Long-Term Permeability Tests Using Leachate on a Compacted Clayey Liner Material

2009 ◽  
pp. 397-397-8 ◽  
Author(s):  
H-Y Fang ◽  
JC Evans
Keyword(s):  
Liner Material

Use of organophilic clay in sand-bentonite as a barrier to diesel fuel

1996 ◽  
Vol 33 (5) ◽  
pp. 705-719 ◽  
Author(s):  
Brigitte EJ Boldt-Leppin ◽  
Moir D Haug ◽  
John V Headley
Keyword(s):  
Hydraulic Conductivity ◽  
Diesel Fuel ◽  
Petroleum Products ◽  
Hydraulic Performance ◽  
Laboratory Research ◽  
Liner Material ◽  
Desiccation Cracking ◽  
Organophilic Clay ◽  
Infiltration Tests

A laboratory research program was conducted to evaluate the long-term hydraulic performance of sand–bentonite liners augmented with organophilic clay and permeated with diesel fuel. This program was also designed to establish guidelines for the incorporation of organophilic clay in sand–bentonite liners. The study involved three areas of testing. The first was to characterize the materials. The second was to evaluate various combinations of materials and preparation techniques through hydraulic conductivity tests. The third area involved unconfined infiltration tests. The primary hydraulic conductivity testing was broken into three phases. These investigated the hydraulic conductivity of organophilic sand–bentonite liners using various percentages of organophilic clay and evaluated the hydraulic performance of these specimens when permeated with distilled water and diesel fuel. Hydraulic conductivity was measured in specially designed low gradient, low effective stress stainless-steel triaxial permeameters. The results of this test program indicated that small percentages (3%) of organophilic clay in a sand–bentonite liner material could effectively be used to avoid desiccation cracking in a liner permeated with petroleum products. High percentages (7.5%) of organophilic clay in a sand–bentonite mixture resulted in a liner permeable to water, but reduced permeability to diesel fuel. Key words: organophilic clay, diesel fuel, bentonite, liners, hydraulic conductivity, triaxial permeability testing.

scholarly journals Shrinkage Characteristics of Boulder Marl as Sustainable Mineral Liner Material for Landfill Capping Systems

2018 ◽  
Vol 10 (11) ◽  
pp. 4025 ◽  
Author(s):  
Steffen Beck-Broichsitter ◽  
Horst Gerke ◽  
Rainer Horn
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Shrinkage Stress ◽  
Undisturbed Soil ◽  
Liner Material ◽  
Size Dependent ◽  
Undisturbed Soil Cores ◽  
Shrinkage Behavior

The soil shrinkage behavior of mineral substrates needs to be considered for engineering long-term durable mineral liners of landfill capping systems. For this purpose, a novel three-dimensional laser scanning device was coupled with (a) a mathematical-empirical model and (b) in-situ tensiometer measurements as a combined approach to simultaneously determine the shrinkage behavior of a boulder marl, installed as top and bottom liner material at the Rastorf landfill (Northern Germany). The shrinkage behavior, intensity, and geometry were determined during a drying experiment with undisturbed soil cores (100 cm3) from two soil pits; the actual in-situ shrinkage was also determined in 0.2, 0.5, 0.8, and 1.0 m depth by pressure transducer tensiometer measurements during a four-year period. The volume shrinkage index was used to describe the pore size dependent shrinkage tendency and it was classified as low (4.9%) for the bottom liner. The in-situ matric potentials in the bottom liner ranged between −100 and −150 hPa, even during drier periods, thus, the previously highest observed drying range (pre-shrinkage stress) with values below −500 hPa and −1000 hPa was not exceeded. Therefore, the hydraulic stability of the bottom liner was given.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

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