can be operated on a barge.ROUMRS consists of a remotely operated vehicle, manipulators, an interface between a precision GPS, and underwater navigation equipment used during recovery of UWMM. The system also transports recovered UWMM for treatment. The EHDS consists of a portable X-ray unit to allow positive identification of recovered munitions, remotely operated wet band saws to cut recovered munitions to expose their explosive fill, and low-temperature ovens to treat the exposed explosives, making the remaining material safe for recycling.

Interpreting unique colloidal response of TiO2 nanomaterials to controlled sonication for understanding of their assembly configuration in water

2016 ◽  
Vol 16 (6) ◽  
pp. 1768-1775
Author(s):  
Siyang Wu ◽  
Hyeok Choi
Keyword(s):  
Environmental Conditions ◽  
Aquatic Environment ◽  
Fate And Transport ◽  
Intrinsic Property ◽  
Engineered Nanomaterials ◽  
Time Resolved ◽  
Tio2 Particles ◽  
Transport Behavior ◽  
Tio2 Nanomaterials

It is important to determine the assembly configuration of engineered nanomaterials (ENMs) because assembly configuration influences their fate and transport behavior in the aquatic environment. Aggregated particles are more subject to segregation upon changes of environmental conditions (and vice versa) than agglomerated particles. As a strategic tool for investigating the time-resolved reversible segregating and assembling behavior of ENMs and thus estimating their assembly configuration, a controlled sonication process was proposed. It was hypothesized that the unique colloidal response of ENMs to sonication, with respect to changes in size, might be their intrinsic property associated with assembly configuration. As a model ENM, three different TiO2 particles with unique properties (commercial P-25 and UV 100 and home-made (HM) TiO2) were examined with programmed sonication processes under various environmental settings. When they were dispersed in water, all TiO2 particles tested obviously assembled to form much larger clusters. Size of P-25 decreased immediately upon sonication and did not change under the subsequent quiescence step while sizes of UV 100 and HM gradually decreased and then slowly recovered back to their initial sizes. The trend was generally observed in all conditions tested. The unique colloidal response of TiO2 could be explained by its properties associated with assembly configuration.

Effects of time of day, moisture stress, and frosting on the alkaloid content of Phalaris tuberosa

1972 ◽  
Vol 23 (4) ◽  
pp. 611 ◽  
Author(s):  
JD Williams
Keyword(s):  
Environmental Conditions ◽  
Leaf Tissue ◽  
Moisture Stress ◽  
Time Of Day ◽  
Alkaloid Content ◽  
Experimental Results ◽  
Field Conditions ◽  
Field Observations ◽  
Slight Effect ◽  
Related Compounds

Time of day had a slight effect on the level of N,N-dimethylated indolealkylamines in leaf tissue of plants of Phalaris tuberosa L. grown under controlled environmental conditions, and a somewhat larger effect on plants grown under field conditions. The alkaloid content was not affected significantly by moderate increases in moisture stress, but severe wilting caused an increase in the alkaloid content. The immediate regrowth from plants previously stressed had a higher alkaloid content than regrowth from unstressed plants. Severe moisture stress also caused an increase in certain related compounds, as yet unidentified. Frosting increased the alkaloid content more in plants receiving adequate nitrogen, and even more in plants grown at 21/16°C compared with plants grown at 15/10°. Changes in alkaloid content are discussed in relation to field observations and previous experimental results on the toxicity of P. tuberosa pastures to sheep.

Study of Cysts Biometry and Hatching Percentage of the Brine Shrimp Artemia salina (Linnaeus, 1758) from the Sebkha of Sidi El Hani (Tunisia) According to Successive Generations

2020 ◽  
Vol 21 (1) ◽  
pp. 41-46
Author(s):  
Imene Sellami ◽  
Hachem Ben Naceur ◽  
Adnane Kacem
Keyword(s):  
Environmental Conditions ◽  
Brine Shrimp ◽  
Significant Variation ◽  
Dunaliella Salina ◽  
Adult Stage ◽  
Artemia Salina ◽  
Laboratory Scale ◽  
The Third ◽  
Hatching Percentage ◽  
Successive Generations

Artemia salina cysts harvested from the Sebkha of Sidi El Hani were hatched and cultivated in the laboratory. The obtained nauplii were acclimated at 90 ppt and fed with Dunaliella salina microalgae until the adult stage called generation 1 (G1) was reached. Ten couples were isolated and acclimated in the same conditions. Observations of the offspring lasted for a maximum of 60 days. Cysts obtained from G1 were collected and counted. Cyst diameter, chorion thickness and hatching percentage were established. Nauplii obtained from G1 were labelled G2. The third (G3) and the fourth (G4) generations were studied similarly. A significant variation of untreated cyst diameter between G1 (234.7±14.1 µm) and the subsequent generations, notably G3 (210.9±14 µm) were registered. Decapsulated cyst diameter delayed significantly from 218.5±12.8 (G1) to 190.8±10.1 (G3). The chorion thickness ranged between 8.1 (G1) and 10.5 (G2). Therefore, an interesting boost of untreated cysts hatching percentage was observed from 69±2.3% (G1) to 76±3.7% (G4). These results highlighted the variability of cyst diameter across successive generations, even cultivated under laboratory scale. An improvement of hatching quality was detected when environmental conditions became favorable.

Photochemical analyses of ozone and related compounds under various environmental conditions

2012 ◽  
Vol 47 ◽  
pp. 446-458 ◽  
Author(s):  
Sang-Keun Song ◽  
Yoo-Keun Kim ◽  
Zang-Ho Shon ◽  
Jae-Yong Ryu
Keyword(s):  
Environmental Conditions ◽  
Related Compounds
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