Groundwater suppression and diversion structures applied to closed shallow land burial trenches

International Nuclear Information System (INIS)

Davis, E.C.; Melroy, L.A.; Huff, D.D.

1984-01-01

Shallow depth to groundwater, surface drainage, and subsurface flow during storm events are major environmental concerns of low-level radioactive waste management operations in humid regions. At two waste disposal sites within the Oak Ridge National Laboratory (ORNL), groups of closed trenches have experienced these problems and have been shown to collect and hold intratrench water with seasonal fluctuations ranging from 1 to 2 m. In an attempt to correct these water-related problems, Solid Waste Storage Area Four (SWSA-4) was equipped in September 1975 with asphalt-lined drainage ways designed to prevent reinfiltration of storm drainage from the 13.8 ha upslope catchment. At 49-Trench Area of SWSA-6 the entire 0.44 ha trench area was capped with a bentonite clay cover in 1976. These early attempts at hydrologic isolation have not corrected the water problems. In September 1983, two similarly designed engineered drainage projects were initiated at the disposal sites. The SWSA-4 project was designed to divert surface runoff around the trench area and drain a portion of the shallow subsurface flow which originates upslope of the site. The second project, a passive French drain constructed in SWSA-6, was aimed strictly at suppressing the site water table thus preventing its intersection with the bottoms of disposal trenches. Post-construction monitoring for performance evaluation has shown that the water table in the 49-trench area has been suppressed to a depth >4.9 m below the ground surface over 50% of the site with a maximum drawdown of 4 m at the drains deepest point. The SWSA-4 project evaluation is just being completed and data show that 56 +/- 15% of the Winter-Spring 1984 runoff was diverted around SWSA 4. As a result, a 44% reduction in 90 Sr flux was calculated from observed discharges and a previously established relation between flow rate and 90 Sr concentration

Burial trench dynamic compaction demonstration at a humid site

International Nuclear Information System (INIS)

Spalding, B.P.

1985-01-01

This task has the objective of determining the degree of consolidation which can be achieved by dynamic compaction of a closed burial trench within a cohesive soil formation. A seven-year-old burial trench in Solid Waste Storage Area (SWSA) 6 of Oak Ridge National Laboratory (ORNL) was selected for this demonstration. This 251 m 3 trench contained about 80 Ci of mixed radionuclides, mostly 90 Sr, in 25 m 3 of waste consisting of contaminated equipment, dry solids, and demolition debris. Prior to compaction, a total trench void space of 79 m 3 was measured by pumping the trench full of water with corrections for seepage. Additional pre-compaction characterization included trench cap bulk density (1.68 kg/L), trench cap permeability (3 x 10 -7 m/s), and subsurface waste/backfill hydraulic conductivity (>0.01 m/s). Compaction was achieved by repeatedly dropping a 4-ton steel-reinforced concrete cylinder from heights of 4 to 8 m using the whipline of a 70-ton crane. The average trench ground surface was depressed 0.79 m, with some sections over 2 m, yielding a surveyed volumetric depression which totaled to 64% of the measured trench void space. Trench cap (0 to 60 cm) bulk density and permeability were not affected by compaction indicating that the consolidation was largely subsurface. Neither surface nor airborne radioactive contamination were observed during repeated monitoring during the demonstration. Dynamic compaction was shown to be an excellent and inexpensive (i.e., about $20/m 2 ) method to collapse trench void space, thereby hastening subsidence and stabilizing the land surface. 15 refs., 10 figs., 3 tabs

Design improvements on shallow-land burial trenches for disposing of low-level radioactive waste

International Nuclear Information System (INIS)

Takamura, E.S.; Salsman, J.M.

1984-01-01

The lack of success of closed low-level radioactive waste disposal sites has prompted the federal government to increase regulation of these facilities. In order to meet these increased requirements, several waste trench improvements are necessary. These improvements to the trench include sandy-clay caps, compacted sandy-clay bottoms, in-place geophysical instruments and vadose zone sampling equipment, and concrete sidewalls. These design improvements presented in this paper should increase the containment of the radionuclides by decreasing the waste contact with infiltrating groundwater. The design improves on the monitoring and sampling methods for detecting radionuclides transported through the leachate or gas effluent streams. 13 references, 4 figures

'Dodo' and 'Baby Bear' Trenches

Science.gov (United States)

2008-01-01

NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 11 (June 5, 2008), the eleventh day after landing. It shows the trenches dug by Phoenix's Robotic Arm. The trench on the left is informally called 'Dodo' and was dug as a test. The trench on the right is informally called 'Baby Bear.' The sample dug from Baby Bear will be delivered to the Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA. The Baby Bear trench is 9 centimeters (3.1 inches) wide and 4 centimeters (1.6 inches) deep. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Paleoseismic Trenching on 1939 Erzincan and 1942 Niksar-Erbaa Earthquake Surface Ruptures, the North Anatolian Fault (Turkey)

Science.gov (United States)

Akyuz, H. S.; Karabacak, V.; Zabci, C.; Sancar, T.; Altunel, E.; Gursoy, H.; Tatar, O.

2009-04-01

Two devastating earthquakes occurred between Erzincan (39.75N, 39.49E) and Erbaa, Tokat (40.70N, 36.58E) just three years one after another in 1939 and 1942. While 1939 Erzincan earthquake (M=7.8) ruptured nearly 360 km, 1942 Erbaa-Niksar earthquake (M=7.1) has a length of 50 km surface rupture. Totally, more than 35000 citizens lost their lives after these events. Although Turkey has one of the richest historical earthquake records, there is no clear evidence of the spatial distribution of paleoevents within these two earthquake segments of the North Anatolian Fault. 17 August 1668 Anatolian earthquake is one of the known previous earthquakes that may have occurred on the same segments with a probable rupture length of more than 400 km. It is still under debate in different catalogues, if it was ruptured in multiple events or a single one. We achieved paleoseismic trench studies to have a better understanding on the recurrence of large earthquakes on these two faults in the framework of T.C. DPT. Project no. 2006K120220. We excavated a total of 8 trenches in 7 different sites. While three of them are along the 1942 Erbaa-Niksar Earthquake rupture, others are located on the 1939 Erzincan one. Alanici and Direkli trenches were excavated on the 1942 rupture. Direkli trench site is located at the west of Niksar, Tokat (40.62N, 36.85E) on the fluvial terrace deposits of the Kelkit River. Only one paleoevent could be determined from the structural relationships of the trench wall stratigraphy. By radiocarbon dating of charcoal sample from above the event horizon indicates that this earthquake should have occurred before 480-412 BC. The second trench, Alanici, on the same segment was located between Erbaa and Niksar (40.65N, 36.78E) at the western boundary of a sag-pond. While signs of two (possible three) earthquakes were identified on the trench wall, the prior event to 1942 Earthquake is dated to be before 5th century AD. We interpreted this to have possibility of

Subsurface moisture regimes and tracer movement under two types of trench-cap designs for shallow land burial sites

International Nuclear Information System (INIS)

Perkins, B.A.; Cokal, E.J.

1986-03-01

The Los Alamos work has focused on proper design of shallow land burial (SLB) sites in arid and semiarid regions and on applying corrective measures to existing sites. One of the most important design features affecting the probability of movement of radionuclides in SLB sites is the type of trench cap placed over the waste. The cap influences such interdependent parameters as erosion, water infiltration and percolation, and biointrusion. To obtain experimental data for arid and semiarid sites, two different designs of trench caps, one with topsoil underlain with a cobble/gravel biobarrier and one with topsoil underlain with crushed tuff, were compared with respect to (1) seasonal changes in volumetric soil water content, and (2) downward migration of tracers emplaced directly below each type of trench cap. The causes for the large differences in concentrations found in this experiment need to be investigated further. Problems in environmental modeling and monitoring of arid and semiarid SLB sites because of heterogeneities in the soil profiles and their implications for SLB waste management need to be better understood. More work in trench-cap design and its influence on the many pathways available for mobilization is needed

Design of homogeneous trench-assisted multi-core fibers based on analytical model

DEFF Research Database (Denmark)

Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

2016-01-01

We present a design method of homogeneous trench-assisted multicore fibers (TA-MCFs) based on an analytical model utilizing an analytical expression for the mode coupling coefficient between two adjacent cores. The analytical model can also be used for crosstalk (XT) properties analysis, such as ...

'Dodo-Goldilocks' Trench Elevation Map

Science.gov (United States)

2008-01-01

This color-coded elevation map shows the 'Dodo-Goldilocks' trench dug by the Robotic Arm on NASA's Phoenix Mars Lander. The trench, originally two separate trenches nicknamed 'Dodo' (left) and 'Goldilocks' (right), became one after further digging on the 18th Martian day, or Sol 18, of the mission (June 12, 2008). The trench is 7 to 8 centimeters (2.7 to 3 inches) at its deepest (blue). Because the terrain itself is inclined at a 14-degree angle, the highest areas (pink) are about 20 centimeters (7.8 inches) above the lowest areas. The trench is 22 centimeters (8.7 inches) wide and 35 centimeters (13.8 inches) long. Its deepest portion is closest to the lander. This picture was taken by Phoenix's Surface Stereo Imager on Sol 19 (June 13, 2008). The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Surface radiological investigation of Trench 5 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Goff, D.D.

1991-08-01

A surface radiological investigation of areas encompassing Trench 5 on the Oak Ridge Reservation (ORR) was conducted from May 1990 through November 1990. This survey was led by the author, assisted by various members of the Measurement Applications and Development (MAD) group of the Health and Safety Research Division (HASRD) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the investigation was to determine the presence, nature, and extent of surface radiological contamination at Trench 5, the Homogeneous Reactor Experiment fuel wells, and surrounding areas. Based on the data obtained in the field, interim corrective measures were recommended to limit human exposure to radioactivity and to minimize insult to the environment. It should be stressed that this project was not intended to be a complete site characterization but rather to be a preliminary investigation into the potential contamination problem that might exist as a result of past operations at Trench 5

Initial SVE Well Testing for the A-Area Miscellaneous Rubble Pile (ARP) Trenches Area

International Nuclear Information System (INIS)

RIHA, BRIAN

2004-01-01

The A-Area Miscellaneous Rubble Pile (ARP) is a 5.9 acre unit located at the southern end of A/M Area at the Savannah River Site (SRS). Disposal activities at ARP began in the early 1950s. The exact dates of operation and material disposed in the unit remain unknown. Within the ARP exists a smaller, approximately 2 acre, sub unit identified as the Trenches Area. The Trenches Area is dominated by a T-shaped trench (approximately 50 feet wide) containing 8 to 12 feet of ash material. This T-shaped trench will be referred to as the ARP Trench. Vegetation has been removed from the Trenches Area and a lower permeability earthen cover now covers the ARP Trench. The ARP active soil vapor extraction (ASVE) remediation system consists of seven extraction wells and twelve monitoring wells that were pushed into the vadose zone of the ARP Trench. The remediation system was designed based on the pre-design study conducted in 2002. The purpose of the initial soil vapor extraction (SVE) well testing was to verify the integrity and functionality of the nineteen wells installed in the ARP Trench. The well integrity was evaluated based on the flow rate, vacuum, and indication that soil gas and not surface air was pulled from the well. Soil gas was defined as gas with levels of carbon dioxide (CO2) above ambient concentrations (400-700 ppmv). Volatile organic compound (VOC) concentrations were measured at each well to determine the initial distribution of the contamination. In addition, the subsurface vacuum distribution was measured around each extraction well as a relative measure of the influence of each well

Characterization of deep nanoscale surface trenches with AFM using thin carbon nanotube probes in amplitude-modulation and frequency-force-modulation modes

International Nuclear Information System (INIS)

Solares, Santiago D

2008-01-01

The characterization of deep surface trenches with atomic force microscopy (AFM) presents significant challenges due to the sharp step edges that disturb the instrument and prevent it from faithfully reproducing the sample topography. Previous authors have developed AFM methodologies to successfully characterize semiconductor surface trenches with dimensions on the order of tens of nanometers. However, the study of imaging fidelity for features with dimensions smaller than 10 nm has not yet received sufficient attention. Such a study is necessary because small features in some cases lead to apparently high-quality images that are distorted due to tip and sample mechanical deformation. This paper presents multi-scale simulations, illustrating common artifacts affecting images of nanoscale trenches taken with fine carbon nanotube probes within amplitude-modulation and frequency-force-modulation AFM (AM-AFM and FFM-AFM, respectively). It also describes a methodology combining FFM-AFM with a step-in/step-out algorithm analogous to that developed by other groups for larger trenches, which can eliminate the observed artifacts. Finally, an overview of the AFM simulation methods is provided. These methods, based on atomistic and continuum simulation, have been previously used to study a variety of samples including silicon surfaces, carbon nanotubes and biomolecules

Color View 'Dodo' and 'Baby Bear' Trenches

Science.gov (United States)

2008-01-01

NASA's Phoenix Mars Lander's Surface Stereo Imager took this image on Sol 14 (June 8, 2008), the 14th Martian day after landing. It shows two trenches dug by Phoenix's Robotic Arm. Soil from the right trench, informally called 'Baby Bear,' was delivered to Phoenix's Thermal and Evolved-Gas Analyzer, or TEGA, on Sol 12 (June 6). The following several sols included repeated attempts to shake the screen over TEGA's oven number 4 to get fine soil particles through the screen and into the oven for analysis. The trench on the left is informally called 'Dodo' and was dug as a test. Each of the trenches is about 9 centimeters (3 inches) wide. This view is presented in approximately true color by combining separate exposures taken through different filters of the Surface Stereo Imager. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

'Dodo-Goldilocks' Trench Dug by Phoenix

Science.gov (United States)

2008-01-01

This color image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on the 19th day of the mission, or Sol 19 (June 13, 2008), after the May 25, 2008, landing. This image shows one trench informally called 'Dodo-Goldilocks' after two digs (dug on Sol 18, or June 12, 2008) by Phoenix's Robotic Arm. The trench is 22 centimeters (8.7 inches) wide and 35 centimeters (13.8 inches) long. At its deepest point, the trench is 7 to 8 centimeters (2.7 to 3 inches) deep. White material, possibly ice, is located only at the upper portion of the trench, indicating that it is not continuous throughout the excavated site. According to scientists, the trench might be exposing a ledge, or only a portion of a slab, of the white material. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

The special trench design near the through silicon vias (TSVs) to reduce the keep-out zone for application in three-dimensional integral circuits

International Nuclear Information System (INIS)

Liao, M-H

2013-01-01

Trench structure is designed and used to release process induced stress, resulting from the different material thermal expansion coefficients, in three-dimensional integral circuits (3DICs). The stress in the designed trench structure is measured by atomic force microscope Raman technique experimentally, and simulated by the full process simulation model. With the help of this simulation model, the optimized trench structure near the copper-filled TSV is designed and reported. The experimental data demonstrate that the tensile stress near the TSV can be reduced from 600 MPa to 150 MPa and the corresponding keep-out zone (KOZ) can also be decreased ∼4 times with the designed trench structure having a depth of 10 µm and spacing distance of 8 µm to the TSV. This work provides one potential solution to release process induced stress for real application of 3DICs. (paper)

Phoenix Trenches

Science.gov (United States)

2008-01-01

[figure removed for brevity, see original site] Annotated Version [figure removed for brevity, see original site] Left-eye view of a stereo pair [figure removed for brevity, see original site] Right-eye view of a stereo pair This image is a stereo, panoramic view of various trenches dug by NASA's Phoenix Mars Lander. The images that make up this panorama were taken by Phoenix's Surface Stereo Imager at about 4 p.m., local solar time at the landing site, on the 131st, Martian day, or sol, of the mission (Oct. 7, 2008). In figure 1, the trenches are labeled in orange and other features are labeled in blue. Figures 2 and 3 are the left- and right-eye members of a stereo pair. For scale, the 'Pet Donkey' trench just to the right of center is approximately 38 centimeters (15 inches) long and 31 to 34 centimeters (12 to 13 inches) wide. In addition, the rock in front of it, 'Headless,' is about 11.5 by 8.5 centimeters (4.5 by 3.3 inches), and about 5 centimeters (2 inches) tall. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Field evaluation of two shallow land burial trench cap designs for long-term stabilization and closure of waste repositories at Los Alamos, New Mexico

International Nuclear Information System (INIS)

Nyhan, J.; Drennon, B.; Hakonson, T.

1989-02-01

The results from several field experiments on methods to control soil erosion, biointrusion, and water infiltration were used to design and test a burial site cover which improves the ability of the disposal site to isolate the wastes. The performance of the improved cover design in managing water and biota at the disposal site was compared with a more conventional design widely used in the industry. The conventional trench cover design consists of 15 cm of sandy loam topsoil over 75 cm of sandy silt backfill, whereas the improved trench cover design consists of 75 cm of topsoil over a minimum of 25 cm of gravel and 90 cm of river cobble. Each plot was lined with an impermeable liner to allow for mass balance calculation of water dynamics and contains hydrologic tracer ions (iodide and bromide) to demonstrate movement of water through the various zones of the trench cap. Cesium was emplaced beneath the trench cap to indicate root penetration through the trench cap, observed by sampling plant samples collected on the plots and assaying them for cesium. The field data are summarized and discussed in terms of its usefulness for waste management decisions. 67 refs., 44 figs., 4 tabs

Trench reactor: an overview

International Nuclear Information System (INIS)

Spinrad, B.I.; Rohach, A.F.; Razzaque, M.M.; Sankoorikal, J.T.; Schmidt, R.S.; Lofshult, J.; Ramin, T.; Sokmen, N.; Lin, L.C.

1988-01-01

Recent fast, sodium-cooled reactor designs reflect new conditions. In nuclear energy these conditions are (a) emphasis on maintainability and operability, (b) design for more transparent safety, and (c) a surplus of uranium and enrichment availability that eases concerns about light water reactor fueling costs. In utility practice the demand is for less capital exposure, short construction time, smaller new unit sizes, and low capital cost. The PRISM, SAFR, and integral fast reactor (IFR) concepts are responses to these conditions. Fast reactors will not soon be deployed commercially, so more radical designs can be considered. The trench reactor is the product of such thinking. Its concepts are intended as contributions to the literature, which may be picked up by one of the existing programs or used in a new experimental project. The trench reactor is a thin-slab, pool-type reactor operated at very low power density and- for sodium-modest temperature. The thin slab is repeated in the sodium tank and the reactor core. The low power density permits a longer than conventional core height and a large-diameter fuel pin. Control is by borated steel slabs that can be lowered between the core and lateral sodium reflector. Shutdown is by semaphore slabs that can be swung into place just outside the control slabs. The paper presents major characteristics of the trench reactor that have been changed since the last report

Trench mouth

Science.gov (United States)

... gingivae). The term trench mouth comes from World War I, when this infection was common among soldiers " ... mouth include: Emotional stress Poor oral hygiene Poor nutrition Smoking Throat, tooth, or mouth infections Trench mouth ...

Trench infiltration for managed aquifer recharge to permeable bedrock

Science.gov (United States)

Heilweil, V.M.; Watt, D.E.

2011-01-01

Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

Slurry walls and slurry trenches - construction quality control

International Nuclear Information System (INIS)

Poletto, R.J.; Good, D.R.

1997-01-01

Slurry (panel) walls and slurry trenches have become conventional methods for construction of deep underground structures, interceptor trenches and hydraulic (cutoff) barriers. More recently polymers mixed with water are used to stabilize the excavation instead of bentonite slurry. Slurry walls are typically excavated in short panel segments, 2 to 7 m (7 to 23 ft) long, and backfilled with structural materials; whereas slurry trenches are fairly continuous excavations with concurrent backfilling of blended soils, or cement-bentonite mixtures. Slurry trench techniques have also been used to construct interceptor trenches. Currently no national standards exist for the design and/or construction of slurry walls/trenches. Government agencies, private consultants, contractors and trade groups have published specifications for construction of slurry walls/trenches. These specifications vary in complexity and quality of standards. Some place excessive emphasis on the preparation and control of bentonite or polymer slurry used for excavation, with insufficient emphasis placed on quality control of bottom cleaning, tremie concrete, backfill placement or requirements for the finished product. This has led to numerous quality problems, particularly with regard to identification of key depths, bottom sediments and proper backfill placement. This paper will discuss the inspection of slurry wall/trench construction process, identifying those areas which require special scrutiny. New approaches to inspection of slurry stabilized excavations are discussed

STUDY OF ELECTRICAL CHARACTERISTIC OF NEW P-TYPE TRENCHED UMOSFET

OpenAIRE

Akansha Ephraim*, Neelesh Agrawal, Anil Kumar, A.K. Jaiswal

2017-01-01

In this paper p-type trenched UMOSFET was designed without super junction and constructed like any other conventional MOSFET. Characteristic curve was studied between drain current verses drain voltage and drain current verses gate voltage. The trench was designed under TCAD simulation tool Silvaco software using etching process. The specific channel length of the p-type UMOSFET has been concentrated as 0.9 microns. The device structures are designed using Silvaco Athena and characteristics w...

Fully engineered shallow trench design concepts for disposal of low and intermediate level radioactive waste

International Nuclear Information System (INIS)

Locke, J.

1984-09-01

In this report, the results of the reviews of design concepts, waste arisings and release mechanisms are described. The basic principles of radiological protection and the proposed strategy for land disposal in the UK are outlined. The essential features of engineered trenches are described with some discussion of the likely material choices and their influence on nuclide release. The radiological protection criteria adopted in this study is that the overall risk of serious health effects arising from any release of radioactivity from a shallow engineered trench should always be less than 10 -6 per annum, which corresponds to a received dose of 0.1 mSv/yr. This approach to radiological protection takes account of the two components of risk of health detriment to future generations; namely the probability that a release of radionuclides will occur and the probability that the subsequent radiation doses will give rise to deleterious effects. A compilation is presented of the waste streams and expected volumes and activities that may be designated for LAND 2 disposal and an initial estimate of the associated nuclide inventory is given. (author)

Color Image of Snow White Trenches and Scraping

Science.gov (United States)

2008-01-01

This image was acquired by NASA's Phoenix Mars Lander's Surface Stereo Imager on the 31st Martian day of the mission, or Sol 31 (June 26, 2008), after the May 25, 2008 landing. This image shows the trenches informally called 'Snow White 1' (left), 'Snow White 2' (right), and within the Snow White 2 trench, the smaller scraping area called 'Snow White 3.' The Snow White 3 scraped area is about 5 centimeters (2 inches) deep. The dug and scraped areas are within the diggiing site called 'Wonderland.' The Snow White trenches and scraping prove that scientists can take surface soil samples, subsurface soil samples, and icy samples all from one unit. Scientists want to test samples to determine if some ice in the soil may have been liquid in the past during warmer climate cycles. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver

Morning Frost in Trench Dug by Phoenix, Sol 113

Science.gov (United States)

2008-01-01

This image from the Surface Stereo Imager on NASA's Phoenix Mars Lander shows morning frost inside the 'Snow White' trench dug by the lander, in addition to subsurface ice exposed by use of a rasp on the floor of the trench. The camera took this image at about 9 a.m. local solar time during the 113th Martian day of the mission (Sept. 18, 2008). Bright material near and below the four-by-four set of rasp holes in the upper half of the image is water-ice exposed by rasping and scraping in the trench earlier the same morning. Other bright material especially around the edges of the trench, is frost. Earlier in the mission, when the sun stayed above the horizon all night, morning frost was not evident in the trench. This image is presented in approximately true color. The trench is 4 to 5 centimeters (about 2 inches) deep, about 23 centimeters (9 inches) wide. Phoenix landed on a Martian arctic plain on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

Trenching as an exploratory method

International Nuclear Information System (INIS)

Hatheway, A.W.; Leighton, F.B.

1979-01-01

The critical nature of siting nuclear power plants has led to increased emphasis on exploratory trenching. Trenching is the most definitive of all subsurface exploratory methods; it permits inspection of a continuous geologic section by both geologists and regulatory authorities and makes possible the preparation of a graphic log that delineates both obvious and subtle geologic features. About one of every two nuclear plant licensing efforts utilizes exploratory trenching. Many geologic hazards, such as ''capable'' faults, can be detected from trench exposures; they may otherwise remain undetected. Trenches must be judiciously located, survey-controlled, excavated safely and adequately shored, logged in detail, and properly diagnosed. Useful techniques of trench logging include thorough cleaning of the trench walls, teamwork between geologist and recorder, logging against a carefully surveyed baseline and vertical reference grid, and panoramic photography.Soils, including paleosols, and glacial and glaciofluvial deposits present some of the most difficult media to log. Trench logs must be thoroughly interpreted and correlated so that they document the geologic conditions governing suitability of the site. Age-determination techniques utilized in exploratory trenching include petrographic analyses, quartz inclusion studies, clay mineralogic analyses, and radiometric methods

Lateral-delivered organic matter boosts hadal bacterial abundance in the Mariana Trench: A hypothesis

Science.gov (United States)

Zhang, C.; Liu, H.; Lu, F.; Zou, L.; Tian, J.

2017-12-01

Hadal trenches are part of the least investigated biosphere on Earth due to the great challenge of sampling. Limited studies on microbiology by far have suggested that the hadalsphere hosts a heterotrophic microbial community that is likely fed by organic matter from surface-sinking biomass or re-suspended and laterally transported sediments. The uniqueness of trench environment and its potential role in global carbon sequestration entitle a detailed study on microbial-driven carbon cycle of the trench system. In this study, we conducted a vertical sampling of the microbial community and measured the environmental factors from the epipelagic zone down to the hadal zone at the Mariana Trench. 16S rRNA gene composition showed high stratification at the first 1000 meters below surface (mbs) but a nearly uniformed microbial community composition was observed at the abyssopelagic and the hadalpelagic water columns. The deep-sea bacteria were generally chemoheterotrophs and the majority of them were similar to those present at the ocean surface, suggesting influence of epipelagic primary production on deep sea bacterial communication at the trench location. Several deep-sea-enriched but surface-depleted bacteria could be characterized by potential degraders of polysaccharides and n-alkanes. Therefore, recalcitrant hydrocarbons or carbohydrates are likely important carbon sources supporting the deep-sea biosphere. In spite of consistent community composition, a remarkable increase in biomass of small-sized microbial aggregates was detected at 8727 mbs. Enhanced CDOM proportions in the trench imply intensified microbial activity in hadal water compared to the above water column, which agree with the notion of possible extra carbon input from lateral transportation of slope material. These observations extend our understanding in carbon cycle driven by metabolically diverse microorganisms at the trench and may shed light on the complexity of hadal biogeochemistry.

Report of exploratory trenching for the Decontamination and Waste Treatment Facility at Lawrence Livermore National Laboratory, Livermore, California

International Nuclear Information System (INIS)

Dresen, M.D.; Weiss, R.B.

1985-12-01

Three exploratory trenches, totaling about 1,300 ft in length were excavated and logged across the site of a proposed Decontamination and Waste Treatment Facility (DWTF), to assess whether or not active Greenville fault zone, located about 4100 ft to the northeast, pass through or within 200 ft of the site. The layout of the trenches (12-16 ft deep) was designed to provide continuous coverage across the DWTF site and an area within 200 ft northeast and southwest of the site. Deposits exposed in the trench walls are primarily of clay, and are typical of weakly cemented silty sand to sandy silt with the alluvial deposits in the area. Several stream channels were encountered that appear to have an approximated east-west orintation. The channel deposits consist of well-sorted, medium to coarse-grained sand and gravel. A well-developed surface soil is laterally continuous across all three trenches. The soil reportedly formed during late Pleistocene time (about 35,000 to 40,000 yr before present) based on soil stratigraphic analyses. A moderately to well-developed buried soil is laterally continuous in all three trenches, except locally where it has been removed by channelling. This buried soil apparently formed about 100,000 yr before present. At least one older, discontinuous soil is present below the 100,000-yr-old soil in some locations. The age of the older soil is unknown. At several locations, two discontinuous buried soils were observed between the surface soil and the 100,000-yr-old soil. Various overlapping stratigraphic units could be traced across the trenches providing a continuous datum of at least 100,000 yr to assess the presence or absence of faulting. The continuity of stratigraphic units in all the trenches demonstrated that no active faults pass through or within 200 ft of the proposed DWTF site

Surface radiological investigations of Trench 6 and low-level waste Line Leak Site 7.4b at the Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Uziel, M.S.; Tiner, P.F.; Williams, J.K.

1991-08-01

A surface radiological investigation of Trench 6 and low-level radioactive waste (LLW) Line Leak Site 7.4b was conducted in July and August 1989 and January 1990 by the Measurement Applications and Development Group, Oak Ridge National Laboratory. The purposes of this survey were (1) to determine the presence, nature, and extent of surface radiological contamination and (2) to recommend interim corrective action to limit human exposures to radioactivity and minimize the potential for contaminant dispersion. Highest surface gamma levels encountered during the survey (39 mR/h) were found just south of the asphalt covering LLW Line Leak Site 7.4b. Elevated surface gamma levels (measuring 28 to 560 μR/h) extended from this area to a width of 100 ft, westward 250 ft, and beyond the survey boundary. Beta-gamma levels up to 17 mrad/h measured on contact with the trunks of trees growing in the area southwest of Trench 6 suggest that three roots are reaching contamination deep within the ground. Since no gamma activity is associated with the trees or their leaves, the elevated beta levels are probably due to the uptake of residual 90 Sr originating from the documented seepage at the Trench 6/Leak Site 7.4b area. Beta activity present in the leaf litter and surface soil indicate that decaying leaves are depositing measurable contaminants on the ground surface. Recommendations for corrective actions are included. 7 refs., 20 figs., 3 tabs

An oxide filled extended trench gate super junction MOSFET structure

International Nuclear Information System (INIS)

Cai-Lin, Wang; Jun, Sun

2009-01-01

This paper proposes an oxide filled extended trench gate super junction (SJ) MOSFET structure to meet the need of higher frequency power switches application. Compared with the conventional trench gate SJ MOSFET, new structure has the smaller input and output capacitances, and the remarkable improvements in the breakdown voltage, on-resistance and switching speed. Furthermore, the SJ in the new structure can be realized by the existing trench etching and shallow angle implantation, which offers more freedom to SJ MOSFET device design and fabrication. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Trenching as a exploratory method

International Nuclear Information System (INIS)

Hatheway, A.W.; Leighton, F.B.

1979-01-01

The critical nature of siting nuclear power plants has led to increased emphasis on exploratory methods; it permits inspection of a continuous geologic section by both geologists and regulatory authorities and makes possible the preparation of a graphic log that delineates both obvious and subtle geologic features. About one of every two nuclear plant licensing efforts utilizes exploratory trenching. Many geologic hazards, such as ''capable'' faults, can be detected from trench exposures; they may otherwise remain undetected. Trenches must be judiciously located, survey-controlled, excavated safetly and adequately shored, logged in detail, and properly diagnosed. Useful techniques of trench logging include thorough cleaning of the trench walls, teamwork between geologist and recorder, logging against a carefully surveyed baseline and vertical reference grid, and panoramic photography. Soils, including paleosols, and glacial and glaciofluvial deposits present some of the most difficult media to log. Trench logs must be thoroughly interpreted and correlated so that they document the geologic conditions governing suitability of the site. Age-determination techniques utilized in exploratory trenching include petrographic analyses, quartz inclusion studies, clay mineralogic analyses, and radiometric methods

Process optimization of a deep trench isolation structure for high voltage SOI devices

International Nuclear Information System (INIS)

Zhu Kuiying; Qian Qinsong; Zhu Jing; Sun Weifeng

2010-01-01

The process reasons for weak point formation of the deep trench on SOI wafers have been analyzed in detail. An optimized trench process is also proposed. It is found that there are two main reasons: one is over-etching laterally of the silicon on the surface of the buried oxide caused by a fringe effect; and the other is the slow growth rate of the isolation oxide in the concave silicon corner of the trench bottom. In order to improve the isolation performance of the deep trench, two feasible ways for optimizing the trench process are proposed. The improved process thickens the isolation oxide and rounds sharp silicon corners at their weak points, increasing the applied voltage by 15-20 V at the same leakage current. The proposed new trench isolation process has been verified in the foundry's 0.5-μm HV SOI technology. (semiconductor devices)

First Dodo Trench with White Layer Visible in Dig Area

Science.gov (United States)

2008-01-01

These color images were taken by NASA's Phoenix Mars Lander's Stereo Surface Imager on the ninth Martian day of the mission, or Sol 9 (June 3, 2008). The images of the trench shows a white layer that has been uncovered by the Robotic Arm (RA) scoop and is now visible in the wall of the trench. This trench was the first one dug by the RA to understand the Martian soil and plan the digging strategy. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Preliminary design of a biological treatment facility for trench water from a low-level radioactive waste disposal area at West Valley, New York

Energy Technology Data Exchange (ETDEWEB)

Rosten, R.; Malkumus, D. [Pacific Nuclear, Inc. (United States); Sonntag, T. [New York State Energy Research and Development Authority, NY (United States); Sundquist, J. [Ecology and Environment, Inc. (United States)

1993-03-01

The New York State Energy Research and Development Authority (NYSERDA) owns and manages a State-Licensed Low-Level Radioactive Waste Disposal Area (SDA) at West Valley, New York. Water has migrated into the burial trenches at the SDA and collected there, becoming contaminated with radionuclides and organic compounds. The US Environmental Protection Agency issued an order to NYSERDA to reduce the levels of water in the trenches. A treatability study of the contaminated trench water (leachate) was performed and determined the best available technology to treat the leachate and discharge the effluent. This paper describes the preliminary design of the treatment facility that incorporates the bases developed in the leachate treatability study.

Morning Frost in Trench Dug by Phoenix, Sol 113 (False Color)

Science.gov (United States)

2008-01-01

This image from the Surface Stereo Imager on NASA's Phoenix Mars Lander shows morning frost inside the 'Snow White' trench dug by the lander, in addition to subsurface ice exposed by use of a rasp on the floor of the trench. The camera took this image at about 9 a.m. local solar time during the 113th Martian day of the mission (Sept. 18, 2008). Bright material near and below the four-by-four set of rasp holes in the upper half of the image is water-ice exposed by rasping and scraping in the trench earlier the same morning. Other bright material especially around the edges of the trench, is frost. Earlier in the mission, when the sun stayed above the horizon all night, morning frost was not evident in the trench. This image is presented in false color that enhances the visibility of the frost. The trench is 4 to 5 centimeters (about 2 inches) deep, about 23 centimeters (9 inches) wide. Phoenix landed on a Martian arctic plain on May 25, 2008. The mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

High Density Faraday Cup Array or Other Open Trench Structures and Method of Manufacture Thereof

Science.gov (United States)

Gilchrist, Kristin Hedgepath (Inventor); Bower, Christopher A. (Inventor); Stoner, Brian R. (Inventor)

2014-01-01

A detector array and method for making the detector array. The detector array includes a substrate including a plurality of trenches formed therein, and a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charged particles incident on respective ones of the collectors and to output from the collectors signals indicative of charged particle collection. In the detector array, adjacent ones of the plurality of trenches are disposed in a staggered configuration relative to one another. The method forms in a substrate a plurality of trenches across a surface of the substrate such that adjacent ones of the trenches are in a staggered sequence relative to one another, forms in the plurality of trenches a plurality of collectors, and connects a plurality of electrodes respectively to the collectors.

Detection and delineation of waste trenches by geophysical methods at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Selfridge, R.J.

1987-01-01

Detection and delineation of waste trenches at hazardous waste sites are needed before actual implementation of site corrective measures. In a field study conducted in Solid Waste Storage Area 4 (SWSA4) at Oak Ridge National Laboratory (ORNL), surface geophysical techniques were used to assist in the delineation of waste trenches. A magnetometer/gradiometer survey was used to detect ferrous metals buried at the site. An electromagnetic ground conductivity survey was used to measure the electrical conductivity of the subsurface and aided in supporting the magnetometer/gradiometer results. Results from the two techniques were complimentary and easily integrated into a final interpretation. The reliability, efficiency, and worker safety benefits of these techniques offer a nondestructive surface technique for locating buried waste trenches

300 Area Process Trenches Supplemental Information to the Hanford Contingency Plan (DOE/RL-93-75)

International Nuclear Information System (INIS)

R.A. Carlson

1997-01-01

The 300 Area Process Trenches are surface impoundments which were used to receive routine discharges of nonregulated process cooling water from operations in the 300 Area and dangerous waste from several research and development laboratories and the 300 Area Fuels Fabrication process. Discharges to the trenches ceased in 1994, and they were physically isolated in 1995. Remediation of the trenches is scheduled to begin during July 1997. Currently, there are no waste management activities required at the 300 Area Process Trenches and the unit does not present any significant hazards to adjacent units, personnel, or the environment. It is unlikely that any incidents presenting hazards to public health or the environment would occur at the 300 Area Process Trenches, however, during remediation, exposure, spill, fire, and industrial hazards will exist. This contingency plan addresses the emergency organization, equipment and evacuation routes pertinent to the process trenches during remediation

Benthic carbon mineralization in hadal trenches

DEFF Research Database (Denmark)

Wenzhofer, F.; Oguri, K.; Middelboe, M.

2016-01-01

Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consump...

A systematic study of BNL's 3D-Trench Electrode detectors

International Nuclear Information System (INIS)

Montalbano, A.; Bassignana, D.; Li, Z.; Liu, S.; Lynn, D.; Pellegrini, G.; Tsybychev, D.

2014-01-01

New types of silicon pixel detectors have been proposed because of the need for more radiation hard semiconductor devices for the high luminosity tracking detector upgrades at the Large Hadron Collider. A novel type of 3D Si pixel detectors is proposed, with each cell of the 3D-Trench Electrode pixel detector featuring a concentric trench electrode surrounding the central collecting column electrode. The pixel sensor is an array of those individual cells. Systematic 3D simulations using Silvacos TCAD programs have been carried out to study the characteristics of this novel 3D pixel design and to compare to the traditional 3D column electrode pixel design. The 3D simulations show a much lower depletion voltage and a more uniform electric field in the new 3D-Trench Electrode pixel detectors as compared to the traditional 3D column Electrode detectors. The first prototype 3D-Trench Electrode pixel detectors have been manufactured at the Centro Nacional De Microelectronica. Preliminary electrical measurements are discussed and charge collection efficiency measurements are presented

Magnetron target designs to improve wafer edge trench filling in ionized metal physical vapor deposition

International Nuclear Information System (INIS)

Lu Junqing; Yoon, Jae-Hong; Shin, Keesam; Park, Bong-Gyu; Yang Lin

2006-01-01

Severe asymmetry of the metal deposits on the trench sidewalls occurs near the wafer edge during low pressure ionized metal physical vapor deposition of Cu seed layer for microprocessor interconnects. To investigate this process and mitigate the asymmetry, an analytical view factor model based on the analogy between metal sputtering and diffuse thermal radiation was constructed. The model was validated based on the agreement between the model predictions and the reported experimental values for the asymmetric metal deposition at trench sidewalls near the wafer edge for a 200 mm wafer. This model could predict the thickness of the metal deposits across the wafer, the symmetry of the deposits on the trench sidewalls at any wafer location, and the angular distributions of the metal fluxes arriving at any wafer location. The model predictions for the 300 mm wafer indicate that as the target-to-wafer distance is shortened, the deposit thickness increases and the asymmetry decreases, however the overall uniformity decreases. Up to reasonable limits, increasing the target size and the sputtering intensity for the outer target portion significantly improves the uniformity across the wafer and the symmetry on the trench sidewalls near the wafer edge

Backfilling of trenches exposed to waves

DEFF Research Database (Denmark)

Hjelmager Jensen, Jacob; Fredsøe, Jørgen

1997-01-01

This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence......-closure. The backfilling process of trenches exposed to either waves or a steady current is of importance in relation to the implementation of pipelines in the marine environment. With respect to the sedimentation of trenches, the non-dimensional Trench-Keulegan-Carpenter number, KC = a/L, where a is the excursion length...

Some interactive factors affecting trench-cover integrity on low-level waste sites

International Nuclear Information System (INIS)

Hakonson, T.E.; Lane, L.J.; Steger, J.G.; DePoorter, G.L.

1982-01-01

This paper describes important mechanisms by which radionuclide can be transported from low-level waste disposal sites into biological pathways, discuss interactions of abiotic and biotic processes, and recommends environmental characteristics that should be measured to design sites that minimize this transport. Past experience at shallow land burial sites for low-level radioactive wastes suggest that occurrences of waste exposure and radionuclide transport are often related to inadequate trench cover designs. Meeting performance standards at low-level waste sites can only be achieved by recognizing that physical, chemical, and biological processes operating on and in a trench cover profile are highly interactive. Failure to do so can lead to improper design criteria and subsequent remedial action procedures that can adversely affect site stability. Based upon field experiments and computer modeling, recommendations are made on site characteristics that require measurement in order to design systems that reduce surface runoff and erosion, manage soil moisture and biota in the cover profile to maximize evapotranspiration and minimize percolation, and place bounds on the intrusion potential of plants and animals into the waste material. Major unresolved problems include developing probabilistic approaches that include climatic variability, improved knowledge of soil-water-plant-erosion relationships, development of practical vegetation establishment and maintenance procedures, prediction and quantification of site potential and plant succession, and understanding the interaction of processes occurring on and in the cover profile with deeper subsurface processes

Seepage through a hazardous-waste trench cover

Science.gov (United States)

Healy, R.W.

1989-01-01

Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216 mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest rates occurred along the edge of the cover, where seepage was highly episodic, with 84% of the total there being traced to wetting fronts from 28 individual storms. Limitations of the zero-flux-plane method were severe enough for the method to be judged inappropriate for use in this study.Water movement through a waste-trench cover under natural conditions at a low-level radioactive waste disposal site in northwestern Illinois was studied from July 1982 to June 1984, using tensiometers, a moisture probe, and meteorological instruments. Four methods were used to estimate seepage: the Darcy, zero-flux plane, surface-based water-budget, and groundwater-based water-budget methods. Annual seepage estimates ranged from 48 to 216mm (5-23% of total precipitation), with most seepage occurring in spring. The Darcy method, although limited in accuracy by uncertainty in hydraulic conductivity, was capable of discretizing seepage in space and time and indicated that seepage varied by almost an order of magnitude across the width of the trench. Lowest seepage rates occurred near the center of the cover, where seepage was gradual. Highest

Residual thermal desorption studies of Ga adatoms on trenched Si(5 5 12) surface

International Nuclear Information System (INIS)

Kumar, Praveen; Kumar, Mahesh; Shivaprasad, S.M.

2013-01-01

We present here the thermal stability studies of the room temperature adsorbed Ga/Si(5 5 12) interfaces in the monolayer coverage regime, using AES and LEED as in-situ UHV characterization probes. Ga grows in Stranski–Krastanov growth mode at RT on the 2 × 1 reconstructed Si(5 5 12) surface where islands form on top of 2 ML of flat pseudomorphic Ga, yielding a (1 × 1) LEED pattern for coverages of 1.2 ML and above. When this RT adsorbed Ga/Si(5 5 12) interface is annealed at different temperatures, initially the strained Ga adlayers relax by agglomerating into 3D islands on top of a single Ga monolayer with an activation energy of 0.19 eV in the temperature range of 200–300 °C. The remnant Ga monolayer with a sharp (1 × 1) LEED pattern desorbs at temperature >400 °C, yielding the (1 1 2)–6 × 1 and 2 × (3 3 7) sub-monolayer superstructural. Finally at 720 °C Ga completely desorbs from the surface and leaves the clean 2 × 1 reconstructed Si(5 5 12) surface. The studies demonstrate the richness of the atomically trenched high index Si(5 5 12) surface, in obtaining several anisotropic features that can be used as templates to grow self-assembled nanostructures.

Residual thermal desorption studies of Ga adatoms on trenched Si(5 5 12) surface

Energy Technology Data Exchange (ETDEWEB)

Kumar, Praveen [Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India); ISOM, Universidad Politecnia de Madrid, 28040 (Spain); Kumar, Mahesh [Physics and Energy Harvesting Group, National Physical Laboratory, New Delhi 110012 (India); Shivaprasad, S.M., E-mail: smsprasad@jncasr.ac.in [Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India)

2013-10-01

We present here the thermal stability studies of the room temperature adsorbed Ga/Si(5 5 12) interfaces in the monolayer coverage regime, using AES and LEED as in-situ UHV characterization probes. Ga grows in Stranski–Krastanov growth mode at RT on the 2 × 1 reconstructed Si(5 5 12) surface where islands form on top of 2 ML of flat pseudomorphic Ga, yielding a (1 × 1) LEED pattern for coverages of 1.2 ML and above. When this RT adsorbed Ga/Si(5 5 12) interface is annealed at different temperatures, initially the strained Ga adlayers relax by agglomerating into 3D islands on top of a single Ga monolayer with an activation energy of 0.19 eV in the temperature range of 200–300 °C. The remnant Ga monolayer with a sharp (1 × 1) LEED pattern desorbs at temperature >400 °C, yielding the (1 1 2)–6 × 1 and 2 × (3 3 7) sub-monolayer superstructural. Finally at 720 °C Ga completely desorbs from the surface and leaves the clean 2 × 1 reconstructed Si(5 5 12) surface. The studies demonstrate the richness of the atomically trenched high index Si(5 5 12) surface, in obtaining several anisotropic features that can be used as templates to grow self-assembled nanostructures.

Chemical Characteristics of Seawater and Sediment in the Yap Trench

Science.gov (United States)

Ding, H.; Sun, C.; Yang, G.

2017-12-01

In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of

Trench sampling report Salmon Site Lamar County, Mississippi

Energy Technology Data Exchange (ETDEWEB)

1994-07-01

This report describes trench excavation and sample-collection activities conducted by IT Corporation (IT) as part of the ongoing Remedial Investigation and Feasibility Study at the Salmon Site, Lamar County, Mississippi (DOE, 1992). During construction, operation, and closure of the site wastes of unknown composition were buried in pits on site. Surface-geophysical field investigations were conducted intermittently between November 1992 and October 1993 to identify potential waste-burial sites and buried metallic materials. The geophysical investigations included vertical magnetic gradient, electromagnetic conductivity, electromagnetic in-phase component, and ground-penetrating radar surveys. A number of anomalies identified by the magnetic gradiometer survey in the Reynolds Electrical & Engineering Co., Inc., (REECo) pits area indicated buried metallic objects. All of the anomalies were field checked to determine if any were caused by surface features or debris. After field checking, 17 anomalies were still unexplained; trenching was planned to attempt to identify their sources. Between December 8, 1993, and December 17, 1993, 15 trenches were excavated and soil samples were collected at the anomalies. Samples were collected, placed in 250- and 500-milliliter (m{ell}) amber glass containers, and shipped on ice to IT Analytical Services (ITAS) in St. Louis, Missouri, using standard IT chain-of-custody procedures. The samples were analyzed for various chemical and radiological parameters. Data validation has not been conducted on any of the samples. During excavation and sampling, soil samples were also collected by IT for the MSDEQ and the Mississippi Department of Radiological Health, in accordance with their instructions, and delivered into their custody.

Trench sampling report Salmon Site Lamar County, Mississippi

International Nuclear Information System (INIS)

1994-07-01

This report describes trench excavation and sample-collection activities conducted by IT Corporation (IT) as part of the ongoing Remedial Investigation and Feasibility Study at the Salmon Site, Lamar County, Mississippi (DOE, 1992). During construction, operation, and closure of the site wastes of unknown composition were buried in pits on site. Surface-geophysical field investigations were conducted intermittently between November 1992 and October 1993 to identify potential waste-burial sites and buried metallic materials. The geophysical investigations included vertical magnetic gradient, electromagnetic conductivity, electromagnetic in-phase component, and ground-penetrating radar surveys. A number of anomalies identified by the magnetic gradiometer survey in the Reynolds Electrical ampersand Engineering Co., Inc., (REECo) pits area indicated buried metallic objects. All of the anomalies were field checked to determine if any were caused by surface features or debris. After field checking, 17 anomalies were still unexplained; trenching was planned to attempt to identify their sources. Between December 8, 1993, and December 17, 1993, 15 trenches were excavated and soil samples were collected at the anomalies. Samples were collected, placed in 250- and 500-milliliter (m ell) amber glass containers, and shipped on ice to IT Analytical Services (ITAS) in St. Louis, Missouri, using standard IT chain-of-custody procedures. The samples were analyzed for various chemical and radiological parameters. Data validation has not been conducted on any of the samples. During excavation and sampling, soil samples were also collected by IT for the MSDEQ and the Mississippi Department of Radiological Health, in accordance with their instructions, and delivered into their custody

High-directionality fiber-chip grating coupler with interleaved trenches and subwavelength index-matching structure.

Science.gov (United States)

Benedikovic, Daniel; Alonso-Ramos, Carlos; Cheben, Pavel; Schmid, Jens H; Wang, Shurui; Xu, Dan-Xia; Lapointe, Jean; Janz, Siegfried; Halir, Robert; Ortega-Moñux, Alejandro; Wangüemert-Pérez, J Gonzalo; Molina-Fernández, Iñigo; Fédéli, Jean-Marc; Vivien, Laurent; Dado, Milan

2015-09-15

We present the first experimental demonstration of a new fiber-chip grating coupler concept that exploits the blazing effect by interleaving the standard full (220 nm) and shallow etch (70 nm) trenches in a 220 nm thick silicon layer. The high directionality is obtained by controlling the separation between the deep and shallow trenches to achieve constructive interference in the upward direction and destructive interference toward the silicon substrate. Utilizing this concept, the grating directionality can be maximized independent of the bottom oxide thickness. The coupler also includes a subwavelength-engineered index-matching region, designed to reduce the reflectivity at the interface between the injection waveguide and the grating. We report a measured fiber-chip coupling efficiency of -1.3  dB, the highest coupling efficiency achieved to date for a surface grating coupler in a 220 nm silicon-on-insulator platform fabricated in a conventional dual-etch process without high-index overlays or bottom mirrors.

Release mechanisms from shallow engineered trenches used as repositories for radioactive wastes

International Nuclear Information System (INIS)

Locke, J.; Wood, E.

1987-05-01

This report has been written for the Department of the Environment as part of their radioactive waste management research programme. The aim has been to identify release mechanisms of radioactivity from fully engineered trenches of the LAND 2 type and, to identify the data needed for their assessment. No direct experimental work has been involved. The report starts with a brief background to UK strategy and outlines a basic disposal system. It gives reviews of existing experience of low level radioactive waste disposal from LAND 1 trenches and of UK experience of toxic waste disposal to provide a practical basis for the next section which covers the implications of identified release mechanisms on the design requirements for an engineered trench. From these design requirements and their interaction with potential site conditions (both saturated and unsaturated zone sites are considered) an assessment of radionuclide release mechanism is made. (author)

ALARA review for the decontamination and decommissioning of the 233-S pipe trench

International Nuclear Information System (INIS)

Kornish, M.J.

1998-01-01

The 233-S Facility was completed in 1955 to expand plutonium production by further concentrating the plutonium nitrate product solution from the Reduction Oxidation (REDOX) Plant. The facility is radiologically contaminated because of operations and accidents. Isolation from REDOX and removal of the product transfer lines from the pipe trench is the second step in the decontamination and decommissioning of the entire 233-S Facility. The work scope is to isolate all piping from REDOX and then to remove all the piping/equipment from the pipe trench. The building is presently a Hazard Category 2 Nuclear Facility. A formal as low as reasonably achievable (ALARA) review is required by BHI-SH-02, Vol. 1, Procedure No. 1.22, Planning Radiological Work, when radiological conditions exceed trigger levels. The level of contamination inside the pipe trench and the process fluid piping is unknown. The potential exists to exceed the level of loose surface contamination, which requires a formal ALARA review when opening the pipe trench and cutting of piping commences. This ALARA review is for task instruction 1997-03-18-009 Revision 1, 233-S Pipe Trench Decon and Pipe Removal

Note: long range and accurate measurement of deep trench microstructures by a specialized scanning tunneling microscope.

Science.gov (United States)

Ju, Bing-Feng; Chen, Yuan-Liu; Zhang, Wei; Zhu, Wule; Jin, Chao; Fang, F Z

2012-05-01

A compact but practical scanning tunneling microscope (STM) with high aspect ratio and high depth capability has been specially developed. Long range scanning mechanism with tilt-adjustment stage is adopted for the purpose of adjusting the probe-sample relative angle to compensate the non-parallel effects. A periodical trench microstructure with a pitch of 10 μm has been successfully imaged with a long scanning range up to 2.0 mm. More innovatively, a deep trench with depth and step height of 23.0 μm has also been successfully measured, and slope angle of the sidewall can approximately achieve 67°. The probe can continuously climb the high step and exploring the trench bottom without tip crashing. The new STM could perform long range measurement for the deep trench and high step surfaces without image distortion. It enables accurate measurement and quality control of periodical trench microstructures.

Recent sediment dynamics in hadal trenches: Evidence for the influence of higher-frequency (tidal, near-inertial) fluid dynamics

Science.gov (United States)

Turnewitsch, Robert; Falahat, Saeed; Stehlikova, Jirina; Oguri, Kazumasa; Glud, Ronnie N.; Middelboe, Mathias; Kitazato, Hiroshi; Wenzhöfer, Frank; Ando, Kojiro; Fujio, Shinzou; Yanagimoto, Daigo

2014-08-01

In addition to high hydrostatic pressure, scarcity of food is viewed as a factor that limits the abundance and activity of heterotrophic organisms at great ocean depths, including hadal trenches. Supply of nutritious food largely relies on the flux of organic-rich particulate matter from the surface ocean. It has been speculated that the shape of hadal trenches helps to ‘funnel' particulate matter into the deeper parts of the trench, leading to sediment ‘focussing' and improved benthic food supply. Here we investigate for five Northwest Pacific trenches the efficiency of sediment focussing by evaluating ratios of measured (sediment-derived) and expected (water-column-derived) sedimentary inventories of the naturally occurring and radioactive particulate-matter tracer 210Pbxs. The sites comprise a broad range of surface-ocean productivity and physical-oceanographic regimes. Across the five trench-axis settings the inventory ratio varies between 0.5 and 4.1, with four trench-axis settings having ratios>1 (sediment focussing) and one trench-axis setting a ratiowinnowing). Although the fluid- and sediment-dynamical forcing behind sediment focussing remains unclear, this study finds evidence for another mechanism that is superimposed on, and counteracts, the focussing mechanism. This superimposed mechanism is related to higher-frequency (tidal, near-inertial) fluid dynamics. In particular, there is evidence for a strong and negative relation between the intensity of propagating internal tides and the extent of sediment focussing in the trench-axis. The relation can be approximated by a power function and the most intense drop in sediment focussing already occurs at moderate internal-tide intensities. This suggests that propagating internal tides may have a subtle but significant influence on particulate-matter dynamics and food supply in hadal trenches in particular, but possibly also in the deep seas in general. A mechanism for the influence of internal tides on

Process hazards review of the 904-A trench

International Nuclear Information System (INIS)

Snyder, D.E.

1988-01-01

The 904-A trench is an enclosed underground concrete containment for high level and low level radioactive waste lines between the main Laboratory Building 773-A and waste storage and shipping Building 776-A. The waste generated in laboratories and other facilities in 773-A flows by gravity into the high level and low level drain lines, which proceed from 773-A through the 904-A trench. The trench ends at 776-2A, where the underground was handling tanks for both high level and low level liquids are located. The trench serves to contain any leaks originating in the drain lines. The trench is sloped downward toward the Building 776-2A pipe gallery. Any liquid collected from the sump can be pumped automatically to a waste tank sampled. The review of the 904-A trench system included a study of the trench and piping itself, as well as a study of the high level and low level drain lines from the laboratories to the trench. The present review emphasized on examination of the hazards involved in chemical reactions in the drain lines, misuse of the drains, and criticality. The following items were examined: Process Hazards Review of the Liquid Waste Collection System, Nuclear Criticality Review of the High Level Drain System, Improvements in the 904-A Trench System, Operating Procedures, and Unusual Incidents

A Numerically and Experimentally Investigated Structure of the Turbulent Flow Past a Trench with a Separation

Directory of Open Access Journals (Sweden)

V. N. Afanasiev

2017-01-01

Full Text Available The paper studies the convective heat exchange intensification due to two-dimensional depressions formed on the initially flat surface. This problem is of interest for engineering applications because many different convective surfaces have cavities and depressions of constructive or random occurrence. During flow around a depression the boundary layer separation and its reattachment result in occurring specific phenomena, which have a significant impact on drag and heat exchange.The work involved an experimental study of hydrodynamic and heat characteristics of the turbulent boundary layer formed when there was an external airflow of the flat surface with a single transversal separation trench.The experimental part used an open subsonic low-turbulence wind tunnel operating in suction mode. A numerical simulation involves hydrodynamics and heat exchange parameters analysis via solution of the system of differential equations, which describe momentum and heat transport processes using ANSYS Fluent solver.The experimental data of this study are compared with numerical simulation results obtained by solving the steady Reynolds-averaged Navier-Stokes equations (RANS with a two-parametrical Menter k-ω (MSST turbulence model.The comparison shows that simulation results are in good agreement with experimental data, heat exchange surface profiling by a transversal trench system with or without flow separation does not lead to increasing surface drag and, moreover, at the certain ratios of geometrical parameters (cylindrical trenches with h/S£ 0.5 it can decrease the surface drag. Surface conjugations in these depressions should be smooth without any sharp curves and transitions, which can lead to forming stagnation regions.The reason for raising heat exchange is a spatial non-uniformity of the generated turbulence field. During flow analysis there were two sources of turbulence generation found out, namely a wall (heat exchange surface and a mixing

Challenges in hardening technologies using shallow-trench isolation

International Nuclear Information System (INIS)

Shaneyfelt, M.R.; Dodd, P.E.; Draper, B.L.; Flores, R.S.

1998-02-01

Challenges related to radiation hardening CMOS technologies with shallow-trench isolation are explored. Results show that trench hardening can be more difficult than simply replacing the trench isolation oxide with a hardened field oxide

Revised ground-water monitoring compliance plan for the 300 area process trenches

Energy Technology Data Exchange (ETDEWEB)

Schalla, R.; Aaberg, R.L.; Bates, D.J.; Carlile, J.V.M.; Freshley, M.D.; Liikala, T.L.; Mitchell, P.J.; Olsen, K.B.; Rieger, J.T.

1988-09-01

This document contains ground-water monitoring plans for process-water disposal trenches located on the Hanford Site. These trenches, designated the 300 Area Process Trenches, have been used since 1973 for disposal of water that contains small quantities of both chemicals and radionuclides. The ground-water monitoring plans contained herein represent revision and expansion of an effort initiated in June 1985. At that time, a facility-specific monitoring program was implemented at the 300 Area Process Trenches as part of a regulatory compliance effort for hazardous chemicals being conducted on the Hanford Site. This monitoring program was based on the ground-water monitoring requirements for interim-status facilities, which are those facilities that do not yet have final permits, but are authorized to continue interim operations while engaged in the permitting process. The applicable monitoring requirements are described in the Resource Conservation and Recovery Act (RCRA), 40 CFR 265.90 of the federal regulations, and in WAC 173-303-400 of Washington State's regulations (Washington State Department of Ecology 1986). The program implemented for the process trenches was designed to be an alternate program, which is required instead of the standard detection program when a facility is known or suspected to have contaminated the ground water in the uppermost aquifer. The plans for the program, contained in a document prepared by the US Department of Energy (USDOE) in 1985, called for monthly sampling of 14 of the 37 existing monitoring wells at the 300 Area plus the installation and sampling of 2 new wells. 27 refs., 25 figs., 15 tabs.

The medical response to trench nephritis in World War One.

Science.gov (United States)

Atenstaedt, R L

2006-08-01

Around the 90-year anniversary of the Battle of the Somme, it is important to remember the international effort that went into responding to the new diseases, which appeared during the First World War, such as trench nephritis. This condition arose among soldiers in spring 1915, characterized by breathlessness, swelling of the face or legs, headache, sore throat, and the presence of albumin and renal casts in urine. It was speedily investigated by the military-medical authorities. There was debate over whether it was new condition or streptococcal nephritis, and the experts agreed that it was a new condition. The major etiologies proposed were infection, exposure, and diet (including poisons). Research pointed to the origin of the disease as being infective rather than toxic, but no definite cause was discovered. A number of labels were given to the disease, including war nephritis. However, trench nephritis was the one used most widely. Trench nephritis was a serious problem for the Allies, leading to 35 000 casualties in the British and 2000 in the American forces. There were also hundreds of deaths. The condition was treated in line with pre-war regimens designed for acute nephritis. No significant preventative methods were implemented for trench nephritis, as there was no consensus regarding causation. The medical response to trench nephritis was largely ineffective, with medical commentators recognizing that there had been a lack of medical progress.

Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva, Honduras

Energy Technology Data Exchange (ETDEWEB)

Oakley, Stewart M., E-mail: soakley@csuchico.edu [Department of Civil Engineering, Chico State University, California State University, Chico, CA 95929 (United States); Jimenez, Ramon, E-mail: rjimenez1958@yahoo.com [Public Works, Municipality of Villanueva, Cortes (Honduras)

2012-12-15

Highlights: Black-Right-Pointing-Pointer Open dumping is the most common form of waste disposal in neglected small cities. Black-Right-Pointing-Pointer Semi-mechanized landfills can be a sustainable option for small cities. Black-Right-Pointing-Pointer We present the theory of design and operation of semi-mechanized landfills. Black-Right-Pointing-Pointer Villanueva, Honduras has operated its semi-mechanized landfill for 15 years. Black-Right-Pointing-Pointer The cost of operation is US$4.60/ton with a land requirement of 0.2m{sup 2}/person-year. - Abstract: Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country's total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1-3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in

Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva, Honduras

International Nuclear Information System (INIS)

Oakley, Stewart M.; Jimenez, Ramón

2012-01-01

Highlights: ► Open dumping is the most common form of waste disposal in neglected small cities. ► Semi-mechanized landfills can be a sustainable option for small cities. ► We present the theory of design and operation of semi-mechanized landfills. ► Villanueva, Honduras has operated its semi-mechanized landfill for 15 years. ► The cost of operation is US$4.60/ton with a land requirement of 0.2m 2 /person-year. - Abstract: Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country’s total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1–3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in Villanueva has operated for 15 years, using a total land area of approximately 11 ha for a population that grew from 23,000 to 48

Modeling the flow of water in and around shallow burial trenches

International Nuclear Information System (INIS)

Suen, C.J.

1988-01-01

Water flow through a generic low-level waste burial trench has been modeled for a vertical cross-section perpendicular to the longitudinal axis of an elongated trenched, using the finite element code, FEMWATER, in two-dimensional vertical mode. The grid consists of 513 nodes and 468 variable-size quadrilateral elements, and the simulation domain is about 56 m (H) /times/ 34 m (V). The traench, which is situated in the unsaturated zone, measures approximately 28 m wide and 10 m deep in cross-section, and is composed of three types of soil - a high-conductivity gravel cap on top, a low-conductivity clay layer beneath it, and backfill soil in the waste burial region. The rest of the domain is made up of undisturbed soil. Different cases have been simulated by varying boundary conditions, geometry and hydraulic properties. These results are used in radionuclide transport calculations to determine the ''source term'' (4). In addition, numerical experiments provide valuable information in trench design, such as, the geometry of the moisture barrier. Results from these experiments indicates that a moderate extension (8 m) of the clay layer beyond the sides of the trench can significantly reduce the net water flow (by 42%). They also show that sparsely distributed waste package have minimal effect on the net flow through the trench. 10 refs., 7 figs., 3 tabs

Trench Safety–Using a Qualitative Approach to Understand Barriers and Develop Strategies to Improve Trenching Practices

Science.gov (United States)

FLYNN, MICHAEL A.; SAMPSON, JULIE M.

2015-01-01

Despite efforts to ensure workplace safety and health, injuries and fatalities related to trenching and excavation remain alarmingly high in the construction industry. Because properly installed trenching protective systems can potentially reduce the significant number of trenching fatalities, there is clearly a need to identify the barriers to the use of these systems and to develop strategies to ensure these systems are utilized consistently. The current study reports on the results of focus groups with construction workers and safety management personnel to better understand these barriers and to identify solutions. The results suggest several factors, from poor planning to pressures from experienced workers and supervisors, which present barriers to safe trenching practices. Based on the results, it is recommended that safety trainings incorporate unique messages for new workers, experienced workers and management in an effort to motivate each group to work safely as well as provide them with solutions to overcome the identified barriers. PMID:26550006

Effects of vegetation and soil-surface cover treatments on the hydrologic behavior of low-level waste trench caps

International Nuclear Information System (INIS)

Lopez, E.A.; Barnes, F.J.; Antonio, E.J.

1988-01-01

Preliminary results are presented on a three-year field study at Los Alamos National Laboratory to evaluate the influence of different low-level radioactive waste trench cap designs on water balance under natural precipitation. Erosion plots having two different vegetative covers (shrubs and grasses) and with either gravel-mulched or unmulched soil surface treatments have been established on three different soil profiles on a decommissioned waste site. Total runoff and soil loss from each plot is measured after each precipitation event. Soil moisture is measured biweekly while plant canopy cover is measured seasonally. Preliminary results from the first year show that the application of a gravel mulch reduced runoff by 73 to 90%. Total soil loss was reduced by 83 to 93% by the mulch treatment. On unmulched plots, grass cover reduced both runoff and soil loss by about 50% compared to the shrub plots. Continued monitoring of the study site will provide data that will be used to analyze complex interactions between independent variables such rainfall amount and intensity, antecedent soil moisture, and soil and vegetation factors, as they influence water balance, and soil erosion. 18 refs., 2 figs., 3 tabs

Trench capacitor and method for producing the same

NARCIS (Netherlands)

2009-01-01

A method of fabricating a trench capacitor, and a trench capacitor fabricated thereby, are disclosed. The method involves the use of a vacuum impregnation process for a sol-gel film, to facilitate effective deposition of high- permittivity materials within a trench in a semiconductor substrate, to

The East Garrington Trench and Gate system: it works

International Nuclear Information System (INIS)

Bowles, M.; Rimbey, S.; Bentley, L.; Thomas, D.; Hoyne, B.

1997-01-01

A 'trench and gate' system (a modification of the 'funnel and gate' system) has been installed at the Amoco-operated East Garrington gas plant in Alberta to provide long-term remediation for treating contaminated groundwater plumes hosted by low hydraulic conductivity sediments. Modification to the funnel and gate design includes an up gradient high hydraulic conductivity trench and a down gradient infiltration gallery which was found to be effective in biodegrading BTEX (benzene, toluene, ethylbenzene and xylene) compounds. A comprehensive monitoring program was set up to characterize the groundwater flow system. Several indigenous hydrocarbon degrading organisms have been identified. It was shown that locally, under aerobic conditions, phosphorus was the limiting nutrient. 13 refs., 3 tabs., 10 figs

300 Area Process Trenches Verification Package

International Nuclear Information System (INIS)

Lerch, J.A.

1998-03-01

The purpose of this verification package is to document achievement of the remedial action objectives for the 300 Area Process Trenches (300 APT) located within the 300-FF-1 Operable Unit (OU). The 300 APT became active in 1975 as a replacement for the North and South Process Pond system that is also part of the 300-FF-1 OU. The trenches received 300 Area process effluent from the uranium fuel fabrication facilities. Waste from the 300 Area laboratories that was determined to be below discharge limits based on monitoring performed at the 307 retention basin was also released to the trenches. Effluent flowed through the headworks sluice gates, down a concrete apron, and into the trenches. From the beginning of operations in 1975 until 1993, a continuous, composite sampler was located at the headwork structure to analyze process effluent at the point of discharge to the environment

Ultra-low specific on-resistance SOI double-gate trench-type MOSFET

International Nuclear Information System (INIS)

Lei Tianfei; Luo Xiaorong; Ge Rui; Chen Xi; Wang Yuangang; Yao Guoliang; Jiang Yongheng; Zhang Bo; Li Zhaoji

2011-01-01

An ultra-low specific on-resistance (R on,sp ) silicon-on-insulator (SOI) double-gate trench-type MOSFET (DG trench MOSFET) is proposed. The MOSFET features double gates and an oxide trench: the oxide trench is in the drift region, one trench gate is inset in the oxide trench and one trench gate is extended into the buried oxide. Firstly, the double gates reduce R on,sp by forming dual conduction channels. Secondly, the oxide trench not only folds the drift region, but also modulates the electric field, thereby reducing device pitch and increasing the breakdown voltage (BV). ABV of 93 V and a R on,sp of 51.8 mΩ·mm 2 is obtained for a DG trench MOSFET with a 3 μm half-cell pitch. Compared with a single-gate SOI MOSFET (SG MOSFET) and a single-gate SOI MOSFET with an oxide trench (SG trench MOSFET), the R on,sp of the DG trench MOSFET decreases by 63.3% and 33.8% at the same BV, respectively. (semiconductor devices)

Unreviewed Disposal Question Evaluation: Waste Disposal In Engineered Trench #3

Energy Technology Data Exchange (ETDEWEB)

Hamm, L. L.; Smith, F. G. III; Flach, G. P.; Hiergesell, R. A.; Butcher, B. T.

2013-07-29

Because Engineered Trench #3 (ET#3) will be placed in the location previously designated for Slit Trench #12 (ST#12), Solid Waste Management (SWM) requested that the Savannah River National Laboratory (SRNL) determine if the ST#12 limits could be employed as surrogate disposal limits for ET#3 operations. SRNL documented in this Unreviewed Disposal Question Evaluation (UDQE) that the use of ST#12 limits as surrogates for the new ET#3 disposal unit will provide reasonable assurance that Department of Energy (DOE) 435.1 performance objectives and measures (USDOE, 1999) will be protected. Therefore new ET#3 inventory limits as determined by a Special Analysis (SA) are not required.

Increasing emitter efficiency in 3.3-kV enhanced trench IGBTs for higher short-circuit capability

DEFF Research Database (Denmark)

Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

2018-01-01

In this paper, a 3.3-kV Enhanced Trench IGBT has been designed with a high emitter efficiency, for improving its short-circuit robustness. The carrier distribution profile has been shaped in a way that it is possible to increase the electric field at the surface of the IGBT, and thereby, counteract...... the Kirk Effect onset. This design approach is beneficial for mitigating high-frequency oscillations, typically observed in IGBTs under short-circuit conditions. The effectiveness of the proposed design rule is validated by means of mixed-mode device simulations. Then, two IGBTs have been fabricated...... with different emitter efficiencies and tested under short circuit, validating that the high-frequency oscillations can be mitigated, with higher emitter efficiency IGBT designs....

Electrochemical trench etching of silicon triggered via mechanical nanocontacts

Energy Technology Data Exchange (ETDEWEB)

Gassilloud, R.; Michler, J. [EMPA, Materials Science and Technology, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Schmuki, P. [Department of Materials Science, LKO, University of Erlangen-Nuernberg, Martensstrasse 7, D-91058 Erlangen (Germany)

2007-12-01

We report a method to produce microstructures on silicon wafers using a microscratching technique followed by a subsequent electrochemical trench etching in hydrofluoric-based electrolyte. Micro-scratches are used to trigger macropore formation. We show that mask-less dissolved trenches with aspect ratios up to 1:7 are formed at the scratched regions on (0 0 1)Si surface. The micro-scratches orientate the macropores formation by aligning them in the scratching direction. We propose that dislocations formed during scratching are firstly dissolved leading to the formation of V-shape grooves. The V-shape geometries obtained by this way are used to initiate the macropores nucleation; i.e. due to the geometry, an avalanche current occurs at the grooves base and thus induces local dissolutions of the substrate. High rate local dissolutions are achieved by back-side illumination of the Si wafer. (author)

Test Area for Remedial Actions (TARA) site characterization and dynamic compaction of low-level radioactive waste trenches. FY 1988 progress report

Energy Technology Data Exchange (ETDEWEB)

Davis, E. C.; Spalding, B. P.; Lee, S. Y.; Hyder, L. K.

1989-01-01

As part of a low-level radioactive waste burial ground stabilization and closure technology demonstration project, a group of five burial trenches in Oak Ridge National Laboratory (ORNL) Solid Waste Storage Area (SWSA) 6 was selected as a demonstration site for testing trench compaction, trench grouting, and trench cap installation and performance. This report focuses on site characterization, trench compaction, and grout-trench leachate compatibility. Trench grouting and cap design and construction will be the subject of future reports. The five trenches, known as the Test Area for Remedial Actions (TARA) site, are contained within a hydrologically isolated area of SWSA 6; for that reason, any effects of stabilization activities on site performance and groundwater quality will be separable from the influence of other waste disposal units in SWSA 6. To obviate the chronic problem of burial trench subsidence and to provide support for an infiltration barrier cap, these five trenches were dynamically compacted by repeated dropping of a 4-ton weight onto each trench from heights of approximately 7 m.

Mantle Serpentinization near the Central Mariana Trench Constrained by Ocean Bottom Surface Wave Observations

Science.gov (United States)

Cai, C.; Wiens, D. A.; Lizarralde, D.; Eimer, M. O.; Shen, W.

2017-12-01

We investigate the crustal and uppermost mantle seismic structure across the Mariana trench by jointly inverting Rayleigh wave phase and group velocities from ambient noise and longer period phase velocities from Helmholtz tomography of teleseismic waveforms. We use data from a temporary deployment in 2012-2013, consisting of 7 island-based stations and 20 broadband ocean bottom seismographs, as well as data from the USGS Northern Mariana Islands Seismograph Network. To avoid any potential bias from the starting model, we use a Bayesian Monte-Carlo algorithm to invert for the azimuthally-averaged SV-wave velocity at each node. This method also allows us to apply prior constraints on crustal thickness and other parameters in a systematic way, and to derive formal estimates of velocity uncertainty. The results show the development of a low velocity zone within the incoming plate beginning about 80 km seaward of the trench axis, consistent with the onset of bending faults from bathymetry and earthquake locations. The maximum depth of the velocity anomaly increases towards the trench, and extends to about 30 km below the seafloor. The low velocities persist after the plate is subducted, as a 20-30 km thick low velocity layer with a somewhat smaller velocity reduction is imaged along the top of the slab beneath the forearc. An extremely low velocity zone is observed beneath the serpentine seamounts in the outer forearc, consistent with 40% serpentinization in the forearc mantle wedge. Azimuthal anisotropy results show trench parallel fast axis within the incoming plate at uppermost mantle depth (2%-4% anisotropy). All these observations suggest the velocity reduction in the incoming plate prior to subduction results from both serpentinized normal faults and water-filled cracks. Water is expelled from the cracks early in subduction, causing a modest increase in the velocity of the subducting mantle, and moves upward and causes serpentinization of the outer forearc

Investigation on proper materials of a liner system for trench type disposal facilities of radioactive wastes from research, industrial and medical facilities

International Nuclear Information System (INIS)

Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Arikawa, Masanobu; Sakamoto, Yoshiaki

2011-08-01

The Low-level Radioactive Waste Disposal Project Center of Japan Atomic Energy Agency will settle on near surface disposal facilities with and without engineered barriers for radioactive wastes from research, industrial and medical facilities. Both of them are so called 'concrete pit type' and 'trench type', respectively. The technical standard of constructing and operating a disposal facility based on 'Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors' have been regulated partly by referring to that of 'Waste Management and Public Cleansing Law'. This means that the concrete pit type and the trench type disposal facility resemble an isolated type for specified industrial wastes and a non leachate controlled type final disposal site for stable industrial wastes, respectively. On the other, We plan to design a disposal facility with a liner system corresponding to a leachate controlled type final disposal site on a crucial assumption that radioactive wastes other than stable industrial wastes to be disposed into the trench type disposal facility is generated. By current nuclear related regulations in Japan, There are no technical standard of constructing the disposal facility with the liner system referring to that of 'Waste Management and Public Cleansing Law'. We investigate the function of the liner system in order to design a proper liner system for the trench type disposal facility. In this report, We investigated liner materials currently in use by actual leachate controlled type final disposal sites in Japan. Thereby important items such as tensile strength, durability from a view point of selecting proper liner materials were studied. The items were classified into three categories according to importance. We ranked proper liner materials for the trench type disposal facility by evaluating the important items per material. As a result, high density polyethylene(HDPE) of high elasticity type polymetric sheet was selected

Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

International Nuclear Information System (INIS)

Blanco, A.; Pujadas, R.; Fernández, C.; Cavalaro, S.H.P.; Aguado, A.

2017-01-01

Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience. [es

Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete

Directory of Open Access Journals (Sweden)

A. Blanco

2017-09-01

Full Text Available Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench’s structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.

Trial coring in LLRW trenches at Chalk River

International Nuclear Information System (INIS)

Donders, R.E.; Killey, R.W.D.; Franklin, K.J.; Strobel, G.S.

1996-11-01

As part of a program to better characterize the low-hazard radioactive waste managed by AECL at Chalk River Laboratories, coring techniques in waste trenches are being assessed. Trial coring has demonstrated that sampling in waste regions is possible, and that boreholes can be placed through the waste trenches. Such coring provides a valuable information-gathering technique. Information available from trench coring includes: trench cover depth, waste region depth, waste compaction level, and detailed stratigraphic data; soil moisture content and facility drainage performance; borehole gamma logs that indicate radiation levels in the region of the borehole; biochemical conditions in the waste regions, vadose zone, and groundwater; site specific information relevant to contaminant migration modelling or remedial actions; information on contaminant releases and inventories. Boreholes through the trenches can also provide a means for early detection of potential contaminant releases. (author). 4 refs., 4 tabs., 4 figs

Unreviewed Disposal Question Evaluation: Waste Disposal in Engineered Trenches 3 and 4

Energy Technology Data Exchange (ETDEWEB)

Butcher, T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hamm, L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Flach, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-12-12

Revision 0 of this UDQE addressed the proposal to place Engineered Trench #3 (ET#3) in the footprint designated for Slit Trench #12 (ST#12) and operate using ST#12 disposal limits. Similarly, Revision 1 evaluates whether ET#4 can be located in and operated to Slit Trench #13 (ST#13) disposal limits. Both evaluations conclude that the proposed operations result in an acceptably small risk of exceeding a SOF of 1.0 and approve these actions from a performance assessment (PA) perspective. Because ET#3 will be placed in the location previously designated for ST#12, Solid Waste Management (SWM) requested that the Savannah River National Laboratory (SRNL) determine if the ST#12 limits could be employed as surrogate disposal limits for ET#3 operations. SRNL documented in this Unreviewed Disposal Question Evaluation (UDQE) that the use of ST#12 limits as surrogates for the new ET#3 disposal unit will provide reasonable assurance that Department of Energy (DOE) 435.1 performance objectives and measures (USDOE, 1999) will be protected. Therefore, new ET#3 inventory limits as determined by a Special Analysis (SA) are not required.

Flux based modeling and simulation of dry etching for fabrication of silicon deep trench structures

Energy Technology Data Exchange (ETDEWEB)

Malik Rizwan [State Key Laboratory of Digital Manufacturing Equipment and technology, Huazhong University of Science and Technology, 1037 Luoyu road, Wuhan, China 43007 (China); Shi Tielin; Tang Zirong; Liu Shiyuan, E-mail: zirong@mail.hust.edu.cn, E-mail: rizwanmalik@smail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, 1037 Luoyu road Wuhan, 430074 (China)

2011-02-01

Deep reactive ion etching (DRIE) process is a key growth for fabrication of micro-electromechanical system (MEMS) devices. Due to complexity of this process, including interaction of the process steps, full analytical modeling is complex. Plasma process holds deficiency of understanding because it is very easy to measure the results empirically. However, as device parameters shrink, this issue is more critical. In this paper, our process was modeled qualitatively based on 'High Density Plasma Etch Model'. Deep trench solutions of etch rate based on continuity equation were successfully generated first time through mathematical analysis. It was also proved that the product of fluorine and gas phase concentration in SF{sub 6} remains identical during both deposition and etching stages. The etching process was treated as a combination of isotropic, directional and angle-dependent component parts. It exploited a synergistic balance of chemical as well as physical etching for promoting silicon trenches and high aspect ratio structures. Simulations were performed for comprehensive analysis of fluxes coming towards the surface during chemical reaction of gas. It is observed that near the surface, the distribution of the arrival flux follows a cosine distribution. Our model is feasible to analyze various parameters like gas delivery, reactor volume and temperature that help to assert large scale effects and to optimize equipment design.

Neglecting safety precautions may lead to trenching fatalities.

Science.gov (United States)

Deatherage, J Harold; Furches, Lisa K; Radcliffe, Mike; Schriver, William R; Wagner, John P

2004-06-01

Trench collapses ranked as the seventh leading cause of the possible twenty-nine causes of OSHA-inspected fatal construction events during the period 1991-2001. This study aims to examine why these fatalities occurred. Forty-four case files from OSHA inspections of fatal trench collapses were reviewed. Improper protection of the excavation site where work was taking place was the leading fatality cause. Several organizational or physical conditions were present at many fatal sites; the most frequent was that no training had been provided for trenching. Presence of a competent, diligent person at the site would have prohibited most fatalities. The top cited violation was lack of protection, that is, benching, shoring, sloping, trench boxes, etc. (29 CFR 1926.652 (a) (1)). Copyright 2004 Wiley-Liss, Inc.

Influence of geometrical and electrical parameters of masking layers on the electrochemical etching of silicon for single trench formation

International Nuclear Information System (INIS)

Gautier, G; Ventura, L; Jerisian, R

2005-01-01

Deep single trenches can be produced at the edge of apertures of protective films masking the surface of silicon samples. This macropore formation, from polarized HF based solutions, is electrically activated depending on the mask geometrical and physical parameters whatever the silicon type or the electrolyte composition. The mask thickness increase is known to induce deeper trenches. In this paper, we show that we can predict and localize this phenomenon by simulating two dimensional hole current distributions below the mask. We demonstrate also the influence of the material permittivity on trench depth. These 2D simulation results are correlated with experimental results

Elimination of trench defects and V-pits from InGaN/GaN structures

International Nuclear Information System (INIS)

Smalc-Koziorowska, Julita; Grzanka, Ewa; Czernecki, Robert; Schiavon, Dario; Leszczyński, Mike

2015-01-01

The microstructural evolution of InGaN/GaN multiple quantum wells grown by metalorganic chemical vapor phase epitaxy was studied as a function of the growth temperature of the GaN quantum barriers (QBs). We observed the formation of basal stacking faults (BSFs) in GaN QBs grown at low temperature. The presence of BSFs terminated by stacking mismatch boundaries (SMBs) leads to the opening of the structure at the surface into a V-shaped trench loop. This trench may form above an SMB, thereby terminating the BSF, or above a junction between the SMB and a subsequent BSF. Fewer BSFs and thus fewer trench defects were observed in GaN QBs grown at temperatures higher than 830 °C. Further increase in the growth temperature of the GaN QBs led to the suppression of the threading dislocation opening into V-pits

Vertically distinct microbial communities in the Mariana and Kermadec trenches

Science.gov (United States)

Donaldson, Sierra; Osuntokun, Oladayo; Xia, Qing; Nelson, Alex; Blanton, Jessica; Allen, Eric E.; Church, Matthew J.; Bartlett, Douglas H.

2018-01-01

Hadal trenches, oceanic locations deeper than 6,000 m, are thought to have distinct microbial communities compared to those at shallower depths due to high hydrostatic pressures, topographical funneling of organic matter, and biogeographical isolation. Here we evaluate the hypothesis that hadal trenches contain unique microbial biodiversity through analyses of the communities present in the bottom waters of the Kermadec and Mariana trenches. Estimates of microbial protein production indicate active populations under in situ hydrostatic pressures and increasing adaptation to pressure with depth. Depth, trench of collection, and size fraction are important drivers of microbial community structure. Many putative hadal bathytypes, such as members related to the Marinimicrobia, Rhodobacteraceae, Rhodospirilliceae, and Aquibacter, are similar to members identified in other trenches. Most of the differences between the two trench microbiomes consists of taxa belonging to the Gammaproteobacteria whose distributions extend throughout the water column. Growth and survival estimates of representative isolates of these taxa under deep-sea conditions suggest that some members may descend from shallower depths and exist as a potentially inactive fraction of the hadal zone. We conclude that the distinct pelagic communities residing in these two trenches, and perhaps by extension other trenches, reflect both cosmopolitan hadal bathytypes and ubiquitous genera found throughout the water column. PMID:29621268

Nematode communities in sediments of the Kermadec Trench, Southwest Pacific Ocean

Science.gov (United States)

Leduc, Daniel; Rowden, Ashley A.

2018-04-01

Hadal trenches are characterized by environmental conditions not found in any other deep-sea environment, such as steep topography and periodic disturbance by turbidity flows, which are likely responsible for the distinct nature of benthic communities of hadal trenches relative to those of the abyssal plain. Nematodes are the most abundant metazoans in the deep-sea benthos, but it is not yet clear if different trenches host distinct nematode communities, and no data are yet available on the communities of most trenches, including the Kermadec Trench in the Southwest Pacific. Quantitative core samples from the seafloor of the Kermadec Trench were recently obtained from four sites at 6000-9000 m depth which allowed for analyses of meiofauna, and nematodes in particular, for the first time. Nematode community and trophic structure was also compared with other trenches using published data. There was a bathymetric gradient in meiofauna abundance, biomass, and community structure within the Kermadec Trench, but patterns for species richness were ambiguous depending on which metric was used. There was a change in community structure from shallow to deep sites, as well as a consistent change in community structure from the upper sediment layers to the deeper sediment layers across the four sites. These patterns are most likely explained by variation in food availability within the trench, and related to trench topography. Together, deposit and microbial feeders represented 48-92% of total nematode abundance in the samples, which suggests that fine organic detritus and bacteria are major food sources. The relatively high abundance of epigrowth feeders at the 6000 and 9000 m sites (38% and 31%, respectively) indicates that relatively freshly settled microalgal cells represent another important food source at these sites. We found a significant difference in species community structure between the Kermadec and Tonga trenches, which was due to both the presence/absence of

Habitat heterogeneity of hadal trenches: Considerations and implications for future studies

Science.gov (United States)

Stewart, Heather A.; Jamieson, Alan J.

2018-02-01

The hadal zone largely comprises a series of subduction trenches that do not form part of the continental shelf-slope rise to abyssal plain continuum. Instead they form geographically isolated clusters of deep-sea (6000-11,000 m water depth) environments. There is a growing realization in hadal science that ecological patterns and processes are not driven solely by responses to hydrostatic pressure, with comparable levels of habitat heterogeneity as observed in other marine biozones. Furthermore, this heterogeneity can be expressed at multiple scales from inter-trench levels (degrees of geographical isolation, and biochemical province), to intra-trench levels (variation between trench flanks and axis), topographical features within the trench interior (sedimentary basins, ridges, escarpments, 'deeps', seamounts) to the substrate of the trench floor (seabed-sediment composition, mass movement deposits, bedrock outcrop). Using best available bathymetry data combined with the largest lander-derived imaging dataset that spans the full depth range of three hadal trenches (including adjacent slopes); the Mariana, Kermadec and New Hebrides trenches, the topographic variability, fine-scale habitat heterogeneity and distribution of seabed sediments of these three trenches have been assessed for the first time. As well as serving as the first descriptive study of habitat heterogeneity at hadal depths, this study also provides guidance for future hadal sampling campaigns taking into account geographic isolation, total trench particulate organic matter flux, maximum water depth and area.

GaAs on Si epitaxy by aspect ratio trapping: Analysis and reduction of defects propagating along the trench direction

Energy Technology Data Exchange (ETDEWEB)

Orzali, Tommaso, E-mail: tommaso.orzali@sematech.org; Vert, Alexey; O' Brien, Brendan; Papa Rao, Satyavolu S. [SEMATECH, 257 Fuller Rd Suite 2200, Albany, New York 12203 (United States); Herman, Joshua L.; Vivekanand, Saikumar [College of Nanoscale Science and Engineering, SUNY Polytechnic Institute, 251 Fuller Road, Albany, New York 12203 (United States); Hill, Richard J. W. [Now at Micron Technologies, 8000 S Federal Way, Boise, Idaho 83716 (United States); Karim, Zia [AIXTRON, Inc., 1139 Karlstad Dr., Sunnyvale, California 94089 (United States)

2015-09-14

The Aspect Ratio Trapping technique has been extensively evaluated for improving the quality of III-V heteroepitaxial films grown on Si, due to the potential for terminating defects at the sidewalls of SiO{sub 2} patterned trenches that enclose the growth region. However, defects propagating along the trench direction cannot be effectively confined with this technique. We studied the effect of the trench bottom geometry on the density of defects of GaAs fins, grown by metal-organic chemical vapor deposition on 300 mm Si (001) wafers inside narrow (<90 nm wide) trenches. Plan view and cross sectional Scanning Electron Microscopy and Transmission Electron Microscopy, together with High Resolution X-Ray Diffraction, were used to evaluate the crystal quality of GaAs. The prevalent defects that reach the top surface of GaAs fins are (111) twin planes propagating along the trench direction. The lowest density of twin planes, ∼8 × 10{sup 8 }cm{sup −2}, was achieved on “V” shaped bottom trenches, where GaAs nucleation occurs only on (111) Si planes, minimizing the interfacial energy and preventing the formation of antiphase boundaries.

Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration

Science.gov (United States)

Heilweil, Victor M.; Benoit, Jerome; Healy, Richard W.

2015-01-01

Spreading-basin methods have resulted in more than 130 million cubic meters of recharge to the unconfined Navajo Sandstone of southern Utah in the past decade, but infiltration rates have slowed in recent years because of reduced hydraulic gradients and clogging. Trench infiltration is a promising alternative technique for increasing recharge and minimizing evaporation. This paper uses a variably saturated flow model to further investigate the relative importance of the following variables on rates of trench infiltration to unconfined aquifers: saturated hydraulic conductivity, trench spacing and dimensions, initial water-table depth, alternate wet/dry periods, and number of parallel trenches. Modeling results showed (1) increased infiltration with higher hydraulic conductivity, deeper initial water tables, and larger spacing between parallel trenches, (2) deeper or wider trenches do not substantially increase infiltration, (3) alternating wet/dry periods result in less overall infiltration than keeping the trenches continuously full, and (4) larger numbers of parallel trenches within a fixed area increases infiltration but with a diminishing effect as trench spacing becomes tighter. An empirical equation for estimating expected trench infiltration rates as a function of hydraulic conductivity and initial water-table depth was derived and can be used for evaluating feasibility of trench infiltration in other hydrogeologic settings

New GaN Schottky barrier diode employing a trench on AlGaN/GaN heterostructure

Science.gov (United States)

Ha, Min-Woo; Lee, Seung-Chul; Choi, Young-Hwan; Kim, Soo-Seong; Yun, Chong-Man; Han, Min-Koo

2006-10-01

A new GaN Schottky barrier diode employing a trench structure, which is proposed and fabricated, successfully decreases a forward voltage drop without sacrificing any other electric characteristics. The trench is located in the middle of Schottky contact during a mesa etch. The Schottky metal of Pt/Mo/Ti/Au is e-gun evaporated on the 300 nm-deep trench as well as the surface of the proposed GaN Schottky barrier diode. The trench forms the vertical Au Schottky contact and lateral Pt Schottky contact due to the evaporation sequence of Schottky metal. The forward voltage drops of the proposed diode and conventional one are 0.73 V and 1.25 V respectively because the metal work function (5.15 eV) of the vertical Au Schottky contact is considerably less than that of the lateral Pt Schottky contact (5.65 eV). The proposed diode exhibits the low on-resistance of 1.58 mΩ cm 2 while the conventional one exhibits 8.20 mΩ cm 2 due to the decrease of a forward voltage drop.

Geology of the Integrated Disposal Facility Trench

International Nuclear Information System (INIS)

Reidel, Steve P.; Fecht, Karl R.

2005-01-01

This report describes the geology of the integrated Disposal Facility (IDF) Trench. The stratigraphy consists of some of the youngest sediments of the Missoula floods (younger than 770 ka). The lithology is dominated sands with minor silts and gravels that are largely unconsolidated. The stratigraphy can be subdivided into five geologic units that can be mapped throughout the trench. Four of the units were deposited by the Missoula floods and the youngest consists of windblown sand and silt. The sediment has little moisture and is consistent with that observed in the characterization boreholes. The sedimentary layers are flat lying and there are no faults or folds present. Two clastic dikes were encountered, one along the west wall and one that can be traced from the north to the southwall. The north-south clastic dike nearly bifurcates the trench but the west wall clastic dike can not be traced very far east into the trench. The classic dikes consist mainly of sand with clay-lined walls. The sediment in the dikes is compacted to partly cemented and are more resistant than the layered sediments

300 Area Process Trenches Closure Plan

International Nuclear Information System (INIS)

Luke, S.N.

1994-01-01

Since 1987, Westinghouse Hanford Company has been a major contractor to the US Department of Energy, Richland Operations Office and has served as co-operator of the 300 Area Process Trenches, the waste management unit addressed in this closure plan. For the purposes of the Resource Conservation and Recovery Act, Westinghouse Hanford Company is identified as ''co-operator.'' The 300 Area Process Trenches Closure Plan (Revision 0) consists of a Resource Conservation and Recovery Act Part A Dangerous Waste Permit Application, Form 3 and a Resource Conservation and Recovery Act Closure Plan. An explanation of the Part A Permit Application, Form 3 submitted with this document is provided at the beginning of the Part A Section. The closure plan consists of nine chapters and six appendices. The 300 Area Process Trenches received dangerous waste discharges from research and development laboratories in the 300 Area and from fuels fabrication processes. This waste consisted of state-only toxic (WT02), corrosive (D002), chromium (D007), spent halogenated solvents (F001, F002, and F003), and spent nonhalogented solvent (F005). Accurate records are unavailable concerning the amount of dangerous waste discharged to the trenches. The estimated annual quantity of waste (item IV.B) reflects the total quantity of both regulated and nonregulated waste water that was discharged to the unit

In situ grouting of low-level burial trenches with a cement-based grout

International Nuclear Information System (INIS)

Francis, C.W.; Spalding, B.P.

1991-01-01

A restoration technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at Oak Ridge National Laboratory (ORNL) is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in Solid Waste Storage Area 6 (SWSA 6) were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability and decreased potential for leachate migration following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. After grouting, soil-penetration tests disclosed that stability had been improved greatly. For example, refusal (defined as > 100 blows to penetrate 1 ft) was encountered in 17 of the 22 tests conducted within the trench area. Mean refusal depths for the two trenches were 3.5 and 2.6 m. Stability of the trench was significantly better than pregrout conditions, and at depths > 2.4 m, the stability was very near that observed in the native soil formation outside the trench. Tests within the trench showed lower stability within this range probably because of the presence of intermediate-sized soil voids (formed during backfilling) that were too small to be penetrated and filled by the conventional cement grout formulation. Hydraulic conductivity within the trench remained very high (>0.1 cm/s) and significantly greater than outside the trench. Postgrout air pressurization tests also revealed a large degree of intervoid linkage within and between the two trenches. To effectively reduce hydraulic conductivity and to develop stability within the upper level of the trench, injection of a clay/microfine cement grout into the upper level of the grouted trench is planned

High‐resolution trench photomosaics from image‐based modeling: Workflow and error analysis

Science.gov (United States)

Reitman, Nadine G.; Bennett, Scott E. K.; Gold, Ryan D.; Briggs, Richard; Duross, Christopher

2015-01-01

Photomosaics are commonly used to construct maps of paleoseismic trench exposures, but the conventional process of manually using image‐editing software is time consuming and produces undesirable artifacts and distortions. Herein, we document and evaluate the application of image‐based modeling (IBM) for creating photomosaics and 3D models of paleoseismic trench exposures, illustrated with a case‐study trench across the Wasatch fault in Alpine, Utah. Our results include a structure‐from‐motion workflow for the semiautomated creation of seamless, high‐resolution photomosaics designed for rapid implementation in a field setting. Compared with conventional manual methods, the IBM photomosaic method provides a more accurate, continuous, and detailed record of paleoseismic trench exposures in approximately half the processing time and 15%–20% of the user input time. Our error analysis quantifies the effect of the number and spatial distribution of control points on model accuracy. For this case study, an ∼87  m2 exposure of a benched trench photographed at viewing distances of 1.5–7 m yields a model with <2  cm root mean square error (rmse) with as few as six control points. Rmse decreases as more control points are implemented, but the gains in accuracy are minimal beyond 12 control points. Spreading control points throughout the target area helps to minimize error. We propose that 3D digital models and corresponding photomosaics should be standard practice in paleoseismic exposure archiving. The error analysis serves as a guide for future investigations that seek balance between speed and accuracy during photomosaic and 3D model construction.

Scattering and extinction from high-aspect-ratio trenches

DEFF Research Database (Denmark)

Roberts, Alexander Sylvester; Søndergaard, Thomas; Chirumamilla, Manohar

2015-01-01

We construct a semi-analytical model describing the scattering, extinction and absorption properties of a high aspect-ratio trench in a metallic film. We find that these trenches act as highly efficient scatterers of free waves. In the perfect conductor limit, which for many metals is approached...

Studies of quaternary deposits in investigation trench OL-TK19 on the Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Huhta, P.

2013-07-01

The Quaternary deposits in investigation trench OL-TK19 were studied by the Geological Survey of Finland in October 2012. Samples for grain size determinations were taken from 3 vertical profiles, placed about 20-25 m apart along the trench. Two till units was sampled separately. The profiles extended from the soil surface down to bedrock. The samples were first dried in the laboratory after which they were sieved. In addition, the grain size distribution of the < 63 μm fraction was analyzed with the Sedigraph 5100 instrument. Sedimentological observations of the sampling profiles were documented in field by drawing them on a field observation form and the profiles were photographed using a digital camera. In addition, the excavated section was photographed along its whole length. The till cover in OL-TK19 consists of two parts. The surface layer of the till is oxidized, brownish grey sandy till, whereas the lower layer is unoxidized, grey silty till. Dark grey silty till as in the bottom of investigation trenches OL-TK13 and OL-TK14 was not found in this trench. The till layers in OL-TK19 was deposited in the last flow phase of the Weichselian continental ice. Bedrock striations indicate that the ice moved in a NW-SE direction. The till beds smooth bedrock topography. The tills showed no signs of disturbance related to bedrock movements. (orig.)

A radiochemical study of sedimentation onto the Japan Trench floor

International Nuclear Information System (INIS)

Yamada, M.; Kitaoka, H.; Tsunogai, S.

1983-01-01

Box cores were taken from the Japan Trench (water depth, 8260 m) and two neighboring shallower stations (water depth, 2970 and 4310 m) and analyzed for uranium isotopes, thorium isotopes, 210 Pb, CaCO 3 , Fe, Mn, Al, and Cu. The 230 Th: 232 Th activity ratios in the top layer (0 to 1 cm) were 12 to 15 at the three stations, indicating no appreciable addition of 230 Th during descent through the water column below 4 km depth. There are no significant differences in the concentrations of 238 U, 232 Th, and 230 Th on a carbonate-free basis at the three stations. The 230 Th: 232 Th activity ratios of the Japan Trench sediments in the upper 30 cm are nearly constant with depth, indicating rapid sedimentation or active vertical mixing of the sediments. The mixing depth of the Japan Trench sediments is estimated to be 7 cm from the vertical distribution of excess 210 Pb. The maximum concentration of 210 Pb in the Japan Trench sediment is at 2- to 3-cm depth. The results suggest that sediment deposited on the shallower slope of the trench slides down and accumulates on the trench floor. (author)

STRENGTHENING OF TRENCH COVER PLATES FOR SWITCHGEAR BUILDING

International Nuclear Information System (INIS)

M.S. RUBEN

2000-01-01

The objective of this calculation is to strengthen the existing trench cover plates of the Electrical Switchgear Building (BLDG 5010) of the Exploratory Studies Facility. A remodeling effort will change the portion of the facility that has the trenches for electrical cables to a craft/shop area. The users of the building will be using a forklift in this area (Clark CGP 30 forklift with a capacity of 3 tons). The trench covers require strengthening to support the wheel loads from the forklift. The output of this calculation will be sketches revising the floor plate details of DWG YMP-025-1-7007-ST103,2. (Details 4 and 5)

Determining the extent of groundwater interference on the performance of infiltration trenches

DEFF Research Database (Denmark)

Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

2015-01-01

Infiltration trenches are widely used in stormwater management, but their capacity decreases when installed in areas with shallow groundwater where infiltration is limited by groundwater drainage. Here the hydrological performance of single infiltration trenches in areas with shallow water tables...... is quantified in terms of their capability to reduce peak flow, peak volume and annual stormwater runoff volume. To simulate the long term hydrological performance of infiltration trenches two different models are employed. The models continuously simulate infiltration rates from infiltration trenches using...... to quantify the impact of parameter variability for each scenario. Statistical analysis of the continuous long term model simulations was used to quantify the hydrological performance of infiltration trenches. Results show that infiltration trenches are affected by groundwater when there is an unsaturated...

Diode having trenches in a semiconductor region

Energy Technology Data Exchange (ETDEWEB)

Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

2016-03-22

An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

Accelerated cleanup of the 316-5 process trenches at the Hanford Site

International Nuclear Information System (INIS)

Henckel, G.C.; Johnson, W.L.

1991-01-01

In October, 1990, the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology signed an Agreement in Principle to accelerate remedial actions on the Hanford Site. Removal of contaminated sediments from the 300 Area (316-5) Process Trenches was one of the three initial candidate locations identified for the accelerated remediation. The trenches have received small quantities of radioactive and hazardous wastes in large volumes of process water (up to 11,360,000 L/day). The trenches are approximately 300 m west of the Columbia River and 7 m above the water table. The trenches are an active interim permitted disposal facility that may remain active for the next few years. In order to reduce the potential for migration of contaminants from the trench sediments into the groundwater, an expedited response action to remove approximately 2,500 m 2 of soil from the active portion of the trenches is being performed. Field activities were initiated in July 1991 with site preparation. The first trench to be excavated was completed by August 15, 1991. Approximately 2 weeks were needed to begin removal activities in the second trench. The second trench should be completed by October 1, 1991, with the subsequent construction of an interim cover over the consolidated materials completed by December 1991

Accelerated cleanup of the 316-5 Process Trenches at the Hanford Site

International Nuclear Information System (INIS)

Henckel, G.C.; Johnson, W.L.

1991-09-01

In October, 1990, the US Department of Energy, the US Environmental Protection Agency, and the Washington State Department of Ecology signed an Agreement in Principle to accelerate remedial actions on the Hanford Site. Removal of contaminated sediments from the 300 Area (316-5) Process Trenches was on of the three initial candidate locations identified for the accelerated remediation. The trenches have received small quantities of radioactive and hazardous wastes in large volumes of process water (up to 11,360,000 L/day). The trenches are approximately 300 m west of the Columbia River and 7 m above the water table. The trenches are an active interim permitted disposal facility that may remain active for the next few years. In order to reduce the potential for migration of contaminants from the trench sediments into the groundwater, an expedited response action to remove approximately 2,500 m 2 of soil from the active portion of the trenches is being performed. Field activities were initiated in July 1991 with site preparation. The first trench to be excavated was completed by August 15, 1991. Approximately 2 weeks were needed to begin removal activities in the second trench. The second trench should be completed by October 1, 1991, with the subsequent construction of an interim cover over the consolidated materials completed by December 1991

Expedited response action proposal for 316-5 process trenches

International Nuclear Information System (INIS)

1991-07-01

A summary of the evaluation of remedial alternatives for the 300 Area Process Trench sediment removal at Hanford is presented. Based on the preliminary technology screening, screening factors, and selection criteria the preferred alternative for the 300 Area Process Trench is to remove and interim stabilize the sediments within the fenced area of the process trenches. This alternative involves proven technologies that are applied easily at this mixed waste site. This alternative removes and isolates contaminated sediments from the active portion of the trenches allowing continued used of the trenches until an inspection and treatment facility is constructed. The alternative does not incorporate any materials or actions that preclude consideration of a technology for final remediation of the operable unit. The estimated initial and annual costs would enable this alternative to be implemented under the guidelines for an EPA- funded ERA ($2 million). Implementation of the alternative can be accomplished with trained personnel using familiar procedures to provide a safe operation that accomplishes the objective for removing a potential source of contamination, thereby reducing potential environmental threat to groundwater. 18 refs., 5 figs., 9 tabs

Project clean city: joint trenching for urban facilities; Projeto cidade limpa: vala tecnica para instalacoes urbanas - sistema infavias

Energy Technology Data Exchange (ETDEWEB)

Silva, Aloisio Pereira da [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

2012-07-01

This study aims to propose a join trench for urban facilities, using concepts related to planning and urban cadastre, sustainability of resource use, and mainly focus on safety during construction, operation and maintenance. The model proposes the replacement of individual construction of facilities of natural gas, potable water, telephone, data transmission and electricity (low and medium voltage) by a system that encompasses all of these facilities in a trench, the deployment may also occur in the same period or if necessary, or at different times, creating flexibility in the system. The security of facilities due to the operational interface between the concessionaires and clients will be ensured by the protected by reinforced concrete structure, designed using the concept of 'fail-safing', derived from the Toyota Production System. The joint trench model was designed from the perspective of sustainability and technological innovation for your future use of the new design of power supply, through the concept of 'Smart Grid' with the use of bidirectional power system transmission and distribution, in decentralized model for generating electricity through cogeneration systems with natural gas. (author)

300 Area Process Trenches Modified Closure/Postclosure Plan

International Nuclear Information System (INIS)

1997-09-01

This chapter provides a brief summary of the contents of each chapter of this plan for the closure of the 300 Area Process Trenches (300 APT) treatment, storage, and/or disposal unit. It also provides background information for this unit and discusses how its closure will be integrated with the remedial action for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 300- FF-1 Operable Unit. The 300 APT is located within the 300 Area of the Hanford Site. This area contained reactor fuel fabrication facilities and research and development laboratories. The 300 APT was constructed and began operations in 1975 as the 316-5 Process Trenches. Effluent was discharged to the trenches by way of the 300 Area process sewer system, which has been the sole source of effluent for the 300 APT. The 316-5 Process Trenches gained Resource Conservation and Recovery Act of 1976 (RCRA) interim status as the 300 APT TSD unit on November 11, 1985. The unit has been administratively closed to discharges of dangerous waste since 1985

Microstructural analysis in the depth direction of a heteroepitaxial AlN thick film grown on a trench-patterned template by nanobeam X-ray diffraction

Science.gov (United States)

Shida, K.; Takeuchi, S.; Tohei, T.; Miyake, H.; Hiramatsu, K.; Sumitani, K.; Imai, Y.; Kimura, S.; Sakai, A.

2018-04-01

This work quantitatively assessed the three-dimensional distribution of crystal lattice distortions in an epitaxial AlN thick film grown on a trench-patterned template, using nanobeam X-ray diffraction. Position-dependent ω-2θ-φ mapping clearly demonstrated local tilting, spacing and twisting of lattice planes as well as fluctuations in these phenomena on a sub-micrometer scale comparable to the pitch of the trench-and-terrace patterning. Analysis of the crystal lattice distortion in the depth direction was performed using a newly developed method in which the X-ray nanobeam diffracted from the sample surface to specific depths can be selectively detected by employing a Pt wire profiler. This technique generated depth-resolved ω-2θ-φ maps confirming that fluctuations in lattice plane tilting and spacing greatly depend on the dislocation distribution and the history of the AlN epitaxial growth on the trench-patterned structure. It was also found that both fluctuations were reduced on approaching the AlN surface and, in particular, were sharply reduced at specific depths in the terrace regions. These sharp reductions are attributed to the formation of sacrificial zones with degraded crystal quality around the trenches and possibly lead to raising the crystal quality near the surface of the AlN film.

The impact of trench defects in InGaN/GaN light emitting diodes and implications for the “green gap” problem

Energy Technology Data Exchange (ETDEWEB)

Massabuau, F. C.-P., E-mail: fm350@cam.ac.uk; Oehler, F.; Pamenter, S. K.; Thrush, E. J.; Kappers, M. J.; Humphreys, C. J.; Oliver, R. A. [Department of Materials Science and Metallurgy, University of Cambridge, 22 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Davies, M. J.; Dawson, P. [Photon Science Institute, School of Physics and Astronomy, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Kovács, A.; Dunin-Borkowski, R. E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Leo-Brandt- Straße, D-52425 Jülich (Germany); Williams, T.; Etheridge, J. [Monash Centre for Electron Microscopy, Monash University, Clayton Campus, VIC 3800 (Australia); Hopkins, M. A.; Allsopp, D. W. E. [Department of Electronic and Electrical Engineering, University of Bath, Bath BA2 7AY (United Kingdom)

2014-09-15

The impact of trench defects in blue InGaN/GaN light emitting diodes (LEDs) has been investigated. Two mechanisms responsible for the structural degradation of the multiple quantum well (MQW) active region were identified. It was found that during the growth of the p-type GaN capping layer, loss of part of the active region enclosed within a trench defect occurred, affecting the top-most QWs in the MQW stack. Indium platelets and voids were also found to form preferentially at the bottom of the MQW stack. The presence of high densities of trench defects in the LEDs was found to relate to a significant reduction in photoluminescence and electroluminescence emission efficiency, for a range of excitation power densities and drive currents. This reduction in emission efficiency was attributed to an increase in the density of non-radiative recombination centres within the MQW stack, believed to be associated with the stacking mismatch boundaries which form part of the sub-surface structure of the trench defects. Investigation of the surface of green-emitting QW structures found a two decade increase in the density of trench defects, compared to its blue-emitting counterpart, suggesting that the efficiency of green-emitting LEDs may be strongly affected by the presence of these defects. Our results are therefore consistent with a model that the “green gap” problem might relate to localized strain relaxation occurring through defects.

The impact of trench defects in InGaN/GaN light emitting diodes and implications for the “green gap” problem

International Nuclear Information System (INIS)

Massabuau, F. C.-P.; Oehler, F.; Pamenter, S. K.; Thrush, E. J.; Kappers, M. J.; Humphreys, C. J.; Oliver, R. A.; Davies, M. J.; Dawson, P.; Kovács, A.; Dunin-Borkowski, R. E.; Williams, T.; Etheridge, J.; Hopkins, M. A.; Allsopp, D. W. E.

2014-01-01

The impact of trench defects in blue InGaN/GaN light emitting diodes (LEDs) has been investigated. Two mechanisms responsible for the structural degradation of the multiple quantum well (MQW) active region were identified. It was found that during the growth of the p-type GaN capping layer, loss of part of the active region enclosed within a trench defect occurred, affecting the top-most QWs in the MQW stack. Indium platelets and voids were also found to form preferentially at the bottom of the MQW stack. The presence of high densities of trench defects in the LEDs was found to relate to a significant reduction in photoluminescence and electroluminescence emission efficiency, for a range of excitation power densities and drive currents. This reduction in emission efficiency was attributed to an increase in the density of non-radiative recombination centres within the MQW stack, believed to be associated with the stacking mismatch boundaries which form part of the sub-surface structure of the trench defects. Investigation of the surface of green-emitting QW structures found a two decade increase in the density of trench defects, compared to its blue-emitting counterpart, suggesting that the efficiency of green-emitting LEDs may be strongly affected by the presence of these defects. Our results are therefore consistent with a model that the “green gap” problem might relate to localized strain relaxation occurring through defects.

Corrrective action decision document for the Cactus Spring Waste Trenches (Corrective Action Unit No. 426). Revision No. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

The Corrective Action Decision Document (CADD) for the Cactus Spring Waste Trenches (Corrective Action Unit [CAU] No. 426) has been prepared for the US Department of Energy`s (DOE) Nevada Environmental Restoration Project. This CADD has been developed to meet the requirements of the Federal Facility Agreement and Consent Order (FFACO) of 1996, stated in Appendix VI, {open_quotes}Corrective Action Strategy{close_quotes} (FFACO, 1996). The Cactus Spring Waste Trenches Corrective Action Site (CAS) No. RG-08-001-RG-CS is included in CAU No. 426 (also referred to as the {open_quotes}trenches{close_quotes}); it has been identified as one of three potential locations for buried, radioactively contaminated materials from the Double Tracks Test. The trenches are located on the east flank of the Cactus Range in the eastern portion of the Cactus Spring Ranch at the Tonopah Test Range (TTR) in Nye County, Nevada, on the northern portion of Nellis Air Force Range. The TTR is approximately 225 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air and approximately 56 km (35 mi) southeast of Tonopah, Nevada, by road. The trenches were dug for the purpose of receiving waste generated during Operation Roller Coaster, primarily the Double Tracks Test. This test, conducted in 1963, involved the use of live animals to assess the biological hazards associated with non-nuclear detonation of plutonium-bearing devices (i.e., inhalation uptake of plutonium aerosol). The CAS consists of four trenches that received solid waste and had an overall impacted area of approximately 36 meters (m) (120 feet [ft]) long x 24 m (80 ft) wide x 3 to 4.5 m (10 to 15 ft) deep. The average depressions at the trenches are approximately 0.3 m (1 ft) below land surface.

Studies of quaternary deposits in investigation trench OL-TK17 on the Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Huhta, P.

2010-06-01

The Quaternary deposits in investigation trench OL-TK17 were studied by the Geological Survey of Finland in summer 2009. Samples for grain size determinations were taken from 13 vertical profiles, placed about 25 m apart along the trench, where bedrock didn't reach surface. Profiles 5 and 6 were done by the side of the trench because of that. Each till bed was sampled separately. The profiles extended from the soil surface down to bedrock. The samples were first dried in the laboratory after which they were sieved. In addition, the grain size distribution of the < 63 μm fraction was analyzed with the Sedigraph 5100 instrument. Sedimentological observations of the sampling profiles were documented in field by drawing them on a field observation form and the profiles were photographed using a digital camera. In addition, the excavated section was photographed along its whole length. The till cover in OL-TK17 consists of two parts. The surface layer of the upper till is oxidized, brown till, whereas the lower layer is unoxidized, grey till. The lower till has been preserved in bedrock depressions. The lower till is compact, dark grey silty till with more than 19 % of clay-size material (under 0.002 mm). The upper till in OL-TK17 was deposited in the last flow phase of the Weichselian continental ice. Bedrock striations indicate that the ice moved in a WNW-ESE direction. The till beds level out the bedrock topography. Weathered, broken bedrock was found in two places at the bottom of the trench near sampling profiles 08, 09 and 10. No signs of postglacial faults were detected either in the tills or in the exposed bedrock. The tills showed no signs of disturbance related to bedrock movements, only icepressed cracks were found in the lower silty compact till over broken bedrock. (orig.)

Frost seen on Snow White Trench

Science.gov (United States)

2008-01-01

The Surface Stereo Imager (SSI) on NASA's Phoenix Mars Lander took this shadow-enhanced false color image of the 'Snow White' trench, on the eastern end of Phoenix's digging area. The image was taken on Sol 144, or the 144th day of the mission, Oct. 20, 2008. Temperatures measured on Sol 151, the last day weather data were received, showed overnight lows of minus128 Fahrenheit (minus 89 Celsius) and day time highs in the minus 50 F (minus 46 C) range. The last communication from the spacecraft came on Nov. 2, 2008. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Subsidence evaluation in 218-E-E12B, trench 38

International Nuclear Information System (INIS)

Streit, J.J.

1995-01-01

An area in Trench 38 of the 218-E-12B Burial Ground has been gradually sinking over the past few years. The area spans the width of the trench and extends approximately 80 feet down the trench. The depth of the depression is approximately 3 feet in the center and gradually rises to existing grade at the trench edge. It has been determined that the most likely cause of the subsidence is decomposition of buried waste material. Fifty-six percent of the waste buried in the subject area is decomposable and has been in the ground for nine years. Waste packaging is largely plastic lined dump trucks and fiberboard boxes. It is recommended that this area be treated with dynamic compaction to stabilize the waste and minimize the reoccurrence of subsidence in this area

Project clean city: joint trenching for urban facilities; Projeto cidade limpa: vala tecnica para instalacoes urbanas - sistema infavias

Energy Technology Data Exchange (ETDEWEB)

Silva, Aloisio Pereira da [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil)

2012-07-01

This study aims to propose a join trench for urban facilities, using concepts related to planning and urban cadastre, sustainability of resource use, and mainly focus on safety during construction, operation and maintenance. The model proposes the replacement of individual construction of facilities of natural gas, potable water, telephone, data transmission and electricity (low and medium voltage) by a system that encompasses all of these facilities in a trench, the deployment may also occur in the same period or if necessary, or at different times, creating flexibility in the system. The security of facilities due to the operational interface between the concessionaires and clients will be ensured by the protected by reinforced concrete structure, designed using the concept of 'fail-safing', derived from the Toyota Production System. The joint trench model was designed from the perspective of sustainability and technological innovation for your future use of the new design of power supply, through the concept of 'Smart Grid' with the use of bidirectional power system transmission and distribution, in decentralized model for generating electricity through cogeneration systems with natural gas. (author)

In situ grouting of a low-level radioactive waste trench

International Nuclear Information System (INIS)

Spence, R.D.; Godsey, T.T.; McDaniel, E.W.

1987-11-01

A shallow land burial trench containing low level radioactive waste was injected with a particulate grout to help control subsidence and radionuclide migration. The trench's accessible voids have been estimated at 20 vol %, and most of these voids appear to have been filled with grout. This injection was accomplished with a simple, labor intensive technique, and an inexperienced crew at an estimated cost of about $55,000. The grout costs $0.21/gal and 8081 gal was injected into the trench. 5 refs., 10 figs., 4 tabs

Trench Advance By the Subduction of Buoyant Features - Application to the Izu-Bonin-Marianas Arc

Science.gov (United States)

Goes, S. D. B.; Fourel, L.; Morra, G.

2014-12-01

Most subduction trenches retreat, not only today but throughout the Cenozoic. However, a few trenches clearly advance during part of the evolution, including Izu-Bonin Marianas (IBM) and Kermadec. Trench retreat is well understood as a basic consequence of slab pull, but it is debated what causes trench advance. The IBM trench underwent a complex evolution: right after its initiation, it rotated clockwise, leading to very fast retreat in the north and slow retreat in the south. But since 10-15 Ma, IBM trench motions have switched to advance at the southern end, and since 5 Ma also the northern end is advancing. Based on 2-D subduction models, it has been proposed proposed that the change in age of the subducting plate at the IBM trench (from 40-70 m.y. at the initiation of the trench 45 m.y. ago to 100-140 m.y. lithosphere subducting at the trench today) and its effect on plate strength could explain the transition from trench retreat to trench advance, and that the age gradient (younger in the north and older in the south) could explain the rotation of the trench. However, with new 3-D coupled fluid-solid subduction model where we can include such lateral age gradients, we find that this does not yield the observed behaviour. Instead, we propose an alternative mechanism, involving the subduction of the buoyant Caroline Island Ridge at the southern edge of the Mariana trench and show that it can explain both trench motion history and the current morphology of the IBM slab as imaged by seismic tomography.

Long-term safety assessment of trench-type surface repository at Chernobyl, Ukraine - computer model and comparison with results from simplified models

International Nuclear Information System (INIS)

Haverkamp, B.; Krone, J.; Shybetskyi, I.

2013-01-01

The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, the surface repository for solid low and intermediate level waste (LILW) is still being operated but its maximum capacity is nearly reached. Long-existing plans for increasing the capacity of the facility shall be implemented in the framework of the European Commission INSC Programme (Instrument for Nuclear Safety Co-operation). Within the first phase of this project, DBE Technology GmbH prepared a safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) for a future extended facility based on the planned enlargement. In addition to a detailed mathematical model, also simplified models have been developed to verify results of the former one and enhance confidence in the results. Comparison of the results show that - depending on the boundary conditions - simplifications like modeling the multi trench repository as one generic trench might have very limited influence on the overall results compared to the general uncertainties associated with respective long-term calculations. In addition to their value in regard to verification of more complex models which is important to increase confidence in the overall results, such simplified models can also offer the possibility to carry out time consuming calculations like probabilistic calculations or detailed sensitivity analysis in an economic manner. (authors)

Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

International Nuclear Information System (INIS)

1997-02-01

This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the CAU No. 426, which includes the Cactus Spring Waste Trenches, CAS No. RG-08-001-RG-CS. The Cactus Spring Waste Trenches are located at the Tonopah Test Range (TTR) which is part of the Nellis Air Force Range, approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action

A parylene-filled-trench technique for thermal isolation in silicon-based microdevices

International Nuclear Information System (INIS)

Lei Yinhua; Wang Wei; Li Ting; Jin Yufeng; Zhang Haixia; Li Zhihong; Yu Huaiqiang; Luo Yingcun

2009-01-01

Microdevices prepared in a silicon substrate have been widely used in versatile fields due to the matured silicon-based microfabrication technique and the excellent physical properties of silicon material. However, the high thermal conductivity of silicon restricts its application in most thermal microdevices, especially devices comprising different temperature zones. In this work, a parylene-filled-trench technique was optimized to realize high-quality thermal isolation in silicon-based microdevices. Parylene C, a heat transfer barricading material, was deposited on parallel high-aspect-ratio trenches, which surrounded the isolated target zones. After removing the remnant silicon beneath the trenches by deep reactive ion etching from the back side, a high-quality heat transfer barrier was obtained. By using narrow trenches, only 5 µm thick parylene was required for a complete filling, which facilitated multi-layer interconnection thereafter. The parylene filling performance inside the high-aspect-ratio trench was optimized by two approaches: multiple etch–deposition cycling and trench profile controlling. A 4 × 6 array, in which each unit was kept at a constant temperature and was well thermally isolated individually, was achieved on a silicon substrate by using the present parylene-filled-trench technique. The preliminary experimental results indicated that the present parylene-filled-trench structure exhibited excellent thermal isolation performance, with a very low power requirement of 0.134 mW (K mm 2 ) −1 for heating the isolated silicon unit and a high thermal isolation efficiency of 72.5% between two adjacent units. Accompanied with high-quality isolation performance, the microdevices embedded the present parylene-filled-trench structure to retain a strong mechanical connection larger than 400 kPa between two isolated zones, which is very important for a high-reliability-required micro-electro-mechanical-system (MEMS) device. Considering its room

In situ grouting of low-level burial trenches with a cement-based grout

International Nuclear Information System (INIS)

Francis, C.W.; Spalding, B.P.

1991-01-01

A restoration technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at Oak Ridge National Laboratory (ORNL) is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in Solid Waste Storage Area 6 (SWSA 6) were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability and decreased potential for leachate migration following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. 7 refs., 3 figs., 5 tabs

Formation mechanism of Al-depleted bands in MOVPE-AlGaN layer on GaN template with trenches

Energy Technology Data Exchange (ETDEWEB)

Kuwano, Noriyuki [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Department of Applied Science for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Ezaki, Tetsuya; Kurogi, Takuya [Department of Applied Science for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Miyake, Hideto; Hiramatsu, Kazumasa [Department of Electrical and Electronic Engineering, Mie University, Tsu, Mie 514-8507 (Japan)

2010-07-15

A microstructure in an AlGaN/GaN layer was analyzed in detail by means of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with special attention to the formation of steps on the surface. The AlGaN layer was grown by MOVPE on a GaN template with periodic trenches. It was revealed that there formed were Al-depleted bands in the AlGaN layer. These bands were generated from rather lower regions in the AlGaN layer or those above the trenches, and run upwards. Some of them reached the top surface to connect a macro step. The formation mechanism of the Al-depleted region is discussed in terms of thermodynamics. If the total bonding energy of atoms on the macro step of surface is assumed to be smaller than that of atoms on a flat surface, the Al-depletion can be explained provided that the local equilibrium in concentration is conserved during the growth of AlGaN layer. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Three-dimensional imaging, change detection, and stability assessment during the centerline trench levee seepage experiment using terrestrial light detection and ranging technology, Twitchell Island, California, 2012

Science.gov (United States)

Bawden, Gerald W.; Howle, James; Bond, Sandra; Shriro, Michelle; Buck, Peter

2014-01-01

region that has a maximum subsidence of 3.5 cm over an area 0.75 m wide and 8.1 m long and is associated with a number of small fractures in the pavement that are predominately north-south-trending and parallel to the trench. We determined that there was no significant motion of the levee flank during the last week of the seepage test. We also determined biomorphic parameters for the landside tree, such as the 3D positioning on the levee, tree height, levee parallel/perpendicular cross sectional area, and canopy centroid. These biomorphic parameters were requested to support a University of California Berkeley team studying seepage and stability on the levee. A gridded, 2-cm bare-earth digital elevation model of the levee crown and the landside levee flank from the final terrestrial lidar (T-Lidar) survey provided detailed topographic data for future assessment. Because the T-Lidar was not integrated into the project design, other than an initial courtesy dataset to help characterize the levee surface, our ability to contribute to the overall science goals of the seepage test was limited. Therefore, our analysis focused on developing data collection and processing methodology necessary to align ultra high-resolution T-Lidar data (with an average spot spacing 2–3 millimeters on the levee crown) from several instrument setup locations to detect, measure, and characterize dynamic centimeter-scale deformation and surface changes during the seepage test.

Scaling Rule for Very Shallow Trench IGBT toward CMOS Process Compatibility

OpenAIRE

Tanaka, Masahiro; Omura, Ichiro

2012-01-01

Deep trench gate is used for latest IGBT to improve device performance. By large difference from deep submicron CMOS structure, there is no process compatibility among CMOS device and trench gate IGBT. We propose IGBT scaling rule for shrinking IGBT cell structure both horizontally and vertically. The scaling rule is theoretically delivered by structure based equations. Device performance improvement was also predicted by TCAD simulations even with very shallow trench gate. The rule enables t...

Field and laboratory investigations on pavement backfilling material for micro-trenching in cold regions

Directory of Open Access Journals (Sweden)

Leila Hashemian

2017-07-01

Full Text Available Micro-trenching is an innovative utility installation method that involves creating a narrow trench to place cable or conduit in the road pavement. Compared to other installation methods, micro-trenching provides minimal disturbance to the community and surrounding environment. Despite the advantages of micro-trenching, it is not widely accepted by municipalities because of its potential to damage the existing pavement. Quality of backfilling is an important factor in long-term sustainability of the micro-trench, particularly in cold regions. This paper investigates the performance of two typical micro-trench backfilling methods in cold climates by studying a pilot project in a parking lot in Edmonton, Alberta, followed by a laboratory evaluation of the material used. For this purpose, the installations were monitored through ground-penetrating radar, optical time-domain reflectometer, and visual observations for three years. The monitoring results revealed that conduit had significant vertical movement inside the trench; several premature failures were also observed in the backfilling material. Laboratory investigation showed that the backfilling material did not meet the criteria for use in cold climates, and micro-trench performance could be enhanced using alternative materials. Keywords: Micro-trench, Pavement backfilling material, Fiber optic installation, Ground-penetrating radar

Technology development for the design of shallow land burial facilities at semiarid sites

International Nuclear Information System (INIS)

Abeele, W.V.; Nyhan, J.W.; Drennon, B.J.

1987-01-01

Three experiments are described: effectiveness of a moisture barrier and the physical basis for capillary barriers; trench cap designs for long term stabilization including biointrusion barrier testing; and joint DOE/NRC tracer migration experiment. In the first, a barrier concept known as the wick effect is being field tested to control the movement of water on top of and around shallow land burial trenches. The barrier is composed of bentonite and tuff. In the second, the performance is measured of a conventional and an improved trench cover design on surface water dynamics, in limiting biological intrusion, and under both natural and enhanced precipitation regimes. The third experiment evaluates leaching and transport of solutes in sandy silt backfill used in shallow land burial at Los Alamos and compares results with laboratory-derived parameter estimates. 6 references, 4 figures, 2 tables

Performance monitoring of an improved disposal trench in a humid environment in a fractured geology

International Nuclear Information System (INIS)

Mills, D.; Razor, J.

1988-01-01

An engineering evaluation of an improved disposal trench at the Maxey Flats Waste Disposal Site is being conducted in order to demonstrate the feasibility of a burial trench suitable for use at a site in a humid environment and underlain by complex and fractured geologic media. This demonstration is one of several proposed final site stabilization alternatives which will have to be evaluated prior to final site closure. Due to requirements in the Central Midwest Compact Commission, no waste generated as a result of the site closure may be disposed in the Commission's disposal site. Hence, the waste will be disposed on-site. The demonstration trench was constructed and filled with waste during the fall of 1985 with final trench capping being completed in July 1986. Since that time the trench has been evaluated utilizing trench settlement monument elevations, leachate production measurements, leachate radionuclide analysis, chemical tracer analysis and trench water balance. Measurements performed to date indicated that the trench lower infiltration barrier has a permeability of about 1E-7 cm/sec. Water balance measurements indicated that less than one percent of the total rainfall crossed the trench capillary barrier. No settlement of the trench cap has been observed. No liquid has appeared in the leachate collection and monitoring sumps

Field demonstration of in situ grouting of radioactive solid waste burial trenches with polyacrylamide

International Nuclear Information System (INIS)

Spalding, B.P.; Fontaine, T.A.

1990-01-01

Demonstrations of in situ grouting with polyacrylamide were carried out on two undisturbed burial trenches and one dynamically compacted burial trench in Solid Waste Storage Area (SWSA) 6 at Oak Ridge National Laboratory (ORNL). The injection of polyacrylamide was achieved quite facilely for the two undisturbed burial trenches which were filled with grout, at typical pumping rates of 95 L/min, in several batches injected over several days. The compacted burial trench, however, failed to accept grout at more than 1.9 L/min even when pressure was applied. Thus, it appears that burial trenches, stabilized by dynamic compaction, have a permeability too low to be considered groutable. The water table beneath the burial trenches did not respond to grout injections indicating a lack of hydrologic connection between fluid grout and the water table which would have been observed if the grout failed to set. Because grout set times were adjusted to less than 60 min, the lack of hydrologic connection was not surprising. Postgrouting penetration testing revealed that the stability of the burial trenches was increased from 26% to 79% that measured in the undisturbed soil surrounding the trenches. In situ permeation tests on the grouted trenches indicated a significant reduction in hydraulic conductivity of the trench contents from a mean of 2.1 x 10 -3 to 1.85 x 10 -5 cm/s. Preliminary observations indicated that grouting with polyacrylamide is an excellent method for both improved stability and hydrologic isolation of radioactive waste and its incidental hazardous constituents

A Generic Safety Assessment Model for a Trench Type LILW Repository

International Nuclear Information System (INIS)

Lee, Youn-Myoung; Choi, Hee-Joo

2015-01-01

This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool

A Generic Safety Assessment Model for a Trench Type LILW Repository

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn-Myoung; Choi, Hee-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool.

Interim-status groundwater monitoring plan for the 216-B-63 trench. Revision 1

Energy Technology Data Exchange (ETDEWEB)

Sweeney, M.D.

1995-06-13

This document outlines the groundwater monitoring plan for interim-status detection-level monitoring of the 216-B-63 Trench. This is a revision of the initial groundwater monitoring plan prepared for Westinghouse Hanford Company (WHC) by Bjornstad and Dudziak (1989). The 216-B-63 Trench, located at the Hanford Site in south-central Washington State, is an open, unlined, earthern trench approximately 1.2 m (4 ft) wide at the bottom, 427 m (1400 ft) long, and 3 m (10 ft) deep that received wastewater containing hazardous waste and radioactive materials from B Plant, located in the 200 East Area. Liquid effluent discharge to the 216-B-63 Trench began in March 1970 and ceased in February 1992. The trench is now managed by Waste Tank Operations.

Interim-status groundwater monitoring plan for the 216-B-63 trench. Revision 1

International Nuclear Information System (INIS)

Sweeney, M.D.

1995-01-01

This document outlines the groundwater monitoring plan for interim-status detection-level monitoring of the 216-B-63 Trench. This is a revision of the initial groundwater monitoring plan prepared for Westinghouse Hanford Company (WHC) by Bjornstad and Dudziak (1989). The 216-B-63 Trench, located at the Hanford Site in south-central Washington State, is an open, unlined, earthern trench approximately 1.2 m (4 ft) wide at the bottom, 427 m (1400 ft) long, and 3 m (10 ft) deep that received wastewater containing hazardous waste and radioactive materials from B Plant, located in the 200 East Area. Liquid effluent discharge to the 216-B-63 Trench began in March 1970 and ceased in February 1992. The trench is now managed by Waste Tank Operations

Geological mapping of investigation trench OL-TK18 at the Olkiluoto study site, Eurajoki, SW Finland

Energy Technology Data Exchange (ETDEWEB)

Engstroem, J. [GTK Geological Survey of Finland, Espoo (Finland)

2012-04-15

measured fracture being 7.90 m. Fracture fillings include hematite, chlorite, biotite and muscovite. A few fracture surfaces also contain calcite, clay, pyrite, quartz, and illite. The thickness of the fillings varies between 0.1 - 60 mm and the average thickness is 1.7 mm. The trench contains two big faults, one with a distinct fault core of quartz, calcite and chlorite, and having a NW-SE strike and a moderate dip towards the NE. The other one is parallel to the D{sub 4} ductile deformation domain, having a NE-SW strike and a moderate dip to the SW, showing totally altered and sheared rock. A Q-classification for the investigation trench has been made for every mapping section and the quality varies from good to exceptionally good. The average Q-quality of the rocks is exceptionally good, indicating that no major brittle deformation zone intersects the trench. (orig.)

Electrostatic potential fluctuation induced by charge discreteness in a nanoscale trench

International Nuclear Information System (INIS)

Lee, Taesang; Kim, S. S.; Jho, Y. S.; Park, Gunyoung; Chang, C. S.

2007-01-01

A simplified two-dimensional Monte Carlo simulation is performed to estimate the charging potential fluctuations caused by strong binary Coulomb interactions between discrete charged particles in nanometer scale trenches. It is found that the discrete charge effect can be an important part of the nanoscale trench research, inducing scattering of ion trajectories in a nanoscale trench by a fluctuating electric field. The effect can enhance the ion deposition on the side walls and disperse the material contact energy of the incident ions, among others

Wavelength-dependent Crosstalk in Trench-Assisted Multi-Core Fibers

DEFF Research Database (Denmark)

Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

2014-01-01

Analytical expressions for wavelength-dependent crosstalk in homogeneous trench-assisted multi-core fibers are derived. The calculated results from the expressions agree well with the numerical simulation results based on finite element method.......Analytical expressions for wavelength-dependent crosstalk in homogeneous trench-assisted multi-core fibers are derived. The calculated results from the expressions agree well with the numerical simulation results based on finite element method....

Near-trench slip potential of megaquakes evaluated from fault properties and conditions

Science.gov (United States)

Hirono, Tetsuro; Tsuda, Kenichi; Tanikawa, Wataru; Ampuero, Jean-Paul; Shibazaki, Bunichiro; Kinoshita, Masataka; Mori, James J.

2016-01-01

Near-trench slip during large megathrust earthquakes (megaquakes) is an important factor in the generation of destructive tsunamis. We proposed a new approach to assessing the near-trench slip potential quantitatively by integrating laboratory-derived properties of fault materials and simulations of fault weakening and rupture propagation. Although the permeability of the sandy Nankai Trough materials are higher than that of the clayey materials from the Japan Trench, dynamic weakening by thermally pressurized fluid is greater at the Nankai Trough owing to higher friction, although initially overpressured fluid at the Nankai Trough restrains the fault weakening. Dynamic rupture simulations reproduced the large slip near the trench observed in the 2011 Tohoku-oki earthquake and predicted the possibility of a large slip of over 30 m for the impending megaquake at the Nankai Trough. Our integrative approach is applicable globally to subduction zones as a novel tool for the prediction of extreme tsunami-producing near-trench slip. PMID:27321861

Inversion kinematics at deep-seated gravity slope deformations revealed by trenching techniques

OpenAIRE

Pasquaré Mariotto, Federico; Tibaldi, Alessandro

2016-01-01

We compare data from three deep-seated gravitational slope deformations (DSGSDs) where palaeoseismological techniques were applied in artificial trenches. At all trenches, located in metamorphic rocks of the Italian Alps, there is evidence of extensional deformation given by normal movements along slip planes dipping downhill or uphill, and/or fissures, as expected in gravitational failure. However, we document and illustrate – with the aid of trenching – evidenc...

Determining the extent of groundwater interference on the performance of infiltration trenches

OpenAIRE

Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Wong, Tony; Binning, Philip John

2015-01-01

Infiltration trenches are widely used in stormwater management, but their capacity decreases when installed in areas with shallow groundwater where infiltration is limited by groundwater drainage. Here the hydrological performance of single infiltration trenches in areas with shallow water tables is quantified in terms of their capability to reduce peak flow, peak volume and annual stormwater runoff volume. To simulate the long term hydrological performance of infiltration trenches two differ...

Field and laboratory investigations on pavement backfilling material for micro-trenching in cold regions

OpenAIRE

Leila Hashemian; Mohammad Rezaei; Alireza Bayat

2017-01-01

Micro-trenching is an innovative utility installation method that involves creating a narrow trench to place cable or conduit in the road pavement. Compared to other installation methods, micro-trenching provides minimal disturbance to the community and surrounding environment. Despite the advantages of micro-trenching, it is not widely accepted by municipalities because of its potential to damage the existing pavement. Quality of backfilling is an important factor in long-term sustainability...

Mariana Trench Bathymetric Digital Elevation Model

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) created a bathymetric digital elevation model (DEM) for the Mariana Trench and adjacent seafloor in the Western...

Numerical investigation of a double-junction a:SiGe thin-film solar cell including the multi-trench region

International Nuclear Information System (INIS)

Kacha, K.; Djeffal, F.; Ferhati, H.; Arar, D.; Meguellati, M.

2015-01-01

We present a new approach based on the multi-trench technique to improve the electrical performances, which are the fill factor and the electrical efficiency. The key idea behind this approach is to introduce a new multi-trench region in the intrinsic layer, in order to modulate the total resistance of the solar cell. Based on 2-D numerical investigation and optimization of amorphous SiGe double-junction (a-Si:H/a-SiGe:H) thin film solar cells, in the present paper numerical models of electrical and optical parameters are developed to explain the impact of the multi-trench technique on the improvement of the double-junction solar cell electrical behavior for high performance photovoltaic applications. In this context, electrical characteristics of the proposed design are analyzed and compared with conventional amorphous silicon double-junction thin-film solar cells. (paper)

Geophysical investigation of the 116-H-1 liquid waste disposal trench, 100-HR-1 operable unit

International Nuclear Information System (INIS)

Bergstrom, K.A.; Mitchell, T.H.

1996-04-01

A geophysical investigation and data integration were conducted for the 116-H-1 Liquid Waste Disposal Trench, which is located in the 100-HR-1 Operable Unit. The 116-H-1 Liquid Waste Disposal Trench is also known as the 107-H Liquid Waste Disposal Trench, the 107-H Rupture Effluent Trench, and the 107-H Trench (Deford and Einan 1995). The trench was primarily used to hold effluent from the 107-H Retention Basin that had become radioactive from contact with ruptured fuel elements. The effluent may include debris from the ruptured fuel elements (Koop 1964). The 116-H-1 Liquid Waste Disposal Trench was also used to hold water and sludge from the 107-H Retention Basin during the basin's deactivation in 1965

Filling high aspect ratio trenches by superconformal chemical vapor deposition: Predictive modeling and experiment

Science.gov (United States)

Wang, Wenjiao B.; Abelson, John R.

2014-11-01

Complete filling of a deep recessed structure with a second material is a challenge in many areas of nanotechnology fabrication. A newly discovered superconformal coating method, applicable in chemical vapor deposition systems that utilize a precursor in combination with a co-reactant, can solve this problem. However, filling is a dynamic process in which the trench progressively narrows and the aspect ratio (AR) increases. This reduces species diffusion within the trench and may drive the component partial pressures out of the regime for superconformal coating. We therefore derive two theoretical models that can predict the possibility for filling. First, we recast the diffusion-reaction equation for the case of a sidewall with variable taper angle. This affords a definition of effective AR, which is larger than the nominal AR due to the reduced species transport. We then derive the coating profile, both for superconformal and for conformal coating. The critical (most difficult) step in the filling process occurs when the sidewalls merge at the bottom of the trench to form the V shape. Experimentally, for the Mg(DMADB)2/H2O system and a starting AR = 9, this model predicts that complete filling will not be possible, whereas experimentally we do obtain complete filling. We then hypothesize that glancing-angle, long-range transport of species may be responsible for the better than predicted filling. To account for the variable range of species transport, we construct a ballistic transport model. This incorporates the incident flux from outside the structure, cosine law re-emission from surfaces, and line-of-sight transport between internal surfaces. We cast the transport probability between all positions within the trench into a matrix that represents the redistribution of flux after one cycle of collisions. Matrix manipulation then affords a computationally efficient means to determine the steady-state flux distribution and growth rate for a given taper angle. The

EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

International Nuclear Information System (INIS)

Ernest E. Carter, P.E.

2002-01-01

EarthSaw(trademark) is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file

Fire hazard analysis for the Westinghouse Hanford Company managed low-level mixed waste Trench 31 and 34

International Nuclear Information System (INIS)

Howard, B.J.

1995-01-01

This analysis is to assess comprehensively the risks from fire within the new lined landfills, provided by W-025 and designated Trench 31 and 34 of Burial Ground 218-W-5; they are located in the 200 West area of the Hanford Site, and are designed to receive low-level mixed waste

Selective epitaxial growth properties and strain characterization of Si1- x Ge x in SiO2 trench arrays

Science.gov (United States)

Koo, Sangmo; Jang, Hyunchul; Ko, Dae-Hong

2017-04-01

In this study, we investigated the formation of a Si1- x Ge x fin structure in SiO2 trench arrays via an ultra-high-vacuum chemical-vapor deposition (UHV-CVD) selective epitaxial growth (SEG) process. Defect generation and microstructures of Si1- x Ge x fin structures with different Ge concentrations ( x = 0.2, 0.3 and 0.45) were examined. In addition, the strain evolution of a Si1- x Ge x fin structure was analyzed by using reciprocal space mapping (RSM). An (111) facet was formed from the Si1- x Ge x epi-layer and SiO2 trench wall interface to minimize the interface and the surface energy. The Si1- x Ge x fin structures were fully relaxed along the direction perpendicular to the trenches regardless of the Ge concentration. On the other hand, the fin structures were fully or partially strained along the direction parallel to the trenches depending on the Ge concentration: fully strained Si0.8Ge0.2 and Si0.7Ge0.3, and a Si0.55Ge0.45 strain-relaxed buffer. We further confirmed that the strain on the Si1- x Ge x fin structures remained stable after oxide removal and H2/N2 post-annealing.

Geophysical investigation of trench 4, Burial Ground 218-W-4C, 200 west area

International Nuclear Information System (INIS)

Kiesler, J.P.

1994-01-01

This report contains the results of a geophysical investigation conducted to characterize Trench 4, located in Burial Ground 218-W-4C, 200 West Area. Trench 4 is where transuranic (TRU) waste is stored. The primary objective of these geophysical investigations was to determine the outer edges of the trench/modules and select locations for plate-bearing tests. The test locations are to be 5 to 8 ft. beyond the edges of the trench. Secondary objectives include differentiating between the different types of waste containers within a given trench, determining the amount of soil cover over the waste containers, and to locate the module boundaries. Ground-penetrating radar (GPR) and electromagnetic induction (EMI) were the methods selected for this investigation

Durability test of geomembrane liners presumed to avail near surface disposal facilities for low-level waste generated from research, industrial and medical facilities

International Nuclear Information System (INIS)

Nakata, Hisakazu; Amazawa, Hiroya; Sakai, Akihiro; Kurosawa, Ryohei; Sakamoto, Yoshiaki; Kanno, Naohiro; Kashima, Takahiro

2014-02-01

The Low-level Radioactive Waste Disposal Project Center will construct near surface disposal facilities for radioactive wastes from research, industrial and medical facilities. The disposal facilities consist of “concrete pit type” for low-level radioactive wastes and “trench type” for very low level radioactive wastes. As for the trench type disposal facility, two kinds of facility designs are on projects – one for a normal trench type disposal facility without any of engineered barriers and the other for a trench type disposal facility with geomembrane liners that could prevent from causing environmental effects of non radioactive toxic materials contained in the waste packages. The disposal facility should be designed taking basic properties of durability on geomembrane liners into account, for it is exposed to natural environment on a long-term basis. This study examined mechanical strength and permeability properties to assess the durability on the basis of an indoor accelerated exposure experiment targeting the liner materials presumed to avail the conceptual design so far. Its results will be used for the basic and detailed design henceforth by confirming the empirical degradation characteristic with the progress of the exposure time. (author)

Trench water chemistry at commercially operated low-level radioactive waste disposal sites

International Nuclear Information System (INIS)

Pietrzak, R.F.; Dayal, R.; Kinsley, M.T.; Clinton, J.; Czyscinski, K.S.; Weiss, A.J.

1982-01-01

Water samples from the disposal trenches of two low-level radioactive-waste-disposal sites were analyzed for their inorganic, organic, and radionuclide contents. Since oxidation of the trench waters can occur during their movement along the groundwater flow path, experiments were performed to measure the chemical and physical changes that occur in these waters upon oxidation. Low concentrations of chelating agents, shown to exist in trench waters, may be responsible for keeping radionuclides, particularly 60 Co, in solution. 4 figures, 5 tables

Characterization of sediment in a leaching trench RCRA (Resource Conservation and Recovery Act) site

International Nuclear Information System (INIS)

Zimmerman, M.G.; Kossik, C.D.

1988-01-01

Hazardous materials potentially were disposed of into a pair of leaching trenches from 1975 until Resource Conservation and Recovery Act (RCRA) regulations were imposed in 1985. These leaching trenches now are used for disposal of nonhazardous process water. The typical effluent (approximately 3 million gal/d) consisted of water with trace quantities of laboratory, maintenance, and fuel fabrication process chemicals. The largest constituent in the waste stream was uranium in low concentrations. This paper describes the project used to analyze and characterize the sediments in and below the leaching trenches. Two phases of sediment sampling were performed. The first phase consisted of taking samples between the bottom of the trenches and groundwater to locate contamination in the deep sediments under the trenches. To accomplish this sampling, a series of wells were drilled, and samples were obtained for every five feet in depth. The second phase consisted of samples taken at three depths in a series of positions along each trench. Sampling was completed to determine contamination levels in the shallow sediments and loose material washed into the trenches from the process sewer system. The project results were that no measurable contamination was found in the deep sediments. Measurable contamination from metals, such as chromium and nickel, was found in the shallow sediments. The primary contaminant in the shallow sediments was uranium. The concentration of contaminants decreased rapidly to near-background levels at shallow depths below the bottoms of the trenches

Fire hazard analysis of the radioactive mixed waste trenchs

International Nuclear Information System (INIS)

McDonald, K.M.

1995-01-01

This Fire Hazards Analysis (FHA) is intended to assess comprehensively the risk from fire associated with the disposal of low level radioactive mixed waste in trenches within the lined landfills, provided by Project W-025, designated Trench 31 and 34 of the Burial Ground 218-W-5. Elements within the FHA make recommendations for minimizing risk to workers, the public, and the environment from fire during the course of the operation's activity. Transient flammables and combustibles present that support the operation's activity are considered and included in the analysis. The graded FHA contains the following elements: description of construction, protection of essential safety class equipment, fire protection features, description of fire hazards, life safety considerations, critical process equipment, high value property, damage potential--maximum credible fire loss (MCFL) and maximum possible fire loss (MPFL), fire department/brigade response, recovery potential, potential for a toxic, biological and/or radiation incident due to a fire, emergency planning, security considerations related to fire protection, natural hazards (earthquake, flood, wind) impact on fire safety, and exposure fire potential, including the potential for fire spread between fire areas. Recommendations for limiting risk are made in the text of this report and printed in bold type. All recommendations are repeated in a list in Section 18.0

Heterogeneous distribution of pelagic sediments incoming the Japan Trench possibly controlling slip propagation on shallow plate boundary fault

Science.gov (United States)

Yamaguchi, A.; Nakamura, Y.; Fukuchi, R.; Kurano, H.; Ikehara, K.; Kanamatsu, T.; Arai, K.; Usami, K.; Ashi, J.

2017-12-01

Catastrophic tsunami of the 2011 Tohoku Earthquake was triggered by large coseismic slip reached to the Japan Trench axis (e.g. Fujiwara et al., 2011, Science; Kodaira et al., 2012, Nature Geoscience). Results of the IODP Expedition 343 (JFAST) suggest that small friction of smectite-rich pelagic clay caused slip propagation on shallow plate boundary fault (Ujiie et al., 2013, Science; Kameda et al., 2015, Geology; Moore et al., 2015, Geosphere). On the other hand, JAMSTEC high-resolution seismic profiles show that incoming sediments have large heterogeneities in thicknesses, and two areas of extremely thin sediments on the Pacific Plate (thickness less than 100 m) were found at around 39°N (Nakamura et al., AGU 2017, this session). To reconcile whether the smectite-rich pelagic clay even exists in these areas, we sampled surface sediments during the R/V Shinsei Maru KS-15-3 cruise. Seven piston cores were retrieved from seaward trench slope, horst, graben, and graben edge. Core lithologies are mainly diatomaceous ooze/clay including tephra layers, not resemble to pelagic clays discovered in JFAST. Ages of tephra layers were estimated by correlating mineral assemblages and refractive indices of volcanic glasses to Japanese widespread tephras. Averaged sedimentation rates of seaward trench slope, horst, graben, and graben edge are estimated to be 25-30, 6.5-20, 45, 0.9 cm/kyr, respectively. These sedimentation rates imply that sediments on seaward trench slope and horst have been deposited in the last 160-500 kyr, suggesting that entire pelagic sediments, including smectite-rich pelagic clay, have been removed by some reasons in the last 0.5 million years. Possible reason for such modification of sediment is near-trench igneous activity known as petit-spot volcanism (Hirano et al., 2006, Science). The lack of smectite-rich pelagic clay near 39°N of the Japan Trench is consistent with results of tsunami inversions proposing shallow large coseismic slip propagated

INTRAVAL Phase 2: Modeling testing at the Las Cruces Trench Site

International Nuclear Information System (INIS)

Hills, R.G.; Rockhold, M.; Xiang, J.; Scanlon, B.; Wittmeyer, G.

1994-01-01

Several field experiments have been performed by scientists from the University of Arizona and New Mexico State University at the Las Cruces Trench Site to provide data tc test deterministic and stochastic models for water flow and solute transport. These experiments were performed in collaboration with INTRAVAL, an international effort toward validation of geosphere models for the transport of radionuclides. During Phase I of INTRAVAL, qualitative comparisons between experimental data and model predictions were made using contour plots of water contents and solute concentrations. Detailed quantitative comparisons were not made. To provide data for more rigorous model testing, a third Las Cruces Trench experiment was designed by scientists from the University of Arizona and New Mexico State University. Modelers from the Center for Nuclear Waste Regulatory Analysis, Massachusetts Institute of Technology, New Mexico State University, Pacific Northwest Laboratory, and the University of Texas provided predictions of water flow and tritium transport to New Mexico State University for analysis. The corresponding models assumed soil characterizations ranging from uniform to deterministically heterogeneous to stochastic. This report presents detailed quantitative comparisons to field data

Hydrologic behaviour of stormwater infiltration trenches in a central urban area during 2 3/4 years of operation

DEFF Research Database (Denmark)

Warnaars, E.; Larsen, A.V.; Jacobsen, P.

1999-01-01

overflow. Analyses of falling water tables after rain indicated slight clogging, but this effect is less important than the general lack of knowledge about soil permeability for normal design situations. The results indicate that the stormwater infiltration in central urban areas with compressed soils...... an initial soil survey. Although the two trenches are placed close to each other they function rather differently, corresponding to effective soil permeabilities of 2.10(-6) m/s in one trench and a factor 10 smaller in the other. During 23/4 years of measuring 89 events were recorded, of which 7 caused...

EARTHSAWtm IN-SITU CONTAINMENT OF PITS AND TRENCHES

Energy Technology Data Exchange (ETDEWEB)

Ernest E. Carter, P.E.

2002-09-20

EarthSaw{trademark} is a proposed technology for construction of uniform high quality barriers under and around pits and trenches containing buried radioactive waste without excavating or disturbing the waste. The method works by digging a deep vertical trench around the perimeter of a site, filling that trench with high specific gravity grout sealant, and then cutting a horizontal bottom pathway at the base of the trench with a simple cable saw mechanism. The severed block of earth becomes buoyant in the grout and floats on a thick layer of grout, which then cures into an impermeable barrier. The ''Interim Report on task 1 and 2'' which is incorporated into this report as appendix A, provided theoretical derivations, field validation of formulas, a detailed quantitative engineering description of the technique, engineering drawings of the hardware, and a computer model of how the process would perform in a wide variety of soil conditions common to DOE waste burial sites. The accomplishments of task 1 and 2 are also summarized herein Task 3 work product provides a comprehensive field test plan in Appendix B and a health and safety plan in Appendix C and proposal for a field-scale demonstration of the EarthSaw barrier technology. The final report on the subcontracted stress analysis is provided in Appendix D. A copy of the unified computer model is provided as individual non-functional images of each sheet of the spreadsheet and separately as a Microsoft Excel 2000 file.

A low on-resistance SOI LDMOS using a trench gate and a recessed drain

International Nuclear Information System (INIS)

Ge Rui; Luo Xiaorong; Jiang Yongheng; Zhou Kun; Wang Pei; Wang Qi; Wang Yuangang; Zhang Bo; Li Zhaoji

2012-01-01

An integrable silicon-on-insulator (SOI) power lateral MOSFET with a trench gate and a recessed drain (TGRD MOSFET) is proposed to reduce the on-resistance. Both of the trench gate extended to the buried oxide (BOX) and the recessed drain reduce the specific on-resistance (R on,sp ) by widening the vertical conduction area and shortening the extra current path. The trench gate is extended as a field plate improves the electric field distribution. Breakdown voltage (BV) of 97 V and R on,sp of 0.985 mΩ·cm 2 (V GS = 5 V) are obtained for a TGRD MOSFET with 6.5 μm half-cell pitch. Compared with the trench gate SOI MOSFET (TG MOSFET) and the conventional MOSFET, R on,sp of the TGRD MOSFET decreases by 46% and 83% at the same BV, respectively. Compared with the SOI MOSFET with a trench gate and a trench drain (TGTD MOSFET), BV of the TGRD MOSFET increases by 37% at the same R on,sp . (semiconductor devices)

A Generic Water Balance Model for a Trench Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Choi, Hee Joo

2016-01-01

To quantify the exposure dose rates from the nuclide release and transport through the various pathways possible in the near- and far-fields of the LILW repository system, various scenarios are to be conveniently simulated in a straightforward manner and extensively with this GoldSim model, as similarly developed for other various types of repositories in previous studies. Through this study, a result from four scenario cases, each of which is or is not associated with water balance, are compared to each other to see what happens in different cases in which an overflow over a trench rooftop, stochastic rainfall on the trench cover, and an unsaturated flow scheme under the trench bottom are combined. The other two latter elements vary periodically owing to stochastic behavior of the time series data for the past rain-fall records. This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various scenarios that can occur after a failure of waste packages with associated uncertainty. An illustration conducted through a study with a new water balance scheme shows the possibility of a stochastic evaluation associated with the stochastic behavior and various pathways that happen around the trench repository.

A Generic Water Balance Model for a Trench Repository

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Myoung; Choi, Hee Joo [KAERI, Daejeon (Korea, Republic of)

2016-05-15

To quantify the exposure dose rates from the nuclide release and transport through the various pathways possible in the near- and far-fields of the LILW repository system, various scenarios are to be conveniently simulated in a straightforward manner and extensively with this GoldSim model, as similarly developed for other various types of repositories in previous studies. Through this study, a result from four scenario cases, each of which is or is not associated with water balance, are compared to each other to see what happens in different cases in which an overflow over a trench rooftop, stochastic rainfall on the trench cover, and an unsaturated flow scheme under the trench bottom are combined. The other two latter elements vary periodically owing to stochastic behavior of the time series data for the past rain-fall records. This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various scenarios that can occur after a failure of waste packages with associated uncertainty. An illustration conducted through a study with a new water balance scheme shows the possibility of a stochastic evaluation associated with the stochastic behavior and various pathways that happen around the trench repository.

Study of shallow trench isolation technology with a poly-Si sidewall buffer layer

International Nuclear Information System (INIS)

Juang, M H; Chen, C L; Jang, S L

2008-01-01

Shallow trench isolation (STI) technology with a poly-Si buffer layer at the trench sidewall has been studied. At the densification temperature of 950 °C, for the samples without using a poly-Si buffer layer, the resulting junction shows a leakage of about 700 nA cm −2 for a diode area of 100 × 100 µm 2 , primarily due to large peripheral junction leakage. The large leakage is ascribed to the defect generation caused by a thermally induced stress near the trench sidewall. The usage of a poly-Si buffer layer in the trench sidewall is found to significantly improve the junction characteristics. As a result, when a 40 nm poly-Si buffer layer is sandwiched between the Si substrate and the trench-fill silicon oxide, the resultant junctions show a leakage of only about 8 nA cm −2 . This result may reflect the considerably reduced thermally induced stress near the trench sidewall. Furthermore, at the densification temperature of 1100 °C, the usage of a poly-Si buffer layer can help to achieve excellent junctions with a leakage smaller than 5 nA cm −2 for a diode area of 100 × 100 µm 2

ORNL Solid Waste Storage Area 6 trench photos and geologic descriptions, July 1984-September 1985

International Nuclear Information System (INIS)

Davis, E.C.; Marshall, D.S.; Stansfield, R.G.; Dreier, R.B.

1986-03-01

The Environmental Sciences Division of the Oak Ridge National Laboratory has initiated a photographic and descriptive geologic study of low-level waste trenches opened in Solid Waste Storage Area 6 (SWSA-6). From July 1984 through September 1985, trenches were excavated, geologically described, and photographed before being filled and closed. Only three trenches (Nos. 438, 448, and 465) were excavated and closed before photography could be scheduled. It is recommended that the systematic trench characterization procedure outlined in this report be continued under the direction of ORNL's Operations Division with support from both Environmental Sciences and the Engineering divisions. Publication of such a compilation of trench photos on a yearly basis will serve not only as a part of Department of Energy trench documentation requirements but also as a component of a SWSA-6 geologic data base being developed for current research and development activities. 2 refs., 38 figs

In situ grouting of low-level burial trenches with a cement-based grout at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Francis, C.W.; Spence, R.D.; Tamura, T.; Spalding, B.P.

1993-01-01

A technology being evaluated for use in the closure of one of the low-level radwaste burial grounds at ORNL is trench stabilization using a cement-based grout. To demonstrate the applicability and effectiveness of this technology, two interconnecting trenches in SWSA 6 were selected as candidates for in situ grouting with a particulate grout. The primary objective was to demonstrate the increased trench stability (characterized by trench penetration tests) and the decreased potential for leachate migration (characterized by hydraulic conductivity tests) following in situ injection of a particulate grout into the waste trenches. Stability against trench subsidence is a critical issue. For example, construction of impermeable covers to seal the trenches will be ineffectual unless subsequent trench subsidence is permanently suspended. A grout composed of 39% Type 1 Portland cement, 55.5% Class F fly ash, and 5.5% bentonite mixed at 12.5 lb/gal of water was selected. Before the trenches were grouted, the primary characteristics relating to physical stability, hydraulic conductivity, and void volume of the trenches were determined. Their physical stability was evaluated using soil-penetration tests

Evaluation of 1985--1986 corrective actions at ORNL liquid waste disposal trench 7

International Nuclear Information System (INIS)

Spalding, B.P.

1991-04-01

Several corrective actions were taken in 1985--1986 at the site of ORNL radioactive liquid waste seepage trench 7 in an effort to reduce the discharge of radionuclides, mostly 60 Co, from a groundwater seep on the eastern side of the site. First, the size of the asphalt cap over the trench was doubled, and cap runoff was diverted away from the site to the west. Second, the buried waste transfer line to the trench was excavated and plugged and its pipe trench was damned with clay backfill. These actions were designed to reduce groundwater recharge in the area that might be the source of water to the seep. Third, a series of grout injections was carried out at 5-ft intervals along a perimeter line on the eastern and northern edges of the site. A total of 65,500 gal of lime-fly-ash grout was injected at 303 locations at depths up to 40 ft in an effort to seal relict contaminated strata with probable hydrologic connection to the seep. However, the grout formulation specified in the contract would not set to a detectable compressive strength nor would the grout samples exhibit a reduction in hydraulic conductivity during over a year of observation. Thus, the material specification for the grout was inappropriate for the desired effect of in situ hydrologic isolation. Core sampling at the site revealed that the grout flowed into the soil formation along discrete thin layers. Only three grout layers, with a maximum thickness of 0.25 in., were found in over 90 ft of core from three locations along the grout injection line. Thus, this grouting action would have little potential to influence containment of radionuclides that leach from contaminated strata. 11 refs., 14 figs., 7 tabs

Retrieval of buried depleted uranium from the T-1 trench

International Nuclear Information System (INIS)

Burmeister, M.; Castaneda, N.; Hull, C.; Barbour, D.; Quapp, W.J.

1998-01-01

The Trench 1 remediation project will be conducted this year to retrieve depleted uranium and other associated materials from a trench at Rocky Flats Environmental Technology Site. The excavated materials will be segregated and stabilized for shipment. The depleted uranium will be treated at an offsite facility which utilizes a novel approach for waste minimization and disposal through utilization of a combination of uranium recycling and volume efficient uranium stabilization

Atomic force microscopy deep trench and sidewall imaging with an optical fiber probe

Energy Technology Data Exchange (ETDEWEB)

Xie, Hui, E-mail: xiehui@hit.edu.cn; Hussain, Danish; Yang, Feng [The State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, 150080 Harbin (China); Sun, Lining [The State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, 150080 Harbin (China); Robotics and Microsystems Center, Soochow University, 215021 Suzhou (China)

2014-12-15

We report a method to measure critical dimensions of micro- and nanostructures using the atomic force microscope (AFM) with an optical fiber probe (OFP). This method is capable of scanning narrow and deep trenches due to the long and thin OFP tip, as well as imaging of steep sidewalls with unique profiling possibilities by laterally tilting the OFP without any modifications of the optical lever. A switch control scheme is developed to measure the sidewall angle by flexibly transferring feedback control between the Z- and Y-axis, for a serial scan of the horizontal surface (raster scan on XY-plane) and sidewall (raster scan on the YZ-plane), respectively. In experiments, a deep trench with tapered walls (243.5 μm deep) and a microhole (about 14.9 μm deep) have been imaged with the orthogonally aligned OFP, as well as a silicon sidewall (fabricated by deep reactive ion etching) has been characterized with the tilted OFP. Moreover, the sidewall angle of TGZ3 (AFM calibration grating) was accurately measured using the switchable scan method.

Evaluation of proposed shallow-land burial sites using the PRESTO-II [Prediction of Radiation Effects from Shallow Trench Operations] methodology and code

International Nuclear Information System (INIS)

Fields, D.E.; Uslu, I.; Yalcintas, M.G.

1987-01-01

PRESTO-II (Prediction of Radiation Effects from Shallow Trench Operations) is a computer code designed to evaluate possible doses and risks (health effects) from shallow-land burial sites. The model is intended to serve as a non-site-specific screening model for assessing radionuclide transport, ensuing exposure, and health impacts to a static local population for a 1000-year period following the end of disposal operations. Human exposure scenarios include normal releases (including leaching and operational spillage), human intrusion, and limited site farming or reclamation. Pathways and processes of transport from the trench to an individual or population include ground-water transport, overland flow, erosion, surface water dilution, suspension, atmospheric transport and deposition, inhalation, external exposure, and ingestion of contaminated beef, milk, crops, and water. The proposed waste disposal area in Koteyli, Balikesir, Turkey, has been evaluated using the PRESTO-II methodology. The results have been compared to those obtained for the Barnwell, South Carolina, site. Dose estimates for both sites are below regulatory limits, for the release and exposure scenarios considered. The doses for the sites are comparable, with slightly higher estimates obtained for the Turkish site. 7 refs., 1 tab

Trench foot: the medical response in the first World War 1914-18.

Science.gov (United States)

Atenstaedt, Robert L

2006-01-01

The approaching 90-year anniversary of United States entry into the Great War is an apt time to examine the response to trench foot (now called nonfreezing cold injury [NFCI]) in this conflict. Trench foot appeared in the winter of 1914, characterized by pedal swelling, numbness, and pain. It was quickly recognized by military-medical authorities. There was little debate over whether it was frostbite or new condition, and it was quickly accepted as a specific disease. The major etiologies proposed were exposure, diet, and infection. The opinion emerged that it was caused by circulatory changes in the foot caused by cold, wet, and pressure. Predisposing factors included dietary inadequacy and fatigue. A number of labels were first given to the disease. However, the name "trench foot" was eventually officially sanctioned. Trench foot became a serious problem for the Allies, leading to 75 000 casualties in the British and 2000 in the American forces. Therapy for trench foot involved a number of conventional, tried-and-tested, and conservative methods. Some more innovative techniques were used. Amputation was only used as a last resort. Prevention involved general measures to improve the trench environment; modification of the footwear worn by the men; and the provision of greases to protect them from moisture. The medical reaction to this condition seems to have been relatively effective. The causation was identified, and prophylactic measures were introduced to fit this model; these seem to have been successful in reducing the prevalence of the condition by 1917-18.

40 CFR 265 interim status indicator-evaluation ground-water monitoring plan for the 216-B-63 trench

International Nuclear Information System (INIS)

Bjornstad, B.N.; Dudziak, S.

1989-03-01

This document outlines a ground-water monitoring plan for the 216-B-63 trench located in the northeast corner of the 200-East Area on the Hanford Site in southeastern Washington State. It has been determined that hazardous materials (corrosives) were disposed of to the trench during past operations. Installation of an interim-status ground-water monitoring system is required to determine whether hazardous chemicals are leaching to the ground water from beneath the trench. This document summarizes the existing data that are available from near the 216-B-63 trench and presents a plan to determine the extent of ground-water contamination, if any, derived from the trench. The plan calls for the installation of four new monitoring wells located near the west end of the trench. These wells will be used to monitor ground-water levels and water quality immediately adjacent to the trench. Two existing RCRA monitoring wells, which are located near the trench and hydraulically upgradient of it, will be used as background wells. 46 refs., 15 figs., 12 tabs

Simulation of new p-type strip detectors with trench to enhance the charge multiplication effect in the n-type electrodes

International Nuclear Information System (INIS)

Fernández-Martínez, P.; Pellegrini, G.; Balbuena, J.P.; Quirion, D.; Hidalgo, S.; Flores, D.; Lozano, M.; Casse, G.

2011-01-01

This paper shows the simulation results of new p-type strip detectors with trench electrodes to enhance the charge multiplication effect in the irradiated detector. The new design includes baby microstrip detectors (area=1 cm 2 ) with a strip pitch of 80 μm and p-stop isolation structures. The strip has a 5 μm-wide trench along all its length, filled and doped with polysilicon to create a deep N + contact into the material bulk. The trench depth can be varied in order to study the influence of the electric field on the charge multiplication effect in heavily irradiated samples. Some alternative designs have also been studied to establish a comparison between various structures using different technologies. Simulation reproduce the electrical behaviour under different irradiation conditions, taking into account the damage accumulated after irradiation with neutrons and protons with several fluence values. The investigation of these effects provides important indications on the ability of this modified electrode geometry to control and optimise the charge multiplication effect, in order to fully recover the collection efficiency of heavily irradiated microstrip detectors, at reasonable bias voltage compatible with the voltage feed limitation of the CERN SLHC experiments.

A case of bilateral trench foot.

Science.gov (United States)

Parsons, S L; Leach, I H; Charnley, R M

1993-12-01

A case of severe bilateral trench foot is presented in a patient who lived rough for 3 weeks without removing his boots. Non-operative management yielded no clinical improvement and bilateral below-knee amputation was necessary. Histology revealed subcutaneous and muscle necrosis with secondary arterial thrombosis.

Chemical characteristics of hadal waters in the Izu-Ogasawara Trench of the western Pacific Ocean.

Science.gov (United States)

Gamo, Toshitaka; Shitashima, Kiminori

2018-01-01

Vertical profiles of potential temperature, salinity, and some chemical components were obtained at a trench station (29°05'N, 142°51'E; depth = 9768 m) in the Izu-Ogasawara (Bonin) Trench in 1984 and 1994 to characterize the hadal waters below ∼6000 m depth. We compared portions of both the 1984 and 1994 profiles with nearby data obtained between 1976 and 2013. Results demonstrated that the hadal waters had slightly higher potential temperature and nitrate and lower dissolved oxygen than waters at sill depths (∼6000 m) outside the trench, probably due to the effective accumulation of geothermal heat and active biological processes inside the trench. The silicate, iron, and manganese profiles in 1984 showed slight but significant increases below ∼6000 m depth, suggesting that these components may have been intermittently supplied from the trench bottom. Significant amounts of 222 Rn in excess over 226 Ra were detected in the hadal waters up to 2675 m from the bottom, reflecting laterally supplied 222 Rn from the trench walls.

Response of Microbial Community Function to Fluctuating Geochemical Conditions within a Legacy Radioactive Waste Trench Environment.

Science.gov (United States)

Vázquez-Campos, Xabier; Kinsela, Andrew S; Bligh, Mark W; Harrison, Jennifer J; Payne, Timothy E; Waite, T David

2017-09-01

During the 1960s, small quantities of radioactive materials were codisposed with chemical waste at the Little Forest Legacy Site (Sydney, Australia) in 3-meter-deep, unlined trenches. Chemical and microbial analyses, including functional and taxonomic information derived from shotgun metagenomics, were collected across a 6-week period immediately after a prolonged rainfall event to assess the impact of changing water levels upon the microbial ecology and contaminant mobility. Collectively, results demonstrated that oxygen-laden rainwater rapidly altered the redox balance in the trench water, strongly impacting microbial functioning as well as the radiochemistry. Two contaminants of concern, plutonium and americium, were shown to transition from solid-iron-associated species immediately after the initial rainwater pulse to progressively more soluble moieties as reducing conditions were enhanced. Functional metagenomics revealed the potentially important role that the taxonomically diverse microbial community played in this transition. In particular, aerobes dominated in the first day, followed by an increase of facultative anaerobes/denitrifiers at day 4. Toward the mid-end of the sampling period, the functional and taxonomic profiles depicted an anaerobic community distinguished by a higher representation of dissimilatory sulfate reduction and methanogenesis pathways. Our results have important implications to similar near-surface environmental systems in which redox cycling occurs. IMPORTANCE The role of chemical and microbiological factors in mediating the biogeochemistry of groundwaters from trenches used to dispose of radioactive materials during the 1960s is examined in this study. Specifically, chemical and microbial analyses, including functional and taxonomic information derived from shotgun metagenomics, were collected across a 6-week period immediately after a prolonged rainfall event to assess how changing water levels influence microbial ecology and

Paleoseismological data from a new trench across the El Camp Fault(Catalan Coastal Ranges, NE Iberian Peninsula

Directory of Open Access Journals (Sweden)

K. Boydell

2003-06-01

Full Text Available The El Camp Fault (Catalan Coastal Ranges, NE Iberian Peninsula is a slow slipping normal fault whose seismic potential has only recently been recognised. New geomorphic and trench investigations were carried out during a training course across the El Camp Fault at the La Porquerola alluvial fan site. A new trench (trench 8 was dug close to a trench made previously at this site (trench 4. With the aid of two long topographic profiles across the fault scarp we obtained a vertical slip rate ranging between 0.05 and 0.08 mm/yr. At the trench site, two main faults, which can be correlated between trenches 8 and 4, make up the fault zone. Using trench analysis three paleoseismic events were identified, two between 34.000 and 125.000 years BP (events 3 and 2 and another event younger than 13 500 years BP (event 1, which can be correlated, respectively, with events X (50.000- 125.000 years BP, Y (35.000-50.000 years BP and Z (3000-25.000 years BP. The last seismic event at the La Porquerola alluvial fan site is described for the first time, but with some uncertainties.

Characterization of trench water at the Maxey Flats low-level radioactive waste disposal site

International Nuclear Information System (INIS)

Weiss, A.J.; Francis, A.J.; Colombo, P.

1977-01-01

Currently the United States Geological Survey is conducting a study of the hydrogeological and geochemical behavior of commercially operated low-level radioactive waste disposal sites. The data collected from this study will be used to establish criteria for selection of new sites for disposal of radioactive wastes. As part of this study, water samples from trenches at the Maxey Flats, Kentucky site were analyzed at Brookhaven National Laboratory to determine the source terms of the radionuclides and other components in solution in the trenches. Procedures for collection and filtration of the samples under anoxic conditions are described. The samples were analyzed for inorganic, radiochemical and organic constituents. The inorganic analysis includes the measurements of pH, specific conductance, alkalinity, and various cations and anions. The radionuclides were measured by the gross alpha, gross beta, tritium, and gamma activities, followed by specific measurements of strontium-90 and plutonium isotopes. The organics were extracted, concentrated, and identified by gas chromatography/mass spectrometry. Considerable quantities of organics were detected in all of the trench waters sampled. Specific organics were found in most of the trenches, however, the organic composition of the trench waters vary. The presence of a variety of organic compounds in trench waters suggest that they may play an important role in the transport of radionuclides

The Micro Trench Gas Counter

International Nuclear Information System (INIS)

Schmitz, J.

1991-07-01

A novel design is presented for a gas avalanche chamber with micro-strip gas readout. While existing gaseous microstrip detectors (Micro-strip Gas Counters, Knife edge chambers) have a minimum anode pitch of the order of 100 μm, the pitch of the discussed Micro Trench Gas Counter goes down to 30-50 μm. This leads to a better position resolution and two track separation, and a higher radiation resistivity. Its efficiency and signal speed are expected to be the same as the Microstrip Gas Counter. The energy resolution of the device is expected to be equal to or better than 10 percent for the 55 Fe peak. Since the anode strip dimensions are larger than those in a MSGC, the device may be not as sensitive to discharges and mechanical damage. In this report production of the device is briefly described, and predictions on its operation are made based on electric field calculations and experience with the Microstrip Gas Counter. The authors restrict themselves to the application in High Energy Physics. (author). 10 refs.; 9 figs

Rock magnetic and geochemical analyses of surface sediment characteristics in deep ocean environments: A case study across the Ryukyu Trench

Science.gov (United States)

Kawamura, N.; Kawamura, K.; Ishikawa, N.

2008-03-01

Magnetic minerals in marine sediments are often dissolved or formed with burial depth, thereby masking the primary natural remanent magnetization and paleoclimate signals. In order to clarify the present sedimentary environment and the progressive changes with burial depth in the magnetic properties, we studied seven cores collected from the Ryukyu Trench, southwest Japan. Magnetic properties, organic geochemistry, and interstitial water chemistry of seven cores are described. Bottom water conditions at the landward slope, trench floor, and seaward slope are relatively suboxic, anoxic, and oxic, respectively. The grain size of the sediments become gradually finer with the distance from Okinawa Island and finer with increasing water depth. The magnetic carriers in the sediments are predominantly magnetite and maghemized magnetite, with minor amounts of hematite. In the topmost sediments from the landward slope, magnetic minerals are diluted by terrigenous materials and microfossils. The downcore variations in magnetic properties and geochemical data provided evidence for the dissolution of fine-grained magnetite with burial depth under an anoxic condition.

High aspect ratio titanium nitride trench structures as plasmonic biosensor

DEFF Research Database (Denmark)

Shkondin, Evgeniy; Repän, Taavi; Takayama, Osamu

2017-01-01

High aspect ratio titanium nitride (TiN) grating structures are fabricated by the combination of deep reactive ion etching (DRIE) and atomic layer deposition (ALD) techniques. TiN is deposited at 500 ◦C on a silicon trench template. Silicon between vertical TiN layers is selectively etched...... to fabricate the high aspect ratio TiN trenches with the pitch of 400 nm and height of around 2.7 µm. Dielectric functions of TiN films with different thicknesses of 18 - 105 nm and post-annealing temperatures of 700 - 900 ◦C are characterized by an ellipsometer. We found that the highest annealing temperature...... of 900 ◦C gives the most pronounced plasmonic behavior with the highest plasma frequency, ωp = 2.53 eV (λp = 490 nm). Such high aspect ratio trench structures function as a plasmonic grating sensor that supports the Rayleigh-Woods anomalies (RWAs), enabling the measurement of changes in the refractive...

Partial liquid-penetration inside a deep trench by film flowing over it

Science.gov (United States)

Nguyen, Phuc-Khanh; Dimakopoulos, Yiannis; Tsamopoulos, John

2014-11-01

Liquid film flow along substrates featuring a deep trench may not wet the trench floor, but create a second gas-liquid interface inside the trench. The liquid penetration inside the trench depends on the location and shape of this inner interface. The penetration increases by decreasing the two three-phase contact lines between the inner interface and the two side-walls or the flow rate and depends on the liquid properties. This partial-penetration is studied by employing the Galerkin / finite element method to solve the two-dimensional steady-state Navier-Stokes equations in a physical domain that is adaptively remeshed. Multiple branches of steady solutions connected via turning points are revealed by pseudo arc-length continuation. Flow hysteresis may occur in a certain range of liquid penetration depth, when the interaction of the two interfaces changes qualitatively. This induces an abrupt jump of penetration distance and deformation amplitude of the outer interface. Work supported by the General Secretariat of Research & Technology of Greece through the program ``Excellence'' (Grant No. 1918) in the framework ``Education and Lifelong Learning'' co-funded by the ESF.

Review of corrective measures to stabilize subsidence in shallow-land burial trenches

International Nuclear Information System (INIS)

Roop, R.D.; Staub, W.P.; Hunsaker, D.B. Jr.; Ketelle, R.H.; Lee, D.W.; Pin, F.G.; Witten, A.J.

1983-05-01

Shallow-land burial of low-level radioactive wastes is frequently followed by subsidence: the slumping, cave-in, or depression of the trench's surface. This report describes and evaluates the measures proposed for correcting subsidence, including roller compaction, grouting, explosives, surcharging, falling mass, pile driving, in situ incineration, and accelerated decomposition. Subsidence, which has occurred at all the major waste disposal sites, has two major causes: filling of packing voids (spaces between waste containers) and filling of interior voids (spaces within containers). Four additional mechanisms also contribute to subsidence: collapse of trench walls, chemical and biological degradation, soil consolidation, and shrink and swell phenomena. Corrective measures for subsidence are evaluated on three criteria: effectiveness, applicability, and cost. The evaluation indicates that one method, falling mass, is considered to be effective, widely applicable, and relatively low in cost, suggesting that this would be the most generally useful technique and would yield the greatest payoff from further development and field trials. There are many uncertainties associated with the cost and effectiveness of corrective measures which can best be resolved by experimental field demonstrations. Site-specific analyses for each disposal area are recommended, to determine which techniques are appropriate and to evaluate the overall desirability of applying corrective measures

The GaN trench gate MOSFET with floating islands: High breakdown voltage and improved BFOM

Science.gov (United States)

Shen, Lingyan; Müller, Stephan; Cheng, Xinhong; Zhang, Dongliang; Zheng, Li; Xu, Dawei; Yu, Yuehui; Meissner, Elke; Erlbacher, Tobias

2018-02-01

A novel GaN trench gate (TG) MOSFET with P-type floating islands (FLI) in drift region, which can suppress the electric field peak at bottom of gate trench during the blocking state and prevent premature breakdown in gate oxide, is proposed and investigated by TCAD simulations. The influence of thickness, position, doping concentration and length of the FLI on breakdown voltage (BV) and specific on-resistance (Ron_sp) is studied, providing useful guidelines for design of this new type of device. Using optimized parameters for the FLI, GaN FLI TG-MOSFET obtains a BV as high as 2464 V with a Ron_sp of 3.0 mΩ cm2. Compared to the conventional GaN TG-MOSFET with the same structure parameters, the Baliga figure of merit (BFOM) is enhanced by 150%, getting closer to theoretical limit for GaN devices.

Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

Science.gov (United States)

Schmidt, Christina; Martínez Arbizu, Pedro

2015-01-01

We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

Cleanup Verification Package for the 116-K-2 Effluent Trench

International Nuclear Information System (INIS)

Capron, J.M.

2006-01-01

This cleanup verification package documents completion of remedial action for the 116-K-2 effluent trench, also referred to as the 116-K-2 mile-long trench and the 116-K-2 site. During its period of operation, the 116-K-2 site was used to dispose of cooling water effluent from the 105-KE and 105-KW Reactors by percolation into the soil. This site also received mixed liquid wastes from the 105-KW and 105-KE fuel storage basins, reactor floor drains, and miscellaneous decontamination activities

Benchmarking Exercises To Validate The Updated ELLWF GoldSim Slit Trench Model

International Nuclear Information System (INIS)

Taylor, G. A.; Hiergesell, R. A.

2013-01-01

The Savannah River National Laboratory (SRNL) results of the 2008 Performance Assessment (PA) (WSRC, 2008) sensitivity/uncertainty analyses conducted for the trenches located in the EArea LowLevel Waste Facility (ELLWF) were subject to review by the United States Department of Energy (U.S. DOE) Low-Level Waste Disposal Facility Federal Review Group (LFRG) (LFRG, 2008). LFRG comments were generally approving of the use of probabilistic modeling in GoldSim to support the quantitative sensitivity analysis. A recommendation was made, however, that the probabilistic models be revised and updated to bolster their defensibility. SRS committed to addressing those comments and, in response, contracted with Neptune and Company to rewrite the three GoldSim models. The initial portion of this work, development of Slit Trench (ST), Engineered Trench (ET) and Components-in-Grout (CIG) trench GoldSim models, has been completed. The work described in this report utilizes these revised models to test and evaluate the results against the 2008 PORFLOW model results. This was accomplished by first performing a rigorous code-to-code comparison of the PORFLOW and GoldSim codes and then performing a deterministic comparison of the two-dimensional (2D) unsaturated zone and three-dimensional (3D) saturated zone PORFLOW Slit Trench models against results from the one-dimensional (1D) GoldSim Slit Trench model. The results of the code-to-code comparison indicate that when the mechanisms of radioactive decay, partitioning of contaminants between solid and fluid, implementation of specific boundary conditions and the imposition of solubility controls were all tested using identical flow fields, that GoldSim and PORFLOW produce nearly identical results. It is also noted that GoldSim has an advantage over PORFLOW in that it simulates all radionuclides simultaneously - thus avoiding a potential problem as demonstrated in the Case Study (see Section 2.6). Hence, it was concluded that the follow

Benchmarking Exercises To Validate The Updated ELLWF GoldSim Slit Trench Model

Energy Technology Data Exchange (ETDEWEB)

Taylor, G. A.; Hiergesell, R. A.

2013-11-12

The Savannah River National Laboratory (SRNL) results of the 2008 Performance Assessment (PA) (WSRC, 2008) sensitivity/uncertainty analyses conducted for the trenches located in the EArea LowLevel Waste Facility (ELLWF) were subject to review by the United States Department of Energy (U.S. DOE) Low-Level Waste Disposal Facility Federal Review Group (LFRG) (LFRG, 2008). LFRG comments were generally approving of the use of probabilistic modeling in GoldSim to support the quantitative sensitivity analysis. A recommendation was made, however, that the probabilistic models be revised and updated to bolster their defensibility. SRS committed to addressing those comments and, in response, contracted with Neptune and Company to rewrite the three GoldSim models. The initial portion of this work, development of Slit Trench (ST), Engineered Trench (ET) and Components-in-Grout (CIG) trench GoldSim models, has been completed. The work described in this report utilizes these revised models to test and evaluate the results against the 2008 PORFLOW model results. This was accomplished by first performing a rigorous code-to-code comparison of the PORFLOW and GoldSim codes and then performing a deterministic comparison of the two-dimensional (2D) unsaturated zone and three-dimensional (3D) saturated zone PORFLOW Slit Trench models against results from the one-dimensional (1D) GoldSim Slit Trench model. The results of the code-to-code comparison indicate that when the mechanisms of radioactive decay, partitioning of contaminants between solid and fluid, implementation of specific boundary conditions and the imposition of solubility controls were all tested using identical flow fields, that GoldSim and PORFLOW produce nearly identical results. It is also noted that GoldSim has an advantage over PORFLOW in that it simulates all radionuclides simultaneously - thus avoiding a potential problem as demonstrated in the Case Study (see Section 2.6). Hence, it was concluded that the follow

Hadal disturbance in the Japan Trench induced by the 2011 Tohoku-Oki earthquake

DEFF Research Database (Denmark)

Oguri, K.; Kawamura, K.; Sakaguchi, A.

2013-01-01

In situ video observations and sediment core samplings were performed at two hadal sites in the Japan Trench on July, 2011, four months after the Tohoku-Oki earthquake. Video recordings documented dense nepheloid layers extending similar to 30-50 m above the sea bed. At the trench axis, benthic...

Control of water infiltration through SLB trench covers

International Nuclear Information System (INIS)

Schulz, R.K.; Ridky, R.W.

1986-01-01

A technique for control of water infiltration into waste burial trenches is described. Initial results show the procedure to be very promising. In essence, the technique combines engineered or positive control of run-off, along with a vegetative cover, and is named bioengineering management. To investigate control of infiltration, lysimeters are being used to make complete water balance measurements. The studies are underway at the Maxey Flats, Kentucky, low-level waste burial site. Where the original Maxey Flats site closure procedure is followed, it is necessary to pump large amounts of water out of the lysimeters to prevent the water table from rising closer than 2 meters from the surface. Using the fescue grass bioengineering management procedure, no pumping is required. Encouraged by the initial findings in the rather small-scale lysimeters, a large scale demonstration of the bioengineering management technique has been initiated in Beltsville, Maryland. 6 references, 14 figures

Simple analytical expression for crosstalk estimation in homogeneous trench-assisted multi-core fibers

DEFF Research Database (Denmark)

Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

2014-01-01

An analytical expression for the mode coupling coe cient in homogeneous trench-assisted multi-core fibers is derived, which has a sim- ple relationship with the one in normal step-index structures. The amount of inter-core crosstalk reduction (in dB) with trench-assisted structures compared...... to the one with normal step-index structures can then be written by a simple expression. Comparison with numerical simulations confirms that the obtained analytical expression has very good accuracy for crosstalk estimation. The crosstalk properties in trench-assisted multi-core fibers, such as crosstalk...... dependence on core pitch and wavelength-dependent crosstalk, can be obtained by this simple analytical expression....

Multiple faulting events revealed by trench analysis of the seismogenic structure of the 1976 Ms7.1 Luanxian earthquake, Tangshan Region, China

Science.gov (United States)

Guo, Hui; Jiang, Wali; Xie, Xinsheng

2017-10-01

The Ms7.8 Tangshan earthquake occurred on 28 July 1976 at 03:42 CST. Approximately 15 h later, the Ms7.1 Luanxian earthquake occurred approximately 40 km northeast of the main shock. The two earthquakes formed different surface rupture zones. The surface rupture of the Tangshan earthquake was NNE-trending and more than 47 km long. The surface rupture of the Luanxian earthquake was more than 6 km long and consisted of two sections, forming a protruding arc to the west. The north and south sections were NE- and NW-trending and 2 km and 4 km long, respectively. A trench was excavated in Sanshanyuan Village across the NE-trending rupture of the Luanxian earthquake, at the macroscopic epicenter of the Luanxian earthquake. Analysis of this trench revealed that the surface rupture is connected to the underground active fault. The following major conclusions regarding Late Quaternary fault activity have been reached. (1) The Sanshanyuan trench indicated that its fault planes trend NE30° and dip SE or NW at angles of approximately 69-82°. (2) The fault experienced four faulting events prior to the Luanxian earthquake at 27.98 ka with an average recurrence interval of approximately 7.5 ka. (3) The Ms7.1 Luanxian earthquake resulted from the activity of the Luanxian Western fault and was triggered by the Ms7.8 Tangshan earthquake. The seismogenic faults of the 1976 Ms7.1 Luanxian earthquake and the 1976 Ms7.8 Tangshan earthquake are not the same fault. This example of an M7 earthquake triggered by a nearly M8 earthquake after more than 10 h on a nearby fault is a worthy topic of research for the future prediction of strong earthquakes.

Influence of lateral slab edge distance on plate velocity, trench velocity, and subduction partitioning

NARCIS (Netherlands)

Schellart, W. P.; Stegman, D. R.; Farrington, R. J.; Moresi, L.

2011-01-01

Subduction of oceanic lithosphere occurs through both trenchward subducting plate motion and trench retreat. We investigate how subducting plate velocity, trench velocity and the partitioning of these two velocity components vary for individual subduction zone segments as a function of proximity to

Comparison between infaunal communities of the deep floor and edge of the Tonga Trench

DEFF Research Database (Denmark)

Leduc, Daniel; Rowden, Ashley A.; Glud, Ronnie N.

2016-01-01

at the Horizon Deep site is consistent with a recent turbidite event, and may also reflect high rates of bioturbation by larger fauna resulting from high food availability. Determining the relative influences of different environmental factors on hadal trench benthic communities will require further...... factors. In this study, we describe and compare the abundance, biomass, vertical distribution in the sediment, diversity, and community structure of nematodes and other infauna in sediments from the Horizon Deep (similar to 10 800 m) in the Tonga Trench and a site on the edge of the trench (similar...... to 6250 m). Mean nematode abundance was six times greater at the Horizon Deep site (387 ind. 10 cm(-2)) than at the trench edge site (65 ind. 10 cm(-2)). A similar pattern was observed for biomass (15 vs 2 mu gDW 10 cm(-2), respectively), which likely resulted from elevated organic matter supply...

Microbial activity of trench leachates from shallow-land, low-level radioactive waste disposal sites

International Nuclear Information System (INIS)

Francis, A.J.; Dobbs, S.; Nine, B.J.

1980-01-01

Trench leachate samples collected anoxically from shallow-land, low-level radioactive waste disposal sites were analyzed for total aerobic and anaerobic populations, sulfate reducers, denitrifiers, and methanogens. Among the several aerobic and anaerobic bacteria isolated, only Bacillus sp., Pseudomonas sp., Citrobacter sp., and Clostridium sp. were identified. Mixed bacterial cultures isolated from the trench leachates were able to grow anaerobically in trench leachates, which indicates that the radionuclides and organic chemicals present were not toxic to these bacteria. Changes in concentrations of several of the organic constituents of the waste leachate samples were observed due to anaerobic microbial activity. Growth of a mixed culture of trench-water bacteria in media containing a mixture of radionuclides, 60 Co, 85 Sr, and 134 137 Cs, was not affected at total activity concentrations of 2.6 x 10 2 and 2.7 x 10 3 pCi/ml

Charge deposition model for investigating SE-microdose effect in trench power MOSFETs

Science.gov (United States)

Xin, Wan; Weisong, Zhou; Daoguang, Liu; Hanliang, Bo; Jun, Xu

2015-05-01

It was demonstrated that heavy ions can induce large current—voltage (I-V) characteristics shift in commercial trench power MOSFETs, named single event microdose effect (SE-microdose effect). A model is presented to describe this effect. This model calculates the charge deposition by a single heavy ion hitting oxide and the subsequent charge transport under an electric field. Holes deposited at the SiO2/Si interface by a Xe ion are calculated by using this model. The calculated results were then used in Sentaurus TCAD software to simulate a trench power MOSFET's I-V curve shift after a Xe ion has hit it. The simulation results are consistent with the related experiment's data. In the end, several factors which affect the SE-microdose effect in trench power MOSFETs are investigated by using this model.

Cleanup Verification Package for the 107-D5 Trench

International Nuclear Information System (INIS)

Corpuz, F.M.; Fancher, J.D.; Blumenkranz, D.B.

1998-03-01

This document presents the results of remedial action objectives performed at the 107-D5 Sludge Trench, located at the 100-DR-1 Operable Unit in the 100 Area of the Hanford Site in southeastern Washington State. The 107-D5 Sludge Trench is also identified in the Hanford Waste Information Data System as Waste Site 100-D-4 (site code). The selected remedial action was (1) excavation of the site to the extent required to meet specified soil cleanup levels, (2) disposal of contaminated excavation materials at the Environmental Restoration and Disposal Facility at the 200 Area of the Hanford Site, and (3) backfilling the site with clean soil to adjacent grade elevations

Seismicity and state of stress near the Japan Trench axis off Miyagi, northeast Japan, after the 2011 Tohoku-Oki earthquake

Science.gov (United States)

Obana, K.; Kodaira, S.; Takahashi, T.; Yamamoto, Y.; Nakamura, Y.; No, T.; Fujie, G.; Hino, R.; Shinohara, M.

2013-12-01

The 2011 Tohoku-Oki earthquake ruptured roughly 200 km wide and 500 km long megathrust along the Japan Trench. The rupture propagated to the trench axis with a maximum slip about 50 m near the trench axis. As a consequence of this large near-trench slip, earthquakes have been activated near the axis of the Japan Trench off Miyagi, northeast Japan. We have conducted ocean bottom seismograph (OBS) experiments in the Japan Trench axis area, surrounding area of the IODP JFAST drilling site, since the occurrence of the 2011 Tohoku-Oki earthquake. Although conventionally used OBS cannot be deployed at seafloor deeper than 6000 m water depth, we used newly developed ultra-deep OBS using ceramic sphere, which can be deployed at a depth of 9000 m, for the observations in the trench axis. The ultra-deep OBS has almost equivalent dimensions and weight with the conventionally used OBS, thus we can handle it in the same manner with the conventionally OBS without any special operation. As a result of a series of the OBS observations, we obtained accurate hypocenter locations and focal mechanisms in both seaward and landward of the trench axis. Earthquakes near the trench axis area were located within the overriding and incoming/subducting plates with very few on the plate interface below the inner trench slope landward of the trench axis. Most of the earthquakes both in the overriding and incoming/subducting plates having normal or strike-slip faulting focal mechanisms with T-axis normal to the trench axis. This indicates that tensional stress is dominant in the trench axis area. However, most seaward part of the seismicity within the overriding plate is characterized by a localized cluster of trench-normal compressional earthquakes, which may relate to spatial variation of the frictional behavior of the shallowest part of the megathrust. On the other hand, trench-normal extensional earthquakes in the incoming/subducting Pacific plate were located at depths shallower than about

Benthic carbon mineralization in hadal trenches: Insights from in situ determination of benthic oxygen consumption

DEFF Research Database (Denmark)

Lou, Mín; Glud, Ronnie N.; Pan, Binbin

2018-01-01

and exhibited relatively high diagenetic activity given the great water depths, that is, the Mariana Trench (2.0 × 102 μmol O2m2 d1, 10,853 m), the Mussau Trench (2.7 ± 0.1 × 102 μmol O2m2 d1, 7,011 m), and the New Britain Trench (6.0 ± 0.1 × 102 μmol O2m2  d1, 8,225 m). Combined with the analyses of total...

Control of paleoshorelines by trench forebulge uplift, Loyalty Islands

Science.gov (United States)

Dickinson, William R.

2013-07-01

Unlike most tropical Pacific islands, which lie along island arcs or hotspot chains, the Loyalty Islands between New Caledonia and Vanuatu owe their existence and morphology to the uplift of pre-existing atolls on the flexural forebulge of the New Hebrides Trench. The configuration and topography of each island is a function of distance from the crest of the uplifted forebulge. Both Maré and Lifou are fully emergent paleoatolls upon which ancient barrier reefs form highstanding annular ridges that enclose interior plateaus representing paleolagoon floors, whereas the partially emergent Ouvea paleoatoll rim flanks a drowned remnant lagoon. Emergent paleoshoreline features exposed by island uplift include paleoreef flats constructed as ancient fringing reefs built to past low tide levels and emergent tidal notches incised at past high tide levels. Present paleoshoreline elevations record uplift rates of the islands since last-interglacial and mid-Holocene highstands in global and regional sea levels, respectively, and paleoreef stratigraphy reflects net Quaternary island emergence. The empirical uplift rates vary in harmony with theoretical uplift rates inferred from the different positions of the islands in transit across the trench forebulge at the trench subduction rate. The Loyalty Islands provide a case study of island environments controlled primarily by neotectonics.

Preliminary results of trench mapping at the site of prospective surface facilities for the potential Yucca Mountain repository, Nevada

International Nuclear Information System (INIS)

Wesling, J.R.; Swan, F.H.; Thomas, A.P.; Angell, M.M.

1993-01-01

Mapping and trenching studies are yielding data needed to evaluate the surface faulting potential within Midway Valley, a half graben bounded by west-dipping normal faults on the northeast margin of Yucca Mountain. These studies document the presence of two north-trending zones of fractures within Quaternary deposits along the west-central part of the Midway Valley half-graben block. The westernmost zone of fractures, located along the eastern base of Exile Hill, overlies a complex zone of bedrock faulting and may be related to an apparent down-on-the-east step in the contact between bedrock and colluvium. Fractures striking ∼N15E extend upwards from this apparent bedrock step through early (?) to middle (?) Pleistocene colluvium. The fractures do not extend into the overlying late Pleistocene colluvium. No vertical or lateral separation of the probably middle to late Pleistocene colluvium across fractures can be detected with a resolution of 5 cm or less in most cases. The Quaternary deposits are much thicker along the eastern zone of fractures and bedrock was not exposed. The presence of continuous thin layers within the alluvial strata demonstrate the absence of any detectable vertical or lateral separation of the middle (?) Pleistocene deposits across the fractures within the eastern zone with a high degree of confidence. The results of the authors studies indicate that faults within the west-central part of the Midway Valley structural block have had little or no displacement since at least the mid Quaternary. Therefore, potential for surface fault rupture in this area is extremely low

A high-performance trench capacitor integrated in a passive integration technology

International Nuclear Information System (INIS)

Geiselbrechtinger, Angelika; Büyüktas, Kevni; Allers, Karl-Heinz; Hartung, Wolfgang

2009-01-01

The requirements for the electrical characteristics of passive on-chip devices become more and more important. The electrical performance of RF circuits is predominantly restricted by the passives. New technologies and new device concepts are necessary to meet the demands. In this work, a trench capacitor developed for RF applications is presented for the first time. This so-called SilCap (silicon capacitor) device features very high capacitance density, extreme low-voltage dependence, excellent temperature stability, good RF performance and a high breakthrough voltage. First, the device function and the technological concept are introduced. The concept is realized without implementing cost-intensive high-k materials. This trench capacitor is integrated in the front end of line of a passive integration technology. The achieved specific capacitance density is compared to a standard planar capacitor. Performance of the SilCap in terms of quality factor and breakthrough voltage is shown. Finally, reliability data of this trench capacitor are presented with special focus on extrinsic and dielectric lifetime

Ripple formation on Si surfaces during plasma etching in Cl2

Science.gov (United States)

Nakazaki, Nobuya; Matsumoto, Haruka; Sonobe, Soma; Hatsuse, Takumi; Tsuda, Hirotaka; Takao, Yoshinori; Eriguchi, Koji; Ono, Kouichi

2018-05-01

Nanoscale surface roughening and ripple formation in response to ion incidence angle has been investigated during inductively coupled plasma etching of Si in Cl2, using sheath control plates to achieve the off-normal ion incidence on blank substrate surfaces. The sheath control plate consisted of an array of inclined trenches, being set into place on the rf-biased electrode, where their widths and depths were chosen in such a way that the sheath edge was pushed out of the trenches. The distortion of potential distributions and the consequent deflection of ion trajectories above and in the trenches were then analyzed based on electrostatic particle-in-cell simulations of the plasma sheath, to evaluate the angular distributions of ion fluxes incident on substrates pasted on sidewalls and/or at the bottom of the trenches. Experiments showed well-defined periodic sawtooth-like ripples with their wave vector oriented parallel to the direction of ion incidence at intermediate off-normal angles, while relatively weak corrugations or ripplelike structures with the wave vector perpendicular to it at high off-normal angles. Possible mechanisms for the formation of surface ripples during plasma etching are discussed with the help of Monte Carlo simulations of plasma-surface interactions and feature profile evolution. The results indicate the possibility of providing an alternative to ion beam sputtering for self-organized formation of ordered surface nanostructures.

Comparison of short-circuit characteristics of trench gate and planar gate U-shaped channel SOI-LIGBTs

Science.gov (United States)

Zhang, Long; Zhu, Jing; Sun, Weifeng; Zhao, Minna; Huang, Xuequan; Chen, Jiajun; Shi, Longxing; Chen, Jian; Ding, Desheng

2017-09-01

Comparison of short-circuit (SC) characteristics of 500 V rated trench gate U-shaped channel (TGU) SOI-LIGBT and planar gate U-shaped channel (PGU) SOI-LIGBT is made for the first time in this paper. The on-state carrier profile of the TGU structure is reshaped by the dual trenches (a gate trench G1 and a hole barrier trench G2), which leads to a different conduction behavior from that of the PGU structure. The TGU structure exhibits a higher latchup immunity but a severer self-heating effect. At current density (JC) 640 A/cm2. Comparison of layouts and fabrication processes are also made between the two types of devices.

Charge deposition model for investigating SE-microdose effect in trench power MOSFETs

International Nuclear Information System (INIS)

Wan Xin; Zhou Weisong; Liu Daoguang; Bo Hanliang; Xu Jun

2015-01-01

It was demonstrated that heavy ions can induce large current—voltage (I–V) characteristics shift in commercial trench power MOSFETs, named single event microdose effect (SE-microdose effect). A model is presented to describe this effect. This model calculates the charge deposition by a single heavy ion hitting oxide and the subsequent charge transport under an electric field. Holes deposited at the SiO 2 /Si interface by a Xe ion are calculated by using this model. The calculated results were then used in Sentaurus TCAD software to simulate a trench power MOSFET's I–V curve shift after a Xe ion has hit it. The simulation results are consistent with the related experiment's data. In the end, several factors which affect the SE-microdose effect in trench power MOSFETs are investigated by using this model. (paper)

Activity of Small Repeating Earthquakes along Izu-Bonin and Ryukyu Trenches

Science.gov (United States)

Hibino, K.; Matsuzawa, T.; Uchida, N.; Nakamura, W.; Matsushima, T.

2014-12-01

There are several subduction systems near the Japanese islands. The 2011 Mw9.0 Tohoku-oki megathrust earthquake occurred at the NE Japan (Tohoku) subduction zone. We have revealed a complementary relation between the slip areas for huge earthquakes and small repeating earthquakes (REs) in Tohoku. Investigations of REs in these subduction zones and the comparison with Tohoku area are important for revealing generation mechanism of megathrust earthquakes. Our target areas are Izu-Bonin and Ryukyu subduction zones, which appear to generate no large interplate earthquake. To investigate coupling of plate boundary in these regions, we estimated spatial distribution of slip rate by using REs. We use seismograms from the High Sensitivity Seismograph Network (Hi-net), Full Range Seismograph Network of Japan (F-net), and permanent seismic stations of Japan Meteorological Agency (JMA), Tohoku University, University of Tokyo, and Kagoshima University from 8 May 2003 (Izu-Bonin) and 14 July 2005 (Ryukyu) to 31 December 2012 to detect REs along the two trenches, by using similarity of seismograms. We mainly follow the procedure adopted in Uchida and Matsuzawa (2013) that studied REs in Tohoku area to compare our results with the REs in Tohoku. We find that the RE distribution along the Ryukyu trench shows two bands parallel to the trench axis. This feature is similar to the pattern in Tohoku where relatively large earthquakes occur between the bands. Along the Izu-Bonin trench, on the other hand, we find much fewer REs than in Tohoku or Ryukyu subduction zones and only one along-trench RE band, which corresponds to the area where the subducting Pacific plate contacts with the crust of the Philippine Sea plate. We also estimate average slip rate and coupling coefficient by using an empirical relationship between seismic moment and slip for REs (Nadeau and Johnson, 1998) and relative plate motion model. As a result, we find interplate slip rate in the deeper band is higher than

Paleoseismology of the Nephi Segment of the Wasatch Fault Zone, Juab County, Utah - Preliminary Results From Two Large Exploratory Trenches at Willow Creek

Science.gov (United States)

Machette, Michael N.; Crone, Anthony J.; Personius, Stephen F.; Mahan, Shannon; Dart, Richard L.; Lidke, David J.; Olig, Susan S.

2007-01-01

In 2004, we identified a small parcel of U.S. Forest Service land at the mouth of Willow Creek (about 5 km west of Mona, Utah) that was suitable for trenching. At the Willow Creek site, which is near the middle of the southern strand of the Nephi segment, the WFZ has vertically displaced alluvial-fan deposits >6-7 m, forming large, steep, multiple-event scarps. In May 2005, we dug two 4- to 5-m-deep backhoe trenches at the Willow Creek site, identified three colluvial wedges in each trench, and collected samples of charcoal and A-horizon organic material for AMS (acceleration mass spectrometry) radiocarbon dating, and sampled fine-grained eolian and colluvial sediment for luminescence dating. The trenches yielded a stratigraphic assemblage composed of moderately coarse-grained fluvial and debris-flow deposits and discrete colluvial wedges associated with three faulting events (P1, P2, and P3). About one-half of the net vertical displacement is accommodated by monoclinal tilting of fan deposits on the hanging-wall block, possibly related to massive ductile landslide deposits that are present beneath the Willow Creek fan. The timing of the three surface-faulting events is bracketed by radiocarbon dates and results in a much different fault chronology and higher slip rates than previously considered for this segment of the Wasatch fault zone.

Conceptual designs of near surface disposal facility for radioactive waste arising from the facilities using radioisotopes and research facilities for nuclear energy development and utilization

International Nuclear Information System (INIS)

Sakai, Akihiro; Yoshimori, Michiro; Okoshi, Minoru; Yamamoto, Tadatoshi; Abe, Masayoshi

2001-03-01

Various kinds of radioactive waste is generating from the utilization of radioisotopes in the field of science, technology, etc. and the utilization and development of nuclear energy. In order to promote the utilization of radionuclides and the research activities, it is necessary to treat and dispose of radioactive waste safely and economically. Japan Nuclear Cycle Development Institute (JNC), Japan Radioisotope Association (JRIA) and Japan Atomic Energy Research Institute (JAERI), which are the major waste generators in Japan in these fields, are promoting the technical investigations for treatment and disposal of the radioactive waste co-operately. Conceptual design of disposal facility is necessary to demonstrate the feasibility of waste disposal business and to determine the some conditions such as the area size of the disposal facility. Three institutes share the works to design disposal facility. Based on our research activities and experiences of waste disposal, JAERI implemented the designing of near surface disposal facilities, namely, simple earthen trench and concrete vaults. The designing was performed based on the following three assumed site conditions to cover the future site conditions: (1) Case 1 - Inland area with low groundwater level, (2) Case 2 - Inland area with high groundwater level, (3) Case 3 - Coastal area. The estimation of construction costs and the safety analysis were also performed based on the designing of facilities. The safety assessment results show that the safety for concrete vault type repository is ensured by adding low permeability soil layer, i.e. mixture of soil and bentonite, surrounding the vaults not depending on the site conditions. The safety assessment results for simple earthen trench also show that their safety is ensured not depending on the site conditions, if they are constructed above groundwater levels. The construction costs largely depend on the depth for excavation to build the repositories. (author)

Evaluation and design of drained low-level radioactive disposal sites. Final report

International Nuclear Information System (INIS)

Eichholz, G.G.

1984-12-01

Low-level disposal in shallow trenches has been the subject of much critical assessment in recent years. Historically most trenches have been located in fairly permeable settings and any liquid waste stored has migrated at rates limited mainly by hydraulic effects and the ion exchange capacity of underlying soil minerals. Attempts to minimize such seepage by choosing sites in very impermeable settings lead to overflow and surface runoff, whenever the trench cap is breached by subsidence or erosion. The work described in this report was directed to an optimum compromise situation where less reliance is placed on cap permanence, any ground seepage is directed and controlled, and the amount of waste leaching that would occur is minimized by keeping the soil surrounding the waste at only residual moisture levels at all times. Measurements have been conducted to determine these residual levels for some representative soils, to estimate the impact on waste migration of mainly unsaturated flow conditions, and to generate a conceptual design of a disposal facility which would provide adequate drainage to keep the waste from being exposed to continuous leaching by standing water. An attempt has also been made to quantify the reduced source terms under such periodic, unsaturated flow conditions, but those tests have not been conclusive to date. For low-permeability soils the waste should be placed about 1 ft. above the saturated layer formed by suction forces immediately above the gravel layer. Since most disposal sites, even in humid regions of the United States, are exposed only to intermittent rainfall and as most trench designs incorporate some gravel base for drainage, the results of this project have broader applications in assessing actual migration conditions in shallow trench disposal sites. Similar considerations may also apply to disposal of hazardous wastes

Paleoseismic evidence of earthquakes and tsunamis along the southern part of the Japan Trench

Science.gov (United States)

Pilarczyk, Jessica; Sawai, Yuki; Horton, Ben; Namegaya, Yuichi; Shinozaki, Tetsuya; Tanigawa, Koichiro; Matsumoto, Dan; Dura, Tina; Fujiwara, Osamu; Shishikura, Masanobu

2016-04-01

The northern part of the Japan Trench has frequently generated tsunamigenic-earthquakes with magnitudes up to ~M 8.0. In contrast, the middle and southern parts of the Japan Trench were considered relatively inactive until the 2011 Tohoku (M 9.0) event generated one of the largest tsunamis in recorded history. Geologic evidence from the Sendai plain revealed an event in CE 869 that could have forecast the severity of the Tohoku tsunami in 2011. Seismic models indicate that the Tohoku earthquake may have transferred stress southwards down the fault to the potentially locked southern part of the Japan Trench. This transfer of stress towards a locked section of the trench could produce an earthquake in the near future that would be comparable in magnitude to the Tohoku event. Reconstructing the history of individual great earthquakes and accompanying tsunamis using geological records from the coastal zone adjacent to the southern part of the Japan Trench provides an assessment of the seismic hazard for metropolitan areas in east-central Japan. We have found two anomalous marine sand layers intercalated with muddy peat, which can be traced 3.8 km inland and 5.5 km along the present Kujukuri coastline, approximately 50 km east of Tokyo. Both sand layers have features consistent with tsunami deposits, such as a distinct erosional base, rip-up clasts, normal grading, a mud drape, and marine foraminifera. Results of radiocarbon dating constrain the age of the upper sand to 337 - 299 cal. yrs. BP, which likely corresponds to the only known southern Japan Trench rupture ever recorded, the Empo tsunami of CE 1677. The age of the lower sand is 979 - 903 cal. yrs. BP; marking an event for which there is no historical documentation at present. Preliminary tsunami simulation models indicate that a middle trench (Tohoku-style) rupture is not responsible for significant inundation of the Kujukuri coastline and would likely not have been capable of depositing either sand layer

Biodiversity of nematode assemblages from deep-sea sediments of the Atacama Slope and Trench (South Pacific Ocean)

Science.gov (United States)

Gambi, C.; Vanreusel, A.; Danovaro, R.

2003-01-01

Nematode assemblages were investigated (in terms of size spectra, sex ratio, Shannon diversity, trophic structure and diversity, rarefaction statistics, maturity index, taxonomic diversity and taxonomic distinctness) at bathyal and hadal depths (from 1050 to 7800 m) in the deepest trench of the South Pacific Ocean: the Trench of Atacama. This area, characterised by very high concentrations of nutritionally-rich organic matter also at 7800-m depth, displayed characteristics typical of eutrophic systems and revealed high nematode densities (>6000 ind. 10 cm -2). Nematode assemblages from the Atacama Trench displayed a different composition than at bathyal depths. At bathyal depths 95 genera and 119 species were found (Comesomatidae, Cyatholaimidae, Microlaimidae, Desmodoridae and Xyalidae being dominant), whereas in the Atacama Trench only 29 genera and 37 species were encountered (dominated by Monhysteridae, Chromadoridae, Microlaimidae, Oxystominidae and Xyalidae). The genus Monhystera (24.4%) strongly dominated at hadal depths and Neochromadora, and Trileptium were observed only in the Atacama Trench, but not at bathyal depths. A reduction of the mean nematode size (by ca. 67%) was observed between bathyal and hadal depths. Since food availability was not a limiting factor in the Atacama Trench sediments, other causes are likely to be responsible for the reduction of nematode species richness and body size. The presence of a restricted number of families and genera in the Atacama Trench might indicate that hadal sediments limited nematode colonisation. Most of the genera reaching very high densities in Trench sediments (e.g., Monhystera) are opportunistic and were responsible for the significant decrease of the maturity index. The dominance of opportunists, which are known to be characterised by small sizes, might have contributed to the reduced nematode size at hadal depths. Shannon diversity and species richness decreased in hadal water depth and this pattern

Closure Report for Corrective Action Unit 426: Cactus Spring Waste Trenches, Tonopah Test Range, Nevada

Energy Technology Data Exchange (ETDEWEB)

Dave Madsen

1998-08-01

This Closure Report provides the documentation for closure of the Cactus Spring Waste Trenches Corrective Action Unit (CAU) 426. The site is located on the Tonopah Test Range, approximately 225 kilometers northwest of Las Vegas, NV. CAU 426 consists of one corrective action site (CAS) which is comprised of four waste trenches. The trenches were excavated to receive solid waste generated in support of Operation Roller Coaster, primary the Double Tracks Test in 1963, and were subsequently backfilled. The Double Tracks Test involved use of live animals to assess the biological hazards associated with the nonnuclear detonation of plutonium-bearing devices. The Nevada Division of Environmental Protection approved Corrective Action Plan (CAP)which proposed ''capping'' methodology. The closure activities were completed in accordance with the approved CAP and consisted of constructing an engineered cover in the area of the trenches, constructing/planting a vegetative cover, installing a perimeter fence and signs, implementing restrictions on future use, and preparing a Post-Closure Monitoring Plan.

Removal of the radioactive materials from the trench submergence in Fukushima

International Nuclear Information System (INIS)

Okita, Takeshi; Ikeda, Akira; Oomura, Hisao; Kojima, Chiaki; Nozawa, Keiji

2014-01-01

Toshiba has been contributing for stabilization from the accident of Fukushima Daiichi nuclear power plant. One of the contribution areas is the treatment of highly contaminated water accumulated in the piping trench of Unit 2 and Unit 3. As an emergency countermeasure, Toshiba installed the mobile type water treatment system which is named SMARTS (Simplified Mobile Adsorption and Retrieve for Trench Submergence) for removal of radionuclide. SMARTS has achieved 10 3 ∼ 10 4 decontamination factor (DF) for Cesium (Cs) in the actual operation. This paper describes the formation of SMARTS and the result of performance. (author)

40Ar-39Ar dating of hornfels dredged near the Japan trench

International Nuclear Information System (INIS)

Takigami, Yutaka; Fujioka, Kantaro

1989-01-01

During the KH 81-3 Cruise of the R/V Hakuho-Maru, biotite-bearing hornfelses were dredged from the landward slope of the Japan Trench. Bulk sample and separated biotite were dated by the 40 Ar- 39 Ar method and they showed 40 Ar- 39 Ar ages of 28.9±1.4 Ma and 28.5±1.4 Ma, respectively. This would indicate that biotite was formed at about 29 Ma by the thermal metamorphism which might have related with some magmatic activity. In this magmatic activity was caused by the subducting oceanic plate in the similar conditions at present, it seems to have occurred at a place too close to the present trench axis. This discrepancy could be explained by such processes as the change of the angle of the subducting plate, the moving of the trench axis by tectonic erosion and so on. However, more age data are required to solve this discrepancy. (author)

On-site infiltration of road runoff using pervious pavements with subjacent infiltration trenches as source control strategy.

Science.gov (United States)

Fach, S; Dierkes, C

2011-01-01

The focus in this work was on subsoil infiltration of stormwater from parking lots. With regard to operation, reduced infiltration performance due to clogging and pollutants in seepage, which may contribute to contaminate groundwater, are of interest. The experimental investigation covered a pervious pavement with a subjacent infiltration trench draining an impervious area of 2 ha. In order to consider seasonal effects on the infiltration performance, the hydraulic conductivity was measured tri-monthly during monitoring with a mobile sprinkling unit. To assess natural deposits jointing, road bed, gravel of infiltration trenches and subsoil were analysed prior to commencement of monitoring for heavy metals, polycyclic aromatic and mineral oil type hydrocarbons. Furthermore, from 22 storm events, water samples of rainfall, surface runoff, seepage and ground water were analysed with regard to the above mentioned pollutants. The study showed that the material used for the joints had a major impact on the initial as well as the final infiltration rates. Due to its poor hydraulic conductivity, limestone gravel should not be used as jointing. Furthermore, it is recommended that materials for the infiltration facilities are ensured free of any contaminants prior to construction. Polycyclic aromatic and mineral oil type hydrocarbons were, with the exception of surface runoff, below detection limits. Heavy metal concentrations of groundwater were with the exception of lead (because of high background concentrations), below the permissible limits.

Theoretical Investigation of Inter-core Crosstalk Properties in Homogeneous Trench-Assisted Multi-Core Fibers

DEFF Research Database (Denmark)

Ye, Feihong; Morioka, Toshio; Tu, Jiajing

2014-01-01

We derive analytical expressions for inter-core crosstalk, its dependence on core pitch and wavelength in homogeneous trench-assisted multi-core fibers. They are in excellent agreement with numerical simulation results.......We derive analytical expressions for inter-core crosstalk, its dependence on core pitch and wavelength in homogeneous trench-assisted multi-core fibers. They are in excellent agreement with numerical simulation results....

A trench study to assess transfer of pesticides in subsurface lateral flow for a soil with contrasting texture on a sloping vineyard in Beaujolais.

Science.gov (United States)

Peyrard, X; Liger, L; Guillemain, C; Gouy, V

2016-01-01

Subsurface lateral flow in both texture-contrast soils and catchments with shallow bedrock is suspected to be a non-point source of contamination of watercourses by pesticides used in agriculture. As a case study, the north of the Beaujolais region (eastern France) provides a favorable environment for such contamination due to its agro-pedo-climatic conditions. Environments seen in the Beaujolais region include intense viticulture, permeable and shallow soils, steep hillslopes, and storms that occur during the periods of pesticide application. Watercourse contamination by pesticides has been widely observed in this region, and offsite pesticide transport by subsurface lateral flow is suspected to be involved in diffuse and chronic presence of pesticides in surface water. In order to confirm and quantify the potential role of such processes in pesticide transfer, an automated trench system has been designed. The trench was set up on a steep farmed hillslope in a texture-contrast soil. It was equipped with a tipping bucket flow meter and an automatic sampler to monitor pesticide concentrations in lateral flow at fine resolution, by means of a flow-dependent sampling strategy. Four pesticides currently used in vine growing were studied to provide a range of mobility properties: one insecticide (chlorpyrifos-methyl) and three fungicides (spiroxamine, tebuconazole, and dimethomorph). With this system, it was possible to study pesticide concentration dynamics in the subsurface lateral flow, generated by substantial rainfall events following pesticide applications. The experimental design ascertained to be a suitable method in which to monitor subsurface lateral flow and related transfer of pesticides.

Geological mapping of investigation trench OL-TK14 at the Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Nordbaeck, N.

2007-12-01

Geological mapping of investigation trench OL-TK14 was carried out by the Geological Survey of Finland at the Olkiluoto study site, Eurajoki, as part of Posiva Oy's site investigation programme for the development of an underground repository for nuclear waste. The E-W striking, ca. 215 m long trench is located in the eastern part of the Olkiluoto Island adjacent to boreholes OL-KR40 and OL-KR45. The trench was cleaned with a pressure washer and pressurized air. The rock types were determined macroscopically. Five samples were also investigated microscopically. The main rock type in the trench is veined gneiss. A few less than 0.5 m wide coarsegrained pegmatitic granite dykes are also encountered. Furthermore a large number of mica gneiss, quartz gneiss and skarn inclusions are present in the veined gneiss, being often elongated and parallel to the foliation. The most dominant tectonic feature is the foliation S2 and associated intense granitic leucosome veining. The foliation strikes ENE-WSW and dips steeply towards SES. Intensely to moderately banded rocks dominate the trench. The sparse F3 folds observed in OL-TK14 are small-scale tight folds in leucosome veins. A large-scale (10 m) open bending of the foliation that could be a result of D4 folding was also observed. Shearbands and other signs of ductile shearing were observed on many locations in the trench and in the eastern part there is a high-grade ductile shear zone intersection. During the fracture mapping, all fractures intersecting the central thread were investigated and a total of 684 fractures were recorded. The average fracture density of the trench is 3.18 fractures/m. On the basis of fracture orientations three main sets can be distinguished: 1) a set striking N-S with vertical dip, 2) a ENE-WSW striking set with varying dips towards the SSE (parallel to the foliation) and 3) a NE-SW striking set with sub-vertical dip towards the SE or the NW. Most of the measured fractures are short due to the

Design and construction of a low-level waste shallow land burial experimental facility

International Nuclear Information System (INIS)

Boegly, W.J. Jr.; Davis, E.C.

1983-11-01

The Environmental Sciences Division (ESD) of the Oak Ridge National Laboratory (ORNL) has been investigating improved shallow land burial (SLB) practices for disposing of low-level radioactive wastes in humid environments. Two improvements currently being studied are the use of a cement-bentonite grout applied to waste trenches before they are covered and the use of an impermeable Hypalon fabric liner, which completely surrounds the waste in a trench. A field-scale demonstration site, known as the Engineered Test Facility (ETF), has been established for these studies in the complex geologic setting typical of the Oak Ridge area. Design of the ETF was initiated in 1980 for purposes of (1) evaluating the ability of the grouted and lined trench treatments to minimize water contact and concurrent waste leaching, (2) evaluating selected waste disposal site characterization criteria, (3) integrating site characterization data into model development, and (4) validating the ETF site model and using it to predict long-term site performance. A total of nine trenches (six treated and three control) were excavated at the site in June of 1981. Bales of ORNL compacted waste were used to fill the 3m x 3m x 3m trenches, and, after treatment, all trenches were closed (backfilled and covered) according to current practice. Evaluation of the trench treatments is in progress using a series of inorganic and organic tracer tests designed to monitor water movement in three regions of interest: the trenches, the unsaturated zone around the trenches, and the saturated zone below the site. A successful demonstration of reduced waste leaching resulting from either of these two trench modifications described in this design and construction report will have immediate application to larger disposal sites having similar water-related problems. 9 references, 14 figures, 3 tables

Geological mapping of investigation trench OL-TK9 at the Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Nordbaeck, N.; Talikka, M.

2006-07-01

Geological mapping of trench OL-TK9 was carried out the by the Geological Survey of Finland at the Olkiluoto study site, Eurajoki, southwestern Finland, as a part of Posiva Oy's site investigation programme for the development of an underground repository for nuclear waste. The NW-SE striking trench, which is about 371 metres in length and 0.4-2.5 metres in width, is situated to the west from the OL-TK3 in the northwestern part of the study site. The rock types were determined macroscopically and the main rock types were further investigated microscopically. On the basis of the migmatite structure, the migmatitic gneisses at Olkiluoto can be divided into three groups: veined gneiss, stromatic gneiss and diatexitic gneiss. Most of the migmatitic gneisses in the trench are veined gneisses and only a few short sections of the diatexitic gneiss or K-feldspar porphyry exist. Stromatic gneisses were not encountered. The leucosome of the veined gneiss show vein like, more or less linear traces with some features similar to large-scale augen structures, whereas the migmatitic structure of the diatexitic gneiss is more asymmetric and irregular. The southernmost part of the trench is dominated by mica gneiss and pegmatitic granite. The mica gneiss is homogenous mica-rich rock that contains less than 10 % granite leucosome material. The pegmatitic granite shows variations in grain size, colour, and mode of occurrence. The veined gneiss dominates the central part of the trench. The northernmost part of the trench is mainly comprised of tonalitic-granodioritic-granitic gneiss, which has an igneous character. Most rocks in the trench are altered, the intensity of the alteration varies from weak to strong, and the most common alteration type is chloritisation. The intense alteration has resulted in pervasive softening and weathering of the bedrock in places and up to four meters thick layers of strongly weathered rocks were observed on the edges of the trench. The foliation S2B

Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS.

Corrective action plan for CAU No. 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range

International Nuclear Information System (INIS)

1997-07-01

This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Roller Coaster Sewage Lagoons and North Disposal Trench Corrective Action Unit (CAU) No. 404. The site is located on the Tonopah Test Range. CAU 404 consists of two Corrective Action Sites (CAS): the Roller Coaster Lagoons (CAS No TA-03-001-TA-RC) and the North Disposal Trench (CAS No TA-21-001-TA-RC). A site map of the lagoons and trench is provided. The Roller Coaster Sewage Lagoons are comprised of two unlined lagoons that received liquid sanitary waste in 1963 from the Operation Roller Coaster Man Camp and debris from subsequent construction and range cleanup activities. The North Disposal Trench was excavated in approximately 1963 and received solid waste and debris from the man camp and subsequent construction and range cleanup activities. A small hydrocarbon spill occurred during the 1995 Voluntary Corrective Action (VCA) activities in an area associated with the North Disposal Trench CAS

Close-range geophotogrammetric mapping of trench walls using multi-model stereo restitution software

Energy Technology Data Exchange (ETDEWEB)

Coe, J.A.; Taylor, E.M.; Schilling, S.P.

1991-06-01

Methods for mapping geologic features exposed on trench walls have advanced from conventional gridding and sketch mapping to precise close-range photogrammetric mapping. In our study, two strips of small-format (60 {times} 60) stereo pairs, each containing 42 photos and covering approximately 60 m of nearly vertical trench wall (2-4 m high), were contact printed onto eight 205 {times} 255-mm transparent film sheets. Each strip was oriented in a Kern DSR15 analytical plotter using the bundle adjustment module of Multi-Model Stereo Restitution Software (MMSRS). We experimented with several systematic-control-point configurations to evaluate orientation accuracies as a function of the number and position of control points. We recommend establishing control-point columns (each containing 2-3 points) in every 5th photo to achieve the 7-mm Root Mean Square Error (RMSE) accuracy required by our trench-mapping project. 7 refs., 8 figs., 1 tab.

Close-range geophotogrammetric mapping of trench walls using multi-model stereo restitution software

International Nuclear Information System (INIS)

Coe, J.A.; Taylor, E.M.; Schilling, S.P.

1991-01-01

Methods for mapping geologic features exposed on trench walls have advanced from conventional gridding and sketch mapping to precise close-range photogrammetric mapping. In our study, two strips of small-format (60 x 60) stereo pairs, each containing 42 photos and covering approximately 60 m of nearly vertical trench wall (2-4 m high), were contact printed onto eight 205 x 255-mm transparent film sheets. Each strip was oriented in a Kern DSR15 analytical plotter using the bundle adjustment module of Multi-Model Stereo Restitution Software (MMSRS). We experimented with several systematic-control-point configurations to evaluate orientation accuracies as a function of the number and position of control points. We recommend establishing control-point columns (each containing 2-3 points) in every 5th photo to achieve the 7-mm Root Mean Square Error (RMSE) accuracy required by our trench-mapping project. 7 refs., 8 figs., 1 tab

Soil prokaryotic communities in Chernobyl waste disposal trench T22 are modulated by organic matter and radionuclide contamination.

Science.gov (United States)

Theodorakopoulos, Nicolas; Février, Laureline; Barakat, Mohamed; Ortet, Philippe; Christen, Richard; Piette, Laurie; Levchuk, Sviatoslav; Beaugelin-Seiller, Karine; Sergeant, Claire; Berthomieu, Catherine; Chapon, Virginie

2017-08-01

After the Chernobyl nuclear power plant accident in 1986, contaminated soils, vegetation from the Red Forest and other radioactive debris were buried within trenches. In this area, trench T22 has long been a pilot site for the study of radionuclide migration in soil. Here, we used 454 pyrosequencing of 16S rRNA genes to obtain a comprehensive view of the bacterial and archaeal diversity in soils collected inside and in the vicinity of the trench T22 and to investigate the impact of radioactive waste disposal on prokaryotic communities. A remarkably high abundance of Chloroflexi and AD3 was detected in all soil samples from this area. Our statistical analysis revealed profound changes in community composition at the phylum and OTUs levels and higher diversity in the trench soils as compared to the outside. Our results demonstrate that the total absorbed dose rate by cell and, to a lesser extent the organic matter content of the trench, are the principal variables influencing prokaryotic assemblages. We identified specific phylotypes affiliated to the phyla Crenarchaeota, Acidobacteria, AD3, Chloroflexi, Proteobacteria, Verrucomicrobia and WPS-2, which were unique for the trench soils. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Annual report, RCRA post-closure monitoring and inspections for the mercury landfill hazardous waste trenches for the period October 1995--October 1996

Energy Technology Data Exchange (ETDEWEB)

Emer, D.F.; Smith, J.L.

1997-01-01

The Area 23 Hazardous Waste Trenches were closed in-place in September 1993. Post-closure monitoring of the Area 23 Hazardous Waste Trenches began in October 1993. The post-closure monitoring program is used to verify that the Area 23 Hazardous Waste Trench covers are performing properly, and that there is no water infiltrating into the waste trenches. The performance of the Area 23 Hazardous Waste Trenches is currently monitored using 30 neutron access tubes positioned on and along the margins of the covers. Soil moisture measurements are obtained in the soils directly beneath the trenches and compared to baseline conditions from the first year of post-closure operation. This report documents the post-closure activities between October 1995 and October 1996.

Annual report, RCRA post-closure monitoring and inspections for the mercury landfill hazardous waste trenches for the period October 1995--October 1996

International Nuclear Information System (INIS)

Emer, D.F.; Smith, J.L.

1997-01-01

The Area 23 Hazardous Waste Trenches were closed in-place in September 1993. Post-closure monitoring of the Area 23 Hazardous Waste Trenches began in October 1993. The post-closure monitoring program is used to verify that the Area 23 Hazardous Waste Trench covers are performing properly, and that there is no water infiltrating into the waste trenches. The performance of the Area 23 Hazardous Waste Trenches is currently monitored using 30 neutron access tubes positioned on and along the margins of the covers. Soil moisture measurements are obtained in the soils directly beneath the trenches and compared to baseline conditions from the first year of post-closure operation. This report documents the post-closure activities between October 1995 and October 1996

Grout testing and characterization for shallow-land burial trenches at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Tallent, O.K.; Sams, T.L.; Tamura, T.; Godsey, T.T.; Francis, C.L.; McDaniel, E.W.

1986-10-01

An investigation was conducted to develop grout formulations suitable for in situ stabilization of low-level and transuranic (TRU) waste in shallow-land burial trenches at Idaho National Engineering Laboratory (INEL). The acceptabilities of soil, ordinary particulate, and fine particulate grouts were evaluated based on phase separation, compressive strength, freeze/thaw, penetration resistance, rheological, water permeability, column, and other tests. Soil grouts with soil-to-cement weight ratios from 0.91 to 1.60 were found to be suitable for open trench or drum disposal. Ordinary particulate grouts containing type I,II Portland cement, class C fly ash, bentonite, water, and a fluidizer were formulated to fill large voids within the soil/waste matrix of a closed shallow-land burial trench. Fine particulate grouts containing fine (mean particle size, 9.6 m) cement and water were formulated to fill smaller voids and to establish a grout-soil barrier to prevent water intrusion into the grouted waste trench. Solution, or chemical grouts, were evaluated as possible substitutes for the fine particulate grouts

Hydrogen-terminated diamond vertical-type metal oxide semiconductor field-effect transistors with a trench gate

Energy Technology Data Exchange (ETDEWEB)

Inaba, Masafumi, E-mail: inaba-ma@ruri.waseda.jp; Muta, Tsubasa; Kobayashi, Mikinori; Saito, Toshiki; Shibata, Masanobu; Matsumura, Daisuke; Kudo, Takuya; Hiraiwa, Atsushi [Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kawarada, Hiroshi [Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku, Tokyo 169-0051 (Japan)

2016-07-18

The hydrogen-terminated diamond surface (C-H diamond) has a two-dimensional hole gas (2DHG) layer independent of the crystal orientation. A 2DHG layer is ubiquitously formed on the C-H diamond surface covered by atomic-layer-deposited-Al{sub 2}O{sub 3}. Using Al{sub 2}O{sub 3} as a gate oxide, C-H diamond metal oxide semiconductor field-effect transistors (MOSFETs) operate in a trench gate structure where the diamond side-wall acts as a channel. MOSFETs with a side-wall channel exhibit equivalent performance to the lateral C-H diamond MOSFET without a side-wall channel. Here, a vertical-type MOSFET with a drain on the bottom is demonstrated in diamond with channel current modulation by the gate and pinch off.

A comparative study of two shovel designs.

Science.gov (United States)

Degani, A; Asfour, S S; Waly, S M; Koshy, J G

1993-10-01

In the present study a modified shovel design with two perpendicular shafts is presented. This modified, two-shaft shovel was compared with a regular shovel. The modified shovel was evaluated and tested in a controlled laboratory environment using surface electromyography recorded from the lumbar paraspinal muscles. The new shovel design was also tested in a field study using ratings of perceived exertion. The results indicate that there was a significant reduction in EMG values of the lumbar paraspinal muscles and a consistent reduction in perceived exertion ratings while the modified shovel was being used for removing dirt in digging trenches up to 90 cm in depth.

Study on filling materials suitable for seawater piping trench closure work at Fukushima Daiichi Nuclear Power Plant

International Nuclear Information System (INIS)

Yanai, Shuji; Hibi, Yasuki; Nishikori, Kazumasa; Sato, Keita

2016-01-01

Highly contaminated water leaking from the reactor buildings and turbine buildings damaged by the 2011 Great East Japan Earthquake has accumulated in the seawater piping trenches of Fukushima Daiichi Nuclear Power Station Units 2, 3, and 4. In November 2014, work commenced to replace and remove this contaminated water by filling the trenches with filling materials, and this work was completed in December 2015. This paper summarizes the contents of this study on various filling materials, including special fillers with long-distance underwater flowability applied to the horizontal tunnel parts of the trenches. (author)

Timing of Late Holocene surface rupture of the Wairau Fault, Marlborough, New Zealand

International Nuclear Information System (INIS)

Zachariasen, J.; Berryman, K.R.; Langridge, R.M.; Prentice, C.; Rymer, M.; Stirling, M.W.; Villamor, P.

2006-01-01

Three trenches excavated across the central portion of the right-lateral strike-slip Wairau Fault in South Island, New Zealand, exposed a complex set of fault strands that have displaced a sequence of late Holocene alluvial and colluvial deposits. Abundant charcoal fragments provide age control for various stratigraphic horizons dating back to c. 5610 yr ago. Faulting relations from the Wadsworth trench show that the most recent surface rupture event occurred at least 1290 yr and at most 2740 yr ago. Drowned trees in landslide-dammed Lake Chalice, in combination with charcoal from the base of an unfaulted colluvial wedge at Wadsworth trench, suggest a narrower time bracket for this event of 1811-2301 cal. yr BP. The penultimate faulting event occurred between c. 2370 and 3380 yr, and possibly near 2680 ± 60 cal. yr BP, when data from both the Wadsworth and Dillon trenches are combined. Two older events have been recognised from Dillon trench but remain poorly dated. A probable elapsed time of at least 1811 yr since the last surface rupture, and an average slip rate estimate for the Wairau Fault of 3-5 mm/yr, suggests that at least 5.4 m and up to 11.5 m of elastic shear strain has accumulated since the last rupture. This is near to or greater than the single-event displacement estimates of 5-7 m. The average recurrence interval for surface rupture of the fault determined from the trench data is 1150-1400 yr. Although the uncertainties in the timing of faulting events and variability in inter-event times remain high, the time elapsed since the last event is in the order of 1-2 times the average recurrence interval, implying that the Wairau Fault is near the end of its interseismic period. (author). 44 refs., 10 figs., 1 tab

The distribution of radionuclides and some trace metals in the water columns of the Japan and Bonin trenches

International Nuclear Information System (INIS)

Nozari, Y.; Yamada, M.; Shitashima, K.; Tsubota, H.

1998-01-01

Presented here is the first geochemical data on the U/Th series Th, Pa, Ac, and Pb isotopes and artificial fallout radionuclides ( 90 Sr, 137 Cs, and Pu isotopes), and some trace elements (V, Zn, Cd, Cu, Mn, and Ni) in two water columns of the Japan and Bonin trenches down to the bottom depths of 7585 m and 9750 m, respectively. Hydrographic properties such as temperature, salinity dissolved oxygen, and nutrient content within the trench valley remain constant at the same levels as those in the bottom water of the Northwest Pacific basin (typically ∼6000 m in depth). The radionuclide activities and most trace metal concentrations are also not very different from those in the overlying water at depths of around 5000-6000 m. This means that any chemical alteration which sea water undergoes during its residence within the trench was not obviously detected by the techniques used here. The suggestion follows that the trench water is rather freely communicating y isopycnal mixing with the bottom water overlying the Northwest Pacific abyssal plain. The trench waters contain high 239,240 Pu activities throughout, indicating that Pu is actively regenerating from rapidly sinking, large particles at the bottom interface, probably due to a change in the oxidation state. On the other hand, the vertical profiles of 210 Pb and 231 Pa show lower activities within the trench than those in the overlying deep waters, suggesting that the effect of boundary and bottom scavenging is significant in controlling their oceanic distributions. However, none of the trace metals studied here obviously follows the behaviour of the above nuclides. The 228 Th data show scattering within the Bonin Trench that is largely ascribable to analytical errors. If, however we accept that the scatter of 228 Th data is real and the variation is caused solely by decay of its parent 228 Ra, we can set an upper limit of ∼5 years for the renewal time of the trench water. (authors)

Elasto-plastic deformation and plate weakening due to normal faulting in the subducting plate along the Mariana Trench

Science.gov (United States)

Zhou, Zhiyuan; Lin, Jian

2018-06-01

We investigated variations in the elasto-plastic deformation of the subducting plate along the Mariana Trench through an analysis of flexural bending and normal fault characteristics together with geodynamic modeling. Most normal faults were initiated at the outer-rise region and grew toward the trench axis with strikes mostly subparallel to the local trench axis. The average trench relief and maximum fault throws were measured to be significantly greater in the southern region (5 km and 320 m, respectively) than the northern and central regions (2 km and 200 m). The subducting plate was modeled as an elasto-plastic slab subjected to tectonic loading at the trench axis. The calculated strain rates and velocities revealed an array of normal fault-like shear zones in the upper plate, resulting in significant faulting-induced reduction in the deviatoric stresses. We then inverted for solutions that best fit the observed flexural bending and normal faulting characteristics, revealing normal fault penetration to depths of 21, 20, and 32 km beneath the seafloor for the northern, central, and southern regions, respectively, which is consistent with the observed depths of the relocated normal faulting earthquakes in the central Mariana Trench. The calculated deeper normal faults of the southern region might lead to about twice as much water being carried into the mantle per unit trench length than the northern and central regions. We further calculated that normal faulting has reduced the effective elastic plate thickness Te by up to 52% locally in the southern region and 33% in both the northern and central regions. The best-fitting solutions revealed a greater apparent angle of the pulling force in the southern region (51-64°) than in the northern (22-35°) and central (20-34°) regions, which correlates with a general southward increase in the seismically-determined dip angle of the subducting slab along the Mariana Trench.

Chasing the Ghost of Melesina Trench: A film by Qina Liu in collaboration with Katharine Kittredge

Directory of Open Access Journals (Sweden)

Katherine Kittredge

2013-04-01

Full Text Available Filmmaker Qina Liu has created a short documentary about Katharine Kittredge's decade-long quest to learn about the life and work of Anglo-Irish diarist and poet Melesina Trench. The story tells of remarkable coincidences, documents lost and found, and the emergence of Trench's descendants in the project's final chapter.

THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS

Energy Technology Data Exchange (ETDEWEB)

BENECKE, MN.W.

2006-02-22

A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50 acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity, and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy. It is

78 FR 7385 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

Science.gov (United States)

2013-02-01

...-BA98 Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll... Presidential proclamations that created the Marianas Trench, Pacific Remote Islands, and Rose Atoll Marine..., 2009). Proclamation 8337 of January 6, 2009, ``Establishment of the Rose Atoll Marine National Monument...

Trench motion-controlled slab morphology and stress variations: Implications for the isolated 2015 Bonin Islands deep earthquake

Science.gov (United States)

Yang, Ting; Gurnis, Michael; Zhan, Zhongwen

2017-07-01

The subducted old and cold Pacific Plate beneath the young Philippine Sea Plate at the Izu-Bonin trench over the Cenozoic hosts regional deep earthquakes. We investigate slab morphology and stress regimes under different trench motion histories with mantle convection models. Viscosity, temperature, and deviatoric stress are inherently heterogeneous within the slab, which we link to the occurrence of isolated earthquakes. Models expand on previous suggestions that observed slab morphology variations along the Izu-Bonin subduction zone, exhibited as shallow slab dip angles in the north and steeper dip angles in the south, are mainly due to variations in the rate of trench retreat from the north (where it is fast) to the south (where it is slow). Geodynamic models consistent with the regional plate tectonics, including oceanic plate age, plate convergence rate, and trench motion history, reproduce the seismologically observed principal stress direction and slab morphology. We suggest that the isolated 680 km deep, 30 May 2015 Mw 7.9 Bonin Islands earthquake, which lies east of the well-defined Benioff zone and has its principal compressional stress direction oriented toward the tip of the previously defined Benioff zone, can be explained by Pacific slab buckling in response to the slow trench retreat.

The potential influence of subduction zone polarity on overriding plate deformation, trench migration and slab dip angle

NARCIS (Netherlands)

Schellart, W. P.

2007-01-01

A geodynamic model exists, the westward lithospheric drift model, in which the variety of overriding plate deformation, trench migration and slab dip angles is explained by the polarity of subduction zones. The model predicts overriding plate extension, a fixed trench and a steep slab dip for

Removal of nanoparticles from plain and patterned surfaces using nanobubbles

NARCIS (Netherlands)

Yang, S.; Duisterwinkel, A.E.

2011-01-01

It is the aim of this paper to quantitatively characterize the capability of surface nanobubbles for surface cleaning, i.e., removal of nanodimensioned polystyrene particles from the surface. We adopt two types of substrates: plain and nanopatterned (trench/ridge) silicon wafer. The method used to

Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 1–4, San Andreas Fault Zone, southern California (2007–2009)

Science.gov (United States)

Scharer, Katherine M.; Fumal, Tom E.; Weldon, Ray J.; Streig, Ashley R.

2014-01-01

The Frazier Mountain paleoseismic site is located at the northwest end of the Mojave section of the San Andreas Fault, in a small, closed depression at the base of Frazier Mountain near Tejon Pass, California (lat 34.8122° N., long 118.9034° W.). The site was known to contain a good record of earthquakes due to previous excavations by Lindvall and others (2002). This report provides data resulting from four nested excavations, or cuts, along trench 1 (T1) in 2007 and 2009 at the Frazier Mountain site. The four cuts were excavated progressively deeper and wider in an orientation perpendicular to the San Andreas Fault, exposing distal fan and marsh sediments deposited since ca. A.D. 1200. The results of the trenching show that earthquakes that ruptured the site have repeatedly produced a small depression or sag on the surface, which is subsequently infilled with sand and silt deposits. This report provides high-resolution photomosaics and logs for the T1 cuts, a detailed stratigraphic column for the deposits, and a table summarizing all of the evidence for ground rupturing paleoearthquakes logged in the trenches.

Geotechnical analysis of soil samples from test trench at Western New York Nuclear Service Center, West Valley, New York

International Nuclear Information System (INIS)

Fickies, R.H.; Fakundiny, R.H.; Mosley, E.T.

1979-04-01

In July 1977, a deep research trench was excavated and soil samples collected at the Western New York Nuclear Services Center, West Valley, NY. The glacial till horizons sampled are considered to be representative of the till serving as a burial medium at the nearby low-level radioactive waste burial ground. A series of laboratory tests were conducted consisting of unit weight, moisture content, Atterberg limits, unconfined compression, dispersion, swell, permeability, and consolidation. These laboratory analyses and field observations indicate that the till exposed in the research trench is a generally dense mixture of silt and clay of low to medium plasticity, with minor amounts of fine to coarse sand and fine gravel. The till has a generally low coefficient of permeability in the range of 10 -7 cm/s horizontal and 10 -8 cm/s vertical. A network of vertical fractures exists in the upper 15 feet of weathered till which may allow some downward percolation of surface runoff. The test data indicates that the maximum depth to which these fractures could possibly penetrate is 50 feet

Advocacy for Kids: A View from the Residential Trenches.

Science.gov (United States)

Parsons, Jon R.

1995-01-01

Presents the concept of advocacy in the trenches, wherein residential care staff intercede with and for dysfunctional families, dysfunctional children, and the bureaucracy. This advocacy emphasizes individualized treatment and case-by-case networking, focusing not on broad causes but on what is in the best interest of each child. (ET)

PROJECT-SPECIFIC TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 3 TRENCH 1, BROOKHAVEN NATIONAL LABORATORY UPTON, NEW YORK

International Nuclear Information System (INIS)

Harpenau, E.M.

2010-01-01

The Oak Ridge Institute for Science and Education (ORISE) has reviewed the project documentation and data for the High Flux Beam Reactor (HFBR) Underground Utilities removal Phase 3; Trench 1 at Brookhaven National Laboratory (BNL) in Upton, New York. The Brookhaven Survey Group (BSG) has completed removal and performed Final Status Survey (FSS) of the 42-inch duct and 14-inch line in Trench 1 from Building 801 to the Stack. Sample results have been submitted as required to demonstrate that the cleanup goal of (le)15 mrem/yr above background to a resident in 50 years has been met. Four rounds of sampling, from pre-excavation to FSS, were performed as specified in the Field Sampling Plan (FSP) (BNL 2010a). It is the policy of the U.S. Department of Energy (DOE) to perform independent verifications of decontamination and decommissioning activities conducted at DOE facilities. ORISE has been designated as the organization responsible for this task for the HFBR Underground Utilities. ORISE, together with DOE, determined that a Type A verification of Trench 1 was appropriate based on recent verification results from Trenches 2, 3, 4, and 5, and the minimal potential for residual radioactivity in the area. The removal of underground utilities has been performed in three stages to decommission the HFBR facility and support structures. Phase 3 of this project included the removal of at least 200 feet of 36-inch to 42-inch duct from the west side to the south side of Building 801, and the 14-inch diameter Acid Waste Line that spanned from 801 to the Stack within Trench 1. Based on the pre-excavation sample results of the soil overburden, the potential for contamination of the soil surrounding the pipe is minimal (BNL 2010a). ORISE reviewed the gamma spectroscopy results for 14 FSS soil samples, four core samples, and one duplicate sample collected from Trench 1. Sample results for the radionuclides of concern were below the established cleanup goals. However, in sample PH-3

Dose and risk assessment of norm Contaminated waste released from trench disposal facility

International Nuclear Information System (INIS)

Abdel Geleel, M.; Ramadan, A.B.; Tawfik, A.A.

2005-01-01

Oil and gas extraction and processing operations accumulate naturally occurring radioactive material (NORM) at concentrations above normal in by-product waste streams. The petroleum industry adopted methods for managing of NORM that are more restrictive than past practices and are likely to provide greater isolation of the radioactivity. Trench was used as a disposal facility for NORM contaminated wastes at one site of the petroleum industry in Egypt. The aim of this work is to calculate the risk and dose assessment received from trench disposal facility directly and after closure (1000 year). RESRAD computer code was used. The results indicated that the total effective dose (TED) received after direct closure of trench disposal facility was 7.7E-4 mSv/y while after 1000 years, it will he 3.4E-4. The health cancer risk after direct closure was 3.3E-8 while after 1000 years post closure it was 6E-8. Results of this assessment will help examine policy issues concerning different options and regulation of NORM contaminated waste generated by petroleum industry

Performance Analysis of Trench Power MOSFETs in High-Frequency Synchronous Buck Converter Applications

Directory of Open Access Journals (Sweden)

Yali Xiong

2008-01-01

Full Text Available This paper investigates the performance perspectives and theoretical limitations of trench power MOSFETs in synchronous rectifier buck converters operating in the MHz frequency range. Several trench MOSFET technologies are studied using a mixed-mode device/circuit modeling approach. Individual power loss contributions from the control and synchronous MOSFETs, and their dependence on switching frequency between 500 kHz and 5 MHz are discussed in detail. It is observed that the conduction loss contribution decreases from 40% to 4% while the switching loss contribution increases from 60% to 96% as the switching frequency increases from 500 KHz to 5 MHz. Beyond 1 MHz frequency there is no obvious benefit to increase the die size of either SyncFET or CtrlFET. The RDS(ON×QG figure of merit (FOM still correlates well to the overall converter efficiency in the MHz frequency range. The efficiency of the hard switching buck topology is limited to 80% at 2 MHz and 65% at 5 MHz even with the most advanced trench MOSFET technologies.

Special Analysis: Updated Analysis of the Effect of Wood Products on Trench Disposal Limits at the E-Area Low-Level Waste Facility

International Nuclear Information System (INIS)

Cook, J.R.

2001-01-01

This Special Analysis (SA) develops revised radionuclide inventory limits for trench disposal of low-level radioactive waste in the presence of wood products in the E-Area Low-Level Waste Facility. These limits should be used to modify the Waste Acceptance Criteria (WAC) for trench disposal. Because the work on which this SA is based employed data from tests using 100 percent wood products, the 40 percent limitation on wood products for trench (i.e., slit or engineered trench) disposal is not needed in the modified WAC

Sulfate Deposition in Regolith Exposed in Trenches on the Plains Between the Spirit Landing Site and Columbia Hills in Gusev Crater, Mars

Science.gov (United States)

Wang, Alian; Haskin, L. A.; Squyres, S. W.; Arvidson, R.; Crumpler, L.; Gellert, R.; Hurowitz, J.; Schroeder, C.; Tosca, N.; Herkenhoff, K.

2005-01-01

During its exploration within Gusev crater between sol 01 and sol 158, the Spirit rover dug three trenches (Fig. 1) to expose the subsurface regolith [1, 2, 9]. Laguna trench (approx. 6 cm deep, approx.203 m from the rim of Bonneville crater) was dug in Laguna Hollow at the boundary of the impact ejecta from Bonneville crater and the surrounding plains. The Big Hole trench (approx. 6-7 cm deep) and The Boroughs trench (approx. 11 cm deep) were dug in the plains between the Bonneville crater and the Columbia Hills (approx.556 m and approx.1698 m from the rim of Bonneville crater respectively). The top, wall and floor regolith of the three trenches were investigated using the entire set of Athena scientific instruments [10].

Formation of metal and dielectric liners using a solution process for deep trench capacitors.

Science.gov (United States)

Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

2012-07-01

We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor.

Plastic pollution of the Kuril-Kamchatka Trench area (NW pacific)

Science.gov (United States)

Fischer, Viola; Elsner, Nikolaus O.; Brenke, Nils; Schwabe, Enrico; Brandt, Angelika

2015-01-01

During the German-Russian expedition KuramBio (Kuril-Kamchatka Biodiversity Studies) to the northwest Pacific Kuril-Kamchatka Trench and its adjacent abyssal plain, we found several kinds and sizes of plastic debris ranging from fishing nets and packaging to microplastic in the sediment of the deep-sea floor. Microplastics were ubiquitous in the smaller fractions of the box corer samples from every station from depths between 4869 and 5766 m. They were found on the abyssal plain and in the sediments of the trench slope on both sides. The amount of microplastics differed between the stations, with lowest concentration of 60 pieces per m2 and highest concentrations of more than 2000 pieces per m2. Around 75% of the microplastics (defined here as particles plastic debris we found, as a documentation of human impact into the deep sea of this region of the Northwest Pacific.

Preliminary Hazard Classification for the 116-N-3 Crib and Trench Remediation Activities

International Nuclear Information System (INIS)

Adam, W. J.

1999-01-01

The purpose of this document is to provide a preliminary hazard classification (PHC) for the remediation of the 116-N-3 crib and trench, also known as the 1325-N crib and trench, which are located within the 100-NR-1 Operable Unit of the Hanford Site's 100-N Area. In addition to the work scope described below, current planning also includes removal of some of the pipelines located downstream from the 13 15-N valve box and sampling of other pipelines to determine if remedial actions goals have been met and the pipelines can be left in place

Electrokinetic migration studies on removal of chromium and uranyl ions from 904-A trench soil

International Nuclear Information System (INIS)

Bibler, J.P.; Meaker, T.F.; O'Steen, A.B.

1992-01-01

This report describes a laboratory-scale study, in which electrokinetic migration technology was used to remove chromium and uranium, as well as other ions, from soil taken from a bore hole adjacent to the 904-A trench at the Savannah River Technology Center. Imposition of an electric current on humid (not saturated) soil successfully caused cations to migrate through the pore water of the soil to the cathode, where they were captured in an ISOLOCKTm polymer matrix and in a cation exchange resin incorporated in the polymer. Chemicals circulated through the anode/polymer and cathode/polymer were able to control pH excursions in the electrokinetic-cells by reacting with the H + and OH - generated at the anode and cathode, respectively. The study indicates that ions adsorbed on the surface of the soil as well as those in the pores of soil particles can be caused to migrate through the soil to an appropriate electrode. After 10 days of operation at 20--25 V and 2 mA, approximately 65% of the chromium was removed from two 3.5 kg soil samples. A 57% removal of uranium was achieved. The study shows that electrokinetic migration, using the ISOLOCK trademark polymer will be effective as an in situ treatment method for the removal of metal ion contaminants in soil adjacent to the 904-A trench

Permeability of covers over low-level radioactive-waste burial trenches, West Valley, Cattaraugus County, New York. Water resources investigations (final) 1977-78

International Nuclear Information System (INIS)

Prudic, D.E.

1980-09-01

Gas pressure in the unsaturated parts of radioactive waste burial trenches responds to fluctuations in atmospheric pressure. Measurements of atmospheric pressure and the differential pressure between the trench gas and the atmosphere on several dates in 1977-78 were used to calculate hydraulic conductivity of the reworked silty-clay till that covers the trenches. Generally the hydraulic conductivity of covers over trenches that had a history of rapidly rising water levels are higher, at least seasonally, than covers over trenches in which the water level remained low. This supports the hypothesis that recharge occurs through the cover, presumably through fractures caused by desiccation and (or) subsidence. Hydraulic conductivities of the cover as calculated from gas- and air-pressure measurements at several trenches were 100 to 1,000 times greater than those calculated from the increase in water levels in the trenches. This difference suggests that the values obtained from the air- and gas-pressure measurements need to be adjusted and at present are not directly usable in ground-water flux calculations. The difference in magnitude of values may be caused by rapidly decreasing hydraulic conductivity during periods of recharge or by the clogging of fractures with sediment washed in by runoff

PROJECT-SPECIFIC TYPE A VERIFICATION FOR THE HIGH FLUX BEAM REACTOR UNDERGROUND UTILITIES REMOVAL PHASE 3 TRENCH 5, BROOKHAVEN NATIONAL LABORATORY UPTON, NEW YORK

International Nuclear Information System (INIS)

Weaver, P.C.

2010-01-01

The Oak Ridge Institute for Science and Education (ORISE) has reviewed the project documentation and data for the High Flux Beam Reactor (HFBR) Underground Utilities removal Phase 3; Trench 5 at Brookhaven National Laboratory (BNL) in Upton, New York. The Brookhaven Survey Group (BSG) has completed removal and performed Final Status Survey (FSS) of the concrete duct from Trench 5 from Building 801 to the Stack. Sample results have been submitted as required to demonstrate that the cleanup goal of (le)15 mrem/yr above background to a resident in 50 years has been met. Four rounds of sampling, from pre-excavation to FSS, were performed as specified in the Field Sampling Plan (FSP) (BNL 2010a). It is the policy of the U.S. Department of Energy (DOE) to perform independent verifications of decontamination and decommissioning activities conducted at DOE facilities. ORISE has been designated as the organization responsible for this task for the HFBR Underground Utilities. ORISE, together with DOE, determined that a Type A verification of Trench 5 was appropriate based on recent verification results from Trenches 2, 3, and 4, and the minimal potential for residual radioactivity in the area. The removal of underground utilities is being performed in three stages to decommission the HFBR facility and support structures. Phase 3 of this project included the removal of at least 200 feet of 36-inch to 42-inch pipe from the west side to the south side of Building 801, and the 14-inch diameter Acid Waste Line that spanned from 801 to the Stack within Trench 5. Based on the pre-excavation sample results of the soil overburden the potential for contamination of the soil surrounding the pipe is minimal (BNL 2010a). ORISE reviewed the BNL FSP and identified comments for consideration (ORISE 2010). BNL prepared a revised FSP that resolved each ORISE comment adequately (BNL 2010a). ORISE referred to the revised HFBR Underground Utilities FSP FSS data to conduct the Type A verification

Radiation-enhanced short channel effects due to multi-dimensional influence from charge at trench isolation oxides

International Nuclear Information System (INIS)

Youk, G.U.; Khare, P.S.; Schrimpf, R.D.; Massengill, L.W.; Galloway, K.F.

1999-01-01

Radiation enhanced drain induced barrier lowering (DIBL) was experimentally observed and verified by 3-D simulations for submicron devices with trench isolation oxides. Submicron MOSFETs with shallow trench isolation were exposed to total-ionizing-dose radiation. Prior to irradiation, the devices exhibited near-ideal current-voltage characteristics, with no significant short-channel effects for as-drawn gate lengths of 0.4 microm. Following irradiation, the off-state leakage current increased significantly for total doses above about 650 krad(SiO 2 ). In addition, the irradiated devices exhibited DIBL that increased the drain current by 5--10x for a gate length of 0.4 microm (the nominal minimum gate length for this process) and much more for slightly shorter devices (0.35 microm). The increase in the off-state leakage current and the accompanying DIBL are shown to be associated with a parasitic field-effect transistor that is present at the edge of the shallow trench. Three-dimensional simulations are used to illustrate the effect. Simulations show that trapped charge at the trench sidewalls enhance the DIBL by depleting the edges of the channel. Radiation-induced charge may decrease the effectiveness of short-channel engineering

Remedial action planning for Trench 1

International Nuclear Information System (INIS)

Primrose, A.; Sproles, W.; Burmeister, M.; Wagner, R.; Law, J.; Greengard, T.; Castaneda, N.

1998-01-01

The accelerated action to remove the depleted uranium chips and associated soils and wastes from Trench 1 at the Rocky Flats Environmental Technology Site (RFETS) will begin in June 1998. To ensure that the remedial action is conducted safely, a rigorous and disciplined planning process was followed that incorporates the principles of Integrated Safety Management and Enhanced Work Planning. Critical to the success of the planning was early involvement of project staff (salaried and hourly) and associated technical support groups and disciplines. Feedback was and will continue to be solicited, and lessons learned incorporated to ensure the safe remediation of this site

Monitored Retrievable Storage conceptual system study: cask-in-trench

International Nuclear Information System (INIS)

1983-11-01

This report provides a description of the Cask-in-Trench Storage Concept which meets a specified set of requirements; an estimate of the costs of construction, operation and decommissioning of the concept; the costs required to expand the facility throughput and storage capability; and the life cycle costs of the facility. 22 figures, 34 tables

The Incident in Trench A - Follow-up and Lessons

CERN Multimedia

Olga Beltramello; Peter Jenni

An incident happened on 12th October during the dismounting of the HF truck platform in Trench A in the ATLAS cavern. Nobody was injured or in direct danger to be hurt, thanks in particular to the vigilance of the lifting operation crew. However, there is ample matter to reflect upon, and to recall safety measures applicable at any time in the cavern. What happened? During the lifting operation of a lateral platform from the orange HF Truck, used for example for the calorimeter assembly, one of the ~7 m long pillars fell on the access stairs into the ATLAS detector (sector 13). The standard operation to dismount the platform consisted in first unbolting the platform from its support pillars and removing it. Then, after securing a given pillar with the crane, this pillar is unbolted from the floor and removed. By mistake, this pillar was not bolted onto the floor, and fell when the platform was removed. Nobody was present in the trench during the lifting operation and the fall of the pillar. The contractor in...

Identification of Free-living and Particle-Associated Microbial Communities Present in Hadal regions of the Mariana Trench

Directory of Open Access Journals (Sweden)

Jonathan eTarn

2016-05-01

Full Text Available Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs and the Sirena Deep (10,667 mbs within the Mariana Trench, as well as one control site (Ulithi Atoll, 761 mbs. Seawater samples were collected using an autonomous lander positioned ~1m above the seafloor. The bacterial populations within the Mariana Trench bottom water samples were dissimilar to other deep-sea microbial communities, though with overlap with those of diffuse flow hydrothermal vents and deep-subsurface locations. Distinct particle-associated and free-living bacterial communities were found to exist. The hadal bacterial populations were also markedly different from one another, indicating the likelihood of different chemical conditions at the two sites. In contrast to the bacteria, the hadal archaeal communities were more similar to other less deep datasets and to each other due to an abundance of cosmopolitan deep-sea taxa. The hadal communities were enriched in thirty four bacterial and four archaeal operational taxonomic units (OTUs including members of the Gammaproteobacteria, Epsilonproteobacteria, Marinimicrobia, Cyanobacteria, Deltaproteobacteria, Gemmatimonadetes, Atribacteria, Spirochaetes, and Euryarchaeota. Sequences matching cultivated piezophiles were notably enriched in the Challenger Deep, especially within the particle-associated fraction, and were found in higher abundances than in other hadal studies, where they were either far less prevalent or missing. Our results indicate the importance of heterotrophy, sulfur-cycling, and methane and hydrogen utilization within the bottom waters of the deeper

Identification of Free-Living and Particle-Associated Microbial Communities Present in Hadal Regions of the Mariana Trench.

Science.gov (United States)

Tarn, Jonathan; Peoples, Logan M; Hardy, Kevin; Cameron, James; Bartlett, Douglas H

2016-01-01

Relatively few studies have described the microbial populations present in ultra-deep hadal environments, largely as a result of difficulties associated with sampling. Here we report Illumina-tag V6 16S rRNA sequence-based analyses of the free-living and particle-associated microbial communities recovered from locations within two of the deepest hadal sites on Earth, the Challenger Deep (10,918 meters below surface-mbs) and the Sirena Deep (10,667 mbs) within the Mariana Trench, as well as one control site (Ulithi Atoll, 761 mbs). Seawater samples were collected using an autonomous lander positioned ~1 m above the seafloor. The bacterial populations within the Mariana Trench bottom water samples were dissimilar to other deep-sea microbial communities, though with overlap with those of diffuse flow hydrothermal vents and deep-subsurface locations. Distinct particle-associated and free-living bacterial communities were found to exist. The hadal bacterial populations were also markedly different from one another, indicating the likelihood of different chemical conditions at the two sites. In contrast to the bacteria, the hadal archaeal communities were more similar to other less deep datasets and to each other due to an abundance of cosmopolitan deep-sea taxa. The hadal communities were enriched in 34 bacterial and 4 archaeal operational taxonomic units (OTUs) including members of the Gammaproteobacteria, Epsilonproteobacteria, Marinimicrobia, Cyanobacteria, Deltaproteobacteria, Gemmatimonadetes, Atribacteria, Spirochaetes, and Euryarchaeota. Sequences matching cultivated piezophiles were notably enriched in the Challenger Deep, especially within the particle-associated fraction, and were found in higher abundances than in other hadal studies, where they were either far less prevalent or missing. Our results indicate the importance of heterotrophy, sulfur-cycling, and methane and hydrogen utilization within the bottom waters of the deeper regions of the Mariana Trench

Corrective action decision document for the Roller Coaster Lagoons and North Disposal Trench (Corrective Action Unit Number 404)

International Nuclear Information System (INIS)

1997-01-01

The North Disposal Trench, located north of the eastern most lagoon, was installed in 1963 to receive solid waste and construction debris from the Operation Roller Coaster man camp. Subsequent to Operation Roller Coaster, the trench continued to receive construction debris and range cleanup debris (including ordnance) from Sandia National Laboratories and other operators. A small hydrocarbon spill occurred during Voluntary Corrective Action (VCA) activities (VCA Spill Area) at an area associated with the North Disposal Trench Corrective Action Site (CAS). Remediation activities at this site were conducted in 1995. A corrective action investigation was conducted in September of 1996 following the Corrective Action Investigation Plan (CAIP); the detailed results of that investigation are presented in Appendix A. The Roller Coaster Lagoons and North Disposal Trench are located at the Tonopah Test Range (TTR), a part of the Nellis Air Force Range, which is approximately 225 kilometers (140 miles) northwest of Las Vegas, Nevada, by air

A New and Simple Method for Crosstalk Estimation in Homogeneous Trench-Assisted Multi-Core Fibers

DEFF Research Database (Denmark)

Ye, Feihong; Tu, Jiajing; Saitoh, Kunimasa

2014-01-01

A new and simple method for inter-core crosstalk estimation in homogeneous trench-assisted multi-core fibers is presented. The crosstalk calculated by this method agrees well with experimental measurement data for two kinds of fabricated 12-core fibers.......A new and simple method for inter-core crosstalk estimation in homogeneous trench-assisted multi-core fibers is presented. The crosstalk calculated by this method agrees well with experimental measurement data for two kinds of fabricated 12-core fibers....

Geological mapping of investigation trench OL-TK19 at the Olkiluoto study site, Eurajoki, SW Finland

Energy Technology Data Exchange (ETDEWEB)

Eroma, E.; Nordbaeck, N.; Engstroem, J. [Geological Survey of Finland, Espoo (Finland)

2014-12-15

In October 2012, the geological mapping of investigation trench OL-TK19 was carried out by the Geological Survey of Finland at the Olkiluoto study site. The SE-NW trending, ca. 85 m long trench is located in the central part of the Olkiluoto Island next to investigation trenches OL-TK18 and OL-TK4. The lithology in investigation trench OL-TK19 is of heterogeneous character, with rock type varying from veined gneiss, diatexitic gneiss to pegmatitic granite, along with portions of mica gneiss and K-feldspar porphyritic gneiss. In addition, inclusions of mica gneiss, quartz gneiss and skarn are encountered. The rocks have been subjected to a multiphase ductile deformation and the trench is situated in an area where the latest ductile deformation phase, D4 prevails. The investigation trench can be divided into three domains according to its dominant deformation phase and foliation; the eastern part of the trench is dominated by the D3 deformation phase whereas the middle and western parts are dominated by the D4 deformation phase. The S3 foliation has a more ENE-WSW oriented direction whereas the S4 is trending NE-SW. In addition to this difference in orientation, the different structural signature of these two deformation types is observed, the S3 foliation is defined by smaller scaled granitic leucosome veining whereas the S4 foliation is intensely sheared and have a schistose character. During the fracture mapping, all fractures intersecting the central thread were investigated and a total of 132 fractures were recorded. The average fracture frequency 1.53 fractures/m. On the basis of fracture orientations, three fracture sets can be defined. The first set is vertical and NW-SE trending, second set strikes NE-SW with a moderate dip towards the SE and the third set is vertical and NE-SW trending. The median fracture length is 1.38 m and most fractures do not exceed 0.5 m in length, the longest measured fracture being 5.30 m in length. Fracture fillings are mostly

An electrostatic 3-phase linear stepper motor fabricated by vertical trench isolation technology

International Nuclear Information System (INIS)

Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Fujita, Hiroyuki

2009-01-01

We present the design, microfabrication and characterization of an electrostatic 3-phase linear stepper micromotor constructed with vertical trench isolation technology. This suitable technology was used to create a monolithic stepper motor with high-aspect-ratio poles and an integrated 3-phase electrical network in the bulk of a standard single-crystal silicon wafer. The shuttle of the stepper motor is suspended by a flexure to avoid any mechanical contact during operation, enhancing the precision, repeatability and reliability of the stepping motion. The prototype is capable of a maximum travel of +/−26 µm (52 µm) at an actuation voltage of 30 V and a step size of 1.4 µm during a half-stepping sequence

Task plan to evaluate the effectiveness of in situ grouting of an ORNL waste burial trench with a cement-based grout

International Nuclear Information System (INIS)

Francis, C.W.

1991-11-01

This task will demonstrate the feasibility of using an in situ grouting technique with a particulate-grout formulation as a closure action to stabilize waste trenches in Solid Waste Storage Area (SWSA) 6. It also supports technology development for closure of other SWSAs. A particulate grout will be formulated using cement-bentonite and fly ash from a coal-fired power plant. The grout solids will be dry-blended, mixed with water, and injected (using ∼5 to 10 lb/in. 2 pressure) into five injection wells per trench. After 28 days for setting, soil penetration resistance and hydraulic conductivity measurements will be repeated for comparison to pregrouting measurements. The primary objective of this task is to demonstrate the feasibility and effectiveness of the in situ injection of a particulate grout into waste burial trenches. Effectiveness is defined here as increased trenched stability (characterized by trench penetration resistance tests) and decreased potential for leachate migration (characterized by hydraulic conductivity tests)

Interim safety basis compliance matrix for Trenches 31 and 34

International Nuclear Information System (INIS)

Ames, R.R.

1994-01-01

The tables provided in this document identify the specific requirements and basis for the administrative controls established in the Westinghouse Hanford Company (WHC) Solid Waste Burial Ground (SWBG) Interim Safety Basis (ISB) for operation of the Project W-025, Mixed Waste Lined Landfill (Trenches 31 and 34). The tables document the necessary controls and implementing procedures to ensure compliance with the requirements of the ISB. These requirements provide a basis for future Unreviewed Safety Questions (USQ) screening of applicable procedure changes, proposed physical modifications, tests, experiments, and occurrences. Table 1 provides the SWBG interim Operational Safety Requirements administrative controls matrix. The specific assumptions and commitments used in the safety analysis documents applicable to disposal of mixed wastes in Trenches 31 and 34 are provided in Table 2. Table 3 is provided to document the potential engineered and administrative mitigating features identified in the Preliminary Hazard Analysis (PHA) for disposal of mixed waste

Single-crystal silicon trench etching for fabrication of highly integrated circuits

Science.gov (United States)

Engelhardt, Manfred

1991-03-01

The development of single crystal silicon trench etching for fabrication of memory cells in 4 16 and 64Mbit DRAMs is reviewed in this paper. A variety of both etch tools and process gases used for the process development is discussed since both equipment and etch chemistry had to be improved and changed respectively to meet the increasing requirements for high fidelity pattern transfer with increasing degree of integration. In additon to DRAM cell structures etch results for deep trench isolation in advanced bipolar ICs and ASICs are presented for these applications grooves were etched into silicon through a highly doped buried layer and at the borderline of adjacent p- and n-well areas respectively. Shallow trench etching of large and small exposed areas with identical etch rates is presented as an approach to replace standard LOCOS isolation by an advanced isolation technique. The etch profiles were investigated with SEM TEM and AES to get information on contathination and damage levels and on the mechanism leading to anisotropy in the dry etch process. Thermal wave measurements were performed on processed single crystal silicon substrates for a fast evaluation of the process with respect to plasma-induced substrate degradation. This useful technique allows an optimization ofthe etch process regarding high electrical performance of the fully processed memory chip. The benefits of the use of magnetic fields for the development of innovative single crystal silicon dry

3D electrical method and step continuous wave radar method for Nojima site. Results of measurement of resistivity at trench site; Nojima danso ni okeru sanjigenhi teikoho to step shiki renzokuha chika radar ho tansa. Trench chosa chiten deno hiteiko sokutei kekka

Energy Technology Data Exchange (ETDEWEB)

Suzuki, K; Oda, Y; Tank, K [Central Research Institute of Electric Power Industry, Tokyo (Japan); Hayashi, H [Kawasaki Geological Engineering Co. Ltd., Tokyo (Japan); Jomori, A [Japan Crust Research, Tokyo (Japan)

1996-05-01

Several surveys were carried out near the Nojima fault, including three-dimensional resistivity measurement and underground radar survey at the Ogura area, underground radar survey at the Hirabayashi area, and resistivity measurement in the vicinity of the trench at the Nashinomoto area, in order to investigate in detail the underground structures at a depth up to several tens meters from the ground surface. Resistivity was measured by an automatic analyzer capable of simultaneously measuring potential levels at 14 channels which can cover 112 measuring points at the largest. At the Ogura area, the boundary planes of the resistivity structures are continuously detected in the direction of the fault moving during the earthquake period. The underground radar measurement results suggest accumulated displacement of strata at a depth of around 25m in the Osaka Strata and flexible structures. At the Hirabayashi area, the underground radar analysis detects discrete sections in the reflection planes at the fault position, but no reflection planes of high continuity. At the Nashinomoto area, the clay stratum detected in the fault by excavating the trenches are found to be low in resistivity by the resistivity measurement. 4 refs., 11 figs., 2 tabs.

Sensor assembly method using silicon interposer with trenches for three-dimensional binocular range sensors

Science.gov (United States)

Nakajima, Kazuhiro; Yamamoto, Yuji; Arima, Yutaka

2018-04-01

To easily assemble a three-dimensional binocular range sensor, we devised an alignment method for two image sensors using a silicon interposer with trenches. The trenches were formed using deep reactive ion etching (RIE) equipment. We produced a three-dimensional (3D) range sensor using the method and experimentally confirmed that sufficient alignment accuracy was realized. It was confirmed that the alignment accuracy of the two image sensors when using the proposed method is more than twice that of the alignment assembly method on a conventional board. In addition, as a result of evaluating the deterioration of the detection performance caused by the alignment accuracy, it was confirmed that the vertical deviation between the corresponding pixels in the two image sensors is substantially proportional to the decrease in detection performance. Therefore, we confirmed that the proposed method can realize more than twice the detection performance of the conventional method. Through these evaluations, the effectiveness of the 3D binocular range sensor aligned by the silicon interposer with the trenches was confirmed.

ALGORITHM OF DETERMINATION OF POWER AND ENERGY INDEXES OF SCREW INTENSIFIER ON THE BULLDOZER WORKING EQUIPMENT AT TRENCH REFILLINGS

Directory of Open Access Journals (Sweden)

KROL R. N.

2016-03-01

Full Text Available Raising of problem. A bulldozer work at trench refilings is conducted by cyclic, machine shuttle motions that increases a right-of-way; increasing of time charges, fuel and labour by the side of the continuous refilling method. Besides the indicated defects gets worse also the quality of the trench refilling: the uneven soil output into a trench with large portions results the damages of pipes isolation and emptinesses formation, in consequence  settling and washing of soil. A bulldozer with the screw intensifier (SI, is deprived lacks of an odinary bulldozer  moving along a trench, it moves the loose soil that does not fall on a pipeline, but rolles on it. Thus the circuitous speed of a cutting edge of SI exceeds the speed of the base machine moving that provides the strong soil treatment (before dispersion before output into a trench. Purpose. The algorithm development of the rotational moment determination on the SI driveshaft, the consumable energy, the energy intensity and the working process productivity of the reverse trench refillings depending on physical and mechanical properties of soil, geometrical parameters of SI and bulldozer optimal speed. Conclusion. The developed algorithm allows to define that at the fixed value of the rotational speed the rotational moment and indicated efficiency of SI at the optimum speed increasing of the base machine change on a linear law; the optimum speed change of the base machine practically does not influence on the energy intensity at the considered change of the rotational speed .

Changes in soil hydraulic properties caused by construction of a simulated waste trench at the Idaho National Engineering Laboratory, Idaho

International Nuclear Information System (INIS)

Shakofsky, S.

1995-03-01

In order to assess the effect of filled waste disposal trenches on transport-governing soil properties, comparisons were made between profiles of undisturbed soil and disturbed soil in a simulated waste trench. The changes in soil properties induced by the construction of a simulated waste trench were measured near the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory (INEL) in the semiarid southeast region of Idaho. The soil samples were collected, using a hydraulically-driven sampler to minimize sample disruption, from both a simulated waste trench and an undisturbed area nearby. Results show that the undisturbed profile has distinct layers whose properties differ significantly, whereas the soil profile in the simulated waste trench is, by comparison, homogeneous. Porosity was increased in the disturbed cores, and, correspondingly, saturated hydraulic conductivities were on average three times higher. With higher soil-moisture contents (greater than 0.32), unsaturated hydraulic conductivities for the undisturbed cores were typically greater than those for the disturbed cores. With lower moisture contents, most of the disturbed cores had greater hydraulic conductivities. The observed differences in hydraulic conductivities are interpreted and discussed as changes in the soil pore geometry

A Re-Os Study of Depleted Trench Peridotites from Northern Mariana

Science.gov (United States)

Ghosh, T.; Snow, J. E.; Heri, A. R.; Brandon, A. D.; Ishizuka, O.

2017-12-01

Trench peridotites provide information about the influence of subduction initiation on the extent of mantle wedge melting. They preserve melting records throughout subduction history, and as a result, likely experience multiple melt extraction events leading to successive depletion of melt/fluid mobile major and trace elements. To track melting histories of trench peridotites, Re-Os and PGEs can be used as reliable tracers to constrain early melt extraction or re-fertilization events. The Izu-Bonin-Mariana arc, being the largest intra-oceanic subduction system, provides an excellent area to study the formation of supra-subduction zone mantle and crust. Residual peridotite (harzburgite and dunite) samples were collected by dredging from the landward slope of the northern Mariana Trench. The samples are serpentinized to various extents (typical of abyssal peridotites), leaving behind relict grains of spinel, enstatite and olivine embedded within a serpentine matrix along with occasional interstitial diopside. Major element analyses of primary minerals reveal a wide range of variations in Cr# of spinels from 0.31-0.85 indicating 16-20% of melt fraction with dunites apparently experiencing the highest amount of partial melting. For Re-Os and PGE geochemistry, samples with high amounts of spinel (>4 vol %) and variable Cr# were chosen. Initial results show that bulk rock 187Os/188Os ratios range from 0.1113 to 0.1272. All of the samples are sub-chondritic, but in some cases, they are more radiogenic than average abyssal peridotites. Os abundances vary from 1-9 ppb. Sub-chondritic values can be attributed to the samples having evolved from a Re-depleted mantle source indicating a previous melt-extraction event. The cpx-harzburgites, having lower Cr# ( 0.4) are more radiogenic than ultra depleted dunites (Cr# 0.8), which might indicate preferential removal of Os during an apparent higher degree of partial melting experienced by dunites. The higher 187Os/188Os ratios of

X-ray-to-current signal conversion characteristics of trench-structured photodiodes for direct-conversion-type silicon X-ray sensor

International Nuclear Information System (INIS)

Ariyoshi, Tetsuya; Funaki, Shota; Sakamoto, Kenji; Baba, Akiyoshi; Arima, Yutaka

2017-01-01

To reduce the radiation dose required in medical X-ray diagnoses, we propose a high-sensitivity direct-conversion-type silicon X-ray sensor that uses trench-structured photodiodes. This sensor is advantageous in terms of its long device lifetime, noise immunity, and low power consumption because of its low bias voltage. With this sensor, it is possible to detect X-rays with almost 100% efficiency; sensitivity can therefore be improved by approximately 10 times when compared with conventional indirect-conversion-type sensors. In this study, a test chip was fabricated using a single-poly single-metal 0.35 μm process. The formed trench photodiodes for the X-ray sensor were approximately 170 and 300 μm deep. At a bias voltage of 25 V, the absorbed X-ray-to-current signal conversion efficiencies were 89.3% (theoretical limit; 96.7%) at a trench depth of 170 μm and 91.1% (theoretical limit; 94.3%) at a trench depth of 300 μm. (author)

P-wave Velocity Structure Across the Mariana Trench and Implications for Hydration

Science.gov (United States)

Eimer, M. O.; Wiens, D.; Lizarralde, D.; Cai, C.

2017-12-01

Estimates of the water flux at subduction zones remain uncertain, particularly the amount of water brought into the trench by the subducting plate. Normal faulting related to the bending of the incoming plate has been proposed to provide pathways for water to hydrate the crust and upper mantle. A passive and active source seismic experiment spanning both the incoming plate and forearc was conducted in 2012 in central Mariana to examine the role of hydration at subduction zones. The active-source component of the survey used the R/V M.G. Langsethairgun array and 68 short period sensors, including suspended hydrophones, deployed on 4 transects. This study at the Mariana trench offers a comparison to related studies of incoming plate hydration in Middle America, where differing thermal structures related to plate age predict different stability fields for hydrous minerals. The forearc structure is also of interest, since Mariana is characterized by large serpentine seamounts and may have a serpentinized mantle wedge. The velocity structure will also be important for the relocation of earthquakes in the incoming plate, since the seismicity can offer a constraint for the depth extent of these bending faults. We examine the P-wave velocity structure along a 400-km long wide-angle refraction transect perpendicular to the trench and spanning both the forearc and incoming plate. Preliminary results indicate a velocity reduction in the crust and uppermost mantle at the bending region of the incoming plate, relative to the plate's structure away from the trench. This reduction suggests that outer-rise faults extend into the upper mantle and may have promoted serpentinization of that material. Mantle Pn refraction phases are not observed in the forearc, consistent with the ambient noise tomography results that show upper-mantle velocities similar to that of the lower crust. The lack of contrast between the upper mantle and crustal velocities from the ambient noise has been

Convective mixing by internal waves in the Puerto Rico Trench

NARCIS (Netherlands)

van Haren, H.; Gostiaux, L.

2016-01-01

A2.4 km long deep-sea mooringwas deployed for 14 months in the Puerto Rico Trench, the deepestpart of the Atlantic Ocean. Below its top buoyancy package, the mooring line held a 200 m long stringof high-resolution temperature sensors and a current meter. Over the instrumented range between6,004 and

Bending-related faulting and mantle serpentinization at the Middle America trench.

Science.gov (United States)

Ranero, C R; Morgan, J Phipps; McIntosh, K; Reichert, C

2003-09-25

The dehydration of subducting oceanic crust and upper mantle has been inferred both to promote the partial melting leading to arc magmatism and to induce intraslab intermediate-depth earthquakes, at depths of 50-300 km. Yet there is still no consensus about how slab hydration occurs or where and how much chemically bound water is stored within the crust and mantle of the incoming plate. Here we document that bending-related faulting of the incoming plate at the Middle America trench creates a pervasive tectonic fabric that cuts across the crust, penetrating deep into the mantle. Faulting is active across the entire ocean trench slope, promoting hydration of the cold crust and upper mantle surrounding these deep active faults. The along-strike length and depth of penetration of these faults are also similar to the dimensions of the rupture area of intermediate-depth earthquakes.

A metallic buried interconnect process for through-wafer interconnection

International Nuclear Information System (INIS)

Ji, Chang-Hyeon; Herrault, Florian; Allen, Mark G

2008-01-01

In this paper, we present the design, fabrication process and experimental results of electroplated metal interconnects buried at the bottom of deep silicon trenches with vertical sidewalls. A manual spray-coating process along with a unique trench-formation process has been developed for the electroplating of a metal interconnection structure at the bottom surface of the deep trenches. The silicon etch process combines the isotropic dry etch process and conventional Bosch process to fabricate a deep trench with angled top-side edges and vertical sidewalls. The resulting trench structure, in contrast to the trenches fabricated by wet anisotropic etching, enables spray-coated photoresist patterning with good sidewall and top-side edge coverage while maintaining the ability to form a high-density array of deep trenches without excessive widening of the trench opening. A photoresist spray-coating process was developed and optimized for the formation of electroplating mold at the bottom of 300 µm deep trenches having vertical sidewalls. A diluted positive tone photoresist with relatively high solid content and multiple coating with baking between coating steps has been experimentally proven to provide high quality sidewall and edge coverage. To validate the buried interconnect approach, a three-dimensional daisy chain structure having a buried interconnect as the bottom connector and traces on the wafer surface as the top conductor has been designed and fabricated

Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs.

Directory of Open Access Journals (Sweden)

Sara Mechtensimer

Full Text Available Septic systems can be a potential source of phosphorus (P in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface and piezometers were installed in the groundwater (>300 cm below infiltrative surface to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE, soil-water, and groundwater samples were collected for 64 events (May 2012-Dec 2013 at 2 to 3 days (n = 13, weekly (n = 29, biweekly (n = 17, and monthly (n = 5 intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15. Samples were analyzed for total P (TP, orthophosphate-P (PO4-P, and other-P (TP-PO4-P. The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater.

Septic Systems Contribution to Phosphorus in Shallow Groundwater: Field-Scale Studies Using Conventional Drainfield Designs

Science.gov (United States)

Mechtensimer, Sara

2017-01-01

Septic systems can be a potential source of phosphorus (P) in groundwater and contribute to eutrophication in aquatic systems. Our objective was to investigate P transport from two conventional septic systems (drip dispersal and gravel trench) to shallow groundwater. Two new in-situ drainfields (6.1 m long by 0.61 m wide) with a 3.72 m2 infiltrative surface were constructed. The drip dispersal drainfield was constructed by placing 30.5 cm commercial sand on top of natural soil and the gravel trench drainfield was constructed by placing 30.5 cm of gravel on top of 30.5 cm commercial sand and natural soil. Suction cup lysimeters were installed in the drainfields (at 30.5, 61, 106.7 cm below infiltrative surface) and piezometers were installed in the groundwater (>300 cm below infiltrative surface) to capture P dynamics from the continuum of unsaturated to saturated zones in the septic systems. Septic tank effluent (STE), soil-water, and groundwater samples were collected for 64 events (May 2012–Dec 2013) at 2 to 3 days (n = 13), weekly (n = 29), biweekly (n = 17), and monthly (n = 5) intervals. One piezometer was installed up-gradient of the drainfields to monitor background groundwater (n = 15). Samples were analyzed for total P (TP), orthophosphate-P (PO4–P), and other–P (TP—PO4-P). The gravel trench drainfield removed significantly (p300 cm in the groundwater, both systems had similar TP reductions of >97%. After 18 months of STE application, there was no significant increase in groundwater TP concentrations in both systems. We conclude that both drainfield designs are effective at reducing P transport to shallow groundwater. PMID:28107505

Oceanographic cruise Indian Ocean and Java Trench June 1969 (NODC Accession 7100908)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard H.M.A.S DIAMANTINA during an oceanographic cruise in the Java Trench and the Indian Ocean during...

THE PRODUCT DESIGN PROCESS USING STYLISTIC SURFACES

Directory of Open Access Journals (Sweden)

Arkadiusz Gita

2017-06-01

Full Text Available The increasing consumer requirements for the way what everyday use products look like, forces manufacturers to put more emphasis on product design. Constructors, apart from the functional aspects of the parts created, are forced to pay attention to the aesthetic aspects. Software for designing A-class surfaces is very helpful in this case. Extensive quality analysis modules facilitate the work and allow getting models with specific visual features. The authors present a design process of the product using stylistic surfaces based on the front panel of the moped casing. In addition, methods of analysis of the design surface and product technology are presented.

Effect of soil erosion on the long-term stability of FUSRAP near-surface waste-burial sites

International Nuclear Information System (INIS)

Knight, M.J.

1983-04-01

Decontamination of FUSRAP sites could result in the generation of large volumes (in excess of 400,000 m 3 ) of low-activity radioactive wastes (primarily contaminated soil and building materials) requiring subsequent disposal. It is likely that near-surface burial will be seriously considered as an option for disposal of these materials. A number of factors - including soil erosion - could adversely affect the long-term stability of a near-surface waste-burial site. The majority of FUSRAP sites are located in the humid eastern United States, where the principal cause of erosion is the action of water. This report examines the effect of soil erosion by water on burial-site stability based on analysis of four hypothetical near-surface burial sites. The Universal Soil Loss Equation was employed to estimate average annual soil loss from burial sites and the 1000-year effects of soil loss on the soil barrier (burial trench cap) placed over low-activity wastes. Results suggest that the land use of the burial site and the slope gradient of the burial trench cap significantly affect the rate of soil erosion. The development of measures limiting the potential land use of a burial site (e.g., mixing large rocks into the burial trench cap) may be required to preserve the integrity of a burial trench for long periods of time

Statistical analyses of in-situ and soil-sample measurements for radionuclides in surface soil near the 116-K-2 trench

International Nuclear Information System (INIS)

Gilbert, R.O.; Klover, W.J.

1988-09-01

Radiation detection surveys are used at the US Department of Energy's Hanford Reservation near Richland, Washington, to determine areas that need posting as radiation zones or to measure dose rates in the field. The relationship between measurements made by Sodium Iodide (NaI) detectors mounted on the mobile Road Monitor vehicle and those made by hand-held GM P-11 probes and Micro-R meters are of particular interest because the Road Monitor can survey land areas in much less time than hand-held detectors. Statistical regression methods are used here to develop simple equations to predict GM P-11 probe gross gamma count-per-minute (cpm) and Micro-R-Meter μR/h measurements on the basis of NaI gross gamma count-per-second (cps) measurements obtained using the Road Monitor. These equations were estimated using data collected near the 116-K-2 Trench in the 100-K area on the Hanford Reservation. Equations are also obtained for estimating upper and lower limits within which the GM P-11 or Micro-R-Meter measurement corresponding to a given NaI Road Monitor measurement at a new location is expected to fall with high probability. An equation and limits for predicting GM P-11 measurements on the basis of Micro-R- Meter measurements is also estimated. Also, we estimate an equation that may be useful for approximating the 90 Sr measurement of a surface soil sample on the basis of a spectroscopy measurement for 137 Cs on that sample. 3 refs., 16 figs., 44 tabs

Interim-status groundwater monitoring plan for the 216-B-63 trench

Energy Technology Data Exchange (ETDEWEB)

Sweeney, M.D.

1995-02-09

This document outlines the groundwater monitoring plan, under RCRA regulations in 40 CFR 265 Subpart F and WAC173-300-400, for the 216-B-63 Trench. This interim status facility is being sampled under detection monitoring criteria and this plan provides current program conditions and requirements.

Conductive Oxides Trench Structures as Hyperbolic Metamaterials in Mid-infrared Range

DEFF Research Database (Denmark)

Takayama, Osamu; Shkondin, Evgeniy; Panah, Mohammad Esmail Aryaee

,2]. Moreover plasmonics for mid-infrared offer unique applications such as bio-sensing, thermal imaging and quest for novel materials and structures has been continuing [3]. In this report we show that vertical trench structures made of, for example, aluminum-doped ZnO (AZO) or other transparent conductive...

Designing visual appearance using a structured surface

DEFF Research Database (Denmark)

Johansen, Villads Egede; Thamdrup, Lasse Højlund; Smitrup, Christian

2015-01-01

followed by numerical and experimental verification. The approach comprises verifying all design and fabrication steps required to produce a desired appearance. We expect that the procedure in the future will yield structurally colored surfaces with appealing prescribed visual appearances.......We present an approach for designing nanostructured surfaces with prescribed visual appearances, starting at design analysis and ending with a fabricated sample. The method is applied to a silicon wafer structured using deep ultraviolet lithography and dry etching and includes preliminary design...

Detection of norovirus virus-like particles using a surface plasmon resonance-assisted fluoroimmunosensor optimized for quantum dot fluorescent labels.

Science.gov (United States)

Ashiba, Hiroki; Sugiyama, Yuki; Wang, Xiaomin; Shirato, Haruko; Higo-Moriguchi, Kyoko; Taniguchi, Koki; Ohki, Yoshimichi; Fujimaki, Makoto

2017-07-15

A highly sensitive biosensor to detect norovirus in environment is desired to prevent the spread of infection. In this study, we investigated a design of surface plasmon resonance (SPR)-assisted fluoroimmunosensor to increase its sensitivity and performed detection of norovirus virus-like particles (VLPs). A quantum dot fluorescent dye was employed because of its large Stokes shift. The sensor design was optimized for the CdSe-ZnS-based quantum dots. The optimal design was applied to a simple SPR-assisted fluoroimmunosensor that uses a sensor chip equipped with a V-shaped trench. Excitation efficiency of the quantum dots, degree of electric field enhancement by SPR, and intensity of autofluorescence of a substrate of the sensor chip were theoretically and experimentally evaluated to maximize the signal-to-noise ratio. As the result, an excitation wavelength of 390nm was selected to excite SPR on an Al film of the sensor chip. The sandwich assay of norovirus VLPs was performed using the designed sensor. Minimum detectable concentration of 0.01ng/mL, which corresponds to 100 virus-like particles included in the detection region of the V-trench, was demonstrated. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

International Nuclear Information System (INIS)

Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

2009-01-01

This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC 'ground truthing' exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity 'target' in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical resistivity

Electrical Resistivity Correlation to Vadose Zone Sediment and Pore-Water Composition for the BC Cribs and Trenches Area

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Ward, Anderson L.; Um, Wooyong; Bjornstad, Bruce N.; Rucker, Dale F.; Lanigan, David C.; Benecke, Mark W.

2009-06-01

This technical report documents the results of geochemical and soil resistivity characterization of sediment obtained from four boreholes drilled in the BC Cribs and Trench area. Vadose zone sediment samples were obtained at a frequency of about every 2.5 ft from approximately 5 ft bgs to borehole total depth. In total, 505 grab samples and 39 six-inch long cores were obtained for characterization. The pore-water chemical composition data, laboratory-scale soil resistivity and other ancillary physical and hydrologic measurements and analyses described in this report are designed to provide a crucial link between direct measurements on sediments and the surface-based electrical-resistivity information obtained via field surveys. A second goal of the sediment characterization was to measure the total and water-leachable concentrations of key contaminants of concern as a function of depth and distance from the footprints of inactive disposal facilities. The total and water-leachable concentrations of key contaminants will be used to update contaminant distribution conceptual models and to provide more data for improving base-line risk predictions and remedial alternative selections. The ERC “ground truthing” exercise for the individual boreholes showed mixed results. In general, the high concentrations of dissolved salts in the pore waters of sediments from C5923, C5924 and C4191 produced a low resistivity “target” in the processed resistivity field surveys, and variability could be seen in the resistivity data that could relate to the variability in pore- water concentrations but the correlations (regression R2 were mediocre ranging from 0.2 to 0.7 at best; where perfect correlation is 1.0). The field-based geophysical data also seemed to suffer from a sort of vertigo, where looking down from the ground surface, the target (e.g., maximum pore-water salt concentration) depth was difficult to resolve. The best correlations between the field electrical

POST-CLOSURE INSPECTION AND MONITORING REPORT FOR CORRECTIVE ACTION UNIT 112: AREA 23 HAZARDOUS WASTE TRENCHES, NEVADA TEST SITE, NEVADA; FOR THE PERIOD OCTOBER 2003 - SEPTEMBER 2004

International Nuclear Information System (INIS)

BECHTEL NEVADA

2004-01-01

beneath each trench. Soil moisture results obtained to date indicate that the compliance criterion of less than 5% Residual Volumetric Moisture Content was met. Soil conditions remain dry and stable beneath the trenches, and the cover is functioning as designed within the compliance limits

Evaluation of dynamic compaction of low level waste burial trenches containing B-25 boxes

International Nuclear Information System (INIS)

McMullin, S.R.

1994-01-01

The Savannah River Site, owned by the US Department of Energy, is preparing to close an additional 13.8 ha of burial grounds under the Resource Conservation Recovery Act. In preparation for this closure, the dynamic compaction facility was designed and constructed to address unresolved design issues. Among these issues is the evaluation of the ability for dynamic compaction to consolidate buried low level waste containers. A model burial trench containing simulated clean wastes was dynamically compacted, after which the materials were excavated and compaction quantified. The test determined that under existing success criteria, the bottom tier of stacked B-25 boxes were not being consolidated. A quasi-structural layer was formed midway through the stacked boxes, which absorbed the compactive energy. Resulting from these observations and the data collected, a new success criterion is recommended which depends on the relative displacement per drop. The test successfully demonstrated that dynamic compaction will consolidate buried metal boxes

Source of high tsunamis along the southernmost Ryukyu trench inferred from tsunami stratigraphy

Science.gov (United States)

Ando, Masataka; Kitamura, Akihisa; Tu, Yoko; Ohashi, Yoko; Imai, Takafumi; Nakamura, Mamoru; Ikuta, Ryoya; Miyairi, Yosuke; Yokoyama, Yusuke; Shishikura, Masanobu

2018-01-01

Four paleotsunamis deposits are exposed in a trench on the coastal lowland north of the southern Ryukyu subduction zone trench. Radiocarbon ages on coral and bivalve shells show that the four deposits record tsunamis date from the last 2000 yrs., including a historical tsunami with a maximum run-up of 30 m in 1771, for an average recurrence interval of approximately 600 yrs. Ground fissures in a soil beneath the 1771 tsunami deposit may have been generated by stronger shaking than recorded by historical documents. The repeated occurrence of the paleotsunami deposits supports a tectonic source model on the plate boundary rather than a nontectonic source model, such as submarine landslides. Assuming a thrust model at the subduction zone, the seismic coupling ratio may be as low as 20%.

Determining RUSLE P-factors for stonebunds and trenches in rangeland and cropland, Northern Ethiopia

Science.gov (United States)

Taye, Gebeyehu; Poesen, Jean; Vanmaercke, Matthias; Van Wesemael, Bas; Tesfay, Samuel; Teka, Daniel; Nyssen, Jan; Deckers, Jozef; Haregeweyn, Nigussie

2017-04-01

The implementation of soil and water conservation (SWC) measures in the Ethiopian highlands is a top priority to reduce soil erosion rates and to enhance the sustainability of agroecosystem. Nonetheless, the effectiveness of many of these measures for different hillslope and land use conditions remains currently poorly understood. As a result, the overall effects of these measures at regional or catchment scale remain hard to quantify. This study addresses this knowledge gap by determining the cover-management (C) and support practice (P) factors of the Revised Universal Soil Loss Equation (RUSLE), for commonly used SWC measures in semi-arid environments (i.e. stone bunds, trenches and a combination of both). Calculations were based on soil loss data collected with runoff plots in Tigray, northern Ethiopia (i.e. 21 runoff plots of 600 to 1000 m2, monitored during 2010, 2011 and 2012). The runoff plots were installed in rangeland and cropland sites corresponding to a gentle (5%), medium (12%) and steep (16%) slope gradients. The C and P factors of the RUSLE were calculated following the recommended standard procedures. Results show that the C-factor for rangeland ranges from 0.31 to 0.98 and from 0.06 to 0.39 for cropland. For rangeland, this large variability is due to variations in vegetation cover caused by grazing. In cropland, C-factors vary with tillage practices and crop types. The calculated P-factors ranged from 0.32 to 0.74 for stone bunds, from 0.07 to 0.65 for trenches and from 0.03 to 0.22 for a combination of both stone bunds and trenches. This variability is partly due to variations in the density of the implemented measures in relation to land use (cropland vs rangeland) and slope angles. However, also annual variations in P factor values are highly significant. Especially trenches showed a very significant decline of effectiveness over time, which is attributable to their reduced static storage capacity as a result of sediment deposition (e.g. for

Corrective Action Investigation Plan for Corrective Action Unit 410: Waste Disposal Trenches, Tonopah Test Range, Nevada, Revision No.:0

International Nuclear Information System (INIS)

2002-01-01

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 410 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 410 is located on the Tonopah Test Range (TTR), which is included in the Nevada Test and Training Range (formerly the Nellis Air Force Range) approximately 140 miles northwest of Las Vegas, Nevada. This CAU is comprised of five Corrective Action Sites (CASs): TA-19-002-TAB2, Debris Mound; TA-21-003-TANL, Disposal Trench; TA-21-002-TAAL, Disposal Trench; 09-21-001-TA09, Disposal Trenches; 03-19-001, Waste Disposal Site. This CAU is being investigated because contaminants may be present in concentrations that could potentially pose a threat to human health and/or the environment, and waste may have been disposed of with out appropriate controls. Four out of five of these CASs are the result of weapons testing and disposal activities at the TTR, and they are grouped together for site closure based on the similarity of the sites (waste disposal sites and trenches). The fifth CAS, CAS 03-19-001, is a hydrocarbon spill related to activities in the area. This site is grouped with this CAU because of the location (TTR). Based on historical documentation and process know-ledge, vertical and lateral migration routes are possible for all CASs. Migration of contaminants may have occurred through transport by infiltration of precipitation through surface soil which serves as a driving force for downward migration of contaminants. Land-use scenarios limit future use of these CASs to industrial activities. The suspected contaminants of potential concern which have been identified are volatile organic compounds; semivolatile organic compounds; high explosives; radiological constituents including depleted uranium

Surface water management: a user's guide to calculate a water balance using the CREAMS model

International Nuclear Information System (INIS)

Lane, L.J.

1984-11-01

The hydrologic component of the CREAMS model is described and discussed in terms of calculating a surface water balance for shallow land burial systems used for waste disposal. Parameter estimates and estimation procedures are presented in detail in the form of a user's guide. Use of the model is illustrated with three examples based on analysis of data from Los Alamos, New Mexico and Rock Valley, Nevada. Use of the model in design of trench caps for shallow land burial systems is illustrated with the example applications at Los Alamos

The Characteristics of Turbidite Beds of Southwest Ryukyu Trench Floor: A new Approach From the X-ray Fluorescence Core Scanning Analysis

Science.gov (United States)

Hsiung, K. H.; Kanamatsu, T.; Ikehara, K.; Usami, K.; Saito, S.; Murayama, M.

2017-12-01

The southwest Ryukyu Trench near Taiwan is an ideal place for source-to-sink studies based on the distinctive sediment transport route between the terrestrial sediment source in Taiwan and the marine sink in the Ryukyu Trench. Using the bathymetric and seismic reflection data, we develop a sediment transport routes for understanding the ultimate sink of the southwest Ryukyu Trench floor. The southwest Ryukyu Trench floor can be regarded as the most distal depositional basin and isolated from the Ryukyu forearc basins. In addition, part of sediment from the proximal sources of the Ryukyu Islands and Yaeyama accretionary prism could be transported to the trench floor. We collected the piston core, PC04, from the southwest Ryukyu Trench floor of 6,147 m water depth in 3.23 m core length from cruise KR15-18, 2015. The coring site locates behind the natural levee of an obvious channel in the Ryukyu trench floor. The PC04 is composed of gray silty clay interbedded with numerous silt layers. Most of the silt layers are less than 2 cm in thickness. Based upon the core observation, X-ray fluorescence core scanning analysis and 14C age determinations, thirty-seven individual and thin beds were determined as turbidites. The results of X-ray fluorescence core scanning analysis provide continuous and high-resolution (1.0 mm of each point) assessment of relative change in the elemental ratios. Ca/Fe is a proxy for the terrigenous component of the sediment, indicating the High Ca and low Fe of each turbidite layers. Zr/Rb ratios of the marine sediments commonly used in the reflection of the original grain size variation. A large part of deep-sea turbidite beds are characterized by high Ca/Fe and Zr/Rb ratio values. These turbidite beds can be linked spatially over a distance of ˜200 km via submarine canyons within the Taiwan orogen. However, it is difficult to be linked temporally to certain events.

In-situ stabilization of radioactively contaminated low-level solid wastes buried in shallow trenches: an assessment

International Nuclear Information System (INIS)

Arora, H.S.; Tamura, T.; Boegly, W.J.

1980-09-01

The potential effectiveness of materials for in-situ encapsulation of low-level, radioactively contaminated solid waste buried in shallow trenches is enumerated. Cement, clay materials, and miscellaneous sorbents, aqueous and nonaqueous gelling fluids and their combinations are available to solidify contaminated free water in trenches, to fill open voids, and to minimize radionuclide mobility. The success of the grouting technique will depend on the availability of reliable geohydrologic data and laboratory development of a mix with enhanced sorption capacity for dominant radionuclides present in the trenches. A cement-bentonite-based grout mix with low consistency for pumping, several hours controlled rate of hardening, negligible bleeding, and more than 170 kPa (25 psi) compressive strength are a few of the suggested parameters in laboratory mix development. Cost estimates of a cement-bentonite-based grout mix indicate that effective and durable encapsulation can be accomplished at a reasonable cost (about $113 per cubic meter). However, extensive implementation of the method suggests the need for a field demonstration of the method. 53 references

Geological mapping of investigation Trench OL-TK13 at the Olkiluoto study site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Talikka, M.

2007-04-01

Geological mapping of investigation trench OL-TK13 was carried out by the Geological Survey of Finland at the Olkiluoto study site, Eurajoki, as a part Posiva Oy's site investigation programme for the development of an underground repository for nuclear waste. The east-west striking, ca. 250 m long trench is located in the vicinity of boreholes OL-KR23 and OL-KR27, ca. 250 m east of the ONKALO research facility. The mapping was performed from washed bedrock surface and rock types were determined macroscopically. The main rock types in OL-TK13 are diatexitic gneiss, veined gneiss, pegmatitic granite and K-feldspar porphyry. Mica gneiss and granite/granitized mica gneiss exist to a lesser extent. The diatexitic gneiss is the dominant rock type in the western part and the veined gneiss in the eastern part of the trench. The veined gneiss consists of pelitic mica gneiss paleosome and pegmatitic granite leucosome veins that are parallel to the foliation. In the diatexitic gneiss, the proportion of the leucosome veins and patches is over 50 % and the rock has an ambiguous texture. The pegmatitic granite also occurs as wider sections in the western part of the trench. The K-feldspar porphyry is characterized by potassium feldspar phenocrysts (diameter 4 deformation phase. The migmatitic gneisses were folded during the D 3 deformation phase resulting in small scale, tight and asymmetrical F 3 folds plunging moderately to the NE. During the fracture mapping, all fractures longer than one metre and all fractures intersecting the central thread were investigated. Measurements including orientation, length, fillings, Jr-value, Ja-value and undulation were recorded for a total of 860 fractures. The mean fracture density is 3.5 fracture/m. From the orientation data, three fracture sets were identified: (1) fractures parallel to the foliation, (2) subvertical N-S trending factures and (3) fractures dipping steeply to the N. ∼45 % of all fractures are 0.5-1.5 m in length and �

Flow and transport at the Las Cruces trench site: Experiment IIb

Energy Technology Data Exchange (ETDEWEB)

Vinson, J.; Hills, R.G. [New Mexico State Univ., Las Cruces, NM (United States); Wierenga, P.J.; Young, M.H. [Arizona Univ., Tucson, AZ (United States). Dept. of Soil and Water Science

1997-07-01

The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing.

Flow and transport at the Las Cruces trench site: Experiment IIb

International Nuclear Information System (INIS)

Vinson, J.; Hills, R.G.; Wierenga, P.J.; Young, M.H.

1997-07-01

The US Nuclear Regulatory Commission (NRC) has been directed by Congress in the Low Level Waste Policy Act of 1980 to develop regulatory guidance and assist the individual states and compacts in siting and assessing future low level radioactive waste (LLW) disposal facilities. Three water flow and solute transport experiments were performed as part of a comprehensive field trench study near Las Cruces, New Mexico to test deterministic and stochastic models of vadose zone flow and transport. This report presents partial results from the third experiment (experiment IIb). Experiments IIa and b were conducted on the North side of the trench, on a plot 1.22 m wide by 12 m long, perpendicular to the trench. The area was drip irrigated during two time periods with water containing a variety of tracers. The advance of the water front during the two irrigation episodes was measured with tensiometers and neutron probes. Solute front positions were determined from soil solution sampling through suction samplers and from disturbed sampling. The results from experiment IIb show predominantly downward water movement through the layered unsaturated soil, as evidenced from neutron probe data and gravimetric sampling. Tritium plumes were only half as deep and half as wide as the water plumes at 310 days after the beginning of experiment IIb. Chromium, applied as Cr(VI), moved a readily as, and similar to tritium, but there was a loss of mass due to reduction of Cr(VI) to Cr(III). Chloride and nitrate, initially present at high concentrations in the soil solution, were displaced by the low concentration irrigation water, resulting in chloride and nitrate concentration distributions that looked like negative images of the tritium distributions. The extensive data presented should serve well as a data base for model testing

Systematic approach to designing surface covers for uranium-mill tailings

International Nuclear Information System (INIS)

Beedlow, P.A.; Cadwell, L.L.; McShane, M.C.

1982-01-01

The wide range of environmental conditions present at uranium mill tailings sites precludes the use of a single type of surface cover. Surface covers must be designed on a site-specific basis. To facilitate site specific designs the UMTRA program is developing guidelines for designing surface covers. This paper presents a systematic approach to designing surface covers for tailings that can be applied under any site condition. The approach consists of three phases: (1) An assessment during which the degree of surface protection is determined. (2) A preliminary design that facilitates interaction with those designing other containment system elements. (3) A final design where the cost and effectiveness of the surface cover are determined. The types of information required to apply this approach are discussed

Coupling intensity and isostatic competition between subducting slab and overriding plate control trench motions and tectonics of the overriding plate

Science.gov (United States)

Wu, G.; Moresi, L. N.

2017-12-01

Trench motions not only reflect tectonic regimes on the overriding plate but also shed light on the competition between subducting slab and overriding plate, however, major controls over trench advance or retreat and their consequences are still illusive. We use 2D thermo-mechanical experiments to study the problem. We find that the coupling intensity particularly in the uppermost 200 km and the isostatic competition between subducting slab and overriding plate largely determine trench motion and tectonics of in the overriding plate. Coupling intensity is the result of many contributing factors, including frictional coefficient of brittle part of the subducting interface and the viscosity of the ductile part, thermal regime and rheology of the overriding plate, and water contents and magmatic activity in the subducting slab and overriding plate. In this study, we are not concerned with the dynamic evolution of individual controlling parameter but simply use effective media. For instance, we impose simple model parameters such as frictional coefficient and vary the temperature and strain-rate dependent viscosity of the weak layer between the subducting slab and overriding plate. In the coupled end-member case, strong coupling leads to strong corner flow, depth-dependent compression/extension, and mantle return flow on the overriding plate side. It results in fast trench retreat, broad overriding plate extension, and even slab breakoff. In the decoupled end-member case, weak coupling causes much weaker response on the overriding plate side compared with the coupled end-member case, and the subducting slab can be largely viewed as a conveyer belt. We find that the isostatic competition between the subducting slab and overriding plate also has a major control over trench motion, and may better be viewed in 3D models. This is consistent with the findings in previous 3D studies that trench motion is most pronounced close to the slab edge. Here we propose that the

Design criteria for XeF2 enabled deterministic transformation of bulk silicon (100) into flexible silicon layer

KAUST Repository

Hussain, Aftab M.

2016-07-15

Isotropic etching of bulk silicon (100) using Xenon Difluoride (XeF2) gas presents a unique opportunity to undercut and release ultra-thin flexible silicon layers with pre-fabricated state-of-the-art Complementary Metal Oxide Semiconductor (CMOS) electronics. In this work, we present design criteria and mechanism with a comprehensive mathematical model for this method. We consider various trench geometries and parametrize important metrics such as etch time, number of cycles and area efficiency in terms of the trench diameter and spacing so that optimization can be done for specific applications. From our theoretical analysis, we conclude that a honeycomb-inspired hexagonal distribution of trenches can produce the most efficient release of ultra-thin flexible silicon layers in terms of the number of etch cycles, while a rectangular distribution of circular trenches provides the most area efficient design. The theoretical results are verified by fabricating and releasing (varying sizes) flexible silicon layers. We observe uniform translation of design criteria into practice for etch distances and number of etch cycles, using reaction efficiency as a fitting parameter.

Design criteria for XeF2 enabled deterministic transformation of bulk silicon (100) into flexible silicon layer

KAUST Repository

Hussain, Aftab M.; Shaikh, Sohail F.; Hussain, Muhammad Mustafa

2016-01-01

Isotropic etching of bulk silicon (100) using Xenon Difluoride (XeF2) gas presents a unique opportunity to undercut and release ultra-thin flexible silicon layers with pre-fabricated state-of-the-art Complementary Metal Oxide Semiconductor (CMOS) electronics. In this work, we present design criteria and mechanism with a comprehensive mathematical model for this method. We consider various trench geometries and parametrize important metrics such as etch time, number of cycles and area efficiency in terms of the trench diameter and spacing so that optimization can be done for specific applications. From our theoretical analysis, we conclude that a honeycomb-inspired hexagonal distribution of trenches can produce the most efficient release of ultra-thin flexible silicon layers in terms of the number of etch cycles, while a rectangular distribution of circular trenches provides the most area efficient design. The theoretical results are verified by fabricating and releasing (varying sizes) flexible silicon layers. We observe uniform translation of design criteria into practice for etch distances and number of etch cycles, using reaction efficiency as a fitting parameter.

Hybrid surface design for robust superhydrophobicity.

Science.gov (United States)

Dash, Susmita; Alt, Marie T; Garimella, Suresh V

2012-06-26

Surfaces may be rendered superhydrophobic by engineering the surface morphology to control the extent of the liquid-air interface and by the use of low-surface-energy coatings. The droplet state on a superhydrophobic surface under static and dynamic conditions may be explained in terms of the relative magnitudes of the wetting and antiwetting pressures acting at the liquid-air interface on the substrate. In this paper, we discuss the design and fabrication of hollow hybrid superhydrophobic surfaces which incorporate both communicating and noncommunicating air gaps. The surface design is analytically shown to exhibit higher capillary (or nonwetting) pressure compared to solid pillars with only communicating air gaps. Six hybrid surfaces are fabricated with different surface parameters selected such that the Cassie state of a droplet is energetically favorable. The robustness of the surfaces is tested under dynamic impingement conditions, and droplet dynamics are explained using pressure-based transitions between Cassie and Wenzel states. During droplet impingement, the effective water hammer pressure acting due to the sudden change in the velocity of the droplet is determined experimentally and is found to be at least 2 orders of magnitude less than values reported in the literature. The experiments show that the water hammer pressure depends on the surface morphology and capillary pressure of the surface. We propose that the observed reduction in shock pressure may be attributed to the presence of air gaps in the substrate. This feature allows liquid deformation and hence avoids the sudden stoppage of the droplet motion as opposed to droplet behavior on smooth surfaces.

Designing Pulse Laser Surface Modification of H13 Steel Using Response Surface Method

Science.gov (United States)

Aqida, S. N.; Brabazon, D.; Naher, S.

2011-01-01

This paper presents a design of experiment (DOE) for laser surface modification process of AISI H13 tool steel in achieving the maximum hardness and minimum surface roughness at a range of modified layer depth. A Rofin DC-015 diffusion-cooled CO2 slab laser was used to process AISI H13 tool steel samples. Samples of 10 mm diameter were sectioned to 100 mm length in order to process a predefined circumferential area. The parameters selected for examination were laser peak power, overlap percentage and pulse repetition frequency (PRF). The response surface method with Box-Behnken design approach in Design Expert 7 software was used to design the H13 laser surface modification process. Metallographic study and image analysis were done to measure the modified layer depth. The modified surface roughness was measured using two-dimensional surface profilometer. The correlation of the three laser processing parameters and the modified surface properties was specified by plotting three-dimensional graph. The hardness properties were tested at 981 mN force. From metallographic study, the laser modified surface depth was between 37 μm and 150 μm. The average surface roughness recorded from the 2D profilometry was at a minimum value of 1.8 μm. The maximum hardness achieved was between 728 and 905 HV0.1. These findings are significant to modern development of hard coatings for wear resistant applications.

Evaluation of two stormwater infiltration trenches in central Copenhagen after 15 years of operation

DEFF Research Database (Denmark)

Bergman, Maria Kerstin; Hedegaard, Mathilde Jørgensen; Petersen, Mette Fjendbo

2011-01-01

to see whether the reduction in performance has continued and to determine how the system performs today. Water levels in the trenches were monitored for almost 4 months, and from this period seven events were selected to analyse the infiltration rate. A comparison with similar analyses on storm......Two stormwater infiltration trenches were installed in 1993 in an area in central Copenhagen. The system was monitored continuously for almost three years after establishment, and a small reduction in performance over that time, possibly due to clogging, was noted. A new study was conducted in 2009...... sequences from the first 3 years of operation shows that the infiltration has decreased since the establishment of the system 15 years ago. The decrease is statistically significant (p

Design and Implementation of Geothermal Energy Systems at West Chester University

Energy Technology Data Exchange (ETDEWEB)

Greg Cuprak

2011-08-31

West Chester University is launching a comprehensive transformation of its campus heating and cooling systems from traditional fossil fuels (coal, oil and natural gas) to geothermal. This change will significantly decrease the institution's carbon footprint and serve as a national model for green campus efforts. The institution is in the process of designing and implementing this project to build well fields, a pumping station and install connecting piping to provide the geothermal heat/cooling source for campus buildings. This project addresses the US Department of Energy Office of Energy Efficiency and Renewable Energy (EERE) goal to invest in clean energy technologies that strengthen the economy, protect the environment, and reduce dependence on foreign oil. In addition, this project advances EERE's efforts to establish geothermal energy as an economically competitive contributor to the US energy supply. For this grant, WCU will extend piping for its geo-exchange system. The work involves excavation of a trench approximately 8 feet wide and 10-12 feet deep located about 30 feet north of the curb along the north side of West Rosedale for a distance of approximately 1,300 feet. The trench will then turn north for the remaining distance (60 feet) to connect into the mechanical room in the basement of the Francis Harvey Green Library. This project will include crossing South Church Street near its intersection with West Rosedale, which will involve coordination with the Borough of West Chester. After installation of the piping, the trench will be backfilled and the surface restored to grass as it is now. Because the trench will run along a heavily-used portion of the campus, it will be accomplished in sections to minimize disruption to the campus as much as possible.

Evaluation of Anisotropic Biaxial Stress Induced Around Trench Gate of Si Power Transistor Using Water-Immersion Raman Spectroscopy

Science.gov (United States)

Suzuki, Takahiro; Yokogawa, Ryo; Oasa, Kohei; Nishiwaki, Tatsuya; Hamamoto, Takeshi; Ogura, Atsushi

2018-05-01

The trench gate structure is one of the promising techniques to reduce on-state resistance (R on) for silicon power devices, such as insulated gate bipolar transistors and power metal-oxide-semiconductor field-effect transistors. In addition, it has been reported that stress is induced around the trench gate area, modifying the carrier mobilities. We evaluated the one-dimensional distribution and anisotropic biaxial stress by quasi-line excitation and water-immersion Raman spectroscopy, respectively. The results clearly confirmed anisotropic biaxial stress in state-of-the-art silicon power devices. It is theoretically possible to estimate carrier mobility using piezoresistance coefficients and anisotropic biaxial stress. The electron mobility was increased while the hole mobility was decreased or remained almost unchanged in the silicon (Si) power device. The stress significantly modifies the R on of silicon power transistors. Therefore, their performance can be improved using the stress around the trench gate.

Flexural modeling of the elastic lithosphere at an ocean trench: A parameter sensitivity analysis using analytical solutions

Science.gov (United States)

Contreras-Reyes, Eduardo; Garay, Jeremías

2018-01-01

The outer rise is a topographic bulge seaward of the trench at a subduction zone that is caused by bending and flexure of the oceanic lithosphere as subduction commences. The classic model of the flexure of oceanic lithosphere w (x) is a hydrostatic restoring force acting upon an elastic plate at the trench axis. The governing parameters are elastic thickness Te, shear force V0, and bending moment M0. V0 and M0 are unknown variables that are typically replaced by other quantities such as the height of the fore-bulge, wb, and the half-width of the fore-bulge, (xb - xo). However, this method is difficult to implement with the presence of excessive topographic noise around the bulge of the outer rise. Here, we present an alternative method to the classic model, in which lithospheric flexure w (x) is a function of the flexure at the trench axis w0, the initial dip angle of subduction β0, and the elastic thickness Te. In this investigation, we apply a sensitivity analysis to both methods in order to determine the impact of the differing parameters on the solution, w (x). The parametric sensitivity analysis suggests that stable solutions for the alternative approach requires relatively low β0 values (rise bulge. The alternative method is a more suitable approach, assuming that accurate geometric information at the trench axis (i.e., w0 and β0) is available.

An electrostatic 3-phase linear stepper motor fabricated by vertical trench isolation technology

Science.gov (United States)

Sarajlic, Edin; Yamahata, Christophe; Cordero, Mauricio; Fujita, Hiroyuki

2009-07-01

We present the design, microfabrication and characterization of an electrostatic 3-phase linear stepper micromotor constructed with vertical trench isolation technology. This suitable technology was used to create a monolithic stepper motor with high-aspect-ratio poles and an integrated 3-phase electrical network in the bulk of a standard single-crystal silicon wafer. The shuttle of the stepper motor is suspended by a flexure to avoid any mechanical contact during operation, enhancing the precision, repeatability and reliability of the stepping motion. The prototype is capable of a maximum travel of +/-26 µm (52 µm) at an actuation voltage of 30 V and a step size of 1.4 µm during a half-stepping sequence. This work was presented in part at the 19th MicroMechanics Europe Workshop (MME), 28-30 September 2008, Aachen, Germany.

How broad and deep is the region of chemical alteration of oceanic plates at trenches?

Science.gov (United States)

Ranero, C. R.; Grevemeyer, I.; Barckhausen, U.

2017-12-01

Different lines of evidence indicate that oceanic plates are affected by pervasive bending-related deformation approaching ocean trenches. Results from active-seismic work support that deformation provides paths for exchange between hydrosphere and lithosphere, possibly causing chemical alteration of the incoming lithosphere. Much work focused on the potential transformation of peridotite to serpentine in the uppermost mantle of incoming plates, but there is no consensus on the region where it may occur or the intensity of alteration, let alone on limiting factors for the process. Teleseismic (large-great) earthquakes with normal-fault mechanism in the outer rise region have been often called to speculate on the depth of penetration of plate hydration. However, large-great outer-rise earthquakes may be related to stress changes due to slab pull after decoupling along the inter-plate boundary, and not necessarily controlled by bending stresses only. If so, the majority of the time the depth of water percolation may be related to local bending stresses expressed by micro-earthquakes rather than large events. Seismic images and multibeam bathymetry from lithosphere of similar thermal thickness from different trenches display a remarkable variability of the intensity of bending-related deformation along the subduction zones where plate age does not change significantly indicating that the intensity of deformation (not the depth) and perhaps hydration is very variable in space and not controlled by plate age. Seismic images showing hundreds of kilometers perpendicular to the trench into the incoming plate show that the bending-related deformation reaches mantle under the outer rise, well before the lithosphere plunges into the trench and develops the marked bend-faulting fabric observable in bathymetric maps. Thus, alteration occurs in a hundreds-of-km wide area, with deformation intensity related to local characteristics, and deformation depth to plate age.

Design criteria for XeF{sub 2} enabled deterministic transformation of bulk silicon (100) into flexible silicon layer

Energy Technology Data Exchange (ETDEWEB)

Hussain, Aftab M.; Shaikh, Sohail F.; Hussain, Muhammad M., E-mail: muhammadmustafa.hussain@kaust.edu.sa [Integrated Nanotechnology Laboratory (INL) and Integrated Disruptive Electronics Applications (IDEA) Laboratory, Computer Electrical Mathematical Science and Engineering Division, King Abdullah University of Science and Technology - KAUST, Thuwal 23955-6900 (Saudi Arabia)

2016-07-15

Isotropic etching of bulk silicon (100) using Xenon Difluoride (XeF{sub 2}) gas presents a unique opportunity to undercut and release ultra-thin flexible silicon layers with pre-fabricated state-of-the-art Complementary Metal Oxide Semiconductor (CMOS) electronics. In this work, we present design criteria and mechanism with a comprehensive mathematical model for this method. We consider various trench geometries and parametrize important metrics such as etch time, number of cycles and area efficiency in terms of the trench diameter and spacing so that optimization can be done for specific applications. From our theoretical analysis, we conclude that a honeycomb-inspired hexagonal distribution of trenches can produce the most efficient release of ultra-thin flexible silicon layers in terms of the number of etch cycles, while a rectangular distribution of circular trenches provides the most area efficient design. The theoretical results are verified by fabricating and releasing (varying sizes) flexible silicon layers. We observe uniform translation of design criteria into practice for etch distances and number of etch cycles, using reaction efficiency as a fitting parameter.

Tectonics and Non-isostatic Topography of the Mariana Trench and Adjacent Plates

Science.gov (United States)

Hongyu, L.; Lin, J.; Zhou, Z.; Zhang, F.

2017-12-01

Multi-types of geophysical data including multibeam bathymetry, sediment thickness, gravity anomaly, and crustal magnetic age were analyzed to investigate tectonic processes of the Mariana Trench and the surrounding plates. We calculated non-Airy-isostatic topography by removing from the observed bathymetry the effects of sediment loading, thermal subsidence, and Airy local isostatically-compensated topography. The Mariana Trench was found to be associated with a clearly defined zone of negative non-isostatic topography, which was caused by flexural bending of the subducting Pacific plate and with the maximum depth anomaly and flexural bending near the Challenger Deep. In contrast, the Caroline Ridge and Caroline Islands Chain have much more subdued non-isostatic topography, indicating their higher topography is largely compensated by thicker crust. Along the Mariana Trough, the northern and central segments appear to be associated with relatively low magma supply as indicated by the relatively low topography and thin crust. In contrast, the southern Mariana Trough is associated with relatively high magma supply as indicated by the relatively high and smoother topography, an axial high spreading center, and relatively thick crust. The southern end of the Mariana Trough was also found to be associated with positive non-isostatic topographic anomaly, which might be caused by the complex tectonic deformation of the overriding Mariana and Philippine Sea plates and their interaction with the subducting Pacific plate. Analysis further revealed that the southern Mariana Arc, located between the Mariana Trench and Mariana Trough, is associated with positive non-isostatic topographic anomalies, which may be explained by the late stage magmatic loading on the older and thus stronger lithospheric plate of the Mariana volcanic arc.

Highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles

Science.gov (United States)

Huang, Yuewang; Zhao, Qiancheng; Sharac, Nicholas; Ragan, Regina; Boyraz, Ozdal

2015-05-01

We demonstrate the fabrication of a highly nonlinear sub-micron silicon nitride trench waveguide coated with gold nanoparticles for plasmonic enhancement. The average enhancement effect is evaluated by measuring the spectral broadening effect caused by self-phase-modulation. The nonlinear refractive index n2 was measured to be 7.0917×10-19 m2/W for a waveguide whose Wopen is 5 μm. Several waveguides at different locations on one wafer were measured in order to take the randomness of the nanoparticle distribution into consideration. The largest enhancement is measured to be as high as 10 times. Fabrication of this waveguide started with a MEMS grade photomask. By using conventional optical lithography, the wide linewidth was transferred to a wafer. Then the wafer was etched anisotropically by potassium hydroxide (KOH) to engrave trapezoidal trenches with an angle of 54.7º. Side wall roughness was mitigated by KOH etching and thermal oxidation that was used to generate a buffer layer for silicon nitride waveguide. The guiding material silicon nitride was then deposited by low pressure chemical vapor deposition. The waveguide was then patterned with a chemical template, with 20 nm gold particles being chemically attached to the functionalized poly(methyl methacrylate) domains. Since the particles attached only to the PMMA domains, they were confined to localized regions, therefore forcing the nanoparticles into clusters of various numbers and geometries. Experiments reveal that the waveguide has negligible nonlinear absorption loss, and its nonlinear refractive index can be greatly enhanced by gold nano clusters. The silicon nitride trench waveguide has large nonlinear refractive index, rendering itself promising for nonlinear applications.

Biological intrusion of low-level-waste trench covers

International Nuclear Information System (INIS)

Hakonson, T.E.; Gladney, E.S.

1981-01-01

The long-term integrity of low-level waste shallow land burial sites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. Past research on low-level waste shallow land burial methods has emphasized physical (i.e., water infiltration, soil erosion) and chemical (radionuclide leaching) processes that can cause waste site failure and subsequent radionuclide transport. The purpose of this paper is to demonstrate the need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatments. Plants and animals not only can transport radionuclides to the ground surface via root systems and soil excavated from the cover profile by animal burrowing activities, but they modify physical and chemical processes within the cover profile by changing the water infiltration rates, soil erosion rates and chemical composition of the soil. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and soil overburden depth. The rate of biological intrusion through the various barrier materials is being evaluated through the use of activatable stable tracers

Optimal design for MRI surface coils

International Nuclear Information System (INIS)

Rivera, M.; Vaquero, J.J.; Santos, A.; Pozo, F. del; Ruiz-Cabello, J.

1997-01-01

To demonstrate the possibility of designing and constructing specific surface coils or antennae for MRI viewing of each particular tissue producing better results than those provided by a general purpose surface coil. The study was performed by the Bioengineering and Telemedicine Group of Madrid Polytechnical University and was carried out at the Pluridisciplinary Institute of the Universidad Complutense in Madrid, using a BMT-47/40 BIOSPEC resonance unit from Bruker. Surface coils were custom-designed and constructed for each region to be studied, and optimized to make the specimen excitation field as homogeneous as possible, in addition to reducing the brightness artifact. First, images were obtained of a round, water phantom measuring 50 mm in diameter, after which images of laboratory rats and rabbits were obtained. The images thus acquired were compared with the results obtained with the coil provided by the manufacturer of the equipment, and were found to be of better quality, allowing the viewing of deeper tissue for the specimen as well as reducing the brightness artifact. The construction of surface coils for viewing specific tissues or anatomical regions improves image quality. The next step in this ongoing project will be the application of these concepts to units designed for use in humans. (Author) 14 refs

Tsunami Numerical Simulation for Hypothetical Giant or Great Earthquakes along the Izu-Bonin Trench

Science.gov (United States)

Harada, T.; Ishibashi, K.; Satake, K.

2013-12-01

We performed tsunami numerical simulations from various giant/great fault models along the Izu-Bonin trench in order to see the behavior of tsunamis originated in this region and to examine the recurrence pattern of great interplate earthquakes along the Nankai trough off southwest Japan. As a result, large tsunami heights are expected in the Ryukyu Islands and on the Pacific coasts of Kyushu, Shikoku and western Honshu. The computed large tsunami heights support the hypothesis that the 1605 Keicho Nankai earthquake was not a tsunami earthquake along the Nankai trough but a giant or great earthquake along the Izu-Bonin trench (Ishibashi and Harada, 2013, SSJ Fall Meeting abstract). The Izu-Bonin subduction zone has been regarded as so-called 'Mariana-type subduction zone' where M>7 interplate earthquakes do not occur inherently. However, since several M>7 outer-rise earthquakes have occurred in this region and the largest slip of the 2011 Tohoku earthquake (M9.0) took place on the shallow plate interface where the strain accumulation had considered to be a little, a possibility of M>8.5 earthquakes in this region may not be negligible. The latest M 7.4 outer-rise earthquake off the Bonin Islands on Dec. 22, 2010 produced small tsunamis on the Pacific coast of Japan except for the Tohoku and Hokkaido districts and a zone of abnormal seismic intensity in the Kanto and Tohoku districts. Ishibashi and Harada (2013) proposed a working hypothesis that the 1605 Keicho earthquake which is considered a great tsunami earthquake along the Nankai trough was a giant/great earthquake along the Izu-Bonin trench based on the similarity of the distributions of ground shaking and tsunami of this event and the 2010 Bonin earthquake. In this study, in order to examine the behavior of tsunamis from giant/great earthquakes along the Izu-Bonin trench and check the Ishibashi and Harada's hypothesis, we performed tsunami numerical simulations from fault models along the Izu-Bonin trench

Soil, plant, and structural considerations for surface barriers in arid environments: Application of results from studies in the Mojave Desert near Beatty, Nevada

Science.gov (United States)

Andraski, Brian J.; Prudic, David E.; ,

1997-01-01

The suitability of a waste-burial site depends on hydrologic processes that can affect the near-surface water balance. In addition, the loss of burial trench integrity by erosion and subsidence of trench covers may increase the likelihood of infiltration and percolation, thereby reducing the effectiveness of the site in isolating waste. Although the main components of the water balance may be defined, direct measurements can be difficult, and actual data for specific locations are seldom available. A prevalent assumption is that little or no precipitation will percolate to buried wastes at an arid site. Thick unsaturated zones, which are common to arid regions, are thought to slow water movement and minimize the risk of waste migration to the underlying water table. Thus, reliance is commonly placed on the natural system to isolate contaminants at waste-burial sites in the arid West.Few data are available to test assumptions about the natural soil-water flow systems at arid sites, and even less is known about how the natural processes are altered by construction of a waste-burial facility. The lack of data is the result of technical complexity of hydraulic characterization of the dry, stony soils, and insufficient field studies that account for the extreme temporal and spatial variations in precipitation, soils, and plants in arid regions. In 1976, the U.S. Geological Survey (USGS) began a long-term study at a waste site in the Mojave Desert. This paper summarizes the findings of ongoing investigations done under natural-site and waste-burial conditions, and discusses how this information may be applied to the design of surface barriers for waste sites in arid environments.The waste-burial site is in one of the most arid parts of the United States and is about 40 km northeast of Death Valley, near Beatty, Nev. (Figure 1). Precipitation averaged 108 mm/yr during 1981-1992. The water table is 85-115 m below land surface (Fischer, 1992). Sediments are largely alluvial

Hydrogeologic Characterization Data from the Area 5 Shallow Soil Trenches

International Nuclear Information System (INIS)

Bechtel Nevada Geotechnical Sciences

2005-01-01

Four shallow soil trenches excavated in the vicinity of the Area 5 Radioactive Waste Management Site at the Nevada Test Site were sampled in 1994 to characterize important physical and hydrologic parameters which can affect the movement of water in the upper few meters of undisturbed alluvium. This report describes the field collection of geologic samples and the results of laboratory analyses made on these samples. This report provides only qualitative analyses and preliminary interpretations

Solid Waste Operations Complex W-113, Detail Design Report (Title II). Volume 5: Design validation assessments and lists

International Nuclear Information System (INIS)

1995-09-01

The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. The following Code Evaluation analyzes the applicable sections of the National Fire Protection Association (NFPA) 101, Life Safety Code, 1994 Edition and the 1994 Edition of the Uniform Building Code (UBC) to the W113 Trench Enclosure. A Building Code Analysis generally establishes four primary design criteria: occupancy classification; separation requirements; egress requirements; and construction type. The UBC establishes requirements for all criteria. This analysis is limited to the Trench Enclosure Building. The General Office Building and the Retrieval Staff Change Building is not within the scope of this analysis

Decision support system for surface irrigation design

OpenAIRE

Gonçalves, José M.; Pereira, L.S.

2009-01-01

The SADREG decision support system was developed to help decision makers in the process of design and selection of farm surface irrigation systems to respond to requirements of modernization of surface irrigation—furrow, basin, and border irrigation. It includes a database, simulation models, user-friendly interfaces, and multicriteria analysis models. SADREG is comprised of two components: design and selection. The first component applies database information, and through several si...

Evaluation of Proposed New LLW Disposal Activity Disposal of Compacted Job Control Waste, Non-compactible, Non-incinerable Waste, And Other Wasteforms In Slit Trenches

International Nuclear Information System (INIS)

WILHITE, ELMER L.

2000-01-01

The effect of trench disposal of low-level wasteforms that were not analyzed in the original performance assessment for the E-Area low-level waste facility, but were analyzed in the revised performance assessment is evaluated. This evaluation was conducted to provide a bridge from the current waste acceptance criteria, which are based on the original performance assessment, to those that will be developed from the revised performance assessment. The conclusion of the evaluation is that any waste except for materials that would retain radionuclides more strongly than soil that meets the radionuclide concentration of package limits for trench burial based on the revised performance assessment, and presented in Table 1 of this document, is suitable for trench disposal; provided that, for cellulosic material the current 40 percent restriction is retained. Table 2 of this document lists materials acceptable for trench disposal

DESIGNING OF DEVELOPED SURFACES OF COMPLEX PARTS

Directory of Open Access Journals (Sweden)

S. S. Tyshchenko

2017-04-01

Full Text Available Purpose. The paper focuses on ensuring the rational choice of parameters of the mating surfaces of parts when designing process equipment based on the methods of artificial intelligence. Methodology. The paper considers the geometric model of a ruled developed surface, the conditions of existence of such a surface and provides a generalized algorithm for surface plotting regardless of the type of the working element or the machine-building product. One of the most common technical surfaces are the ruled ones, among which a special position is occupied by developed surfaces (thanks to their differential-parametric properties: surface tangent plane is n contact along the rectilinear generator and does not change its position in space when changing the point of contact; surfaces can be produced by bending sheet metal. These provisions enable a product manufacturer to save significant material and energy means, therefore, the development of geometric models of such surfaces is an important task. Findings. We analyzed the geometrical model of the developed surface which is incident to two guides. Experimental studies have shown the applicationprospectivity of semi-digger moldboards on moldboard plows, particularly on the double-deck ones. Taking into account the operating speed of the plow 2.8 m/s, the plant residues plowing percentage for plow with semi-digger moldboards is 98.9%, and with the digger ones – 96.1%. Originality. According to results: 1 the approaches to solving the problem of recognition of wear conditions of the tested interface, depicted by its conceptual model, were elaborated; 2 the corresponding algorithms of the computational procedures were built; 3 the mathematical model that determines the effect of the parameters of the contacting surfaces on their performance properties – linear wear rate during the normal wear and tear was developed; 4 for this model the theoretical prerequisite of use for the random mating study were

Analysis of OFF-state and ON-state performance in a silicon-on-insulator power MOSFET with a low-k dielectric trench

International Nuclear Information System (INIS)

Wang Zhigang; Zhang Bo; Li Zhaoji

2013-01-01

A novel silicon-on-insulator (SOI) MOSFET with a variable low-k dielectric trench (LDT MOSFET) is proposed and its performance and characteristics are investigated. The trench in the drift region between drain and source is filled with low-k dielectric to extend the effective drift region. At OFF state, the low-k dielectric trench (LDT) can sustain high voltage and enhance the dielectric field due to the accumulation of ionized charges. At the same time, the vertical dielectric field in the buried oxide can also be enhanced by these ionized charges. Additionally, ON-state analysis of LDT MOSFET demonstrates excellent forward characteristics, such as low gate-to-drain charge density ( 2 ) and a robust safe operating area (0–84 V). (semiconductor devices)

Studies on Slurry Design Fundamentals for Advanced CMP Applications

KAUST Repository

Basim, G. B.; Karagoz, A.; Ozdemir, Z.; Vakarelski, Ivan Uriev; Chen, Long

2013-01-01

New developments and device performance requirements in microelectronics industry add to the challenges in chemical mechanical planarization (CMP) process. One of the recently introduced materials is germanium which enables improved performance through better channel mobility in shallow trench isolation (STI) applications. This paper reports on the slurry design alternatives for Ge CMP with surfactant mediation to improve on the silica/germanium selectivity using colloidal silica slurry. In addition to the standard CMP tests to evaluate the material removal rates, atomic force microscopy (AFM) based wear tests were also conducted to evaluate single particle-surface interaction of the polishing system. Furthermore, nature of the surface oxide film of germanium was studied through contact angle measurements and surface roughness tested by AFM. It was observed that the CMP selectivity of the silica/germanium system and defectivity control were possible with a reasonable material removal rate value by using self-assembled structures of cationic surfactants.

Studies on Slurry Design Fundamentals for Advanced CMP Applications

KAUST Repository

Basim, G. B.

2013-06-14

New developments and device performance requirements in microelectronics industry add to the challenges in chemical mechanical planarization (CMP) process. One of the recently introduced materials is germanium which enables improved performance through better channel mobility in shallow trench isolation (STI) applications. This paper reports on the slurry design alternatives for Ge CMP with surfactant mediation to improve on the silica/germanium selectivity using colloidal silica slurry. In addition to the standard CMP tests to evaluate the material removal rates, atomic force microscopy (AFM) based wear tests were also conducted to evaluate single particle-surface interaction of the polishing system. Furthermore, nature of the surface oxide film of germanium was studied through contact angle measurements and surface roughness tested by AFM. It was observed that the CMP selectivity of the silica/germanium system and defectivity control were possible with a reasonable material removal rate value by using self-assembled structures of cationic surfactants.

Interactive Design of Developable Surfaces

KAUST Repository

Tang, Chengcheng

2016-01-15

We present a new approach to geometric modeling with developable surfaces and the design of curved-creased origami. We represent developables as splines and express the nonlinear conditions relating to developability and curved folds as quadratic equations. This allows us to utilize a constraint solver, which may be described as energy-guided projection onto the constraint manifold, and which is fast enough for interactive modeling. Further, a combined primal-dual surface representation enables us to robustly and quickly solve approximation problems.

Interactive Design of Developable Surfaces

KAUST Repository

Tang, Chengcheng; Bo, Pengbo; Wallner, Johannes; Pottmann, Helmut

2016-01-01

We present a new approach to geometric modeling with developable surfaces and the design of curved-creased origami. We represent developables as splines and express the nonlinear conditions relating to developability and curved folds as quadratic equations. This allows us to utilize a constraint solver, which may be described as energy-guided projection onto the constraint manifold, and which is fast enough for interactive modeling. Further, a combined primal-dual surface representation enables us to robustly and quickly solve approximation problems.

Oceanographic cruise: Coral Sea, Arafura Sea, and Java Trench, April - May 1969 (NODC Accession 7100914)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This report contains oceanographic data which was obtained aboard HMAS DIAMANTINA during an oceanographic cruise in the Coral Sea, Arafura Sea, and Java Trench...

Surface design methodology - challenge the steel

Science.gov (United States)

Bergman, M.; Rosen, B.-G.; Eriksson, L.; Anderberg, C.

2014-03-01

The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or "feeling" for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA.

Low-Level Burial Grounds dangerous waste permit application: Request for exemption from lined trench requirements and from land disposal restrictions for residual liquid at 218-E-12B Burial Ground Trench 94

International Nuclear Information System (INIS)

1992-10-01

This document has been prepared and is being submitted to the respective agencies to satisfy three objectives of the US Department of Energy (DOE) Richland Field Office (DOE-RL) concerning Trench 94 of the 218-E-12B Burial Ground. The 218-E-12B Burial Ground is located in the 200 East Area of the Hanford Facility. Figure 1-1 shows the general location of the Hanford Site. The 218-E-12B Burial Ground is one of eight burial grounds included in the Low-Level Burial Grounds (LLBG), a treatment, storage and/or disposal (TSD) unit. Decommissioned, defueled naval submarine reactor compartments (SRCs) contain radioactivity caused by exposure of structural components to neutrons during normal operation of the submarines. After all the alternatives were evaluated in the US Department of the Navy 1984 environmental impact statement (EIS) (USN 1984), land burial of the SRCs was selected as the preferred disposal option. The SRCs currently are sent to Trench 94 of the 218-E-12B Burial Ground. In addition to radioactivity, the SRCs disposed in. The DOE-RL's three objectives in preparing and submitting this document are as follows. Request from Ecology an exemption from dangerous waste landfill liner and leachate collection and removal system (hereinafter referred to as liner/leachate system) requirements for Trench 94 of the 218-E-12B Burial Ground. Petition Ecology to exempt residual liquid in the SRCs from land disposal restrictions. Obtain EPA Region 10 review and comment on the request to Ecology for exemption from liner/leachate system requirements

Antibacterial surface design - Contact kill

Science.gov (United States)

Kaur, Rajbir; Liu, Song

2016-08-01

Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

Ultrahigh-density trench cpacitors in silicon and their application to integrated DC-DC conversion

NARCIS (Netherlands)

Roozeboom, F.; Bergveld, H.J.; Nowak, K.; Le Cornec, F.; Guiraud, L.; Bunel, C.; Iochem, S.; Ferreira, J.; Ledain, S.; Pieraerts, E.; Pommier, M.

2009-01-01

This paper addresses silicon-based integration of passive components applied to 3D integration with dies of other technologies within one package. Particularly, the development of high-density trench capacitors has enabled the realization of small-formfactor DC-DC converters. As illustration, an

Light extinction and scattering from individual and arrayed high-aspect-ratio trenches in metal

DEFF Research Database (Denmark)

Roberts, Alexander; Søndergaard, Thomas; Chirumamilla, Manohar

2016-01-01

for a two-dimensional scatterer. We construct a simple resonator model which predicts the wavelength-dependent extinction, scattering, and absorption cross section of the trench and compare the model findings with full numerical simulations. Both extinction and scattering cross sections are mainly...

Calcareous nannofossil biostratigraphy and geochronology of Neogene trench-slope cover sediments in the south Boso Peninsula, central Japan: Implications for the development of a shallow accretionary complex

Science.gov (United States)

Chiyonobu, Shun; Yamamoto, Yuzuru; Saito, Saneatsu

2017-07-01

The geological structure and calcareous nannofossil biostratigraphy of the Middle to Late Miocene trench-slope succession in the southern Boso Peninsula, central Japan, were examined to obtain chronological constraints on the accretion and formation of the trench-slope architecture. As a result, trench-slope cover sediments (Kinone and Amatsu Formations) are clearly distinguishable from the Early Miocene Hota accretionary complex (Hota Group). The Hota accretionary complex was deposited below the carbonate compensation depth (CCD) and was affected by intense shearing, forming an east-west trending and south-verging fold and thrust belt. In contrast, the trench-slope cover sediments basically have a homoclinal dip, except at the northern rim where they are bounded by fault contact. They contain many species of calcareous nannofossils and foraminifers, which are indicative of their depositional environment above the CCD, and they show shallowing-upward sedimentary structures. Biostratigraphy revealed that the depositional age of the trench-slope sediments is ca. 15-5.5 Ma, suggesting that there is an approximately 2 myr hiatus beween the Miura Group and the underlying accretionary prism. Based on these results, the age of accretion of the Hota Group is inferred to be between ca. 17-15 Ma, and the group is covered by trench-slope sediments overlain on it after ca. 15 Ma. The timing of accretion and the age of the trench-slope basin tend to be younger southward of the Boso Peninsula. The accretionary system of the Boso Peninsula apparently developed in two stages, in the Middle Miocene and in the Late Miocene to Pliocene.

Ways of increasing safety in mining at the Berezovskii-1 surface mine

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, N N; Malyarenko, V I

1986-12-01

Methods are descrubed wgucg were developed to alleviate or prevent the effects of landslides in a Kansk-Achinsk surface mine. Such a landslide took place in 1983 at the Berezovskii-1 mine when 250 m of an excavation trench suffered a collapse involving 680,000 mT of materials. Surveys revealed large zones of flooded ground with high proportions of argillites and aleurolites which swell in the presence of water. To keep costs down, a method using gravity is proposed for safety of re-excavation work near spoil banks. In this method a pillar of rock is left at the base of the spoil bank, the edge of the slope of which is moved back from the trench. Hard rock is placed at the leading edge of the spoil bank. The stability factor of the trench side may be raised from 0.87 to 1.12, and this is accompanied by savings in labor and costs.

Seismic Structure of the Oceanic Plate Entering the Central Part of the Japan Trench Obtained from Ocean-Bottom Seismic Data

Science.gov (United States)

Ohira, A.; Kodaira, S.; Fujie, G.; No, T.; Nakamura, Y.; Miura, S.

2017-12-01

In trench-outer rise regions, the normal faults develop due to the bending of the incoming plate, which cause numerous normal-faulting earthquakes and systematic structural variations toward trenches. In addition to the effects on the bend-related normal fault, structural variations which are interpreted to be attributed to pseudofaults, a fracture zone, and petit-spot volcanic activities are observed in the oceanic plate entering the central part of the Japan Trench, off Miyagi. In May-June 2017, to understand detail structural variations and systematic structural changes of the oceanic plate toward the trench, we conducted an active-source seismic survey off Miyagi using R/V Kaimei, a new research vessel of JAMSTEC. Along a 100 km-long seismic profile which is approximately perpendicular to the trench axis, we deployed 40 ocean-bottom seismometers at intervals of 2 km and fired a large airgun array (total volume 10,600 cubic inches) with 100 m shooting intervals. Multi-channel seismic reflection data were also collected along the profile. On OBS records we observed refractions from the sedimentary layer and the oceanic crust (Pg), wide-angle reflections from the crust-mantle boundary (PmP), and refractions from the uppermost mantle (Pn). Pg is typically observed clearly at near offsets (approximately 20 km) but it highly attenuates at far offsets (> 20 km). A triplication of Pg-PmP-Pn with strong amplitudes is observed at ranges from 30 km to 60 km offsets. Pn is typically weak and its apparent velocity is approximately 8 km/sec. High attenuation of Pg and weak Pn may indicate the complex crustal structure related to petit-spot volcanic activities and/or a fracture zone, which are recognized in bathymetry data around the profile.

Growth rate and surface morphology of 4H-SiC crystals grown from Si-Cr-C and Si-Cr-Al-C solutions under various temperature gradient conditions

Science.gov (United States)

Mitani, Takeshi; Komatsu, Naoyoshi; Takahashi, Tetsuo; Kato, Tomohisa; Fujii, Kuniharu; Ujihara, Toru; Matsumoto, Yuji; Kurashige, Kazuhisa; Okumura, Hajime

2014-09-01

The growth rate and surface morphology of 4H-SiC crystals prepared by solution growth with Si1-xCrx and Si1-x-yCrxAly (x=0.4, 0.5 and 0.6; y=0.04) solvents were investigated under various temperature conditions. The growth rate was examined as functions of the temperature difference between the growth surface and C source, the amount of supersaturated C and supersaturation at the growth surface. We found that generation of trench-like surface defects in 4H-SiC crystals was suppressed using Si1-x-yCrxAly solvents even under highly supersaturated conditions where the growth rate exceeded 760 μm/h. Conversely, trench-like defects were observed in crystals grown with Si1-xCrx solvents under all experimental conditions. Statistical observation of the macrostep structure showed that the macrostep height in crystals grown with Si1-x-yCrxAly solvents was maintained at lower levels than that obtained using Si1-xCrx solvents. Addition of Al prevents the macrosteps from developing into large steps, which are responsible for the generation of trench-like surface defects.

Design surface covers: an approach to long-term waste site stabilization

International Nuclear Information System (INIS)

Beedlow, P.A.; Cadwell, L.L.; McShane, M.C.

1983-02-01

The wide range of existing environmental conditions, potential contaminants and available cover materials at waste disposal sites necessitates site-specific designing of surface covers for effective long-term erosion resistance. This paper presents a systematic approach to designing surface covers for hazardous waste repositories that can be tailored to conditions at any site. The approach consists of three phases: (1) an assessment, during which the degree of required surface protection (erosion potential) is determined; (2) a preliminary design that integrates surface cover design with the need to minimize transport of contaminants; and (3) a final design, where the cost and effectiveness of the surface cover are determined. 1 figure

Prototype Hanford Surface Barrier: Design basis document

International Nuclear Information System (INIS)

Myers, D.R.; Duranceau, D.A.

1994-11-01

The Hanford Site Surface Barrier Development Program (BDP) was organized in 1985 to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site and other arid sites. This document provides the basis of the prototype barrier. Engineers and scientists have momentarily frozen evolving barrier designs and incorporated the latest findings from BDP tasks. The design and construction of the prototype barrier has required that all of the various components of the barrier be brought together into an integrated system. This integration is particularly important because some of the components of the protective barreir have been developed independently of other barreir components. This document serves as the baseline by which future modifications or other barrier designs can be compared. Also, this document contains the minutes of meeting convened during the definitive design process in which critical decisions affecting the prototype barrier's design were made and the construction drawings

Surface laser marking optimization using an experimental design approach

Science.gov (United States)

Brihmat-Hamadi, F.; Amara, E. H.; Lavisse, L.; Jouvard, J. M.; Cicala, E.; Kellou, H.

2017-04-01

Laser surface marking is performed on a titanium substrate using a pulsed frequency doubled Nd:YAG laser ( λ= 532 nm, τ pulse=5 ns) to process the substrate surface under normal atmospheric conditions. The aim of the work is to investigate, following experimental and statistical approaches, the correlation between the process parameters and the response variables (output), using a Design of Experiment method (DOE): Taguchi methodology and a response surface methodology (RSM). A design is first created using MINTAB program, and then the laser marking process is performed according to the planned design. The response variables; surface roughness and surface reflectance were measured for each sample, and incorporated into the design matrix. The results are then analyzed and the RSM model is developed and verified for predicting the process output for the given set of process parameters values. The analysis shows that the laser beam scanning speed is the most influential operating factor followed by the laser pumping intensity during marking, while the other factors show complex influences on the objective functions.

Development of ecologically safe method for main oil and gas pipeline trenching

Directory of Open Access Journals (Sweden)

Akhmedov Asvar Mikdadovich

2014-05-01

Full Text Available Constructive, technical and technological reliability of major pipeline ensures ecological safety on different stages of life circle - beginning with project preparation activities up to the end of major pipeline operation. Even in the process of transition into new life circle stage, no matter if the pipeline needs major repairs or reconstruction, such technical and technological solutions should be found, which would preserve ecological stability of nature-anthropogenic system. Development of ecology protection technologies of construction, reconstruction and major repairs of main pipelines is of great importance not only for a region, but ensures ecological safety across the globe. The article presents a new way of trenching the main oil and gas pipeline, preservation and increase of ecological safety during its service. The updated technological plan is given in the paper for overhaul of the main oil and gas pipeline using the new technology of pipeline trenching. The suggested technical solution contributes to environment preservation with the help of deteriorating shells - the shells’ material decomposes into environment-friendly components: carbon dioxide, water and humus. The quantity of polluting agents in the atmosphere decreases with the decrease of construction term and quantity of technical equipment.

Bench-scale treatability testing of biological, UV oxidation, distillation, and ion-exchange treatment of trench water from a low-level radioactive waste disposal area at West Valley, New York

Energy Technology Data Exchange (ETDEWEB)

Sundquist, J.A.; Gillings, J.C. [Ecology and Environment, Inc. (United States); Sonntag, T.L. [New York State Energy Research and Development Authority (United States); Denault, R.P. [Pacific Nuclear, Inc. (United States)

1993-03-01

Ecology and Environment, Inc. (E and E), under subcontract to Pacific Nuclear Services (PNS), conducted for the New York State Energy Research and Development Authority (NYSERDA) treatability tests to support the selection and design of a treatment system for leachate from Trench 14 of the West Valley State-Licensed, Low-Level Radioactive Waste Disposal Area (SDA). In this paper E and E presents and discusses the treatability test results and provides recommendations for the design of the full-scale treatment system.

Tile-based rigidization surface parametric design study

Science.gov (United States)

Giner Munoz, Laura; Luntz, Jonathan; Brei, Diann; Kim, Wonhee

2018-03-01

Inflatable technologies have proven useful in consumer goods as well as in more recent applications including civil structures, aerospace, medical, and robotics. However, inflatable technologies are typically lacking in their ability to provide rigid structural support. Particle jamming improves upon this by providing structures which are normally flexible and moldable but become rigid when air is removed. Because these are based on an airtight bladder filled with loose particles, they always occupy the full volume of its rigid state, even when not rigidized. More recent developments in layer jamming have created thin, compact rigidizing surfaces replacing the loose volume of particles with thinly layered surface materials. Work in this area has been applied to several specific applications with positive results but have not generally provided the broader understanding of the rigidization performance as a function of design parameters required for directly adapting layer rigidization technology to other applications. This paper presents a parametric design study of a new layer jamming vacuum rigidization architecture: tile-based vacuum rigidization. This form of rigidization is based on layers of tiles contained within a thin vacuum bladder which can be bent, rolled, or otherwise compactly stowed, but when deployed flat, can be vacuumed and form a large, flat, rigid plate capable of supporting large forces both localized and distributed over the surface. The general architecture and operation detailing rigidization and compliance mechanisms is introduced. To quantitatively characterize the rigidization behavior, prototypes rigidization surfaces are fabricated and an experimental technique is developed based on a 3-point bending test. Performance evaluation metrics are developed to describe the stiffness, load-bearing capacity, and internal slippage of tested prototypes. A set of experimental parametric studies are performed to better understand the impact of

ASPHERICAL SURFACES APPROXIMATION IN AUTOMATED DESIGN OF OPTICAL SYSTEMS

Directory of Open Access Journals (Sweden)

T. V. Ivanova

2015-07-01

Full Text Available Subject of Research. The paper deals with the problems of higher order aspherical surfaces approximation using different equation types. The objects of research are two types of equations for higher order aspherical surfaces description used in different software for optical systems design (SАRО, OPAL, ZEMAX, CODE-V, etc. and dependent on z-coordinate or on a radial coordinate on the surface. Conversion from one type of equations to another is considered in view of application in different software for optical systems design. Methods. The subject matter of the method lies in usage of mean square method approximation for recalculation of high-order aspherical surface. Iterative algorithm for recalculation is presented giving the possibility to recalculate coefficients for different types of equations with required accuracy. Recommendations are given for choosing recalculation parameters such as the number of result equation coefficients, the number of points for recalculation and point allocation on a surface. Main Results. Example of recalculation for aspherical surface and accuracy estimation, including result aberration comparison between initial surface and recalculated surface are presented. The example has shown that required accuracy of surface representation was obtained. Practical Relevance. This technique is usable for recalculation of higher order aspherical surfaces in various types of software for optical systems design and also for research of optimal higher order aspherical surfaces description.

Uniform lateral etching of tungsten in deep trenches utilizing reaction-limited NF3 plasma process

Science.gov (United States)

Kofuji, Naoyuki; Mori, Masahito; Nishida, Toshiaki

2017-06-01

The reaction-limited etching of tungsten (W) with NF3 plasma was performed in an attempt to achieve the uniform lateral etching of W in a deep trench, a capability required by manufacturing processes for three-dimensional NAND flash memory. Reaction-limited etching was found to be possible at high pressures without ion irradiation. An almost constant etching rate that showed no dependence on NF3 pressure was obtained. The effect of varying the wafer temperature was also examined. A higher wafer temperature reduced the threshold pressure for reaction-limited etching and also increased the etching rate in the reaction-limited region. Therefore, the control of the wafer temperature is crucial to controlling the etching amount by this method. We found that the uniform lateral etching of W was possible even in a deep trench where the F radical concentration was low.

The construction for remediation work of contaminated water at Fukushima Daiichi Nuclear Power Plant. Closure work of seawater piping trench and screen pump chamber

International Nuclear Information System (INIS)

Hibi, Yasuki; Yanai, Shuji; Nishikori, Kazumasa; Soma, Yu

2016-01-01

In the seawater piping trench of Fukushima Daiichi Nuclear Power Plant, highly contaminated water was stagnating, which flowed in from the reactor building and turbine building affected by the tsunami caused by the Tohoku Pacific Ocean Earthquake. Although the screen pump chamber, adjacent to the seawater piping trench, escaped from the inflow and retention of contaminated water, it was exposed to the leakage risk of contaminated water from the seawater piping trench. As measures against these conditions, the following emergency work was applied: (1) contaminated water replacement and removal operation based on the implantation of fillers into the seawater piping trench, and (2) closure operation of the screen pump chamber by implanting fillers into the screen pump chamber. In face of these operations, long-distance underwater flow special filler, high workable concrete, and underwater non-separation concrete were developed and used. The implantation of the long-distance underwater-flow special fillers into the seawater piping trench was successfully completed by filling to the tunnel top without gap and without water head difference, and by preventing the occurrence of movement or water path formation of the fillers in the initial curing process. Other fillers were also able to be implanted as planned. The leakage risk of contaminated water to the periphery could be suppressed to a large extent by this work. (A.O.)

Making an outreach movie -The Puerto Rico Trench: Exploring the deepest place in the Atlantic Ocean

Science.gov (United States)

ten Brink, J.; ten Brink, U. S.

2004-12-01

A new movie will be screened that describes the exploration of the Puerto Rico trench with a multibeam echosounder and its significance to scientific research and tsunami hazard assessment. The movie audience is the general public including high school students. It aims to stimulate interest in Oceanography and to demonstrate scientific processes as they are applied in Geological Oceanography. The extensive use of 3-D visualization fly-bys over the dramatic ocean floor of the Puerto Rico trench should be particularly appealing to a generation growing up on video games and 3-D visualizations. The film is the product of close cooperation between a film maker and a scientist through all stages of its production and post production. This level of close cooperation is necessary because scientists' and film makers' approaches to presentation of information can differ greatly. In making an educational or outreach movie, the scientist must be responsible for the contents of the message, but the film maker has to design an effective delivery method. The creation of this movie was the result of following stages: (1) live action filming during a short research cruise; (2) generating 3-D fly-by using Fledermausr software; (3) rendering the fly-by sequences to a high-definition film; (4) collecting still photos and other supporting material; (5) generating graphs illustrating crucial scientific information and concepts; (6) preparing the script for voiceover narration; (7) working with a professional actor in order to ensure accurate delivery of the information. The biggest challenge in making the movie was the editing stage when the different elements of the movie were put together, incorporating music and voiceover into an aesthetically pleasing, interesting, and above all, scientifically accurate and coherent movie. Post-editing steps included replication of the master copy, package design, and distribution. The movie was completed in several weeks on a modest budget, thanks

Draft Level 1 Remedial Investigation Work Plan: 316-3 waste disposal trenches

International Nuclear Information System (INIS)

1987-09-01

This work plan describes the work to be performed for the initial level of site characterization for the 316.3 Trenches at the Hanford Site. This initial site characterization effort will include a review of existing environmental contamination data for the 300 Area as well as collection and analysis of environmental samples to better characterize subsurface contamination at the site. 7 refs., 10 figs., 7 tabs

Variation in the electrical properties of 100 V/100 A rated mesh and stripe TDMOSFETs (trench double-diffused MOSFETs) for motor drive applications

International Nuclear Information System (INIS)

Na, Kyoung-Il; Kah, Dong-Ha; Kim, Sang-Gi; Koo, Jin-Gun; Kim, Jong-Dae; Yang, Yil-Suk; Lee, Jin-Ho

2012-01-01

The vertical power metal-oxide semiconductor field-effect transistors (MOSFETs) with deep trench structures are the most promising candidates to overcome the trade-off relationship between the ON-resistance (R ON ) and the blocking voltage (BV DS ). Especially, 100 V/100 A rated trench power MOSFETs are used in components of many power systems, such as motors and LED lighting drive ICs, DC-DC converters in electric vehicles, and so on. In this work, we studied variations of the electrical characteristics, such as threshold voltage (V TH ), BV DS , and drain current drivability, with p-well doping concentration via the SILVACO simulator. From simulation results, we found the BV DS and the drain current (I D ) as functions of the p-well doping concentration at an ion implantation energy of 80 keV. With increasing of p-well doping concentration in the guard ring region, both V TH and BV DS slowly increased, but I D decreased, because the boron lateral diffusion during the fabrication process below gate trench region affected the doping concentration of the p-body at the active region. Additionally, 100 V/100 A rated trench double-diffused MOSFETs (TDMOSFETs) with meshes and stripes were successfully developed by using a silicon deep etching process. The variations in the electrical properties, such as V TH , BV DS , and drain current drivability, of the two different kinds of fabricated devices, with cell design and density in TDMOSFETs were also studied. The BV DS and the V TH in the stripe-type TDMOSFET were 110 and 3 V, respectively. However, the V TH of mesh-type device was smaller 0.5 V than that of stripe-type because of corner effect. The BV DS improved about 20 V compared to stripe-type TDMOSFET due to edge termination, and the maximum drain current (I D.MAX ) was improved by about 10% due to an increase in the gate width at the same chip size. These effects were reflected in devices with different cell densities. When the cell density was increased, however

Computer-aided design of curved surfaces with automatic model generation

Science.gov (United States)

Staley, S. M.; Jerard, R. B.; White, P. R.

1980-01-01

The design and visualization of three-dimensional objects with curved surfaces have always been difficult. The paper given below describes a computer system which facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine which produces three-dimensional foam models. Thus, the system permits the designer to produce an inexpensive model of the object which is suitable for evaluation and presentation.

Optimized Design of Spacer in Electrodialyzer Using CFD Simulation Method

Science.gov (United States)

Jia, Yuxiang; Yan, Chunsheng; Chen, Lijun; Hu, Yangdong

2018-06-01

In this study, the effects of length-width ratio and diversion trench of the spacer on the fluid flow behavior in an electrodialyzer have been investigated through CFD simulation method. The relevant information, including the pressure drop, velocity vector distribution and shear stress distribution, demonstrates the importance of optimized design of the spacer in an electrodialysis process. The results show width of the diversion trench has a great effect on the fluid flow compared with length. Increase of the diversion trench width could strength the fluid flow, but also increase the pressure drop. Secondly, the dead zone of the fluid flow decreases with increase of length-width ratio of the spacer, but the pressure drop increases with the increase of length-width ratio of the spacer. So the appropriate length-width ratio of the space should be moderate.

Evaluation of the Location and Recency of Faulting Near Prospective Surface Facilities in Midway Valley, Nye County, Nevada

Science.gov (United States)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2001-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

Energy Technology Data Exchange (ETDEWEB)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-17

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

International Nuclear Information System (INIS)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Installation and instrumentation of a test-trench facility in the unsaturated zone at the Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Lewis, B.D.

1984-01-01

Two simulated waste trenches have been constructed just north of the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering Laboratory. Sections of culvert occupy part of these trenches and are accessible through vertical caissons. These structures therefore allow personnel access for installing instrumentation, maintenance, and observation. Instrumented simulated waste containers will occupy the remainder of the trenches, in order that soil-moisture migration may be observed in relation to waste container forms. The installation will be used to determine, under actual and simulated conditions at a shallow land-burial site in an arid environment, typical soil-moisture content, unsaturated hydraulic conductivity, matric potential, soil-moisture flux, and soil-moisture velocity. The information will be collected using instrumentation located in disturbed and undisturbed soils, simulated waste containers, and the underlying basalt layer. Therefore, data collected from the facility will (a) help characterize the hydrogeologic and geochemical properties of the surficial sediments, (b) contribute to understanding the hydrogeologic phenomena associated with buried waste (including leachate formation and radionuclide migration), (c) provide information on water and solute movement at the sediment/basalt interface, and (d) be used in a radionuclide migration model

Optical description and design method with annularly stitched aspheric surface.

Science.gov (United States)

Cheng, De-Wen; Chen, Xue-Jiao; Xu, Chen; Hu, Yuan; Wang, Yong-Tian

2015-12-01

The relentless pressure for designs with new optical functions, small volume, and light weight has greatly increased the importance of aspheric surfaces. In this paper, we propose an annularly stitched aspheric surface (ASAS) description method to increase the freedom and flexibility of imaging system design. The rotationally symmetric ASAS consists of a circular central zone and one or more annular zones. Two neighboring zones are constrained to have the same derivatives on their joint curve, and this means the ASAS is C1 continuous. This finding is proved and verified by the mathematical deduction of the surface formulas. Two optimization strategies and two design methods with the C1 continuous constraints are also discussed. This surface can greatly facilitate the design and even achieve some previously impossible designs without increasing the fabrication difficulty. Two different systems with the proposed ASAS are optimized and the results are presented. The design results verified the practicability of the ASAS.

Evaluating potential chlorinated methanes degradation mechanisms and treatments in interception trenches filled with concrete-based construction wastes

Science.gov (United States)

Rodríguez-Fernandez, Diana; Torrentó, Clara; Rosell, Mònica; Audí-Miró, Carme; Soler, Albert

2014-05-01

A complex mixture of chlorinated organic compounds is located in an unconfined carbonated bedrock aquifer with low permeability in a former industrial area next to Barcelona (NE Spain). The site exhibited an especially high complexity due to the presence of multiple contaminant sources, wide variety of pollutants (mainly chlorinated ethenes but also chlorinated methanes) and unknown system of fractures (Palau et al., 2014). Interception trenches were installed in the place of the removed pollution sources and were filled with construction wastes with the aim of retaining and treating the accumulated contaminated recharge water before reaching the aquifer. Recycled concrete-based aggregates from a construction and demolition waste recycling plant were used to maintain alkaline conditions in the water accumulated in the trenches (pH 11.6±0.3) and thus induce chloroform (CF) degradation by alkaline hydrolysis. An efficacy of around 30-40% CF degradation in the interception trenches was calculated from the significant and reproducible CF carbon isotopic fractionation (-53±3o obtained in batch experiments (Torrentó et al., 2014). Surprisingly, although hydrolysis of carbon tetrachloride (CT) is extremely slow, a significant CT carbon isotopic enrichment was also observed in the trenches. The laboratory experiments verified the low capability of concrete to hydrolyze the CT and showed the high adsorption of CT on the concrete particles (73% after 50 days) with invariability in its δ13C values. Therefore, the significant CT isotopic fractionation observed in the interception trenches could point out the occurrence of other degradation processes distinct than alkaline hydrolysis. Geochemical speciation modelling using the code PHREEQC showed that water collected at the trenches is supersaturated with respect to several iron oxy-hydroxides and therefore, CT degradation processes related to these iron minerals cannot be discarded. In addition, the combination of alkaline

Subduction of a buoyant plateau at the Manila Trench: Tomographic evidence and geodynamic implications

Science.gov (United States)

Fan, Jianke; Zhao, Dapeng; Dong, Dongdong

2016-02-01

We determined P-wave tomographic images by inverting a large number of arrival-time data from 2749 local earthquakes and 1462 teleseismic events, which are used to depict the three-dimensional morphology of the subducted Eurasian Plate along the northern segment of the Manila Trench. Dramatic changes in the dip angle of the subducted Eurasian Plate are revealed from the north to the south, being consistent with the partial subduction of a buoyant plateau beneath the Luzon Arc. Slab tears may exist along the edges of the buoyant plateau within the subducted plate induced by the plateau subduction, and the subducted lithosphere may be absent at depths greater than 250 km at ˜19°N and ˜21°N. The subducted buoyant plateau is possibly oriented toward NW-SE, and the subducted plate at ˜21°N is slightly steeper than that at ˜19°N. These results may explain why the western and eastern volcanic chains in the Luzon Arc are separated by ˜50 km at ˜18°N, whereas they converge into a single volcanic chain northward, which may be related to the oblique subduction along the Manila Trench caused by the northwestern movement of the Philippine Sea Plate. A low-velocity zone is revealed at depths of 20-200 km beneath the Manila Accretionary Prism at ˜22°N, suggesting that the subduction along the Manila Trench may stop there and the collision develops northward. The Taiwan Orogeny may originate directly from the subduction of the buoyant plateau, because the initial time of the Taiwan Orogeny is coincident with that of the buoyant plateau subduction.

Remedial action technology - arid

International Nuclear Information System (INIS)

Hakonson, T.E.; DePoorter, G.L.; Nyhan, J.W.; Perkins, B.A.; Lane, L.J.

1982-01-01

A summary is presented of the low-level waste remedial action program at Los Alamos. The experimental design and progress is described for the experiments on second generation intrusion barriers, subsidence effects on SLB components, moisture cycling effects on chemical transport, and erosion control methodologies. The soil moisture data from the bio-intrusion and moisture cycling experiments both demonstrate the overwhelming importance of vegetation in minimizing infiltration of water through trench covers and backfill. Evaporation, as a water loss component in trench covers, is only effective in reducing soil moisture within 40 cm of the trench cover surface. Moisture infiltrating past the zone of evaporation in unvegetated or poorly vegetated trench covers is in storage and accumulates until drainage out of the soil profile occurs. Judicious selection of vegetation species for revegetating a low-level waste site may prevent infiltration of moisture into the trench and, when coupled with other design features (i.e. trench cover slope, tilling and seeding practice), may greatly reduce problems with erosion. Standard US Department of Agriculture erosion plots, when coupled with a state-of-the-art water balance and erosion model (CREAMS) promises to be highly useful in screening proposed remedial action cover designs for low-level waste sites. The erosion plot configuration allows for complete accounting of the water balance in a soil profile. This feature enables the user to optimize cover designs to minimize erosion and infiltration of water into the trench

Interpretation of vadose zone monitoring system data near Engineered Trench 1

Energy Technology Data Exchange (ETDEWEB)

Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Whiteside, T. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-12-12

The E-Area Vadose Zone Monitoring System (VZMS) includes lysimeter sampling points at many locations alongside and angling beneath the Engineered Trench #1 (ET1) disposal unit footprint. The sampling points for ET1 were selected for this study because collectively they showed consistently higher tritium (H-3) concentrations than lysimeters associated with other trench units. The VZMS tritium dataset for ET1 from 2001 through 2015 comprises concentrations at or near background levels at approximately half of locations through time, concentrations up to about 600 pCi/mL at a few locations, and concentrations at two locations that have exceeded 1000 pCi/mL. The highest three values through 2015 were 6472 pCi/mL in 2014 and 4533 pCi/mL in 2013 at location VL-17, and 3152 pCi/mL in 2007 at location VL-15. As a point of reference, the drinking water standard for tritium and a DOE Order 435.1 performance objective in the saturated zone at the distant 100-meter facility perimeter is 20 pCi/mL. The purpose of this study is to assess whether these elevated concentrations are indicative of a general trend that could challenge 2008 E-Area Performance Assessment (PA) conclusions, or are isolated perturbations that when considered in the context of an entire disposal unit would support PA conclusions.

Disposal project for LLW and VLLW generated from research facilities in Japan: A feasibility study for the near surface disposal of VLLW that includes uranium

International Nuclear Information System (INIS)

Sakai, Akihiro; Hasegawa, M.; Sakamoto, Y.; Nakatani, T.

2016-01-01

Conclusion and future work: • JAEA plans trench disposal of U-bearing waste with less than 100 Bq/g. • Two safety measures of trench disposal of U-bearing waste have been discussed taking into account increasing radioactivity over a long period of time. 1. First is to carry out dose assessment of site use scenario by using a conservatively stylized condition. 2. Second is to control the average concentration of U in the trench facilities based on the concept of the existing exposure situation. • We are continuously developing the method for safety measures of near surface disposal of VLLW including U-bearing waste.

AMS measurement of {sup 10}Be concentrations in marine sediments from Chile Trench at the TANDAR laboratory

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, D., E-mail: darodrig@tandar.cnea.gov.ar [Departamento de Física Experimental, Laboratorio TANDAR, GIyA, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA San Martín (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Arazi, A. [Departamento de Física Experimental, Laboratorio TANDAR, GIyA, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA San Martín (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Fernández Niello, J.O. [Departamento de Física Experimental, Laboratorio TANDAR, GIyA, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA San Martín (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Instituto de Investigación e Ingeniería Ambiental, Universidad Nacional de San Martín, 25 de Mayo y Francia, B1650BWA San Martín, Buenos Aires (Argentina); Martí, G.V. [Departamento de Física Experimental, Laboratorio TANDAR, GIyA, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA San Martín (Argentina); and others

2017-03-15

The {sup 10}Be/{sup 9}Be ratios in marine sediments samples from the Southern Chile Trench have been measured using accelerator mass spectrometry (AMS). The samples were measured at the TANDAR accelerator, where the discrimination of the {sup 10}Be radionuclides was achieved by means of a passive absorber in front of an ionization chamber. This setup along with the high voltage available, provided a complete suppression of the {sup 10}B isobar interference. The obtained values for the {sup 10}Be concentrations, of the order of 10{sup 9} atoms/g, are the first {sup 10}Be measurements from the Southern Chile Trench and offer an excellent tracer to quantitatively study the recycling of sediments in Andean magmas.

Mathematical modeling in low-level radioactive waste management

International Nuclear Information System (INIS)

Ward, D.S.; Yeh, G.T.

1978-01-01

Mathematical modeling of moisture transport through near-surface infiltration reduction seals above low-level waste trenches may be used to aid in the evaluation of engineering design alternatives. The infiltration of rainwater must be reduced for successful radionuclide containment within a typical shallow trench. Clay admixtures offer not only long-term integrity, but the necessary durability. The use of models is exemplified in the calculation of spatial moisture content and velocity distributions in the vicinity of a near-surface seal

The role of geophysical ERT method to evaluate the leakproofness of diapragm wall of deep foundation trenches on the example of the construction of retail and office complex in Lublin, Poland

Directory of Open Access Journals (Sweden)

Pacanowski Grzegorz

2014-12-01

Full Text Available This paper addresses the problem of assessing the leakproofness of the bottom of a deep foundation trench, secured by cavity wall, using geophysical methods of electrical resistivity tomography. The study was conducted on a large construction project in Lublin, in a place where there are complicated soil-water conditions: the groundwater level is above the proposed depth of foundation trench, the subsoil is heterogeneous, and there are karsted and weathered carbonate sediments with confined aquifer below the bottom of the trench. A hydraulic fracture occurred at the bottom of the trench during the engineering works, which caused the water flow into the trench. In order to recognize the soil-water conditions the first stage of geophysical measurements of electrical resistivity tomography (ERT was made. The applied methodology allowed to determine the extent of the hydraulic fracture zone within the bottom of foundation trench. In order to assess the leakproofness of Diaphragm Wall the geophysical ERT measurements were repeated (stage 2 A clear reduction in the value of the electrical resistivity of soils in the area of hydraulic fracture was caused by clay injection. The results of ERT measurements are discussed and graphically presented.

Sikorsky interactive graphics surface design/manufacturing system

Science.gov (United States)

Robbins, R.

1975-01-01

An interactive graphics system conceived to be used in the design, analysis, and manufacturing of aircraft components with free form surfaces was described. In addition to the basic surface definition and viewing capabilities inherent in such a system, numerous other features are present: surface editing, automated smoothing of control curves, variable milling patch boundary definitions, surface intersection definition and viewing, automatic creation of true offset surfaces, digitizer and drafting machine interfaces, and cutter path optimization. Documented costs and time savings of better than six to one are being realized with this system. The system was written in FORTRAN and GSP for use on IBM 2250 CRT's in conjunction with an IBM 370/158 computer.

Surface Plasmon Wave Adapter Designed with Transformation Optics

DEFF Research Database (Denmark)

Zhang, Jingjing; Xiao, Sanshui; Wubs, Martijn

2011-01-01

On the basis of transformation optics, we propose the design of a surface plasmon wave adapter which confines surface plasmon waves on non-uniform metal surfaces and enables adiabatic mode transformation of surface plasmon polaritons with very short tapers. This adapter can be simply achieved...... with homogeneous anisotropic naturally occurring materials or subwavelength grating-structured dielectric materials. Full wave simulations based on a finite-element method have been performed to validate our proposal....

300 Area Process Trenches Postclosure Plan

International Nuclear Information System (INIS)

Badden, J.W.

1998-05-01

The 300 Area Process Trenches (300 APT) certified closure under a modified closure option and in compliance with Condition II.K.3 oft he Hartford Facility Dangerous Waste Permit (Penit) (Ecology 1994). Modified closure has been determined to be the appropriate closure option for this unit due to groundwater that remains contaminated from past operations at the 300 APT. Corrective actions required for dangerous waste constituents remaining in groundwater will occur pursuant to the 300 APT Resource Conservation and Recovery Act (RCRA) Final Status Facility Ground Water Monitoring Plan, the Hanford Site Wide Dangerous Waste Permit, and in conjunction with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial actions at the 300-FF-5 Groundwater Operable Unit (OU) pursuant to the Record of Decision (ROD) (EPA 1996). This postclosure plan identifies the modified closure actions required at the unit under postclosure care. It contains a description of the unit, past closure actions, and postclosure care requirements subject to compliance under the Permit (condition II.K.3)

Initial formulation results for in situ grouting of a waste trench at ORNL Site No. 6

International Nuclear Information System (INIS)

Tallent, O.K.; McDaniel, E.W.; Spence, R.D.; Godsey, T.T.

1987-01-01

An investigation is being conducted by the Chemical Technology Division to assist the Environmental Sciences Division in developing a grout formulation for use in testing in situ grouting in a waste trench at ORNL Site 6. This final report satisfies the milestone of Subtack 12 entitled, ''Low Level Waste (LLW) Trench Grouting Assessment,'' which was initially issued as RAP-86-7, December 31, 1985. Grouts prepared from dry-solid blends containing Type I Portland cement, ASTM Class C or Class F fly ash, and bentonite, mixed water at ratios of 10 to 15 lb/gal, were evaluated. The grouts prepared with ASTM Class C fly ash exhibited significantly better properties than those prepared with ASTM Class F fly ash. The grouts containing ASTM Class C fly ash satisfy tentative performance criteria for the project. 8 refs., 7 tabs

Corrective Action Investigation Plan for Corrective Action Unit 410: Waste Disposal Trenches, Tonopah Test Range, Nevada, Revision 0 (includes ROTCs 1, 2, and 3)

Energy Technology Data Exchange (ETDEWEB)

NNSA/NV

2002-07-16

This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 410 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 410 is located on the Tonopah Test Range (TTR), which is included in the Nevada Test and Training Range (formerly the Nellis Air Force Range) approximately 140 miles northwest of Las Vegas, Nevada. This CAU is comprised of five Corrective Action Sites (CASs): TA-19-002-TAB2, Debris Mound; TA-21-003-TANL, Disposal Trench; TA-21-002-TAAL, Disposal Trench; 09-21-001-TA09, Disposal Trenches; 03-19-001, Waste Disposal Site. This CAU is being investigated because contaminants may be present in concentrations that could potentially pose a threat to human health and/or the environment, and waste may have been disposed of with out appropriate controls. Four out of five of these CASs are the result of weapons testing and disposal activities at the TTR, and they are grouped together for site closure based on the similarity of the sites (waste disposal sites and trenches). The fifth CAS, CAS 03-19-001, is a hydrocarbon spill related to activities in the area. This site is grouped with this CAU because of the location (TTR). Based on historical documentation and process know-ledge, vertical and lateral migration routes are possible for all CASs. Migration of contaminants may have occurred through transport by infiltration of precipitation through surface soil which serves as a driving force for downward migration of contaminants. Land-use scenarios limit future use of these CASs to industrial activities. The suspected contaminants of potential concern which have been identified are volatile organic compounds; semivolatile organic compounds; high explosives; radiological constituents including depleted

Biological intrusion of low-level-waste trench covers

Science.gov (United States)

Hakonson, T. E.; Gladney, E. S.

The long-term integrity of low-level waste shallow land burialsites is dependent on the interaction of physical, chemical, and biological factors that modify the waste containment system. The need to consider biological processes as being potentially important in reducing the integrity of waste burial site cover treatment is demonstrated. One approach to limiting biological intrusion through the waste cover is to apply a barrier within the profile to limit root and animal penetration with depth. Experiments in the Los Alamos Experimental Engineered Test Facility were initiated to develop and evaluate biological barriers that are effective in minimizing intrusion into waste trenches. The experiments that are described employ four different candidate barrier materials of geologic origin. Experimental variables that will be evaluated, in addition to barrier type, are barrier depth and sil overburden depth.

Evaluation of Surface and Subsurface Processes in Permeable Pavement Infiltration Trenches

Science.gov (United States)

The hydrologic performance of permeable pavement systems can be affected by clogging of the pavement surface and/or clogging at the interface where the subsurface storage layer meets the underlying soil. As infiltration and exfiltration are the primary functional mechanisms for ...

Repository surface design site layout analysis

International Nuclear Information System (INIS)

Montalvo, H.R.

1998-01-01

The purpose of this analysis is to establish the arrangement of the Yucca Mountain Repository surface facilities and features near the North Portal. The analysis updates and expands the North Portal area site layout concept presented in the ACD, including changes to reflect the resizing of the Waste Handling Building (WHB), Waste Treatment Building (WTB), Carrier Preparation Building (CPB), and site parking areas; the addition of the Carrier Washdown Buildings (CWBs); the elimination of the Cask Maintenance Facility (CMF); and the development of a concept for site grading and flood control. The analysis also establishes the layout of the surface features (e.g., roads and utilities) that connect all the repository surface areas (North Portal Operations Area, South Portal Development Operations Area, Emplacement Shaft Surface Operations Area, and Development Shaft Surface Operations Area) and locates an area for a potential lag storage facility. Details of South Portal and shaft layouts will be covered in separate design analyses. The objective of this analysis is to provide a suitable level of design for the Viability Assessment (VA). The analysis was revised to incorporate additional material developed since the issuance of Revision 01. This material includes safeguards and security input, utility system input (size and location of fire water tanks and pump houses, potable water and sanitary sewage rates, size of wastewater evaporation pond, size and location of the utility building, size of the bulk fuel storage tank, and size and location of other exterior process equipment), main electrical substation information, redundancy of water supply and storage for the fire support system, and additional information on the storm water retention pond

Lightweight hull surface self-design vertical parameterization method based on NURBS

Directory of Open Access Journals (Sweden)

ZHANG Yanru

2017-10-01

Full Text Available [Objectives] At present, conventional design is limited to parent ship design space, and cannot drive ship hull design using as few parameters as possible. In order to solve the above problems, [Methods] by combining the draught function with NURBS, a ship hull surface self-design method based on vertical parameterization is proposed. In this method, the waterline is designated as the basic design unit; the bottom flat end line, designed waterline, stem and stern contours, side flat end line and maximum section line are designated as the characteristic constraints of the ship hull; and the draught function values corresponding to the characteristic parameters are designated as the design objectives. In this way, a waterline approximation model is built, and an evolutionary algorithm can be used to solve the approximation model. Finally, the ship hull surface is generated on the basis of the waterline using the NURBS skinning technique.[Results] The design examples of the characteristic curves of the full-scale ship hull surface indicate the practicable and advanced nature of this method.[Conclusions] The hull surface can be designed with as little data as possible using this method, making it much more suitable for the self-design of new ship forms.

Closure Report for Corrective Action Unit 404: Roller Coaster Sewage Lagoons and North Disposal Trench, Tonopah Test Range, Nevada with ROTC 1, Revision 0

Energy Technology Data Exchange (ETDEWEB)

Lynn Kidman

1998-09-01

This Closure Report provides the documentation for closure of the Roller Coaster Sewage Lagoons and North Disposal Trench Comective Action Unit (CAU) 404. CAU 404 consists of the Roller Coaster Sewage Lagoons (Corrective Action Site [CAS] TA-03-O01-TA-RC) and the North Disposal Trench (CAS TA-21-001-TA-RC). The site is located on the Tonopah Test Range, approximately 225 kilometers (km) (140 miles [mi]) northwest ofLas Vegas, Nevada. . The sewage lagoons received ~quid sanitary waste horn the Operation Roller Coaster Man Camp in 1963 and debris from subsequent range and construction cleanup activities. The debris and ordnance was subsequently removed and properly dispos~, however, pesticides were detected in soil samples born the bottom of the lagoons above the U,S. Environmental Protection Agency Region IX Prelimimuy Remediation Goals (EPA 1996). . The North Disposal Trench was excavated in 1963. Debris from the man camp and subsequent range and construction cleanup activities was placed in the trench. Investigation results indicated that no constituents of concern were detected in soil samples collected from the trench. Remedial alternative proposed in the Comctive Action Decision Document (CADD) fm the site was “Covering” (DOE, 1997a). The Nevada Division of”Enviromnental Protection (NDEP)-approved Correction Action Plan (CAP) proposed the “Covering” niethodology (1997b). The closure activities were completed in accorhce with the approwil CAP and consisted of baclctllling the sewage lagoons and disposal trench, constructing/planting an engineered/vegetative cover in the area of the sewage lagoons and dikposal trencQ installing a perimeter fence and signs, implementing restrictions on fi~e use, and preparing a Post-Closure Monitoring Plan. “ Since closure activities. for CAU 404 have been completed in accordance with the Nevada Division of Environmental Protection-approved CAP (DOE, 1997b) as documented in this Closure Report, the U.S. Department of

Surface design methodology – challenge the steel

International Nuclear Information System (INIS)

Bergman, M; Rosen, B-G; Eriksson, L; Anderberg, C

2014-01-01

The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or ''feeling'' for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA

Inverse design of nanostructured surfaces for color effects

DEFF Research Database (Denmark)

Andkjær, Jacob Anders; Johansen, Villads Egede; Friis, Kasper Storgaard

2014-01-01

We propose an inverse design methodology for systematic design of nanostructured surfaces for color effects. The methodology is based on a 2D topology optimization formulation based on frequency-domain finite element simulations for E and/or H polarized waves. The goal of the optimization...... is to maximize color intensity in prescribed direction(s) for a prescribed color (RGB) vector. Results indicate that nanostructured surfaces with any desirable color vector can be generated; that complex structures can generate more intense colors than simple layerings; that angle independent colorings can...

Design of a solar concentrator considering arbitrary surfaces

Science.gov (United States)

Jiménez-Rodríguez, Martín.; Avendaño-Alejo, Maximino; Verduzco-Grajeda, Lidia Elizabeth; Martínez-Enríquez, Arturo I.; García-Díaz, Reyes; Díaz-Uribe, Rufino

2017-10-01

We study the propagation of light in order to efficiently redirect the reflected light on photocatalytic samples placed inside a commercial solar simulator, and we have designed a small-scale prototype of Cycloidal Collectors (CCs), resembling a compound parabolic collector. The prototype consists of either cycloidal trough or cycloidal collector having symmetry of rotation, which has been designed considering an exact ray tracing assuming a bundle of rays propagating parallel to the optical axis and impinging on a curate cycloidal surface, obtaining its caustic surface produced by reflection.

Variation in the electrical properties of 100 V/100 A rated mesh and stripe TDMOSFETs (trench double-diffused MOSFETs) for motor drive applications

Energy Technology Data Exchange (ETDEWEB)

Na, Kyoung-Il; Kah, Dong-Ha; Kim, Sang-Gi; Koo, Jin-Gun; Kim, Jong-Dae; Yang, Yil-Suk; Lee, Jin-Ho [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of)

2012-05-15

The vertical power metal-oxide semiconductor field-effect transistors (MOSFETs) with deep trench structures are the most promising candidates to overcome the trade-off relationship between the ON-resistance (R{sub ON}) and the blocking voltage (BV{sub DS}). Especially, 100 V/100 A rated trench power MOSFETs are used in components of many power systems, such as motors and LED lighting drive ICs, DC-DC converters in electric vehicles, and so on. In this work, we studied variations of the electrical characteristics, such as threshold voltage (V{sub TH}), BV{sub DS}, and drain current drivability, with p-well doping concentration via the SILVACO simulator. From simulation results, we found the BV{sub DS} and the drain current (I{sub D}) as functions of the p-well doping concentration at an ion implantation energy of 80 keV. With increasing of p-well doping concentration in the guard ring region, both V{sub TH} and BV{sub DS} slowly increased, but I{sub D} decreased, because the boron lateral diffusion during the fabrication process below gate trench region affected the doping concentration of the p-body at the active region. Additionally, 100 V/100 A rated trench double-diffused MOSFETs (TDMOSFETs) with meshes and stripes were successfully developed by using a silicon deep etching process. The variations in the electrical properties, such as V{sub TH}, BV{sub DS}, and drain current drivability, of the two different kinds of fabricated devices, with cell design and density in TDMOSFETs were also studied. The BV{sub DS} and the V{sub TH} in the stripe-type TDMOSFET were 110 and 3 V, respectively. However, the V{sub TH} of mesh-type device was smaller 0.5 V than that of stripe-type because of corner effect. The BV{sub DS} improved about 20 V compared to stripe-type TDMOSFET due to edge termination, and the maximum drain current (I{sub D.MAX}) was improved by about 10% due to an increase in the gate width at the same chip size. These effects were reflected in devices with

Ship motion effects in CTD-data from weakly stratified waters of the Puerto Rico trench

NARCIS (Netherlands)

van Haren, H.

2015-01-01

Shipborne SBE 911plus Conductivity Temperature Depth (CTD)-casts have been made to maximum 7220 m in the Puerto Rico Trench (PRT). In PRT-waters from 5500 m and deeper and specifically below the 6500 m transition to the hadal-zone, the vertical density stratification is found very weak, with

Midinfrared Surface Waves on a High Aspect Ratio Nanotrench Platform

DEFF Research Database (Denmark)

Takayama, Osamu; Shkondin, Evgeniy; Bodganov, Andrey

2017-01-01

ameliorate surface wave propagation and even generate new types of waves. Here, we demonstrate that high aspect ratio (1:20) grating structures with plasmonic lamellas in deep nanoscale trenches, whose pitch is 1/10 – 1/35 of a wavelength, function as a versatile platform supporting both surface and guided...... bulk infrared waves. The surface waves exhibit a unique combination of properties: directionality, broadband existence (from 4 µm to at least 14 μm and beyond) and high localization, making them an attractive tool for effective control of light in an extended range of infrared frequencies....

Design of Surface micromachined Compliant MEMS

Energy Technology Data Exchange (ETDEWEB)

Bradley, Joe Anthony [Iowa State Univ., Ames, IA (United States)

2001-01-01

The consideration of compliant mechanisms as Microelectromechanical Systems (MEMS) is the focus of this research endeavor. MEMS are micron to millimeter devices that combine electrical, mechanical, and information processing capabilities on the same device. These MEMS need some mechanical motion or parts that move relative to each other. This relative motion, using multiple parts, is not desired because of the assembly requirement and the friction introduced. Compliant devices limits or eliminates friction and the need for multi-component assembly. Compliant devices improve designs by creating single piece mechanisms. The purpose of this research is to validate surface micromachining as a viable fabrication process for compliant MEMS designs. Specifically, this research has sought to fabricate a micro-compliant gripper and a micro-compliant clamp to illustrate the process. While other researchers have created compliant MEMS, most have used comb-drive actuation methods and bulk micromachining processes. This research focuses on fully-compliant devices that use device flexibility for motion and actuation. Validation of these compliant MEMS is achieved by structural optimization of device design and functional performance testing. This research contributes to the ongoing research in MEMS by evaluating the potential of using surface micromachining as a process for fabricating compliant micro-mechanisms.

Design of Surface Micromachined Compliant MEMS

Energy Technology Data Exchange (ETDEWEB)

Bradley, Joe Anthony [Iowa State Univ., Ames, IA (United States)

2002-12-31

The consideration of compliant mechanisms as Microelectromechanical Systems (MEMS) is the focus of this research endeavor. MEMS are micron to millimeter devices that combine electrical, mechanical, and information processing capabilities on the same device. These MEMS need some mechanical motion or parts that move relative to each other. This relative motion, using multiple parts, is not desired because of the assembly requirement and the friction introduced. Compliant devices limits or eliminates friction and the need for multi-component assembly. Compliant devices improve designs by creating single piece mechanisms. The purpose of this research is to validate surface micromachining as a viable fabrication process for compliant MEMS designs. Specifically, this research has sought to fabricate a micro-compliant gripper and a micro-compliant clamp to illustrate the process. While other researchers have created compliant MEMs, most have used comb-drive actuation methods and bulk micromachining processes. This research focused on fully-compliant devices that use device flexibility for motion and actuation. Validation of these compliant MEMS is achieved by structural optimization of device design and functional performance testing. This research contributes to the ongoing research in MEMS by evaluating the potential of using surface micromachining as a process for fabricating compliant micro-mechanisms.

Comparison of optical design methods of freeform surfaces for imaging applications

Science.gov (United States)

Agócs, Tibor

2015-09-01

Optical systems based on freeform optical components offer many advantages over conventional systems in imaging applications, e.g. superior image quality, compact and lightweight designs. There are a few well established manufacturing method that can be used for the generation of freeform surfaces with low surface form error and low surface roughness, in the case of freeform mirrors e.g. diamond turning, nickel plating and post-polishing. Metrology is evolving rapidly, although developments are still needed in order to verify the manufactured surface with the necessary accuracy. Optical design methods of freeform surfaces are also lagging behind, many algorithms address non-imaging applications, but in the field of imaging (image-forming) only a few exists and works with various limitations. We compare the available techniques in freeform optical design for imaging and explore the advantages, disadvantages and boundary conditions of the different methods. We also intend to identify the most useful concepts and investigate how they can be embedded into commercially available optical design software.

THE BC CRIBS and TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT: ONE STEP FORWARD IN HANFORD'S CLEANUP PROCESS

International Nuclear Information System (INIS)

BENECKE, M.W.

2005-01-01

A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50-acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity. and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy

Design Application Translates 2-D Graphics to 3-D Surfaces

Science.gov (United States)

2007-01-01

Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research Center. This template or pattern is then applied in the development of a 2-D graphic layout. Benefits of this process include 11.5 percent time savings per project, less material wasted, and the ability to improve upon graphic techniques and offer new design services. Partners include Exhibitgroup/Giltspur (end-user client: TAC Air, a division of Truman Arnold Companies Inc.), Jack Morton Worldwide (end-user client: Nickelodeon), as well as 3D Exhibits Inc., and MG Design Associates Corp.

Recent sediment dynamics in hadal trenches: Evidence for the influence of higher-frequency (tidal, near-inertial) fluid dynamics

DEFF Research Database (Denmark)

Turnewitsch, Robert; Falahat, Saeed; Stehlikova, Jirina

2014-01-01

finds evidence for another mechanism that is superimposed on, and counteracts, the focussing mechanism. This superimposed mechanism is related to higher-frequency (tidal, near-inertial) fluid dynamics. In particular, there is evidence for a strong and negative relation between the intensity...... but significant influence on particulate-matter dynamics and food supply in hadal trenches in particular, but possibly also in the deep seas in general. A mechanism for the influence of internal tides on sediment dynamics is proposed. (C) 2014 Elsevier Ltd. All rights reserved.......In addition to high hydrostatic pressure, scarcity of food is viewed as a factor that limits the abundance and activity of heterotrophic organisms at great ocean depths, including hadal trenches. Supply of nutritious food largely relies on the flux of organic-rich particulate matter from...

Modeling Replenishment of Ultrathin Liquid Perfluoro polyether Z Films on Solid Surfaces Using Monte Carlo Simulation

International Nuclear Information System (INIS)

Mayeed, M.S.; Kato, T.

2014-01-01

Applying the reptation algorithm to a simplified perfluoro polyether Z off-lattice polymer model an NVT Monte Carlo simulation has been performed. Bulk condition has been simulated first to compare the average radius of gyration with the bulk experimental results. Then the model is tested for its ability to describe dynamics. After this, it is applied to observe the replenishment of nano scale ultrathin liquid films on solid flat carbon surfaces. The replenishment rate for trenches of different widths (8, 12, and 16 nms for several molecular weights) between two films of perfluoro polyether Z from the Monte Carlo simulation is compared to that obtained solving the diffusion equation using the experimental diffusion coefficients of Ma et al. (1999), with room condition in both cases. Replenishment per Monte Carlo cycle seems to be a constant multiple of replenishment per second at least up to 2 nm replenished film thickness of the trenches over the carbon surface. Considerable good agreement has been achieved here between the experimental results and the dynamics of molecules using reptation moves in the ultrathin liquid films on solid surfaces.

Repository Surface Design Engineering Files Report Rev 00 ICN 1

International Nuclear Information System (INIS)

2001-01-01

The objective of the Repository Surface Design Engineering Files Report Supplement [herein known as the Engineering Files (EF)] is to provide the surface design data needed by the Environmental Impact Statement (EIS) contractor to prepare the EIS and evaluate options and alternatives. This document is based on the Repository Surface Design Engineering Files Report, Revision 03 (CRWMS M and O 1999f) (EF Rev 03). Where facility and system designs have been changed for the Site Recommendation (SR) effort they are described in this report. EIS information provided in this report includes the following: (1) Description of program phases; there are no changes that impact this report. (2) A description of the major design requirements and assumptions that drive the surface facilities reference design is provided herein (Section 2.2), including the surface design resulting from recommendations regarding Enhanced Design Alternative (EDA) II, as discussed in the License Application Design Section Report (CRWMS M and O 1999d), and changes to the waste stream. See Section 2, Table 2-2, for the SR waste stream. (3) The major design requirements and assumptions that drive the surface facilities reference design are by reference to EF Rev 03; there are no changes that impact this report. (4) Description of the reference design concept and existing site conditions is by reference to EF Rev 03 (including Table 4-1, which is not included in this supplement); there are no changes that impact this report. (5) Description of alternative design cases is by reference to EF Rev 03; there are no changes that impact this report. (6) Description of optional inventory modules is by reference to EF Rev 03; there are no changes that impact this report. (7) Tabular summary level engineering values (i.e., staffing, wastes, emissions, resources, and land use) for the reference design and the alternative design cases that address construction, emplacement operations, caretaker operations, and

Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

International Nuclear Information System (INIS)

Gaschott, L.J.

1995-01-01

This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility

Correlation of surface contour, optoelectronic and spectroscopic properties of Cu(In,Ga)Se{sub 2} by SNOM and AFM

Energy Technology Data Exchange (ETDEWEB)

Neumann, Oliver; Heise, Stephan J.; Brueggemann, Rudolf; Meessen, Max; Bauer, Gottfried H. [Institute of Physics, Carl von Ossietzky University Oldenburg (Germany); Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany)

2012-07-01

Chalcopyrite absorbers exhibit local fluctuations of structural, optical and optoelectronic properties. We study the correlation of the surface contour and the local properties such as the integrated photoluminescence (PL) yield and the splitting of the quasi-Fermi levels in a Cu(In,Ga)Se{sub 2}-based thin-film system at room temperature by AFM and spatially resolved PL measurements at the identical position with a scanning near-field optical microscope (SNOM). The Cu(In,Ga)Se{sub 2} layer is deposited on glass, etched with bromine-methanol to smooth the surface for a more homogeneous incoupling of laser light, and passivated with cadmium sulfide. Our measurements reveal a high structural correlation between surface contour, integrated PL yield and quasi-Fermi level splitting. Additionally, we observe trenches in the surface contour which correspond to a dip or to a peak in the splitting of the quasi-Fermi levels and integrated PL yield. Furthermore some trenches show spectral variation of the PL compared to their direct environment. We discuss these observations with respect to the optoelectronic property and the composition of the absorber.

Modeling the Geometry of Plate Boundary and Seismic Structure in the Southern Ryukyu Trench Subduction Zone, Japan, Using Amphibious Seismic Observations

Science.gov (United States)

Yamamoto, Y.; Takahashi, T.; Ishihara, Y.; Kaiho, Y.; Arai, R.; Obana, K.; Nakanishi, A.; Miura, S.; Kodaira, S.; Kaneda, Y.

2018-02-01

Here we present the new model, the geometry of the subducted Philippine Sea Plate interface beneath the southern Ryukyu Trench subduction zone, estimated from seismic tomography and focal mechanism estimation by using passive and active data from a temporary amphibious seismic network and permanent land stations. Using relocated low-angle thrust-type earthquakes, repeating earthquakes, and structural information, we constrained the geometry of plate boundary from the trench axis to a 60 km depth with uncertainties of less than 5 km. The estimated plate geometry model exhibited large variation, including a pronounced convex structure that may be evidence of a subducted seamount in the eastern portion of study area, whereas the western part appeared smooth. We also found that the active earthquake region near the plate boundary, defined by the distance from our plate geometry model, was clearly separated from the area dominated by short-term slow-slip events (SSEs). The oceanic crust just beneath the SSE-dominant region, the western part of the study area, showed high Vp/Vs ratios (>1.8), whereas the eastern side showed moderate or low Vp/Vs (<1.75). We interpreted this as an indication that high fluid pressures near the surface of the slab are contributing to the SSE activities. Within the toe of the mantle wedge, P and S wave velocities (<7.5 and <4.2 km/s, respectively) lower than those observed through normal mantle peridotite might suggest that some portions of the mantle may be at least 40% serpentinized.

Design and simulation of the surface shape control system for membrane mirror

Science.gov (United States)

Zhang, Gengsheng; Tang, Minxue

2009-11-01

The surface shape control is one of the key technologies for the manufacture of membrane mirror. This paper presents a design of membrane mirror's surface shape control system on the basis of fuzzy logic control. The system contains such function modules as surface shape design, surface shape control, surface shape analysis, and etc. The system functions are realized by using hybrid programming technology of Visual C# and MATLAB. The finite element method is adopted to simulate the surface shape control of membrane mirror. The finite element analysis model is established through ANSYS Parametric Design Language (APDL). ANSYS software kernel is called by the system in background running mode when doing the simulation. The controller is designed by means of controlling the sag of the mirror's central crosssection. The surface shape of the membrane mirror and its optical aberration are obtained by applying Zernike polynomial fitting. The analysis of surface shape control and the simulation of disturbance response are performed for a membrane mirror with 300mm aperture and F/2.7. The result of the simulation shows that by using the designed control system, the RMS wavefront error of the mirror can reach to 142λ (λ=632.8nm), which is consistent to the surface accuracy of the membrane mirror obtained by the large deformation theory of membrane under the same condition.

Design methodology to enhance high impedance surfaces performances

Directory of Open Access Journals (Sweden)

M. Grelier

2014-04-01

Full Text Available A methodology is introduced for designing wideband, compact and ultra-thin high impedance surfaces (HIS. A parametric study is carried out to examine the effect of the periodicity on the electromagnetic properties of an HIS. This approach allows designers to reach the best trade-off for HIS performances.

Hydrological Design of Two Low-Impact Development Techniques in a Semi-Arid Climate Zone of Central Mexico

Directory of Open Access Journals (Sweden)

Liliana Lizárraga-Mendiola

2017-07-01

Full Text Available This paper deals with the design of a bioretention cell and an infiltration trench in a semi- arid micro watershed. The study area was analyzed by characteristics such as slope changes (S, direction and maximum length of the urban runoff (L, and soil use (runoff coefficient, Rc. The bioretention cell was designed by the calculation of variables such as drainage area (A, concentration time (Tc, rainfall intensity (i, maximum peak drained (Qmax, inlet and outlet runoff (Qa and Qout, respectively, temperature (T, evaporation (Ev, potential evapotranspiration (PEm, consumptive use (U for tolerant plants to semi-arid climates, and soil infiltration capacity (Inf. To design the infiltration trench, only Tc, Qmax, and i were taken into account. The results showed that the designed bioretention cell could retain between 5.37% and 2.25% of runoff volume. As the efficiency of the bioretention cell can be defined by the need for additional irrigation, our results showed that the cell is inefficient in some of the dry months (November and December, even in years characterized by abundant rainfall. Besides, it was shown that the designed infiltration trench could store or infiltrate the water from typical rain events. Based on these results, it is the implementation of more Low-Impact Development (LID for runoff management in the study area is recommended.

Technical considerations in the design of near surface disposal facilities for radioactive waste

International Nuclear Information System (INIS)

2001-11-01

Good design is an important step towards ensuring operational as well as long term safety of low and intermediate level waste (LILW) disposal. The IAEA has produced this report with the objective of outlining the most important technical considerations in the design of near surface disposal facilities and to provide some examples of the design process in different countries. This guidance has been developed in light of experience gained from the design of existing near surface disposal facilities in a range of Member States. In particular the report provide information on design objective, design requirements, and design phases. The report focuses on: near surface disposal facilities accepting solidified LILW; disposal facilities on or just below the ground surface, where the final protective covering is of the order of a few metres thick; and disposal facilities several tens of metres below the ground surface (including rock cavern type facilities)

Robust topology design of periodic grating surfaces

DEFF Research Database (Denmark)

Friis, Kasper Storgaard; Sigmund, Ole

2012-01-01

Modern nanoscale manufacturing techniques allow for a high degree of flexibility in designing surface microstructures and nanostructures. Injection molding of nanosized features allows for mass production of plastic components with a tailored nanostructure producing specific optical effects depen...

Geomembranes as an interim measure to control water infiltration at a low-level radioactive waste disposal area

International Nuclear Information System (INIS)

Weishan, M.R.; Sonntag, T.L.; Shehane, W.D.

1997-01-01

Using an exposed geomembrane an interim measure to cover a closed, Low-Level Radioactive Waste Disposal Area requires unique design and construction considerations. In response to a Resource Conservation and Recovery Act Administrative Consent Order, the New York State Energy Research and Development Authority (NYSERDA) used very low-density polyethylene (VLDPE) geomembrane as an interim measure to cover two soil-capped, grass-covered waste trenches to address a rapid increase in water accumulation in the trenches. Two years later, NYSERDA covered the remaining grass-covered trench caps with a reinforced ethylene interpolymer alloy (EIA-R) geomembrane to reduce water accumulation in these trenches. This paper addresses the differences in geomembrane materials and discusses the lessons learned during design, construction, and operation since installation of the covers. Discussed are the successes and obstacles regarding the use of both geomembrane materials as an exposed cover, selecting the geomembrane materials, anchoring the geomembrane from wind uplift, and mitigating the increased surface water runoff from the geomembrane covered area

The real business of web design

CERN Document Server

Waters, John

2004-01-01

Written by a veteran Web designer, The Real Business of Web Design goes beyond the usual philosophy of simply creating a better customer experience online. Instead, it provides an array of visual design practices and tested business principles for clarifying and simplifying the Web development process and making a Website more customer friendly. Filled with anecdotes from the author's own experiences in the web design trenches, this guide shows readers how to use the Web in crucial ways to streamline communications, speed up transactions, boost profits, and much more. Anyone who wants to use t

Design of a surface alloy catalyst for steam reforming

DEFF Research Database (Denmark)

Besenbacher, F.; Chorkendorff, Ib; Clausen, B.S.

1998-01-01

Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. insight into the structure of surface alloys combined with an understanding of the relation between the surface compositi...... and reactivity is shown to lead directly to new ideas for catalyst design, The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming....

Conditions of rib design for polycarbonate resin with high glossy surfaces

Energy Technology Data Exchange (ETDEWEB)

Jeong, Seong Won [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

2013-10-15

Much attention has been being given to the importance of product surfaces in the field of plastic parts, as industrial design has become one of the key elements of product success. These plastic parts incorporate rib-like geometries on the non-appearance surfaces of plastic in order to increase the stiffness of rigidity of the section, but they often cause appearance problems of the product's surface overall by making a sink mark on that surface. The thickness, height and draft-angle of the rib are generally known as major parameters influencing the sink mark on the appearance surface. Therefore, designers of plastic parts must determine the variables of reinforcing ribs. The goal of this study is to find the optimum design variables in the mixing conditions of the thickness, the height and the draft angle of reinforcing ribs so that designers of plastic parts can easily determine the conditions of the reinforcing ribs as the part's section thickness varies within an objective limit in polycarbonate plastic resin and a high glossy surface that are widely applied in the creation of plastic products. We investigated the actual depths of sink marks on the surface of a specimen that was manufactured with an injection mold specifically for this study. Response surface methodology with the Box-Behnken design was used to analyze the regression curve of real depths with combinations of the thickness, height and draft angle of the ribs. The result shows that the most influential factor to increase the shrinkage is the thickness of ribs and that the optimum value of the rib thickness is a range from multiple of 0.25 to 0.34 of the section thickness. Also, the rib height and rib draft angle are not major factors that can change the sink amount.

Conditions of rib design for polycarbonate resin with high glossy surfaces

International Nuclear Information System (INIS)

Jeong, Seong Won

2013-01-01

Much attention has been being given to the importance of product surfaces in the field of plastic parts, as industrial design has become one of the key elements of product success. These plastic parts incorporate rib-like geometries on the non-appearance surfaces of plastic in order to increase the stiffness of rigidity of the section, but they often cause appearance problems of the product's surface overall by making a sink mark on that surface. The thickness, height and draft-angle of the rib are generally known as major parameters influencing the sink mark on the appearance surface. Therefore, designers of plastic parts must determine the variables of reinforcing ribs. The goal of this study is to find the optimum design variables in the mixing conditions of the thickness, the height and the draft angle of reinforcing ribs so that designers of plastic parts can easily determine the conditions of the reinforcing ribs as the part's section thickness varies within an objective limit in polycarbonate plastic resin and a high glossy surface that are widely applied in the creation of plastic products. We investigated the actual depths of sink marks on the surface of a specimen that was manufactured with an injection mold specifically for this study. Response surface methodology with the Box-Behnken design was used to analyze the regression curve of real depths with combinations of the thickness, height and draft angle of the ribs. The result shows that the most influential factor to increase the shrinkage is the thickness of ribs and that the optimum value of the rib thickness is a range from multiple of 0.25 to 0.34 of the section thickness. Also, the rib height and rib draft angle are not major factors that can change the sink amount.

Design of structurally colored surfaces based on scalar diffraction theory

DEFF Research Database (Denmark)

Johansen, Villads Egede; Andkjær, Jacob Anders; Sigmund, Ole

2014-01-01

In this paper we investigate the possibility of controlling the color and appearance of surfaces simply by modifying the height profile of the surface on a nanoscale level. The applications for such methods are numerous: new design possibilities for high-end products, color engraving on any highly...... reflective surface, paint-free text and coloration, UV-resistant coloring, etc. In this initial study, the main focus is on finding a systematic way to obtain these results. For now the simulation and optimization is based on a simple scalar diffraction theory model. From the results, several design issues...

Case study: Free product recovery and site remediation using horizontal trenching, soil vapor treatment and groundwater extraction

International Nuclear Information System (INIS)

Sanderson, E.P.; Johnston, H.S. Jr.; Farrell, M.; Twedell, D.B.

1993-01-01

Sites with soil and groundwater impacted by petroleum hydrocarbons have been remediated using a variety of traditional techniques. However, when the site impacted lies within a very confined downtown area of an expanding metropolitan city, a more complex array of technologies must be considered. The Law Enforcement Center site is the City of Charlotte's worst known underground storage tank (UST) release to date. A cost effective free product recovery, soil vapor and groundwater extraction system is being piloted here using new horizontal trenching technology and state of the art equipment. On-site low permeability soil required that an alternative to standard recovery wells be developed for groundwater recovery and vapor extraction. Operation and maintenance (O and M) of the large number of recovery wells required would have been extremely costly over the expected lifetime of the project. Although horizontal trenching was the best solution to the O and M costs, many problems were encountered during their installation

The Impact of the Shallow-Trench Isolation Effect on Flicker Noise of Source Follower MOSFETs in a CMOS Image Sensor.

Science.gov (United States)

Fan, C C; Chiu, Y C; Liu, C; Lai, W W; Cheng, C H; Lin, D L; Li, G R; Lo, Y H; Chang, C W; Tsai, C C; Chang, C Y

2018-06-01

The flicker noise of source follower transistors is the dominant noise source in image sensors. This paper reports a systematic study of the shallow trench isolation effect in transistors with different sizes under high temperature conditions that correspond to the quantity of empty defect sites. The effects of shallow trench isolation sidewall defects on flicker noise characteristics are investigated. In addition, the low-frequency noise and subthreshold swing degrade simultaneously in accordance to the device gate width scaling. Both serious subthreshold leakage and considerable noise can be attributed to the high trap density near the STI edge. Consequently, we propose a coincidental relationship between the noise level and the subthreshold characteristic; its trend is identical to the experiments and simulation results.

Martian Surface as Seen by Phoenix

Science.gov (United States)

2008-01-01

This anaglyph, acquired by NASA's Phoenix Lander's Surface Stereo Imager on Sol 36, the 36th Martian day of the mission (July 1, 2008), shows a stereoscopic 3D view of a trench informally called 'Snow White' dug by Phoenix's Robotic Arm. Phoenix's solar panel is seen in the bottom right corner of the image. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Engineering design constraints of the lunar surface environment

Science.gov (United States)

Morrison, D. A.

1992-01-01

Living and working on the lunar surface will be difficult. Design of habitats, machines, tools, and operational scenarios in order to allow maximum flexibility in human activity will require paying attention to certain constraints imposed by conditions at the surface and the characteristics of lunar material. Primary design drivers for habitat, crew health and safety, and crew equipment are: ionizing radiation, the meteoroid flux, and the thermal environment. Secondary constraints for engineering derive from: the physical and chemical properties of lunar surface materials, rock distributions and regolith thicknesses, topography, electromagnetic properties, and seismicity. Protection from ionizing radiation is essential for crew health and safety. The total dose acquired by a crew member will be the sum of the dose acquired during EVA time (when shielding will be least) plus the dose acquired during time spent in the habitat (when shielding will be maximum). Minimizing the dose acquired in the habitat extends the time allowable for EVA's before a dose limit is reached. Habitat shielding is enabling, and higher precision in predicting secondary fluxes produced in shielding material would be desirable. Means for minimizing dose during a solar flare event while on extended EVA will be essential. Early warning of the onset of flare activity (at least a half-hour is feasible) will dictate the time available to take mitigating steps. Warning capability affects design of rovers (or rover tools) and site layout. Uncertainty in solar flare timing is a design constraint that points to the need for quickly accessible or constructible safe havens.

Environmental Acoustic Considerations for Passive Detection of Maritime Targets by Hydrophones in a Deep Ocean Trench

Science.gov (United States)

2010-06-01

Science and Technology. Available: http://cmst.curtin.edu.au/local/docs/ products / actup_v2_2l_installation_user_guide.pdf (accessed 2 June 2010...noisecurve112(:,6)); %% Intergrating Noise Level Trench A n2=0; Itot=0; phi_t=atan(D1/L1); m=1; while (phi(m,1)>phi_t) m=m+1; end

Optimum Sea Surface Displacement and Fault Slip Distribution of the 2017 Tehuantepec Earthquake (Mw 8.2) in Mexico Estimated From Tsunami Waveforms

Science.gov (United States)

Gusman, Aditya Riadi; Mulia, Iyan E.; Satake, Kenji

2018-01-01

The 2017 Tehuantepec earthquake (Mw 8.2) was the first great normal fault event ever instrumentally recorded to occur in the Middle America Trench. The earthquake generated a tsunami with an amplitude of 1.8 m (height = 3.5 m) in Puerto Chiapas, Mexico. Tsunami waveforms recorded at coastal tide gauges and offshore buoy stations were used to estimate the optimum sea surface displacement without assuming any fault. Our optimum sea surface displacement model indicated that the maximum uplift of 0.5 m is located near the trench and the maximum subsidence of 0.8 m on the coastal side near the epicenter. We then estimated the fault slip distribution that can best explain the optimum sea surface displacement assuming 10 different fault geometries. The best model suggests that a compact region of large slip (3-6 m) extends from a depth of 30 km to 90 km, centered at a depth of 60 km.

Selection of a design for response surface

Science.gov (United States)

Ranade, Shruti Sunil; Thiagarajan, Padma

2017-11-01

Box-Behnken, Central-Composite, D and I-optimal designs were compared using statistical tools. Experimental trials for all designs were generated. Random uniform responses were simulated for all models. R-square, Akaike and Bayesian Information Criterion for the fitted models were noted. One-way ANOVA and Tukey’s multiple comparison test were performed on these parameters. These models were evaluated based on the number of experimental trials generated in addition to the results of the statistical analyses. D-optimal design generated 12 trials in its model, which was lesser in comparison to both Central Composite and Box-Behnken designs. The R-square values of the fitted models were found to possess a statistically significant difference (P<0.0001). D-optimal design not only had the highest mean R-square value (0.7231), but also possessed the lowest means for both Akaike and Bayesian Information Criterion. The D-optimal design was recommended for generation of response surfaces, based on the assessment of the above parameters.

The Phoenix Mars Lander Robotic Arm

Science.gov (United States)

Bonitz, Robert; Shiraishi, Lori; Robinson, Matthew; Carsten, Joseph; Volpe, Richard; Trebi-Ollennu, Ashitey; Arvidson, Raymond E.; Chu, P. C.; Wilson, J. J.; Davis, K. R.

2009-01-01

The Phoenix Mars Lander Robotic Arm (RA) has operated for over 150 sols since the Lander touched down on the north polar region of Mars on May 25, 2008. During its mission it has dug numerous trenches in the Martian regolith, acquired samples of Martian dry and icy soil, and delivered them to the Thermal Evolved Gas Analyzer (TEGA) and the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA). The RA inserted the Thermal and Electrical Conductivity Probe (TECP) into the Martian regolith and positioned it at various heights above the surface for relative humidity measurements. The RA was used to point the Robotic Arm Camera to take images of the surface, trenches, samples within the scoop, and other objects of scientific interest within its workspace. Data from the RA sensors during trenching, scraping, and trench cave-in experiments have been used to infer mechanical properties of the Martian soil. This paper describes the design and operations of the RA as a critical component of the Phoenix Mars Lander necessary to achieve the scientific goals of the mission.

Soil Characteristics and Lodgepole Pine (Pinus contorta var. latifolia Performance Two Decades after Disk Trenching of Unburned and Broadcast-Burned Plots in Subboreal British Columbia

Directory of Open Access Journals (Sweden)

Jacob O. Boateng

2011-01-01

Full Text Available We examined the effects of low-impact broadcast-burning and disk-trenching planting position (control, hinge, trench on soil characteristics and lodgepole pine foliar nutrition and growth over two decades at a subboreal site in British Columbia, Canada. Broadcast burning had virtually no effect on either the bulk density or chemical properties of soil. In contrast, significant reductions in soil bulk density and increases in soil nutrient availability persisted for 20 years in hinge position soils relative to undisturbed (control soil between trenches. These effects on bulk density and nutrient availability are associated with significant differences in pine size by year 6. Burning and planting positions interacted significantly in their effect on pine height, diameter, and stem volume for at least 19 years. Pine survival was high regardless of burning or planting position. Neither broadcast burning nor planting position significantly affected lodgepole pine foliar nutrient status in this study.

Conceptual design report for Central Waste Disposal Facility

International Nuclear Information System (INIS)

1984-01-01

The permanent facilities are defined, and cost estimates are provided for the disposal of Low-Level Radioactive Wastes (LLW) at the Central Waste Disposal Facility (CWDF). The waste designated for the Central Waste Disposal Facility will be generated by the Y-12 Plant, the Oak Ridge Gaseous Diffusion Plant, and the Oak Ridge National Laboratory. The facility will be operated by ORNL for the Office of Defense Waste and By-Products Management of the Deparment of Energy. The CWDF will be located on the Department of Energy's Oak Ridge Reservation, west of Highway 95 and south of Bear Creek Road. The body of this Conceptual Design Report (CDR) describes the permanent facilities required for the operation of the CWDF. Initial facilities, trenches, and minimal operating equipment will be provided in earlier projects. The disposal of LLW will be by shallow land burial in engineered trenches. DOE Order 5820 was used as the performance standard for the proper disposal of radioactive waste. The permanent facilities are intended for beneficial occupancy during the first quarter of fiscal year 1989. 3 references, 9 figures, 7 tables

Microdose Induced Drain Leakage Effects in Power Trench MOSFETs: Experiment and Modeling

Science.gov (United States)

Zebrev, Gennady I.; Vatuev, Alexander S.; Useinov, Rustem G.; Emeliyanov, Vladimir V.; Anashin, Vasily S.; Gorbunov, Maxim S.; Turin, Valentin O.; Yesenkov, Kirill A.

2014-08-01

We study experimentally and theoretically the micro-dose induced drain-source leakage current in the trench power MOSFETs under irradiation with high-LET heavy ions. We found experimentally that cumulative increase of leakage current occurs by means of stochastic spikes corresponding to a strike of single heavy ion into the MOSFET gate oxide. We simulate this effect with the proposed analytic model allowing to describe (including Monte Carlo methods) both the deterministic (cumulative dose) and stochastic (single event) aspects of the problem. Based on this model the survival probability assessment in space heavy ion environment with high LETs was proposed.

Effect of design factors on surface temperature and wear in disk brakes

Science.gov (United States)

Santini, J. J.; Kennedy, F. E.; Ling, F. F.

1976-01-01

The temperatures, friction, wear and contact conditions that occur in high energy disk brakes are studied. Surface and near surface temperatures were monitored at various locations in a caliper disk brake during drag type testing, with friction coefficient and wear rates also being determined. The recorded transient temperature distributions in the friction pads and infrared photographs of the rotor disk surface both showed that contact at the friction surface was not uniform, with contact areas constantly shifting due to nonuniform thermal expansion and wear. The effect of external cooling and of design modifications on friction, wear and temperatures was also investigated. It was found that significant decreases in surface temperature and in wear rate can be achieved without a reduction in friction either by slotting the contacting face of the brake pad or by modifying the design of the pad support to improve pad compliance. Both design changes result in more uniform contact conditions on the friction surface.

Geological Mapping of Investigation Trenches OL-TK15 and OL-TK16 at the Olkiluoto Study Site, Eurajoki, SW Finland

International Nuclear Information System (INIS)

Vaarma, M.; Vuokko, J.

2009-07-01

Geological mapping of investigation trenches OL-TK15 and OL-TK16 was carried out by the Geological Survey of Finland (GTK) at the Olkiluoto study site as a part of Posiva Oy's site investigation program for the development of an underground repository for nuclear waste. OL-TK15 is ca. N-S striking and ca. 95 m long, and OL-TK16 is ca. E-W striking and ca. 172 m long. The trenches were cleaned with pressure washer and pressurized air. The rock types were determined in field by naked eyes. Five samples from OL-TK15 and 10 samples from OL-TK16 were thin sectioned and investigated microscopically. In addition, petrophysical measurements were carried out by GTK geophysical laboratory for these samples. The bedrock within the excavation trenches OL-TK15 and OL-TK16 consists mainly of veined gneiss (VGN) with intercalations of mica gneiss (MGN), and mafic gneiss (MFGN) of amphibolite, amphibolite-gneiss, and skarn gneiss. The VGN is frankly solid or intact, fine grained and weakly banded and multiple intruded by granitic and pegmatitic veins and veinlets. Narrow scrappy zones occupied by dark dots of highly altered pseudomorphs after cordierite and/or garnet tend to be common in places. In addition, VGN contains rounded oblong mafic to intermediate fragments due to boudination of competent layers and/or dykes. Some rather narrow pegmatitic and quartz veins cut the previous tectonic structures. The prevailing tectonic structures are strong pervasive foliation and conformal veining of several generations mostly granitic in composition. The strike of the foliation and banding and veining as well, varies a little from NNE to ENE and the dip is ca. 40 - 50 degrees to SE sector, respectively. The younger folding has bent the older foliation and neosomic veining mostly with dextral monoclinic style so that in many places there occur tight kinky nodes and rootles augen like knots showing dextral rotation, too. Due to brittle deformation, there are some shear zones and zones with

Light-absorbent liquid immersion angled exposure for patterning 3D samples with vertical sidewalls

International Nuclear Information System (INIS)

Kumagai, Shinya; Kubo, Hironori; Sasaki, Minoru

2017-01-01

To make photolithography patterns on 3D samples, the angled (inclined) exposure technique has been used so far. However, technological issues have emerged in making photolithography patterns on the surface of trench structures. The surface of the trench structures can be covered with a photoresist film by spray-coating but the photoresist film deposited on the sidewalls and bottom of the trench is generally thin. The thin photoresist film deposited inside the trench has been easily overdosed. Moreover, irregular patterns have frequently been formed by the light reflected inside the trench. In this study, we have developed liquid immersion photolithography using a light-absorbent material. The light-reflection inside the trench was suppressed. Various patterns were transferred in the photoresist film deposited on the trench structures which had an aspect ratio of 0.74. Compared to immersion photolithography using pure water under p -polarization light control, the light-absorbent liquid immersion photolithography developed here patterned well the surfaces of the trench sidewalls and bottom. (paper)

Chemical mechanisms of 60Co transport in ground water from intermediate-level liquid waste trench 7: progress report for period ending June 30, 1975

International Nuclear Information System (INIS)

Means, J.L.; Crerar, D.A.; Duguid, J.O.

1976-11-01

A seep approximately 50 meters east of trench 7 within the ORNL restricted area contains 60 Co in concentrations of 10 4 to 10 6 dpm/g in the soil and 10 3 dpm/ml in the water. Traces of 125 Sb and various transuranics have also been detected in the soil. However, because the volume of water discharge from the seep is small, the total radionuclide contribution from the trench 7 area to White Oak Creek and the Clinch River is insignificant. The 60 Co is transported in the ground-water from the trench to the seep as organic complexes and is absorbed by manganese oxides and to a lesser extent by iron sesquioxides in the shale and soil. In the absence of these organic complexing agents, 60 Co mobilization would be negligible because the sediment absorption capacity for inorganic forms of 60 Co is extremely high. The primary objective of this study has been to investigate 60 Co transport and absorption mechanisms as observed in the study area. Because the organic complexing characteristics of transition metals and transuranics are similar, the mechanisms of 60 Co transport determined in this study may also apply to plutonium and other alpha-emitters. Also the experimental and analytical methods employed in this study apply to the identification of other migrating radionuclide complexes from other disposal trenches and pits at ORNL. The increased knowledge of transport and adsorption mechanisms will provide insight into methods of controlling the movement of radionuclides from these and future disposal areas

Reliability-based design optimization via high order response surface method

International Nuclear Information System (INIS)

Li, Hong Shuang

2013-01-01

To reduce the computational effort of reliability-based design optimization (RBDO), the response surface method (RSM) has been widely used to evaluate reliability constraints. We propose an efficient methodology for solving RBDO problems based on an improved high order response surface method (HORSM) that takes advantage of an efficient sampling method, Hermite polynomials and uncertainty contribution concept to construct a high order response surface function with cross terms for reliability analysis. The sampling method generates supporting points from Gauss-Hermite quadrature points, which can be used to approximate response surface function without cross terms, to identify the highest order of each random variable and to determine the significant variables connected with point estimate method. The cross terms between two significant random variables are added to the response surface function to improve the approximation accuracy. Integrating the nested strategy, the improved HORSM is explored in solving RBDO problems. Additionally, a sampling based reliability sensitivity analysis method is employed to reduce the computational effort further when design variables are distributional parameters of input random variables. The proposed methodology is applied on two test problems to validate its accuracy and efficiency. The proposed methodology is more efficient than first order reliability method based RBDO and Monte Carlo simulation based RBDO, and enables the use of RBDO as a practical design tool.

Surface mechanics design by cavitation peening

OpenAIRE

Hitoshi Soyama

2015-01-01

Although impacts at cavitation bubble collapses cause severe damage in hydraulic machineries, the cavitation impacts can be utilised for surface mechanics design such as introduction of compressive residual stress and/or improvement of fatigue strength. The peening method using the cavitation impacts was called as cavitation peening. In order to reveal the peening intensity of hydrodynamic cavitation and laser cavitation, the arc height of Almen strip and duralumin plate were measured. In the...

Identifying Preserved Storm Events on Beaches from Trenches and Cores

Science.gov (United States)

Wadman, H. M.; Gallagher, E. L.; McNinch, J.; Reniers, A.; Koktas, M.

2014-12-01

Recent research suggests that even small scale variations in grain size in the shallow stratigraphy of sandy beaches can significantly influence large-scale morphology change. However, few quantitative studies of variations in shallow stratigraphic layers, as differentiated by variations in mean grain size, have been conducted, in no small part due to the difficulty of collecting undisturbed sediment cores in the energetic lower beach and swash zone. Due to this lack of quantitative stratigraphic grain size data, most coastal morphology models assume that uniform grain sizes dominate sandy beaches, allowing for little to no temporal or spatial variations in grain size heterogeneity. In a first-order attempt to quantify small-scale, temporal and spatial variations in beach stratigraphy, thirty-five vibracores were collected at the USACE Field Research Facility (FRF), Duck, NC, in March-April of 2014 using the FRF's Coastal Research and Amphibious Buggy (CRAB). Vibracores were collected at set locations along a cross-shore profile from the toe of the dune to a water depth of ~1m in the surf zone. Vibracores were repeatedly collected from the same locations throughout a tidal cycle, as well as pre- and post a nor'easter event. In addition, two ~1.5m deep trenches were dug in the cross-shore and along-shore directions (each ~14m in length) after coring was completed to allow better interpretation of the stratigraphic sequences observed in the vibracores. The elevations of coherent stratigraphic layers, as revealed in vibracore-based fence diagrams and trench data, are used to relate specific observed stratigraphic sequences to individual storm events observed at the FRF. These data provide a first-order, quantitative examination of the small-scale temporal and spatial variability of shallow grain size along an open, sandy coastline. The data will be used to refine morphological model predictions to include variations in grain size and associated shallow stratigraphy.

Solid Waste Operations Complex W-113, Detail Design Report (Title II). Volume 1: Title II design report

International Nuclear Information System (INIS)

1995-09-01

The Solid Waste Retrieval Facility--Phase 1 (Project W113) will provide the infrastructure and the facility required to retrieve from Trench 04, Burial ground 4C, contact handled (CH) drums and boxes at a rate that supports all retrieved TRU waste batching, treatment, storage, and disposal plans. This includes (1) operations related equipment and facilities, viz., a weather enclosure for the trench, retrieval equipment, weighing, venting, obtaining gas samples, overpacking, NDE, NDA, shipment of waste and (2) operations support related facilities, viz., a general office building, a retrieval staff change facility, and infrastructure upgrades such as supply and routing of water, sewer, electrical power, fire protection, roads, and telecommunication. Title I design for the operations related equipment and facilities was performed by Raytheon/BNFL, and that for the operations support related facilities including infrastructure upgrade was performed by KEH. These two scopes were combined into an integrated W113 Title II scope that was performed by Raytheon/BNFL. Volume 1 provides a comprehensive narrative description of the proposed facility and systems, the basis for each of the systems design, and the engineering assessments that were performed to support the technical basis of the Title II design. The intent of the system description presented is to provide WHC an understanding of the facilities and equipment provided and the A/E's perspective on how these systems will operate

Finite Element Analysis of IPS Empress II Ceramic Bridge Reinforced by Zirconia Bar.

Science.gov (United States)

Kermanshah, H; Bitaraf, T; Geramy, A

2012-01-01

The aim of this study was to determine the effect of trenched zirconia bar on the von Mises stress distribution of IPS -Empress II core ceramics. The three-dimensional model including a three-unit bridge from the second premolar to the second molar was designed. The model was reinforced with zirconia bar (ZB), zirconia bar with vertical trench (VZB) and zirconia bar with horizontal trench (HZB) (cross sections of these bars were circular). The model without zirconia bar was designed as the control. The bridges were loaded by 200 N and 500 N on the occlusal surface at the middle of the pontic component and von Mises stresses were evaluated along a defined path. IN THE CONNECTOR AREA, VON MISES STRESS IN MPA WERE APPROXIMATELY IDENTICAL IN THE SPECIMENS WITH ZB (AT MOLAR CONNECTOR (MC): 4.75 and at premolar connector (PC): 6.40) and without ZB (MC: 5.50, PC: 6.68), and considerable differences were not recognized. Whereas, Von-Mises stress (MPa) in the specimens with horizontal trenched Zirconia bar (HZB) (MC: 3.91, PC: 2.44) and Vertical trenched Zirconia bar (VZB) (MC: 2.53, PC: 2.56) was decreased considerably. Embeded trenched zirconia bar could reinforce IPS-Empress II at the connector area which is a main failure region in all ceramic fixed partial dentures.

Finite Element Analysis of IPS –Empress II Ceramic Bridge Reinforced by Zirconia Bar

Directory of Open Access Journals (Sweden)

Allahyar Geramy

2012-01-01

Full Text Available Objective: The aim of this study was to determine the effect of trenched zirconia bar on the von Mises stress distribution of IPS –Empress II core ceramics.Material and Methods: The three-dimensional model including a three-unit bridge from the second premolar to the second molar was designed. The model was reinforced with zirconia bar (ZB, zirconia bar with vertical trench (VZB, and zirconia bar with horizontal trench (HZB (cross sections of these bars were circular. The model without zirconia bar was designed as the control. The bridges were loaded by 200 N and 500 N on the occlusal surface at the middle of the pontic component, and Von-Mises stresses were evaluated along a defined path.Result: In the connector area, VonMises stress in MPa were approximately identical in the specimens with ZB (at molar connector (MC: 4.75, and at premolar connector (PC: 6.40 and without ZB (MC: 5.50, PC: 6.68, and considerable differences were not recognized. Whereas, Von-Mises stress (MPa in the specimens with horizontal trenched Zirconia bar (HZB (MC: 3.91, PC: 2.44 and Vertical trenched Zirconia bar (VZB (MC: 2.53, PC: 2.56 was decreased considerably.Conclusion: Embeded trenched zirconia bar could reinforce IPS-Empress II at the connector area which is a main failure region in all ceramic fixed partial dentures.

Groundwater monitoring plan for the 300 Area process trenches

Energy Technology Data Exchange (ETDEWEB)

Lindberg, J.W.; Chou, C.J.; Johnson, V.G.

1995-05-23

This document describes the groundwater monitoring program for the Hanford Site 300 Area Process Trenches (300 APT). The 300 APT are a Resource Conservation and Recovery Act of 1976 (RCRA) regulated unit. The 300 APT are included in the Dangerous Waste Portion of the Resource Conservation and Recovery Act Permit for the Treatment, Storage, and Disposal of Dangerous Waste, Permit No. WA890008967, and are subject to final-status requirements for groundwater monitoring. This document describes a compliance monitoring program for groundwater in the uppermost aquifer system at the 300 APT. This plan describes the 300 APT monitoring network, constituent list, sampling schedule, statistical methods, and sampling and analysis protocols that will be employed for the 300 APT. This plan will be used to meet groundwater monitoring requirements from the time the 300 APT becomes part of the Permit and through the postclosure care period until certification of final closure.

Computational design of protein interactions: designing proteins that neutralize influenza by inhibiting its hemagglutinin surface protein

Science.gov (United States)

Fleishman, Sarel

2012-02-01

Molecular recognition underlies all life processes. Design of interactions not seen in nature is a test of our understanding of molecular recognition and could unlock the vast potential of subtle control over molecular interaction networks, allowing the design of novel diagnostics and therapeutics for basic and applied research. We developed the first general method for designing protein interactions. The method starts by computing a region of high affinity interactions between dismembered amino acid residues and the target surface and then identifying proteins that can harbor these residues. Designs are tested experimentally for binding the target surface and successful ones are affinity matured using yeast cell surface display. Applied to the conserved stem region of influenza hemagglutinin we designed two unrelated proteins that, following affinity maturation, bound hemagglutinin at subnanomolar dissociation constants. Co-crystal structures of hemagglutinin bound to the two designed binders were within 1Angstrom RMSd of their models, validating the accuracy of the design strategy. One of the designed proteins inhibits the conformational changes that underlie hemagglutinin's cell-invasion functions and blocks virus infectivity in cell culture, suggesting that such proteins may in future serve as diagnostics and antivirals against a wide range of pathogenic influenza strains. We have used this method to obtain experimentally validated binders of several other target proteins, demonstrating the generality of the approach. We discuss the combination of modeling and high-throughput characterization of design variants which has been key to the success of this approach, as well as how we have used the data obtained in this project to enhance our understanding of molecular recognition. References: Science 332:816 JMB, in press Protein Sci 20:753

Development of a high energy pulsed plasma simulator for the study of liquid lithium trenches

Energy Technology Data Exchange (ETDEWEB)

Jung, S., E-mail: jung73@illinois.edu [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Christenson, M.; Curreli, D. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Bryniarski, C. [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States); Andruczyk, D.; Ruzic, D.N. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 (United States)

2014-12-15

Highlights: • A pulse device for a liquid lithium trench study is developed. • It consists of a coaxial plasma gun, a theta pinch, and guiding magnets. • A large energy enhancement is observed with the use of the plasma gun. • A further increase in energy and velocity is observed with the theta pinch. - Abstract: To simulate detrimental events in a tokamak and provide a test-stand for a liquid-lithium infused trench (LiMIT) device [1], a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. The plasma is characterized using a triple Langmuir probe, optical methods, and a calorimeter. Clear advantages have been observed with the application of a coaxial plasma accelerator as a pre-ionization source. The experimental results of the plasma gun in conjunction with the existing theta pinch show a significant improvement from the previous energy deposition by a factor of 14 or higher, resulting in a maximum energy and heat flux of 0.065 ± 0.002 MJ/m{sup 2} and 0.43 ± 0.01 GW/m{sup 2}. A few ways to further increase the plasma heat flux for LiMIT experiments are discussed.

Development of a high energy pulsed plasma simulator for the study of liquid lithium trenches

International Nuclear Information System (INIS)

Jung, S.; Christenson, M.; Curreli, D.; Bryniarski, C.; Andruczyk, D.; Ruzic, D.N.

2014-01-01

Highlights: • A pulse device for a liquid lithium trench study is developed. • It consists of a coaxial plasma gun, a theta pinch, and guiding magnets. • A large energy enhancement is observed with the use of the plasma gun. • A further increase in energy and velocity is observed with the theta pinch. - Abstract: To simulate detrimental events in a tokamak and provide a test-stand for a liquid-lithium infused trench (LiMIT) device [1], a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. The plasma is characterized using a triple Langmuir probe, optical methods, and a calorimeter. Clear advantages have been observed with the application of a coaxial plasma accelerator as a pre-ionization source. The experimental results of the plasma gun in conjunction with the existing theta pinch show a significant improvement from the previous energy deposition by a factor of 14 or higher, resulting in a maximum energy and heat flux of 0.065 ± 0.002 MJ/m 2 and 0.43 ± 0.01 GW/m 2 . A few ways to further increase the plasma heat flux for LiMIT experiments are discussed

Annual Report RCRA Post-Closure Monitoring and Inspections for CAU 112: Area 23 Hazardous Waste Trenches, Nevada Test Site, Nevada, for the period October 2000-July 2001

International Nuclear Information System (INIS)

Tobiason, D. S.

2002-01-01

This annual Neutron Soil Moisture Monitoring report provides an analysis and summary for site inspections, meteorological information, and neutron soil moisture monitoring data obtained at the Area 23 Hazardous Waste Trenches Resource Conservation and Recovery Act (RCRA) unit, located in Area 23 of the Nevada Test Site, Nye County, Nevada, during the October 2000--July 2001 monitoring period. Inspections of the Area 23 Hazardous Waste Trenches RCRA unit are conducted to determine and document the physical condition of the covers, facilities, and any unusual conditions that could impact the proper operation of the waste unit closure. Physical inspections of the closure were completed quarterly and indicated that the site is in good condition with no significant findings noted. An annual subsidence survey of the elevation markers was conducted in July 2001. There has been no subsidence at any of the markers since monitoring began eight years ago. Precipitation for the period October 2000 through July 2001 was 9.42 centimeters (cm) (3.71 inches [in]) (U.S. National Weather Service, 2001). The prior year annual rainfall (January 2000 through December 2000) was 10.44 cm (4.1 1 in.). The recorded average annual rainfall for this site from 1972 to January 2000 is 14.91 cm (5.87 in.). The objective of the neutron logging program is to monitor the soil moisture conditions along 30 neutron access tubes and detect changes that may be indicative of moisture movement at a point located directly beneath each trench. All monitored access tubes are within the compliance criteria of less than 5 percent residual volumetric moisture content at the compliance point directly beneath each respective trench. Soil conditions remain dry and stable underneath the trenches

Integrating Surface Modeling into the Engineering Design Graphics Curriculum

Science.gov (United States)

Hartman, Nathan W.

2006-01-01

It has been suggested there is a knowledge base that surrounds the use of 3D modeling within the engineering design process and correspondingly within engineering design graphics education. While solid modeling receives a great deal of attention and discussion relative to curriculum efforts, and rightly so, surface modeling is an equally viable 3D…

The distribution of radionuclides and some trace metals in the water columns of the Japan and Bonin trenches; Repartition des nucleides radioactifs et de quelques metaux-traces dans les fosses du Japon et des iles Bonin

Energy Technology Data Exchange (ETDEWEB)

Nozari, Y.; Yamada, M. [Tokyo Univ. (Japan). Ocean Research Inst; Nakanishi, T. [Kanazawa Univ. (Japan). Dept. of Chemistry; Nagaya, Y.; Nakamura, K.; Yamada, M. [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan); Shitashima, K.; Tsubota, H. [Hiroshima Univ. (Japan). Faculty of Integrated Arts and Sciences

1998-05-01

Presented here is the first geochemical data on the U/Th series Th, Pa, Ac, and Pb isotopes and artificial fallout radionuclides ({sup 90}Sr, {sup 137}Cs, and Pu isotopes), and some trace elements (V, Zn, Cd, Cu, Mn, and Ni) in two water columns of the Japan and Bonin trenches down to the bottom depths of 7585 m and 9750 m, respectively. Hydrographic properties such as temperature, salinity dissolved oxygen, and nutrient content within the trench valley remain constant at the same levels as those in the bottom water of the Northwest Pacific basin (typically {approx}6000 m in depth). The radionuclide activities and most trace metal concentrations are also not very different from those in the overlying water at depths of around 5000-6000 m. This means that any chemical alteration which sea water undergoes during its residence within the trench was not obviously detected by the techniques used here. The suggestion follows that the trench water is rather freely communicating y isopycnal mixing with the bottom water overlying the Northwest Pacific abyssal plain. The trench waters contain high {sup 239,240}Pu activities throughout, indicating that Pu is actively regenerating from rapidly sinking, large particles at the bottom interface, probably due to a change in the oxidation state. On the other hand, the vertical profiles of {sup 210}Pb and {sup 231}Pa show lower activities within the trench than those in the overlying deep waters, suggesting that the effect of boundary and bottom scavenging is significant in controlling their oceanic distributions. However, none of the trace metals studied here obviously follows the behaviour of the above nuclides. The {sup 228}Th data show scattering within the Bonin Trench that is largely ascribable to analytical errors. If, however we accept that the scatter of {sup 228}Th data is real and the variation is caused solely by decay of its parent {sup 228}Ra, we can set an upper limit of {approx}5 years for the renewal time of the

Design and construction of an interceptor system for radioactively contaminated solvent

International Nuclear Information System (INIS)

Weiss, T.G. Jr.; Blickwedehl, R.R.

1991-01-01

During the conduct of fuel reprocessing operations at the Western New York Nuclear Service Center from 1966 to 1972, the site operator disposed of spent solvent by shallow land burial in the area used for disposal of solid radioactive waste. The spent solvent was placed in twenty-two 3785 liter (1000-gallon) steel tanks which were then placed in eight 6-meter-deep burial holes. With the passage of time groundwater entered the tanks displacing the solvent (a mixture of tributyl phosphate and n-dodecane) and allowing it to enter the surrounding groundwater system. The solvent, which is lighter than water, floated to the surface of the groundwater within the burial holes and began to migrate laterally through cracks caused by weathering. In 1983, after the US Department of Energy (DOE) initiated efforts for the West Valley Demonstration Project (WVDP), trace amounts of solvent were encountered in a monitoring well near the perimeter of the burial area. Since the initial discovery, extensive studies and continued monitoring have been conducted of the solvent migration. In the fall of 1989, this monitoring showed evidence of further on-site migration of the solvent within the disposal area. In response, the DOE authorized West Valley Nuclear Services Company, Inc. (WVNS) to proceed with the design and construction of a trench system to intercept the flow of solvent and prevent it from discharging to nearby streams. Since the solvent and the contaminated groundwater samples taken in the area exhibited high levels of Iodine-129 in an organic complex, it was necessary to construct a pretreatment facility. An important aspect of the trench construction was the management of contaminated soil and construction water. Contaminated soils were placed into storage containers and held for future treatment and disposal. All water pumped from the trench during construction was stored in large bladder tanks, analyzed for hazardous constituents, and upon finding none, was discharged

Gas-surface dynamics and charging effects during plasma processing of semiconductors

Science.gov (United States)

Hwang, Gyeong Soon

This thesis work attempts to elucidate the fundamentals of gas-surface interactions that occur during plasma etching. Controlled experiments using hyperthermal fluorine beams have enabled us to uncover the scattering dynamics at complex surfaces similar to those encountered in etching. By analyzing energy and angular distributions of inelastically scattered F atoms, we were able to distinguish single- and multiple-bounce scattering and to develop models to describe these exit channels. Furthermore, we found that hard-sphere collision kinematics can capture well the energy transfer of the hyperthermal F atoms onto fluorinated silicon surfaces. Based on the fundamental scattering information, we have developed a kinetic model that is described by two parameters: (1) direct inelastic scattering probability and (2) sticking (reaction) probability. These parameters are formulated as a function of the incident energy and angle of F atoms. By incorporating the empirical kinetic model into Monte Carlo based profile evolution simulations, we have unraveled the origin of many etch profile peculiarities which appear during hyperthermal F-beam etching, such as microtrenching, inverse microloading, and undercutting. The kinetic model has been used to describe successfully etching in Cl2-plasmas. For the study of pattern-dependent charging, we have developed a numerical model that combines plasma, sheath, and charging dynamics. The charging simulations illustrate that the directionality difference between ions and electrons arriving at the wafer, brought about by the sheath, causes differential charging on patterned areas even when the plasma is uniform. Using the newly developed charging model, we have investigated gate oxide damage. The results show that a potential drop across the thin gate oxide caused by differential microstructure charging is primarily responsible for gate oxide degradation by driving Fowler-Nordheim stress currents. In general, increasing the flux of low

Novel freeform optical surface design with spiral symmetry

Science.gov (United States)

Zamora, Pablo; Benítez, Pablo; Miñano, Juan C.; Vilaplana, Juan

2011-10-01

Manufacturing technologies as injection molding or embossing specify their production limits for minimum radii of the vertices or draft angle for demolding, for instance. These restrictions may limit the system optical efficiency or affect the generation of undesired artifacts on the illumination pattern when dealing with optical design. A novel manufacturing concept is presented here, in which the optical surfaces are not obtained from the usual revolution symmetry with respect to a central axis (z axis), but they are calculated as free-form surfaces describing a spiral trajectory around z axis. The main advantage of this new concept lies in the manufacturing process: a molded piece can be easily separated from its mold just by applying a combination of rotational movement around axis z and linear movement along axis z, even for negative draft angles. The general designing procedure will be described in detail.

Experimental study of lithium free-surface flow for IFMIF target design

International Nuclear Information System (INIS)

Kondo, H.; Fujisato, A.; Yamaoka, N.; Inoue, S.; Miyamoto, S.; Iida, T.; Nakamura, H.; Ida, M.; Matushita, I.; Muroga, T.; Horiike, H.

2006-01-01

Lithium free-surface flow experiments to verify the design of IFMIF target have been carried out at Osaka University. The present report summarizes experimental results of surface phenomena, and cavitation characteristics of the loop, so as to try to apply these results to design parameters. Waves on the lithium flow surface is similar to that on water, and can be predicted by a linear stability theory. The wave amplitude is measured by an electro-contact probe. Surface roughness on a target nozzle, caused for example by attached chemical compounds and/or wastages by erosion and corrosion, can lead to a significant loss of target flow stability as well as surface wakes. The need of a polishing manipulator or exchange of the nozzle may be anticipated. Cavitation characteristic of the loop was measured by an accelerometer. From the results, a friction factor could be estimated fort he lithium flow

Chemical mechanisms of /sup 60/Co transport in ground water from intermediate-level liquid waste trench 7: progress report for period ending June 30, 1975

Energy Technology Data Exchange (ETDEWEB)

Means, J.L.; Crerar, D.A.; Duguid, J.O.

1976-11-01

A seep approximately 50 meters east of trench 7 within the ORNL restricted area contains /sup 60/Co in concentrations of 10/sup 4/ to 10/sup 6/ dpm/g in the soil and 10/sup 3/ dpm/ml in the water. Traces of /sup 125/Sb and various transuranics have also been detected in the soil. However, because the volume of water discharge from the seep is small, the total radionuclide contribution from the trench 7 area to White Oak Creek and the Clinch River is insignificant. The /sup 60/Co is transported in the ground-water from the trench to the seep as organic complexes and is absorbed by manganese oxides and to a lesser extent by iron sesquioxides in the shale and soil. In the absence of these organic complexing agents, /sup 60/Co mobilization would be negligible because the sediment absorption capacity for inorganic forms of /sup 60/Co is extremely high. The primary objective of this study has been to investigate /sup 60/Co transport and absorption mechanisms as observed in the study area. Because the organic complexing characteristics of transition metals and transuranics are similar, the mechanisms of /sup 60/Co transport determined in this study may also apply to plutonium and other alpha-emitters. Also the experimental and analytical methods employed in this study apply to the identification of other migrating radionuclide complexes from other disposal trenches and pits at ORNL. The increased knowledge of transport and adsorption mechanisms will provide insight into methods of controlling the movement of radionuclides from these and future disposal areas.

A synthetic seismicity model for the Middle America Trench

Science.gov (United States)

Ward, Steven N.

1991-01-01

A novel iterative technique, based on the concept of fault segmentation and computed using 2D static dislocation theory, for building models of seismicity and fault interaction which are physically acceptable and geometrically and kinematically correct, is presented. The technique is applied in two steps to seismicity observed at the Middle America Trench. The first constructs generic models which randomly draw segment strengths and lengths from a 2D probability distribution. The second constructs predictive models in which segment lengths and strengths are adjusted to mimic the actual geography and timing of large historical earthquakes. Both types of models reproduce the statistics of seismicity over five units of magnitude and duplicate other aspects including foreshock and aftershock sequences, migration of foci, and the capacity to produce both characteristic and noncharacteristic earthquakes. Over a period of about 150 yr the complex interaction of fault segments and the nonlinear failure conditions conspire to transform an apparently deterministic model into a chaotic one.

Design and rapid prototyping of DLC coated fractal surfaces for tissue engineering applications

International Nuclear Information System (INIS)

Diaz-Lantada, A; Mosquera, A; Endrino, J L; Lafont, P

2010-01-01

Several medical devices (both implantable and for in vitro diagnosis) benefit greatly from having microtextured surfaces that help to improve and promote phenomena such as osteointegracion and cell / tissue growth on the surface of a device. Normally, the use of abrasives or chemical attacks are employed for obtaining such surface microtextures, however, it is sometimes difficult to precisely control the final surface characteristics (porosity, roughness, among others) and consequently the related biological aspects. In this work, we propose an alternative process based on the use of fractal surface models for designing special surfaces, which helps controlling the desired contact properties (from the design stage) in multiple applications within biomedical engineering, especially regarding tissue engineering tasks. Manufacturing can be directly accomplished by means of rapid prototyping technologies. This method supposes a focus change from a conventional 'top-down' to a more versatile 'bottom-up' approach. Finally, in order to improve the possible biological response, the surfaces of the designed devices were coated with hydrogen-free amorphous carbon (a-C) thin films, known to be highly biocompatible materials. The films were deposited at room temperature using the vacuum filter cathodic arc technique. Our first prototypes have helped verify the viability of the approach and to validate the design, manufacturing and coating processes.

Design and rapid prototyping of DLC coated fractal surfaces for tissue engineering applications

Energy Technology Data Exchange (ETDEWEB)

Diaz-Lantada, A; Mosquera, A; Endrino, J L; Lafont, P, E-mail: adiaz@etsii.upm.es

2010-11-01

Several medical devices (both implantable and for in vitro diagnosis) benefit greatly from having microtextured surfaces that help to improve and promote phenomena such as osteointegracion and cell / tissue growth on the surface of a device. Normally, the use of abrasives or chemical attacks are employed for obtaining such surface microtextures, however, it is sometimes difficult to precisely control the final surface characteristics (porosity, roughness, among others) and consequently the related biological aspects. In this work, we propose an alternative process based on the use of fractal surface models for designing special surfaces, which helps controlling the desired contact properties (from the design stage) in multiple applications within biomedical engineering, especially regarding tissue engineering tasks. Manufacturing can be directly accomplished by means of rapid prototyping technologies. This method supposes a focus change from a conventional 'top-down' to a more versatile 'bottom-up' approach. Finally, in order to improve the possible biological response, the surfaces of the designed devices were coated with hydrogen-free amorphous carbon (a-C) thin films, known to be highly biocompatible materials. The films were deposited at room temperature using the vacuum filter cathodic arc technique. Our first prototypes have helped verify the viability of the approach and to validate the design, manufacturing and coating processes.

Environmental waste site characterization utilizing aerial photographs, remote sensing, and surface geophysics

International Nuclear Information System (INIS)

Pope, P.; Van Eeckhout, E.; Rofer, C.; Baldridge, S.; Ferguson, J.; Jiracek, G.; Balick, L.; Josten, N.; Carpenter, M.

1996-01-01

Six different techniques were used to delineate 40 year old trench boundary at Los Alamos National Laboratory. Data from historical aerial photographs, a magnetic gradient survey, airborne multispectral and thermal infra-red imagery, seismic refraction, DC resistivity, and total field magnetometry were utilized in this process. Each data set indicated a southern and northern edge for the trench. Average locations and 95% confidence limits for each edge were determined along a survey line perpendicular to the trench. Trench edge locations were fairly consistent among all six techniques. Results from a modeling effort performed with the total magnetic field data was the least consistent. However, each method provided unique and complementary information, and the integration of all this information led to a more complete characterization of the trench boundaries and contents

Trench process and structure for backside contact solar cells with polysilicon doped regions

Science.gov (United States)

De Ceuster, Denis; Cousins, Peter John; Smith, David D.

2010-12-14