Evaluation of wettability of binders used in moulding sands

Directory of Open Access Journals (Sweden)

Hutera B.

2007-01-01

Full Text Available Binders used in moulding sand have the differential properties. One of the main parameters influencing on moulding sand properties is wettability of the sand grain by binding material. In the article some problems concerned with wettability evaluation have been presented and the importance of this parameter for quantity description of process occurring in system: binder- sand grain has been mentioned. The procedure of wetting angle measurement and operation of prototype apparatus for wettability investigation of different binders used in moulding sand have been described, as well as the results of wetting angle measurement for different binders at different conditions. The addition of little amount of proper diluent to binder results in the state of equilibrium reached almost immediately. Such addition can also reduce the value of equilibrium contact angle. The uniform distribution of binder on the surface of the sand grains and reducing of the required mixing time can be obtained. It has also a positive effect on the moulding sand strength.

Pattern formation - Instabilities in sand ripples

DEFF Research Database (Denmark)

Hansen, J. L.; v. Hecke, M.; Haaning, A.

2001-01-01

Sand ripples are seen below shallow wavy water and are formed whenever water oscillates over a bed of sand. Here we analyse the instabilities that can upset this perfect patterning when the ripples are subjected to large changes in driving amplitude or frequency, causing them to deform both...

Comparison of integral cross section values of several cross section libraries in the SAND-II format

International Nuclear Information System (INIS)

Zijp, W.L.; Nolthenius, H.J.

1976-09-01

A comparison of some integral cross-section values for several cross-section libraries in the SAND-II format is presented. The integral cross-section values are calculated with the aid of the spectrum functions for a Watt fission spectrum, a 1/E spectrum and a Maxwellian spectrum. The libraries which are considered here are CCC-112B, ENDF/B-IV, DETAN74, LAPENAS and CESNEF. These 5 cross-section libraries used have all the SAND-II format. Discrepancies between cross-sections in the different libraries are indicated but not discussed

CFD evaluation of erosion rate around a bridge near a sand dune

Science.gov (United States)

He, Wei; Huang, Ning; Dun, Hongchao; Wang, Wenbo

2017-04-01

This study performs a series of simulations through solving the Navier-Stokes equations and the RNG k-ε turbulence model to investigate the wind erosion rates around a bridge in a desert area with sand dunes. The digital elevation model of sand dunes and the bridge model are obtained respectively from hypsographic map and construction drawings. Through combining them into the CFD software of Fluent the simulation zone was formed. The data of wind speed obtained from field observation is fitted into a logarithm format, which was imported into Fluent model as a inlet wind speed condition. Then, the effect of Dun-Go railway on wind-blown sand movement of the neighbouring environment is simulated. The results exhibit that affected by both the sand dune and bridge, the flow field is in a complex condition. It is also shown that the bridge in upstream of the sand dune will not increase the sand transport rate intensively, but change both wind velocity gradient and turbulence kinetic energy over surface of sand dune. On the other hand, when the bridge is built downstream the sand dune, simulation results show that sand deposition rate would be decreased in reference region downstream the pier.

Evaluation of Augmented REality Sandtable (ARES) during Sand Table Construction

Science.gov (United States)

2018-01-01

sand table, ARES, resulted in significantly higher- quality ratings overall for the terrain model based on a global rating scale, as well as...dependent measures in this study. Sand Table Construction Score Card: A 5-point Likert scale was used to identify the accuracy and quality of required...reproduced on the sand table. The quality of the map reproduced was evaluated using standard procedures of the map-drawing paradigm, such as that

Log analysis in the shallow oil sands of the San Joaquin Valley, California

International Nuclear Information System (INIS)

Vohs, J.B.

1976-01-01

Many fields in the San Joaquin Valley of California produce oil from a depth of 2,500 ft or less. During the period of primary production in these fields, evaluation of potential pay intervals from logs was restricted to examination of ES logs and correlation. With the introduction of secondary and tertiary recovery techniques the need for more and better answers, more quickly available, became apparent. However, several log-analysis problems had to be resolved. Formation evaluation using well logs was complicated by the shaliness of the sand intervals, the low and variable salinity of the formation waters, and the presence of low-pressure-gas (depleted) zones in many of the shallow sands. Solutions to these problems have required more modern logging programs and interpretation techniques. Logs available for the evaluation of these sands are the dual induction-laterolog, the compensated formation density log, the compensated neutron log, and the microlaterolog or proximity log. With this suite of logs it is possible to determine the shale content, porosity, saturation in the flushed zone, and water saturation of the sand, and to locate the low-pressure-gas sands and depleted zones. In cases where freshwater and oil are interlayered, it is possible to tell which sands contain oil and which contain only water. Because a quick interpretation is required, wellsite techniques are called for. These will be described

Modeling the influence of storms on sand wave formation : A linear stability approach

NARCIS (Netherlands)

Campmans, G.H.P.; Roos, P.C.; de Vriend, H.J.; Hulscher, S.J.M.H.

2017-01-01

We present an idealized process-based morphodynamic model to study the effect of storms on sand wave formation. To this end, we include wind waves, wind-driven flow and, in addition to bed load transport, suspended load sediment transport. A linear stability analysis is applied to systematically

Evaluate of head loss, sediment value and copper removal in sand media (rapid sand filter

Directory of Open Access Journals (Sweden)

Daneshi Navab

2014-06-01

Full Text Available Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2 2014: 276-286

Numerical simulation of aeolian sand ripples

International Nuclear Information System (INIS)

Kang Liqiang; Guo Liejin

2004-01-01

With a new horizontal saltation displacement vector, a model is implemented to simulate the initiation and evolution of aeolian sand ripples. In the model, saltation distance considers the effects of surface height and slope. A linear stability analysis is also carried out for formation of sand ripples. The results show that, the model can be able to successfully reproduce sand ripples which can increase in scale by merging of small ripples. The linear stability analysis indicates that sand ripples appear when the relaxation rate parameter is below a threshold value and wind strength parameter is larger than a critical value. The results also verified that the formation of sand ripples is a self-organization process

Evaluation of the potential for reduction in well spacing of the Bakken sand pool, Court Field

Energy Technology Data Exchange (ETDEWEB)

Majcher, M.B.; Estrada, C.A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Nexen Inc., Calgary, AB (Canada); Archer, J.C. [Nexen Inc., Calgary, AB (Canada)

2005-11-01

For the past 15 years, the Court field has produced hydrocarbons from the Mississippian/Devonian middle Bakken sandstone reservoir. The formation is located in west central Saskatchewan and was deposited in a marine shelf environment and later reworked into tidally influenced sand ridges. Vertical wells and a waterflood recovery scheme have been used to produce heavy crude with an API gravity of 17. A better understanding of the reservoir behaviour is required in order to advance field development and maintain successful waterflood management. Three-dimensional seismic and well logs were used to map the structural complexity of the sand ridge. This study examined the feasibility of using production and seismic data to update and substantiate a simulation model which was used to evaluate downspace potential. Stratigraphic disparities were taken into account as discontinuous interbedded siltstones may be flow barriers that create anisotropy in the permeability zone. Grid orientation was altered to align axially with the permeability trends of the main sand ridge. This study also reviewed an earlier field simulation and generated an updated model. The potential to reduce well spacing was then identified and waterflood optimization of the middle Bakken reservoir was evaluated. It was concluded that the edges of the sand ridge and areas isolated from existing injectors have the greatest potential for infill drilling and additional water injection because of the high sinkhole density. It was noted that drilling edge regions with high oil saturations have a risk of low permeability zones, resulting in low production rates and the possibility of an ineffective waterflood scheme. Therefore, a successful waterflood in the edge zones would require injector-producer pairs in the equivalent sand facies. 4 refs., 36 figs.

Solid sand particle addition can enhance the production of resting cysts in dinoflagellates

Science.gov (United States)

Yang, Aoao; Hu, Zhangxi; Tang, Yingzhong

2018-03-01

Resting cysts are an important part of the life cycle for many harmful algal bloom-forming dinoflagellates, and play vital roles in the recurrence and geographical spread of harmful algal blooms. Numerous factors have been suggested to regulate the formation of resting cysts, although only a few have been proven to be significant. Cyst formation can be induced by adverse environmental conditions such as drastic changes in temperature, light, salinity, and nutrient levels, and by biological interactions. In this study, we evaluated the ability of an artificial factor (fine sand particles) to enhance the formation of resting cysts. Fine sand particles were added to cultures of dinoflagellates that are known to produce cysts. The addition of fine sand particles significantly increased both the production rate and final yield of cysts in cultures of Scrippsiella trochoidea, Biecheleria brevisulcata, and Levanderina fissa (= Gymnodinium fissum, Gyrodinium instriatum, Gyrodinium uncatenum). The largest increase in the final yield (107-fold) of cysts as a result of sand addition was in S. trochoidea. However, addition of fine sand particles did not induce cyst formation, or barely affected cyst formation, in Akashiwo sanguinea, Cochlodinium polykrikoides and Pheopolykrikos hartmannii, which are also known to be cyst-producing species. We speculated that addition of sand significantly increased the chances of cell collision, which triggered cyst formation. However, further research is required to test this idea. Importantly, our findings indicate that the addition of fine sand particles is a useful method to obtain a large quantity of cysts in a short time for laboratory studies or tests; for example, if a cyst viability test is being used to assess the effectiveness of ships' ballast water treatment.

Evaluation of multistage filtration to reduce sand filter exhaust activity

International Nuclear Information System (INIS)

Zippler, D.B.

1975-01-01

Air from the Savannah River Plant Fuel Reprocessing facilities is filtered through deep bed sand filters consisting of 8 1 / 2 feet of gravel and sand. These filters have performed satisfactorily for the past 18 years in maintaining radioactive release levels to a minimum. The apparent filter efficiency has been determined for many years by measurements of the quantity of radioactivity in the air stream before and after the filter. Such tests have indicated efficiencies of 99.9 percent or better. Even with sand filter efficiency approaching a single stage HEPA filter, new emphasis on further reduction in release of plutonium activity to the environment prompted a study to determine what value backup HEPA filtration could provide. To evaluate the specific effect additional HEPA filtration would have on the removal of Pu from the existing sand filter exhaust stream, a test was conducted by passing a sidestream of sand-filtered air through a standard 24 x 24 x 11 1 / 2 in. HEPA filter. Isokinetic air samples were withdrawn upstream and downstream of the HEPA filter and counted for alpha activity. Efficiency calculations indicated that backup HEPA filtration could be expected to provide an additional 99 percent removal of the Pu activity from the present sand-filter exhaust. (U.S.)

Potential building sand deposits in Songkhla province area

Directory of Open Access Journals (Sweden)

Kooptarnond, K.

2002-10-01

Full Text Available An investigation of potential building sand deposits in Songkhla province area subdivided them into four regions according to their accumulation in various alluvial plains, meanders throughout alluvial deposits and residual soils. Four selected deposits, were Rattaphum-Khuan Niang, U-Taphao river, Na Mom, and Chana-Thepha regions. Information obtained from these deposits revealed a good correlation between the geomorphological features as interpreted from aerial photographs and those identified from vertical electrical resistivity sounding results. Sand samples were analysed for their physical and chemical properties. Petrographic studies were also undertaken to characterize the composition types, texture and shapes. An overview of the sand properties was used them to be within the acceptable limits for building sand. However, relatively high organic impurities and soundness were found in sand from Khuan Niang and Na Mom deposits. The result indicated a potential reconnaissance mineral resource of about 46 square kilometres.A reserve evaluation for natural building sand was carried out by using Geographic Information System (GIS. Maps of the various parameters considered were constructed in digital database format with the aid of Arc/Info and ArcView software. Overlay mapping and buffer zone modules were performed to evaluate inferred resources of building sand. The key parameters of analysis included the distance from transportation, distance from streams, lithology and thickness of sand layers. The remaining inferred sand total was of about 386 million cubic metres or about 1,021 million metric tons was therefore estimated, of which 60 percent lies in the Rattaphum-Khuan Niang region and 40 percent in the other regions.

Influence green sand system by core sand additions

Directory of Open Access Journals (Sweden)

N. Špirutová

2012-01-01

Full Text Available Today, about two thirds of iron alloys casting (especially for graphitizing alloys of iron are produced into green sand systems with usually organically bonded cores. Separation of core sands from the green sand mixture is very difficult, after pouring. The core sand concentration increase due to circulation of green sand mixture in a closed circulation system. Furthermore in some foundries, core sands have been adding to green sand systems as a replacement for new sands. The goal of this contribution is: “How the green sand systems are influenced by core sands?”This effect is considered by determination of selected technological properties and degree of green sand system re-bonding. From the studies, which have been published yet, there is not consistent opinion on influence of core sand dilution on green sand system properties. In order to simulation of the effect of core sands on the technological properties of green sands, there were applied the most common used technologies of cores production, which are based on bonding with phenolic resin. Core sand concentration added to green sand system, was up to 50 %. Influence of core sand dilution on basic properties of green sand systems was determined by evaluation of basic industrial properties: moisture, green compression strength and splitting strength, wet tensile strength, mixture stability against staling and physical-chemistry properties (pH, conductivity, and loss of ignition. Ratio of active betonite by Methylene blue test was also determined.

Tailings dewatering in the oil sands

Energy Technology Data Exchange (ETDEWEB)

Longo, S.; Labelle, M. [Golder Paste Technology, Sudbury, ON (Canada); Wislesky, I. [Golder Associates Ltd., Calgary, AB (Canada)

2010-07-01

Alberta's Directive 074 was established to reduce fluid tailings produced during oil sands extraction processes. This PowerPoint presentation examined some of the dewatering strategies available for oil sands operators and provided recommendations for implementing a dewatering plan. Sites must be evaluated in order to determine their chemistry, mineralogy, and the total quantity of material to be handled. The availability of potential additives must also be considered. Process technologies must be selected in relation to the operator's depositional strategy. Each site will require its own unique dewatering and depositional strategy. Dewatering technologies include thickening; in-line flocculation; centrifuge; co-mingling; and various new technologies such as electro-osmosis. Laboratory testing programs include index tests, primary stream thickening, and mini-pilot plant testing. The performance of various testing formats was evaluated. Thickening and depositional techniques were reviewed. tabs., figs.

The physics of wind-blown sand and dust.

Science.gov (United States)

Kok, Jasper F; Parteli, Eric J R; Michaels, Timothy I; Karam, Diana Bou

2012-10-01

The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols. This paper presents an extensive review of the physics of wind-blown sand and dust on Earth and Mars. Specifically, we review the physics of aeolian saltation, the formation and development of sand dunes and ripples, the physics of dust aerosol emission, the weather phenomena that trigger dust storms, and the lifting of dust by dust devils and other small-scale vortices. We also discuss the physics of wind-blown sand and dune formation on Venus and Titan.

Evaluation of Small-Scale Laterally Loaded Monopiles in Sand

DEFF Research Database (Denmark)

Roesen, Hanne Ravn; Thomassen, Kristina; Sørensen, Søren Peder Hyldal

2011-01-01

In current designs of offshore wind turbines, monopiles are often used as foundation. The behaviour of the monopoles when subjected to lateral loading has not been fully investigated. In this paper the diameter effect on laterally loaded non-slender piles in sand is evaluated by means of results ...

Determination of stability of saturated sands of Bredasdorp and Varswater Formations: Koeberg nuclear power station

International Nuclear Information System (INIS)

De Witt, M.J.; Barker, O.B.

1985-01-01

The planning of the Koeberg nuclear power station was postulated on the basis of possible seismic ground movements of sufficient intensity to cause liquefaction of the sand overlying the bedrock. Where seismic instability may occur, it is normally necessary for the potentially liquefiable soils to be removed and replaced with a stable material. The site investigations were therefore designed to evaluate the soils parameters necessary for the safe excavation of sand. The properties of potential backfill materials were studied and requirements for selective stockpiling of material from the excavation defined

Geothermal resources: Frio Formation, Upper Texas Gulf Coast. Geological circular 76-3

Energy Technology Data Exchange (ETDEWEB)

Bebout, D.G.; Loucks, R.G.; Bosch, S.C.; Dorfman, M.H.

1976-01-01

Major sand trends were identified in the Frio Formation, Upper Texas Gulf Coast as part of the evaluation of its potential for producing geothermal energy. Electrical logs from 465 wells spaced 5 to 10 miles apart were used in the study. Maps illustrating total net sand and total sand percentage of the Frio Formation are included. It was found that subsurface fluid temperatures of greater than 250/sup 0/F occur in the Frio sand bodies up to 100 ft thick downdip of the high-sand trends. LA broad band in Brazoria and Galveston Counties was delineated as having geothermal potential. (JGB)

Study of formation constant of molybdophosphate and it's application in the product of xenotime sand, tooth and bone

International Nuclear Information System (INIS)

Samin; Lahagu, F.; Basuki, K. T.; Ernawati, F.

1996-01-01

The formation constant of molybdophosphate complex and it's application in the product of xenotime sand, tooth and bone have been studied by spectrophotometric method. The molybdophosphate complex were formed from reaction between phosphate and molybdate on several of pH in the strong acid condition (pH = 0.45 - 0.71) and several of phosphate mole fraction (0.01 - 0.08). The several of complex formation reactions were determined by matrix disintegration technique. Molybdophosphate complex were founded three forms i.e. (P 2 Mo 18 O 62 ) 6- or 9 MPA, (PMo 11 O 39 ) 7- or 11 MPA and (PMo 12 O 40 ) 3- or 12 MPA. The formation constant of (PMo 12 O 40 ) 3- complex was found β = 10 46.95 ± 10 3.7 , while for (P 2 Mo 18 O 62 ) 6- and (PMo 11 O 39 ) 7- were not detected. The application in samples were found the concentration of P in product of xenotime sand : 5.37±0.08 μg/ml, in canine-tooth: 10.40 - 19.49 % in cutting-tooth : 11.08 - 18.05 % and in bone 10.94 - 14.29 %. (author)

Technology unlocks tar sands energy

Energy Technology Data Exchange (ETDEWEB)

Law, C

1967-09-25

Tar sand processing technology has been developed primarily in the categories of extraction techniques and in-situ processing. In October, a $235 million venture into tar sand processing will be inspected by visitors from many points on the globe. A synthetic crude of premium quality will be flowing through a 16-in. pipeline from the Tar Island plant site of Great Canadian Oil Sands to Edmonton. This processing plant uses an extractive mining technique. The tar sand pay zone in this area averages approximately 150 ft in thickness with a 50-ft overburden. It has been estimated that the tar sands cannot be exploited when the formation thickness is less than 100 ft and overburden exceeds the same amount. This indicates that extraction techniques can only be used to recover approximately 15% of the tar sand deposits. An in-situ recovery technique developed by Shell of Canada is discussed in detail. In essence it is selective hydraulic fracturing, followed by the injection of emulsifying chemicals and steam.

The Geodiversity in Drift Sand Landscapes of The Netherlands

Science.gov (United States)

van den Ancker, Hanneke; Jungerius, Pieter Dirk; Riksen, Michel

2015-04-01

The authors carried out detailed field studies of more than twelve drift sand landscapes in The Netherlands. The objective of these studies was to restore Natura-2000 values by restoring the wind activity. Active drift sands occur almost exclusively in The Netherlands, Natura 2000 habitat 2330 'Inland dunes with open Corynephorus and Agrostis grasslands', for which reason our country is largely responsible for this European landscape. Active drift sands had almost disappeared for two reasons: first, the stabilization of the drift sands by air pollution, mainly nitrogen, which stimulates the growth of algae and grasses that initiate soil formation, and second, by the growth of forests surrounding the sands, which decreases the wind force. The restoration studies revealed differences in the geodiversity between and within the drift sand areas. Whereas the drift sands on geological and soil maps show as almost homogenous areas, they have in fact highly variable geo-conditions of which examples will be given. These geodiversity aspects concern differences in geomorphological structure, origin, sediments and age of the drift sands. Differences in wind and water erosion, trampling and soil formation add to the geodiversity within the drift sand areas. Especially in the primary stages of succession the differences in geodiversity are relevant for the Natura-2000 values. We discerned three main types of active sands. Firstly, the impressive drift sands with large parabolic dune structures, often consisting of series of interlocking parabolic dunes. They developed from the northeast towards the southwest, against the direction of the dominant wind, and must have taken centuries to develop. Small parts of these systems are still active, other parts show different degrees of soil formation. Their origin is still unclear but probably dates from medieval times (Heidinga, 1985, Jungerius & Riksen, 2008). Second are the drift sand areas with irregular hills from 0.5 to about 2

Fuzzy comprehensive evaluation-based disaster risk assessment of desertification in Horqin Sand Land, China.

Science.gov (United States)

Wang, Yongfang; Zhang, Jiquan; Guo, Enliang; Sun, Zhongyi

2015-02-03

Desertification is a typical disaster risk event in which human settlements and living environments are destroyed. Desertification Disaster Risk Assessment can control and prevent the occurrence and development of desertification disasters and reduce their adverse influence on human society. This study presents the methodology and procedure for risk assessment and zoning of desertification disasters in Horqin Sand Land. Based on natural disaster risk theory and the desertification disaster formation mechanism, the Desertification Disaster Risk Index (DDRI) combined hazard, exposure, vulnerability and restorability factors and was developed mainly by using multi-source data and the fuzzy comprehensive evaluation method. The results showed that high risk and middle risk areas account for 28% and 23% of the study area, respectively. They are distributed with an "S" type in the study area. Low risk and very low risk areas account for 21% and 10% of the study area, respectively. They are distributed in the west-central and southwestern parts. Very high risk areas account for 18% of the study area and are distributed in the northeastern parts. The results can be used to know the desertification disaster risk level. It has important theoretical and practical significance to prevention and control of desertification in Horqin Sand Land and even in Northern China.

Fuzzy Comprehensive Evaluation-Based Disaster Risk Assessment of Desertification in Horqin Sand Land, China

Directory of Open Access Journals (Sweden)

Yongfang Wang

2015-02-01

Full Text Available Desertification is a typical disaster risk event in which human settlements and living environments are destroyed. Desertification Disaster Risk Assessment can control and prevent the occurrence and development of desertification disasters and reduce their adverse influence on human society. This study presents the methodology and procedure for risk assessment and zoning of desertification disasters in Horqin Sand Land. Based on natural disaster risk theory and the desertification disaster formation mechanism, the Desertification Disaster Risk Index (DDRI combined hazard, exposure, vulnerability and restorability factors and was developed mainly by using multi-source data and the fuzzy comprehensive evaluation method. The results showed that high risk and middle risk areas account for 28% and 23% of the study area, respectively. They are distributed with an “S” type in the study area. Low risk and very low risk areas account for 21% and 10% of the study area, respectively. They are distributed in the west-central and southwestern parts. Very high risk areas account for 18% of the study area and are distributed in the northeastern parts. The results can be used to know the desertification disaster risk level. It has important theoretical and practical significance to prevention and control of desertification in Horqin Sand Land and even in Northern China.

Wind-blown sand on beaches: an evaluation of models

Science.gov (United States)

Sherman, Douglas J.; Jackson, Derek W. T.; Namikas, Steven L.; Wang, Jinkang

1998-03-01

Five models for predicting rates of aeolian sand transport were evaluated using empirical data obtained from field experiments conducted in April, 1994 at a beach on Inch Spit, Co. Kerry, Republic of Ireland. Measurements were made of vertical wind profiles (to derive shear velocity estimates), beach slope, and rates of sand transport. Sediment samples were taken to assess characteristics of grain size and surface moisture content. Estimates of threshold shear velocity were derived using grain size data. After parsing the field data on the basis of the quality of shear velocity estimation and the occurrence of blowing sand, 51 data sets describing rates of sand transport and environmental conditions were retained. Mean grain diameter was 0.17 mm. Surface slopes ranged from 0.02 on the foreshore to about 0.11 near the dune toe. Mean shear velocities ranged from 0.23 m s -1 (just above the observed transport threshold) to 0.65 m s -1. Rates of transport ranged from 0.02 kg m -1 h -1 to more than 80 kg m -1 h -1. These data were used as input to the models of Bagnold [Bagnold, R.A., 1936. The Movement of Desert Sand. Proc. R. Soc. London, A157, 594-620], Kawamura [Kawamura, R., 1951. Study of Sand Movement by Wind. Translated (1965) as University of California Hydraulics Engineering Laboratory Report HEL 2-8, Berkeley], Zingg [Zingg, A.W., 1953. Wind tunnel studies of the movement of sedimentary material. Proc. 5th Hydraulics Conf. Bull. 34, Iowa City, Inst. of Hydraulics, pp. 111-135], Kadib [Kadib, A.A., 1965. A function for sand movement by wind. University of California Hydraulics Engineering Laboratory Report HEL 2-8, Berkeley], and Lettau and Lettau [Lettau, K. and Lettau, H., 1977. Experimental and Micrometeorological Field Studies of Dune Migration. In: K. Lettau and H. Lettau (Eds.), Exploring the World's Driest Climate. University of Wisconsin-Madison, IES Report 101, pp. 110-147]. Correction factors to adjust predictions of the rate of transport to account

Evaluation of methods to sample fecal indicator bacteria in foreshore sand and pore water at freshwater beaches.

Science.gov (United States)

Vogel, Laura J; Edge, Thomas A; O'Carroll, Denis M; Solo-Gabriele, Helena M; Kushnir, Caitlin S E; Robinson, Clare E

2017-09-15

Fecal indicator bacteria (FIB) are known to accumulate in foreshore beach sand and pore water (referred to as foreshore reservoir) where they act as a non-point source for contaminating adjacent surface waters. While guidelines exist for sampling surface waters at recreational beaches, there is no widely-accepted method to collect sand/sediment or pore water samples for FIB enumeration. The effect of different sampling strategies in quantifying the abundance of FIB in the foreshore reservoir is unclear. Sampling was conducted at six freshwater beaches with different sand types to evaluate sampling methods for characterizing the abundance of E. coli in the foreshore reservoir as well as the partitioning of E. coli between different components in the foreshore reservoir (pore water, saturated sand, unsaturated sand). Methods were evaluated for collection of pore water (drive point, shovel, and careful excavation), unsaturated sand (top 1 cm, top 5 cm), and saturated sand (sediment core, shovel, and careful excavation). Ankle-depth surface water samples were also collected for comparison. Pore water sampled with a shovel resulted in the highest observed E. coli concentrations (only statistically significant at fine sand beaches) and lowest variability compared to other sampling methods. Collection of the top 1 cm of unsaturated sand resulted in higher and more variable concentrations than the top 5 cm of sand. There were no statistical differences in E. coli concentrations when using different methods to sample the saturated sand. Overall, the unsaturated sand had the highest amount of E. coli when compared to saturated sand and pore water (considered on a bulk volumetric basis). The findings presented will help determine the appropriate sampling strategy for characterizing FIB abundance in the foreshore reservoir as a means of predicting its potential impact on nearshore surface water quality and public health risk. Copyright © 2017 Elsevier Ltd. All rights

Mapping the productive sands of Lower Goru Formation by using seismic stratigraphy and rock physical studies in Sawan area, southern Pakistan: A case study

KAUST Repository

Munir, K.

2011-02-24

This study has been conducted in the Sawan gas field located in southern Pakistan. The aim of the study is to map the productive sands of the Lower Goru Formation of the study area. Rock physics parameters (bulk modulus, Poisson\\'s ratio) are analysed after a detailed sequence stratigraphic study. Sequence stratigraphy helps to comprehend the depositional model of sand and shale. Conformity has been established between seismic stratigraphy and the pattern achieved from rock physics investigations, which further helped in the identification of gas saturation zones for the reservoir. Rheological studies have been done to map the shear strain occurring in the area. This involves the contouring of shear strain values throughout the area under consideration. Contour maps give a picture of shear strain over the Lower Goru Formation. The identified and the productive zones are described by sands, high reflection strengths, rock physical anomalous areas and low shear strain.

Technical review of WSRC-TR-93-614 criticality safety evaluation for disassembly basin sand filter

International Nuclear Information System (INIS)

Reed, R.L.

1994-01-01

The study documented in WSRC-TR-93-614 performed an evaluation of the criticality potential associated with the Disassembly Basin Sand Filter for K and L Areas. The document reviewed incorporated results of calculations documented in the engineering calculation N-CLC-K-00151. Analyses of the contents of disassembly basin sludge has indicated that the sludge contains fissile material in excess of subcritical mass limits as specified in ANSI/ANS standards. Previous studies had determined that the fissile material can not collect into a critical configuration in the basin. Since the sand filter is intended to remove suspended particles from the basin water and could serve as a mechanism to collect the fissile material into a critical configuration, the study examined conditions under which criticality could occur in the sand filter. The study shows that criticality is not considered possible in the sand filter. This review emphasized the technical accuracy and presentation of the evaluation. The evaluation was also examined for the elements required for NCSEs. The review was performed in accordance with the NRTSC technical review requirements and procedures and the E7 Manual technical review requirements. The technical review (per the E7 manual) of the engineering calculation (N-CLC-K-0 1 5 1) was previously performed by this reviewer

Differentiation of Palaeogene sand by glauconitic and geochemical fingerprinting, Siri Canyon, Danish North Sea

Energy Technology Data Exchange (ETDEWEB)

Olivarius, M.; Knudsen, Christian; Svendsen, Johan B.

2011-07-01

The submarine Siri Canyon is NE-SW-oriented and located in the Danish North Sea. It contains a number of oil reservoirs with glauconite-rich sand. The reservoirs of interest in the Nini oil field are the Late Paleocene Tyr Member of the Lista Formation and the Kolga Member of the Sele Formation, presumably of Early Eocene age. These members have previously been known as the Ty and Hermod members. The sand shows signs of injection, both in cores and in seismic data. The aim of this work is to chemically characterise and fingerprint the sand in order to reveal the origin of the sand found in three horizontal wells, which could have been injected from one or both of the Tyr and Kolga members. Core samples were collected from two vertical wells of known stratigraphy to make a basis of comparison, whereas samples of the cuttings were collected from the three horizontal wells with ages primarily corresponding to the Kolga Member. The purpose was moreover to evaluate whether cuttings samples can be used for fingerprinting as an alternative to core samples. The interest in discriminating between the ages of the injected sand is the fact that the reservoir properties (porosity and permeability) are largely controlled by the original composition of the sand. Consequently, results from this study could affect the property modelling of the field. (LN)

Oil sands tailings leachability and toxicity evaluation

International Nuclear Information System (INIS)

Gulley, J.R.

1995-01-01

Fine tailings disposal and reclamation is a major issue facing the oil sands mining and extraction industry. Government regulations dictate that reclamation must return the site to a level of self-sustaining biological capability which approximates the natural condition. A two-phase laboratory program has been completed to investigate the suitability of alternative reclamation materials. For the first phase of the study, chemical and toxicological analyses were carried out on 13 different reclamation and reference materials (solid phase and extractions). Seedling emergence, nematode maturation, algal growth and bacterial luminescence for leachate samples showed a range of sensitivities in response to the tested materials, although phytotoxicity tests were generally the most sensitive. With the exception of one test material, high toxicity ratings were consistent with that expected from the chemical data. The second phase of the study focused on the evaluation of chemical and toxicological conditions in leachate water generated using bench-scale column percolation tests. Leachate water equivalent to 10 pore volume replacements was generated and temporal variations in toxicity and chemistry monitored. Similar to phase 1 findings, phytotoxicity tests were the most sensitive tests to leachate waters. For most materials tested, most toxicity was removed after 2--3 porewater replacements. More persistent toxicity was noted for samples containing bitumen (e.g., fine tails and oil sands). No clear correspondence was noted between chemical concentrations and toxicity in leachate waters

Appraisal of the tight sands potential of the Sand Wash and Great Divide Basins

International Nuclear Information System (INIS)

1993-08-01

The volume of future tight gas reserve additions is difficult to estimate because of uncertainties in the characterization and extent of the resource and the performance and cost-effectiveness of stimulation and production technologies. Ongoing R ampersand D by industry and government aims to reduce the risks and costs of producing these tight resources, increase the certainty of knowledge of their geologic characteristics and extent, and increase the efficiency of production technologies. Some basins expected to contain large volumes of tight gas are being evaluated as to their potential contribution to domestic gas supplies. This report describes the results of one such appraisal. This analysis addresses the tight portions of the Eastern Greater Green River Basin (Sand Wash and Great Divide Subbasins in Northwestern Colorado and Southwestern Wyoming, respectively), with respect to estimated gas-in-place, technical recovery, and potential reserves. Geological data were compiled from public and proprietary sources. The study estimated gas-in-place in significant (greater than 10 feet net sand thickness) tight sand intervals for six distinct vertical and 21 areal units of analysis. These units of analysis represent tight gas potential outside current areas of development. For each unit of analysis, a ''typical'' well was modeled to represent the costs, recovery and economics of near-term drilling prospects in that unit. Technically recoverable gas was calculated using reservoir properties and assumptions about current formation evaluation and extraction technology performance. Basin-specific capital and operating costs were incorporated along with taxes, royalties and current regulations to estimate the minimum required wellhead gas price required to make the typical well in each of unit of analysis economic

Adhesion to sand and ability to mineralise low pesticide concentrations are required for efficient bioaugmentation of flow-through sand filters

DEFF Research Database (Denmark)

Samuelsen, Elin Djurhuus; Badawi, Nora; Nybroe, Ole

2017-01-01

(Sphingomonas sp. PM2, Sphingomonas sp. ERG5, Burkholderia sp. TFD34, Cupriavidus sp. TFD38) were characterised with regard to their motility, cell surface hydrophobicity, biofilm formation, adhesion behaviour and ability to mineralise MCPA. Strains PM2 and ERG5 were non-motile and hydrophobic, whilst strains...... TFD34 and TFD38 were motile and less hydrophobic. All the strains except ERG5 showed low biofilm formation on polystyrene, although it was significantly higher on glass. PM2 was the most efficient MCPA degrader as it displayed no lag phase and reached >50 % mineralisation at all concentrations (0.......0016-25 mg L(-1)). PM2 adhered significantly better to sand than the other strains. No link was found between motility, biofilm formation and the ability to adhere to sand. PM2 completely removed MCPA for 14 days when inoculated in sand columns with a constant inlet of 1 mg L(-1) MCPA. These results...

Policy Analysis of the Canadian Oil Sands Experience

Energy Technology Data Exchange (ETDEWEB)

None, None

2013-09-01

For those who support U.S. oil sands development, the Canadian oil sands industry is often identified as a model the U.S. might emulate, yielding financial and energy security benefits. For opponents of domestic oil sands development, the Canadian oil sands experience illustrates the risks that opponents of development believe should deter domestic policymakers from incenting U.S. oil sands development. This report does not seek to evaluate the particular underpinnings of either side of this policy argument, but rather attempts to delve into the question of whether the Canadian experience has relevance as a foundational model for U.S. oil sands development. More specifically, this report seeks to assess whether and how the Canadian oil sands experience might be predictive or instructive in the context of fashioning a framework for a U.S. oil sands industry. In evaluating the implications of these underpinnings for a prospective U.S. oil sands industry, this report concentrates on prospective development of the oil sands deposits found in Utah.

Use of sand wave habitats by silver hake

Science.gov (United States)

Auster, P.J.; Lindholm, J.; Schaub, S.; Funnell, G.; Kaufman, L.S.; Valentine, P.C.

2003-01-01

Silver hake Merluccius bilinearis are common members of fish communities in sand wave habitats on Georges Bank and on Stellwagen Bank in the Gulf of Maine. Observations of fish size v. sand wave period showed that silver hake are not randomly distributed within sand wave landscapes. Regression analyses showed a significant positive relationship between sand wave period and fish length. Correlation coefficients, however, were low, suggesting other interactions with sand wave morphology, the range of current velocities, and available prey may also influence their distribution. Direct contact with sand wave habitats varied over diel periods, with more fish resting on the seafloor during daytime than at night. Social foraging, in the form of polarized groups of fish swimming in linear formations during crepuscular and daytime periods, was also observed. Sand wave habitats may provide shelter from current flows and mediate fish-prey interactions. ?? 2003 The Fisheries Society of the British Isles.

Sedimentary controls on modern sand grain coat formation

Science.gov (United States)

Dowey, Patrick J.; Worden, Richard H.; Utley, James; Hodgson, David M.

2017-05-01

Coated sand grains can influence reservoir quality evolution during sandstone diagenesis. Porosity can be reduced and fluid flow restricted where grain coats encroach into pore space. Conversely pore-lining grain coats can restrict the growth of pore-filling quartz cement in deeply buried sandstones, and thus can result in unusually high porosity in deeply buried sandstones. Being able to predict the distribution of coated sand grains within petroleum reservoirs is thus important to help find good reservoir quality. Here we report a modern analogue study of 12 sediment cores from the Anllóns Estuary, Galicia, NW Spain, collected from a range of sub-environments, to help develop an understanding of the occurrence and distribution of coated grains. The cores were described for grain size, bioturbation and sedimentary structures, and then sub-sampled for electron and light microscopy, laser granulometry, and X-ray diffraction analysis. The Anllóns Estuary is sand-dominated with intertidal sand flats and saltmarsh environments at the margins; there is a shallowing/fining-upwards trend in the estuary-fill succession. Grain coats are present in nearly every sample analysed; they are between 1 μm and 100 μm thick and typically lack internal organisation. The extent of grain coat coverage can exceed 25% in some samples with coverage highest in the top 20 cm of cores. Samples from muddy intertidal flat and the muddy saltmarsh environments, close to the margins of the estuary, have the highest coat coverage (mean coat coverage of 20.2% and 21.3%, respectively). The lowest mean coat coverage occurs in the sandy saltmarsh (10.4%), beyond the upper tidal limit and sandy intertidal flat environments (8.4%), close to the main estuary channel. Mean coat coverage correlates with the concentration of clay fraction. The primary controls on the distribution of fine-grained sediment, and therefore grain coat distribution, are primary sediment transport and deposition processes that

The importance of sand in the formation of avulsion channels within experimental fans that develop from sediment mixtures of mud and sand

Science.gov (United States)

Iscen, N.; Strom, K.

2017-12-01

Autogenic channel migration and avulsion has long been recognized as important drivers of alluvial fan dynamics. In the literature, several field studies have documented that the presence and the amount of sand transport through a channel is important for channel incision in alluvial fans and deltas. In our experiments, we present the general autogenic avulsion cycle of experimental alluvial fans with mixtures of cohesive sediment and sand with a range of boundary conditions, and we detail the importance of mobile sand fraction in the development of channels that lead to avulsion. Experimental observations demonstrate that new channels form at topographically low regions within the floodplain providing that sand is transported to these topographic lows due to overbank flow or levee breaching. In addition to the sediment transported from upstream, erosion of a previous deposit and an ongoing backfilling nearby are observed as the possible sources of sand getting into the ghost channels. We explore whether the presence of sand is important for channel development because it increases abrasion of the channel or because it changes the roughness characteristics of the flow. We also examine the affect of sediment and water supply change on the newly described channelization process and link distinctive channel morphologies to different stages of described channel development and the avulsion process.

Study of Black Sand Particles from Sand Dunes in Badr, Saudi Arabia Using Electron Microscopy

Directory of Open Access Journals (Sweden)

Haider Abbas Khwaja

2015-08-01

Full Text Available Particulate air pollution is a health concern. This study determines the microscopic make-up of different varieties of sand particles collected at a sand dune site in Badr, Saudi Arabia in 2012. Three categories of sand were studied: black sand, white sand, and volcanic sand. The study used multiple high resolution electron microscopies to study the morphologies, emission source types, size, and elemental composition of the particles, and to evaluate the presence of surface “coatings or contaminants” deposited or transported by the black sand particles. White sand was comprised of natural coarse particles linked to wind-blown releases from crustal surfaces, weathering of igneous/metamorphic rock sources, and volcanic activities. Black sand particles exhibited different morphologies and microstructures (surface roughness compared with the white sand and volcanic sand. Morphological Scanning Electron Microscopy (SEM and Laser Scanning Microscopy (LSM analyses revealed that the black sand contained fine and ultrafine particles (50 to 500 nm ranges and was strongly magnetic, indicating the mineral magnetite or elemental iron. Aqueous extracts of black sands were acidic (pH = 5.0. Fe, C, O, Ti, Si, V, and S dominated the composition of black sand. Results suggest that carbon and other contaminant fine particles were produced by fossil-fuel combustion and industrial emissions in heavily industrialized areas of Haifa and Yanbu, and transported as cloud condensation nuclei to Douf Mountain. The suite of techniques used in this study has yielded an in-depth characterization of sand particles. Such information will be needed in future environmental, toxicological, epidemiological, and source apportionment studies.

Bioaugmentation of flow-through sand filters

DEFF Research Database (Denmark)

Samuelsen, Elin Djurhuus

for degradation performances in flow-through sand columns, with the aim of identifying a suitable inoculant strain for future environmental applications. Another aim was to identify a suitable genetic marker to monitor phenoxy acid degradation in strain Sphingobium sp. PM2. We were not able to link motility...... and biofilm formation to the strains´ ability to adhere to sand. Nevertheless, a correlation was found between cell surface hydrophobicity and adhesion and overall degradation performances in flow-through sand columns. We identified S phingobium sp. PM2 as a promising inoculant strain, displaying efficient...... MCPA degradation for prolonged periods in flow-through sand columns. In an expression study of catabolic genes with putative roles in phenoxy acid degradation, we observed a marked upregulation of catabolic genes cadA and tfdC upon exposure to MCPA, 2,4-D, dichlorprop and mecoprop in strain PM2, which...

Oil sands to the rescue: oil sand microbial communities can degrade recalcitrant alkyl phenyl alkanoic acids

Energy Technology Data Exchange (ETDEWEB)

Whitby, Corinne [University of Essex (Canada)], email: cwhitby@essex.ac.uk

2011-07-01

Almost half of all global oil reserves are found as biodegraded heavy oils found in vast tar sand deposits located in North and South America and these account for 47% of Canadian oil production. Oil sand extraction generates large amounts of toxic waste water, known as oil sand process waters (OSPW), that are stored in large tailing ponds that contain toxic compounds like naphthenic acids (NAs). The presence of NAs creates problems like toxicity, corrosion, and the formation of calcium napthenate deposits which block pipelines and other infrastructure and need to be removed. This paper presents oil sand microbial communities that can degrade these NAs. The approach is to apply new aliphatic and aromatic NAs as substrates to supplement and identify NA degrading microbes and also to identify the metabolites produced and explain NA degradation pathways and the functional genes involved. The chemistry and the processes involved are explained. From the results, it is suggested that pure cultures of P. putida KT2440 be used against NAs.

Sand box experiments with bioclogging of porous media: Hydraulic conductivity reductions

DEFF Research Database (Denmark)

Seifert, Dorte; Engesgaard, Peter

2012-01-01

Tracer experiments during clogging and de-clogging experiments in a 2D sand box were via an image analysis used to establish a data set on the relation between changes in hydraulic conductivity (K) and relative porosity (β). Clogging appears to create a finger-like tracer transport, which could...... and closer to the substrate source during the experiments suggesting that the zone of clogging moved upstream. Three clogging models, K(β), from the literature were tested for their ability to describe the temporal changes in clogging at the scale of the sand box; the model of Clement et al. (1996......) that makes no assumption on biomass distribution, the plug formation model of Thullner et al. (2002a), and the biofilm-plug formation model of Vandevivere (1995). The plug formation and biofilm-plug formation models both match the observed changes between the hydraulic conductivity of the sand box...

Formation evaluation of fractured basement, Cambay Basin, India

International Nuclear Information System (INIS)

Gupta, Saurabh Datta; Farooqui, M Y; Chatterjee, Rima

2012-01-01

Unconventional reservoirs such as fractured basalts, shale gas and tight sand are currently playing an important role in producing a significant amount of hydrocarbon. The Deccan Trap basaltic rocks form the basement of the Cambay Basin, India, and hold commercially producible hydrocarbon. In this study two wells drilled through fractured basalts are chosen for evaluating the lithology, porosity and oil saturation of the reservoir sections. Well logs, such as gamma ray, high resolution resistivity, litho density, compensated neutron and elemental capture spectroscopy, have been used in cross-plotting techniques for lithology and mineral identification. Formation micro imagery log data have been analysed to quantify the fractures and porosity in the fractured reservoirs for a well in the south Ahmedabad block of the Cambay Basin. The results of the analysis of two wells are presented and discussed and they are found to be in good agreement with geological and production data. (paper)

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Directory of Open Access Journals (Sweden)

Yoko eOhtomo

2013-12-01

Full Text Available Geological CO2 sequestration in unmineable subsurface oil/gas fields and coal formations has been proposed as a means of reducing anthropogenic greenhouse gasses in the atmosphere. However, the feasibility of injecting CO2 into subsurface depends upon a variety of geological and economic conditions, and the ecological consequences are largely unpredictable. In this study, we developed a new flow-through-type reactor system to examine potential geophysical, geochemical and microbiological impacts associated with CO2 injection by simulating in situ pressure (0–100 MPa and temperature (0–70°C conditions. Using the reactor system, anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively were continuously supplemented into a column comprised of bituminous coal and sand under a pore pressure of 40 MPa (confined pressure: 41 MPa at 40°C for 56 days. 16S rRNA gene analysis of the bacterial components showed distinct spatial separation of the predominant taxa in the coal and sand over the course of the experiment. Cultivation experiments using sub-sampled fluids revealed that some microbes survived, or were metabolically active, under CO2-rich conditions. However, no methanogens were activated during the experiment, even though hydrogenotrophic and methylotrophic methanogens were obtained from conventional batch-type cultivation at 20°C. During the reactor experiment, the acetate and methanol concentration in the fluids increased while the δ13Cacetate, H2 and CO2 concentrations decreased, indicating the occurrence of homo-acetogenesis. 16S rRNA genes of homo-acetogenic spore-forming bacteria related to the genus Sporomusa were consistently detected from the sandstone after the reactor experiment. Our results suggest that the injection of CO2 into a natural coal-sand formation preferentially stimulates homo-acetogenesis rather than methanogenesis, and that this process is accompanied by biogenic CO2 conversion to

Supercritical solvent extraction of oil sand bitumen

Science.gov (United States)

Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

2017-08-01

The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

Experimental investigation of sanding propensity for the Andrew completion

Energy Technology Data Exchange (ETDEWEB)

Venkitaraman, A.; Li, H. [Schlumberger Perforating and Testing Center (United Kingdom); Leonard, A. J.; Bowden, P. R. [BP Exploration (United Kingdom)

1998-12-31

A series of laboratory experiments were performed on three reservoir core samples selected from two plot wells to confirm the likelihood of sand production during the completion phase of the planned Andrew horizontal wells, and to perform risk analysis of formation failure at the time of underbalance perforation, and expected producing conditions. CT scans revealed no perforation failure, and the core samples did not show any propensity to produce sand during single-phase oil flow. Transient sand production was observed when water cut was introduced, but sand production declined as the percentage of water cut was increased. There was no evidence of sand production in the core samples during depletion testing either, and the wells were subsequently completed with perforated cemented liners without sand control. No sand problems have been encountered in two years of production, with some wells in water cut and declined reservoir pressure of 200 psi. 8 refs., 3 tabs., 5 figs.

Effects of sand burial on dew deposition on moss soil crust in a revegetated area of the Tennger Desert, Northern China

Science.gov (United States)

Jia, Rong-liang; Li, Xin-rong; Liu, Li-chao; Pan, Yan-xia; Gao, Yan-hong; Wei, Yong-ping

2014-11-01

Sand burial and dew deposition are two fundamental phenomena profoundly influencing biological soil crusts in desert areas. However, little information is available regarding the effects of sand burial on dew deposition on biological soil crusts in desert ecosystems. In this study, we evaluated the effects of sand burial at depths of 0 (control), 0.5, 1, 2 and 4 mm on dew formation and evaporation of three dominant moss crusts in a revegetated area of the Tengger Desert (Northern China) in 2010. The results revealed that sand burial significantly decreased the amount of dew deposited on the three moss crust types by acting as a semi-insulator retarding the dew formation and evaporation rates. The changes in surface temperature cannot fully explain the variations of the formation and evaporation rates of dew by moss crusts buried by sand. The extension of dew retention time was reflected by the higher dew ratios (the ratio of dew amount at a certain time to the maximum value in a daily course) in the daytime, and may to some extent have acted as compensatory mechanisms that diminished the negative effects of the reduction of dew amount induced by sand burial of moss crusts. The resistances to reduction of dewfall caused by sand burial among the three moss crusts were also compared and it was found that Bryum argenteum crust showed the highest tolerance, followed by crusts dominated by Didymodon vinealis and Syntrichia caninervis. This sequence corresponds well with the successional order of the three moss crusts in the revegetated area, thereby suggesting that resistance to reduction of dewfall may act as one mechanism by which sand burial drives the succession of moss crusts in desert ecosystems. This side effect of dew reduction induced by sand burial on biological soil crusts should be considered in future ecosystem construction and management of desert area.

Tidal dynamics in the sand motor lagoon

NARCIS (Netherlands)

De Vries, S.; Radermacher, M.; De Schipper, M.A.; Stive, M.J.F.

2015-01-01

The Sand Motor is a mega-nourishment characterized by a very large sand volume of around 20 million m3 placed along the Dutch coast. The Sand Motor is a pilot project to evaluate the performance of an alternative nourishment strategy with respect to different functions of the coastal system. Within

Road dust from pavement wear and traction sanding

Energy Technology Data Exchange (ETDEWEB)

Kupiainen, K.

2007-07-01

Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is 'road dust'. The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: (i) How do traction

Aging effects on oil-contaminated Kuwaiti sand

International Nuclear Information System (INIS)

Al-Sanad, H.A.; Ismael, N.F.

1997-01-01

Large quantities of oil-contaminated sands resulted from the destruction of oil wells and the formation of oil lakes in Kuwait at the end of the Gulf Wa/r. A laboratory testing program was carried out to determine the geotechnical properties of this material and the effect of aging on their properties. Tests included direct shear, triaxial, and consolidation tests on clean and contaminated sand at the same relative density. The influence of aging was examined by testing uncontaminated sand after aging for one, three, and six months in natural environmental conditions. The results indicated increased strength and stiffness due to aging and a reduction of the oil content due to evaporation of volatile compounds. The factors that influence the depth of oil penetration in compacted sand columns were also examined including the type of oil, relative density, and the amount of fines

Evaluating the oil sands reclamation process: Assessing policy capacity and stakeholder access for government and non-governmental organizations operating in Alberta's oil sands

Science.gov (United States)

Patterson, Tyler

. In an effort to discern the overall status of reclamation in the oil sands this study explores several factors essential to policy capacity: work environment, training, employee attitudes, perceived capacity, policy tools, evidence based work, and networking. Data was collected through key informant interviews with senior policy professionals in government and non-government agencies in Alberta. The following are agencies of interest in this research: Canadian Association of Petroleum Producers (CAPP); Alberta Environment and Sustainable Resource Development (AESRD); Alberta Energy Regulator (AER); Cumulative Environmental Management Association (CEMA); Alberta Environment Monitoring, Evaluation, and Reporting Agency (AEMERA); Wood Buffalo Environmental Association (WBEA). The aim of this research is to explain how and why reclamation policy is conducted in Alberta's oil sands. This will illuminate government capacity, NGO capacity, and the interaction of these two agency typologies. In addition to answering research questions, another goal of this project is to show interpretive analysis of policy capacity can be used to measure and predict policy effectiveness. The oil sands of Alberta will be the focus of this project, however, future projects could focus on any government policy scenario utilizing evidence-based approaches.

Sand waves on an epicontinental shelf: Northern Bering Sea

Science.gov (United States)

Field, M.E.; Nelson, C.H.; Cacchione, D.A.; Drake, D.E.

1981-01-01

Sand waves and current ripples occupy the crests and flanks of a series of large linear sand ridges (20 km ?? 5 km ?? 10 m high) lying in an open-marine setting in the northern Bering Sea. The sand wave area, which lies west of Seward Peninsula and southeast of Bering Strait, is exposed to the strong continuous flow of coastal water northward toward Bering Strait. A hierarchy of three sizes of superimposed bedforms, all facing northward, was observed in successive cruises in 1976 and 1977. Large sand waves (height 2 m; spacing 200 m) have smaller sand waves (height 1 m; spacing 20 m) lying at a small oblique angle on their stoss slopes. The smaller sand waves in turn have linguoid ripples on their stoss slopes. Repeated studies of the sand wave fields were made both years with high-resolution seismic-reflection profiles, side-scan sonographs, underwater photographs, current-meter stations, vibracores, and suspended-sediment samplers. Comparison of seismic and side-scan data collected along profile lines run both years showed changes in sand wave shape that indicate significant bedload transport within the year. Gouge marks made in sediment by keels of floating ice also showed significantly different patterns each year, further documenting modification to the bottom by sediment transport. During calm sea conditions in 1977, underwater video and camera observations showed formation and active migration of linguoid and straight-crested current ripples. Current speeds 1 m above the bottom were between 20 and 30 cm/s. Maximum current velocities and sand wave migration apparently occur when strong southwesterly winds enhance the steady northerly flow of coastal water. Many cross-stratified sand bodies in the geologic record are interpreted as having formed in a tidal- or storm-dominated setting. This study provides an example of formation and migration of large bedforms by the interaction of storms with strong uniform coastal currents in an open-marine setting. ?? 1981.

Biological CO2 conversion to acetate in subsurface coal-sand formation using a high-pressure reactor system

Science.gov (United States)

Ohtomo, Y.; Ijiri, A.; Ikegawa, Y.; Tsutsumi, M.; Imachi, H.; Uramoto, G.; Hoshino, T.; Morono, Y.; Tanikawa, W.; Hirose, T.; Inagaki, F.

2013-12-01

The geological CO2 sequestration into subsurface unmineable oil/gas fields and coal formations has been considered as one of the possible ways to reduce dispersal of anthropogenic greenhouse gasses into the atmosphere. However, feasibility of CO2 injection largely depends on a variety of geological and economical settings, and its ecological consequences have remained largely unpredictable. To address these issues, we developed a new flow-through-type CO2 injection system designated as the 'geobio-reactor system' to examine possible geophysical, geochemical and microbiological impact caused by CO2 injection under in-situ pressure (0-100 MPa) and temperature (0-70°C) conditions. In this study, we investigated Eocene bituminous coal-sandstones in the northwestern Pacific coast, Hokkaido, Japan, using the geobio-reactor system. Anaerobic artificial fluid and CO2 (flow rate: 0.002 and 0.00001 mL/min, respectively) were continuously supplemented into the coal-sand column under the pore pressure of 40 MPa (confined pressure: 41 MPa) at 40°C for 56 days. Molecular analysis of bacterial 16S rRNA genes showed that predominant bacterial components were physically dispersed from coal to sand as the intact form during experiment. Cultivation experiments from sub-sampling fluids indicated that some terrestrial microbes could preserve their survival in subsurface condition. Molecular analysis of archaeal 16S rRNA genes also showed that no methanogens were activated during experiment. We also anaerobically incubated the coal sample using conventional batch-type cultivation technique with a medium for methanogens. After one year of the batch incubation at 20°C, methane could be detected from the cultures except for the acetate-fed culture. The sequence of archaeal 16S rRNA genes via PCR amplification obtained from the H2 plus formate-fed culture was affiliated with a hydrogenotrophic methanogen within the genus Methanobacterium, whereas the methanol plus trimethylamine culture

Mapping the productive sands of Lower Goru Formation by using seismic stratigraphy and rock physical studies in Sawan area, southern Pakistan: A case study

KAUST Repository

Munir, K.; Iqbal, M.A.; Farid, A.; Shabih, S.M.

2011-01-01

This study has been conducted in the Sawan gas field located in southern Pakistan. The aim of the study is to map the productive sands of the Lower Goru Formation of the study area. Rock physics parameters (bulk modulus, Poisson's ratio

TCE degradation in groundwater by chelators-assisted Fenton-like reaction of magnetite: Sand columns demonstration.

Science.gov (United States)

Jia, Daqing; Sun, Sheng-Peng; Wu, Zhangxiong; Wang, Na; Jin, Yaoyao; Dong, Weiyang; Chen, Xiao Dong; Ke, Qiang

2018-03-15

Trichloroethylene (TCE) degradation in sand columns has been investigated to evaluate the potential of chelates-enhanced Fenton-like reaction with magnetite as iron source for in situ treatment of TCE-contaminated groundwater. The results showed that successful degradation of TCE in sand columns was obtained by nitrilotriacetic acid (NTA)-assisted Fenton-like reaction of magnetite. Addition of ethylenediaminedisuccinic acid (EDDS) resulted in an inhibitory effect on TCE degradation in sand columns. Similar to EDDS, addition of ethylenediaminetetraacetic acid (EDTA) also led to an inhibition of TCE degradation in sand column with small content of magnetite (0.5 w.t.%), but enhanced TCE degradation in sand column with high content of magnetite (7.0 w.t.%). Additionally, the presence of NTA, EDDS and EDTA greatly decreased H 2 O 2 uptake in sand columns due to the competition between chelates and H 2 O 2 for surface sites on magnetite (and sand). Furthermore, the presented results show that magnetite in sand columns remained stable in a long period operation of 230 days without significant loss of performance in terms of TCE degradation and H 2 O 2 uptake. Moreover, it was found that TCE was degraded mainly to formic acid and chloride ion, and the formation of chlorinated organic intermediates was minimal by this process. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of substrate degradation, metabolite formation and microbial community responses in sand bioreactors treating winery wastewater: a comparative study.

Science.gov (United States)

Welz, P J; Palmer, Z; Isaacs, S; Kirby, B; le Roes-Hill, M

2014-12-01

There is a global need for the implementation of more cost-effective green technologies for the treatment of effluent from wineries. However, systems reliant on microbial biodegradation may be adversely affected by the highly seasonal character of cellar waste. In this study, the biodegradation of two different formulations of winery effluent in sand bioreactors was compared. The degradation of organic substrates and formation of metabolites was monitored by physicochemical analyses of pore water and final effluent samples. Changes in the bacterial community structures were detected using molecular fingerprinting. In wastewater with an overall COD of 2027 mg/L, a formulation with a high concentration of acetate (800 mg COD/L) was more recalcitrant to degradation than a formulation with a high concentration of glucose (800 mg COD/L). Ethanol, glucose and phenolics were degraded preferentially in the deeper layers of the sand bioreactors (average Eh 25 mV) than in the superficial layers (average Eh 102 mV). The redox status also played a pivotal role on the bacterial community composition. The study yielded valuable insight that can be utilized in the design (configuration and operation) of full scale sand bioreactors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation by PIXE external beam-of the leaching efficiency for a thermo stated column for the sand treatment

International Nuclear Information System (INIS)

Aspiazu, J.; Vite, J.; Vivero, R.; Mendez, B.

1995-01-01

The purpose of this paper was to measure the leaching efficiency for a thermo stated column designed to extract metals in muds originated by foundry process. The results obtained were useful to contemplate different alternatives helping to solve the problem of stocking enormous volumes of polluted sand produced by industries. Samples of residual sands and muds (treated sands) coming from an engine factory and from a thermo stated column respectively, were irradiated using an external beam of 3.55 MeV energy protons. From the quantitative analysis PIXE (Proton Induced X-ray Emission), it was possible to establish the level of pollution in sands due to the foundry processes and to evaluate the leaching efficiency of the output liquid phase from the thermo stated column. For polluted sands, certain cases were observed for which the efficiency was not enough to decrease the level of pollution in, e.g., Cu, Zn, Br and Pb. (Author)

Evaluation by PIXE external beam of the leaching efficiency for a thermo stated column for the sand treatment

International Nuclear Information System (INIS)

Aspiazu, J.; Vite, J.; Vivero, R.; Mendez, B.

1995-01-01

The purpose of this paper was to measure the leaching efficiency for a thermo stated column designed to extract metals in muds originated by foundry processes. The results obtained were useful to contemplate different alternatives helping to solve the problem of stocking enormous volumes of polluted sand produced by industries. Samples of residual sands and muds (treated sands) coming from an engine factory and from a thermo stated column respectively, were irradiated using an external beam of 3.55 MeV energy protons. From the quantitative analysis PIXE (Proton Induced X-ray Emission), it was possible to establish the level of pollution in sands due to the foundry processes and to evaluate the leaching efficiency of the output liquid phase from the thermo stated column. For polluted sands, certain cases were observed for which the efficiency was not enough to decrease the level of pollution in e.g., Cu, Zn, Br y Pb. (Author)

Evaluation of Aguas Dulces Black sands reserves, Rocha, Uruguay

International Nuclear Information System (INIS)

Ferrando, L.; Bossi, J.; Maldonado, S.; Schipilov; Campal, N.

2003-01-01

Black sands data in Aguas Dulces (Rocha) studied by ANCAP during 60 were reanalyzed with geological criterion in order to redefine the prefactibility of economic explotation with the present infrastructure and world market conditions.The sand deposits is limited between a high slope palaeocost and the ocean, with medium depth of 10m and 2% of useful minerals:ilmenite, rutile, monazite and zircon.Mineral reserves expressed in thousands of tons are of 3 kinds:proved (3.600), probable (5.500) and possible (16.000=.Demonstrated reserves (proved + probable) allow to estimate a value of U$S 650 million, taking in account year 2000 prices. A factory to process about 7 millions ton of raw sand needs an investment of U$S 13 million and will produce a sale of U$S 8 million per year

In situ recovery of oil from Utah tar sand: a summary of tar sand research at the Laramie Energy Technology Center

Energy Technology Data Exchange (ETDEWEB)

Marchant, L.C.; Westhoff, J.D.

1985-10-01

This report describes work done by the United States Department of Energy's Laramie Energy Technology Center from 1971 through 1982 to develop technology for future recovery of oil from US tar sands. Work was concentrated on major US tar sand deposits that are found in Utah. Major objectives of the program were as follows: determine the feasibility of in situ recovery methods applied to tar sand deposits; and establish a system for classifying tar sand deposits relative to those characteristics that would affect the design and operation of various in situ recovery processes. Contents of this report include: (1) characterization of Utah tar sand; (2) laboratory extraction studies relative to Utah tar sand in situ methods; (3) geological site evaluation; (4) environmental assessments and water availability; (5) reverse combustion field experiment, TS-1C; (6) a reverse combustion followed by forward combustion field experiment, TS-2C; (7) tar sand permeability enhancement studies; (8) two-well steam injection experiment; (9) in situ steam-flood experiment, TS-1S; (10) design of a tar sand field experiment for air-stream co-injection, TS-4; (11) wastewater treatment and oil analyses; (12) economic evaluation of an in situ tar sand recovery process; and (13) appendix I (extraction studies involving Utah tar sands, surface methods). 70 figs., 68 tabs.

Oil sands: Strategies for future development - An overview

International Nuclear Information System (INIS)

Yildirim, E.

1995-01-01

The Alberta Chamber of Resources developed a Task Force in 1993 to promote oil sands development, and to identify and publicize the social and economic benefits of oil sands operations. Formation, mission of the National Task Force, impediments and opportunities for development were summarized. Attributes of oil sands, benefits of their development, impediments to development, strategic development and potential growth scenarios were discussed. Cooperation between government and industry was deemed essential. Recommendations included development of a bitumen pipeline network, provision of incentives to encourage development, encouragement of risk and reward sharing between bitumen producers and up graders, and diversification of products and by-products. 7 figs., 12 refs

Sand transport, erosion and granular electrification

DEFF Research Database (Denmark)

Merrison, J.P.

2012-01-01

is expanding our current understanding and outline the areas of advancement needed in the future. Presentation is made of current models for wind driven detachment/entrainment and the transport rates of sand and dust, including the effects of contact induced grain electrification. This ubiquitous phenomenon...... can affect grain transport through the generation of intense electric fields and processes of electrostatic assembly. Importantly the transport of sand is characterized by saltation, which is known to be an active process for erosion and therefore a source for dust and sand formation. Using novel...... erosion simulation techniques the link between grain transport rates and erosion rates has been quantified. Furthermore this can be linked to production rates for dust and has been associated with chemical and mineral alteration through a process of mechanical activation of fractured surfaces. This work...

Oil sands tailings management project

Energy Technology Data Exchange (ETDEWEB)

Godwalt, C. [Alberta WaterSMART, Calgary, AB (Canada); Kotecha, P. [Suncor Energy Inc, Calgary, AB (Canada); Aumann, C. [Alberta Innovates - Technology Futures, Alberta Governement, AB (Canada)

2010-11-15

The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

Oil sands tailings management project

International Nuclear Information System (INIS)

Godwalt, C.; Kotecha, P.; Aumann, C.

2010-11-01

The Oil sands leadership initiative (OSLI) works with the Government of Alberta on the development of the oil sands industry, considering environmental, economical and social aspects. Water management was identified as one of most important areas to focus on. Alberta WaterSMART was requested to support the development and the management of projects resulting from the work done or underway in this field. The development of a regional water management solution stood out as the most interesting solution to obtain significant results. In the Athabasca Region, oil sands producers work independently on their water sourcing and disposal with particular attention to fresh water conservation and economics. The Athabasca River represents a source for mines and distant saline aquifers are the target of steam assisted gravity drainage (SAGD) operators. As part of a four-phase project aiming to study the environmental and economic footprint (EEF) benefit of alternatives for Athabasca oil sands production water supply and disposal, the purpose of the tailings water management project was to identify tailings treatment technologies that are ready to be implemented, and to design and evaluate solutions in order to improve regional oil sands production water sourcing and disposal. Alternatives were evaluated based on their total EEF, applying a lifecycle assessment methodology with a particular attention on the quantification of important performance indicators. 25 refs., 8 tabs., 40 figs.

Methane hydrate distribution from prolonged and repeated formation in natural and compacted sand samples: X-ray CT observations

Energy Technology Data Exchange (ETDEWEB)

Rees, E.V.L.; Kneafsey, T.J.; Seol, Y.

2010-07-01

To study physical properties of methane gas hydrate-bearing sediments, it is necessary to synthesize laboratory samples due to the limited availability of cores from natural deposits. X-ray computed tomography (CT) and other observations have shown gas hydrate to occur in a number of morphologies over a variety of sediment types. To aid in understanding formation and growth patterns of hydrate in sediments, methane hydrate was repeatedly formed in laboratory-packed sand samples and in a natural sediment core from the Mount Elbert Stratigraphic Test Well. CT scanning was performed during hydrate formation and decomposition steps, and periodically while the hydrate samples remained under stable conditions for up to 60 days. The investigation revealed the impact of water saturation on location and morphology of hydrate in both laboratory and natural sediments during repeated hydrate formations. Significant redistribution of hydrate and water in the samples was observed over both the short and long term.

44 CFR 65.11 - Evaluation of sand dunes in mapping coastal flood hazard areas.

Science.gov (United States)

2010-10-01

... mapping coastal flood hazard areas. 65.11 Section 65.11 Emergency Management and Assistance FEDERAL... Insurance Program IDENTIFICATION AND MAPPING OF SPECIAL HAZARD AREAS § 65.11 Evaluation of sand dunes in mapping coastal flood hazard areas. (a) General conditions. For purposes of the NFIP, FEMA will consider...

Reuse of waste cutting sand at Lawrence Livermore National Laboratory

International Nuclear Information System (INIS)

Mathews, S.; Wilson, K.

1998-01-01

Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchased by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in a concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved

Environmental Impacts of Sand Exploitation. Analysis of Sand Market

Directory of Open Access Journals (Sweden)

Marius Dan Gavriletea

2017-06-01

Full Text Available Sand is an indispensable natural resource for any society. Despite society’s increasing dependence on sand, there are major challenges that this industry needs to deal with: limited sand resources, illegal mining, and environmental impact of sand mining. The purpose of this paper is twofold: to present an overview of the sand market, highlighting the main trends and actors for production, export and import, and to review the main environmental impacts associated with sand exploitation process. Based on these findings, we recommend different measures to be followed to reduce negative impacts. Sand mining should be done in a way that limits environmental damage during exploitation and restores the land after mining operations are completed.

Design of Screens for Sand Control of Wells

Directory of Open Access Journals (Sweden)

Ján Pinka

2006-04-01

Full Text Available Drilling, completion, production, and reservoir engineers, supervisors, foremen, superintendents, service company personnel, technologists and anyone involved with recommending, selecting, designing or on-site performance of well completions or workovers where sand production is, or may become, a serious problem will benefit from this course. Less sand influx can be expected in a horizontal well than in a vertical well. If horizontal holes in weak formation sands can be successfully gravel packed, the result could be significantly higher well productivity than with a liner, screen or pre-packed screen alone. The article covers innovative screens for sand control used in oil and gas industry from the world leaders in total completion. The type of screen (wire wrapped, reinforced, pre-packed, ect. should also be chosen with due consideration to running-in condition (curve radius, compression when the screens are pushed along the drain hole, etc..

Geomorphology and drift potential of major aeolian sand deposits in Egypt

Science.gov (United States)

Hereher, Mohamed E.

2018-03-01

Aeolian sand deposits cover a significant area of the Egyptian deserts. They are mostly found in the Western Desert and Northern Sinai. In order to understand the distribution, pattern and forms of sand dunes in these dune fields it is crucial to analyze the wind regimes throughout the sandy deserts of the country. Therefore, a set of wind data acquired from twelve meteorological stations were processed in order to determine the drift potential (DP), the resultant drift potential (RDP) and the resultant drift direction (RDD) of sand in each dune field. The study showed that the significant aeolian sand deposits occur in low-energy wind environments with the dominance of linear and transverse dunes. Regions of high-energy wind environments occur in the south of the country and exhibit evidence of deflation rather than accumulation with the occurrence of migratory crescentic dunes. Analysis of the sand drift potentials and their directions help us to interpret the formation of major sand seas in Egypt. The pattern of sand drift potential/direction suggests that the sands in these seas might be inherited from exogenous sources.

Effectiveness of SCADA Systems in Control of Green Sands Properties

Directory of Open Access Journals (Sweden)

Ignaszak Z.

2016-03-01

Full Text Available The paper undertakes an important topic of evaluation of effectiveness of SCADA (Supervisory Control and Data Acquisition systems, used for monitoring and control of selected processing parameters of classic green sands used in foundry. Main focus was put on process studies of properties of so-called 1st generation molding sands in the respect of their preparation process. Possible methods of control of this processing are presented, with consideration of application of fresh raw materials, return sand (regenerate and water. The studies conducted in one of European foundries were aimed at pointing out how much application of new, automated plant of sand processing incorporating the SCADA systems allows stabilizing results of measurement of selected sand parameters after its mixing. The studies concerned two comparative periods of time, before an implementation of the automated devices for green sands processing (ASMS - Automatic Sand Measurement System and MCM – Main Control Module and after the implementation. Results of measurement of selected sand properties after implementation of the ASMS were also evaluated and compared with testing studies conducted periodically in laboratory.

Improvement of composition of core sand and molding sand mixtures for power machine building castings

International Nuclear Information System (INIS)

Velikanov, G.F.; Primak, I.N.; Brechko, A.A.

1982-01-01

Considered is a problem of development and improvement of mixtures, as well as of antisticking coatings with the given parameters providing production of castings of the necessary quality. Requirements to properties of mixtures and antisticking coatings are formulated proceeding from the conditions of guaranteed production of qualitative steel castings with mass from 0.5 up to 20t and wall thickness from 60 up to 200 mm. Formation of film structure of binding compositions is studied, their marginal contact angle and surface tension are determined. In the result of work carried out on improvement of core sand and molding sand mixtures the labour productivity during the production of core and moldings has been increased in 20-25% in average, the quality has also been improved [ru

Assessment of recycled PET properties for application on oil wells as sand control agents; Avaliacao de propriedades de PET reciclado para aplicacao em pocos de petroleo como agente de contencao de areia

Energy Technology Data Exchange (ETDEWEB)

Pereira, Alexandre Zacarias Ignacio [PETROBRAS, Rio de Janeiro, RJ (Brazil); Delpech, Marcia Cerqueira [Universidade do Estado do Rio de Janeiro (IQ/UERJ), RJ (Brazil). Inst. de Quimica], e-mail: mcd@uerj.br

2008-07-01

The Sand Control is fundamental for oil production in unconsolidated sandstone formations. It consists of the installation of a filter made of stainless steel screens and grained materials (sand control agents) which are, normally, high density inorganic substances (sand, ceramic, bauxite). Shallow formations, near to the sea bed, are more sensitive and need different kinds of sand control agents with low density. The objective of this work was the evaluation of recycled poly(ethylene terephthalate), PET, as sand control agent for oil wells. Pack permeability and thermal stability tests results, after up to six months of exposure to sea water and crude oil, have indicated that the recycled PET kept the necessary characteristics for the proposed application. Also, it was observed that the PET grain pack did not presented significant property modifications in the exposure conditions, when compared to the non-exposed samples. (author)

An Investigation for Disposal of Drill Cuttings into Unconsolidated Sandstones and Clayey Sands

Energy Technology Data Exchange (ETDEWEB)

Mese, Ali; Dvorkin, Jack; Shillinglaw, John

2000-09-11

This project include experimental data and a set of models for relating elastic moduli/porosity/texture and static-to-dynamic moduli to strength and failure relationships for unconsolidated sands and clayey sands. The results of the project should provide the industry with a basis for wider use of oil base drilling fluids in water sensitive formations by implementing drill cutting injection into existing wells at abandoned formations and controlling fracture geometry to prevent ground water contamination.

Characteristics of SCC with Fly Ash and Manufactured Sand

Science.gov (United States)

Praveen Kumar, K.; Radhakrishna

2016-09-01

Self compacting concrete (SCC) of M40 grade was designed. The binder in SCC consists of OPC and fly ash in the ratio of 65:35. River sand was replaced by manufactured sand (M-sand) at replacement levels of 20,40,60,80 and 100%. An attempt was made to evaluate the workability and strength characteristics of self compacting concrete with river sand and manufactured sand as fine aggregates. For each replacement level, constant workability was maintained by varying the dosage of superplasticizer. T50 flow time, V Funnel time, V-funnel T5 time as well as compressive, split tensile and flexural strength of SCC were found at each replacement level of M-sand. They were compared to SCC with river sand. Results indicate favourable use of M-sand in preparation of Self Compacting Concrete.

Study on the Permeability Characteristics of Polyurethane Soil Stabilizer Reinforced Sand

Directory of Open Access Journals (Sweden)

Jin Liu

2017-01-01

Full Text Available A polymer material of polyurethane soil stabilizer (PSS is used to reinforce the sand. To understand the permeability characteristics of PSS reinforced sand, a series of reinforcement layer form test, single-hole permeability test, and porous permeability test of sand reinforced with PSS have been performed. Reinforcement mechanism is discussed with scanning electron microscope images. The results indicated that the permeability resistance of sand reinforced with polyurethane soil stabilizer is improved through the formation of reinforcement layer on the sand surface. The thickness and complete degree of the reinforcement layer increase with the increasing of curing time and PSS concentration. The water flow rate decreases with the increasing of curing time or PSS concentration. The permeability coefficient decreases with the increasing of curing time and PSS concentration and increases with the increasing of depth in specimen. PSS fills up the voids of sand and adsorbs on the surface of sand particle to reduce or block the flowing channels of water to improve the permeability resistance of sand. The results can be applied as the reference for chemical reinforcement sandy soil engineering, especially for surface protection of embankment, slope, and landfill.

Palynology of the middle jurassic lower graben sand formation of the U-1 well, Danish Central Trough

Energy Technology Data Exchange (ETDEWEB)

Hoelstad, T.

1986-01-01

Twenty-one sidewall core samples from the lower 56 metres of the Lower Graben Sand Formation in the U-1 well are described with respect to their kerogen content and microflora in order to gain a better understanding of the depositional environment and the age relations. Based on e.g. the inconsistent dinoflagellate cyst occurrences, marginal marine conditions are concluded. The dinoglagellate cyst Pareodinia prolongata, Acanthaulax senta, Scriniodinium crystallinum, Energlynia acollaris, Wanaea thysanota and Hystrichogonyaulax cladophora and the recovered playnomorph assemblage in general permit an age determination as follows: 21 m Collovian undifferentiated, 7.9 latest Middle Callovian - earliest Late Callovian, 6.1 m latest Late Callovian and 21 m latest Late Callovian. - earliest Early Oxfordian.

Sand transportation and reverse patterns over leeward face of sand dune

Science.gov (United States)

Jiang, Hong; Dun, Hongchao; Tong, Ding; Huang, Ning

2017-04-01

Sand saltation has complex interactions with turbulent flow and dune form. Most models of wind-blown sand consider ideal circumstances such as steady wind velocity and a flat surface, and the bulk of data on wind flow and sand transport over an individual dune has focused mostly on the influence of dune shape or inter-dune space on the wind flow, neglecting the effect of morphology on sand saltation, particularly airflow and sand transportation over the leeward slope. Wind flow structures over the leeward slope of sand dunes have a fundamental influence on the organization of sand dunes. In order to understand sand dune dynamics, lee face airflow and sediment transportation should be paid more attention. Previous field observations could not measure turbulent flow structure well because of the limited observation points and the influence of experiment structure on wind field. In addition, the reverse sand particles over leeward face could not be collected by sand trap in field. Numerous field observations could not measure turbulent flow structure because of the limited observation points and the influence of experimental structures on the wind field. In addition, the reverse transport of sand particles over leeward face could not be collected by sand traps in field. Therefore, this paper aims to investigate the turbulent flow structure and sand transport pattern over the leeward slope. A numerical model of sand saltation over slope terrain is constructed, which also considers the coupling effects between air flow and sand particles. The large eddy simulation method is used to model turbulent flow. Sand transport is simulated by tracking the trajectory of each sand particle. The results show that terrain significantly alters the turbulent air flow structure and wind-blown sand movement, especially over the leeward slope. Here, mass flux increases initially and then decreases with height in the reversed flow region in the direction of wind flow, and the mass flux

Modifying Formative Evaluation Techniques For Distance Education Class Evaluation

Directory of Open Access Journals (Sweden)

Scott L. WALKER

2005-10-01

Full Text Available Modifying Formative Evaluation Techniques For Distance Education Class Evaluation Assistant Professor Scott L. WALKERDepartment of GeographyTexas State UniversitySan Marcos, USA ABSTRACTPost-secondary classes are usually followed by mandatory summative evaluations, yet changes in teaching and course structure cannot be made with summative evaluations. Formative evaluations in online education can result in candid responses from students if a third-party facilitator is involved in the process. This paper presents a method for conducting formative evaluation in an online class by utilizing the assistance of a colleague. Results of one such evaluation are presented, as are its advantages and disadvantages.

Water management challenges and perspective for surface oil sands operations in North Eastern Alberta

International Nuclear Information System (INIS)

MacKinnon, M.

2009-01-01

Oil sands waters has many sources, such as raw water inputs (import water and hydrologic waters); oil sands ore water such as formation water; and oil sands process-affected water (OSPW) such as produced water and released water from tailings. This presentation demonstrated the importance of water to oil sands operations and indicated how oil sands processing affects water quality. Water imports to meet oil sands needs is a topic of particular interest. Other topics that were presented included water properties changing during oil sands operations; tailings management and the effects on water quality; oil sands tailings and water management and the impact on water quality of the region; how oil sands processing affected water quality; and current tailings approach and proposed new tailings methods and the effects on water composition. Post extraction changes in OSPW and the potential impacts of engineered tailings were also discussed. It was concluded that water treatment options must meet water management objectives. figs.

Evaluation of beach grooming techniques on Escherichia coli density in foreshore sand at North Beach, Racine, WI

Science.gov (United States)

Kinzelman, Julie L.; Whitman, Richard L.; Byappanahalli, Muruleedhara N.; Jackson, Emma; Bagley, Robert C.

2003-01-01

Elevated levels of Escherichia coli(E. coli) in bathing waters at North Beach, a popular recreational site in Racine, Wisconsin, have been a persistent problem often resulting in the issuance of poor water quality advisories. Moreover, waterfowl (mostly Larus delawarensis and L. argentatus) in nearshore and offshore areas are common and may serve as non-point sources for bacterial contamination of recreational waters. Current beach management practice involves daily mechanical grooming of the nearshore sand for aesthetics and removal of hazardous debris. However, this practice has not been evaluated in terms of its effects on E. coli loading to beach sand and potential introduction to contiguous swimming water. In this study, we tested E. coli responses to three treatments: mechanical groomer, daily and twice weekly hand raking, and a control (no raking/grooming). A randomized block design consisted of replicated treatments and one control (10 each), for a total of 40 blocks sampled daily for 10 days. Foreshore sand samples were collected by hand coring to an average depth of 10 cm. Median E. colirecovered were 73 (mechanically groomed), 27 (hand-raked daily), 32 (hand-raked twice weekly), and 22 (control) colony-forming units (CFU) per gram dry weight sand. E. colicounts in sand that was groomed were significantly higher than hand rakings and control (p grooming efficacy and the importance of understanding non-point sources of bacterial contamination.

The provenance of Taklamakan desert sand

Science.gov (United States)

Rittner, Martin; Vermeesch, Pieter; Carter, Andrew; Bird, Anna; Stevens, Thomas; Garzanti, Eduardo; Andò, Sergio; Vezzoli, Giovanni; Dutt, Ripul; Xu, Zhiwei; Lu, Huayu

2016-03-01

Sand migration in the vast Taklamakan desert within the Tarim Basin (Xinjiang Uyghur Autonomous region, PR China) is governed by two competing transport agents: wind and water, which work in diametrically opposed directions. Net aeolian transport is from northeast to south, while fluvial transport occurs from the south to the north and then west to east at the northern rim, due to a gradual northward slope of the underlying topography. We here present the first comprehensive provenance study of Taklamakan desert sand with the aim to characterise the interplay of these two transport mechanisms and their roles in the formation of the sand sea, and to consider the potential of the Tarim Basin as a contributing source to the Chinese Loess Plateau (CLP). Our dataset comprises 39 aeolian and fluvial samples, which were characterised by detrital-zircon U-Pb geochronology, heavy-mineral, and bulk-petrography analyses. Although the inter-sample differences of all three datasets are subtle, a multivariate statistical analysis using multidimensional scaling (MDS) clearly shows that Tarim desert sand is most similar in composition to rivers draining the Kunlun Shan (south) and the Pamirs (west), and is distinctly different from sediment sources in the Tian Shan (north). A small set of samples from the Junggar Basin (north of the Tian Shan) yields different detrital compositions and age spectra than anywhere in the Tarim Basin, indicating that aeolian sediment exchange between the two basins is minimal. Although river transport dominates delivery of sand into the Tarim Basin, wind remobilises and reworks the sediment in the central sand sea. Characteristic signatures of main rivers can be traced from entrance into the basin to the terminus of the Tarim River, and those crossing the desert from the south to north can seasonally bypass sediment through the sand sea. Smaller ephemeral rivers from the Kunlun Shan end in the desert and discharge their sediment there. Both river run

Geotechnical properties of oil-contaminated Kuwaiti sand

Energy Technology Data Exchange (ETDEWEB)

Al-Sanad, H.A.; Eid, W.K.; Ismael, N.F. [Kuwait Univ., Safat (Kuwait). Dept. of Civil Engineering

1995-05-01

Large quantities of oil-contaminated sands resulted from exploded oil wells, burning oil fires, the destruction of oil storage tanks, and the formation of oil lakes in Kuwait at the end of the Gulf War. An extensive laboratory testing program was carried out to determine the geotechnical characteristics of this material. Testing included basic properties, compaction and permeability tests, and triaxial and consolidation tests on clean and contaminated sand at the same relative density. Contaminated specimens were prepared by mixing the sand with oil in the amount of 6% by weight or less to match field conditions. The influence of the type of oil, and relative density was also investigated by direct shear tests. The results indicated a small reduction in strength and permeability and an increase in compressibility due to contamination. The preferred method of disposal of this material is to use it as a stabilizing material for other projects such as road construction.

Geotechnical properties of oil-contaminated Kuwaiti sand

International Nuclear Information System (INIS)

Al-Sanad, H.A.; Eid, W.K.; Ismael, N.F.

1995-01-01

Large quantities of oil-contaminated sands resulted from exploded oil wells, burning oil fires, the destruction of oil storage tanks, and the formation of oil lakes in Kuwait at the end of the Gulf War. An extensive laboratory testing program was carried out to determine the geotechnical characteristics of this material. Testing included basic properties, compaction and permeability tests, and triaxial and consolidation tests on clean and contaminated sand at the same relative density. Contaminated specimens were prepared by mixing the sand with oil in the amount of 6% by weight or less to match field conditions. The influence of the type of oil, and relative density was also investigated by direct shear tests. The results indicated a small reduction in strength and permeability and an increase in compressibility due to contamination. The preferred method of disposal of this material is to use it as a stabilizing material for other projects such as road construction

Geophysics comes of age in oil sands development

Energy Technology Data Exchange (ETDEWEB)

Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

2008-07-01

This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

Petrology of dune sand derived from basalt on the Ka'u Desert, Hawaii

Science.gov (United States)

Gooding, J. L.

1982-01-01

Dune sand from the Ka'u Desert, southwest flank of Kilauea volcano, Hawaii, is moderately well-sorted (median = 1.60 Phi, deviation = 0.60, skewness = 0.25, kurtosis = 0.68) and composed mostly of frosted subangular particles of basalt glass ('unfractionated' olivine-normative tholeitte), olivine, lithic fragments (subophitic and intersertal basalts; magnetite-ilmenite-rich basalts), reticular basalt glass, magnetite, ilmenite, and plagioclase, in approximately that order of abundance. Quantitative lithological comparison of the dune sand with sand-sized ash from the Keanakakoi Formation supports suggestions that the dune sand was derived largely from Keanakakoi ash. The dune sand is too well sorted to have been emplaced in its present form by base-surge but could have evolved by post-eruption reworking of the ash.

Mechanical and toxicological evaluation of concrete artifacts containing waste foundry sand.

Science.gov (United States)

Mastella, Miguel Angelo; Gislon, Edivelton Soratto; Pelisser, Fernando; Ricken, Cláudio; da Silva, Luciano; Angioletto, Elídio; Montedo, Oscar Rubem Klegues

2014-08-01

The creation of metal parts via casting uses molds that are generally made from sand and phenolic resin. The waste generated after the casting process is called waste foundry sand (WFS). Depending on the mold composition and the casting process, WFS can contain substances that prevent its direct emission to the environment. In Brazil, this waste is classified according to the Standard ABNT NBR 10004:2004 as a waste Class II (Non-Inert). The recycling of this waste is limited because its characteristics change significantly after use. Although the use (or reuse) of this byproduct in civil construction is a technically feasible alternative, its effects must be evaluated, especially from mechanical and environmental points of view. Thus, the objective of this study is to investigate the effect of the use of WFS in the manufacture of cement artifacts, such as masonry blocks for walls, structural masonry blocks, and paving blocks. Blocks containing different concentrations of WFS (up to 75% by weight) were produced and evaluated using compressive strength tests (35 MPa at 28 days) and toxicity tests on Daphnia magna, Allium cepa (onion root), and Eisenia foetida (earthworm). The results showed that there was not a considerable reduction in the compressive strength, with values of 35 ± 2 MPa at 28 days. The toxicity study with the material obtained from leaching did not significantly interfere with the development of D. magna and E. foetida, but the growth of the A. cepa species was reduced. The study showed that the use of this waste in the production of concrete blocks is feasible from both mechanical and environmental points of view. Copyright © 2014 Elsevier Ltd. All rights reserved.

Criticality design evaluation of the White Sands reactor building storage vault

International Nuclear Information System (INIS)

Philbin, J.S.; Nelson, W.E.

1979-03-01

This report describes the conceptual design and criticality evaluation of a storage vault for components of the fast pulse reactor at White Sands Missile Range. Criticality calculations were performed with the KENO-IV Monte Carlo code for various storage configurations in order to investigate the coupling between the portable reactor and storage arrays of spare reactor rings or other fissile components of similar mass. Abnormal conditions corresponding to pseudo--random arrays of the fuel components, as well as a number of flooded configurations, were also evaluated to assess criticality potential for highly unlikely situations. In a normal, dry configuration, the neutron self-multiplication factor, k/sub eff/, of the fully loaded 3 x 8 planar array plus the reactor is less than 0.87. A completely flooded vault was found to produce self-multiplication factors in excess of 1.2

Developing new markets for oil sands products

International Nuclear Information System (INIS)

Crandall, G.

2004-01-01

This paper presents a review by Purvin and Gertz of western Canadian crude oil supply. This energy consulting firm provides advise to the energy sector. It suggests that oil sands production will surpass declining conventional production. Oil sands supply includes bitumen, synthetic crude oil (SCO), and diluent. It is forecasted that oil sands will increase from 42 per cent of western supply in 2002 to 78 per cent in 2015. The potential of Alberta's oil sands was discussed along with a recent study of refined products and petrochemicals from bitumen. Upgrading, refining and petrochemical case studies were presented. The author examined if a Canadian oil sands upgrading project with high capital costs can be competitive with competing projects in the United States and internationally. In addition to supply and demand issues, the presentation examined infrastructure capability and market potential in the United States. The economic potential and risks of preferred business cases compared to upgrading to SCO were also evaluated. 15 figs

Quality stabilisation of synthetic sand containing bentonite in process lines

OpenAIRE

A. Fedoryszyn

2010-01-01

Stabilisation of sand quality requires the monitoring and control of sand moisture contents and its other parameters at each stage of sandprocessing, i.e. during the preparation of return sand mix and rebonding processes. Stabilisation of sand quality necessitates the use of reliable control equipment and evaluation procedures. This study outlines the scope and results of research work aimed to improve the control equipment to enhance the performance of turbine mixers. The paper reviews the m...

Reclaimability of the spent sand mixture – sand with bentonite – sand with furfuryl resin

Directory of Open Access Journals (Sweden)

J. Dańko

2011-04-01

Full Text Available Introduction of new binding materials and new technologies of their hardening in casting moulds and cores production requires theapplication of reclamation methods adequate to their properties as well as special devices realizing tasks. The spent sands circulationsystem containing the same kind of moulding and core sands is optimal from the point of view of the expected reclamation results.However, in the face of a significant variability of applied technologies and related to them various reclamation methods, the need - of theobtained reclamation products assessment on the grounds of systematic criteria and uniform bases – arises, with a tendency of indicatingwhich criteria are the most important for the given sand system. The reclaimability results of the mixture of the spent moulding sand withGeko S bentonite and the spent core sand with the Kaltharz 404U resin hardened by acidic hardener 100 T3, are presented in the paper.Investigations were performed with regard to the estimation of an influence of core sands additions (10 –25% on the reclaimed materialquality. Dusts and clay content in the reclaim, its chemical reaction (pH and ignition loss were estimated. The verification of the reclaiminstrumental assessment was performed on the basis of the technological properties estimation of moulding sand with bentonite, where the reclaimed material was used as a matrix.

The search for a source rock for the giant Tar Sand triangle accumulation, southeastern Utah

Science.gov (United States)

Huntoon, J.E.; Hansley, P.L.; Naeser, N.D.

1999-01-01

A large proportion (about 36%) of the world's oil resource is contained in accumulations of heavy oil or tar. In these large deposits of degraded oil, the oil in place represents only a fraction of what was present at the time of accumulation. In many of these deposits, the source of the oil is unknown, and the oil is thought to have migrated over long distances to the reservoirs. The Tar Sand triangle in southeastern Utah contains the largest tar sand accumulation in the United States, with 6.3 billion bbl of heavy oil estimated to be in place. The deposit is thought to have originally contained 13-16 billion bbl prior to the biodegradation, water washing, and erosion that have taken place since the middle - late Tertiary. The source of the oil is unknown. The tar is primarily contained within the Lower Permian White Rim Sandstone, but extends into permeable parts of overlying and underlying beds. Oil is interpreted to have migrated into the White Rim sometime during the Tertiary when the formation was at a depth of approximately 3500 m. This conclusion is based on integration of fluid inclusion analysis, time-temperature reconstruction, and apatite fission-track modeling for the White Rim Sandstone. Homogenization temperatures cluster around 85-90??C for primary fluid inclusions in authigenic, nonferroan dolomite in the White Rim. The fluid inclusions are associated with fluorescent oil-bearing inclusions, indicating that dolomite precipitation was coeval with oil migration. Burial reconstruction suggests that the White Rim Sandstone reached its maximum burial depth from 60 to 24 Ma, and that maximum burial was followed by unroofing from 24 to 0 Ma. Time-temperature modeling indicates that the formation experienced temperatures of 85-90??C from about 35 to 40 Ma during maximum burial. Maximum formation temperatures of about 105-110??C were reached at about 24 Ma, just prior to unroofing. Thermal modeling is used to examine the history of potential source rocks

Depositional environment, sand provenance, and diagenesis of the Basal Salina Formation (lower Eocene), northwestern Peru

Science.gov (United States)

Marsaglia, K. M.; Carozzi, A. V.

The Basal Salina Formation is a lower Eocene transgressive sequence consisting of interbedded shales, siltstones, and conglomeratic sandstones. This formation occurs in the Talara basin of northwestern Peru and is one of a series of complexly faulted hydrocarbon-producing formations within this extensional forearc basin. These sediments were probably deposited in a fan-delta complex that developed along the ancestral Amotape Mountains during the early Eocene. Most of the sediment was derived from the low-grade metamorphic and plutonic rocks that comprise the Amotape Mountains, and their sedimentary cover. Detrital modes of these sandstones reflect the complex tectonic history of the area, rather than the overall forearc setting. Unlike most forearc sediments, these are highly quartzose, with only minor percentages of volcanic detritus. This sand is variably indurated and cemented by chlorite, quartz, calcite, and kaolinite. Clay-mineral matrix assemblages show gradational changes with depth, from primarily detrital kaolinite to diagenetic chlorite and mixed-layered illite/smectite. Basal Salina sandstones exhibit a paragenetic sequence that may be tied to early meteoric influx or late-stage influx of thermally driven brines associated with hydrocarbon migration. Much of the porosity is secondary, resulting from a first-stage dissolution of silicic constituents (volcanic lithic fragments, feldspar, and fibrous quartz) and a later dissolution of surrounding carbonate cement. Types of pores include skeletal grains, grain molds, elongate pores, and fracture porosity. Measured porosity values range up to 24% and coarser samples tend to be more porous. Permeability is enhanced by fractures and deterred by clay-mineral cements and alteration residues.

EVALUATION OF THE BENTONITE CONTENT IN SPENT FOUNDRY SANDS AS A FUNCTION OF HYDRAULIC CONDUCTIVITY COEFFICIENT

Directory of Open Access Journals (Sweden)

Schirlene Chegatti

2013-06-01

Full Text Available This study evaluates the relationship of the bentonite content and hydraulic conductivity coefficient (k of waste foundry sands in tests of hydraulic conductivity in a flexible wall permeameter. The test samples had concentrations of activated sodium bentonite and natural sodium bentonite between 4% and 15%. It was also analyzed chemically the liquid leachate (aluminum, barium, chromium, cadmium, lead, phenols, iron, fluoride, and manganese, following de standard tests of Standard Methods 3111 B e D for the determination of this components in liquid samples. The experiments were supplemented with cation exchange capacity analysis. The results indicate that the values of are is related to the content of bentonite in waste foundry sand and the percolation from this waste disposal.

Eastern Scheldt Sand, Baskarp Sand No. 15

DEFF Research Database (Denmark)

Andersen, A. T; Madsen, E. B.; Schaarup-Jensen, A. L.

The present data report contains data from 13 drained triaxial tests, performed on two different sand types in the Soil Mechanics Laboratory at Aalborg University in March, 1997. Two tests have been performed on Baskarp Sand No. 15, which has already ken extensively tested in the Soil Mechanics...... Laboratory. The remaining 11 triaxial tests have ben performed on Eastern Scheldt Sand, which is a material not yet investigated at the Soil Mechanics Laboratory. In the first pari of this data report, the characteristics of the two sand types in question will be presented. Next, a description...... will described. In this connection, the procedure for preparation of the soil specimens will be presented, and the actual performance of the tests will be briefly outlined. Finally, the procedure for processing of the measurements from the laboratory in order to obtain usable data will be described. The final...

Preliminary evaluation of the physical impacts of a nearshore sand extraction project

International Nuclear Information System (INIS)

Anctil, F.; Ouellet, Y.

1991-01-01

A review is presented of the potential physical impacts of a nearshore sand extraction project in the Gulf of St. Lawrence. In Canada, sand extraction is mainly limited to the Beaufort Sea area, where in 1982 alone 15 million tonnes of aggregate was dredged to satisfy the requirements of offshore petroleum exploration; but there is much experience in nearshore dredging in Europe. Criteria related to impacts, developed for conditions prevailing in the North Sea (England) and the Gulf of Gascogne (France) are adapted to meet the more moderate hydrodynamic impacts of an extraction project in the Gulf of St. Lawrence. Potential impacts of extraction projects include destruction of sand bars or dunes, direct erosion resulting from beach drawdown or sedimentation interference, and impacts on littoral drift due to modified wave refraction patterns. Three schemes for the sand extraction are considered, and from the results, a fourth scheme is elaborated in such a way as to limit the negative impacts to the minor category. 17 refs., 5 figs., 4 tabs

High Temperature Thermal Properties of Bentonite Foundry Sand

Directory of Open Access Journals (Sweden)

Krajewski P.K.

2015-06-01

Full Text Available The paper presents results of measuring thermal conductivity and heat capacity of bentonite foundry sand in temperature range ambient - 900­­°C. During the experiments a technical purity Cu plate was cast into the green-sand moulds. Basing on measurements of the mould temperature field during the solidification of the casting, the temperature relationships of the measured properties were evaluated. It was confirmed that water vaporization strongly influences thermal conductivity of the moulding sand in the first period of the mould heating by the poured casting.

Professional Development through Formative Evaluation

Science.gov (United States)

Nsibande, Rejoice; Garraway, James

2011-01-01

Formative evaluation and its associated methodology of reflection on practice are used extensively in academic staff development. In reflecting on formative evaluation processes in both more traditional and newer programmes conducted at a university of technology, a number of variables reported in the literature were observed to have influenced…

Pathogen removal using saturated sand colums supplemented with hydrochar

NARCIS (Netherlands)

Chung, J.W.

2015-01-01

This PhD study has evaluated hydrochars derived from biowastes as adsorbents for pathogen removal in water treatment. Pathogen removal experiments were conducted by carrying out breakthrough analysis using a simple sand filtration set-up. Glass columns packed by 10 cm sand bed supplemented with

Constitutive Soil Properties for Mason Sand and Kennedy Space Center

Science.gov (United States)

Thomas, Michael A.; Chitty, Daniel E.

2011-01-01

Accurate soil models are required for numerical simulations of land landings for the Orion Crew Exploration Vehicle (CEV). This report provides constitutive material models for two soil conditions at Kennedy Space Center (KSC) and four conditions of Mason Sand. The Mason Sand is the test sand for LaRC s drop tests and swing tests of the Orion. The soil models are based on mechanical and compressive behavior observed during geotechnical laboratory testing of remolded soil samples. The test specimens were reconstituted to measured in situ density and moisture content. Tests included: triaxial compression, hydrostatic compression, and uniaxial strain. A fit to the triaxial test results defines the strength envelope. Hydrostatic and uniaxial tests define the compressibility. The constitutive properties are presented in the format of LSDYNA Material Model 5: Soil and Foam. However, the laboratory test data provided can be used to construct other material models. The soil models are intended to be specific to the soil conditions they were tested at. The two KSC models represent two conditions at KSC: low density dry sand and high density in-situ moisture sand. The Mason Sand model was tested at four conditions which encompass measured conditions at LaRC s drop test site.

Modeling the morphodynamics of shoreface-connected sand ridges

NARCIS (Netherlands)

Vis-star, N.C.

2008-01-01

The focus of this thesis is on the morphodynamics of shoreface-connected sand ridges, which are large-scale bedforms observed on the inner shelf of coastal seas where storms occur frequently. The main aim was to explore which physical processes control the formation, long-term evolution and main

A comparative study of the adsorption of uranium on commercial and natural (Cypriot) sea sand samples

International Nuclear Information System (INIS)

Maria Efstathiou; Ioannis Pashalidis

2013-01-01

The adsorption of hexavalent uranium on two different types of sea sand [e.g. a local, Cypriot (N S S) and a commercially available marine sediment (C S S)] has been investigated as a function of pH, initial metal concentration, ionic strength and contact time under normal atmospheric conditions. Before carrying out the adsorption experiments, the sea sand samples have been characterized by XRD, XRF, N 2 -adsorption, acid/base titrations and FTIR spectroscopy. Sample characterization showed clearly that the two sea sand types differ significantly in their composition, particularly in their calcite and FeOOH content. According to experimental data obtained from acid/base titrations and adsorption batch experiments sea sand composition affects the acid/base and the adsorption properties of the adsorbents. The extraordinary high affinity of N S S for hexavalent uranium in the alkaline pH region can be attributed to the formation of mixed U(VI)-carbonato surface species on the FeOOH crystal phases present in N S S, which effectively compete the formation of U(VI)-carbonato complexes in solution. On the other hand, data obtained by adsorption experiments carried out in solution of different ionic strengths don't differ significantly from one another indicating the formation of inner-sphere complexes. Finally, the adsorption on sea sands is a relatively fast two-step process. (author)

Effect of substrate size on sympatric sand darter benthic habitat preferences

Science.gov (United States)

Thompson, Patricia A.; Welsh, Stuart A.; Rizzo, Austin A.; Smith, Dustin M.

2017-01-01

The western sand darter, Ammocrypta clara, and the eastern sand darter, A. pellucida, are sand-dwelling fishes that have undergone range-wide population declines, presumably owing to habitat loss. Habitat use studies have been conducted for the eastern sand darter, but literature on the western sand darter remains sparse. To evaluate substrate selection and preference, western and eastern sand darters were collected from the Elk River, West Virginia, one of the few remaining rivers where both species occur sympatrically. In the laboratory, individuals were given the choice to bury into five equally available and randomly positioned substrates ranging from fine sand to granule gravel (0.12–4.0 mm). The western sand darter selected for coarse and medium sand, while the eastern sand darter was more of a generalist selecting for fine, medium, and coarse sand. Substrate selection was significantly different (p = 0.02) between species in the same environment, where the western sand darter preferred coarser substrate more often compared to the eastern sand darter. Habitat degradation is often a limiting factor for many species of rare freshwater fish, and results from this study suggest that western and eastern sand darters may respond differently to variations in benthic substrate composition.

Evaluation of an Intergrated / Biocoagulant-sand filter Drum for ...

African Journals Online (AJOL)

User

2015-03-18

Mar 18, 2015 ... to adopt simple sand filtration for water treatment is exigent. ... Moringa oleifera, a vegetable plant found across Africa have been noted ... leachate samples from waste dumps within the city of Bamenda .... Total solids mg/dm3.

Guide to preparing SAND reports. Revised

Energy Technology Data Exchange (ETDEWEB)

Locke, T.K. [ed.

1996-04-01

This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

Submarine sand ridges and sand waves in the eastern part of the China Sea

Science.gov (United States)

Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

2016-04-01

Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

The use of light weight deflectometer for in situ evaluation of sand degree of compaction

Directory of Open Access Journals (Sweden)

Amr F. Elhakim

2014-12-01

Full Text Available The light weight deflectometer (LWD, also known as the light falling weight deflectometer, light drop weight tester, and dynamic plate load test, is a hand portable device that was developed in Germany to measure the soil in situ LWD dynamic modulus. Typically, this modulus is used to evaluate the subsoil degree of compaction. Thus it is suitable for compaction quality control of soil-surfaced roads, embankments and replacement fill. As a dynamic test, the device is suited, in particular, for coarse and mixed grained soils with a maximum grain size of 63 mm. The response of poorly graded calcareous and siliceous sands is the focus of this research. First, the index soil properties of the tested soils including grain size distribution; maximum and minimum void ratios and specific gravity were obtained. Petrographic analyses of the tested sands were also performed to determine their mineralogical composition. A 1-m3 chamber was built for performing the LWD testing in the laboratory. The study was performed for relative densities of 20%, 40%, 60% and 80% to represent the behavior of very loose, loose, medium dense and dense sands. The effect of the existence of a rigid boundary beneath the tested soil on test results was also investigated to determine the zone of influence of the light weight deflectometer.

Field evaluation of a new light trap for phlebotomine sand flies.

Science.gov (United States)

Gaglio, Gabriella; Napoli, Ettore; Falsone, Luigi; Giannetto, Salvatore; Brianti, Emanuele

2017-10-01

Light traps are one of the most common attractive method for the collection of nocturnal insects. Although light traps are generally referred to as "CDC light traps", different models, equipped with incandescent or UV lamps, have been developed. A new light trap, named Laika trap 3.0, equipped with LED lamps and featured with a light and handy design, has been recently proposed into the market. In this study we tested and compared the capture performances of this new trap with those of a classical light trap model under field conditions. From May to November 2013, a Laika trap and a classical light trap were placed biweekly in an area endemic for sand flies. A total of 256 sand fly specimens, belonging to 3 species (Sergentomyia minuta, Phlebotomus perniciosus, Phlebotomus neglectus) were collected during the study period. The Laika trap captured 126 phlebotomine sand flies: P. perniciosus (n=38); S. minuta (n=88), a similar number of specimens (130) and the same species were captured by classical light trap which collected also 3 specimens of P. neglectus. No significant differences in the capture efficiency at each day of trapping, neither in the number of species or in the sex of sand flies were observed. According to results of this study, the Laika trap may be a valid alternative to classical light trap models especially when handy design and low power consumption are key factors in field studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Right timing in formative program evaluation.

Science.gov (United States)

Hall, Jori; Freeman, Melissa; Roulston, Kathy

2014-08-01

Since many educational researchers and program developers have limited knowledge of formative evaluation, formative data may be underutilized during the development and implementation of an educational program. The purpose of this article is to explain how participatory, responsive, educative, and qualitative approaches to formative evaluation can facilitate a partnership between evaluators and educational researchers and program managers to generate data useful to inform program implementation and improvement. This partnership is critical, we argue, because it enables an awareness of when to take appropriate action to ensure successful educational programs or "kairos". To illustrate, we use examples from our own evaluation work to highlight how formative evaluation may facilitate opportune moments to (1) define the substance and purpose of a program, (2) develop understanding and awareness of the cultural interpretations of program participants, and (3) show the relevance of stakeholder experiences to program goals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Survival and replication of Mycoplasma species in recycled bedding sand and association with mastitis on dairy farms in Utah.

Science.gov (United States)

Justice-Allen, A; Trujillo, J; Corbett, R; Harding, R; Goodell, G; Wilson, D

2010-01-01

Mycoplasma spp., usually Mycoplasma bovis, are important bovine pathogens that can cause mastitis, metritis, pneumonia, and arthritis. The currently documented routes of transmission of Mycoplasma spp. are through contaminated milking equipment and by direct animal contact. The existence of environmental sources for Mycoplasma spp. and their role in transmission and clinical disease is poorly characterized. Mycoplasma spp. (confirmed as M. bovis in 2 of 4 samples tested using PCR) was found in recycled bedding sand originating from a dairy experiencing an outbreak of clinical mycoplasma mastitis. Mycoplasma spp. were subsequently found in bedding sand from 2 other dairies whose bulk-tank milk was mycoplasma-positive. The association between the occurrence of Mycoplasma spp. in recycled bedding sand and mycoplasma mastitis in cows was further investigated using a pile of recycled sand from dairy 1. Study objectives included the determination of factors associated with the concentration of Mycoplasma spp. in recycled bedding sand and the duration of survival of mycoplasmas in the sand. We also evaluated the efficacy of 2 disinfectants at 2 different concentrations each for the elimination of Mycoplasma spp. from contaminated sand. Mycoplasma spp. survived in the sand pile for 8 mo. The concentration of Mycoplasma spp. within the sand pile was directly related to temperature and precipitation. It was also positively associated with the growth of gram-negative microorganisms, suggesting the possibility of the formation of a biofilm. Ideal temperatures for replication of Mycoplasma spp. occurred between 15 and 20 degrees C. Moisture in the sand and movement of the sand pile also appeared to play a role in replication of mycoplasmas. We found that 0.5% sodium hypochlorite or 2% chlorhexidine were efficacious in eliminating Mycoplasma spp. from contaminated bedding sand. Recycled bedding sand could be an environmental source of Mycoplasma spp., including M. bovis

Recent advances in research on the aeolian geomorphology of China's Kumtagh Sand Sea

Science.gov (United States)

Dong, Z.; Lv, P.

2014-02-01

The Kumtagh Sand Sea in the hyper-arid region of northwestern China remained largely unexplored until the last decade. It deserves study due to its significance in understanding the evolution of the arid environments in northwestern China, and even central Asia. Aeolian geomorphology in the sand sea has received unprecedented study in the last decade. Encouraging advances have been made in types of aeolian landforms, geological outlines, wind systems, the formation of aeolian landforms, several unique aeolian landforms, aeolian geomorphic regionalization, aeolian geomorphological heritages and tourism development, and aeolian sand hazards and their control. These advances expand our knowledge of aeolian geomorphology.

Relationships between sand and water quality at recreational beaches.

Science.gov (United States)

Phillips, Matthew C; Solo-Gabriele, Helena M; Piggot, Alan M; Klaus, James S; Zhang, Yifan

2011-12-15

Enterococci are used to assess the risk of negative human health impacts from recreational waters. Studies have shown sustained populations of enterococci within sediments of beaches but comprehensive surveys of multiple tidal zones on beaches in a regional area and their relationship to beach management decisions are limited. We sampled three tidal zones on eight South Florida beaches in Miami-Dade and Broward counties and found that enterococci were ubiquitous within South Florida beach sands although their levels varied greatly both among the beaches and between the supratidal, intertidal and subtidal zones. The supratidal sands consistently had significantly higher (p sand) than the other two zones. Levels of enterococci within the subtidal sand correlated with the average level of enterococci in the water (CFU/100mL) for the season during which samples were collected (r(s) = 0.73). The average sand enterococci content over all the zones on each beach correlated with the average water enterococci levels of the year prior to sand samplings (r(s) = 0.64) as well as the average water enterococci levels for the month after sand samplings (r(s) = 0.54). Results indicate a connection between levels of enterococci in beach water and sands throughout South Florida's beaches and suggest that the sands are one of the predominant reservoirs of enterococci impacting beach water quality. As a result, beaches with lower levels of enterococci in the sand had fewer exceedences relative to beaches with higher levels of sand enterococci. More research should focus on evaluating beach sand quality as a means to predict and regulate marine recreational water quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fontainebleau Sand

DEFF Research Database (Denmark)

Leth, Caspar Thrane

2006-01-01

The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand.......The report is a summary of results from laboratory tests in the geotechncial research group on Fontainebleau sand....

Vehicle non-exhaust emissions from the tyre-road interface - effect of stud properties, traction sanding and resuspension

Science.gov (United States)

Kupiainen, Kaarle J.; Pirjola, Liisa

2011-08-01

In Northern cities respirable street dust emission levels (PM 10) are especially high during spring. The spring time dust has been observed to cause health effects as well as discomfort among citizens. Major sources of the dust are the abrasion products from the pavement and traction sand aggregates that are formed due to the motion of the tyre. We studied the formation of respirable abrasion particles in the tyre-road interface due to tyre studs and traction sanding by a mobile laboratory vehicle Sniffer. The measurements were preformed on a test track, where the influence of varying stud weight and stud number per tyre on PM 10 emissions was studied. Studded tyres resulted in higher emission levels than studless tyres especially with speeds 50 km h -1 and higher; however, by using light weight studs, which approximately halves the weight of studs, or by reducing the number of studs per tyre to half, the emission levels decreased by approximately half. Additionally measurements were done with and without traction sand coverage on the pavement of a public road. After traction sanding the emission levels were not affected by tyre type but by formation and suspension of traction sand related dust from the road surface. The emissions after traction sanding decreased as a function of time as passing vehicles' motion shifted the sand grains away from the areas with most tyre-road contact.

Numerical Study of Piping Limits for Suction Installation of Offshore Skirted Foundations an Anchors in Layered Sand

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Thilsted, C. L.

2010-01-01

Skirted foundations and anchors have proved to be competitive solutions for various types of fixed offshore platforms, subsea systems and an attractive foundation alternative for offshore wind turbines. One main design challenge for skirted structures in sand is to penetrate the skirted deep enough...... to obtain the required capacity. In order to overcome the high penetration resistance in sand suction assisted penetration is needed. Suction installation may cause the formation of piping channels, which break down the hydraulic seal and prevent further installation. This paper presents a numerical study...... of failure limits during suction installation in respect to both homogenous and layered soil profile. A numerical flow analysis is performed to determine the hydraulic gradients developing in response to the suction applied, and the results are presented as simple closed form solutions useful for evaluation...

Basic study on the estimating the value of sand beach using amenities replace

OpenAIRE

Shin, B-S; Kim, K-H.

2013-01-01

The sand beach along the east coast of Korea offers beautiful scenery with high-quality sand for leisure, and is also famous for white-sand and pine-trees both of which are important scenic resources. Furthermore, the sand beach helps to maintain natural environment of the coastal area and has the function of a disaster prevention system against high waves. There are two major value evaluation methods, Travel Cost Method and Contingent Valuation Method, to assess the value of sand beach. Cont...

Dynamic simulation of cable shovel specific energy in oil sands excavation

Energy Technology Data Exchange (ETDEWEB)

Awuah-Offei, K. [Missouri-Rolla Univ., Rolla, MO (United States). School of Materials, Energy and Earth Resources; Frimpong, S. [Missouri-Rolla Univ., Rolla, MO (United States). Dept. of Mining Engineering, Mining and Nuclear Engineering; Askari-Nasab, H. [Alberta Univ., Edmonton, AB (Canada). School of Mining and Petroleum Engineering

2005-07-01

Oil sand excavation requires the use cable shovels which constitute one of the major costs in surface mining operations. Random occurrences of shales and limestones within the Athabasca oil sands formation result in varying shovel diggability and stress loading of the boom-crowd-dipper-teeth assembly which reduces digging efficiency. This inefficient use of cable shovels negatively affects the return on capital investment in these otherwise effective machines. In the Athabasca oil sands, varying stress loading has the potential to increase shovel downtime and increase maintenance costs. This paper presented a newly developed cable shovel simulator that uses shovel kinematics and dynamics, dynamic cutting resistance and payload models. It can model the specific energy needed to overcome the resistance to machine motion and material digging. The comprehensive model considers both machine motion and machine-formation interaction forces. It also provides a comprehensive theoretical assessment of shovel performance. The model is useful to mining engineers when examining both the machine operating parameters and material parameters that influence shovel performance. The study showed that bulk density is the most important material property influencing diggability. Operator preferences also influence the specific energy of excavation. 12 refs., 2 tabs., 6 figs.

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

Energy Technology Data Exchange (ETDEWEB)

Tikalsky, Paul J. [Pennsylvania State Univ., University Park, PA (United States); Bahia, Hussain U. [Univ. of Wisconsin, Madison, WI (United States); Deng, An [Pennsylvania State Univ., University Park, PA (United States); Snyder, Thomas [Univ. of Wisconsin, Madison, WI (United States)

2004-10-15

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

National Uranium Resource Evaluation: intermediate-grade uranium resource assessment project for part of the Maybell District, Sand Wash Basin, Colorado

International Nuclear Information System (INIS)

Goodknight, C.S.

1983-04-01

Intermediate-grade uranium resources in the Miocene Browns Park Formation were assessed for part of the Maybell district in the Sand Wash Basin, Colorado, as part of the National Uranium Resource Evaluation program conducted by Bendix Field Engineering Corporation for the US Department of Energy. Two sites, each 2 mi 2 (5 km 2 ) in size, in the district were selected to be assessed. Site selection was based on evaluation of geologic, geophysical, and geochemical data that were collected from a larger project area known to contain uranium enrichment. The assessment of the sites was accomplished primarily by drilling 19 holes through the Browns Park Formation and by using the geophysical and geochemical data from those holes and from a larger number of industry-drilled holes. Analytical results of samples from uranium prospects, mainly along faults in the sites, were also used for the assessment. Data from surface samples and from drill-hole samples and logs of the site south of Lay Creek indicate that no intermediate-grade uranium resources are present. However, similar data from the site north of Lay Creek verify that approximately 25 million lb (11.2 million kg) of intermediate-grade uranium resources may be present. This assessment assumes that an average uranium-enriched thickness of 10 ft (3 m) at a grade of 0.017% U 3 O 8 is present in at least two thirds of the northern site. Uranium enrichment in this site occurs mainly in the lower 150 ft (45 m) of the Browns Park Formation in fine- to medium-grained sandstone that contains abundant clay in its matrix. Facies variations within the Browns Park preclude correlation of individual beds or zones of uranium enrichment between closely spaced drill holes

Dynamic shear stiffness and damping ratio of marine calcareous and siliceous sands

Science.gov (United States)

Javdanian, Hamed; Jafarian, Yaser

2018-03-01

Shear stiffness and damping ratio of two marine calcareous and siliceous sands were evaluated through an experimental program. Resonant column and cyclic triaxial experiments were conducted to measure the dynamic properties of the sands in small and large shear strain amplitudes. The tests were conducted under various initial stress-density conditions. The influence of effective confining pressure on the dynamic properties of the sands was assessed and compared in a preceding paper. It was shown that the calcareous sand has higher shear stiffness and lower damping ratio in comparison to the siliceous sand. In this note, the results are presented in more details and the dynamic behavior curves of the studied sands are compared with some available models, mostly developed based on the laboratory data of siliceous sands. This comparative study reveals that the previous models predict the dynamic properties of the calcareous sand in less precision than those of the siliceous sand.

Large-eddy simulation of sand dune morphodynamics

Science.gov (United States)

Khosronejad, Ali; Sotiropoulos, Fotis; St. Anthony Falls Laboratory, University of Minnesota Team

2015-11-01

Sand dunes are natural features that form under complex interaction between turbulent flow and bed morphodynamics. We employ a fully-coupled 3D numerical model (Khosronejad and Sotiropoulos, 2014, Journal of Fluid Mechanics, 753:150-216) to perform high-resolution large-eddy simulations of turbulence and bed morphodynamics in a laboratory scale mobile-bed channel to investigate initiation, evolution and quasi-equilibrium of sand dunes (Venditti and Church, 2005, J. Geophysical Research, 110:F01009). We employ a curvilinear immersed boundary method along with convection-diffusion and bed-morphodynamics modules to simulate the suspended sediment and the bed-load transports respectively. The coupled simulation were carried out on a grid with more than 100 million grid nodes and simulated about 3 hours of physical time of dune evolution. The simulations provide the first complete description of sand dune formation and long-term evolution. The geometric characteristics of the simulated dunes are shown to be in excellent agreement with observed data obtained across a broad range of scales. This work was supported by NSF Grants EAR-0120914 (as part of the National Center for Earth-Surface Dynamics). Computational resources were provided by the University of Minnesota Supercomputing Institute.

Mice housed on coal dust-contaminated sand: A model to evaluate the impacts of coal mining on health

Energy Technology Data Exchange (ETDEWEB)

Caballero-Gallardo, Karina, E-mail: kcaballerog@unicartagena.edu.co; Olivero-Verbel, Jesus, E-mail: joliverov@unicartagena.edu.co

2016-03-01

Coal dust is the most important air pollutant in coal mining in regards to producing deleterious health effects. It permeates the surrounding environment threatening public health. The aim of this study was to evaluate the toxic effects associated with exposure to sand contaminated with coal dust particles below 38 μm in diameter, obtained from a mineral sample collected in the largest coal mine in South America, La Loma, Cesar, Colombia. Sterilized sand was spiked with coal dust to obtain concentrations ranging from zero to 4% coal dust. To model natural exposure, mice were housed for eight weeks in boxes containing this mixture as bedding after which, they were euthanized and blood and tissue samples were collected. Real time PCR analysis revealed an increase in Cyp1A1 mRNA for living on sand with coal dust concentrations greater than 2% compared to mice living on sand without coal dust. Unexpectedly, for mice on coal dust-polluted sand, Sod1, Scd1 and Nqo1 hepatic mRNA were downregulated. The Comet assay in peripheral blood cells and the micronucleus test in blood smears, showed a significant potential genotoxic effect only at the highest coal dust concentration. Histopathological analysis revealed vascular congestion and peribronchial inflammation in the lungs. A dose–response relationship for the presence of hepatic steatosis, vacuolization and nuclei enlargements was observed in the exposed animals. The data suggest living on a soil polluted with coal dust induces molecular, cellular and histopathological changes in mice. Accordingly, the proposed model can be used to identify deleterious effects of exposure to coal dust deposited in soils that may pose health risks for surrounding wildlife populations. - Highlights: • Mice were exposed to coal dust-contaminated sand. • mRNA Markers for PAH exposure, lipid metabolism and oxidative stress increased. • ALT activity in plasma increased at the highest exposure to coal dust. • Liver tissues of exposed

Gasification of oil sand coke: review

Energy Technology Data Exchange (ETDEWEB)

Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

1998-08-01

The production of synthetic crude from the tar sands in Western Canada has been steadily increasing. Most of the delayed coke produced by Suncor is combusted on site, whereas all fluid coke produced by Syncrude is stockpiled.The database on the chemical and physical properties of the oil sand coke, including the composition and fusion properties of the mineral matter, has been established. The reactivity of the coke was determined by oxygen chemisorption, fixed bed and fluid bed bench scale gasification and pilot plant gasification. The reactivity of the oil sand coke for gasification is rather low and comparable to high rank coals, such as anthracite. Slurrability tests revealed that a solid concentration in water, approaching 70 wt%, can be achieved. Gasification is the front runner among clean technologies for the conversion of carbonaceous solids to useful products. Several commercial gasifiers are available to cover the wide range of severity. Because of the low reactivity of oil sands coke, high severity conditions are required to achieve high gasification conversion. Such conditions can be attained in entrained bed gasifiers. Gasifiers employing both dry and slurry feeding systems are suitable. A high efficiency, low SO{sub x} and NO{sub x} emissions, as well as a low solid waste production are among the key advantages of the gasification technology compared with thecompeting technologies. Commercial gasification of oil sands coke is delayed because of the availability of natural gas on the site of the upgrading plants. Potential for the transportation of the oil sand coke to USA for electricity generation using the integrated gasification combined-cycle (IGCC) technology was evaluated. 27 refs., 17 figs., 9 tabs.

An evaluation of flora from coastal sand dunes of India: Rationale for conservation and management

Digital Repository Service at National Institute of Oceanography (India)

Rodrigues, R.S.; Mascarenhas, A.; Jagtap, T.G.

stream_size 37100 stream_content_type text/plain stream_name Ocean_Coast_Manage_54_181a.pdf.txt stream_source_info Ocean_Coast_Manage_54_181a.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 1... Author version: Ocean & Coastal Management, vol.54(2); 2011; 181-188 An evaluation of flora from coastal sand dunes of India: Rationale for conservation and management Rouchelle S. Rodrigues, Antonio Mascarenhas, Tanaji G. Jagtap * National...

Simulating cold production by a coupled reservoir-geomechanics model with sand erosion

Energy Technology Data Exchange (ETDEWEB)

Wang, Y.; Xue, S. [Petro-Geotech Inc., Calgary, AB (Canada)

2002-06-01

This paper presents a newly developed fully coupled reservoir-geomechanics model with sand erosion. Sand production occurs during aggressive production induced by the impact of viscous fluid flow and the in situ stress concentration near a wellbore, as well as by perforation tips in poorly consolidated formations. This compromises oil production, increases well completion costs, and reduces the life cycles of equipment down hole and on the surface. The proposed model can be used for sand production studies in conventional oil/gas reservoirs such as the North Sea as well as in heavy oil reservoirs such as in northwestern Canada. Instead of generating a high permeability network in reservoirs, the enhanced oil production is determined by the increase in the effective wellbore radius. This paper presents the general model. A detailed study on the capillary pressure and the impact of multiphase flow on sanding and erosion will be conducted at a later date. It appears that 2 phase flow can be important to elastoplasticity if no significant sand erosion has occurred. It was determined that high porosity is induced by erosion and capillary pressure. Two phase flow can be important when the built-up drag force carries sand-fluid slurry into the well. It is concluded that viscosity and flow velocity can help estimate the slurry transport, sand rate and enhanced oil production. 22 refs., 3 tabs., 11 figs.

Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

Energy Technology Data Exchange (ETDEWEB)

Pauul J. Tikalsky

2004-10-31

This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: (1) a statistically sound evaluation of the characterization of foundry sand, (2) a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and (3) the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at N{sub ini}, N{sub des}, and N{sub max}. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

Directory of Open Access Journals (Sweden)

Kwangheon Park

2015-09-01

Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.

Mice housed on coal dust-contaminated sand: A model to evaluate the impacts of coal mining on health.

Science.gov (United States)

Caballero-Gallardo, Karina; Olivero-Verbel, Jesus

2016-03-01

Coal dust is the most important air pollutant in coal mining in regards to producing deleterious health effects. It permeates the surrounding environment threatening public health. The aim of this study was to evaluate the toxic effects associated with exposure to sand contaminated with coal dust particles below 38 μm in diameter, obtained from a mineral sample collected in the largest coal mine in South America, La Loma, Cesar, Colombia. Sterilized sand was spiked with coal dust to obtain concentrations ranging from zero to 4% coal dust. To model natural exposure, mice were housed for eight weeks in boxes containing this mixture as bedding after which, they were euthanized and blood and tissue samples were collected. Real time PCR analysis revealed an increase in Cyp1A1 mRNA for living on sand with coal dust concentrations greater than 2% compared to mice living on sand without coal dust. Unexpectedly, for mice on coal dust-polluted sand, Sod1, Scd1 and Nqo1 hepatic mRNA were downregulated. The Comet assay in peripheral blood cells and the micronucleus test in blood smears, showed a significant potential genotoxic effect only at the highest coal dust concentration. Histopathological analysis revealed vascular congestion and peribronchial inflammation in the lungs. A dose-response relationship for the presence of hepatic steatosis, vacuolization and nuclei enlargements was observed in the exposed animals. The data suggest living on a soil polluted with coal dust induces molecular, cellular and histopathological changes in mice. Accordingly, the proposed model can be used to identify deleterious effects of exposure to coal dust deposited in soils that may pose health risks for surrounding wildlife populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of the effects of different sand particles that used in dental implant roughened for osseointegration.

Science.gov (United States)

Yurttutan, Mehmet Emre; Keskin, Ahmet

2018-03-20

Successful dental implant treatment is directly related to osseointegration. In achieving osseointegration, the surface property of the implant is of great importance. Sandblasting is the most commonly used basic method for modifying the surface. Many companies use different sand particles for surface roughening and claim their sand is the best. This leads clinicians to mix their minds in product selection. In this study, we tried to find the appropriate sand material by working objectively without praising any brand. We believe that the results of the study will help clinicians choose the right dental implant. In this study, machined-surfaced implants and implants sandblasted with Aluminum oxide (Al 2 O 3 ), Titanium dioxide (TiO 2 ) and Silicon dioxide (SiO 2 ) were compared via biomechanical testing. For the study, four 2 year-old sheep, weighing 45 kilograms (kg), were used. Eight implants (Al 2 O 3 , TiO 2 , and SiO 2 sandblasted implants and machined-surfaced implants), each with different surface characteristics, were inserted into the bilateral tibia of each sheep under general anesthesia. Results of the initial Resonance Frequency Analysis (RFA) were recorded just after implant insertion. The sheep were then randomly divided into two groups, each with 2 sheep, to undergo either a 1-month or a 3-month assessment. At the end of the designated evaluation period, RFA and removal torque tests were performed. Although there were no statistically significant differences between the groups, the implants sandblasted with Al 2 O 3 showed a higher Implant Stability Quotient (ISQ) and removal torque value at the end of the 1st and 3rd month. In short, the results of the study demonstrate that Aluminum oxide is superior to other sand particles.

New generation expandable sand screens

OpenAIRE

Syltøy, Christer

2014-01-01

Master's thesis in Petroleum engineering This thesis aims to give a general insight into sand control and various sorts of sand control measures and applications of sand control tools. Special focus will be given to expandable sand screens – a technology which came about in the late 1990’s through the use of flexible, expandable tubulars as base pipe in sand screens. More specifically Darcy’s Hydraulic Endurance Screens, a compliant sand screen system using hydraulic activation, and the fu...

Saltation of non-spherical sand particles.

Directory of Open Access Journals (Sweden)

Zhengshi Wang

Full Text Available Saltation is an important geological process and the primary source of atmospheric mineral dust aerosols. Unfortunately, no studies to date have been able to precisely reproduce the saltation process because of the simplified theoretical models used. For example, sand particles in most of the existing wind sand movement models are considered to be spherical, the effects of the sand shape on the structure of the wind sand flow are rarely studied, and the effect of mid-air collision is usually neglected. In fact, sand grains are rarely round in natural environments. In this paper, we first analyzed the drag coefficients, drag forces, and starting friction wind speeds of sand grains with different shapes in the saltation process, then established a sand saltation model that considers the coupling effect between wind and the sand grains, the effect of the mid-air collision of sand grains, and the effect of the sand grain shape. Based on this model, the saltation process and sand transport rate of non-spherical sand particles were simulated. The results show that the sand shape has a significant impact on the saltation process; for the same wind speed, the sand transport rates varied for different shapes of sand grains by as much as several-fold. Therefore, sand shape is one of the important factors affecting wind-sand movement.

SandBlaster: Reversing the Apple Sandbox

OpenAIRE

Deaconescu, Răzvan; Deshotels, Luke; Bucicoiu, Mihai; Enck, William; Davi, Lucas; Sadeghi, Ahmad-Reza

2016-01-01

In order to limit the damage of malware on Mac OS X and iOS, Apple uses sandboxing, a kernel-level security layer that provides tight constraints for system calls. Particularly used for Apple iOS, sandboxing prevents apps from executing potentially dangerous actions, by defining rules in a sandbox profile. Investigating Apple's built-in sandbox profiles is difficult as they are compiled and stored in binary format. We present SandBlaster, a software bundle that is able to reverse/decompile Ap...

Numerical Evaluation of Size Effect on the Stress-Strain Behaviour of Geotextile-Reinforced Sand

DEFF Research Database (Denmark)

Hosseinpour, I.; Mirmoradi, S.H.; Barari, Amin

2010-01-01

This paper studies the effect of sample size on the stress-strain behavior and strength characteristics of geotextile reinforced sand using the finite element numerical analysis. The effect of sample size was investigated by studying the effects of varying the number of geotextile layers, the con......This paper studies the effect of sample size on the stress-strain behavior and strength characteristics of geotextile reinforced sand using the finite element numerical analysis. The effect of sample size was investigated by studying the effects of varying the number of geotextile layers...... on the mechanical behavior of reinforced sand decreases with an increase in the sample size....

Effects of sea level rise on the formation and drowning of shoreface-connected sand ridges, a model study

Science.gov (United States)

Nnafie, A.; de Swart, H. E.; Calvete, D.; Garnier, R.

2014-06-01

Shoreface-connected sand ridges occur on many storm-dominated inner shelves. These rhythmic features have an along-shelf spacing of 2-10 km, a height of 1-12 m, they evolve on timescales of centuries and they migrate several meters per year. An idealized model is used to study the impact of sea level rise on the characteristics of the sand ridges during their initial and long-term evolution. Different scenarios (rates of sea level rise, geometry of inner shelf) are examined. Results show that with increasing sea level the height of sand ridges increases and their migration decreases until they eventually drown. This latter occurs when the near-bed wave orbital velocity drops below the critical velocity for erosion of sediment. In contrast, in the absence of sea level rise, the model simulates shoreface-connected sand ridges with constant heights and migration rates. Model results furthermore indicate that sand ridges do not form if the rate of sea level rise is too high, or if the initial depth of the inner shelf is too small. A larger transverse bottom slope enhances growth and height of sand ridges and they drown quicker. When shoreface retreat due to sea level rise is considered, new ridges form in the landward part of the inner shelf, while ridges on the antecedent part of the shelf become less active and ultimately drown. Only if sea level rise is accounted for, merging of ridges is reduced such that multiple ridges occur in the end state, thereby yielding a better agreement with observations. The physical mechanisms responsible for these findings are also explained.

Measurements of Dune Parameters on Titan Suggest Differences in Sand Availability

Science.gov (United States)

Stewart, Brigitte W.; Radebaugh, Jani

2014-11-01

The equatorial region of Saturn’s moon Titan has five large sand seas with dunes similar to large linear dunes on Earth. Cassini Radar SAR swaths have high enough resolution (300 m) to measure dune parameters such as width and spacing, which helps inform us about formation conditions and long-term evolution of the sand dunes. Previous measurements in locations scattered across Titan have revealed an average width of 1.3 km and spacing of 2.7 km, with variations by location. We have taken over 1200 new measurements of dune width and spacing in the T8 swath, a region on the leading hemisphere of Titan in the Belet Sand Sea, between -5 and -9 degrees latitude. We have also taken over 500 measurements in the T44 swath, located on the anti-Saturn hemisphere in the Shangri-La Sand Sea, between 0 and 20 degrees latitude. We correlated each group of 50 measurements with the average distance from the edge of the dune field to obtain an estimate of how position within a dune field affects dune parameters. We found that in general, the width and spacing of dunes decreases with distance from the edge of the dune field, consistent with similar measurements in sand seas on Earth. We suggest that this correlation is due to the lesser availability of sand at the edges of dune fields. These measurements and correlations could be helpful in determining differences in sand availability across different dune fields, and along the entire equatorial region of Titan.

Marine pollution: Let us not forget beach sand

OpenAIRE

Galgani, Francois; Ellerbrake, Katrin; Fries, Elke; Goreux, Chantal

2011-01-01

Background: Assessing the chemical or bacterial contamination in marine waters and sediments is a very common approach to evaluate marine pollution and associated risks. However, toxicity and organic pollution of beach sands have not yet been considered, except in adjacent waters. In the present study, the toxicity and the chemical contamination of natural beach sands collected 20 m from the shoreline at two sites located on the Mediterranean Sea (Marseille and La Marana, Corsica) were studie...

Heat-resistant agent used for control sand of steam huff and puff heavy oil well

Science.gov (United States)

Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

2018-01-01

Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

Indoor radon in houses built on gravel and sand deposits in southern Finland

Directory of Open Access Journals (Sweden)

Hutri, K.-L.

1993-06-01

Full Text Available Studies by the Finnish Centre for Radiation and Nuclear Safety (STUK have shown that, in Finland, indoor radon concentrations are almost twice as high in houses built on sand or gravel as in houses built on other soil types. The aim of this study was to assess the radon risk on eskers, ice-marginal formations, and other gravel and sand deposits on the basis of factors that can be determined from geological maps. Altogether, 514 houses built on gravel and sand deposits were selected for the study from the indoor radon database of STUK. Several geological parameters were determined. Empirical statistical models were used to assess the significance of factors affecting indoor radon in glaciofluvial deposits and the sand-dominant littoral deposits occurring in association with them. A relationship was found between increased indoor radon concentrations and the location of a house on a steep-sided esker, in the southeastern rapakivi granite area and on the upper slope or top of an esker. The steepness of the slope also increased the radon concentration in houses on steep-sided eskers. The effect of the topographic features is due to subterranean air-flows. As estimated from the very sparse till sampling, the elevated uranium concentration increased the indoor radon concentration only in houses built on littoral deposits around eskers and ice-marginal formations.

Liquefaction resistance of calcareous sands

International Nuclear Information System (INIS)

Sandoval Vallejo, Eimar

2012-01-01

Calcareous sands are unique in terms of their origin, mineralogy, shape, fragility and intra particle porosity. This article presents results from an experimental program carried out to study the liquefaction resistance of a calcareous sand retrieved from Cabo Rojo at Puerto Rico. The experimental program included mineralogical characterization, index properties, and undrained cyclic triaxial tests on isotropically consolidated reconstituted samples. Due to the large variation in the calcareous sand properties, results are compared with previous researches carried out on other calcareous sands around the world. Results showed a wide range in the liquefaction resistance of the studied calcareous sands. Cabo Rojo sand experienced greater liquefaction resistance than most of the calcareous sands used for comparison. Important differences in the excess pore pressure generation characteristics were also found.

Evaluating evaluation as a communication process. What role for formative evaluation in ICT-based knowledge acquisition?

Directory of Open Access Journals (Sweden)

USEILLE Philippe

2005-10-01

Full Text Available This article examines how formative evaluation as a communication process contributes to knowledge acquisition in using ICT (Information and Communication Technologies. Previous studies, especially in the field of education and training, have shown that formative evaluation plays a crucial part in the learning process because it contributes to learning to learn. Through formative evaluation, the learner becomes aware of errors and can adjust learning strategies to the situation. In addition, formative evaluation provides the teaching side with significant and useful information. Consequently, ICT researches have developed a wide range of solutions for this specific purpose. It is however difficult to check the efficiency of these tools by considering the effects of ICT in the knowledge acquisition process. I suggest that formative evaluation includes also a communication system that has an effect on the learning process. This study tackles the issue by proposing an alternative approach to formative evaluation that considers it as both a learning and a communication process. The study is based on SADT (Structure Analysis and Design Technique that provides a suitable description for the whole complex communication process. It allows a rigorous understanding and identification of the variables of evaluation as a communication process in order to take care of an ICT frame. Finally, this article outlines a multidisciplinary method to evaluate formative evaluation by focusing on the validity facets of the communication process. Keywords: formative evaluation, communication process, validity criteria, ICT training context.

Development and Application of a Life Cycle-Based Model to Evaluate Greenhouse Gas Emissions of Oil Sands Upgrading Technologies.

Science.gov (United States)

Pacheco, Diana M; Bergerson, Joule A; Alvarez-Majmutov, Anton; Chen, Jinwen; MacLean, Heather L

2016-12-20

A life cycle-based model, OSTUM (Oil Sands Technologies for Upgrading Model), which evaluates the energy intensity and greenhouse gas (GHG) emissions of current oil sands upgrading technologies, is developed. Upgrading converts oil sands bitumen into high quality synthetic crude oil (SCO), a refinery feedstock. OSTUM's novel attributes include the following: the breadth of technologies and upgrading operations options that can be analyzed, energy intensity and GHG emissions being estimated at the process unit level, it not being dependent on a proprietary process simulator, and use of publicly available data. OSTUM is applied to a hypothetical, but realistic, upgrading operation based on delayed coking, the most common upgrading technology, resulting in emissions of 328 kg CO 2 e/m 3 SCO. The primary contributor to upgrading emissions (45%) is the use of natural gas for hydrogen production through steam methane reforming, followed by the use of natural gas as fuel in the rest of the process units' heaters (39%). OSTUM's results are in agreement with those of a process simulation model developed by CanmetENERGY, other literature, and confidential data of a commercial upgrading operation. For the application of the model, emissions are found to be most sensitive to the amount of natural gas utilized as feedstock by the steam methane reformer. OSTUM is capable of evaluating the impact of different technologies, feedstock qualities, operating conditions, and fuel mixes on upgrading emissions, and its life cycle perspective allows easy incorporation of results into well-to-wheel analyses.

MECHANICAL REGENERATION OF SAND WASTE

Directory of Open Access Journals (Sweden)

D. I. Gnir

2005-01-01

Full Text Available The experimental activation of the sand regenerator of the firm SINTO is carried out at ОАО “MZOO". It is shown that sand grains are cleared from films of binding agents, that allows to use the treated sand for preparation of agglutinant and core sands.

The influence of groundwater depth on coastal dune development at sand flats close to inlets

Science.gov (United States)

Silva, Filipe Galiforni; Wijnberg, Kathelijne M.; de Groot, Alma V.; Hulscher, Suzanne J. M. H.

2018-05-01

A cellular automata model is used to analyze the effects of groundwater levels and sediment supply on aeolian dune development occurring on sand flats close to inlets. The model considers, in a schematized and probabilistic way, aeolian transport processes, groundwater influence, vegetation development, and combined effects of waves and tides that can both erode and accrete the sand flat. Next to three idealized cases, a sand flat adjoining the barrier island of Texel, the Netherlands, was chosen as a case study. Elevation data from 18 annual LIDAR surveys was used to characterize sand flat and dune development. Additionally, a field survey was carried out to map the spatial variation in capillary fringe depth across the sand flat. Results show that for high groundwater situations, sediment supply became limited inducing formation of Coppice-like dunes, even though aeolian losses were regularly replenished by marine import during sand flat flooding. Long dune rows developed for high sediment supply scenarios which occurred for deep groundwater levels. Furthermore, a threshold depth appears to exist at which the groundwater level starts to affect dune development on the inlet sand flat. The threshold can vary spatially depending on external conditions such as topography. On sand flats close to inlets, groundwater is capable of introducing spatial variability in dune growth, which is consistent with dune development patterns found on the Texel sand flat.

Crushed rock sand – An economical and ecological alternative to natural sand to optimize concrete mix

Directory of Open Access Journals (Sweden)

Sanjay Mundra

2016-09-01

Full Text Available The study investigates the use of crushed rock sand as viable alternative to Natural River sand that is being conventionally used as fine aggregate in cement concrete. Various mix designs were developed for different grades of concrete based on IS, ACI and British codes using Natural River sand and crushed rock sand. In each case, the cube compressive strength test, and beam flexure tests were conducted. The results of the study show that, the strength properties of concrete using crushed rock sand are nearly similar to the conventional concrete. The study has shown that crushed stone sand can be used as economic and readily available alternative to river sand and can therefore help to arrest the detrimental effects on the environment caused due to excessive mining of river sand.

Mechanical evaluation of a new sand control screen for SAGD applications

Energy Technology Data Exchange (ETDEWEB)

Woiceshyn, G. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Absolute Completion Technologies, Calgary, AB (Canada); Toffanin, E. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[Schlumberger Canada Ltd., Calgary, AB (Canada); Xie, J.; Wagg, B. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[C-FER Technologies, Edmonton, AB (Canada); Fan, C. [C-FER Technologies, Edmonton, AB (Canada)

2008-10-15

Steam assisted gravity drainage (SAGD) wells normally require the deployment of an open hole completion combining sand control with adequate mechanical strength to withstand aggressive installation loads and serve operational loads. Slotted liners have traditionally been used in western Canada, mainly because of low cost relative to wire-wrapped screen or premium mesh screens. However, slotting base pipe can weaken the mechanical strength. The slot width can also change as the liner deforms under certain load conditions. Operators are therefore interested in alternative technologies to reduce incidents of mechanical failure and loss of sand control of slotted liners in SAGD wells. This paper presented the flush absolute cartridge system (FACS), a newly developed sand screen onto which a 25.4 diameter fusion bonded metal laminate cartridge is directly mounted and secured directly into the base pipe wall. The paper discussed a finite element analysis study that was conducted in order to independently quantify its mechanical strength and integrity for use in SAGD operations. The paper described the liner, as well as the disc geometry, construction and properties. The paper also listed the potential applications for FACS screens and provided a description of the finite element analysis. It was concluded that although FACS satisfies the basic operational criteria, it has very limited ability to absorb additional strain at the end of the thermal cycle. 10 refs., 4 tabs., 22 figs.

Phase behavior of methane hydrate in silica sand

International Nuclear Information System (INIS)

Sun, Shi-Cai; Liu, Chang-Ling; Ye, Yu-Guang; Liu, Yu-Feng

2014-01-01

Highlights: • Hydrate p-T trace in coarse-grained sediment is consistent with that in bulk water. • Fine-grained sediment affects hydrate equilibrium for the depressed water activity. • Hydrate equilibrium in sediment is related to the pore size distribution. • The application of hydrate equilibrium in sediment depends on the actual condition. -- Abstract: Two kinds of silica sand powder with different particle size were used to investigate the phase behavior of methane hydrate bearing sediment. In coarse-grained silica sand, the measured temperature and pressure range was (281.1 to 284.2) K and (5.9 to 7.8) MPa, respectively. In fine-grained silica sand, the measured temperature and pressure range was (281.5 to 289.5) K and (7.3 to 16.0) MPa, respectively. The results show that the effect of coarse-grained silica sand on methane hydrate phase equilibrium can be ignored; however, the effect of fine-grained silica sand on methane hydrate phase equilibrium is significant, which is attributed to the depression of water activity caused by the hydrophilicity and negatively charged characteristic of silica particle as well as the pore capillary pressure. Besides, the analysis of experimental results using the Gibbs–Thomson equation shows that methane hydrate phase equilibrium is related to the pore size distribution of silica sand. Consequently, for the correct application of phase equilibrium data of hydrate bearing sediment, the geological condition and engineering requirement should be taken into consideration in gas production, resource evaluation, etc

Pan Am tar sand bid revealed

Energy Technology Data Exchange (ETDEWEB)

Gray, E

1968-12-16

Muskeg Oil Co., wholly-owned subsidiary of Pan American Canada Oil Co. Ltd., hopes to expand its proposed initial 8,000 bpd in situ Athabasca tar sand production scheme to an ultimate rate of 60,000 bpd. The Muskeg recovery process involves an in situ combustion technique developed by Pan American and applied successfully in experimental work in the Athabasca area. The underground burning process develops heat in the formation, reduces crude bitumen viscosity, and displaces the bitumen to the producing wells. Core analyses have been used to determine bitumen in place, wherever possible. Values for uncored wells were based on logs, through development of an empirical relationship between formation resistivity measured by focused logging devices and bitumen content determined by core analysis. The proposed recovery process is a 10-acre well spacing with 9-spot configuration. The McMurray Formation will be fractured hydraulically and preheated by a combustion process. The bitumen will be recovered by a combustion displacement process utilizing air and water.

Effectiveness of Protective Action of Coatings from Moisture Sorption into Surface Layer of Sand Moulds

Directory of Open Access Journals (Sweden)

Kaźnica N.

2016-12-01

Full Text Available The results of investigations of the sorption process of surface layers of sand moulds covered by zirconium and zirconium - graphite alcohol coatings are presented in the paper. Investigations comprised two kinds of sand grains (silica sand and reclaimed sand of moulding sand with furan resin. Tests were performed under conditions of a high relative air humidity 75 - 85% and a constant temperature within the range 28 – 33°C. To evaluate the effectiveness of coatings protective action from moisture penetration into surface layers of sand moulds gravimetric method of quantitavie moisture sorption and ultrasonic method were applied in measurements.

Photochemical model evaluation of the ground-level ozone impacts on ambient air quality and vegetation health in the Alberta oil sands region: Using present and future emission scenarios

Science.gov (United States)

Vijayaraghavan, Krish; Cho, Sunny; Morris, Ralph; Spink, David; Jung, Jaegun; Pauls, Ron; Duffett, Katherine

2016-09-01

One of the potential environmental issues associated with oil sands development is increased ozone formation resulting from NOX and volatile organic compound emissions from bitumen extraction, processing and upgrading. To manage this issue in the Athabasca Oil Sands Region (AOSR) in northeast Alberta, a regional multi-stakeholder group, the Cumulative Environmental Management Association (CEMA), developed an Ozone Management Framework that includes a modelling based assessment component. In this paper, we describe how the Community Multi-scale Air Quality (CMAQ) model was applied to assess potential ground-level ozone formation and impacts on ambient air quality and vegetation health for three different ozone precursor cases in the AOSR. Statistical analysis methods were applied, and the CMAQ performance results met the U.S. EPA model performance goal at all sites. The modelled 4th highest daily maximum 8-h average ozone concentrations in the base and two future year scenarios did not exceed the Canada-wide standard of 65 ppb or the newer Canadian Ambient Air Quality Standards of 63 ppb in 2015 and 62 ppb in 2020. Modelled maximum 1-h ozone concentrations in the study were well below the Alberta Ambient Air Quality Objective of 82 ppb in all three cases. Several ozone vegetation exposure metrics were also evaluated to investigate the potential impact of ground-level ozone on vegetation. The chronic 3-months SUM60 exposure metric is within the CEMA baseline range (0-2000 ppb-hr) everywhere in the AOSR. The AOT40 ozone exposure metric predicted by CMAQ did not exceed the United Nations Economic Commission for Europe (UN/ECE) threshold of concern of 3000 ppb-hr in any of the cases but is just below the threshold in high-end future emissions scenario. In all three emission scenarios, the CMAQ predicted W126 ozone exposure metric is within the CEMA baseline threshold of 4000 ppb-hr. This study outlines the use of photochemical modelling of the impact of an industry (oil

Applications of sand control technology in thermal recovery systems

Energy Technology Data Exchange (ETDEWEB)

Rensvold, R F

1982-01-01

The ever-increasing application of thermal methods to recover low gravity crude oil has warranted the review of existing sand control techniques relative to their compatibility with high temperature environments. The advantages and limitations of a large number of materials are considered. Carrying fluids, granular pack solids, clay stabilizers, and resin-coated pack sands are discussed. Resins used for in situ sand consolidation processes also are reviewed, and their suitability for application in a high temperature steam environment is evaluated. The effects of highly deviated boreholes on the placement of pressure packs also are considered. Full scale gravel pack model studies have provided valuable clues to the procedures and materials that help to create optimum pressure packs. 58 references.

Rheological Characterization of Green Sand Flow

DEFF Research Database (Denmark)

Jabbaribehnam, Mirmasoud; Spangenberg, Jon; Hovad, Emil

2016-01-01

The main aim of this paper is to characterize experimentally the flow behaviour of the green sand that is used for casting of sand moulds. After the sand casting process is performed, the sand moulds are used for metal castings. The rheological properties of the green sand is important to quantif...

Rheology of oil sands slurries

Energy Technology Data Exchange (ETDEWEB)

Chow, R.; Zhou, J. [Alberta Research Council, Edmonton, AB (Canada). Mineral Oil Sands Unit; Wallace, D. [Dean Wallace Consulting Inc., Beaumont, AB (Canada)

2006-07-01

This study focused on integrating rheology and colloid science to improve recovery of bitumen in surface mined oil sands. Factors that influence recovery, such as conditions of particle interaction, solids concentration and shear rate, were reviewed. In an effort to understand the rheological behaviour of clay-in-water suspensions, an elaborate procedure was developed to separate an inter-bedded clay layer from a site at Albian Sands Energy Inc. The variables were water chemistry, solids concentration, and shear rate. The research study was conducted at the Alberta Research Council with the support of the CONRAD Extraction Group. A controlled stress rheometer was used to provide the quantitative evaluations of the clay slurry properties. The research results indicate that the viscoelastic properties of the slurry are highly influenced by the shear history of the slurry, solids content, calcium concentration, and sample aging. Shear thinning behaviour was observed in all slurry samples, but the slurry viscosity increased with test time for a given shear rate. In order to classify the slurries, a method was developed to distinguish the gel strength. The slurries were then classified into 3 distinct patterns, including no gel, weak gel and strong gel. The evolution of the experimental protocols were described along with the current stability maps that correlate the domains of the gel strength according to the solids concentration, calcium ion content, and shear rate. It was concluded that the rheological properties of oil sands slurries influence bitumen recovery in commercial surface-mined oil sands operations. tabs., figs.

Contribution of sand-associated enterococci to dry weather water quality.

Science.gov (United States)

Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J

2015-01-06

Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions.

Application of toxicity testing in the evaluation of reclamation options for oil sands fine tails

International Nuclear Information System (INIS)

Nelson, L.R.; MacKinnon, M.; Gulley, J.R.

1993-01-01

The hot water process for the extraction of bitumen from oil sands leads to the production of large volumes of wastewater and the formation of a large inventory of fine clay tailings. This fine tailings material and its associated water are acutely toxic to various aquatic test organisms during bioassays. An overview is presented of toxicity testing at Syncrude and Suncor, the application of toxicity testing to fine tailings management, and the role in reclamation planning. The main acutely toxic component of the tailings is the polar organic acid fraction, specifically naphthanates. These naphthanates are readily degraded biologically by indigenous microbial populations. Toxicity testing is aimed at assessing the degree of both acute and chronic toxicity and the long term potential for the input of toxins into the environment from various proposed reclamation measures. 28 refs., 6 figs., 2 tabs

Oil sands tailings preliminary ecological risk assessment

International Nuclear Information System (INIS)

1994-01-01

Chemical data collected from various oil sands soil-tailings mixtures were used to determine the ecological risk that such tailings would pose to terrestrial wildlife at the surface of a reclaimed site. A methodology that could be used to evaluate the risks posed by various reclamation options (for dry land only) was proposed. Risks associated with other reclamation options, such as wet landscapes or deeper in-pit disposal, were not evaluated. Ten constituents (eight organic and two inorganic) were found to pose a threat to terrestrial biota. The relative contribution of different exposure pathways (water and food ingestion, incidental soil ingestion, inhalation) were studied by probabilistic models. Some physical and chemical reclamation alternatives which involve incorporating oil sands tailings in the landscape to produce a surface that could sustain a productive ecosystem, were described. 53 refs., 15 tabs., 3 figs

Ground penetrating radar water content mapping of golf course green sand layers

Science.gov (United States)

Information on the spatial distribution of water content across the sand layer component of a golf course green can be important to golf course superintendents for evaluating drainage effectiveness and scheduling irrigation. To estimate the bulk water content of the sand layer at point locations ac...

The Alberta oil sands story

Energy Technology Data Exchange (ETDEWEB)

1974-01-01

This report serves as a detailed introduction to the Alberta oil sands and their development. It includes a description of the oil sands deposits, an outline of crude bitumen recovery and upgrading processes, the role of Alberta Energy Company in oil sands development, environmental aspects, manpower requirements for oil sands development, research needs, and further oil sands projects. Presently proven recoverable reserves in the oil sands amount to 26.5 billion bbl of synthetic crude. Production from the Syncrude plant (125,000 bbl/d capacity) is expected to begin in 1977, followed by a Shell Canada operation around 1980. The provincial government will participate in the oil sand industry through its joint venture participation in Syncrude and its 50% share in Alberta Energy Company; the latter company participates in related aspects of the Syncrude project, such as pipelines. The result of Alberta's participation in the industry will mean that, directly or indirectly, the province will realize 60% of the total profits. The job creation potential of oil sands projects is estimated to be extensive, with a direct and indirect work force supported by oil sands activities possibly reaching 180,000 persons by the year 2000. Research needs have been identified, particularly in the area of in-situ thermal recovery technology, and the creation of the Alberta Oil Sands Technology and Research Authority has been authorized in order to meet these needs. Although current reserves are sufficient to support 20-30 synthetic crude plants, a number of factors will limit expansion of the industry. 8 figs., 5 tabs.

Method of treating non-supporting underground formations

International Nuclear Information System (INIS)

Anderson, B.W.; Trotty, K.D.

1977-01-01

Method of treating non-supporting underground formations, through which passes a borehole, aimed at preventing the transport of sand particles from the formation into the borehole during conveyance of liquids. (orig./RW) [de

Augmenting Sand Simulation Environments through Subdivision and Particle Refinement

Science.gov (United States)

Clothier, M.; Bailey, M.

2012-12-01

Recent advances in computer graphics and parallel processing hardware have provided disciplines with new methods to evaluate and visualize data. These advances have proven useful for earth and planetary scientists as many researchers are using this hardware to process large amounts of data for analysis. As such, this has provided opportunities for collaboration between computer graphics and the earth sciences. Through collaboration with the Oregon Space Grant and IGERT Ecosystem Informatics programs, we are investigating techniques for simulating the behavior of sand. We are also collaborating with the Jet Propulsion Laboratory's (JPL) DARTS Lab to exchange ideas and gain feedback on our research. The DARTS Lab specializes in simulation of planetary vehicles, such as the Mars rovers. Their simulations utilize a virtual "sand box" to test how a planetary vehicle responds to different environments. Our research builds upon this idea to create a sand simulation framework so that planetary environments, such as the harsh, sandy regions on Mars, are more fully realized. More specifically, we are focusing our research on the interaction between a planetary vehicle, such as a rover, and the sand beneath it, providing further insight into its performance. Unfortunately, this can be a computationally complex problem, especially if trying to represent the enormous quantities of sand particles interacting with each other. However, through the use of high-performance computing, we have developed a technique to subdivide areas of actively participating sand regions across a large landscape. Similar to a Level of Detail (LOD) technique, we only subdivide regions of a landscape where sand particles are actively participating with another object. While the sand is within this subdivision window and moves closer to the surface of the interacting object, the sand region subdivides into smaller regions until individual sand particles are left at the surface. As an example, let's say

Occupational exposure to natural radioactivity in a zircon sand milling plant

International Nuclear Information System (INIS)

Ballesteros, Luisa; Zarza, Isidoro; Ortiz, Josefina; Serradell, Vicente

2008-01-01

Raw zirconium sand is one of the substances (naturally occurring radioactive material, NORM) which is widely used in the ceramic industry. This sand contains varying concentrations of natural radionuclides: mostly U-238 but also Th-232 and U-235, together with their daughters, and therefore may need to be regulated by Directive 96/29/EURATOM. This paper describes the method used to perform the radiological study on a zircon sand milling plant and presents the results obtained. Internal and external doses were evaluated using radioactivity readings from sand, airborne dust, intermediate materials and end products. The results on total effective dose show the need for this type of industry to be carefully controlled, since values near to 1 mSv were obtained

Occupational exposure to natural radioactivity in a zircon sand milling plant

Energy Technology Data Exchange (ETDEWEB)

Ballesteros, Luisa [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: lballest@upvnet.upv.es; Zarza, Isidoro [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: iszarpe@upvnet.upv.es; Ortiz, Josefina [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: jortiz@iqn.upv.es; Serradell, Vicente [Laboratorio de Radioactividad Ambiental, Universidad Politecnica de Valencia, Apartado 22012, E-46071 Valencia (Spain)], E-mail: vserradell@iqn.upv.es

2008-10-15

Raw zirconium sand is one of the substances (naturally occurring radioactive material, NORM) which is widely used in the ceramic industry. This sand contains varying concentrations of natural radionuclides: mostly U-238 but also Th-232 and U-235, together with their daughters, and therefore may need to be regulated by Directive 96/29/EURATOM. This paper describes the method used to perform the radiological study on a zircon sand milling plant and presents the results obtained. Internal and external doses were evaluated using radioactivity readings from sand, airborne dust, intermediate materials and end products. The results on total effective dose show the need for this type of industry to be carefully controlled, since values near to 1 mSv were obtained.

Engineering assessment of radioactive sands and residues, Lowman Site, Lowman, Idaho

International Nuclear Information System (INIS)

1981-09-01

Ford, Bacon and Davis Utah Inc. has reevaluated the Lowman site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive sands and residues at Lowman, Idaho. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of radioactive sands and residues and radiation exposure of individuals and nearby populations, and investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 191,000 tons of radioactive sands, residues, and contaminated soils at the Lowman site constitutes the most significant environmental impact, although windblown radioactive sands and external gamma radiation also are factors

Holocene beach buildup and coastal aeolian sand incursions off the Nile littoral cell

Science.gov (United States)

Roskin, Joel; Sivan, Dorit; Shtienberg, Gilad; Porat, Naomi; Bookman, Revital

2017-04-01

gradually expanded to the current limits of today's dune fields. The gradual but unsteady post-Byzantine demographic drop enabled reestablishment of natural vegetation and rapid regosol development. This drop occurred differentially along the coast due to governance and land-use practices. We suggest that dune construction mainly evolved around the 19th century from the existing sand sheets and low dunes that intermittently developed since 6-5 ka. Human (Bedouin grazing influx and ethnic settlements) destruction of vegetation, in conjuction with the rapid 19th-20th century population growth made the sand prone to "in situ" transverse and linear dune formation in response to powerful winds further supported by increased storminess at this time. Inland dune mobilization and the artificial establishment of vegetated foredunes along the coast in the 1930's-1940's partly scalped the sand deposits by the coast.

Thermoluminescence dating of Rio Claro and Piracununga formations

International Nuclear Information System (INIS)

Ferreira, Sandra Regina; Chang, Maria Rita Caetano

2008-01-01

The Rio Claro and Piracununga formations cover extensive areas of the Paulista Peripheral Depression, dominantly in the region of Rio Claro and Piracununga cities. These units lie over the Corumbatai and Piramboia formations, exhibiting discordant contacts. The Rio Claro and Piracununga formations are composed of fine to medium sand facies, showing local cross-stratifications and parallel beddings with thin interbeddings of mud and gravel. These sands were dated by the Thermoluminescence Method, which indicated they were from the Pleistocene age. The oldest age (745,000 years BP) was found in deposits of the Rio Claro Formation; the other ages varied from 400,000 years BP to 145,000 years BP, for both formations. The youngest age (15,000 years BP - close to Pleistocene/ Holocene limit) was found in colluvial deposits, which rest on the Piracununga Formation. (author)

Economic impacts of Alberta's oil sands, volume 1

International Nuclear Information System (INIS)

Timilsina, G.R.; LeBlanc, N.; Walden, T.

2005-01-01

In 2004, the international media recognized Alberta's oil sands as part of the global oil reserves, thereby establishing Canada as second to Saudi Arabia as potential oil producing nations. The economic impacts of Alberta's oil sands industry on economies were assessed at regional, provincial and international levels for the 2000 to 2020 period. A customized input-output model was used to assess economic impacts, which were measured in terms of changes in gross domestic product; employment and labour income; and, government revenues. Cumulative impacts on employment by sector and by jurisdiction were also presented. An investment of $100 billion is expected through 2020, resulting in production of crude bitumen and synthetic crude oil outputs valued at about $531 billion. The impact of the oil sands industry on local employment was also evaluated. It was shown that activities in the oil sands industry will lead to significant economic impact in Alberta, Ontario, Quebec and the rest of Canada. Alberta's local economy would be the main beneficiary of oil sands activities with nearly 3.6 million person years employment created in Alberta during the 2000 to 2020. Another 3 million person years employment would be created in other Canadian provinces and outside Canada during the same time period. A sensitivity analysis on the responsiveness to oil prices and the removal of various constraints incorporated in the main analysis was also presented. The federal government will be the largest recipient of revenues generated to to oil sands activities. The results of the study were compared with that of the National Task Force on Oil Sands Strategies. This first volume revealed the results of the study while the second volume includes the data and detailed results. 48 refs., 57 tabs., 28 figs

Compressive behavior of fine sand.

Energy Technology Data Exchange (ETDEWEB)

Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

2010-04-01

The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

The Rheology of Acoustically Fluidized Sand

Science.gov (United States)

Conrad, J. W.; Melosh, J.

2013-12-01

The collapse of large craters and the formation of central peaks and peak rings is well modeled by numerical computer codes that incorporate the acoustic fluidization mechanism to temporarily allow the fluid-like flow of rock debris immediately after crater excavation. Furthermore, long runout landslides require a similar mechanism to explain their almost frictionless movement, which is probably also a consequence of their granular composition coupled with internal vibrations. Many different investigators have now confirmed the ability of vibrations to fluidize granular materials. Yet it still remains to fully describe the rheology of vibrated sand as a function of stress, frequency and amplitude of the vibrations in the sand itself. We constructed a rotational viscometer to quantitatively investigate the relation between the stress and strain rate in a horizontal bed of strongly vibrated sand. In addition to the macroscopic stain rate, the amplitude and frequency of the vibrations produced by a pair of pneumatic vibrators were also measured with the aid of miniaturized piezoelectric accelerometers (B&K 4393) whose output was recorded on a digital storage oscilloscope. The initial gathering of the experimental data was difficult due to granular memory, but by having the sand compacted vibrationally for 8 minutes before each run the scatter of data was reduced and we were able to obtain consistent results. Nevertheless, our major source of uncertainty was variations in strain rate from run to run. We find that vibrated sand flows like a highly non-Newtonian fluid, in which the shear strain rate is proportional to stress to a power much greater than one, where the precise power depends on the amplitude and frequency of the applied vibrations. Rapid flow occurs at stresses less than half of the static yield stress (that is, the yield stress when no vibration is applied) when strong vibrations are present. For a Newtonian fluid, such as water, the relation between

Characterization of Coated Sand Cores from Two Different Binder Systems for Grey Iron Castings

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Poulsen, Thomas

or veining and metal penetration defects. The use of refractory coatings on cores is fundamental to obtaining acceptable casting surface quality and is used on resin bonded cores in production foundries. In this study new sol gel-coated sand cores made from coldbox and furan binder systems were investigated......Expansion defects on the surface of the castings include sand burn-in, metal penetration and/or veining, finning or scab. Veining or finning and metal penetration are of interest. These defects are associated with silica sand and result from the penetration of liquid metal into cracks formed during...... differential expansion of the core during heating. The rapid expansion of silica sand up to 600 oC and especially at 573 oC, where the α – β phase transformation occurs, is the cause of stresses in the core system. These stresses cause crack formation and metal melt flows into these cracks causing finning...

Arsenic Removal from Drinking Water by Absorptive Media-U.S. EPA Demonstration Project at Desert Sands MDWCA, NM Final Performance Evaluation Report

Science.gov (United States)

This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at the Desert Sands Mutual Domestic Water Consumers Association (MDWCA) facility in Anthony, NM. The objectives of the project were to evalu...

Contemporary sand wedge development in seasonally frozen ground and paleoenvironmental implications

Science.gov (United States)

Wolfe, Stephen A.; Morse, Peter D.; Neudorf, Christina M.; Kokelj, Steven V.; Lian, Olav B.; O'Neill, H. Brendan

2018-05-01

Contemporary sand wedges and sand veins are active in seasonally frozen ground within the extensive discontinuous permafrost zone in Northwest Territories, Canada. The region has a subarctic continental climate with 291 mm a-1 precipitation, -4.1 °C mean annual air temperature, warm summers (July mean 17.0 °C), and cold winters (January mean -26.6 °C). Five years of continuous observations indicate that interannual variation of the ground thermal regime is dominantly controlled by winter air temperature and snow cover conditions. At sandy sites, thin snow cover and high thermal conductivity promote rapid freezing, high rates of ground cooling, and low near-surface ground temperatures (-15 to -25 °C), resulting in thermal contraction cracking to depths of 1.2 m. Cracking potentials are high in sandy soils when air temperatures are air temperatures are ≤-17 °C, and snow cover is conditions in peatlands maintain permafrost, but thermal contraction cracking does not occur because thicker snow cover and the thermal properties of peat prolong freezeback and maintain higher winter ground temperatures. A combination of radiocarbon dating, optical dating, and stratigraphic observations were used to differentiate sand wedge types and formation histories. Thermal contraction cracks that develop in the sandy terrain are filled by surface (allochthonous) and/or host (autochthonous) material during the thaw season. Epigenetic sand wedges infilled with allochthonous sand develop within former beach sediments beneath an active eolian sand sheet. Narrower and deeper syngenetic wedges developed within aggrading eolian sand sheets, whereas wider and shallower antisyngenetic wedges developed in areas of active erosion. Thermal contraction cracking beneath vegetation-stabilized surfaces leads to crack infilling by autochthonous host and overlying organic material, with resultant downturning and subsidence of adjacent strata. Sand wedge development in seasonally frozen ground

Evaluation for swelling characteristics of buffer and backfill materials for high-level nuclear waste disposal. Influence of sand-bentonite content and cation compositions in bentonite

International Nuclear Information System (INIS)

Komine, Hideo; Ogata, Nobuhide

1999-01-01

Compacted bentonite and sand-bentonite mixture are attracting greater attention as buffer and backfill materials for disposal pits and access tunnels in the underground facilities for repositories of high-level nuclear waste. Buffer and backfill materials must have the swelling characteristics and are expected to fill up the space between these materials and surrounding ground by swelling. This role is called as 'Self-sealing'. To design the specifications, such as dry density, bentonite content and size, of buffer and backfill materials for the disposal facilities of high-level nuclear wastes described above, we must evaluate the swelling characteristics of compacted bentonite and sand-bentonite mixtures. For this purpose, this study proposed the evaluation formula for swelling characteristics of buffer and backfill materials containing bentonite. This study derived new equations for evaluating the relationship between the swelling deformation of compacted bentonite and sand-bentonite mixtures, and the swelling behavior of montmorillonite minerals, which are swelling clay minerals. This study also proposed new equations for evaluating the ion compositions of bentonite, ion concentration of pore water and the specific surface of bentonite, which significantly influence the swelling characteristics of buffer and backfill materials. The evaluation formula proposed in this study is presented by combining the above-mentioned new equations with theoretical equations, of which are the Gouy-Chapman diffuse double layer theory and the van der Waals force, of repulsive and attractive forces of montmorillonite minerals. (author)

On Pluvial Compaction of Sand

DEFF Research Database (Denmark)

Jacobsen, Moust

At the Institute of Civil Engineering in Aalborg model tests on dry sand specimens have been carried out during the last five years. To reduce deviations in test results, the sand laying technique has been carefully studied, and the sand mass spreader constructed. Preliminary results have been...

MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

Directory of Open Access Journals (Sweden)

Lucimar Arruda Viana

Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

Removal of heavy metals using a microbial active, continuously operated sand filter

International Nuclear Information System (INIS)

Ebner, C.

2001-01-01

Heavy metals play an important role within the spectrum of the various pollutants, emitted into the environment via human activities. In contrast to most organic pollutants, heavy metal can not be degraded. Many soils, lakes and rivers show a high contamination with heavy metals due to the enrichment of these pollutants. In addition to existing chemical-physical and biological technologies for the treatment of heavy metal containing waste waters a demand for new, efficient and low-cost cleaning technologies exists, particularly for high volumes of weakly contaminated waters. Such a technology was developed within the framework of a scientific project of the European Union. The approach makes use of a continuously operated, moving-bed Astrasand filter, which has been operated as a continuous biofilm reactor. By inoculation of the reactor with bacteria providing different, defined mechanisms of metal immobilization, and by continuous supply of suitable nutrients, a metal-immobilizing biofilm is built up and regenerated continuously. Metal-enriched biomass is removed continuously from the system, and the contained metals can be recycled by pyrometallurgical treatment of the biomass. The subjects of the present work were the optimization of the nutrient supply for the process of metal removal, the investigation of the toxicity of different waste waters, the optimization of inoculation and biofilm formation, set-up and operation of a lab scale sand filter and the operation of a pilot scale sand filter treating rinsing water of a chemical nickel plating plant. First, basic parameters like toxicity of heavy metal-containing waste waters and the influence of the nutrition of bacteria on biosorption and total metal removal were examined, using freely suspended bacteria in batch culture. Concerning toxicity great differences could be found within the spectrum of heavy metal-containing waste waters tested. Some waters completely inhibited growth, while others did not

The effect of oil sands tailings pond sediments on embryo-larval walleye (Sander vitreus).

Science.gov (United States)

Raine, J C; Turcotte, D; Tumber, V; Peru, K M; Wang, Z; Yang, C; Headley, J V; Parrott, J L

2017-10-01

Walleye (Sander vitreus) are a commercially important North American fish species that inhabit the Athabasca River. This river flows through the Athabasca oil sands where natural sources of bitumen erode from the McMurray formation. Little information is available on responses of walleye embryos to oil sands tailings pond sediments in a laboratory setting. The current study describes the design and implementation of a daily-renewal bioassay to assess the potential effects of tailings pond sediments from the Athabasca oil sands area on walleye development. Developing walleye embryos were exposed to increasing concentrations of two tailings pond sediments (collected in the Athabasca oil sands area) until the completion of yolk absorption in control fish. Sediments from the tailings pond represent a mixture of polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs. During the 31 day exposure, the walleye were examined for mortalities, weight, length and developmental abnormalities to provide an initial evaluation of the effects of the oil sands tailings pond sediments. Walleye embryo survival differed between the tailings pond sediments, and survival decreased with increasing sediment concentration. Alkylated PAH content differed between the two tailings pond sediments and lower embryo survival corresponded to higher total and alkylated PAH content. Tailings pond sediment-exposed walleye exhibited a delay in development, as well as increased percentages of larvae with heart and yolk sac edema, and cranial and spinal malformations. These abnormalities in development are often associated with PAH and alkylated PAH exposure. This study provides an exposure design that can be used to assess sediment toxicity to early developmental stages of a fish species not commonly tested in the lab, and lays the groundwork for future studies with this and other difficult-to-culture species. These results offer information on the potential effects of tailings pond sediments

Numerical Evaluation on the Different Shapes of Gravelly Sand Columns to Increase the Loading Capacity of Soft Clay

Directory of Open Access Journals (Sweden)

Meghzili Sif Allah

2017-01-01

Full Text Available Improvement on soft clay by the installation of stone column is one of the most popular methods followed worldwide. Different analytical and numerical solutions have already been developed for understanding the load transfer mechanism of soft soil reinforced with stone column. This study investigated a bearing capacity of the gravelly sand column, installed in soft clay bed at 15kpa of undrained shear strength. The column variable of length and diameter ratio at 7, 8 and 9 were evaluated. On top of that, the combination of two diameters in single column was tested and the uniform diameter was used as a control. In the numerical analysis, Mohrcoulomb model was adopted in the idealization of the behaviour of the gravelly sand column and soft clay materials. The results revealed that the optimum design that gave the highest loading capacity of the combination 11=12 of column diameter was the length and diameter ratio of 8.

Bituminous sands : tax issues

International Nuclear Information System (INIS)

Patel, B.

2004-01-01

This paper examined some of the tax issues associated with the production of bitumen or synthetic crude oil from oil sands. The oil sands deposits in Alberta are gaining more attention as the supplies of conventional oil in Canada decline. The oil sands reserves located in the Athabasca, Cold Lake and Peace River areas contain about 2.5 trillion barrels of highly viscous hydrocarbons called bitumen, of which nearly 315 billion barrels are recoverable with current technology. The extraction method varies for each geographic area, and even within zones and reservoirs. The two most common extraction methods are surface mining and in-situ extraction such as cyclic steam stimulation (CSS); low pressure steam flood; pressure cycle steam drive; steam assisted gravity drainage (SAGD); hot water flooding; and, fire flood. This paper also discussed the following general tax issues: bituminous sands definition; bituminous sands leases and Canadian development expense versus Canadian oil and gas property expense (COGPE); Canadian exploration expense (CEE) for surface mining versus in-situ methods; additional capital cost allowance; and, scientific research and experimental development (SR and ED). 15 refs

Oil sands tax expenditures

International Nuclear Information System (INIS)

Ketchum, K; Lavigne, R.; Plummer, R.

2001-01-01

The oil sands are a strategic Canadian resource for which federal and provincial governments provide financial incentives to develop and exploit. This report describes the Oil Sands Tax Expenditure Model (OSTEM) developed to estimate the size of the federal income tax expenditure attributed to the oil sands industry. Tax expenditures are tax concessions which are used as alternatives to direct government spending for achieving government policy objectives. The OSTEM was developed within the business Income Tax Division of Canada's Department of Finance. Data inputs for the model were obtained from oil sands developers and Natural Resources Canada. OSTEM calculates annual revenues, royalties and federal taxes at project levels using project-level projections of capital investment, operating expenses and production. OSTEM calculates tax expenditures by comparing taxes paid under different tax regimes. The model also estimates the foregone revenue as a percentage of capital investment. Total tax expenditures associated with investment in the oil sands are projected to total $820 million for the period from 1986 to 2030, representing 4.6 per cent of the total investment. 10 refs., 2 tabs., 7 figs

In situ radionuclide migration studies in a shallow sand aquifer (Part 1)

International Nuclear Information System (INIS)

Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

1985-07-01

As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been contructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl, detected using a specific ion electrode) and iodine-131 (as NaI, detected radiometrically using a NaI (T1) crystal). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjuction with 131 I. The principal research objectives of the programme are as follows:- (1) to undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) to identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) to obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. (author)

Influence of the reclamation method of spent moulding sands on the possibility of creating favourable conditions for gases flow in a mould

Directory of Open Access Journals (Sweden)

Łucarz M.

2017-03-01

Full Text Available The results of investigations concerning the influence of the applied sand matrix (fresh sand, reclaim on the properties of moulding sands used for production of large dimensional castings (ingot moulds, ladles, are presented in the hereby paper. The performed investigations were aimed at determining the influence of various reclamation methods of spent moulding sands on the quality of the obtained reclaimed material. Moulding sands were prepared on the fresh quartz matrix as well as on sand matrices obtained after various reclamation methods. The selected moulding sand parameters were tested (strength, permeability, grindability, ignition losses, pH reactions. It can be stated, on the basis of the performed investigations, that the kind of the applied moulding sand matrix is of an essential meaning from the point of view of creating conditions minimising formation of large amounts of gases and their directional migration in a casting mould.

Delineating chalk sand distribution of Ekofisk formation using probabilistic neural network (PNN) and stepwise regression (SWR): Case study Danish North Sea field

Science.gov (United States)

Haris, A.; Nafian, M.; Riyanto, A.

2017-07-01

Danish North Sea Fields consist of several formations (Ekofisk, Tor, and Cromer Knoll) that was started from the age of Paleocene to Miocene. In this study, the integration of seismic and well log data set is carried out to determine the chalk sand distribution in the Danish North Sea field. The integration of seismic and well log data set is performed by using the seismic inversion analysis and seismic multi-attribute. The seismic inversion algorithm, which is used to derive acoustic impedance (AI), is model-based technique. The derived AI is then used as external attributes for the input of multi-attribute analysis. Moreover, the multi-attribute analysis is used to generate the linear and non-linear transformation of among well log properties. In the case of the linear model, selected transformation is conducted by weighting step-wise linear regression (SWR), while for the non-linear model is performed by using probabilistic neural networks (PNN). The estimated porosity, which is resulted by PNN shows better suited to the well log data compared with the results of SWR. This result can be understood since PNN perform non-linear regression so that the relationship between the attribute data and predicted log data can be optimized. The distribution of chalk sand has been successfully identified and characterized by porosity value ranging from 23% up to 30%.

Extensive formation of sinkholes in unconsolidated rock due to underground erosive removal of sand at a marginal batter of an opencast mine - causes, process and geotechnical safety measures. Grossflaechige Erdfallbildungen im Lockergestein durch unterirdische erosive Ausraeumung von Sand and einer Tagebauendboeschung - Ursachen, Verlauf und geotechnische Sicherung

Energy Technology Data Exchange (ETDEWEB)

Pfeiffer, H

1991-08-01

When the ground water rose in the marginal batter of an opencast mine damage occurred. This was caused by the processes of internal erosion and suffusion in fine sand layers of slight thickness and by the disintegration of the overlying strata due to the formation of sinkholes. Effective safety measures involved lowering the ground-water level in the zone immediately in front of the area in question and installing an auxiliary filter unit at the marginal batter. (orig.).

Effects of oil sands waste water on the wood frog (rana sylvatica)

Energy Technology Data Exchange (ETDEWEB)

Hersikorn, B.; Smits, J.E. [Saskatchewan Univ., Regina, SK (Canada)

2007-07-01

The sustainability of various reclamation strategies can be determined by the growth and health of indigenous amphibians (Wood Frogs). This paper referred to the large quantities of tailings water that are generated by oil sand extraction activities. It presented the results of a study that was conducted in the spring and summer of 2006 and 2007 on reclaimed formation wetlands comprising tailings water. The objective was to understand the impact of these wetlands on native amphibians. Frogs were exposed to wetlands containing oil sands process affected water (OSPW) and reference water (no OSPW). Six experimental trenches were made at one site in the first year. Each trench had 3 enclosures with 50 tadpoles. In the second year, there were 13 sites, including 6 reference and 7 OSPW affected sites, which were classified as old (more than 8 yrs) or young (less than 7 yrs). Four enclosures, with 50 tadpoles each, were placed in each wetland. The study involved the evaluation of growth rate, survival, time to metamorphosis, thyroid hormone concentrations, liver EROD activity, and tissue retinol concentrations. In addition, stable isotopes were used to track carbon flow from primary production plants, through the food chain, to tadpoles and frogs which represent intermediate and higher trophic levels in reclaimed wetlands.

Singing Sand Dunes

Indian Academy of Sciences (India)

ble low-frequency (s. 75–105 Hz), that can some- times be heard up to 10 km away. Scientific in- vestigations suggest that the sustained low fre- quency sound of sand dunes that resembles a pure note from a musical instrument, is due to the synchronized motion of well-sorted dry sand grains when they spontaneously ...

Naphtha evaporation from oil sands tailings ponds

Energy Technology Data Exchange (ETDEWEB)

Kasperski, K.; Munoz, V.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre

2010-07-01

The environmental impacts of volatile organic compounds (VOCs) from oil sands tailings ponds must be considered when evaluating new oil sands mining and extraction operations. Studies have suggested that only 40 percent of the solvent sent to tailings ponds is available to the environment, while the rest is irreversibly trapped. The recovery of hydrocarbons from oil sands froth process water is low. This PowerPoint presentation discussed a method of distinguishing between water and hydrocarbons at low temperatures. Samples were heated to 246 degrees C at 15 degrees C and held for 10 minutes. Heating was then resumed at 750 degrees C and held for 10 minutes in a pyrolysis phase, then cooled and reheated with an oxygen addition. The method demonstrated that the diluent distribution between the solids and water phases is misinterpreted as diluent that will evaporate, and diluent that will not evaporate. The study concluded by suggesting that the definition of recoverable and unrecoverable hydrocarbon should be re-termed as easily recoverable, and difficult to recover. tabs., figs.

Western Gas Sands Project: stratigrapy of the Piceance Basin

Energy Technology Data Exchange (ETDEWEB)

Anderson, S. (comp.)

1980-08-01

The Western Gas Sands Project Core Program was initiated by US DOE to investigate various low permeability, gas bearing sandstones. Research to gain a better geological understanding of these sandstones and improve evaluation and stimulation techniques is being conducted. Tight gas sands are located in several mid-continent and western basins. This report deals with the Piceance Basin in northwestern Colorado. This discussion is an attempt to provide a general overview of the Piceance Basin stratigraphy and to be a useful reference of stratigraphic units and accompanying descriptions.

Radiation hazards evaluation for selected sand samples from Camburi beach, Vitoria, Espirito Santo, Brazil

International Nuclear Information System (INIS)

Barros, Livia F.; Pecequilo, Brigitte R.S.

2013-01-01

In this work, a single location at Camburi beach, known to be a naturally high background region, was studied. Radiation hazards indexes and annual effective dose were evaluated from the 226 Ra, 232 Th and 40 K sands activities concentrations. Sand samples were monthly collected during 2011, dried, sealed in standard 100 mL HPDE polyethylene flasks and measured by high resolution gamma spectrometry after a 4 weeks in-growth period. The 226 Ra concentration was determined from the weighted average concentrations of 214 Pb and 214 Bi. The 232 Th concentration was determined from the weighted average concentrations of 228 Ac, 212 Pb and 212 Bi and the 4 0K from its single gamma transition. The results, considering samples gamma-rays self-attenuation, show activities concentrations in the range from 6 Bq kg -1 to 39 Bq kg -1 for 226 Ra, 13 Bq kg -1 to 161 Bq kg -1 for 232 Th, and 7 Bq kg -1 to 65 Bq kg -1 for 40 K. The radium equivalent activity for the studied samples ranged from 26 Bq kg -1 to 274 Bq kg - '1. The external and internal hazard indexes varied, respectively, from 0.07 to 0.74 and from 0.09 to 0.85. The annual effective dose values laid from 0.07 mSv.y -1 to 0.72 mSv.y - '1. All values obtained in this work are below the radiological protection recommended limits. (author)

Facilitating participation in formative evaluation supported by effect map

DEFF Research Database (Denmark)

Granlien, Maren Sander

2009-01-01

It has been suggested that formative evaluation should be an integrated part of system implementation in order to improve the outcome of system use. In a design project an approach combining participatory design (PD) and formative evaluation has shown a great potential for improving the design of...... map is applied in an action research study in the Danish health care sector aiming at improving the medication process and the use of the electronic medication record supporting the medication process. ...... designed effect map. The purpose of the effect map is twofold: a) To encourage user participation in the early activities of formative evaluation b) The effects specified can be used as formative evaluation measures and guidance in the process of improving the system. The evaluation approach and the effect...

Western Gas Sands Project. Status report, 1 March 1979--31 March 1979

Energy Technology Data Exchange (ETDEWEB)

None

1979-01-01

Progress of the government-sponsored projects directed toward increasing gas production from low-permeability gas sands of the western United States is summarized. During March, National Laboratories and Energy Technology Centers generally progressed on schedule. Bartlesville Energy Technology Center continued work on fracture conductivity, rock-fluid interaction, and log evaluation techniques. Theoretical and experimental work on hydraulic fracturing mechanics and analysis of well test data continued at Lawrence Livermore Laboratory. Sandia Laboratories completed preparations for the NTS evaluation test of the borehole seismic system. M.D. Wood, Inc. monitored the formation of a hydraulic fracture in the Wattenburg gas field, Weld County, Colorado. Measurement of bottom-hole pressure in the Miller No. 1 and Sprague No. 1 wells for the CIG cyclic gas injection project continued. The Mitchell Energy Corporation Muse--Duke No. 1 was flowing 4,000 MCFD in March. Efforts to clean out Mobil's PCU F31-13G well continued.

Comparing different methods for fast screening of microbiological quality of beach sand aimed at rapid-response remediation.

Science.gov (United States)

Testolin, Renan C; Almeida, Tito C M; Polette, Marcus; Branco, Joaquim O; Fischer, Larissa L; Niero, Guilherme; Poyer-Radetski, Gabriel; Silva, Valéria C; Somensi, Cleder A; Corrêa, Albertina X R; Corrêa, Rogério; Rörig, Leonardo R; Itokazu, Ana Gabriela; Férard, Jean-François; Cotelle, Sylvie; Radetski, Claudemir M

2017-05-15

There is scientific evidence that beach sands are a significant contributor to the pathogen load to which visitors are exposed. To develop beach quality guidelines all beach zones must be included in microbiological evaluations, but monitoring methods for beach sand quality are relatively longstanding, expensive, laborious and require moderate laboratory infrastructure. This paper aimed to evaluate the microorganism activity in different beach zones applying and comparing a classical method of membrane filtration (MF) with two colorimetric screening methods based on fluorescein (FDA) and tetrazolium (TTC) salt biotransformation to evaluate a new rapid and low-cost method for beach sand microbiological contamination assessments. The colorimetric results can help beach managers to evaluate rapidly and at low cost the microbiological quality of different beach zones in order to decide whether remedial actions need to be adopted to prevent exposure of the public to microbes due to beach sand and/or water contamination. Copyright © 2017. Published by Elsevier Ltd.

The Diversity of Yellow-Related Proteins in Sand Flies (Diptera: Psychodidae.

Directory of Open Access Journals (Sweden)

Michal Sima

Full Text Available Yellow-related proteins (YRPs present in sand fly saliva act as affinity binders of bioamines, and help the fly to complete a bloodmeal by scavenging the physiological signals of damaged cells. They are also the main antigens in sand fly saliva and their recombinant form is used as a marker of host exposure to sand flies. Moreover, several salivary proteins and plasmids coding these proteins induce strong immune response in hosts bitten by sand flies and are being used to design protecting vaccines against Leishmania parasites. In this study, thirty two 3D models of different yellow-related proteins from thirteen sand fly species of two genera were constructed based on the known protein structure from Lutzomyia longipalpis. We also studied evolutionary relationships among species based on protein sequences as well as sequence and structural variability of their ligand-binding site. All of these 33 sand fly YRPs shared a similar structure, including a unique tunnel that connects the ligand-binding site with the solvent by two independent paths. However, intraspecific modifications found among these proteins affects the charges of the entrances to the tunnel, the length of the tunnel and its hydrophobicity. We suggest that these structural and sequential differences influence the ligand-binding abilities of these proteins and provide sand flies with a greater number of YRP paralogs with more nuanced answers to bioamines. All these characteristics allow us to better evaluate these proteins with respect to their potential use as part of anti-Leishmania vaccines or as an antigen to measure host exposure to sand flies.

Sand Waves in Environmental Flows: Insights gained by LES

Science.gov (United States)

Sotiropoulos, Fotis

2014-11-01

In fluvial and coastal environments, sediment transport processes induced by near-bed coherent structures in the turbulent boundary layer developing over a mobile sediment bed result in the formation of dynamically rich sand waves, or bed forms, which grow and migrate continuously. Bed form migration alters streambed roughness and provides the primary mechanism for transporting large amounts of sediment through riverine systems impacting the morphology, streambank stability, and ecology of waterways. I will present recent computational advances, which have enabled coupled, hydro-morphodynamic large-eddy simulation (LES) of turbulent flow in mobile-bed open channels. Numerical simulations: 1) elucidate the role of near-bed sweeps in the turbulent boundary layer as the mechanism for initiating the instability of the initially flat sand bed; 2) show how near-bed processes give rise to aperiodic eruptions of suspended sediment at the free surface; and 3) clarify the mechanism via which sand waves migrate. Furthermore, in agreement with recent experimental observations, the computed spectra of the resolved velocity fluctuations above the bed exhibit a distinct spectral gap whose width increases with distance from the bed. The spectral gap delineates the spectrum of turbulence from that of slowly evolving coherent structures associated with sand wave migration. The talk will also present computational results demonstrating the feasibility of carrying out coupled, hydro-morphodynamic LES of large dunes migrating in meandering streams and rivers with embedded hydraulic structures and discuss future challenges and opportunities. This work was supported by NSF Grants EAR-0120914 and EAR-0738726, and National Cooperative Highway Research Program Grant NCHRP-HR 24-33.

Simulating Sand Behavior through Terrain Subdivision and Particle Refinement

Science.gov (United States)

Clothier, M.

2013-12-01

Advances in computer graphics, GPUs, and parallel processing hardware have provided researchers with new methods to visualize scientific data. In fact, these advances have spurred new research opportunities between computer graphics and other disciplines, such as Earth sciences. Through collaboration, Earth and planetary scientists have benefited by using these advances in hardware technology to process large amounts of data for visualization and analysis. At Oregon State University, we are collaborating with the Oregon Space Grant and IGERT Ecosystem Informatics programs to investigate techniques for simulating the behavior of sand. In addition, we have also been collaborating with the Jet Propulsion Laboratory's DARTS Lab to exchange ideas on our research. The DARTS Lab specializes in the simulation of planetary vehicles, such as the Mars rovers. One aspect of their work is testing these vehicles in a virtual "sand box" to test their performance in different environments. Our research builds upon this idea to create a sand simulation framework to allow for more complex and diverse environments. As a basis for our framework, we have focused on planetary environments, such as the harsh, sandy regions on Mars. To evaluate our framework, we have used simulated planetary vehicles, such as a rover, to gain insight into the performance and interaction between the surface sand and the vehicle. Unfortunately, simulating the vast number of individual sand particles and their interaction with each other has been a computationally complex problem in the past. However, through the use of high-performance computing, we have developed a technique to subdivide physically active terrain regions across a large landscape. To achieve this, we only subdivide terrain regions where sand particles are actively participating with another object or force, such as a rover wheel. This is similar to a Level of Detail (LOD) technique, except that the density of subdivisions are determined by

Effect of Natural Sand Percentages on Fatigue Life of Asphalt Concrete Mixture

Directory of Open Access Journals (Sweden)

Nahla Yassub Ahmed

2016-03-01

Full Text Available The design of a flexible pavement requires the knowledge of the material properties which are characterized by stiffness and fatigue resistance. The fatigue resistance relates the number of load cycles to failure with the strain level applied to the asphalt mixture. The main objective of this research is the evaluation of the fatigue life of asphalt mixtures by using two types of fine aggregate having different percentages. In this study, two types of fine aggregate were used natural sand (desert sand and crushed sand. The crushed sand was replaced by natural sand (desert sand with different percentages (0%, 25%, 75% and 100% by the weight of the sand (passing sieve No.8 and retained on sieve No.200 and one type of binder (40/50 penetration from Al-Daurah refinery. The samples of beams were tested by four point bending beam fatigue test at the control strain mode (250, 500 and 750 microstrain while the loading frequency (5Hz and testing temperature (20oC according to (AASHTO T321. The experimental work showed that fatigue life (Nf and initial flexural stiffness increased when control strain decreased for asphalt mixtures. Acceptable fatigue life at 750 microstrain was obtained with asphalt concrete mixtures containing 100% crushed sand as well as asphalt concrete contained 25% natural sand. The asphalt concrete contained 100% and 75% of natural sand exhibited high fatigue life at low level of microstrain (250. The main conclusion of this study found that best proportion of natural sand to be added to an asphaltic concrete mixture is falling within the range (0% and 25% by weight of fraction (passing No.8 and retained on No.200 sieve .

Performance of a sand filter in removal of micro-algae from seawater in aquaculture production systems.

Science.gov (United States)

Sabiri, N E; Castaing, J B; Massé, A; Jaouen, P

2012-01-01

In this study, a sand filter was used to remove micro-algae from seawater feeding aquaculture ponds. A lab-scale sand filter was used to filter 30,000 cells/mL of Heterocapsa triquetra suspension, a non-toxic micro-alga that has morphological and dimensional (15-20 microm) similarities with Alexandrium sp., one of the smallest toxic micro-algae in seawater. Removal efficiency and capture mechanisms for a fixed superficial velocity (3.5 m/h) were evaluated in relation to size distribution and mean diameter of the sand. Various sands (average diameter ranging between 200 microm and 600 microm) were characterized and used as porous media. The structural parameters of the fixed beds were evaluated for each medium using experimental measurements of pressure drop as a function of superficial velocity over a range of Reynolds numbers covering Darcy's regime and the inertial regime. For a filtration cycle of six hours, the best efficiency (E = 90%) was obtained with the following sand characteristics: sieved sand with a range of grain diameter of 100 and 300 microm and a mean grain diameter equal to 256 microm. Results obtained show the influence of the size distribution of sand on the quality of retention of the micro-algae studied.

Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

International Nuclear Information System (INIS)

Hansen, W.R.; Rodgers, J.C.

1985-06-01

Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs

Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

Energy Technology Data Exchange (ETDEWEB)

Hansen, W.R.; Rodgers, J.C.

1985-06-01

Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs.

High-resolution sequence stratigraphic correlation of the braided river and vertical distribution characteristics of sand body-Take upper member of saihan formation of lower cretaceous in Bayanwula deposit, for instance

International Nuclear Information System (INIS)

Dai Mingjian; Peng Yunbiao; Yang Jianxin; Shen Kefeng

2014-01-01

In recent years, the high-resolution sequence stratigraphy of which reference surface is base level cycle get rapid development. Its biggest advantage is the ability to apply to the continental sedimentary basins controlled by multiple factors, especially applied to the thin layer contrast of the paleochannel sandstone type uranium reservoir. This paper, by using drill core and logging data, has made the high resolution sequence stratigraphy studies on braided river uranium reservoir of Upper Member of Saihan Formation of Lower Cretaceous (Kls2) in Bayanwula deposit and identified the base level cycle interface. The study interval is divided into one long-term cycle and seven mid-term base level cycle, and high-resolution time stratigraphic framework of the deposit is established. Depth analysis is taken for the relationship between the braided river sand body and base level cycles. And the position, distribution, and genesis in vertical of the braided river sand body are discussed in detail. Ore body is mainly hosted in edge of braided bar sand body, which formed in the low accommodation space, and braided channel and the braided bar interchange. So uranium enriched in the mid-term base level cycle MSC2-MSC5 in the study area. (authors)

Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

Directory of Open Access Journals (Sweden)

Qinli Zhang

2016-12-01

Full Text Available Aeolian sand, tailings, and #32.5 Portland cement were used to produce backfilling aggregate, and physicochemical evaluations and proportioning tests were conducted. It is revealed that a mixture of aeolian sand and tailings can be used as a backfilling aggregate for the complementarities of their physicochemical properties; e.g., high Al2O3 content in the aeolian sand and CaO content in the tailings, coarse particles of aeolian sand and fine particles of tailings, etc. In addition, the optimal backfilling aggregate was shown to have a mass fraction of 72%–74%, a cement–sand ratio of 1:8, and an aeolian sand proportion of 25%. Furthermore, viscometer tests were used to analyze the rheological characteristics, and the slurry in these optimized proportions exhibited shear thinning phenomena with an initial yield stress, which belongs to paste-like—a cemented backfilling slurry with a higher mass fraction than a two-phase flow and better flowability than a paste slurry. Finally, the application of this backfilling technology shows that it can not only realize safe mining, but also bring huge economic benefits, and has some constructive guidance for environmental protection.

Field test on sand compaction pile method with copper slag sand; Dosuisai slag wo mochiita SCP koho no shiken seko

Energy Technology Data Exchange (ETDEWEB)

Minami, K.; Matsui, H.; Naruse, E.; Kitazume, M. [Port and Harbour Research Inst., Kanagawa (Japan)

1997-09-20

This paper describes the sand compaction pile (SCP) method using copper slag sand. The SCP method is a method by which sand compaction piles are constructed in the ground, and improvement can be obtained in a short period. This method has been widely used even in the port areas for enhancing the bearing power of soft clay ground and the lateral resistance of sheet pile. A great deal of sand is required as a material. The sand requires high permeability, proper size distribution with less fine particle fraction content, easy compaction property with enough strength, and easy discharging property from the casing of construction machines as required properties. Recently, it becomes hard to secure proper sand materials. The copper slag sand is obtained from refining process of copper as a by-product which is quenched in water flow and crushed in water. The copper slag sand has higher particle density than that of sand, excellent permeability, and similar size distribution to that of sand. From compaction drainage triaxial compression test and permeability test, it was found that the mechanical properties of copper slag sand did not change by the crushing of grains with keeping excellent permeability. Through the test construction, applicability of the copper slag sand to the SCP method could be confirmed as an alternate material of sand. 17 refs., 9 figs., 4 tabs.

Elemental Analysis and Radionuclides Monitoring of Beach Black Sand at North of Nile Delta, Egypt

Science.gov (United States)

Ali, Abdallah; Fayez-Hassan, M.; Mansour, N. A.; Mubarak, Fawzia; Ahmed, Talaat Salah; Hassanin, W. F.

2017-12-01

A study was carried out on the concentrations of elements presented in beach black sand samples collected from North of Nile Delta along Mediterranean Coast using instrumental neutron activation analysis (INAA) as an effective analysis technique, especially for monitoring elements. The Egyptian Research Reactor-2 (ETRR-2) as a facility was used for the samples irradiation in the thermal mode of a neutron flux 3 × 1011 n/cm2 s. Natural radioactive elements, rare element and heavy elements as U, Th, La, Lu, Sm, Ce, Nd, Eu, Gd, Sc, Tb, Yb, As, Br, Na, Sb, Ba, Co, Cr, Fe, Hg, Hf, Sr, Ta, Zn and Zr were determined with concentrations average values 16.3, 78.8, 195.4, 3.3, 31.3, 445.1, 223, 7.2, 8.5, 97.1, 3.6, 31.1, 6.1, 24.5, 27,236.8, 1.42, 1327.7, 81.1, 1814.3, 263,735, 0.1, 237.3, 878.7, 20.8, 671.1 and 6225.9 (mg/kg), respectively. The experimental data results were analyzed to evidence any correlations of these elements as well as to know the geological formation in the study area. The elements concentrations in the black sand samples were found higher than the world average crustal soil values except for As and Sb. Results were compared with similar beach black sand in previous studies. The enrichment factor (EF) and geoaccumulation index (I geo) for heavy elements were presented to evaluate the contamination rate. We can summarize that exposure for natural radionuclides (U and Th) in this area were still within the acceptable limits due to little time of exposure. Therefore, the black sands from North of Nile Delta are not recommended for use in building constructions due to high radioactive doses.

Galveston Island, Texas, Sand Management Strategies

Science.gov (United States)

2016-07-01

billion m3 of beach quality sand . However, Texas projects to date have not utilized these sources because of transportation costs. The lack of nearby...estimate that the San Luis Pass flood shoal contains approximately 11.8 million yd3 of beach quality sand . However, it is expected that if permits...a source of beach- quality sand . 2. Sand could be intercepted before it reaches the present dry beach. ERDC/CHL TR-16-13 55 3. The volume of

Geothermal resources: Frio Formation, Middle Texas Gulf Coast. Geological circular 75-8

Energy Technology Data Exchange (ETDEWEB)

Bebout, D.G.; Agagu, O.K.; Dorfman, M.H.

1975-01-01

Regional sand distribution of the Frio Formation is determined; depositional environments are identified; and the geopressured zone and its relationship to sand/shale distribution, growth faults, and fluid temperatures in the Middle Texas Gulf Coast are delineated. (MHR)

Mineral Resource Assessment of Marine Sand Resources in Cape- and Ridge-Associated Marine Sand Deposits in Three Tracts, New York and New Jersey, United States Atlantic Continental Shelf

Science.gov (United States)

Bliss, James D.; Williams, S. Jeffress; Arsenault, Matthew A.

2009-01-01

Demand is growing in the United States and worldwide for information about the geology of offshore continental shelf regions, the character of the seafloor, and sediments comprising the seafloor and subbottom. Interest in locating sand bodies or high quality deposits that have potential as sources for beach nourishment and ecosystem restoration is especially great in some regions of the country. The Atlantic coast, particularly New York and New Jersey, has been the focus of these studies for the past 40 years with widely varying results. This study is the first attempt at applying probability statistics to modeling Holocene-age cape-and ridge-associated sand deposits and thus focuses on distinct sand body morphology. This modeling technique may have application for other continental shelf regions that have similar geologic character and late Quaternary sea-level transgression history. An estimated volume of 3.9 billion m3 of marine sand resources is predicted in the cape-and ridge-associated marine sand deposits in three representative regions or tracts on the continental shelf offshore of New York and New Jersey. These estimates are taken from probabilistic distributions of sand resources and are produced using deposit models and Monte Carlo Simulation (MCS) techniques. The estimated sand resources presented here are for only three tracts as described below and for Holocene age sand resources contained in cape-and ridge-associated marine sand deposit types within this area. Other areas may qualify as tracts for this deposit type and other deposit types and geologic ages (for example, paleo-stream channels, blanket and outwash deposits, ebb-tide shoals, and lower sea level-stand deltas), which are present on the New Jersey and New York continental shelf area but are not delineated and modeled in this initial evaluation. Admittedly, only a portion of these probable sand resources will ultimately be available and suitable for production, dependent largely on

Pre injection characterisation and evaluation of CO{sub 2} sequestration potential in the Haizume formation, Niigata basin, Japan; Caracterisation avant injection et evaluation du potentiel de sequestration de CO{sub 2} dans la formation de Haizume, bassin de Niigata, Japon. Modelisation geochimique des interactions eau-mineraux-CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Zwingmann, N. [CSIRO Petroleum, ARRC, Bentley, WA (Australia); Mito, S.; Sorai, M.; Ohsumi, T. [RITE, Kyoto (Japan); Zwingmann, N. [Western, Univ. (Australia); Sorai, M. [Mitsubishi Research Institute, Inc. (Japan)

2005-03-15

The Research Institute of Innovative Technology for the Earth (RITE) is carrying out a small-scale CO{sub 2} injection field experiment to investigate the feasibility of geological sequestration of CO{sub 2} greenhouse gas in the south-west of Nagaoka City, Niigata Prefecture, Japan. Prior to the injection geochemical reactions caused by CO{sub 2} injections were investigated using the geochemical modelling code (EQ3/6). The injection formation is the sedimentary marine Haizume Formation (Pleistocene) in the Uonuma Group, which is covered by a mud-stone seal. The formation is mainly composed of quartz, plagioclase, feldspar, pyroxene, and clays (smectite, chlorite). The sandstone shows minor consolidation and grain size is medium to coarse sand. The total dissolved solid (TDS) of the formation water is approximately 6100 mg/l and the water contains a high Ca{sup 2+} ({>=} 20% of Na{sup +} concentration). The geochemical model was used for an initial adjustment of the formation water chemistry to the formation conditions and a modelling of the formation water-mineral-CO{sub 2} reactions. The modelling results showed a high reactivity of the minerals in the CO{sub 2} rich environment and high mineral conversion rate within the formation. At the final state, approximately 23 mol of CO{sub 2} were taken into 1 kg of formation water and more than 90% of this was stored within carbonate minerals. In this simulation, some uncertainty is associated with the time scale and a more detailed investigation is planned and will address accurate evaluation. (authors)

Study of Slow Sand Filtration in Removing Total Coliforms and E.Coli

Directory of Open Access Journals (Sweden)

Ekha Yogafanny

2015-08-01

Full Text Available This study was aimed to evaluate the performance of SSF in removing bacteria (Total Coliforms and E. Coli in regard to grain size distribution and grain shape intermittently. Two methodological approaches used in this reasearch were literature review and laboratory work. Bacteria removal was analyzed considering two different filter media (Rhine sand-spherical shape and Lava sand-angular shape with three different grain size distributions. The best performance was attained by filter column F4 which consisted of Lava sand and had the configuration C2 (d10 = 0.07 mm; Cu = 4.2. This filter column achieved 4.7log-units removal of Total Coliforms and 5.0log-units removal of E. coli. The results show that a smaller grain size and an angular shape of sand grain lead to an increase in bacteria removal.

Japan's involvement in oil sands development

International Nuclear Information System (INIS)

Sugiura, T.

1994-01-01

According to Japanese national policy, exploration and development by Japanese companies in overseas countries are promoted in order to ensure stable oil supplies. Japan Canada Oil Sands Limited (JACOS), part of the JAPEX group, was established during the 1978 world oil crisis to explore and develop Canadian oil sand resources in accordance with Japan's national policy. The JAPEX group, including JACOS, has invested $123 million in oil sands projects in Alberta. JAPEX's first involvement in oil sands was in the Primrose Project operated by Norcen in the Cold Lake area. Five years of cyclic steam stimulation pilot tests did not produce sufficiently good results to justify further operation. The second involvement was the PCEJ Project, a joint effort by four companies that are participating in a bitumen recovery test project in the Athabasca Deposit. JACOS holds 2,452 km 2 of oil sands leases in Alberta. Tests conducted since 1978 in the PCEJ Project include multiwell steam injection pilot tests, some of which showed promise. JACOS is also participating in steam assisted gravity drainage projects and in federal/provincial research programs. Obstacles identified in developing Alberta oil sands are the lack of a bitumen pipeline to Edmonton and the insufficient length of oil sands leases (currently 10 years), given the difficulties of oil sand development. 10 figs

MouldingSandDB – a modern database storing moulding sands properties research results

Directory of Open Access Journals (Sweden)

J. Jakubski

2011-01-01

Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

Often overlooked: formative evaluation in the development of ScienceComics

Directory of Open Access Journals (Sweden)

E. Weitkamp

2009-10-01

Full Text Available Formative evaluation should play a key role in the development of a science communication project or initiative. Such research is vital to understanding the needs and interests of the audience or participants; meeting these needs and interests helps ensure the project’s success. However, there can be a temptation to plough ahead without undertaking adequate formative evaluation. Using ScienceComics (www.sciencecomics.uwe.ac.uk as a case study, this article explores both the challenges and benefits of using formative evaluation to guide project development. It focuses on the actors involved in the formative stages and the impacts these actors had on the final outputs. This evidence is used to develop practical guidance on integrating formative evaluation right from the start.

A study of global sand seas

Science.gov (United States)

McKee, Edwin D.

1979-01-01

The birth of the idea that led to this publication on "Global Sand Seas" dates back to the late 1920's. At that time I was engaged in a study of the Coconino Sandstone of Arizona's Grand Canyon. Considerable controversy existed then as to whether this sandstone was a subaqueous deposit or was composed of wind-formed dunes. It became apparent that definitive literature was sparse or lacking on types of dunes, global distribution of these types, the mechanics of their development, the precise nature of their internal structure of cross-stratificiation, and the relation of wind systems to these sand forms. Especially lacking were data on criteria that could confidently be used in the recognition of ancient dunes. The common denominator in this publication is eolian sand bodies. Although the book is concerned primarily with desert sand seas, the subject matter is not restricted to deserts; it includes many references to deposits of coastal sand and to sand bodies in humid climates. Nor does the book deal exclusively with dunes, which, according to most definitions, involve mounds or hills. Many references are made to sand sheets, sand stringers, and other types of sand deposits that have no prominent topographic expression. All sand bodies accumulated by the action of wind are discussed. Chapters A-J of this publication are primarily topical. Chapters cover the grain texture, the color, and the structure of modern dunes and other eolian sands. Special treatment is given to the relation of wind data to dune interpretation, the evolution of form in current-deposited sand bodies as determined from experimental studies, and the discriminant analysis technique for differentiating between coastal and inland desert sands. This topical part of the publication also includes an analysis of criteria used in ancient deposits to interpret their eolian genesis and a consideration of economic application of the principles described, including a discussion of potentials and problems

3D Finite Element Analysis of PWA-Oil Sand Terrain System Interaction

Directory of Open Access Journals (Sweden)

Y. Li

2012-01-01

Full Text Available A simulator for analyzing the interaction between the oil sand terrain and a pipe wagon articulating (PWA system has been developed in this paper. An elastic-plastic oil sand model was built based on the finite element analysis (FEA method and von Mises yield criterion using the Algor mechanical event simulation (MES software. The three-dimensional (3D distribution of the stress, strain, nodal displacement, and deformed shape of the oil sands was animated at an environmental temperature of 25°C. The 3D behavior of the oil sand terrain was investigated with different loading conditions. The effect of the load and contact area on the stress and nodal displacement was analyzed, respectively. The results indicate that both the max stress and max nodal displacement increase with the load varying from 0 to 3.6+7 N and decrease with the contact area varying from 2 to 10 m2. The method presented in this paper forms the basis for evaluating the bearing capacity of oil sand ground.

Proceedings of the oil sands and heavy oil technologies conference and exhibition

International Nuclear Information System (INIS)

2009-01-01

This conference provided a forum for oil sands industry leaders to review the current and future state of technology in this frontier environment. Presentations were delivered by key personnel involved in groundbreaking projects with a renewed focus on oil sands technology and equipment, viewed from the strategic level with case studies and reports on application technologies designed to optimize oil sands operations. The presentations addressed a wide range of issues related to the environmental impacts of oil sands processing facilities, including innovative water and wastewater solutions for heavy oil producers for bitumen mining, in-situ and upgrading facilities. New advances in sulphur treatment technologies were highlighted along with technologies designed to increase the energy efficiency and energy consumption rates of upgrader and processing facilities. Advances in carbon dioxide (CO 2 ) capture and storage systems were also discussed along with geopolitical and economic evaluations of the future of the oil sands industry. The conference featured 59 presentations, of which 48 have been catalogued separately for inclusion in this database. refs., tabs., figs

Numerical simulation of wind-sand movement in the reversed flow region of a sand dune with a bridge built downstream.

Science.gov (United States)

He, Wei; Huang, Ning; Xu, Bin; Wang, Wenbo

2018-04-23

A bridge built inside the reversed flow region of a sand dune will change the characteristics of wind-sand movement in this region. The Reynolds-averaged Navier-Stokes simulation and discrete particle tracing are used to simulate the wind-sand movement around a sand dune with a bridge built inside the reversed region. Three cases with different bridge positions are studied. The results show that 1) compared with the isolated dune case, a tall bridge built at the leeward toe leads to an increase in the deposition rate on the leeward slope and a longer reversed flow region downstream of the sand dune; meanwhile, the high speed of crosswind on the bridge indicates that some measures should be taken to protect trains from strong crosswind; 2) a low bridge at the leeward toe has little effect on the sand deposition and reversed flow region of the dune; however, low sand transport rate and crosswind speed on the bridge show that anti-crosswind/sand measures should be taken according to the actual situation and 3) a low bridge on the leeward slope has little effect on the length of reversed flow region, however, high crosswind speed and sand flux on the bridge reveal the need of anti-crosswind/sand measures on the bridge. Moreover, the bridges in the reversed flow region increase the sand flux near the leeward crest; as a result, the moving patterns of the sand dune are changed.

Morphological characterization of ceramic fillers made from Indonesian natural sand as restorative dental materials

Science.gov (United States)

Karlina, E.; Susra, S.; Fatmala, Y.; Hartoyo, H. M.; Takarini, V.; Usri, K.; Febrida, R.; Djustiana, N.; Panatarani, C.; Joni, I. M.

2018-02-01

Dental composite as restorative dental materials can be reinforced using ceramic fillers. Homogeneous distribution of filler particles shall improve its mechanical properties. This paper presents the results of the preliminary study on the ZrO2-Al2O3-SiO2 ceramic fillers made from Indonesian natural sand that can increase the mechanical properties of dental composite. The synthesis was done using zirconium silicate sand (ZrSiO4) and aluminium oxide (Al2O3) precursors, which dissolved together with 70:30 weight ratios. Two types of sand were used: (1) manufactured sand (mesh #80) and (2) natural sand (mesh #400). The samples then heated in the furnace at 1100 °C for 8 hours. The morphological characterization was then evaluated using JEOL Scanning Electron Microscope (SEM) for the surface structure that analyze particles size and distribution. Ceramic fillers made from natural sand is homogenous, well distributed with average particle size of 5-10 µm. Comparably, ceramic filler made from the manufactured sand is heterogeneous, poorly distributed and appear as agglomerates with average particle size are 30-50 µm. The results suggest that ceramic fillers made from natural sand demonstrate better character to represent as a functional restorative dental material.

Harding - a field case study: Sand control strategy for ultra-high productivity and injectivity wells

Energy Technology Data Exchange (ETDEWEB)

McKay, G.; Bennett, C.; Price-Smith, C.; Dowell, S.; McLellan, W. [British Petroleum (United Kingdom)

1998-12-31

The strategy adopted and the factors considered in the development of the sandface completion design for Phase One of the Harding Field in the unconsolidated Balder Massive Sand in the U.K. Sector of the North Sea is described. The field development utilizes a TPG 500 Jack-up Drilling and Production Unit in conjunction with a concrete gravity base tank (GBT). The first phase of the development involved drilling and completing horizontal wells sand-free, ultra-high production (over 30,000 BOPD/well, with PI in excess of 1,000 bbl/day/psi). The experiences showed that pre-packed screens can be successfully utilized to provide lasting sand control with high rate of production in clean homogenous sandstones, and that testing for fluid compatibility, formation damage, screen plugging, corrosion and erosion potential are essential pre-requisites in determining the optimal solution in any well with sand production potential.The experiences gained in Phase One have contributed to design enhancements for Phase Two of the project which include extended reach horizontal wells to neighbouring satellite pools. 3 refs., 1 tab., 8 figs.

Use of coal ash in production of concrete containing contaminated sand

International Nuclear Information System (INIS)

Ezeldin, A.S.

1991-01-01

There are between 2 to 3.5 million underground storage tanks located throughout the nation. Most of these tanks, which store oils and gasolines, are leaking making them one of the primary sources of soil contamination. Adding coal ash or cement to contaminated soil has been used to obtain stationary and inert wastecrete. By using this procedure, stabilization (limiting the solubility and mobility of the contaminants) and solidification (producing a solid waste block) of contaminated soils are successfully achieved. This paper investigates another re-use option of coal ash and contaminated soils. An experimental study evaluating the effectiveness of using coal ash with oil contaminated sand in concrete production is presented. A control mix made of clean sand was designed to yield 500 psi of compressive strength. Sand, artificially contaminated with 3% by weight of motor oil, was used as clean sand replacement. Six concrete mixtures were tested in compression and flexure. The six mixtures were obtained by increasing the ratio of contaminated sand to clean sand, namely; 10%, 20% and 40% and by introducing coal ash to the concrete mixture, namely; 20% of the cement weight. The test results indicate that the inclusion of oil contaminated sand in concrete reduces the compressive and flexural strengths. However, this decrease in strength is compensated by introducing coal ash in the mixture. Regaining that strength offers the possibility of using such concrete as a construction material in special structural applications. More research is required to establish better understanding of that composite and suggest feasible applications

Test work of sand compaction pile method on coal ash soil foundation. Sekitanbai jiban ni okeru sand compaction pile koho no shiken seko

Energy Technology Data Exchange (ETDEWEB)

Goto, K.; Maeda, S.; Shibata, T. (The Kansai Electric Power Co. Inc., Osaka (Japan))

1992-01-25

As an electric power supply source after the 1990 {prime}s, Nos. 5 and 6 units are additionally being constructed by Kansai Electric Power in its Himeji Power Station No.1 which is an exclusively LNG burning power station. The additional construction site of those units is of soil foundation reclaimed with coal ash which was used residual product in the existing No.1 through No.4 units. As a result of soil foundation survey, the coal ash layer and sand layer were known to be of material to be possibly liquidized at the time of earthquake. As measures against the liquidization, application was basically made of a sand compaction pile (SCP) method which is economical and abundant in record. However, that method was so short of record in the coal ash layer that its evaluation was difficult in soil reforming effect. Therefore, its applicability was evaluated by a work test on the site, which resulted in a confirmation that the coal ash as well as the sand can be sufficiently reformed by the SCP method. Started in September, 1991, the additional construction of Nos. 5 and 6 units in Himeji Power Station No.1 uses a 1.5m pitch SCP method to reform the soil foundation. 3 refs., 10 figs., 1 tab.

The Carolina Sandhills: Quaternary eolian sand sheets and dunes along the updip margin of the Atlantic Coastal Plain province, southeastern United States

Science.gov (United States)

Swezey, Christopher; Fitzwater, Bradley A.; Whittecar, G. Richard; Mahan, Shannon; Garrity, Christopher P.; Aleman Gonzalez, Wilma B.; Dobbs, Kerby M.

2016-01-01

The Carolina Sandhills is a physiographic region of the Atlantic Coastal Plain province in the southeastern United States. In Chesterfield County (South Carolina), the surficial sand of this region is the Pinehurst Formation, which is interpreted as eolian sand derived from the underlying Cretaceous Middendorf Formation. This sand has yielded three clusters of optically stimulated luminescence ages: (1) 75 to 37 thousand years ago (ka), coincident with growth of the Laurentide Ice Sheet; (2) 28 to 18 ka, coincident with the last glacial maximum (LGM); and (3) 12 to 6 ka, mostly coincident with the Younger Dryas through final collapse of the Laurentide Ice Sheet. Relict dune morphologies are consistent with winds from the west or northwest, coincident with modern and inferred LGM January wind directions. Sand sheets are more common than dunes because of effects of coarse grain size (mean range: 0.35–0.59 mm) and vegetation. The coarse grain size would have required LGM wind velocities of at least 4–6 m/sec, accounting for effects of colder air temperatures on eolian sand transport. The eolian interpretation of the Carolina Sandhills is consistent with other evidence for eolian activity in the southeastern United States during the last glaciation.

In situ radionuclide migration studies in a shallow sand aquifer. Part. 1. Part. 2: appendices

International Nuclear Information System (INIS)

Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

1986-01-01

As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been constructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl) and iodine-131 (as NaI). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjunction with 131 I. The principal research objectives of the programme are as follows: (1) To undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) To identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) To obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. Part 2 of this report contains the following appendices: (1) Calculation of sorption parameters. (2) A low-cost manifold system for use with multi-level samplers. (3) Radioactivity curves for 131 I and 85 Sr. (4) Results of particle size analysis for sand aquifers

Construction of a test embankment using a sand-tire shred mixture as fill material.

Science.gov (United States)

Yoon, Sungmin; Prezzi, Monica; Siddiki, Nayyar Zia; Kim, Bumjoo

2006-01-01

Use of tire shreds in construction projects, such as highway embankments, is becoming an accepted way of beneficially recycling scrap tires. However, in the last decade there was a decline in the use of pure tire shreds as fill materials in embankment construction, as they are susceptible to fire hazards due to the development of exothermic reactions. Tire shred-sand mixtures, on the other hand, were found to be effective in inhibiting exothermic reactions. When compared with pure tire shreds, tire shred-sand mixtures are less compressible and have higher shear strength. However, the literature contains limited information on the use of tire shred-soil mixtures as a fill material. The objectives of this paper are to discuss and evaluate the feasibility of using tire shred-sand mixtures as a fill material in embankment construction. A test embankment constructed using a 50/50 mixture, by volume, of tire shreds and sand was instrumented and monitored to: (a) determine total and differential settlements; (b) evaluate the environmental impact of the embankment construction on the groundwater quality due to leaching of fill material; and (c) study the temperature variation inside the embankment. The findings in this research indicate that mixtures of tire shreds and sand are viable materials for embankment construction.

Sand dune tracking from satellite laser altimetry

Science.gov (United States)

Dabboor, Mohammed

Substantial problems arise from sand movement in arid and semi-arid countries. Sand poses a threat to infrastructure, agricultural and urban areas. These issues are caused by the encroachment of sand on roads and railway tracks, farmland, towns and villages, and airports, to name a few. Sand movement highly depends on geomorphology including vegetation cover, shape and height of the terrain, and grain size of the sand. However, wind direction and speed are the most important factors that affect efficient sand movement. The direction of the movement depends on the main direction of the wind, but it has been shown that a minimum wind speed is required, e.g. wind gusts, to initiate sand transport. This fact prevents a simple calculation of sand transport from conventional wind data as wind records rarely contain sub-minute intervals masking out any wind gusts. An alternative of predicting sand transport is the direct observation of sand advance by in situ measurements or via satellite. Until recently, satellite imagery was the only means to compare dune shape and position for predicting dune migration over several years. In 2003, the NASA laser altimetry mission ICESat became operational and monitors elevations over all surface types including sand dunes with an accuracy of about 10-20 cm. In this study, ICESat observations from repeat tracks (tracks overlapping eachother within 50 m) are used to derive sand dune advance and direction. The method employs a correlation of the elevation profiles over several dunes and was sucessfully validated with synthetic data. The accuracy of this method is 5 meters of dune advance. One of the most active areas exhibiting sand and dune movement is the area of the Arabian Peninsula. Approximately one-third of the Arabian Peninsula is covered by sand dunes. Different wind regimes (Shamal, Kaus) cause sand dune movement in the selected study area in the eastern part of the Arabian Peninsula between 20-25 degrees North and 45-55 degrees

Maturation, fecundity, and intertidal spawning of Pacific sand lance in the northern Gulf of Alaska

Science.gov (United States)

Robards, Martin D.; Piatt, John F.; Rose, G.A.

1999-01-01

Pacific sand lance Ammodytes hexapterus in Kachemak Bay, Alaska, showed no sexual dimorphism in length-to-weight (gonad-free) ratio or length-at-age relationship. Most matured in their second year, males earlier in the season than females, but females (31%) attained a higher gonadosomatic index than males (21%). Sand lance spawned intertidally once each year in late September and October on fine gravel or sandy beaches soon after the seasonal peak in water temperatures. Sand lance in Cook Inlet and Prince William Sound displayed similar maturation schedules. Schools were dominated 2: 1 by males as they approached the intertidal zone at a site where spawning has taken place for decades. Sand lance spawned vigorously in dense formations, leaving scoured pits in beach sediments. Fecundity of females (93–199 mm) was proportional to length, ranging from 1468 to 16 081 ova per female. About half of the overall spawning school fecundity was derived from age group 1 females (55% of the school by number). Spawned eggs were 1·02 mm in diameter, demersal, slightly adhesive, and deposited in the intertidal just below the waterline. Sand lance embryos developed over 67 days through periods of intertidal exposure and sub-freezing air temperatures.

Royal Society of Canada expert panel report : environmental and health impacts of Canada's oil sands industry

International Nuclear Information System (INIS)

Gosselin, P.; Hrudey, S.E.; Naeth, M.A.; Plourde, A.; Therrien, R.; Laval Univ., Quebec City, PQ; Van Der Kraak, G.; Guelph Univ., ON; Xu, Z.

2010-12-01

This expert panel report was commissioned by the Royal Society of Canada to provide a comprehensive evidence-based assessment of the environmental and health impacts of Canada's oil sands industry. The report evaluated the feasibility of land reclamation and the impacts of oil sands contaminants on downstream residents. Health impacts on residents living in the Regional Municipality of Wood Buffalo were assessed, and the impacts on regional water supplies were evaluated. Regional water and ground water quantities were examined, and issues related to tailing pond operations and reclamation were examined. Ambient air quality impacts were assessed, as well as potential impacts of the oil sands industry on greenhouse gas (GHG) emissions. The environmental regulatory performance of operators in the industry was also evaluated. A summary of economic and policy issues related to the industry was also provided. The study identified major gaps in the process of assessment, prevention, and mitigation of the health impacts of oil sands exploitation, as as major indirect health impacts linked to past exploitation activities. 672 refs., 11 tabs., 11 figs. 10 appendices.

Magnetic Characterization of Sand and Boulder Samples from Citarum River and Their Origin

Directory of Open Access Journals (Sweden)

Sudarningsih

2017-09-01

Full Text Available The Citarum River is a nationally strategic river located near Bandung, the capital city of West Java Province. The feasibility of using magnetic methods for monitoring pollution level is currently being tested in the river. Due to its location in a volcanic area, the sediments from the river are expected to be highly magnetic. In this study, sand and boulder samples from Balekambang, a relatively pristine upstream area of the river, were subjected to magnetic and geochemical characterizations to establish the baseline for unpolluted sediments. Such baseline is important for future magnetic monitoring of sediments in the river. The mass-specific magnetic susceptibility of boulder samples was found to be varied from 819.2 to 2340.5 × 10-8m3 kg-1 while that of sand samples varied from 2293.9 to 3845.3 × 10-8m3 kg-1. These high magnetic susceptibility values infer that river sediments are highly magnetic even before being contaminated by industrial and household wastes. The predominant magnetic mineral in sand samples was multi-domain magnetite while that in boulder samples was single to pseudo-single domain magnetite. These differences were supported by the results from petrographic and XRF analyses, implying that the sand and boulder samples originated from different geological formations.

FeS-coated sand for removal of arsenic(III) under anaerobic conditions in permeable reactive barriers

Science.gov (United States)

Han, Y.-S.; Gallegos, T.J.; Demond, A.H.; Hayes, K.F.

2011-01-01

Iron sulfide (as mackinawite, FeS) has shown considerable promise as a material for the removal of As(III) under anoxic conditions. However, as a nanoparticulate material, synthetic FeS is not suitable for use in conventional permeable reactive barriers (PRBs). This study developed a methodology for coating a natural silica sand to produce a material of an appropriate diameter for a PRB. Aging time, pH, rinse time, and volume ratios were varied, with a maximum coating of 4.0 mg FeS/g sand achieved using a pH 5.5 solution at a 1:4 volume ratio (sand: 2 g/L FeS suspension), three days of aging and no rinsing. Comparing the mass deposited on the sand, which had a natural iron-oxide coating, with and without chemical washing showed that the iron-oxide coating was essential to the formation of a stable FeS coating. Scanning electron microscopy images of the FeS-coated sand showed a patchwise FeS surface coating. X-ray photoelectron spectroscopy showed a partial oxidation of the Fe(II) to Fe(III) during the coating process, and some oxidation of S to polysulfides. Removal of As(III) by FeS-coated sand was 30% of that by nanoparticulate FeS at pH 5 and 7. At pH 9, the relative removal was 400%, perhaps due to the natural oxide coating of the sand or a secondary mineral phase from mackinawite oxidation. Although many studies have investigated the coating of sands with iron oxides, little prior work reports coating with iron sulfides. The results suggest that a suitable PRB material for the removal of As(III) under anoxic conditions can be produced through the deposition of a coating of FeS onto natural silica sand with an iron-oxide coating. ?? 2010 Elsevier Ltd.

Ecotoxicological impacts of effluents generated by oil sands bitumen extraction and oil sands lixiviation on Pseudokirchneriella subcapitata

Energy Technology Data Exchange (ETDEWEB)

Debenest, T., E-mail: tdebenest@yahoo.fr [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Turcotte, P. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagne, F., E-mail: francois.gagne@ec.gc.ca [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada); Gagnon, C.; Blaise, C. [Environment Canada, Fluvial Ecosystem Research, 105 McGill Street, 7 floor, Montreal, Quebec, H2Y 2E7 (Canada)

2012-05-15

The exploitation of Athabasca oil sands deposits in northern Alberta has known an intense development in recent years. This development has raised concern about the ecotoxicological risk of such industrial activities adjacent to the Athabasca River. Indeed, bitumen extraction generated large amounts of oil sands process-affected water (OSPW) which are discharged in tailing ponds in the Athabasca River watershed. This study sought to evaluate and compare the toxicity of OSPW and oil sands lixiviate water (OSLW) with a baseline (oil sands exposed to water; OSW) on a microalgae, Pseudokirchneriella subcapitata, at different concentrations (1.9, 5.5, 12.25, 25 and 37.5%, v/v). Chemical analyses of water-soluble contaminants showed that OSPW and OSLW were enriched in different elements such as vanadium (enrichment factor, EF = 66 and 12, respectively), aluminum (EF = 64 and 15, respectively), iron (EF = 52.5 and 17.1, respectively) and chromium (39 and 10, respectively). The toxicity of OSPW on cells with optimal intracellular esterase activity and chlorophyll autofluorescence (viable cells) (72 h-IC 50% < 1.9%) was 20 times higher than the one of OSW (72 h-IC 50% > 37.5%, v/v). OSLW was 4.4 times less toxic (IC 50% = 8.5%, v/v) than OSPW and 4.5 times more toxic than OSW. The inhibition of viable cell growth was significantly and highly correlated (<-0.7) with the increase of arsenic, beryllium, chromium, copper, lead, molybdenum and vanadium concentrations. The specific photosynthetic responses studied with JIP-test (rapid and polyphasic chlorophyll a fluorescence emission) showed a stimulation of the different functional parameters (efficiency of PSII to absorb energy from photons, size of effective PSII antenna and vitality of photosynthetic apparatus for energy conversion) in cultures exposed to OSPW and OSLW. To our knowledge, our study highlights the first evidence of physiological effects of OSPW and OSLW on microalgae.

Summary of the engineering assessment of radioactive sands and residues, Lowman Site, Lowman, Idaho

International Nuclear Information System (INIS)

1981-09-01

Ford, Bacon and Davis Utah Inc. has reevaluated the Lowman site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive sands and residues at Lowman, Idaho. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of radioactive sands and residues and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 191,000 tons of radioactive sands, residues, and contaminated soils at the Lowman site constitutes the most significant environmental impact, although windblown radioactive sands and external gamma radiation also are factors

bentonite-sand mixture as new backfill/buffer material

International Nuclear Information System (INIS)

Cui Suli; Liu Jisheng; Zhang Huyuan; Liang Jian

2008-01-01

The mixture of bentonite and quartz sand is suggested as a new backfill/buffer material for geological disposal of HLW. To improve the further design of underground laboratory and in-situ industrial construction test, the optimization of sand addition to bentonite is focused at present research stage. Based on summarizing the research results abroad, laboratory tests were conducted on the mixture of GMZ001 bentonite and quartz sand, such as compaction test and swelling tests etc. Test data shows that GMZ bentonite-sand mixture exhibits a favorite compaction with a 30% sand addition, a highest swelling pressure with a 20% sand addition, and a decreasing plasticity with increases in sand addition and pore liquid concentration. (authors)

A Laboratory Experiment on the Evolution of a Sand Gravel Reach Under a Lack of Sediment Supply

Science.gov (United States)

Orru, C.; Chavarrias, V.; Ferrara, V.; Blom, A.

2014-12-01

A flume experiment was conducted to examine the evolution of a sand-gravel reach under a lack of sediment supply. The experimental data are used to validate a numerical sand-gravel model. A bed composed of a bi-modal sediment mixture is installed with a uniform slope and an imposed gradual fining pattern. Initially, the sand fraction gradually increases in streamwise direction until the bed is fully composed of sand. The water discharge and downstream water level were constant, and the sediment feed rate was equal to zero. The experiment was dominated by bed load, partial transport, and a subcritical flow regime was imposed. The flow rate was such that only sand was mobile (partial transport), which led to a coarsening over the upstream reach and a gradual reduction of the sediment transport rate during the experiment. New equipment was used to measure the evolution of the grain size distribution of the bed surface during the experiment over the entire flume using image analysis. In the upstream reach we observed a gradual coarsening over time and the formation of an armour layer, which resulted in a more abrupt transition in grain size of the bed surface. Bed degradation increased in streamwise direction. This is due to the initial streamwise increase in the availability of sand in the bed. The different volume fraction content of sand in the bed allowed for the gravel to sink more in the downstream part of the upstream reach. The sand reach suffered from a larger degradation. Finally, we see one reach dominated by sand, small bedforms, and a small bed slope, and a gravel reach dominated by a larger bed slope.

Evaluation of the Load-Displacement Relationships for Large-Diameter Piles in Sand

DEFF Research Database (Denmark)

Sørensen, Søren Peder Hyldal; Brodbaek, K. T.; Moller, M.

2009-01-01

For laterally loaded piles in sand with diameters up to 6 m, e.g. monopiles used as foundations for offshore wind turbines, there is no approved design procedure. The p-y curve method, given in offshore design regulations, is usually employed for the design of monopiles. However, this method was ...

Comparison between predicted and observed sand waves and sand banks in the North Sea

NARCIS (Netherlands)

Hulscher, Suzanne J.M.H.; van den Brink, G.M.

2001-01-01

For the first time a prediction model of regular morphological patterns on the seabed was tested against observations of sand wave and sand bank occurrence in the entire North Sea. The model, which originates from first physical principles, predicts this occurrence via two dimensionless parameters

The formation of low-angle eolian stratification through the migration of protodunes

Science.gov (United States)

Ewing, R. C.; Phillips, J. D.; Weymer, B. A.; Barrineaux, P.; Bowling, R.; Nittrouer, J. A.

2017-12-01

Protodunes are low-relief, slipfaceless migrating bed forms that represent the emergent form of eolian sand dunes. Protodunes develop as cm-scale topography out of a flat bed of sand and evolve spatially and temporally into dunes with angle-of-repose slipfaces. Protodunes at White Sands Dune Field in New Mexico form at the upwind, trailing margin of the field, on dune stoss slopes, and in interdune areas. Here we analyze protodunes at the upwind margin of White Sands by coupling 200 mHz ground penetrating radar (GPR) with time-series high-resolution topography to characterize the origin and evolution of protodune stratification and the stratigraphic transition into fully developed dunes. We surveyed a 780m transect in the resultant transport direction of the dune field from SW to NE from sand patches through protodunes and into the first dune. We used airborne lidar surveys and structure-from-motion photogrammetry from 2007, 2008, 2009, 2010, 2015, and 2016. We find that protodune stratification forms at angles between 0-10 degrees by protodune migration. Dip angles increase as protodune amplitude increases along the transect. Accumulation of low-angle stratification increases across the first 650m and ranges from none to subcritical. Nearly aggradational accumulation of low-angle stratification occurs over the last 100m and is a precursor to angle-of-repose slipface formation. The origins of the aggradation and slipface development appear to be linked to protodune merging, dune interactions, and possibly to the development of a dune field-scale boundary layer. Protodunes and the formation of low-angle stratification at the upwind margin of White Sands are a good analog to the initiation of dune field development from sand sheets and the formation of low-angle stratification found at the base of eolian successions in the stratigraphic record.

Critical State of Sand Matrix Soils

Science.gov (United States)

Marto, Aminaton; Tan, Choy Soon; Makhtar, Ahmad Mahir; Kung Leong, Tiong

2014-01-01

The Critical State Soil Mechanic (CSSM) is a globally recognised framework while the critical states for sand and clay are both well established. Nevertheless, the development of the critical state of sand matrix soils is lacking. This paper discusses the development of critical state lines and corresponding critical state parameters for the investigated material, sand matrix soils using sand-kaolin mixtures. The output of this paper can be used as an interpretation framework for the research on liquefaction susceptibility of sand matrix soils in the future. The strain controlled triaxial test apparatus was used to provide the monotonic loading onto the reconstituted soil specimens. All tested soils were subjected to isotropic consolidation and sheared under undrained condition until critical state was ascertain. Based on the results of 32 test specimens, the critical state lines for eight different sand matrix soils were developed together with the corresponding values of critical state parameters, M, λ, and Γ. The range of the value of M, λ, and Γ is 0.803–0.998, 0.144–0.248, and 1.727–2.279, respectively. These values are comparable to the critical state parameters of river sand and kaolin clay. However, the relationship between fines percentages and these critical state parameters is too scattered to be correlated. PMID:24757417

Effects of sand fences on coastal dune vegetation distribution

Science.gov (United States)

Grafals-Soto, Rosana

2012-04-01

Sand fences are important human adjustments modifying the morphology of developed shores. The effects of sand fences on sediment transport and deposition in their initial stages have been well studied, but little is known about the effect of deteriorated sand fences that have become partially buried low scale barriers within the dune, potentially benefiting vegetation growth by protecting it from onshore stress. Data on vegetation, topography and fence characteristics were gathered at three dune sites in Ocean City, New Jersey on September 2007 and March 2008 to evaluate the effect of fences within the dune on vegetation distribution. Variables include: distance landward of dune toe, degree of sheltering from onshore stressors, net change in surface elevation (deposition or erosion), vegetation diversity and density, presence of remnant fence, and distance landward of fence. Results for the studied environment reveal that 1) vegetation diversity or density does not increase near remnant fences because most remnants are lower than average vegetation height and can not provide shelter; but 2) vegetation distribution is related to topographic variables, such as degree of sheltering, that are most likely the result of sand accretion caused by fence deployment. Fence deployment that prioritizes the creation of topographically diverse dunes within a restricted space may increase the diversity and density of the vegetation, and the resilience and value of developed dunes. Managers should consider the benefits of using sand fences on appropriately wide beaches to create a protective dune that is also diverse, functional and better able to adapt to change.

Punctuated sediment record resulting from channel migration in a shallow sand-dominated micro-tidal lagoon, Northern Wadden Sea, Denmark

DEFF Research Database (Denmark)

Fruergaard, M.; Andersen, T.J.; Nielsen, L.H.

2011-01-01

depositional environment, but tidal channel sediments dominate in the five sediment cores, making up 56% of the 15 mof sediment core. Sedimentation in the lagoon alternated between slow vertical aggradation of sand flats (1.5–2 mm yr-1) and very fast lateral progradation of point bars in tidal channels, which...... caused the formation of a punctuated lagoonal fill. Frequent and comprehensive reworking of the sand flat sediments by tidal channel migration entails loss of sedimentary structures and bioturbation related to sand flat deposits, and old sand flat sediments are only very sparsely preserved. We further...... conclude that long-term (millennial timescale) sediment accumulation in the lagoon was controlled by rising sea-level, whereas short-term (centurial timescale) sediment accumulation was controlled by local erosion and depositional events caused by lateral migration of channels. Records of short-term sea...

Formulating Fine to Medium Sand Erosion for Suspended Sediment Transport Models

Directory of Open Access Journals (Sweden)

François Dufois

2015-08-01

Full Text Available The capacity of an advection/diffusion model to predict sand transport under varying wave and current conditions is evaluated. The horizontal sand transport rate is computed by vertical integration of the suspended sediment flux. A correction procedure for the near-bed concentration is proposed so that model results are independent of the vertical resolution. The method can thus be implemented in regional models with operational applications. Simulating equilibrium sand transport rates, when erosion and deposition are balanced, requires a new empirical erosion law that involves the non-dimensional excess shear stress and a parameter that depends on the size of the sand grain. Comparison with several datasets and sediment transport formulae demonstrated the model’s capacity to simulate sand transport rates for a large range of current and wave conditions and sand diameters in the range 100–500 μm. Measured transport rates were predicted within a factor two in 67% of cases with current only and in 35% of cases with both waves and current. In comparison with the results obtained by Camenen and Larroudé (2003, who provided the same indicators for several practical transport rate formulations (whose means are respectively 72% and 37%, the proposed approach gives reasonable results. Before fitting a new erosion law to our model, classical erosion rate formulations were tested but led to poor comparisons with expected sediment transport rates. We suggest that classical erosion laws should be used with care in advection/diffusion models similar to ours, and that at least a full validation procedure for transport rates involving a range of sand diameters and hydrodynamic conditions should be carried out.

Production and global transport of Titan's sand particles

Science.gov (United States)

Barnes, Jason W.; Lorenz, Ralph D.; Radebaugh, Jani; Hayes, Alexander G.; Arnold, Karl; Chandler, Clayton

2015-06-01

Previous authors have suggested that Titan's individual sand particles form by either sintering or by lithification and erosion. We suggest two new mechanisms for the production of Titan's organic sand particles that would occur within bodies of liquid: flocculation and evaporitic precipitation. Such production mechanisms would suggest discrete sand sources in dry lakebeds. We search for such sources, but find no convincing candidates with the present Cassini Visual and Infrared Mapping Spectrometer coverage. As a result we propose that Titan's equatorial dunes may represent a single, global sand sea with west-to-east transport providing sources and sinks for sand in each interconnected basin. The sand might then be transported around Xanadu by fast-moving Barchan dune chains and/or fluvial transport in transient riverbeds. A river at the Xanadu/Shangri-La border could explain the sharp edge of the sand sea there, much like the Kuiseb River stops the Namib Sand Sea in southwest Africa on Earth. Future missions could use the composition of Titan's sands to constrain the global hydrocarbon cycle.

High temperature thermal energy storage in moving sand

Science.gov (United States)

Turner, R. H.; Awaya, H. I.

1978-01-01

Several high-temperature (to 500 C) heat-storage systems using sand as the storage medium are described. The advantages of sand as a storage medium include low cost for sand, widespread availability, non-toxicity, non-degradation characteristics, easy containment, and safety. The systems considered include: stationary sand with closely spaced tubes throughout the volume, the use of a fluidized bed, use of conveyor belt transporter, and the use of a blower rapid transport system. For a stationary sand bed, very close spacing of heat transfer tubes throughout the volume is required, manifesting as high power related system cost. The suggestion of moving sand past or around pipes is intended to reduce the power related costs at the penalty of added system complexity. Preliminary system cost estimates are offered. These rough calculations indicate that mobile sand heat storage systems cost less than the stationary sand approach.

Sand to Root Transfer of PAHs and PCBs by Carrots Grown on Sand with Pure Substances and Biosolids Amended Sand

OpenAIRE

Sablayrolles, Caroline; Montréjaud-Vignoles, Mireille; Silvestre, Jérôme; Patria, Lucie

2006-01-01

A study on behaviour of trace organic compounds (Polycyclic Aromatic Hydrocarbons, PAH, and Polychlorinated Biphenyls, PCB) in a sand-plant system has been carried out, with the reclamation of wastewater treatment plant biosolids for agriculture in mind. Carrot plants (Daucus carota) were grown on soilless culture (sand), to provide optimal transfer conditions, in plant containers inside a temperature regulated greenhouse. There were two types of experiment. The trace organic compounds have i...

A practical method for estimating maximum shear modulus of cemented sands using unconfined compressive strength

Science.gov (United States)

Choo, Hyunwook; Nam, Hongyeop; Lee, Woojin

2017-12-01

The composition of naturally cemented deposits is very complicated; thus, estimating the maximum shear modulus (Gmax, or shear modulus at very small strains) of cemented sands using the previous empirical formulas is very difficult. The purpose of this experimental investigation is to evaluate the effects of particle size and cement type on the Gmax and unconfined compressive strength (qucs) of cemented sands, with the ultimate goal of estimating Gmax of cemented sands using qucs. Two sands were artificially cemented using Portland cement or gypsum under varying cement contents (2%-9%) and relative densities (30%-80%). Unconfined compression tests and bender element tests were performed, and the results from previous studies of two cemented sands were incorporated in this study. The results of this study demonstrate that the effect of particle size on the qucs and Gmax of four cemented sands is insignificant, and the variation of qucs and Gmax can be captured by the ratio between volume of void and volume of cement. qucs and Gmax of sand cemented with Portland cement are greater than those of sand cemented with gypsum. However, the relationship between qucs and Gmax of the cemented sand is not affected by the void ratio, cement type and cement content, revealing that Gmax of the complex naturally cemented soils with unknown in-situ void ratio, cement type and cement content can be estimated using qucs.

Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs

Energy Technology Data Exchange (ETDEWEB)

Maria Cecilia Bravo

2006-06-30

This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.

Analysis of wind-blown sand movement over transverse dunes.

Science.gov (United States)

Jiang, Hong; Huang, Ning; Zhu, Yuanjian

2014-12-01

Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.

Geology and resources of the Tar Sand Triangle, southeastern Utah

Energy Technology Data Exchange (ETDEWEB)

Dana, G.F.; Oliver, R.L.; Elliott, J.R.

1984-05-01

The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyonlands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well-sorted sandstone which was deposited in a shallow marine environment. Resources were calculated from analytical data from the three coreholes drilled by the Laramie Energy Technology Center and other available data. The total in-place resources, determined from this study, are 6.3 billion barels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses will be necessary before a more accurate determination of resources can be attempted. 8 references, 11 figures, 7 tables.

Sand consolidation

Energy Technology Data Exchange (ETDEWEB)

Spain, H H

1965-01-21

In a sand consolidation method in which there is injected a mixture of resin-forming liquids comprising an aryl-hydroxy low molecular weight compound, a water- soluble aldehyde, and a catalyst, an improvement is claimed which comprises diluting the resin-forming liquids with a diluent and with water so that the yield of the resin is sufficient to consolidate the sand particles with the minimum desirable pressure. The diluent may be mutually soluble in water and in the resin-forming liquids, and does not affect the setting time of the polymer. The aldehyde and the aryl-hydroxy compound may be in ratio of 5:1, and the diluent, methyl alcohol, is present in a ratio of 2:1 with reference to the water.

Oil sands mining and reclamation cause massive loss of peatland and stored carbon

Science.gov (United States)

Rooney, Rebecca C.; Bayley, Suzanne E.; Schindler, David W.

2012-01-01

We quantified the wholesale transformation of the boreal landscape by open-pit oil sands mining in Alberta, Canada to evaluate its effect on carbon storage and sequestration. Contrary to claims made in the media, peatland destroyed by open-pit mining will not be restored. Current plans dictate its replacement with upland forest and tailings storage lakes, amounting to the destruction of over 29,500 ha of peatland habitat. Landscape changes caused by currently approved mines will release between 11.4 and 47.3 million metric tons of stored carbon and will reduce carbon sequestration potential by 5,734–7,241 metric tons C/y. These losses have not previously been quantified, and should be included with the already high estimates of carbon emissions from oil sands mining and bitumen upgrading. A fair evaluation of the costs and benefits of oil sands mining requires a rigorous assessment of impacts on natural capital and ecosystem services. PMID:22411786

A cost comparison of nuclear and fossil power for the Alberta tar sands

International Nuclear Information System (INIS)

Sochaski, R.O.; Smith, D.W.

1977-04-01

One technique envisaged for commercial development of the Alberta tar sands is in-situ removal of bitumen by injection of steam into the formation at high temperature and pressure. The 3000 MW of thermal power required for a typical 20 Gg/d plant could be supplied by a nuclear reactor. Accordingly, an economic comparison was made between a CANDU organic-cooled reactor and a conventional coal-fired station, using a variety of financial ground rules. This analysis shows that for debt-financed cases, nuclear power has essentially no economic competition from coal. For equity cases, the competitive position of a coal-fired station is heavily dependent on the cost of coal delivered to the tar sands area, discount rate, amortization period and inflation rate. (author)

Sands at Gusev Crater, Mars

Science.gov (United States)

Cabrol, Nathalie A.; Herkenhoff, Kenneth E.; Knoll, Andrew H.; Farmer, Jack D.; Arvidson, Raymond E.; Grin, E.A.; Li, Ron; Fenton, Lori; Cohen, B.; Bell, J.F.; Yingst, R. Aileen

2014-01-01

Processes, environments, and the energy associated with the transport and deposition of sand at Gusev Crater are characterized at the microscopic scale through the comparison of statistical moments for particle size and shape distributions. Bivariate and factor analyses define distinct textural groups at 51 sites along the traverse completed by the Spirit rover as it crossed the plains and went into the Columbia Hills. Fine-to-medium sand is ubiquitous in ripples and wind drifts. Most distributions show excess fine material, consistent with a predominance of wind erosion over the last 3.8 billion years. Negative skewness at West Valley is explained by the removal of fine sand during active erosion, or alternatively, by excess accumulation of coarse sand from a local source. The coarse to very coarse sand particles of ripple armors in the basaltic plains have a unique combination of size and shape. Their distribution display significant changes in their statistical moments within the ~400 m that separate the Columbia Memorial Station from Bonneville Crater. Results are consistent with aeolian and/or impact deposition, while the elongated and rounded shape of the grains forming the ripples, as well as their direction of origin, could point to Ma'adim Vallis as a possible source. For smaller particles on the traverse, our findings confirm that aeolian processes have dominated over impact and other processes to produce sands with the observed size and shape patterns across a spectrum of geologic (e.g., ripples and plains soils) and aerographic settings (e.g., wind shadows).

Sedimentary Facies of the West Crocker Formation North Kota Kinabalu-Tuaran Area, Sabah, Malaysia

Science.gov (United States)

Mohamed, Azfar; Hadi Abd Rahman, Abdul; Suhaili Ismail, Mohd

2016-02-01

Newly outcrops exposed in the West Crocker Formation have led to the detail sedimentolgical analysis of the formation. Eight sedimentary facies have been recognised in which it was divided into three main groups: (1) sand-dominated facies (F1-F2), (2) poorly- sorted unit mixed sand and mud-dominated facies (F3), and (3) mud-dominated facies (F4-F5). These are: F1- graded sandstone (massive to planar laminated), F2-ripple-cross laminated, wavy and convolute lamination sandstone, F3-chaotic beds of mixed sandstone and mudstone blocks and clasts, F4-lenticular bedded of sandstone, and F5-shale. The studies of the formation has come out that it was deposited in a sand-rich submarine fan with specific location located at (1) inner fan channel-levee complex; (2) mid-fan channelised lobes, and (3) outer fan.

A biocoagulant slow sand filtration for disinfection of Toxoplasma ...

African Journals Online (AJOL)

An integrated low-tech biocoagulant-sand filter drum for disinfection of oocysts of Toxoplasma gondii targeted for developing countries was evaluated. Dirty and turbid water (130.3 NTU) from Mezam River and leachates from dump sites and stagnant water in Bamenda, Cameroon, was analyzed microscopically after ...

Mining aspects of hard to access oil sands deposits

Energy Technology Data Exchange (ETDEWEB)

Stephenson, G.; Wright, D.; Lukacs, Z. [Norwest Corp., Calgary, AB (Canada)

2006-07-01

While a variety of oil sands mining technologies have been explored since the 1960s, the oil sands industry has generally favoured truck and shovel mining as a proven, low-cost mining solution. However, surface mining economics are affected by the price of bitumen, haul distances, tailings storage and geotechnical constraints. Maintenance, labour and the cost of replacing tires and ground engaging tools also have a significant impact on the economics of surface mining. Large volumes of water are used in surface mining, and remediation of surface mined areas can take hundreds of years. Damage to machinery is common as oil sands are abrasive and adhere to equipment. This presentation examined recent technologies developed to improve the economics of surface mining. Various extraction and tailings technologies were reviewed. Issues concerning the integration of mining and extraction processes were discussed. Various monitoring tools were evaluated. A review of new underground mining options included outlines of: longwall mining; sub-level caving; tunnel boring; and room and pillar extraction techniques. A generalized regional geology was presented. It was concluded that the oil sands surfacing mining industry should concentrate on near-term research needs to improve the performance and economics of proven technologies. Screening studies should also be conducted to determine the focus for the development of underground technologies. refs., tabs., figs.

Direct Chlorination of Zircon Sand

International Nuclear Information System (INIS)

Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

2002-01-01

It was investigated the direct chlorination of zircon sand in a unit chlorination equipment. The process was in semi batch. The product gas was scrubbed in aqueous NaOH. It was search the influence of time, ratio of reactant and size of particle sand to the concentration of Zr and Si in the product. From these research it was found that as the times, ratio of reactant increased, the concentration of Zr increased, but the concentration of Si decreased, while as grain size of zircon sand decreased the concentration of Zr decreased, but the concentration of Si increased. (author)

Horizontal drilling in Miocene thin sand of Lake Maracaibo

Energy Technology Data Exchange (ETDEWEB)

Partidas, C. [PDVSA Exploration and Production (Venezuela)

1998-12-31

Horizontal drilling in the mature Lake Maracaibo field in Venezuela as a means of stimulating production are discussed. The Miocene sand where the horizontal well technology was applied, presented a number of intervals of unconsolidated sand of varied continuity, pay intervals at ten to twenty feet thickness, and reservoir pressures mostly at hydrostatic or below hydrostatic values. This paper evaluates a horizontal drilling program in the Lagunallis Lago Production Unit of Maracaibo, involving 91 wells to date (since 1995). When assessed in economic terms, results indicate that horizontal wells are a better economic alternative than vertical wells. The same results also showed that drainage from thin sand reservoirs resulted in better production with horizontal well technology than production from vertical wells. Payout was less than two years for 50 per cent of the horizontal wells while 40 per cent had payouts of between two and four years. Profit to investment ratio was greater than two in the case of about 70 per cent of the horizontal wells drilled in 1996. 2 tabs., 10 figs.

Chenier plain development: feedbacks between waves, mud and sand

Science.gov (United States)

Nardin, W.; Fagherazzi, S.

2015-12-01

Cheniers are sandy ridges parallel to the coast established by high energy waves. Here we discuss Chenier plains ontogeny through dimensional analysis and numerical results from the morphodynamic model Delft3D-SWAN. Our results show that wave energy and shelf slope play an important role in the formation of Chenier plains. In our numerical experiments waves affect Chenier plain development in three ways: by winnowing sediment from the mudflat, by eroding mud and accumulating sand over the beach during extreme wave events. We further show that different sediment characteristics and wave climates can lead to three alternative coastal landscapes: strand plains, mudflats, or the more complex Chenier plains. Low inner-shelf slopes are the most favorable for strand plain and Chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation.

Thermal Conductivity of Polymer Composite poypropilene-Sand

International Nuclear Information System (INIS)

Betha; Mashuri; Sudirman; Karo Karo, Aloma

2001-01-01

Thermal conductivity composite materials polypropylene (PP)-sand have been investigated. PP composite with sand to increase thermal conductivity from the polymer. The composite in this observation is done by mixing matrix (PP melt flow 2/10)and filler sand)by means tool labo plastomil. The result of thermal conductivity is composite of PP-sand which is obtained increase and followed by the raising of filler particle volume fraction. The analysis of thermal conductivity based on the model Cheng and Vachon, model Lewis and Nielsen where this model has the function to support experiment finding. It is proved that Lewis' and Nielsen's model almost approach experiment result. And then thermal conductivity raising will be analyzed by the model of pararel-series conductive with the two (2)phases system. It is showed that sand in PP MF 2 composite have the big role to increase the thermal conductivity than sand in PP MF 10 composition, but it is not easy to shape conductive medium

Final report on Thermally Modified Sand demonstration project

Energy Technology Data Exchange (ETDEWEB)

1994-09-23

The use of salt and salt/sand mixtures on icy roadway surfaces has dramatically increased during the past 30 years. Despite extensive documentation on salt related damage to the roadway improvements, vehicles and the environment, road maintenance departments have continued to rely on this practice. Road maintenance departments in northern climate areas have long recognized the safety benefits for public mobility on icy roadways from the use of sand. As an abrasive material, the sand improves the surface traction that results in more drivable and less hazardous road conditions during the winter months. Stockpiles of pure sand stored during the winter months oftentimes freeze into large unworkable, monolithic piles. To maintain a free-flowing condition, it has been found to be necessary to add salt to the sand. The addition of salt in amounts ranging from 5 to 10 percent to that of sand, is usually sufficient to provide relatively free-flowing abrasive material that could be stored in stockpiles and applied to icy road surfaces with conventional sand spreading trucks. Another alternative for winter storage of pure sand to maintain a free-flowing condition is in humidity-controlled, heated buildings. As would be expected, this method has high capital and operating costs. and not cost effective for general highway maintenance use. The invention demonstrated herein is a method of thermally modifying pure sand that will remain in a free-flowing state throughout the winter season without the need for the salt additive. The thermally modified sand provides an abrasive material that when applied to icy roads does not cause environmental and corrosive damage as done by the application of sand with salt. By employing a very simple process of freezing screened sand particles by forced air convection under subfreezing conditions, the invention creates a product that has significant value in terms of economic and environmental benefits.

Soft-Sediment Deformation Structures Interpreted as Seismites in the Kolankaya Formation, Denizli Basin (SW Turkey)

Science.gov (United States)

Topal, Savaş; Özkul, Mehmet

2014-01-01

The NW-trending Denizli basin of the SW Turkey is one of the neotectonic grabens in the Aegean extensional province. It is bounded by normal faults on both southern and northern margins. The basin is filled by Neogene and Quaternary terrestrial deposits. Late Miocene- Late Pliocene aged Kolankaya formation crops out along the NW trending Karakova uplift in the Denizli basin. It is a typical fluviolacustrine succession that thickens and coarsens upward, comprising poorly consolidated sand, gravelly sand, siltstone and marl. Various soft-sediment deformation structures occur in the formation, especially in fine- to medium grained sands, silts and marls: load structures, flame structures, clastic dikes (sand and gravely-sand dike), disturbed layers, laminated convolute beds, slumps and synsedimentary faulting. The deformation mechanism and driving force for the soft-sediment deformation are related essentially to gravitational instability, dewatering, liquefaction-liquidization, and brittle deformation. Field data and the wide lateral extent of the structures as well as regional geological data show that most of the deformation is related to seismicity and the structures are interpreted as seismites. The existence of seismites in the Kolankaya Formation is evidence for continuing tectonic activity in the study area during the Neogene and is consistent with the occurrence of the paleoearthquakes of magnitude >5. PMID:25152909

Study on sand particles creep model and open pit mine landslide mechanism caused by sand fatigue liquefaction

Science.gov (United States)

Du, Dong-Ning; Wang, Lai-Gui; Zhang, Xiang-Dong; Zhang, Shu-Kun

2017-06-01

The sand particles in the sand - rock composite slope of the open pit mine occurs creep deformation and fatigue liquefaction under the action of vehicle load vibration and hydraulic gradient, which causes landslide geological disasters and it destroys the surface environment. To reveal the mechanism, a mechanics model based on the model considering the soil structural change with a new “plastic hinge” element is developed, to improve its constitutive and creep curve equations. Data from sand creep experiments are used to identify the parameters in the model and to validate the model. The results show that the mechanical model can describe the rotation progress between the sand particles, disclose the negative acceleration creep deformation stage during the third phase, and require fewer parameters while maintaining accuracy. It provides a new creep model considering rotation to analyze sand creep mechanism, which provides a theoretical basis for revealing the open pit mine landslide mechanism induced by creep deformation and fatigue liquefaction of sandy soil.

Retorting of bituminous sands

Energy Technology Data Exchange (ETDEWEB)

Chaney, P E; Ince, R W; Mason, C M

1872-09-26

This method of recovering oil from mined tar sands involves forming compacted tar sands pieces by special conditioning treatment that provides low internal permeability. The compacted pieces are then retorted in fixed bed form. The conditioning treatment can involve rolling of preformed pellets, compaction in a mold or pressure extrusion. Substantial collapsing of the bed during retorting is avoided. (9 claims) (Abstract only - original article not available from T.U.)

[Effect of concomitant substances and addition order on the adsorption of Tween 80 on sand].

Science.gov (United States)

Xu, Wei; Zhao, Yong-sheng; Li, Sui; Dai, Ning

2008-08-01

Adsorption of Tween 80 on sand was investigated, and the effect of inorganic salts (CaCl2), anionic surfactant (SDS) and lignosulphonates (sodium lignosulphonate or ammonium lignosulphonate) on the adsorption of Tween 80 on sand were evaluated at 25 degrees C. The results show that saturated adsorption amount of Tween 80 on sand enhance when CaCl2 or SDS is added into flushing solution of Tween 80. And the adsorption of Tween 80 on sand increase with the increase of molar fraction of CaCl2 or SDS in mixed flushing solution. And adsorption amount of Tween 80 on sand also enhance when SDS is added into sand firstly. The effects of mixing ratios and addition order of lignosulphonates on adsorption of Tween 80 were considered. The results show that with the increase of molar fraction of lignosulphonates in mixing flushing solution, adsorption amount of Tween 80 on sand decrease. The adsorption amount of Tween 80 reduce 20%-75% due to the exist of ammonium lignosulphonate is superior to sodium lignosulphonate (10%-60%) when mix the lignosulphonates-Tween 80 at the total mass ratios of 1:10, while the adsorption amount of Tween 80 reduce 70%-90% at the total mass ratios of 1:2. Lignosulphonates added into sand firstly is more efficient than that together. Therefore,use of lignosulphonates as a preflush can reduce the adsorption of surfactants on sand and is a better method to applied in in situ flushing.

Second quarter technical progress report for Thermally Modified Sand

Energy Technology Data Exchange (ETDEWEB)

1994-06-14

The objective was to have the Alaska Department of Transportation & Public Facilities Operation & Maintenance Section use Thermally Modified Sand (TMS) for treatment of icy state roadways. The project included the evaluation on the workability of a large stockpile of TMS material left undisturbed throughout the 1993/94 winter season.

Experimental and numerical study on thermal conductivity of partially saturated unconsolidated sands

Science.gov (United States)

Lee, Youngmin; Keehm, Youngseuk; Kim, Seong-Kyun; Shin, Sang Ho

2016-04-01

A class of problems in heat flow applications requires an understanding of how water saturation affects thermal conductivity in the shallow subsurface. We conducted a series of experiments using a sand box to evaluate thermal conductivity (TC) of partially saturated unconsolidated sands under varying water saturation (Sw). We first saturated sands fully with water and varied water saturation by drainage through the bottom of the sand box. Five water-content sensors were integrated vertically into the sand box to monitor water saturation changes and a needle probe was embedded to measure thermal conductivity of partially saturated sands. The experimental result showed that thermal conductivity decreases from 2.5 W/mK for fully saturated sands to 0.7 W/mK when water saturation is 5%. We found that the decreasing trend is quite non-linear: highly sensitive at very high and low water saturations. However, the boundary effects on the top and the bottom of the sand box seemed to be responsible for this high nonlinearity. We also found that the determination of water saturation is quite important: the saturation by averaging values from all five sensors and that from the sensor at the center position, showed quite different trends in the TC-Sw domain. In parallel, we conducted a pore-scale numerical modeling, which consists of the steady-state two-phase Lattice-Boltzmann simulator and FEM thermal conduction simulator on digital pore geometry of sand aggregation. The simulation results showed a monotonous decreasing trend, and are reasonably well matched with experimental data when using average water saturations. We concluded that thermal conductivity would decrease smoothly as water saturation decreases if we can exclude boundary effects. However, in dynamic conditions, i.e. imbibition or drainage, the thermal conductivity might show hysteresis, which can be investigated with pore-scale numerical modeling with unsteady-state two-phase flow simulators in our future work.

Ultrasonic Monitoring of CO2 Uptake and Release from Sand Packs*

Science.gov (United States)

Toffelmier, D. A.; Dufrane, W. L.; Bonner, B. P.; Viani, B. E.; Berge, P. A.

2002-12-01

Sequestration of atmospheric CO2 occurs naturally during the formation of calcite cement in sedimentary rock. Acceleration of this process has been proposed as a means of reducing the atmospheric concentration of CO2, which is a major cause of global warming. Calcite may also be precipitated when highly alkaline waste fluid is introduced into the vadose zone from leaking storage tanks. Seismic methods have potential for monitoring these processes. We devised an experiment, guided by geochemical modeling, to determine how the formation of calcite cement in unsaturated sand affects wave propagation. We used the ultrasonic pulse transmission method to measure compressional (P) and shear (S) wave velocities at ultrasonic frequencies (100-500 kHz) through packs of Ottawa sand containing chemically active pore fluids. The samples were saturated with water containing 0.1mol/L of Ca(OH)2 and 0.1mol/L of NaCl and then drained by flowing water saturated, CO2 free N2 gas, to a residual saturation of ~5%, so that the remaining pore fluid resides mainly in pendular spaces between the sand grains. Ambient air saturated with water and containing atmospheric concentration of CO2 was then passed through the sample to effect the precipitation of calcite. Finally, pure water saturated CO2, was flushed through the sample to dissolve most of the precipitated calcite. Over a three day period, measurable changes in Vp and Vs were observed following water saturation, desaturation, calcite precipitation, and calcite dissolution treatments. Changes in the contents of the pore space require waveforms to be recorded before and after each stage of the experiment so both the short and long range effects can be seen. Wave velocities were slow, as is typical for unconsolidated materials, for the dry sand, with values of 365m/s for Vp and 163m/s for Vs. Compressional velocities increased upon desaturation (443m/s), and again following calcite precipitation (460m/s). The compressional velocity

K West Basin Sand Filter Backwash Sample Analysis

Energy Technology Data Exchange (ETDEWEB)

Fiskum, Sandra K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smoot, Margaret R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Deborah S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pool, Karl N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2016-03-01

in the insoluble solids; less than 1% of other gamma-emitters (i.e., ¹³⁷Cs, ^154/155Eu, and ²⁴¹Am) were present in the insoluble solids. Aliquots of the acid digestate were analyzed directly using gamma energy analysis (GEA) and after separations for ²³⁸Pu, ^239+240Pu, ²³⁷Np, and ²⁴¹Am radioisotopes using alpha energy analysis (AEA). The ⁹⁰Sr was measured by liquid scintillation counting (LSC) on the Sr-separated fraction. The plutonium isotopic distribution of the acid digestate was analyzed following Pu separations by thermal ionization mass spectrometry (TIMS). A table summarizes the results for the primary and duplicate samples. The ^239+240Pu concentration (µCi/g dry) relative to ⁹⁰Sr and to ¹³⁷Cs concentrations (µCi/g dry) was examined. The K West Basin sludge has a ^239+240Pu/⁹⁰Sr ranging from 0.1 to 1.2 and the ^239+240Pu/¹³⁷Cs ratio ranging from 0.10 to 0.47. In contrast, the sand filter backwash solids ^239+240Pu/⁹⁰Sr ratio was 10.6 and the ^239+240Pu/¹³⁷Cs ratio was 2.0. The ratio differences indicate a relative enhancement of the Pu concentration in the sand filter solids relative to the ¹³⁷Cs and ⁹⁰Sr sludge concentrations currently in the K West Basin. A dose-to-curie radioisotope evaluation of the sand filter waste form may need to consider this dissimilarity.

Numerical simulation of flow and compression of green sand

DEFF Research Database (Denmark)

Hovad, Emil

The focus of the industrial PhD project was concentrated on the production of the sand mold (green sand) which gives the cast component its final geometrical shape. In order to ensure a high quality of the cast component, it is important to control the manufacturing process of the mold itself so...... that it is homogeneous and stable. Therefore gaining a basic understanding of how the flow and deposition of green sand should be characterized and modelled was important, so that it could be used for simulation of the manufacturing process of the sand mold. The flowability of the green sand is important when the sand...... flows down through the hopper filling the chamber with sand during the sand shot. The flowability of green sand is mostly governed by the amount of water and bentonite which both decrease it. The flowability and the internal forces thus control how well you can fill a complex mold geom-etry in which...

Paleo-Environment and C-14 Dating: The Key to the Depositional Age of the Tha Chang and Related Sand Pits, Northeastern Thailand

Science.gov (United States)

Putthapiban, P.; Zolensky, M.; Jull, T.; Demartino, M.; Salyapongse, S.

2012-01-01

- Arizona AMS Laboratory. Although, there is no sharp boundary between the unconsolidated sedimentary horizons in the pits, C-14 ages obtained from the Tha Chang vary from 34,340 BP at the middle horizon (approx 10 m below ground zero) to >49,900 BP at the lower horizon with unknown basal formation (highly pyritized zone approx 20 - 25 m below ground zero). The ages for the Chumpuang vary from 41,700 BP, >45,900 BP and >49,900 BP from the upper most to the lower most of a broad horizon (approx 8 m to approx 12 m below ground zero). The C-14 age of the pottery collected from layer approximately 5 m below ground zero is 2,514 BP. The nature of fluviatile together with occasional mass wasting characteristics of all sand pits studies suggest the relatively faster depositional rate of the lower horizon which involved more flooding and mass wasting deposits than those of the upper horizons. The apparent of some mixing of the wood ages may indicate reworking and lag deposits nature of the area. The depositional rate of the upper most sand and soil horizon (5 m thick) is approximately 1 m per 500 years which mean both erosion and deposition had played a significant role during that time period. In term of the true age of the formation, we argue that since most of the materials deposited are reworked materials, all ages obtained from fossil fragments could not be the age of sand and gravel formation. Furthermore, the maximum age of all the tektite bearing horizons cannot be older than 0.8 Ma. The oldest C-14 age of 49,900 BP is interpreted as the minimum age of the Tha Chang and related sand pits formation when geomorphology of the area was a lot more hilly and much higher gradient than that of the present day.

Sand wave fields beneath the Loop Current, Gulf of Mexico: Reworking of fan sands

Science.gov (United States)

Kenyon, Neil H.; Akhmetzhanov, A.M.; Twichell, D.C.

2002-01-01

Extensive fields of large barchan-like sand waves and longitudinal sand ribbons have been mapped by deep-towed SeaMARC IA sidescan sonar on part of the middle and lower Mississippi Fan that lies in about 3200 m of water. The area is beneath the strongly flowing Loop Current. The bedforms have not been adequately sampled but probably consist of winnowed siliciclastic-foraminiferal sands. The size (about 200 m from wingtip to wingtip) and shape of the large barchans is consistent with a previously observed peak current speed of 30 cm/s, measured 25 m above the seabed. The types of small-scale bedforms and the scoured surfaces of chemical crusts, seen on nearby bottom photographs, indicate that near-bed currents in excess of 30 cm/s may sometimes occur. At the time of the survey the sand transport direction was to the northwest, in the opposite direction to the Loop Current but consistent with there being a deep boundary current along the foot of the Florida Escarpment. Some reworking of the underlying sandy turbidites and debris flow deposits is apparent on the sidescan sonar records. Reworking by deep-sea currents, resulting in erosion and in deposits characterised by coarsening upwards structures and cross-bedding, is a process that has been proposed for sand found in cores in shallower parts of the Gulf of Mexico. This process is more widespread than hitherto supposed. 

Oil sands and the environment

Energy Technology Data Exchange (ETDEWEB)

Seeley, R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

2004-07-01

Oil sands are a significant resource for Alberta and Canada with continuing growth opportunity. There is a need to ensure sustainable development of the oil sands resources from a social, economic and environmental perspective. The industry has succeeded in terms of proven reserves, technology advancements, reduced operating costs, reliability and market accessibility. Some of the major challenges facing the industry include high capital cost, infrastructure, social services and keeping pace with growth. This presentation outlined the proactive measures that the oil sands industry has taken to manage environmental issues such as sulphur dioxide and nitrogen oxide emissions, greenhouse gases, water management and land reclamation. tabs., figs.

Alberta oil sands royalty regime

International Nuclear Information System (INIS)

Asgarpour, S.

2004-01-01

The long term objective of the Oil Sands Business Unit of Alberta Energy is to pave the way for Alberta's bitumen production to reach 3 million barrels per day by 2020. This presentation described the national government's role in resource development. It was emphasized that since the Crown is the owner of the oil sands resource, it would benefit by providing strategic leadership and by generating a larger royalty base. The oil sands fiscal regime was described with reference to generic royalty, risk sharing, investment, and project economics. Business rule principles were also outlined along with criteria for project expansions. Both upstream and downstream challenges and opportunities were listed. 4 figs

Experimental study of optimal self compacting concrete with spent foundry sand as partial replacement for M-sand using Taguchi approach

Directory of Open Access Journals (Sweden)

Nirmala D.B.

2016-06-01

Full Text Available This paper presents the application of Taguchi approach to obtain optimal mix proportion for Self Compacting Concrete (SCC containing spent foundry sand and M-sand. Spent foundry sand is used as a partial replacement for M-sand. The SCC mix has seven control factors namely, Coarse aggregate, M-sand with Spent Foundry sand, Cement, Fly ash, Water, Super plasticizer and Viscosity modifying agent. Modified Nan Su method is used to proportion the initial SCC mix. L18 (21×37 Orthogonal Arrays (OA with the seven control factors having 3 levels is used in Taguchi approach which resulted in 18 SCC mix proportions. All mixtures are extensively tested both in fresh and hardened states to verify whether they meet the practical and technical requirements of SCC. The quality characteristics considering “Nominal the better” situation is applied to the test results to arrive at the optimal SCC mix proportion. Test results indicate that the optimal mix satisfies the requirements of fresh and hardened properties of SCC. The study reveals the feasibility of using spent foundry sand as a partial replacement of M-sand in SCC and also that Taguchi method is a reliable tool to arrive at optimal mix proportion of SCC.

Experimental study of optimal self compacting concrete with spent foundry sand as partial replacement for M-sand using Taguchi approach

Science.gov (United States)

Nirmala, D. B.; Raviraj, S.

2016-06-01

This paper presents the application of Taguchi approach to obtain optimal mix proportion for Self Compacting Concrete (SCC) containing spent foundry sand and M-sand. Spent foundry sand is used as a partial replacement for M-sand. The SCC mix has seven control factors namely, Coarse aggregate, M-sand with Spent Foundry sand, Cement, Fly ash, Water, Super plasticizer and Viscosity modifying agent. Modified Nan Su method is used to proportion the initial SCC mix. L18 (21×37) Orthogonal Arrays (OA) with the seven control factors having 3 levels is used in Taguchi approach which resulted in 18 SCC mix proportions. All mixtures are extensively tested both in fresh and hardened states to verify whether they meet the practical and technical requirements of SCC. The quality characteristics considering "Nominal the better" situation is applied to the test results to arrive at the optimal SCC mix proportion. Test results indicate that the optimal mix satisfies the requirements of fresh and hardened properties of SCC. The study reveals the feasibility of using spent foundry sand as a partial replacement of M-sand in SCC and also that Taguchi method is a reliable tool to arrive at optimal mix proportion of SCC.

EFFECTIVENESS OF THE SANDPITS SECURITY SYSTEM AGAINST MICROORGANISMS AND INTESTINAL PARASITES SAND CONTAMINATION

Directory of Open Access Journals (Sweden)

Magdalena Błaszak

2015-09-01

Full Text Available Playgrounds and sandpits (small architecture objects according to the Construction Law are subject to meticulous supervision, both at the design stage and subsequent status checks of the objects. One of the requirements arising from the need to protect playgrounds from animals is the necessity for fencing the object (Regulation of 31 December 2002 On Safety and Hygiene in Public and Private Schools and Institutions; Polish Standard PN-EN 1176 Playground equipment and surfacing. Does fencing playgrounds really reduce contamination of sand? To verify this hypothesis, the studies have been conducted on the residential areas’ sandpits, both fence secured and unsecured, located in close proximity to one another. The aim of the study was to evaluate the effectiveness of fences and nets as protection from microbial and parasite contamination of sandpits, mainly due to the access of animals to them. For several seasons of spring and summer the sand was examined in terms of the total number of heterotrophic bacteria and fungi (organic matter contamination of sand indicators and for the presence of coliform bacteria (including Escherichia coli, bacteria of the Salmonella genus and the eggs of intestinal parasites. It can be concluded that fencing playgrounds affects sand pollution less with waste and plant material (as a consequence, it has been reported statistically significantly less heterotrophic bacteria and fungi in the fenced sandpits’ sand. Unfortunately, the fence does not eliminate the risks associated with sand pollution of coliform bacteria. Cats and birds, but also dogs, still have a continuous access to sand. Due to the repeatedly stated carelessness of children and their caregivers, gates left open to the playground do not constitute an obstacle for domestic and stray animals. Another source of sand pollution with intestinal pathogens can be a manner of carriage of new sand, as there is no legislation governing the issue of transport

Clean energy and hydrogen for oil sands development with CANDU SCWR nuclear reactors and Cu-Cl cycles

International Nuclear Information System (INIS)

Wang, Z.L.; Naterer, G.F.; Gabriel, K.S.

2010-01-01

In this paper, the unique capabilities and advantages of SCWR technology for cleaner oil sands development are discussed from two perspectives: lower temperature steam generation by supercritical water for steam assisted gravity drainage (SAGD), and hydrogen production for oil sands upgrading by coupling SCWR with the thermochemical copper-chlorine (Cu-Cl) cycle. The heat requirements for bitumen extraction from the oil sands and the hydrogen requirements for bitumen upgrading are evaluated. A conceptual layout of SCWR coupled with oil sands development is presented. The reduction of CO 2 emissions due to the use of SCWR and thermo chemical hydrogen production cycle is also analyzed. (author)

Invasive plants on disturbed Korean sand dunes

Science.gov (United States)

Kim, Kee Dae

2005-01-01

The sand dunes in coastal regions of South Korea are important ecosystems because of their small size, the rare species found in this habitat, and the beautiful landscapes they create. This study investigated the current vegetative status of sand dunes on three representative coasts of the Korean peninsula, and on the coasts of Cheju Island, and assessed the conditions caused by invasive plants. The relationships between the degree of invasion and 14 environmental variables were studied. Plots of sand dunes along line transects perpendicular to the coastal lines were established to estimate vegetative species coverage. TWINSPAN (Two-Way Indicator Species Analysis), CCA (Canonical Correspondence Analysis), and DCCA (Detrended Canonical Correspondence Analysis) were performed to classify communities on sand dunes and assess species composition variation. Carex kobomugi, Elymus mollis, and Vitex rotundifolia were found to be the dominant species plotted on the east, the west, and the peripheral coasts of Cheju Island, respectively. Vegetation on the south coast was totally extinct. The 19 communities, including representative C. kobomugi, C. kobomugi- Ixeris repens, C. kobomugi- Oenothera biennis, E. mollis, Lolium multiflorum- Calystegia soldanella, and V. rotundifolia- C. kobomugi, were all classified according to TWINSPAN. Oenothera biennis and L. multiflorum were exotics observed within these native communities. CCA showed that invasive native and exotic species distribution was segregated significantly, according to disturbance level, exotic species number, gravel, sand and silt contents, as well as vegetation size. It further revealed that human disturbance can strongly favor the settlement of invasive and exotic species. Restoration options to reduce exotic plants in the South Korean sand dune areas were found to be the introduction of native plant species from one sand dune into other sand dune areas, prohibition of building and the introduction of exotic

Disinfection byproduct formation during biofiltration cycle: Implications for drinking water production.

Science.gov (United States)

Delatolla, R; Séguin, C; Springthorpe, S; Gorman, E; Campbell, A; Douglas, I

2015-10-01

The goal of this study was to investigate the potential of biofiltration to reduce the formation potential of disinfection byproducts (DBPs). Particularly, the work investigates the effect of the duration of the filter cycle on the formation potential of total trihalomethanes (TTHM) and five species of haloacetic acids (HAA5), dissolved oxygen (DO), organic carbon, nitrogen and total phosphorous concentrations along with biofilm coverage of the filter media and biomass viability of the attached cells. The study was conducted on a full-scale biologically active filter, with anthracite and sand media, at the Britannia water treatment plant (WTP), located in Ottawa, Ontario, Canada. The formation potential of both TTHMs and HAA5s decreased due to biofiltration. However the lowest formation potentials for both groups of DBPs and or their precursors were observed immediately following a backwash event. Hence, the highest percent removal of DBPs was observed during the early stages of the biofiltration cycle, which suggests that a higher frequency of backwashing will reduce the formation of DBPs. Variable pressure scanning electron microscopy (VPSEM) analysis shows that biofilm coverage of anthracite and sand media increases as the filtration cycle progressed, while biomass viability analysis demonstrates that the percentage of cells attached to the anthracite and sand media also increases as the filtration cycle progresses. These results suggest that the development and growth of biofilm on the filters increases the DPB formation potential. Copyright © 2015 Elsevier Ltd. All rights reserved.

The potential use of silica sand as nanomaterials for mortar

Science.gov (United States)

Setiati, N. Retno

2017-11-01

The development of nanotechnology is currently experiencing rapid growth. The use of the term nanotechnology is widely applied in areas such as healthcare, industrial, pharmaceutical, informatics, or construction. By the nanotechnology in the field of concrete construction, especially the mechanical properties of concrete are expected to be better than conventional concrete. This study aims to determine the effect of the potential of silica sand as a nanomaterial that is added into the concrete mix The methodology used consist of nanomaterial synthesis process of silica sand using Liquid Polishing Milling Technology (PLMT). The XRF and XRD testing were conducted to determine the composition of silica contained in the silica sand and the level of reactivity of the compound when added into the concrete mix. To determine the effect of nano silica on mortar, then made the specimen with size 50 mm x 50 mm x 50 mm. The composition of mortar is made in two variations, ie by the addition of 3% nano silica and without the addition of nanosilica. To know the mechanical properties of mortar, it is done testing of mortar compressive strength at the age of 28 days. Based on the analysis and evaluation, it is shown that compounds of silica sand in Indonesia, especially Papua reached more than 99% SiO2 and so that the amorphous character of silica sand can be used as a nanomaterial for concrete construction. The results of mechanical tests show that there is an increase of 12% compressive strength of mortar that is added with 3% nano silica.

Properties of dune sand concrete containing coffee waste

Directory of Open Access Journals (Sweden)

Mohamed Guendouz

2018-01-01

Full Text Available In the last years, an increase of coffee beverages consumption has been observed all over the world; and its consumption increases the waste coffee grounds which will become an environmental problems. Recycling of this waste to produce new materials like sand concrete appears as one of the best solutions for reduces the problem of pollution. This work aims to study the possibility of recycling waste coffee grounds (Spent Coffee Grounds (SCG as a fine aggregate by replacing the sand in the manufacturing of dune sand concrete. For this; sand concrete mixes were prepared with substitution of sand with the spent coffee grounds waste at different percentage (0%, 5%, 10%, 15% and 20% by volume of the sand in order to study the influence of this wastes on physical (Workability, bulk density and porosity, mechanical (compressive and flexural strength and Thermal (Thermal conductivity and thermal diffusivity properties of dune sand concrete. The results showed that the use of spent coffee grounds waste as partial replacement of natural sand contributes to reduce workability, bulk density and mechanical strength of sand concrete mixes with an increase on its porosity. However, the thermal characteristics are improved and especially for a level of 15% and 20% of substitution. So, it is possible to obtain an insulating material which can be used in the various types of structural components. This study ensures that reusing of waste coffee grounds in dune sand concrete gives a positive approach to reduce the cost of materials and solve some environmental problems.

Evaluation of crushed aggregate and sand-bentonite mixtures for application to sealing of the final repository for reactor waste

International Nuclear Information System (INIS)

Vaajasaari, M.; Saari, K.; Wang Zhen

1986-09-01

The Industrial Power Company Ltd (TVO) is planning to dispose the low- and intermediate level waste from the reactors of the Olkiluoto Nuclear Power Station into the bedrock of Olkiluoto at a depth of approximately 50-100 meters. In the TVO concept the reactor waste is disposed in silo shaped rock caverns. The bituminized waste is packed into steel drums, which are laid into a concrete silo inside the rock cavern. In this study the properties of sands, crushed aggregate and their mixtures with bentonite are reviewed. The applicability of these materials for use as a buffer on the top of the concrete silo is evaluated. This study is based on earlier experimental studies of the materials mentioned before and available literature. Gas production in the silo after disposal is estimated. General concepts of gas conductivity and gas migration in saturated soil are reviewed. The results of this study suggest that crushed aggregate and sand-bentonite mixtures are possible sealing materials for the silo in concern. But the need for further experimental study of their physical and mechanical properties and the gas migration processes through the saturated barrier is emphasized. A program for testing of these properties is presented

Riddle of the sands

Energy Technology Data Exchange (ETDEWEB)

Rolheiser, P

1998-09-01

A geological model of the Alberta landscape during the period stretching from about 110 million to 100 million years ago during the Cretaceous period when dinosaurs roamed the earth, was sketched. Today, the region contains the Cold Lake oil sands deposit. Imperial Oil began large-scale production at Cold Lake in 1985. The formations within the area are the source of almost half of Imperial Oil`s daily crude oil production and account for one in every 20 barrels of oil produced daily in Canada. The bitumen is produced using cyclic steam stimulation where steam is injected at high pressure into the underground reservoir, fracturing the sandstone and heating the bitumen it holds to thin it so that it can then flow through well bores to the surface. Conventional geological theory suggested that the Cold Lake reservoir was the remains of a prehistoric river delta. In 1994, Imperial Oil established a Cold Lake sequence stratigraphy project to verify this theory. This highly complex project involves volumes of geophysical well-log data from the 2,500 wells at Cold Lake, core samples cut from more than 600 of these wells and microscopic fossilized remains of 100-million-year-old flora extracted from the core samples, and seismic information. The interpreted data helps to create a three-dimensional model of the reservoir`s structure and help define its boundaries. Results have shown that the Cold Lake deposit was created from at least 13 intersecting river beds. Each of the rivers flowed for a few hundred thousand years and deposited sands of varying quality in different layers and patterns. The oil came about 40 million years later after the plant and animal materials containing hydrogen and carbon were broken down by heat and pressure to form oil. 1 fig.

Documenting the global impacts of beach sand mining

Science.gov (United States)

Young, R.; Griffith, A.

2009-04-01

For centuries, beach sand has been mined for use as aggregate in concrete, for heavy minerals, and for construction fill. The global extent and impact of this phenomenon has gone relatively unnoticed by academics, NGOs, and major news sources. Most reports of sand mining activities are found at the very local scale (if the mining is ever documented at all). Yet, sand mining in many localities has resulted in the complete destruction of beach (and related) ecosystems along with severe impacts to coastal protection and tourism. The Program for the Study of Developed Shorelines at Western Carolina University and Beachcare.org have initiated the construction of a global database of beach sand mining activities. The database is being built through a combination of site visits and through the data mining of media resources, peer reviewed papers, and reports from private and governmental entities. Currently, we have documented sand mining in 35 countries on 6 continents representing the removal of millions of cubic meters of sand. Problems extend from Asia where critical infrastructure has been disrupted by sand mining to the Caribbean where policy reform has swiftly followed a highly publicized theft of sand. The Program for the Study of Developed Shorelines recently observed extensive sand mining in Morocco at the regional scale. Tens of kilometers of beach have been stripped of sand and the mining continues southward reducing hope of a thriving tourism-based economy. Problems caused by beach sand mining include: destruction of natural beaches and the ecosystems they protect (e.g. dunes, wetlands), habitat loss for globally important species (e.g. turtles, shorebirds), destruction of nearshore marine ecosystems, increased shoreline erosion rates, reduced protection from storms, tsunamis, and wave events, and economic losses through tourist abandonment and loss of coastal aesthetics. The threats posed by sand mining are made even more critical given the prospect of a

Studies on various characteristics of concrete structures using crushed sand

International Nuclear Information System (INIS)

Mimatsu, Makoto; Sugita, Hideaki; Yonemura, Masataka.

1985-01-01

With the recent advances of construction industry, the demands for concrete, hence for aggregate, are rising. The sand as such is in extreme shortage due to the exhaustion of river sand. Under the situation, the recent trends are for the use of crushed sand, i.e. the artificial sand obtained by crushing rocks, which have advantages of stabilized quality and adequate supplies. In building of nuclear power plants requiring large amounts of concrete, the usage of crushed sand is now unavoidable. The following are described : the situation of aggregate in Kyushu. production method of crushed sand and the quality standards, rocks used for crushed stone and sand and the properties, quality survey on crushed sand and the basic tests, characteristic tests of crushed-stone and -sand mixed concrete, the application of crushed sand in structures of the Sendai Nuclear Power Station. (Mori, K.)

Sedimentological and Scanning Electron Miscroscopic Descriptions of Afowo Oil Sand Deposits, South Western Nigeria

Directory of Open Access Journals (Sweden)

Akinmosin A

2017-12-01

Full Text Available Sedimentological and scanning electron microscopic analyses of some shallow reservoir tar sand samples in parts of Southwestern Nigeria were carried out with the aim of characterizing the reservoir properties in relation to bitumen saturation and recovery efficiency. The production of impregnated tar from the sands requires the reservoir to be of good quality. A total of thirty samples were collected at different localities within the tar sand belt (ten out of these samples were selected for various reservoir quality analyses based on their textural homogeneity. The result of particle size distribution study showed that bulk of the sands is medium – coarse grained and moderately sorted. The grain morphologies are of low to high sphericity with shapes generally sub-angular to sub-rounded, implying that the sands have undergone a fairly long transportation history with depositional energy having a moderate to high velocity. The quartz content was made up of about 96% of the total mineralogical components; the sediments of the Afowo Formation can be described to be mineralogically and texturally stable. The result of the scanning electron microscopy (SEM analysis revealed that the oil sands contained minerals which had been precipitated and occurred as pore filling cement; these minerals include sheet kaolinite, block kaolinite, vermiform kaolinite, pyrite crystals and quartz. The SEM images also showed micro-pores ranging from 0.057µm to 0.446µm and fractures. The study showed that the clay minerals contained in the Afowo reservoir rocks were mainly kaolinite. Kaoline unlike some other clays (e.g Montimorillonite does not swell with water, hence it is not expected to have any negative effects on the reservoir quality, especially during enhanced oil recovery operations.

Salt-water encroachment into aquifers of the Raritan Formation in the Sayreville Area, Middlesex County, New Jersey

Science.gov (United States)

Appel, Charles A.

1962-01-01

The principal sources of ground water in the Sayreville area are the Old Bridge Sand and Farrington Sand Members of the Raritan Formation of Late Cretaceous age. These aquifers yielded about 32.3 mgd (million gallons per day) for public and industrial water supplies in 1958; about 24.5 mgd was withdrawn from the Old Bridge Sand Member.

Semipermeable membrane devices concentrate mixed function oxygenase inducers from oil sands and refinery wastewaters

International Nuclear Information System (INIS)

Parrott, J.L.; Hewitt, L.M.

2002-01-01

The health of fish in the Athabasca River was examined to determine the effects of both natural and anthropogenic oil sands exposure on liver mixed function oxygenase (MFO) enzymes. Semipermeable membrane devices (SPMD) were used to concentrate bioavailable compounds that may result in MFO induction. The SPMDs were used for a period of 2 weeks in the Steepbank River as well as in oil refinery wastewater and intake ponds. They were then tested to see if they induced ethoxyresorufin-O-deethylase (EROD) activity in hepatoma cells, a cell line derived from a liver cancer of a small fish. SPMDs from the wastewater pond contained potent EROD inducers in fish liver cells. SPMDs from the Athabasca River exhibited some EROD inducers, but they were 1/100 as potent as those of the refinery wastewater. The characteristics of MFO inducers from refinery wastewater were different from natural inducers from the oil sands in the Athabasca and Steepbank Rivers. For instance, log Kow was less than 5 for refinery wastewater, but it was greater than 5 for Athabasca River wastewater and from natural oil sands exposure. In the case of the Steepbank River, the pattern of MFO induction was similar to the MFO induction seen in wild fish.The highest MFO inducers were found to be in the area of the mine, suggesting and anthropogenic pollution source. The less potent inducers were in the area of the natural and undisturbed oil sands. Very few inducers were found outside of the oil sands formation

Influence of sand base preparation on properties of chromite moulding sands with sodium silicate hardened with selected methods

Directory of Open Access Journals (Sweden)

Stachowicz M.

2017-03-01

Full Text Available The paper presents a research on the relation between thermal preparation of chromite sand base of moulding sands containing sodium silicate, hardened with selected physical and chemical methods, and structure of the created bonding bridges. Test specimens were prepared of chromite sand - fresh or baked at 950°C for 10 or 24 hours - mixed with 0.5 wt.% of the selected non-modified inorganic binder and, after forming, were hardened with CO2 or liquid esters, dried traditionally or heated with microwaves at 2.45 GHz. It was shown on the grounds of SEM observations that the time of baking the base sand and the hardening method significantly affect structure of the bonding bridges and are correlated with mechanical properties of the moulding sands. It was found that hardening chromite-based moulding mixtures with physical methods is much more favourable than hardening with chemical methods, guaranteeing also more than ten times higher mechanical properties.

The study of heavy metals leaching from waste foundry sands using a one-step extraction

Science.gov (United States)

Bożym, Marta

2017-10-01

There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.). Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni) from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

Experimental perforation of tubing with a hydraulic sand jet

Energy Technology Data Exchange (ETDEWEB)

Semenov, Yu V

1970-01-01

A series of field tests has shown that perforation with a hydraulic sand jet improves the quality of well completion. The sand jet does not crack the cement sheath or the casing, and the perforations are larger and deeper than perforations formed by explosive charges. Fluid circulation during sand jet perforation can safely be stopped for at least 10 min. Water containing a surfactant can be used as a sand carrier. Sand jet perforation allows successful completion of wells cased by 2 tubing strings. Sand jet perforation can be used to clean the borehole well and to remove foreign objects from the well.

Effect of manufactured sand on the durability characteristics of concrete

Directory of Open Access Journals (Sweden)

S. S. SARAVANAN

2016-12-01

Full Text Available Concrete is the most sought after material due to increase in construction activities and infrastructural developments. Availability of natural sand is decreasing thereby increase in the cost of construction. In the present work undertaken, an attempt has been made to give an alternative to natural sand. Optimization of replacement of natural sand with manufactured sand in concrete, durability studies such as water absorption, rapid chloride permeability test, sorptivity, acid resistance, alkaline resistance, impact resistance and abrasion resistance of M40 and M50 grades of concrete have been studied with manufactured sand as fine aggregate and compared the results with the conventional sand concrete. The results shows that there is an increase in the durability properties up to 70 % level of replacements of sand with manufactured sand as fine aggregate and for 100 % use of manufactured sand also gives the better durability than the conventional sand concrete.

Experimental Study on Superfine Sand Concrete Mixed by Double Mixing Technology

OpenAIRE

yuqing zhao

2013-01-01

Traditional concept thought that medium sand and fine sand can be used to mix concrete, superfine sand can not used to mix concrete. This makes the source of superfine sand limited. With the shortage of medium sand and fine sand, it is imperative to exploit the resource of superfine sand. Superfine sand concrete is mixed by means of Double-doped Technology-ultra-fine fly ash and super plasticizer. Primary factor influencing superfine sand concrete strength is studied by orthogonal test, the o...

An analytical model to predict the volume of sand during drilling and production

Directory of Open Access Journals (Sweden)

Raoof Gholami

2016-08-01

Full Text Available Sand production is an undesired phenomenon occurring in unconsolidated formations due to shear failure and hydrodynamic forces. There have been many approaches developed to predict sand production and prevent it by changing drilling or production strategies. However, assumptions involved in these approaches have limited their applications to very specific scenarios. In this paper, an elliptical model based on the borehole shape is presented to predict the volume of sand produced during the drilling and depletion stages of oil and gas reservoirs. A shape factor parameter is introduced to estimate the changes in the geometry of the borehole as a result of shear failure. A carbonate reservoir from the south of Iran with a solid production history is used to show the application of the developed methodology. Deriving mathematical equations for determination of the shape factor based on different failure criteria indicate that the effect of the intermediate principal stress should be taken into account to achieve an accurate result. However, it should be noticed that the methodology presented can only be used when geomechanical parameters are accurately estimated prior to the production stage when using wells and field data.

Sand Dunes with Frost

Science.gov (United States)

2004-01-01

9 May 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a suite of frost-covered sand dunes in the north polar region of Mars in early spring, 2004. The dunes indicate wind transport of sand from left to right (west to east). These landforms are located near 78.1oN, 220.8oW. This picture is illuminated by sunlight from the lower left and covers an area about 3 km (1.9 mi) across.

Quantitative detection of mass concentration of sand-dust storms via wind-profiling radar and analysis of Z- M relationship

Science.gov (United States)

Wang, Minzhong; Ming, Hu; Ruan, Zheng; Gao, Lianhui; Yang, Di

2018-02-01

With the aim to achieve quantitative monitoring of sand-dust storms in real time, wind-profiling radar is applied to monitor and study the process of four sand-dust storms in the Tazhong area of the Taklimakan Desert. Through evaluation and analysis of the spatial-temporal distribution of reflectivity factor, it is found that reflectivity factor ranges from 2 to 18 dBz under sand-dust storm weather. Using echo power spectrum of radar vertical beams, sand-dust particle spectrum and sand-dust mass concentration at the altitude of 600 ˜ 1500 m are retrieved. This study shows that sand-dust mass concentration reaches 700 μg/m3 under blowing sand weather, 2000 μg/m3 under sand-dust storm weather, and 400 μg/m3 under floating dust weather. The following equations are established to represent the relationship between the reflectivity factor and sand-dust mass concentration: Z = 20713.5 M 0.995 under floating dust weather, Z = 22988.3 M 1.006 under blowing sand weather, and Z = 24584.2 M 1.013 under sand-dust storm weather. The retrieval results from this paper are almost consistent with previous monitoring results achieved by former researchers; thus, it is implied that wind-profiling radar can be used as a new reference device to quantitatively monitor sand-dust storms.

Comparative decay of Catellicoccus marimmalium and enterococci in beach sand and seawater.

Science.gov (United States)

Brown, Kendra I; Boehm, Alexandria B

2015-10-15

Most studies characterize microbial source tracking (MST) target performance using sensitivity and specificity metrics. However, it is important to also consider the temporal stability of MST targets in relation to regulated microbial pollutants. Differences among bacterial target stabilities may lead to erroneous conclusions about sources of contamination. The present study evaluates the relative stability of MST targets and fecal indicator organisms using the gull/pigeon-associated Catellicoccus marimammalium (CAT) marker and enterococci (ENT). The decay rates of CAT and ENT measured by culture (cENT) and QPCR (tENT) were compared in sand and seawater laboratory microcosms under environmentally relevant conditions (subject to tidal wetting versus no wetting in sand, and sunlit versus dark conditions in seawater). Bacterial targets were more persistent in beach sand than in seawater with decay rates on the order of 0.01-0.1 per day and 1 to 10 per day, respectively. Targets were more persistent in unwetted compared to wetted sand, and dark compared to sunlit seawater. During the first 8 days of the sand experiment, the decay rate k of CAT was greater than that of cENT. The decay rates of CAT, tENT, and cENT were similar in sand after day 8 and in dark seawater. In sunlit seawater, the decay rates were different between targets with kcENT > kCAT > ktENT. The decay rates presented here are useful for fate and transport models and also inform the use of MST marker concentrations to infer ENT sources in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Compressive Strength of Compacted Clay-Sand Mixes

Directory of Open Access Journals (Sweden)

Faseel Suleman Khan

2014-01-01

Full Text Available The use of sand to improve the strength of natural clays provides a viable alternative for civil infrastructure construction involving earthwork. The main objective of this note was to investigate the compressive strength of compacted clay-sand mixes. A natural clay of high plasticity was mixed with 20% and 40% sand (SP and their compaction and strength properties were determined. Results indicated that the investigated materials exhibited a brittle behaviour on the dry side of optimum and a ductile behaviour on the wet side of optimum. For each material, the compressive strength increased with an increase in density following a power law function. Conversely, the compressive strength increased with decreasing water content of the material following a similar function. Finally, the compressive strength decreased with an increase in sand content because of increased material heterogeneity and loss of sand grains from the sides during shearing.

Formative Evaluation of a Neuroanatomy Course

Science.gov (United States)

Sterret, Patrick R.; Littlefield, John H.

1976-01-01

Student cognitive performance data and affective reactions provided the basis for a formative evaluation of this neuroanatomy curriculum for freshmen medical students. The cerebral hempispheres topic area was marked by poor cognitive performance and low ratings in lecture quality. Videotapes designed to augment neurophysiology also received low…

Controls on the abruptness of gravel-sand transitions

Science.gov (United States)

Venditti, J. G.; Church, M. A.; Lamb, M. P.; Domarad, N.; Rennie, C. D.

2014-12-01

As gravel-bedded rivers fine downstream, they characteristically exhibit an abrupt transition from gravel- to sand-bed. This is the only abrupt transition in grain-size that occurs in the fluvial system and has attracted considerable attention. A number of competing theories have been proposed to account for the abruptness of the transition, including base-level control, attrition of ~10mm gravel to produce sand, and sediment sorting processes. The prevailing theory for the emergence of abrupt transitions is size selective sorting of bimodal sediment wherein gravel deposits due to downstream declining shear stress, fining the bedload until a sand-bed emerges. We explored this hypothesis by examining grain-size, shear stress, gravel mobility and sand suspension thresholds through the gravel-sand transition (GST) of the Fraser River, British Columbia. The Fraser GST is an arrested gravel wedge with patches of gravel downstream of the wedge forming a diffuse extension. There is an abrupt change in bed slope through the transition that leads to an abrupt change in shear stress. The GST, bed-slope change and backwater caused by the ocean are all coincident spatially, which enhances the sharpness of the GST. Interestingly, the bimodal reach of the river occurs downstream of the GST and exhibits no downstream gradients in shear stress, suspended sediment flux, gravel mobility or sand suspension thresholds. This calls into question the prevailing theory for the emergence of an abrupt GST by size selective sorting. We provide evidence, both empirical and theoretical, that suggests the emergence of an abrupt GST is caused by rapid deposition of sand when fine gravel deposits. We argue that the emergence of gravel-sand transitions is a consequence of gravel-bedded rivers adopting a steeper slope than sand-bedded rivers. The abruptness arises because the bed slope required to convey the gravel load fixes the distal location of a terminal gravel wedge, and once the river has

Metakaolin sand – a promising addition for Portland cement

Directory of Open Access Journals (Sweden)

Janotka, I.

2010-06-01

Full Text Available The kaolin sand resource at the Vyšný Petrovec quarry in Slovakia comes to a total of 20 megatonnes. The metakaolin material obtained by heating kaolin sand at 650 ºC contains from 31.5 to 40% (wt metakaolinite, as well as illite, muscovite, quartz and feldspar. The aim of this study was to verify whether this calcined sand (MK1 is a pozzolanic material and characterize the cements and mortars prepared with it. The hydration reactions taking place in the blends were assessed with conduction calorimetry, X-ray diffraction (XRD and differential thermal analysis-thermogravimetry (DTA-TG. Blend and mortar strength development and pore structure were also evaluated. The results obtained showed that this metakaolin sand (MK-1 is a pozzolanic material apt for use as a cement addition and for making mortars.

Las reservas de arena caolínica de la cantera eslovaca de Vyšný Petrovec ascienden a un total de 20 millones de toneladas. El material metacaolínico, que resulta al calentar la arena caolínica a 650 ºC, contiene entre un 31,5 y un 40% de metacaolinita, además de ilita, moscovita, cuarzo y feldespato. El objetivo de este estudio ha sido comprobar que esa arena calcinada es un material puzolánico; así como caracterizar los cementos y morteros preparados con dicha arena (MK-1. La hidratación de las mezclas se evaluó mediante calorimetría de conducción, y difracción de rayos X (DRX y Análisis térmico-diferencial y termogravimétrico (ATD-TG. Se ha evaluado el desarrollo resistente de las mezclas y morteros; así como su estructura porosa. Los resultados obtenidos han demostrado que esa arena metacolínica (MK-1 es un material puzolánico y que podría utilizarse como adición al cemento y en la preparación de morteros.

Updating the FORECAST formative evaluation approach and some implications for ameliorating theory failure, implementation failure, and evaluation failure

Science.gov (United States)

Katz, Jason; Wandersman, Abraham; Goodman, Robert M.; Griffin, Sarah; Wilson, Dawn K.; Schillaci, Michael

2013-01-01

Historically, there has been considerable variability in how formative evaluation has been conceptualized and practiced. FORmative Evaluation Consultation And Systems Technique (FORECAST) is a formative evaluation approach that develops a set of models and processes that can be used across settings and times, while allowing for local adaptations and innovations. FORECAST integrates specific models and tools to improve limitations in program theory, implementation, and evaluation. In the period since its initial use in a federally funded community prevention project in the early 1990s, evaluators have incorporated important formative evaluation innovations into FORECAST, including the integration of feedback loops and proximal outcome evaluation. In addition, FORECAST has been applied in a randomized community research trial. In this article, we describe updates to FORECAST and the implications of FORECAST for ameliorating failures in program theory, implementation, and evaluation. PMID:23624204

Clean and Secure Energy from Domestic Oil Shale and Oil Sands Resources

Energy Technology Data Exchange (ETDEWEB)

Spinti, Jennifer [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Birgenheier, Lauren [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Deo, Milind [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Facelli, Julio [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Hradisky, Michal [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Kelly, Kerry [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Miller, Jan [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); McLennan, John [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Ring, Terry [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Ruple, John [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States); Uchitel, Kirsten [Inst. for Clean and Secure Energy, Salt Lake City, UT (United States)

2015-09-30

(March, 2012); Conjunctive Surface and Groundwater Management in Utah: Implications for Oil Shale and Oil Sands Development (May, 2012); Development of CFD-Based Simulation Tools for In Situ Thermal Processing of Oil Shale/Sands (February, 2012); Core-Based Integrated Sedimentologic, Stratigraphic, and Geochemical Analysis of the Oil Shale Bearing Green River Formation, Uinta Basin, Utah (April, 2011); Atomistic Modeling of Oil Shale Kerogens and Asphaltenes Along with their Interactions with the Inorganic Mineral Matrix (April, 2011); Pore Scale Analysis of Oil Shale/Sands Pyrolysis (March, 2011); Land and Resource Management Issues Relevant to Deploying In-Situ Thermal Technologies (January, 2011); Policy Analysis of Produced Water Issues Associated with In-Situ Thermal Technologies (January, 2011); and Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development (March, 2010)

Stakeholder relations in the oil sands : managing uncertainty

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-05-15

Alberta's oil sands are now at the crossroads of a series of significant and complex global issues that will require careful negotiation by all stakeholders involved in the oil sands industry. This paper discussed methods of managing uncertainty and risk related to the oil sands industry's agenda for the future. Oil sands developers must continue to secure permission from communities and other key stakeholders in order to develop oil sand projects. Stakeholder relations between oil sands operators, First Nations, and Metis Nation communities must ensure that respect is maintained while environmental impacts are minimized and long-term economic benefits are secured for all parties. Environmental non-governmental organizations (ENGOs) must ensure that oil sands resources are developed responsibly, and that environmental standards are maintained. Seven key shifts in stakeholder relations resulting from the recent economic crisis were identified. These included (1) withdrawal from the multi-stakeholder process, (2) increased focus on government to demonstrate policy leadership, (3) a stronger push from ENGOs to express environmental concerns, (4) global lobby and public relations efforts from ENGOs, (5) companies retreating to local community stakeholders, (6) more active demands from First Nations and Metis Nations groups, and (7) companies challenging ENGO campaigns. The study concluded by suggesting that government leadership is needed to clear policy and regulatory frameworks for Canada's oil sands.

Providing floating capabilities in latest-generation sand screens

Energy Technology Data Exchange (ETDEWEB)

Bowen, E.G.; Coronado, M.P. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Baker Hughes, Houston, TX (United States)

2008-10-15

Alternative production methods are needed for the massive reserves located in the bitumen region of Canada's tar sands. The area has over 100 installations of sand screens/slotted liners in both injection and production legs using steam-assisted gravity drainage (SAGD) technology. Multiple wells must be drilled from a single pad because of the sensitive nature of the environment. With significant depths of these wells, a floating sand screen provides assurance that the sand screen will reach the desired depth. Paraffin is generally used to plug the flow access of the screen during installation. This paper discussed a new technology that has been developed to allow for sand screen installations without relying on paraffin wax to withstand differential pressure. The new technology uses a hydro-mechanical valving system incorporated into the screen design to temporarily close off the screen while being run in the hole. The paper described how the technology could provide a reliable, time-saving solution for SAGD installations when floating sand control screens are needed. The paper discussed current technology and its limitations, sand screen installation, screen design for floating applications, and additional applications. It was concluded that this technology solution provides a unique alternative to the methods currently used to install sand screens with SAGD technology in the fast growing Canadian market for bitumen recovery. 2 refs., 5 figs.

Evaluation of the MF/UF Performance for the Reuse of Sand Filter Backwash Water from Drinking Water Treatment Plants

Directory of Open Access Journals (Sweden)

Neda Shirzadi

2015-05-01

Full Text Available The aim of this study was to investigate the application of micro-filtration and ultra-filtration membrane systems in order to improve the physical and microbial quality and the reuse of backwash water from the sand filter units in water treatment plants. The backwash water from filters makes up for 3 to 5 percent of the total water treated, which is disposed in most WTPs. However, the treatment and reuse of the backwash water is more admissible from technical and economic viewpoints, especially in view of the present water scarcity. For the purposes of this study, use was made of membrane modules of micro- and ultra-filters on a pilot scale. The micro-filter employed consisted of a polypropylene membrane module with a porosity of 1 micron in size and a fiberglass module with a porosity of 5 microns. The ultra-filter was made of PVC hollow fiber with a molecular weight of 100,000 Dalton. In order to feed the two pilots, backwash water from a sand filter was collected from one of the WTPs in Tehran. After samples were taken from the backwash water, the physical and microbial removal efficiency was periodically evaluated based on the standard method and the micro-filtration, ultra-filtration, and combined MF/UF processes were compared with respect to their performance. The results indicate that the combined MF/UF process is able to decrease turbidity, MPN, COD, TSS, and Fe with efficiency values of 99.9, 100, 61.5, 99.9 and 98.8 percent, respectively. Overall, the findings confirmed the technical capabilities of this method for the recovery and reuse of the effluent produced in the backwashing mechanism of sand filters in WTPs.

Salt content impact on the unsaturated property of bentonite-sand buffer backfilling materials

Energy Technology Data Exchange (ETDEWEB)

Zhang Ming [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China); Zhang Huyuan, E-mail: p1314lvp@yahoo.com.cn [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China); Jia Lingyan; Cui Suli [Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou 730000 (China)

2012-09-15

Highlights: Black-Right-Pointing-Pointer SWCC and infiltration process of bentonite-sand mixtures is researched. Black-Right-Pointing-Pointer The k{sub u} of bentonite-sand mixtures was evaluated as the buffer backfilling materials. Black-Right-Pointing-Pointer Salt content impacting on the unsaturated property of bentonite-sand materials is small. - Abstract: Bentonite mixed with sand is often considered as possible engineered barrier in deep high-level radioactive waste disposal in China. In the present work, the vapor transfer technique and water infiltration apparatus were used to measure the soil water characteristic curve (SWCC) and unsaturated hydraulic conductivity (k{sub u}) of bentonite-sand mixtures (B/S) effected by salt content. Results show, the water-holding capacity and k{sub u} increase slightly with the concentration of Na{sup +} in pore liquid increasing from 0 g/L to 12 g/L, similar with the solution concentration of Beishan groundwater in China. Salt content in the laboratory produced only one order of magnitude increase in k{sub u}, which is the 'safe' value. The different pore liquid concentrations used in this study led to small differences in thickness of diffuse double layer of bentonite in mixtures, this might explain why some differences have been found in final values of k{sub u}.

Evaluation of the suitability of a plant virus, pepper mild mottle virus, as a surrogate of human enteric viruses for assessment of the efficacy of coagulation-rapid sand filtration to remove those viruses.

Science.gov (United States)

Shirasaki, N; Matsushita, T; Matsui, Y; Yamashita, R

2018-02-01

Here, we evaluated the removal of three representative human enteric viruses - adenovirus (AdV) type 40, coxsackievirus (CV) B5, and hepatitis A virus (HAV) IB - and one surrogate of human caliciviruses - murine norovirus (MNV) type 1 - by coagulation-rapid sand filtration, using water samples from eight water sources for drinking water treatment plants in Japan. The removal ratios of a plant virus (pepper mild mottle virus; PMMoV) and two bacteriophages (MS2 and φX174) were compared with the removal ratios of human enteric viruses to assess the suitability of PMMoV, MS2, and φX174 as surrogates for human enteric viruses. The removal ratios of AdV, CV, HAV, and MNV, evaluated via the real-time polymerase chain reaction (PCR) method, were 0.8-2.5-log 10 when commercially available polyaluminum chloride (PACl, basicity 1.5) and virgin silica sand were used as the coagulant and filter medium, respectively. The type of coagulant affected the virus removal efficiency, but the age of silica sand used in the rapid sand filtration did not. Coagulation-rapid sand filtration with non-sulfated, high-basicity PACls (basicity 2.1 or 2.5) removed viruses more efficiently than the other aluminum-based coagulants. The removal ratios of MS2 were sometimes higher than those of the three human enteric viruses and MNV, whereas the removal ratios of φX174 tended to be smaller than those of the three human enteric viruses and MNV. In contrast, the removal ratios of PMMoV were similar to and strongly correlated with those of the three human enteric viruses and MNV. Thus, PMMoV appears to be a suitable surrogate for human enteric viruses for the assessment of the efficacy of coagulation-rapid sand filtration to remove viruses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Revegetation and management of tailings sand slopes from tar sand extraction: 1978 results

Energy Technology Data Exchange (ETDEWEB)

Rowell, M J

1979-01-01

The results are reported of research into the revegetation of two areas on a steeply sloping dike composed of tailings sand from tar sand extraction at the Great Canadian Oil Sand Limited plant at Fort McMurray, Alberta. One area was seeded with three pasture grasses and two legumes in 1971 after the slope surface had been mixed with peat to a depth of 15 cm. A second area had been amended with peat or peat and overburden and differing rates of fertilizer added. A mix containing nine grasses, four legumes, and oats, as a companion crop, was seeded in July 1976. The objectives of the research were to study methods for the establishment of a stable vegetative cover that would prevent erosion of the slope and, in time, might become a self maintaining unit. Tillage of soil amendments to a depth of 15 cm and 30 cm were compared in promoting deeper rooting and stabilizing of the slope.

The behavior of gaseous iodine in sand

International Nuclear Information System (INIS)

Takahashi, Kanji

1974-01-01

Radioactive iodine gas was passed through 10 different sands collected at rivers and hills. The relation between the amount of the loaded gas and the amount of adsorbed gas was determined at room temperature, 50 -- 60 0 C, and 90 -- 100 0 C under humidity of 2 sand. This amount was about 1 -- 3 times as much as that of monomolecular membrane adsorption, 0.2 -- 0.3 μg/cm 2 . The decrease of adsorption amount that accompanies the increase of humidity is attributable to the decrease of effective surface area of sand due to the presence of water. The transport of iodine in sand was studied by passing gaseous iodine through a glass tubing packed with sand. The distribution in the flow direction of iodine indicated that the ease of desorption depends upon the situation of adsorption. Easily desorbed case was named Henry type adsorption. Hardly desorbed case was named absorption type. Discussion is made on experimental results. (Fukutomi, T.)

Engineering properties of concrete with partial utilization of used foundry sand.

Science.gov (United States)

Manoharan, Thiruvenkitam; Laksmanan, Dhamothiran; Mylsamy, Kaliyannan; Sivakumar, Pandian; Sircar, Anirbid

2018-01-01

Solid wastes generated from manufacturing industries are increasing at an alarming rate and it is consistently increasing. One such industrial solid waste is Used Foundry Sand (UFS). On the other hand, fine aggregates involved in the concrete are generally river sand, which is scarce, high cost and excavation of the river sand that promote environmental degradation. So, there is an urge to find some alternative solution to dispose UFS and to limit the use of river sand. In this research work, river sand was partially replaced by UFS. The percentage replacements were 0, 5, 10, 15, 20 and 25 wt% respectively. Experimental investigations were carried out to evaluate the mechanical, durability and micro-structural properties of M20 concrete at the age of 7, 28 and 91 day. XRD (X-ray Diffraction), EDX (Energy Dispersive X-ray) and optical-microscopic imaging analysis were performed to identify the presence of various compounds and micro cracks in the concrete with UFS. Comparative studies on control mix against trial mix were carried out. It was found that compression strength, flexural strength and modulus of elasticity were approximately constant up to 20 wt% UFS and decreased with further addition. Whereas, split tensile strength was increased after 20 wt% addition but it affects the other properties of concrete. The durability test results showed that the resistance of concrete against abrasion and rapid chloride permeability of the concrete mixture containing UFS up to 20 wt% were almost similar to the values of control mix. The findings suggest that UFS can effectively replace river sand. However, it is recommended that the replacement should not exceed 20 wt%. Copyright © 2017. Published by Elsevier Ltd.

REVIEW OF COASTAL CHARACTERISTICS OF IRON SAND DEPOSITS IN CILACAP CENTRAL JAVA

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Hananto Kurnio

2017-07-01

Full Text Available Mineable iron sand deposits in Cilacap – southern coastal area of Central Java have certain coastal characteristics that need to be studied in order to understand its depositional environment. With the knowledge of such environment, it can be applied to look for other places prospective of iron sand deposits that have the same characteristics especially recently when Cilacap’s deposits were almost depleted. Coastal characteristics of iron sand deposit in Cilacap is shown by successive sandy beach ridges separated by marshy valleys typical of prograded coasts and by dunes of sand elongated parallel to the shore line with elevation varies from 0 m to 15 m above sea level. The iron sand deposit was derived from denudation of andesite and “Old Andesite Formation” enriched in magnetite and ilmenite minerals in the steep elevated and deeply weathered rock hinterlands of Cilacap. High sediment loads of Serayu Basin in the hinterland (3,500-4,500 ton/km2/year; Citarum River basin only 800-1,200 ton/km2/year was causing extensive deposition of iron sand in the coastal zone. Key words: coast, characteristic, iron sand, Cilacap Endapan pasir besi yang dapat ditambang di Cilacap – pesisir selatan Jawa Tengah memiliki karakteristik pantai tertentu yang perlu dikaji agar dapat dipahami lingkungan pengendapannya. Dengan pengetahuan tentang lingkungan pengendapan tersebut, dapat diterapkan untuk mencari daerah-daerah lain prospek endapan pasir besi yang memiliki karakteristik yang sama terutama pada akhir-akhir ini ketika endapan Cilacap akan habis. Karakteristik pantai endapan pasir besi di Cilacap dicirikan oleh urutan pematang pantai berpasir yang dipisahkan oleh lembah-lembah berawa khas pantai maju dan oleh gumuk-gumuk pasir memanjang sejajar dengan garis pantai dengan ketinggian bervariasi dari 0 m hingga 15 m dari muka laut. Endapan pasir besi di daerah ini berasal dari proses denudasi andesit dan “Formasi Andesit

Reservoir attributes of a hydrocarbon-prone sandstone complex: case of the Pab Formation (Late Cretaceous) of Southwest Pakistan

DEFF Research Database (Denmark)

Umar, Muhammad; Khan, Abdul Salam; Kelling, Gilbert

2016-01-01

Links between the architectural elements of major sand bodies and reservoir attributes have been explored in a field study of the hydrocarbon-yielding Late Cretaceous Pab Formation of southwest Pakistan. The lithofacies and facies associations represented in the Pab Formation are the main...... determinants of its reservoir properties. Thus, thick, vertically connected and laterally continuous sand packets have moderate-to-high mean porosities (10–13 %) in fluviodeltaic, shoreface, shelf delta, submarine channel, and fan-lobe facies associations while deeper shelf and basin floor sand bodies yield...... significantly lower porosities (4–6 %). Overall, in the Pab arenites, porosity values increase with increasing grain size and better sorting. The varying sand-shale ratios encountered in different sectors of the Pab outcrop are also petrophysically important: Sequences displaying high ratios yield higher bulk...

Evaluation of microbial biofilm communities from an Alberta oil sands tailings pond.

Science.gov (United States)

Golby, Susanne; Ceri, Howard; Gieg, Lisa M; Chatterjee, Indranil; Marques, Lyriam L R; Turner, Raymond J

2012-01-01

Bitumen extraction from the oil sands of Alberta has resulted in millions of cubic meters of waste stored on-site in tailings ponds. Unique microbial ecology is expected in these ponds, which may be key to their bioremediation potential. We considered that direct culturing of microbes from a tailings sample as biofilms could lead to the recovery of microbial communities that provide good representation of the ecology of the tailings. Culturing of mixed species biofilms in vitro using the Calgary Biofilm Device (CBD) under aerobic, microaerobic, and anaerobic growth conditions was successful both with and without the addition of various growth nutrients. Denaturant gradient gel electrophoresis and 16S rRNA gene pyrotag sequencing revealed that unique mixed biofilm communities were recovered under each incubation condition, with the dominant species belonging to Pseudomonas, Thauera, Hydrogenophaga, Rhodoferax, and Acidovorax. This work used an approach that allowed organisms to grow as a biofilm directly from a sample collected of their environment, and the biofilms cultivated in vitro were representative of the endogenous environmental community. For the first time, representative environmental mixed species biofilms have been isolated and grown under laboratory conditions from an oil sands tailings pond environment and a description of their composition is provided.

Physical and mechanical properties of sand stabilized by cement and natural zeolite

Science.gov (United States)

Salamatpoor, Sina; Jafarian, Yaser; Hajiannia, Alborz

2018-05-01

Loose sands are prone to lose their shear strength when being subjected to static or cyclic loads. To this end, there exist several methods to improve the mechanical properties of sands, but the most crucial and viable approach is the one with the lowest harmful environmental impact both in production and recycling processes. In this regard, zeolite as a natural pozzolanic additive offers an eco-friendly improvement in strength parameters of cemented sandy soils. Thereby, in this study, a series of unconfined compressive strength (UCS) tests are conducted to evaluate the mechanical parameters of the zeolite-cemented sand. The results demonstrate a meaningful increase in the UCS of the treated sand samples for replacement of cement by zeolite at an optimum proportion of 40% in specimens with 14 and 28 days curing time. The effectiveness of the improvement process is demonstrated by the strength improvement ratio which was up to be 128% to 209% for the samples with 14 and 28 days curing time, respectively. With regard to the above results, zeolite can be introduced as a promising cement substitute in stabilization of sandy ground including backfills, roadbed, embankments, and other structural filling systems.

Physiological and biochemical responses of small fish exposed to Athabasca oil sands sediment

International Nuclear Information System (INIS)

Tetrault, G.R.; Environment Canada, Burlington, ON; McMaster, M.E.; Dixon, D.G.; Parrott, J.L.

2002-01-01

A study was conducted to determine the influence of naturally occurring oil sands related compounds on the reproductive function and hepatic responses of fish. Wild fish, both exposed and unexposed to the compounds in question, were collected along with sediments for laboratory testing. The study showed that in vitro gonadal incubation levels of steroid production were lower at the tributary sites within the oil sands deposits. One indicator of exposure to oil sands related compounds (hepatic 7-ethoxyresorufin-O-deethylase activity) was shown to be 5 times higher at the same sites. In addition, slimy sculpin were exposed to sediment samples from the Steepbank River site for 4 to 8 days to evaluate the absorption of the indicator. The indicator in exposed fish was found to be comparable to that measured in fish native to the oil sands area. The study was not capable of predicting an altered ability of gonadal tissue of exposed fish to produce steroid hormones in vitro. It was concluded that future development could compromise the reproductive health of fish in the area

Texture and composition of the Rosa Marina beach sands (Adriatic coast, southern Italy: a sedimentological/ecological approach

Directory of Open Access Journals (Sweden)

Moretti Massimo

2016-06-01

Full Text Available Beach sands from the Rosa Marina locality (Adriatic coast, southern Italy were analysed mainly microscopically in order to trace the source areas of their lithoclastic and bioclastic components. The main cropping out sedimentary units were also studied with the objective to identify the potential source areas of lithoclasts. This allowed to establish how the various rock units contribute to the formation of beach sands. The analysis of the bioclastic components allows to estimate the actual role of organisms regarding the supply of this material to the beach. Identification of taxa that are present in the beach sands as shell fragments or other remains was carried out at the genus or family level. Ecological investigation of the same beach and the recognition of sub-environments (mainly distinguished on the basis of the nature of the substrate and of the water depth was the key topic that allowed to establish the actual source areas of bioclasts in the Rosa Marina beach sands. The sedimentological analysis (including a physical study of the beach and the calculation of some statistical parameters concerning the grain-size curves shows that the Rosa Marina beach is nowadays subject to erosion.

Booming Sand Dunes

Science.gov (United States)

Vriend, Nathalie

"Booming" sand dunes are able to produce low-frequency sound that resembles a pure note from a music instrument. The sound has a dominant audible frequency (70-105 Hz) and several higher harmonics and may be heard from far distances away. A natural or induced avalanche from a slip face of the booming dune triggers the emission that may last for several minutes. There are various references in travel literature to the phenomenon, but to date no scientific explanation covered all field observations. This thesis introduces a new physical model that describes the phenomenon of booming dunes. The waveguide model explains the selection of the booming frequency and the amplification of the sound in terms of constructive interference in a confined geometry. The frequency of the booming is a direct function of the dimensions and velocities in the waveguide. The higher harmonics are related to the higher modes of propagation in the waveguide. The experimental validation includes quantitative field research at the booming dunes of the Mojave Desert and Death Valley National Park. Microphone and geophone recordings of the acoustic and seismic emission show a variation of booming frequency in space and time. The analysis of the sensor data quantifies wave propagation characteristics such as speed, dispersion, and nonlinear effects and allows the distinction between the source mechanism of the booming and the booming itself. The migration of sand dunes results from a complicated interplay between dune building, wind regime, and precipitation. The morphological and morphodynamical characteristics of two field locations are analyzed with various geophysical techniques. Ground-penetrating radar images the subsurface structure of the dunes and reveal a natural, internal layering that is directly related to the history of dune migration. The seismic velocity increases abruptly with depth and gradually increases with downhill position due to compaction. Sand sampling shows local

Oil sands economic impacts Canada : CERI report : backgrounder

International Nuclear Information System (INIS)

2005-09-01

Oil sands production now accounts for 1 out of every 2 barrels of supply in Western Canada. It is anticipated that Alberta's oil sands sector will experience significant growth over the next few decades. This paper provided an outline of the challenges and economic impacts resulting from oil sands development in Canada. Alberta's oil sands reserves are estimated at 175 billion barrels that are deemed economically recoverable using current technology. At current production levels, reserves will sustain production of 2.5 million barrels per day for the next 200 years. A study by the Canadian Energy Research Institute (CERI) has forecast $100 billion in investment for the 2000-2020 period. Numerous companies hold leases and are planning new projects. A number of recent advances in oil sands technology are expected to further reduce costs as development matures. A royalty and tax regime that provides long-term fiscal certainty is a key factor that supports current oil sands growth forecasts. The CERI study has indicated that economic spinoffs from oil sands development relate to employment generated outside of Alberta, and that the largest percentage of government revenue accrues to the federal government. However, development may be constrained because the pace of growth in the sector may exceed underlying infrastructure related to roads, housing and municipal services. An adequate workforce of qualified trades and technical and professional people is also crucial. Several pipeline projects have been proposed to deliver oil sands crudes to new markets over the next decade. It was concluded that the billions of dollars invested in oil sands in Alberta will contribute to the economic prosperity of the entire country. 11 figs

Provenance and recycling of Arabian desert sand

Science.gov (United States)

Garzanti, Eduardo; Vermeesch, Pieter; Andò, Sergio; Vezzoli, Giovanni; Valagussa, Manuel; Allen, Kate; Kadi, Khalid A.; Al-Juboury, Ali I. A.

2013-05-01

This study seeks to determine the ultimate origin of aeolian sand in Arabian deserts by high-resolution petrographic and heavy-mineral techniques combined with zircon U-Pb geochronology. Point-counting is used here as the sole method by which unbiased volume percentages of heavy minerals can be obtained. A comprehensive analysis of river and wadi sands from the Red Sea to the Bitlis-Zagros orogen allowed us to characterize all potential sediment sources, and thus to quantitatively constrain provenance of Arabian dune fields. Two main types of aeolian sand can be distinguished. Quartzose sands with very poor heavy-mineral suites including zircon occupy most of the region comprising the Great Nafud and Rub' al-Khali Sand Seas, and are largely recycled from thick Lower Palaeozoic quartzarenites with very minor first-cycle contributions from Precambrian basement, Mesozoic carbonate rocks, or Neogene basalts. Instead, carbonaticlastic sands with richer lithic and heavy-mineral populations characterize coastal dunes bordering the Arabian Gulf from the Jafurah Sand Sea of Saudi Arabia to the United Arab Emirates. The similarity with detritus carried by the axial Tigris-Euphrates system and by transverse rivers draining carbonate rocks of the Zagros indicates that Arabian coastal dunes largely consist of far-travelled sand, deposited on the exposed floor of the Gulf during Pleistocene lowstands and blown inland by dominant Shamal northerly winds. A dataset of detrital zircon U-Pb ages measured on twelve dune samples and two Lower Palaeozoic sandstones yielded fourteen identical age spectra. The age distributions all show a major Neoproterozoic peak corresponding to the Pan-African magmatic and tectonic events by which the Arabian Shield was assembled, with minor late Palaeoproterozoic and Neoarchean peaks. A similar U-Pb signature characterizes also Jafurah dune sands, suggesting that zircons are dominantly derived from interior Arabia, possibly deflated from the Wadi al

Comparative analysis of fiscal terms for Alberta oil sands and international heavy and conventional oils

International Nuclear Information System (INIS)

Van Meurs, P.

2007-01-01

There are considerable differences between international heavy oil and Alberta oil sands projects, notably the high viscosity of the bitumen in the oil sands reservoirs. The oil sands bitumen do not flow to wells without heating the bitumen, thereby adding to the already high cost of Alberta oil sand operations. This report provided an economic comparison of Alberta oil sands and international heavy oil projects. It also included a brief scoping review to compare with conventional oil regimes. Full exploration costs including the costs of dry holes were allocated to conventional oil operations in order to obtain a proper comparison. This investigation included the costs of dry holes. The report was a follow up to an earlier study released on April 12, 2007 on the preliminary fiscal evaluation of Alberta oil sand terms. The report provided an economic framework and described project selection. It then provided a discussion of production, costs and price data. Four adjusted projects were presented and compared with Alberta. The Venezuelan royalty formula was also discussed. Last, the report provided a detailed fiscal analysis. Comparisons were offered with Cold Lake and Athabasca Mine. A review of some other fiscal systems applicable to conventional oil were also outlined. It was concluded that Alberta oil sands developments are very competitive. It would be possible to modestly increase government revenues, without affecting the international competitive position of Alberta with respect to conventional oil. There is also some possibility to increase the base royalty on the Alberta oil sands without losing competitiveness. tabs., figs

Seabed Gradient Controlling Onshore Transport Rates of Surf Sand during Beach Retreat by Sea Level Rise

Science.gov (United States)

Lee, Hee Jun; Yi, Hi-Il

2018-03-01

A simple relationship is proposed for the onshore transport rates of surf-zone sand to evaluate the beach retreat caused by sea level rise. It suggests that the preservation potential of surf sand is proportional inversely to the seabed gradient during beach retreat. According to this relationship, the erosional remnants of surf sand would be more readily developed on a gentler shelf collectively as transgressive sand sheets. This finding may explain the previous studies regarding the Korean shelves that proposed that the Holocene transgressive sand sheets (HTSS) occur not in the steep eastern shelf but in the gentle western shelf. In line with such presence/absence of the HTSS are the results from some coastal seismic profiles obtained in the present study. The profiles indicate that sand deposits are restricted within the nearshore in the eastern coast, whereas they are persistently traceable to the offshore HTSS in the western coast. Tide is proven to have a negligible influence on the total duration of surf-zone processes. This study may be useful in predicting the consequences of the beach retreat that takes place worldwide as sea levels rise as a result of global warming.

Nuclear energy in the oils sands

International Nuclear Information System (INIS)

Arsenault, J.E.

2014-01-01

The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

Nuclear energy in the oils sands

Energy Technology Data Exchange (ETDEWEB)

Arsenault, J.E.

2014-09-15

The major Canadian oil sands are located in Alberta and Saskatchewan, with most production from the strata along the Athabasca River in Alberta. The economically recoverable oil sands reserves are estimated to be 168 billion barrels which at a current production rate of 1.8 million barrels per day (2012), are projected to last a very long time. Canada has been blessed with vast energy resources which make it potentially energy-independent and able to provide significant exports but there are concerns that their development cannot be managed in a wholly acceptable manner. Comparable concerns have been applied to nuclear energy in the past and in recent times to the oil sands. The technologies associated with these energy sources have always been controversial because they are at the confluence of economics and politics where finding a balance between risk and reward is difficult. So it should be no surprise that when these technologies get linked together in certain proposals their prospect for success is doubly difficult. The possible use of nuclear energy for production of oil from the oil sands dates back to the late 1950s, when an experiment to mine the oil by detonating an underground nuclear device was proposed. It was predicted that the heat and pressure released from such a device would create a large cavern into which oil would flow, and from where it would be pumped to the surface. Almost at the same time, oil sands research using conventional sources of energy had culminated with the development of practical refining processes, essentially those still in use today. These methods require large amounts of heat energy in the form of hot water and steam. In this century nuclear energy was proposed as the source for the heat required by the oil sands production processes. To date neither of these nuclear proposals for oil sands projects have been successful, because the economic and political balance could not be struck. (author)

The study of heavy metals leaching from waste foundry sands using a one-step extraction

Directory of Open Access Journals (Sweden)

Bożym Marta

2017-01-01

Full Text Available There are a number of leaching test which are used to evaluate the effect of foundry waste disposal on the environment (TCLP, SPLP, ASTM at al.. Because the spent foundry sand are usually deposited at the ground level and they have a similar structure to the soil, survey mobility of metals using the same methods seems appropriate. One-step extraction allows for the evaluation of the mobility and bioavailability of metals in soil and waste. Waste foundry sands have been successfully used as a component in manufactured soils in U.S., but concern over metal contamination must be eliminated before considering this direction of use. The study evaluated the leaching of heavy metals (Cd, Pb, Cu, Zn, Cr, Ni from deposited waste foundry sands. The overall, as well as heavy metals were extracted by different type of extractants: H2O, CH3COOH, HCl, EDTA, MgCl2 and NaCOOH. These extractants are most commonly used to study the mobility and bioavailability of metals in soil and waste. In the present study applicable standards and methodology described in the literature in analysis were used. The results allowed to evaluate the bioavailability of metals leached from those wastes.

Sediment Source Fingerprinting of the Lake Urmia Sand Dunes.

Science.gov (United States)

Ahmady-Birgani, Hesam; Agahi, Edris; Ahmadi, Seyed Javad; Erfanian, Mahdi

2018-01-09

Aeolian sand dunes are continuously being discovered in inner dry lands and coastal areas, most of which have been formed over the Last Glacial Maximum. Presently, due to some natural and anthropogenic implications on earth, newly-born sand dunes are quickly emerging. Lake Urmia, the world's second largest permanent hypersaline lake, has started shrinking, vast lands comprising sand dunes over the western shore of the lake have appeared and one question has been playing on the minds of nearby dwellers: where are these sand dunes coming from, What there was not 15 years ago!! In the present study, the determination of the source of the Lake Urmia sand dunes in terms of the quantifying relative contribution of each upstream geomorphological/lithological unit has been performed using geochemical fingerprinting techniques. The findings demonstrate that the alluvial and the fluvial sediments of the western upstream catchment have been transported by water erosion and they accumulated in the lower reaches of the Kahriz River. Wind erosion, as a secondary agent, have carried the aeolian sand-sized sediments to the sand dune area. Hence, the Lake Urmia sand dunes have been originating from simultaneous and joint actions of alluvial, fluvial and aeolian processes.

Evaluation of sorption affinity of cadmium(II) on Haro river sand from aqueous solutions

International Nuclear Information System (INIS)

Hasany, S.M.; Chaudhary, M.H.

2001-01-01

The sorption of Cd(II) on Haro river sand from deionized water is reported. The sorption system obeyed according to the Freundlich and Dubinin-Radushkevich (D-R) isotherms. The Freundlich parameters 1/n = 0.67±0.05 and of A = 1.38±1.14 mmole x g -1 have been ascertained. D-R isotherm yields the values of β = -0.003741±0.000321 kJ 2 x mole -2 , X m = 0.23±0.21 μmole x g -1 and of E = 11.6±0.5 kJ x mole -1 . The influence of common anions and cations on the sorption was examined. Trivalent Bi enhances the sorption whereas Fe, Cr, Al and chromate ions reduce the sorption significantly. Hf(IV) and Ag(I) indicate substantial sorption (61-98%) whereas Gd(III), Re(VII) and Sc(III) show low sorption (<5%). The elements having low sorption can be separated from elements indicating higher sorption using Haro river sand column. (author)

Changes in active eolian sand at northern Coachella Valley, California

Science.gov (United States)

Katra, Itzhak; Scheidt, Stephen; Lancaster, Nicholas

2009-04-01

Climate variability and rapid urbanization have influenced the sand environments in the northern Coachella Valley throughout the late 20th century. This paper addresses changes in the spatial relationships among different sand deposits at northern Coachella Valley between two recent time periods by using satellite data acquired from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The approach employed here, involving multispectral thermal infrared (TIR) data and spectral mixture analysis, has shown that the major sand deposits can be spatially modeled at northern Coachella Valley. The "coarse-grained (quartz-rich) sand" deposit is associated with active eolian sand, and the "mixed sandy soil" and "fine-grained (quartz-rich) sand" deposits are associated with inactive eolian sand. The fractional abundance images showed a significant decrease between 2000 and 2006 in the percentage of active sand in the major depositional area for fluvial sediment, the Whitewater River, but also in two downwind areas: the Whitewater and Willow Hole Reserves. The pattern of the active sand appears to be related to variations in annual precipitation (wet and dry years) and river discharge in the northern Coachella Valley. We suggest here that recent human modifications to the major watercourses that supply sand affect the capability of fluvial deposition areas to restore sediments over time and consequently the responses of the sand transport system to climate change, becoming more sensitive to dry years where areas of active sand may shrink, degrade, and/or stabilize faster. The approach utilized in this study can be advantageous for future monitoring of sand in the northern Coachella Valley for management of these and similar environments.

Namibia : triaxial test on sand

DEFF Research Database (Denmark)

Steenfelt, Jørgen S.; Jacobsen, Kim P.

In connection with a harbour project the friction angle of a fine sand is required. On Friday 13 March 1998 the Danish Geotechnical Institute (DGI) delivered app. 2.5 kg sand for testing at the Geotechnical Engineering Laboratory, Aalborg University. The present Data Report summarises the results...... of two CID, isotropically consolidated, drained triaxial tests carried out according to the instructions in DG1 letter dated 13 March 1998....

Southeast Florida Sediment Assessment and Needs Determination (SAND) Study

Science.gov (United States)

2014-09-01

sand with some shell beds, sandstone , and limestone *Miami Limestone 0 to 80 ft Oolitic limestone, quartz sand, and sandstone Anastasia 0 to 100 ft...Sand, shell beds, marl, calcareous sandstone (coquina/calcarenite) Fort Thompson 0 to 80 ft Silty limestone, silty sand, clayey marl, shell marl...highly- to moderately- weathered quartzose sandstone , and highly-weathered (saprolitic) to moderately-weathered hard limestone. North-south and

Differential effects of a local industrial sand lance fishery on seabird breeding performance

DEFF Research Database (Denmark)

Frederiksen, M.; Jensen, Henrik; Daunt, F.

2008-01-01

fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...... tridactyla), but not for four diving species. Analyzing Kittiwake data from 12 colonies inside and outside the closure zone in a replicated before-after control impact design, we again found that breeding productivity was significantly depressed in the closure zone when the fishery was active, whereas...

Modelling the behavior of an oil saturated sand

International Nuclear Information System (INIS)

Evgin, E.; Altaee, A.; Lord, S.; Konuk, I.

1990-01-01

The experiments carried out in an earlier study show the oil contamination affects the strength and deformation characteristics of a crushed quartz sand. In the present study, a mathematical soil model is used to simulate the mechanical behavior of the same sand. The model parameters are determined for both clean and oil contaminated soil. Simulations are made for the stress-strain behavior of the soil in drained and undrained conventional traixial compression tests. In order to illustrate the effect of changes in the soil properties on the behavior of an engineering structure, a finite element analysis is carried out. In this paper comparative results are presented to show the differences in the behavior of a foundation resting on a clean sand, on an oil contaminated sand, and on a sand contaminated locally

Sand-RAPG combination simulating fertile clayey soil (Part I to IV)

International Nuclear Information System (INIS)

Azzam, R.; El-Hady, O.A.; Lotfy, A.A.; Hegela, M.

1983-01-01

I. Radiation Preparation of RAPG. Sites of co-ordination and reinforcement are dominated in reclaimer ameliorator polymeric gel (RAPG). It is a modified acrylonitrile base multifunction polymer grafted upon a binder of worthless cellulosic agricultural discard. It varies chemically from non-ionic through anionic and cationic to ampholite. The hydroproperty of the gel is similarly controlled. Thus, RAPG can be tailored for any soil texture under various climatic conditions. II. Structure Stability and Maintenance. Sinai dune sand is treated with non-ionic and anionic RAPGs at rates varying from 0.05 to 0.2 wt.%. The stability increased with RAPG anionicity and application rate. The structure formed maintained three cycles of complete destruction and re-formation without significant changes in erosion index. The resistance of sand-RAPG combination to breakdown by tillage, as well as to wind and water erosion, is practically proved. This is in addition to the beneficial changes in bulk density, void ratio and microporosity, which were also achieved. III. Water Preservation. Inshas sandy soil treated by RAPG is compared with fertile clayey soil. The water-holding capacity and retention at different suctions are increased. The available water to plants in treated sand has reached 15 times that of the control, and even exceeded clay by 11%. Water losses by evaporation and leaching as well as deep percolation are all reduced to a minimum. IV. Plantation and Nutritional Status. Pepper seed germination, growth and dry matter are increased in the sand-RAPG combination relative to fertile clayey soil. The optimum rate and anionicity of RAPG are determined. This increases water-use efficiency to twice that of the fertile clayey soil. Macro- and micro-nutrient uptake have also increased. Thus, fertilizer use efficiency is increased by almost three times over that of clay. These factors lead convincingly to the conclusion that RAPG furnishes adequate conditions for sandy soil

Oblique second-order sand transport pathways on an intertidal sand flat in a natural tidal inlet system

DEFF Research Database (Denmark)

Ernstsen, Verner Brandbyge; Lefebvre, Alice; Kroon, Aart

2013-01-01

tide, sand is transported along ESE-oriented pathways across the intertidal flat towards the inner tidal basin. During the late stages of ebb tide, sand is transported in drainage channels (WSWoriented) from the intertidal flat towards the inlet channel. During storm events with winds from SW, wave...

Oil sands supply outlook

International Nuclear Information System (INIS)

Dunbar, R.

2004-01-01

In March 2004, The Canadian Energy Research Institute released a report on the expected future supply from Alberta's oil sands. The report indicates that the future for the already well-established oil sands industry is promising, particularly given the outlook for oil prices. The challenges facing the industry include higher industry supply costs and the need for innovative commercial and technological solutions to address the risks of irregularities and changes in crude oil prices. In 2003, the industry produced 874 thousand barrels per day of synthetic crude oil and unprocessed crude bitumen. This represents 35 per cent of Canada's total oil production. Current production capacity has increased to 1.0 million barrels per day (mbpd) due to new projects. This number may increase to 3.5 mbpd by 2017. Some new projects may be deferred due to the higher raw bitumen and synthetic crude oil supply costs. This presentation provided supply costs for a range of oil sands recovery technologies and production projections under various business scenarios. tabs., figs

Diversity patterns, Leishmania DNA detection, and bloodmeal identification of Phlebotominae sand flies in villages in northern Colombia.

Science.gov (United States)

González, Camila; León, Cielo; Paz, Andrea; López, Marla; Molina, Gisell; Toro, Diana; Ortiz, Mario; Cordovez, Juan Manuel; Atencia, María Claudia; Aguilera, Germán; Tovar, Catalina

2018-01-01

Leishmaniases are neglected tropical diseases exhibiting complex transmission cycles due to the number of parasite species circulating, sand fly species acting as vectors and infected mammals, including humans, which are defined in the New World as accidental hosts. However, current transmission scenarios are changing, and the disease is no longer exclusively related to forested areas but urban transmission foci occur, involving some species of domestic animals as suspected reservoirs. The aim of this study was to determine the transmission cycles in urban environments by evaluating sand fly diversity, detection of Leishmania DNA, and bloodmeal sources through intra and peridomestic collections. The study was carried out in Colombia, in 13 municipalities of Cordoba department, implementing a methodology that could be further used for the evaluation of vector-borne diseases in villages or towns. Our sampling design included 24 houses randomly selected in each of 15 villages distributed in 13 municipalities, which were sampled in two seasons in 2015 and 2016. Sand flies were collected using CDC light traps placed in intra and peridomestic habitats. In addition to the morphological identification, molecular identification through DNA barcodes was also performed. A total of 19,743 sand flies were collected and 13,848 of them (10,268 females and 3,580 males) were used in molecular procedures. Circulation of two known parasite species-Leishmania infantum and Leishmania panamensis was confirmed. Blood source analyses showed that sand flies fed on humans, particularly in the case of the known L. infantum vector, P. evansi; further analyses are advised to evaluate the reservoirs involved in parasite transmission. Our sampling design allowed us to evaluate potential transmission cycles on a department scale, by defining suspected vector species, parasite species present in different municipalities and feeding habits.

The remarkable endemism of moths at White Sands National Monument in New Mexico, USA, with special emphasis on Gelechioidea (Lepidoptera

Directory of Open Access Journals (Sweden)

Eric H. Metzler

2014-03-01

Full Text Available The white sands formation, a snow-white gypsum dunes system, is the world's largest gypsum dune field. White Sands National Monument protects about 40% of the dunes; the dunes formation as it is known today was formed ca. 8,000 years BP. Prior to 8,000 years BP, the area covered by the dunes was a wet cool forest of the last glacial maximum in North America. The dunes were formed as a result of the hypsithermal, a warming and drying period which followed the most recent glacial maximum. The white sands formation is located in south central New Mexico in the Tularosa Basin of southwestern United States. A 10-year study of moths at the dunes was commissioned by the U. S. National Park Service in 2006. Almost immediately species new to science were detected. In the period of 6 years, 30 new species were discovered in the dunes. Several of the new species are white or very pale in color, and are endemic to the dunes. The focus of the 10 year project was modified to emphasize naming the undescribed species which helps the National Park Service catalog and manage the habitats. The data should encourage other researchers to explore the interactions of the animals with the plants and the harsh desert environment, to study DNA and evolution, and to study the rapid adaptation which seems to be occurring.

Exosome Secretion by the Parasitic Protozoan Leishmania within the Sand Fly Midgut

Directory of Open Access Journals (Sweden)

Vanessa Diniz Atayde

2015-11-01

Full Text Available Despite several studies describing the secretion of exosomes by Leishmania in vitro, observation of their formation and release in vivo has remained a major challenge. Herein, we show that Leishmania constitutively secretes exosomes within the lumen of the sand fly midgut through a mechanism homologous to the mammalian pathway. Through egestion experiments, we demonstrate that Leishmania exosomes are part of the sand fly inoculum and are co-egested with the parasite during the insect’s bite, possibly influencing the host infectious process. Indeed, co-inoculation of mice footpads with L. major plus midgut-isolated or in-vitro-isolated L. major exosomes resulted in a significant increase in footpad swelling. Notably, co-injections produced exacerbated lesions through overinduction of inflammatory cytokines, in particular IL-17a. Our data indicate that Leishmania exosomes are an integral part of the parasite’s infectious life cycle, and we propose to add these vesicles to the repertoire of virulence factors associated with vector-transmitted infections.

Sandscape - engaging people in Met Office science through sand sculpture

Science.gov (United States)

Liggins, Felicity; Dowell, Ellen; Wardley, Jamie; Jamieson, Claire

2017-04-01

In 2015, the Met Office's award-winning outreach programme, designed to inspire the next generation of scientists and engineers, delivered one of its most ambitious and creative activities to date. It explored how scientists and artists can come together to create an engaging experience for young people and families. This activity was called Sandscape. Sandscape is an interactive sand sculpture workshop exploring how weather and climate affect our health. Budding sand sculptors are shown how to fashion elaborate structures from sand and water - creating a landscape with bridges, skyscrapers, forests and factories. As they work, participants are encouraged by the scientists delivering the activity to reflect on what makes a healthy city, considering how the natural and built environments influence air quality and circulation and how this impacts our health. Topics discussed include urban heat islands, air pollution and dispersion modelling, pollen forecasting and predicting the wind-borne spread of animal diseases. Each hour long workshop culminates in a dramatic demonstration that uses dry ice to represent clean air circulating from mountains, along rivers and into cities. Here we present an overview of Sandscape, identify the strengths and challenges of such a collaborative, innovative and playful approach to public engagement and share the results of our evaluation. Sandscape was originally supported by the Met Office and the Wellcome Trust, and produced by Einstein's Garden in collaboration with the Met Office, scientists from the University of Exeter and sand sculptors from Sand in Your Eye. It was first presented in Einstein's Garden at Green Man festival 2015, an independent music and arts festival held annually in Wales, and has since been invited to run at the 2015 Bournemouth Arts By the Sea Festival and Teignmouth's TRAIL Sculpture Festival in the summer of 2016.

Understanding Colombian Amazonian white sand forests

NARCIS (Netherlands)

Peñuela-Mora, M.C.

2014-01-01

Although progress has been made in studies on white sand forests in the Amazon, there is still a considerable gap in our knowledge of the unique species composition of white sand forests and their structure and dynamics, especially in Western Amazon. This thesis aims to fill this gap by addressing

Evaluation of a combined modelling-remote sensing method for estimating net radiation in a wetland: a case study in the Nebraska Sand Hills, USA

International Nuclear Information System (INIS)

Goodin, D.G.

1995-01-01

Close-range measurement combined with modelling of incoming radiation is used to evaluate the prospect of remotely-measuring net radiation of a wetland environment located in the Sand Hills of Nebraska. Results indicate that net radiation can be measured with an accuracy comparable to that of conventional instruments. Sources of error are identified and discussed. Possible application of the methodology to satellite remote sensing is considered. (author)

Trajectories of saltating sand particles behind a porous fence

Science.gov (United States)

Zhang, Ning; Lee, Sang Joon; Chen, Ting-Guo

2015-01-01

Trajectories of aeolian sand particles behind a porous wind fence embedded in a simulated atmospheric boundary layer were visualized experimentally, to investigate the shelter effect of the fence on sand saltation. Two sand samples, one collected from a beach (d = 250 μm) and the other from a desert (d = 100 μm), were tested in comparison with the previous studies of a 'no-fence' case. A wind fence (ε = 38.5%) was installed on a flat sand bed filled with each sand sample. A high-speed photography technique and the particle tracking velocimetry (PTV) method were employed to reconstruct the trajectories of particles saltating behind the fence. The collision processes of these sand particles were analyzed, momentum and kinetic energy transfer between saltating particles and ground surface were also investigated. In the wake region, probability density distributions of the impact velocities agree well with the pattern of no-fence case, and can be explained by a log-normal law. The horizontal component of impact velocity for the beach sand is decreased by about 54%, and about 76% for the desert sand. Vertical restitution coefficients of bouncing particles are smaller than 1.0 due to the presence of the wind fence. The saltating particles lose a large proportion of their energy during the collision process. These results illustrate that the porous wind fence effectively abates the further evolution of saltating sand particles.

[Formative evaluation: experience of the Catalonian family and community medicine teaching units].

Science.gov (United States)

Ezquerra Lezcano, Matilde; Bundo Vidiella, Magda; Descarrega Queralt, Ramón; Martín Zurro, Amando; Fores García, Dolores; Fornells Vallès, Josep Maria

2010-04-01

The purpose of this article is to report on the experience in formative evaluation that was carried out in the Catalonian family and community medicine teaching units during the years 2001-2007. This formative evaluation project included the use of several evaluation tools such as, self-listening, video-recording, structured observation of clinical practice, cases by computer and simulated patients. Different resident intakes have participated in the development of the project, as well as their teaching unit tutors and coordinators. This accumulated experience has allowed it to progress into the field of formative evaluation, and to adapt and integrate the activities that were being carried out in a resident portfolio, which in our opinion is the best tool for the formative evaluation of the family medicine resident. Copyright 2009 Elsevier España, S.L. All rights reserved.

The midgut transcriptome of Phlebotomus (Larroussius) perniciosus, a vector of Leishmania infantum: comparison of sugar fed and blood fed sand flies.

Science.gov (United States)

Dostálová, Anna; Votýpka, Jan; Favreau, Amanda J; Barbian, Kent D; Volf, Petr; Valenzuela, Jesus G; Jochim, Ryan C

2011-05-10

Parasite-vector interactions are fundamental in the transmission of vector-borne diseases such as leishmaniasis. Leishmania development in the vector sand fly is confined to the digestive tract, where sand fly midgut molecules interact with the parasites. In this work we sequenced and analyzed two midgut-specific cDNA libraries from sugar fed and blood fed female Phlebotomus perniciosus and compared the transcript expression profiles. A total of 4111 high quality sequences were obtained from the two libraries and assembled into 370 contigs and 1085 singletons. Molecules with putative roles in blood meal digestion, peritrophic matrix formation, immunity and response to oxidative stress were identified, including proteins that were not previously reported in sand flies. These molecules were evaluated relative to other published sand fly transcripts. Comparative analysis of the two libraries revealed transcripts differentially expressed in response to blood feeding. Molecules up regulated by blood feeding include a putative peritrophin (PperPer1), two chymotrypsin-like proteins (PperChym1 and PperChym2), a putative trypsin (PperTryp3) and four putative microvillar proteins (PperMVP1, 2, 4 and 5). Additionally, several transcripts were more abundant in the sugar fed midgut, such as two putative trypsins (PperTryp1 and PperTryp2), a chymotrypsin (PperChym3) and a microvillar protein (PperMVP3). We performed a detailed temporal expression profile analysis of the putative trypsin transcripts using qPCR and confirmed the expression of blood-induced and blood-repressed trypsins. Trypsin expression was measured in Leishmania infantum-infected and uninfected sand flies, which identified the L. infantum-induced down regulation of PperTryp3 at 24 hours post-blood meal. This midgut tissue-specific transcriptome provides insight into the molecules expressed in the midgut of P. perniciosus, an important vector of visceral leishmaniasis in the Old World. Through the comparative

Investment Portfolio Formation Using Multi-criteria evaluation Method MULTIMOORA

Directory of Open Access Journals (Sweden)

Vilius Vaišvilas

2017-06-01

Full Text Available Information that has to be analyzed by investors is complicated and can be interpreted differently by different people, which is why choosing what should be added to the investment portfolio is complicated task. Complexity grows substantially when there are more alternatives to choose from. Multi – criteria evaluation method can be used to choose the best alternatives. Multi–criteria evaluation method MULTIMOORA is not subjective because there is no need to decide ratio of any given variable that is evaluated. MULTIMOORA consists of: formation of ratio system, application of multi – criteria evaluation method as well as investment evaluation and ranking. Purpose of this article is to apply multi – criteria evaluation method MULTIMOORA for the formation and management of investment portfolio from stocks of the Baltic stock market companies. Methods used in the analysis for the article: analysis of scientific literature, statistical analysis, organization and comparison of data, idealization, calculations of MULTIMOORA.

Biodegradable materials as binders for IVth generation moulding sands

OpenAIRE

K. Major-Gabry

2015-01-01

This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions) for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the...

Radiological maps in beach sands along some coastal regions of Turkey

International Nuclear Information System (INIS)

Kucukomeroglu, B.; Karadeniz, A.; Damla, N.; Yesilkanat, C.M.; Cevik, U.

2016-01-01

In the present research, the gamma-emitting radionuclides in beach sands along the coastal regions of the Ordu, Giresun and Trabzon provinces, Turkey have been determined. The natural and anthropogenic radionuclide concentrations of the samples have been measured employing a germanium (HPGe) detector with high resolution and purity. The activity for 238 U, 232 Th, 40 K and 137 Cs of the samples were found to vary in the range from below detection limit (BDL) to 65 Bq·kg −1 , from BDL to 28 Bq·kg −1 , from 9 to 1936 Bq·kg −1 and from BDL to 22 Bq·kg −1 , respectively. The activity concentrations were compared with those in the literature. The associated radiological hazard indices were estimated, and were compared to the internationally recommended values. The radiological map of beach sand in the surveyed area was imaged. The data presented in the study are crucial since they constitute a baseline for the radiological mapping of the region in the future. - Highlights: • The natural and anthropogenic radionuclide concentrations in beach sands were analyzed. • The associated radiological hazard indices were estimated. • The results were evaluated to check the compatibility of national and international values. • The radiological maps of beach sand were produced. • The findings demonstrate that the obtained values were less than the internationally accepted recommended limits.

Understanding the fate of organic micropollutants in sand and granular activated carbon biofiltration systems.

Science.gov (United States)

Paredes, L; Fernandez-Fontaina, E; Lema, J M; Omil, F; Carballa, M

2016-05-01

In this study, sand and granular activated carbon (GAC) biofilters were comparatively assessed as post-treatment technologies of secondary effluents, including the fate of 18 organic micropollutants (OMPs). To determine the contribution of adsorption and biotransformation in OMP removal, four reactors were operated (two biofilters (with biological activity) and two filters (without biological activity)). In addition, the influence of empty bed contact time (EBCT), ranging from 0.012 to 3.2d, and type of secondary effluent (anaerobic and aerobic) were evaluated. Organic matter, ammonium and nitrate were removed in both biofilters, being their adsorption higher on GAC than on sand. According to the behaviour exhibited, OMPs were classified in three different categories: I) biotransformation and high adsorption on GAC and sand (galaxolide, tonalide, celestolide and triclosan), II) biotransformation, high adsorption on GAC but low or null adsorption on sand (ibuprofen, naproxen, fluoxetine, erythromycin, roxythromycim, sulfamethoxazole, trimethoprim, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol), and, III) only adsorption on GAC (carbamazepine, diazepam and diclofenac). No influence of EBCT (in the range tested) and type of secondary effluent was observed in GAC reactors, whereas saturation and kinetic limitation of biotransformation were observed in sand reactors. Taking into account that most of the organic micropollutants studied (around 60%) fell into category II, biotransformation is crucial for the elimination of OMPs in sand biofilters. Copyright © 2016 Elsevier B.V. All rights reserved.

The Canadian oil sands--a sticky future

Energy Technology Data Exchange (ETDEWEB)

Cowtan, S A

1977-01-01

The oil sands have been known for 200 yr but only over the last decade have they been recognized as a potential major energy source for Canada. The study looks at the present GCOS plant, and briefly discusses Canada's future energy requirements and how she might fill those requirements from conventional and nonconventional sources, such as the Frontier areas, oil sands mining, oil sands in situ, and heavy oil. The economics and the future of these sources and the environment necessary for their development are analyzed.

The growth and photosynthesis of Typha in oil sands process affected material and water

Energy Technology Data Exchange (ETDEWEB)

Foote, L. [Alberta Univ., Edmonton, AB (Canada); Hornung, J. [Petro-Canada, Calgary, AB (Canada)

2007-07-01

Aquatic plants such as cattail contribute substantially to the energy flow in wetlands. Since Typha (cattail) plants acquire and cycle carbon and nutrients through wetlands, their growth and recycling of captured nutrients are an important part of natural, healthy wetland ecosystems. Cattail are pervasive and satisfy many of the criteria to be used as indicators of wetland integrity. This study investigated if cattail growth and carbon accrual were influenced by oil sands process materials (OSPM) such as consolidated tailings (CT). The purpose was to facilitate land reclamation initiatives by evaluating the impact that constituents of oil sands process material have on aquatic plant growth. The study was conducted at Suncor's experimental trenches. Six lined basins were used, of which 3 were filled with natural water and 3 were filled with trench water. Cattail were planted in different growth medium combinations, including CT over CT; soil over soil; soil over CT; and soil over sterilized sand. All leaf lengths and widths were measured along with the photosynthesis of the leaves and root and plant biomass at planting and after 2-years growth. A larger leaf area was observed under oil sands process influence, which may indicate increased carbon accrual above ground. Leaf area data suggested that CT affected plants are quite productive. The study also indicated that oil sands affected water may reduce plant fitness, and therefore could influence the overall oil sands reclamation timelines. Conversely, cattail grown in soil capped process affected material had a much larger leaf area compared to those grown in soil capped sand, most likely due to the higher levels of ammonia in process affected material.

Strength and microstructure characteristics of the recycled rubber tire-sand mixtures as lightweight backfill.

Science.gov (United States)

Zhang, Tao; Cai, Guojun; Duan, Weihong

2018-02-01

The disposal of scrap rubber tires has induced critical environmental issue worldwide due to the rapid increase in the number of vehicles. Recycled scrap tires as a construction material in civil engineering have significant environmental benefits from a waste management perspective. A systematic study that deals with strength and microstructure characteristics of the rubber-sand mixtures is initiated, and mechanical response of the mixtures is discussed in this investigation. Experiments were conducted to evaluate the effects of rubber fraction on the basic properties including mass density (ρ), stress-strain characteristics, shear strength, and unconfined compression strength (q u ) of the rubber-sand mixtures. Additionally, scanning electron microscopy (SEM) was carried out to reveal the microstructure characteristics of the mixtures with various rubber fractions. A discussion on the micromechanics of the mixtures also was conducted. This study demonstrates that the ρ, friction angle, and q u decrease linearly with an increase in rubber fraction, whereas shear strain at peak increases. The stress-strain characteristics of the rubber-sand mixtures shift from brittle to ductile as the rubber fraction increase. These changes are attributed to remarkably lower stiffness and higher compressibility of the rubber particle compared with those of the conventional mineral aggregates. With an increase in the rubber fraction, the mechanical response of rubber-sand mixtures exhibits two types: sand-like material and rubber-like material. Rubber particle possesses the capacity to prevent the contacted sand particles from sliding at lower rubber fraction, whereas it transmits the applied loadings as the rubber fraction increased. This outcome reinforces the practicability of using recycled rubber tire-sand mixtures as a lightweight backfill in subbase/base applications.

Environmental isotopes in North African groundwaters; and the Dahna sand-dune study, Saudi Arabia

International Nuclear Information System (INIS)

Sonntag, C.; Thoma, G.; Muennich, K.O.; Dincer, T.; Klitzsch, E.

1980-01-01

I. North Saharian palaeowaters were mainly formed during a long humid period between 50,000 and 20,000 years BP., which was followed by a cool dry period from 20,000 to 14,000 years BP. These palaeowaters show a significant west-east decrease in deuterium and 18 O because of past groundwater formation by local rainfall from the western drift. Sahel zone groundwaters seem to show meridional variation of deuterium and 18 O due to a tropical convective influence. II. A computer model estimate of the alternate play between rainwater infiltration and evaporation in the Dahna sand-dune (near Riyadh, Saudi Arabia) yields a mean annual groundwater recharge of 20 mm annually which agrees with that obtained from bomb tritium vertical profiles of the sand moisture. The model also describes the deuterium and 18 O profiles. (author)

BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS.

Energy Technology Data Exchange (ETDEWEB)

Brigmon, R; Topher Berry, T; Whitney Jones, W; Charles Milliken, C

2008-05-27

BioTiger{trademark} is a unique microbial consortia that resulted from over 8 years of extensive microbiology screening and characterization of samples collected from a century-old Polish waste lagoon. BioTiger{trademark} shows rapid and complete degradation of aliphatic and aromatic hydrocarbons, produces novel surfactants, is tolerant of both chemical and metal toxicity and shows good activity at temperature and pH extremes. Although originally developed and used by the U.S. Department of Energy for bioremediation of oil-contaminated soils, recent efforts have proven that BioTiger{trademark} can also be used to increase hydrocarbon recovery from oil sands. This enhanced ex situ oil recovery process utilizes BioTiger{trademark} to optimize bitumen separation. A floatation test protocol with oil sands from Ft. McMurray, Canada was used for the BioTiger{trademark} evaluation. A comparison of hot water extraction/floatation test of the oil sands performed with BioTiger{trademark} demonstrated a 50% improvement in separation as measured by gravimetric analysis in 4 h and a five-fold increase at 25 hr. Since BioTiger{trademark} performs well at high temperatures and process engineering can enhance and sustain metabolic activity, it can be applied to enhance recovery of hydrocarbons from oil sands or other complex recalcitrant matrices.

Thermoluminescent dosimetric properties of Descalvado sand

International Nuclear Information System (INIS)

Teixeira, M.I.; Caldas, L.V.E.

2006-01-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ( 60 Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

Thermoluminescent dosimetric properties of Descalvado sand

Energy Technology Data Exchange (ETDEWEB)

Teixeira, M.I.; Caldas, L.V.E

2006-07-01

Sand samples proceeding from Descalvado, Sao Paulo, were studied with regard to their dosimetric properties using the thermoluminescence technique (TL) for high doses. These sand samples present steady physical and chemical characteristics to the end items, and they are used in the glass industry and for casting. The TL curves of the samples were obtained after an irradiation at the Gamma-Cell system ({sup 60} Co), of IPEN. The glow curves present two peaks at 80 C and 220 C approximately. Calibration curves were obtained for doses between 50 Gy and 5 kGy. The results indicate that the sand samples can be used for high-doses dosimetry in several areas of applications of ionizing radiation. (Author)

Integrated metagenomic and physiochemical analyses to evaluate the potential role of microbes in the sand filter of a drinking water treatment system.

Directory of Open Access Journals (Sweden)

Yaohui Bai

Full Text Available While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ≈ 10(11 prokaryotes per gram in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90% dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn(2+ and As(3+, might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water.

Integrated metagenomic and physiochemical analyses to evaluate the potential role of microbes in the sand filter of a drinking water treatment system.

Science.gov (United States)

Bai, Yaohui; Liu, Ruiping; Liang, Jinsong; Qu, Jiuhui

2013-01-01

While sand filters are widely used to treat drinking water, the role of sand filter associated microorganisms in water purification has not been extensively studied. In the current investigation, we integrated molecular (based on metagenomic) and physicochemical analyses to elucidate microbial community composition and function in a common sand filter used to treat groundwater for potable consumption. The results revealed that the biofilm developed rapidly within 2 days (reaching ≈ 10(11) prokaryotes per gram) in the sand filter along with abiotic and biotic particulates accumulated in the interstitial spaces. Bacteria (up to 90%) dominated the biofilm microbial community, with Alphaproteobacteria being the most common class. Thaumarchaeota was the sole phylum of Archaea, which might be involved in ammonia oxidation. Function annotation of metagenomic datasets revealed a number of aromatic degradation pathway genes, such as aromatic oxygenase and dehydrogenase genes, in the biofilm, suggesting a significant role for microbes in the breakdown of aromatic compounds in groundwater. Simultaneous nitrification and denitrification pathways were confirmed as the primary routes of nitrogen removal. Dissolved heavy metals in groundwater, e.g. Mn(2+) and As(3+), might be biologically oxidized to insoluble or easily adsorbed compounds and deposited in the sand filter. Our study demonstrated that the role of the microbial community in the sand filter treatment system are critical to effective water purification in drinking water.

Development of a bioassay to assess the toxicity of oil sands sediments to pike (Esox lucius)

Energy Technology Data Exchange (ETDEWEB)

Turcotte, D.; Yuan, H.; Tumber, V.; Parrott, J. [Environment Canada, Ottawa, ON (Canada); Raine, J. [Saskatchewan Univ., Saskatoon, SK (Canada)

2010-07-01

Pike (Esox lucius) are a commercially sought fish species that inhabit the Athabasca River, which flows through the Athabasca oil sands. The fish are exposed to natural sources of bitumen from the McMurray formation. This study was conducted to design and implement a daily-renewal bioassay to assess the toxicity of oil sands to this fish species and to obtain information regarding the development of pike exposed to bitumen. Eggs were collected and fertilized with milt from spawning wild pike captured from Lake Diefenbaker in Saskatchewan. The fertilized eggs were exposed to different concentrations of sediments or culture water only (negative controls) until complete yolk absorption of control fish, approximately 15 days post-hatch. For the rest of the experiment, brine shrimp were fed to the walleye embryos every day after hatching. The developing fish were examined for morphological deformities, survival, hatching success, and changes in weight and length. The research findings indicated that pike is less sensitive than walleye and fathead minnow to the toxicity of oil sands sediments.

Comparison of the sand liquefaction estimated based on codes and practical earthquake damage phenomena

Science.gov (United States)

Fang, Yi; Huang, Yahong

2017-12-01

Conducting sand liquefaction estimated based on codes is the important content of the geotechnical design. However, the result, sometimes, fails to conform to the practical earthquake damages. Based on the damage of Tangshan earthquake and engineering geological conditions, three typical sites are chosen. Moreover, the sand liquefaction probability was evaluated on the three sites by using the method in the Code for Seismic Design of Buildings and the results were compared with the sand liquefaction phenomenon in the earthquake. The result shows that the difference between sand liquefaction estimated based on codes and the practical earthquake damage is mainly attributed to the following two aspects: The primary reasons include disparity between seismic fortification intensity and practical seismic oscillation, changes of groundwater level, thickness of overlying non-liquefied soil layer, local site effect and personal error. Meanwhile, although the judgment methods in the codes exhibit certain universality, they are another reason causing the above difference due to the limitation of basic data and the qualitative anomaly of the judgment formulas.

Aeolian sedimentation in the middle buntsandstein in the eifel north-south depression zone: Summary of the variability of sedimentary processes in a buntsandstein erg as a base for evaluation of the mutual relationships between aeolian sand seas and fluvial river systems in the mid-european buntsandstein

Science.gov (United States)

Mader, Detlef

representing residual sand not having been incorporated into larger dunes of the surrounding sand sea. Damp interdune deposits originate by trapping of loose sand that is blown across a moist playa surface as adhesion ripples and warts. The adhesion structures form both in aeolian sheet sand environments with increasing moisture of the substrate and on fluvial channel bars and stream bottoms with declining dampness during subaerial exposure. Wet interdune deposits originate by settling of suspension fines in periodic shallow lakes between the dunes following heavy ephemeral rainfall or forming by rising ground water table, and by aquatic redeposition of aeolian sand due to washout after atmospheric precipitation and alluvial invasion. Deflationary interdune deposits form by winnowing of the sandy matrix from fluvial sheet or bar conglomerates thereby leaving the dispersed gravel as more or less tightly-packed residual veneer on the degradation surface providing bed armour against further aeolian or aquatic erosion. Aeolian deposition is at the top of the Middle Buntsandstein rather rapidly terminated by fluvial inundation of the erg, erosion and partial resedimentation of dune sands and burial of the more or less degraded aeolian bedforms under a carpet of alluvial deposits. At the beginning of the Upper Buntsandstein, a change to semi-arid climate results in stabilization of emerging overbank plains and channels by palaeosol formation and plant growth thus completely inhibiting further accumulation of aeolian sands. The range of modes of origin of dune sands and interdune deposits, the spatial and temporal variability of their accumulation and preservation and the distribution of water-laid intercalations provide a base for independent evaluation of the dynamics of the aeolian system and its controls as well as for comparative assessment of the behaviour of the aeolian environment and the fluvial milieu in a system of intertonguing sand sea and river belt and of the

A Improved Seabed Surface Sand Sampling Device

Science.gov (United States)

Luo, X.

2017-12-01

In marine geology research it is necessary to obtain a suf fcient quantity of seabed surface samples, while also en- suring that the samples are in their original state. Currently,there are a number of seabed surface sampling devices available, but we fnd it is very diffcult to obtain sand samples using these devices, particularly when dealing with fne sand. Machine-controlled seabed surface sampling devices are also available, but generally unable to dive into deeper regions of water. To obtain larger quantities of seabed surface sand samples in their original states, many researchers have tried to improve upon sampling devices,but these efforts have generally produced ambiguous results, in our opinion.To resolve this issue, we have designed an improved andhighly effective seabed surface sand sampling device that incorporates the strengths of a variety of sampling devices. It is capable of diving into deepwater to obtain fne sand samples and is also suited for use in streams, rivers, lakes and seas with varying levels of depth (up to 100 m). This device can be used for geological mapping, underwater prospecting, geological engineering and ecological, environmental studies in both marine and terrestrial waters.

Mitigating in situ oil sands carbon costs

Energy Technology Data Exchange (ETDEWEB)

Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

2008-10-15

Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

Effects of sea level rise on the formation and drowning of shoreface-connected sand ridges, a model study

NARCIS (Netherlands)

Nnafie, A.|info:eu-repo/dai/nl/37551127X; de Swart, Huib|info:eu-repo/dai/nl/073449725; Calvete, D.|info:eu-repo/dai/nl/304846317; Garnier, R.

2014-01-01

Shoreface-connected sand ridges occur on many storm-dominated inner shelves. These rhythmic features have an along-shelf spacing of 2-10. km, a height of 1-12. m, they evolve on timescales of centuries and they migrate several meters per year. An idealized model is used to study the impact of sea

Electric conductivity for laboratory and field monitoring of induced partial saturation (IPS) in sands

Science.gov (United States)

Kazemiroodsari, Hadi

Liquefaction is loss of shear strength in fully saturated loose sands caused by build-up of excess pore water pressure, during moderate to large earthquakes, leading to catastrophic failures of structures. Currently used liquefaction mitigation measures are often costly and cannot be applied at sites with existing structures. An innovative, practical, and cost effective liquefaction mitigation technique titled "Induced Partial Saturation" (IPS) was developed by researchers at Northeastern University. The IPS technique is based on injection of sodium percarbonate solution into fully saturated liquefaction susceptible sand. Sodium percarbonate dissolves in water and breaks down into sodium and carbonate ions and hydrogen peroxide which generates oxygen gas bubbles. Oxygen gas bubbles become trapped in sand pores and therefore decrease the degree of saturation of the sand, increase the compressibility of the soil, thus reduce its potential for liquefaction. The implementation of IPS required the development and validation of a monitoring and evaluation technique that would help ensure that the sands are indeed partially saturated. This dissertation focuses on this aspect of the IPS research. The monitoring system developed was based on using electric conductivity fundamentals and probes to detect the transport of chemical solution, calculate degree of saturation of sand, and determine the final zone of partial saturation created by IPS. To understand the fundamentals of electric conductivity, laboratory bench-top tests were conducted using electric conductivity probes and small specimens of Ottawa sand. Bench-top tests were used to study rate of generation of gas bubbles due to reaction of sodium percarbonate solution in sand, and to confirm a theory based on which degree of saturation were calculated. In addition to bench-top tests, electric conductivity probes were used in a relatively large sand specimen prepared in a specially manufactured glass tank. IPS was

Physical fertility of degraded acid sands in South-eastern Nigeria ...

African Journals Online (AJOL)

We evaluated the physical fertility of degraded and undegraded acid sands in Akwa Ibom State, South-eastern Nigeria. The soils were similar in texture, being predominantly sandy, averaging 90.1% in degraded and 89.9% in undegraded soil. Bulk density averaged 1.50g/cm3 and 1.45g/cm3, while macropores averaged ...

Effect of water content on the water repellency for hydrophobized sands

Science.gov (United States)

Subedi, S.; Kawamoto, K.; Kuroda, T.; Moldrup, P.; Komatsu, T.

2011-12-01

Alternative earthen covers such as capillary barriers (CBs) and evapotranspirative covers are recognized as useful technical and low-cost solutions for limiting water infiltration and controlling seepage flow at solid waste landfills in semi-arid and arid regions. However, their application to the landfills at wet regions seems to be matter of concern due to loss of their impending capability under high precipitation. One of the possible techniques to enhance the impermeable properties of CBs is to alter soil grain surfaces to be water-repellent by mixing/coating hydrophobic agents (HAs). In order to examine a potential use of model sands hydrophobized with locally available and environmental-friendly HAs such as oleic acid (OA) and stearic acid (SA) for hydrophobic CBs. In the present study, we first characterized the effect of water content on the degree of water repellency (WR) for hydrophobized sands and volcanic ash soil at different depth. Secondly, the time dependency of the contact angle in hydrophobized sands and volcanic ash soils at different water content was evaluated. Further, the effects of hydrophobic organic matter contents on the WR of hydrophobized sands were investigated by horizontal infiltration test. We investigated the degree of WR as functions of volumetric water content (θ) of a volcanic ash soil samples from different depth and water adjusted hydrophobized sand samples with different ratio of HAs by using sessile drop method (SDM). The initial contact angle (αi) measured from SDM decreased gradually with increasing water content in OA and SA coated samples. Measured αi values for volcanic ash soils increased with increasing water content and reached a peak values of 111.7o at θ= 0.325 cm3 cm-3, where-after αi gradually decreased. Each test sample exhibited sharp decrease in contact angle with time at higher water content. Sorptivity values for oleic acid coated samples decreased with increasing HA content and reached the minimum

Dewatering behavior of fine oil sands tailings : A summary of laboratory results

NARCIS (Netherlands)

Yao, Y.; van Tol, A.F.; van Paassen, L.A.; Vardon, P.J.; Sego, D.C.; Wilson, G.W.; Beier, N.A.

2016-01-01

To evaluate the disposal technology for fine oil sands tailings, the appropriate engineering properties of the tailings should be ascertained. A laboratory study was conducted by Delft University of Technology (the Netherlands) on the geotechnical properties and dewatering behavior of the fine oil

Assessment of the capacity of slow sand filtration to eliminate Cryptosporidium oocysts

NARCIS (Netherlands)

Hijnen, W.A.M.; Dullemont, Y.J.; Bosklopper, K.T.G.J.; Schijven, J.F.; Medema, Gerriet Jan

2006-01-01

Decimal Elimination Capacity (DEC) of the slow sand filters of the Dutch drinking water Companies was assessed; first by literature review, followed by evaluation of the removal of environmental spores of sulphite-reducing clostridia (SSRC) and small-sized centric diatoms (SSCD) as surrogates.

Effective Laboratory Method of Chromite Content Estimation in Reclaimed Sands

Directory of Open Access Journals (Sweden)

Ignaszak Z.

2016-09-01

Full Text Available The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid. It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium. The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

Hydrodynamic calculation of a filter sand bed type used in the containment venting systems

International Nuclear Information System (INIS)

Cuevas V, D.; Sainz M, E.; Ortiz V, J.

2015-09-01

The filtered venting of the containment has been adopted in European countries to mitigate the consequences of excess pressure containment during a severe accident. When venting has taken place, the fission products are released directly into the environment, unless a filter on the same path is placed, so that various types of filters are used to trap the fission products. The venting filters of the containment currently installed use different filtration technologies that involve more than one medium. Those using water as the first stage of filtration are called wet systems and are equipped with additional steps to remove water drops and fine aerosols emissions. And even they may also be equipped with an element containing certain absorption means for the filtration of gaseous iodine species. Other designs based on filtration of deep bed as the primary retention step; called dry filters, use filtration media of metal fiber, ceramic or sand to trap aerosols. This paper evaluates the hydraulic characteristics of the filter sand bed type designed by EDF as a candidate to be installed in the containment of BWR Mark II (type of primary containment of the nuclear power plant of Laguna Verde). The evaluation of filter sand bed type was performed using the software package of open source OpenFOAM. Models of each zone of the filtered device were generated and through a series of parametric calculations of computational fluid mechanics relevant hydrodynamic characteristics of the device were obtained, such as pressure drops against mass flow rate and pressure fields and speed at different operating conditions. On the other hand, the model validation of the sand bed filter when comparing the results of experimental tests on a sand column of PITEAS program (1985-1986) against OpenFOAM simulation was realized. The results are very close to those obtained experimentally. (Author)

Differential effects of a local industrial sand lance fishery on seabird breeding performance

DEFF Research Database (Denmark)

Frederiksen, M.; Jensen, Henrik; Daunt, F.

2008-01-01

fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...... or to the fact that only one study colony in the control zone was exposed to high fishery effort within the typical foraging range of Kittiwakes during the breeding season. The strong impact on Kittiwakes, but not on diving species, could result from ( 1) inherently high sensitivity to reduced prey availability...

Microbiological quality assessment of sand and water from three selected beaches of South Coast, São Paulo State, Brazil.

Science.gov (United States)

Pinto, K C; Hachich, E M; Sato, M I Z; Di Bari, M; Coelho, M C L S; Matté, M H; Lamparelli, C C; Razzolini, M T P

2012-01-01

This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of São Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities.

A combined CFD-experimental method for developing an erosion equation for both gas-sand and liquid-sand flows

Science.gov (United States)

Mansouri, Amir

The surface degradation of equipment due to consecutive impacts of abrasive particles carried by fluid flow is called solid particle erosion. Solid particle erosion occurs in many industries including oil and gas. In order to prevent abrupt failures and costly repairs, it is essential to predict the erosion rate and identify the locations of the equipment that are mostly at risk. Computational Fluid Dynamics (CFD) is a powerful tool for predicting the erosion rate. Erosion prediction using CFD analysis includes three steps: (1) obtaining flow solution, (2) particle tracking and calculating the particle impact speed and angle, and (3) relating the particle impact information to mass loss of material through an erosion equation. Erosion equations are commonly generated using dry impingement jet tests (sand-air), since the particle impact speed and angle are assumed not to deviate from conditions in the jet. However, in slurry flows, a wide range of particle impact speeds and angles are produced in a single slurry jet test with liquid and sand particles. In this study, a novel and combined CFD/experimental method for developing an erosion equation in slurry flows is presented. In this method, a CFD analysis is used to characterize the particle impact speed, angle, and impact rate at specific locations on the test sample. Then, the particle impact data are related to the measured erosion depth to achieve an erosion equation from submerged testing. Traditionally, it was assumed that the erosion equation developed based on gas testing can be used for both gas-sand and liquid-sand flows. The erosion equations developed in this work were implemented in a CFD code, and CFD predictions were validated for various test conditions. It was shown that the erosion equation developed based on slurry tests can significantly improve the local thickness loss prediction in slurry flows. Finally, a generalized erosion equation is proposed which can be used to predict the erosion rate in

Big picture thinking in oil sands tailings disposal

Energy Technology Data Exchange (ETDEWEB)

Boswell, J. [Thurber Engineering Ltd., Calgary, AB (Canada)

2010-07-01

This PowerPoint presentation discussed methods of disposing oil sands tailings. Oil sands operators are currently challenged by a variety of legislative and environmental factors concerning the creation and disposal of oil sands tailings. The media has focused on the negative ecological impact of oil sands production, and technical issues are reducing the effect of some mitigation processes. Operators must learn to manage the interface between tailings production and removal, the environment, and public opinion. The successful management of oil sand tailings will include procedures designed to improve reclamation processes, understand environmental laws and regulations, and ensure that the cumulative impacts of tailings are mitigated. Geotechnical investigations, engineering designs and various auditing procedures can be used to develop tailings management plans. Environmental screening and impact assessments can be used to develop sustainable solutions. Public participation and environmental mediation is needed to integrate the public, environmental and technical tailings management strategies. Operators must ensure public accountability for all stakeholders. tabs., figs.

Risk of Mycoplasma bovis transmission from contaminated sand bedding to naive dairy calves.

Science.gov (United States)

Wilson, D J; Justice-Allen, A; Goodell, G; Baldwin, T J; Skirpstunas, R T; Cavender, K B

2011-03-01

The objective of this study was to evaluate the possible transmission of Mycoplasma bovis from positive sand bedding to naïve dairy calves. Twelve preweaned Holstein bull calves were blocked in pairs and randomly assigned as unexposed controls (n=6) bedded with control sand, or exposed calves (n=6) bedded with sand previously positive for M. bovis at a dairy farm. Bedding sand was cultured weekly. Nasal and ear swabs and sera were collected weekly, tracheal swabs were collected monthly, and by the end of the 105-d study, all calves were euthanized (n=10) or died (n=2). Sera were tested for M. bovis-specific antibody. Mycoplasma spp. culture was performed on nasal and ear swabs; culture and a PCR differentiating multiple Mycoplasma spp. were performed on postmortem samples of lung, retropharyngeal lymph node, and trachea from each calf. A complete necropsy also was performed. During 6 wk, mycoplasma concentration in exposed group sand was between 200 and 32,000 cfu/g. All 166 tracheal swabs, nasal and ear swabs, and postmortem tests from all calves were negative for mycoplasma. All 94 sera were negative for M. bovis-specific antibody. No gross pathology suggestive of mycoplasma disease was detected. The probability of mycoplasma detection, if an exposed calf had become infected 4 wk after exposure, ranged between 97 and 99% depending on time of exposure for individual calves. There was no evidence that sand bedding contaminated with M. bovis might serve as a source of transmission to naïve dairy calves. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Western Gas Sands Project. Status report, 1 August-31 August, 1979

Energy Technology Data Exchange (ETDEWEB)

None

1979-01-01

This status report summarizes progress of government-sponsored projects directed toward increasing gas production from the low-permeability gas sands of the western United States. Work on fracture conductivity, rock-fluid interaction, and log evaluation and interpretation techniques continued at Bartlesville. Work commenced on completing, testing and possible hydraulic fracturing of the Rio Blanco Natural Gas Company well No. 397-19-1 and on the evaluation of seismic data for stratigraphic studies of lenticular sands. LLL continued experimental and theoretical work on hydraulic fracturing mechanics and analysis of well test data. LASL worked on developing NMR methods to define fluid saturation, porosity, and permeability of western gas sands at in situ conditions. M.D. Wood, Inc. was involved in design and site preparation for two hydraulic fracture mapping jobs in the Cotton Valley Trend in Texas. Testing and analyses of the borehole seismic system and borehole hydrophone system continued at Sandia. Field tests and related activities for the WGSP progressed as scheduled in August. Cyclic injection of dehydrated natural gas and production in Colorado Interstate Gas Company's Miller No. 1 and Sprague No. 1 wells continued. The Gas Producing Enterprises, Inc. wells, Natural Buttes Units 9, 14, 18 and 20 flowed to sales. The Mitchell Energy Corporation Muse-Duke No. 1 was shut-in for a 15-day pressure buildup test. Hydraulic fracture containment experiments and activities in the multi-frac test series continued at the Nevada Test Site for Sandia Laboratories' mineback program.

Least tern and piping plover nesting at sand pits in Nebraska

Science.gov (United States)

Sidle, John G.; Kirsch, E.M.

1993-01-01

Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

Characterization of sand lenses embedded in tills

DEFF Research Database (Denmark)

Kessler, Timo Christian; Klint, K.E.S.; Nilsson, B.

2012-01-01

Tills dominate large parts of the superficial sediments on the Northern hemisphere. These glacial diamictons are extremely heterogeneous and riddled with fractures and lenses of sand or gravel. The frequency and geometry of sand lenses within tills are strongly linked to glaciodynamic processes...

Sand impaction of the small intestine in eight dogs.

Science.gov (United States)

Moles, A D; McGhite, A; Schaaf, O R; Read, R

2010-01-01

To describe signalment, clinical findings, imaging and treatment of intestinal sand impaction in the dog. Medical records of dogs with radiographic evidence of small intestinal sand impaction were reviewed. Sand impaction resulting in small intestinal obstruction was diagnosed in eight dogs. All dogs presented with signs of vomiting. Other clinical signs included anorexia, lethargy and abdominal pain. Radiographs confirmed the presence of radio-opaque material consistent with sand causing distension of the terminal small intestine in all dogs. Four dogs were treated surgically for their impaction and four dogs were managed medically. Seven of the eight dogs survived. Both medical and surgical management of intestinal sand impaction in the dog can be effective and both afford a good prognosis for recovery.

Reuse of waste foundry sand through interaction with sodium silicate binder

International Nuclear Information System (INIS)

Souza, J.C.; Chinelatto, A.S.A.; Chinelatto, A.L.; Oliveira, I.L.

2012-01-01

Green sand molds are used in metal casting process. However, after heating, activated bentonite present in green sand lose the binding properties, and part of the foundry sand has to be discarded from the process. The ABNT NBR 15.984/2011 establishes the management of waste foundry sand (WFS) avoiding disposal in landfills. The objective of this work was to investigate the possibility of reusing the WFS from the study of their interaction with sodium silicate binder. Studies with silica sand and new green sand was performed to compare the results obtained with the WFS. The characterizations of the samples were performed by measures the compressive strength, X-ray diffraction, optical microscopy and scanning electron microscopy. The results showed that there is interaction of the sodium silicate with the WFS as well as with the silica sand and green sand. (author)

Geotechnical properties of crude oil contaminated sand

International Nuclear Information System (INIS)

Puri, V.K.; Das, B.M.; Cook, E.E.; Shin, E.C.

1994-01-01

Contamination of soil due to an oil spill influences its subsequent engineering behavior. An investigation was conducted to study the effect of crude oil contamination on compaction characteristics, shear strength, one-dimensional compression, and coefficient of permeability. Water permeability was also determined by using commercial grade motor oils as contaminants. The test results indicate that the compaction characteristics are influenced by oil contamination. The angle of internal friction of sand (based on total stress condition) decreases due to presence of oil within the pore spaces in sand. One dimensional compression characteristics of sand are significantly influenced by oil contamination resulting in a decrease in the value of constrained modulus with increase in the degree of oil contamination compared to the case of dry sand. Water permeability was observed to be a function of the initial viscosity and the degree of saturation due to the contaminating oil

Sanding dust from nanoparticle-containing paints: Physical characterisation

International Nuclear Information System (INIS)

Koponen, I K; Jensen, K A; Schneider, T

2009-01-01

Increasing use of nanoparticles in different industrial applications has raised a new potential health risk to the workers as well as to the consumers. This study investigates the particle size distributions of sanding dust released from paints produced with and without engineered nanoparticles. Dust emissions from sanding painted plates were found to consist of five size modes; three modes under 1 μm and two modes around 1 and 2 μm. We observed that the sander was the only source of particles smaller than 50 nm and they dominated the number concentration spectra. Mass and surface area spectra were dominated by the 1 and 2 μm modes. Addition of nanoparticles caused only minor changes in the geometric mean diameters of the particle modes generated during sanding of two paints doped with 17 nm TiO2 and 95 nm Carbon Black nanoparticles as compared to the size modes generated during sanding a conventional reference paint. However, the number concentrations in the different size modes varied considerably in between the two NP-doped paints and the reference paint. Therefore, from a physical point of view, there may be a difference in the exposure risk during sanding surfaces covered with nanoparticle-based paints as compared to sanding conventional paints.

In vitro evaluation of the toxic effects and endocrine disrupting potential of oil sands processed water and naphthenic acids

Energy Technology Data Exchange (ETDEWEB)

Zhang, X.; Wiseman, S.; Higley, E.; Jones, P.D.; Hecker, M.; Giesy, J.P. [Saskatchewan Univ., Saskatoon, SK (Canada); Gamel El Din, M.; Martin, J.W. [Alberta Univ., Edmonton, AB (Canada)

2009-07-01

Naphthenic acids (NAs) are the primary toxic constituents of oil sands process-affected waters (OSPW). This presentation reported on a series of in vitro studies that were initiated to evaluate potential endocrine modulating effects of OSPW and their constituent NAs. The H295R steroidogenesis bioassay was used to examine the impact of OSPW and NA on 52 steroidogenesis. In particular, dose-response and time course studies were conducted to evaluate the impact of OSPW and NAs on testosterone and estradiol production. Aromatase activity and transcript abundance of the key 11 steroidogenic enzymes were also quantified to complement analysis of hormone levels. The MVLN trans-activation assay was used to test the estrogenicity/anti-estrogenicity of OSPW and NAs. In vitro cell viability and apoptosis (live-dead) caused by OSPW and NAs was quantified by the MTS reduction and caspase-3/7 activity in H295R and MVLN cells.

Are light traps baited with kairomones effective in the capture of Lutzomyia longipalpis and Lutzomyia intermedia? An evaluation of synthetic human odor as an attractant for phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae).

Science.gov (United States)

Andrade, Andrey J; Andrade, Mateus R; Dias, Edelberto S; Pinto, Mara C; Eiras, Alvaro E

2008-06-01

Phlebotomine sand flies are often captured with human bait and/or light traps, either with or without an animal bait. More recently, synthetic attractants have been used as bait in traps to improve the capture of phlebotomine sand flies as well as other insects of medical and veterinary importance. The aim of the present study was to evaluate the effects of the kairomone 1-octen-3-ol (octenol) and the synthetic human odor BG-Mesh Lure (BGML--lactic acid, caproic acid and ammonia) baited in modified CDC light traps on the capture of phlebotomine sand flies. The experiments followed the 5x5 Latin square design. Among the species caught, Lutzomyia intermedia apparently presented a dose-dependent response to octenol. The response obtained with the BGML, alone or in combination with octenol (5 mg/h), indicated some degree of attractiveness of these baits to different phlebotomine sand fly species. Octenol seems to be more attractive to L. intermedia than to Lutzomyia longipalpis, while the BGML presented a higher success in capturing L. longipalpis. When the components of the BGML were used separately, there was no increase in catching the female of L. intermedia. Apparently, there was no synergistic effect between the octenol and the BGML. In conclusion, the octenol and the BGML were demonstrated to be possible baits to attract some phlebotomine sand fly species.

Engineering report on drilling in the Sand Wash Basin intermediate grade project

International Nuclear Information System (INIS)

1980-09-01

The Sand Wash Basin Intermediate Grade Drilling Project was conducted by Bendix Field Engineering Corporation in support of the US Department of Energy (DOE) National Uranium Resource Evaluation (NURE) program. This project consisted of 19 drill holes ranging in depth from 275 to 1220 feet (83.9 to 372.1 m). A total of 11,569 feet (3528.5 m) was rotary drilled and 130 feet (39.7 m) were cored for a total of 11,699 feet (3568.2 m) for the project. The project objective was to provide comprehensive subsurface geologic data relevant to Intermediate Grade uranium mineralization of the Browns Park Formation in the Sugar Loaf Peak Site A, and the Little Juniper Mountain Site B areas. All boreholes are located on the USGS Juniper Hot Springs and the Lay 7.5-Minute Series (Topographic) Quadrangles. The project began May 2, 1980; drilling was completed June 3, 1980. Site restoration and clean up was initiated immediately upon the completion of the last borehole and was completed June 8, 1980

[Preliminary Study of Lonicera hypoglauca on Germination Conditions of Sand Culture Seeds and Sterilization Method of Sand Culture Seedling Sterilization].

Science.gov (United States)

Tan, Mu-xiu; Zeng, Wen-wen; Wei, Peng-xiao; Mo, Qiao-cheng; Pu, Zu-ning; Cen, Xiu-fen; Shi, Feng-hua

2015-05-01

To explore the germination conditions of Lonicera hypoglauca sand culture seeds and the effects of sand culture seedlings sterilization. 0.1% HgCl2 with different sterilization time, different illumination time and temperature culture condition were adopted to study the germination conditions of sand culture seeds. Different sterilization treatments and different hardening-seedling days were used to test the sterilization effect of sand culture seedlings. The sterilization effect of the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min on Lonicera hypoglauca seeds was the optimum,with the average pollution rate of 15.56%, and the average germination rate reached 51.11%. The combination of varied temperature-room temperature under light for 12 h/d was the best, with the average germination rate peaked at 75.49%, and the average germination potential reached 68.36%. The treatment of detergent liquor scrub-tap water wash on the part above the hypocotyl, which was sand cultured under the opening condition and had no root, showed the best sterilization effect, with the average pollution rate was zero, and the average survival rate peaked at 100.00%. The sterilization effect of sand culture seedlings, which was disinfected after cleaning by detergent liquor scrub-tap water wash after hardening-seeding for 30 days, was the best, with the average pollution rate of 50.00%, and the average survival rate of 100.00%. The best sterilization effect is the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min; Lighting for 12 h/d of varied temperature-room temperature is regarded as the optimum culture condition. The treatment of detergent liquor scrub-tap water wash treatment on the part above the hypocotyl,which is sand cultured under the opening condition and had no root, shows the best sterilization effect. For the sand culture seedlings, before inoculated in subculture medium, should be hardening-seedling for some days and sterilized after detergent liquor scrub-tap water wash.

Understanding the fate of organic micropollutants in sand and granular activated carbon biofiltration systems

Energy Technology Data Exchange (ETDEWEB)

Paredes, L., E-mail: lidia.paredes@usc.es; Fernandez-Fontaina, E., E-mail: eduardo.fernandez.fontaina@usc.es; Lema, J.M., E-mail: juan.lema@usc.es; Omil, F., E-mail: francisco.omil@usc.es; Carballa, M., E-mail: marta.carballa@usc.es

2016-05-01

In this study, sand and granular activated carbon (GAC) biofilters were comparatively assessed as post-treatment technologies of secondary effluents, including the fate of 18 organic micropollutants (OMPs). To determine the contribution of adsorption and biotransformation in OMP removal, four reactors were operated (two biofilters (with biological activity) and two filters (without biological activity)). In addition, the influence of empty bed contact time (EBCT), ranging from 0.012 to 3.2 d, and type of secondary effluent (anaerobic and aerobic) were evaluated. Organic matter, ammonium and nitrate were removed in both biofilters, being their adsorption higher on GAC than on sand. According to the behaviour exhibited, OMPs were classified in three different categories: I) biotransformation and high adsorption on GAC and sand (galaxolide, tonalide, celestolide and triclosan), II) biotransformation, high adsorption on GAC but low or null adsorption on sand (ibuprofen, naproxen, fluoxetine, erythromycin, roxythromycim, sulfamethoxazole, trimethoprim, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol), and, III) only adsorption on GAC (carbamazepine, diazepam and diclofenac). No influence of EBCT (in the range tested) and type of secondary effluent was observed in GAC reactors, whereas saturation and kinetic limitation of biotransformation were observed in sand reactors. Taking into account that most of the organic micropollutants studied (around 60%) fell into category II, biotransformation is crucial for the elimination of OMPs in sand biofilters. - Highlights: • OMP removal was comparatively assessed in sand and GAC biofilters. • The contribution of adsorption and biotransformation in OMP removal was identified. • The filtering material did not affect the biological activities in biofilters. • There is no direct correlation between EBCT and OMP removal in biofilters. • The type of secondary effluent determines the lifespan of filtering

Understanding the fate of organic micropollutants in sand and granular activated carbon biofiltration systems

International Nuclear Information System (INIS)

Paredes, L.; Fernandez-Fontaina, E.; Lema, J.M.; Omil, F.; Carballa, M.

2016-01-01

In this study, sand and granular activated carbon (GAC) biofilters were comparatively assessed as post-treatment technologies of secondary effluents, including the fate of 18 organic micropollutants (OMPs). To determine the contribution of adsorption and biotransformation in OMP removal, four reactors were operated (two biofilters (with biological activity) and two filters (without biological activity)). In addition, the influence of empty bed contact time (EBCT), ranging from 0.012 to 3.2 d, and type of secondary effluent (anaerobic and aerobic) were evaluated. Organic matter, ammonium and nitrate were removed in both biofilters, being their adsorption higher on GAC than on sand. According to the behaviour exhibited, OMPs were classified in three different categories: I) biotransformation and high adsorption on GAC and sand (galaxolide, tonalide, celestolide and triclosan), II) biotransformation, high adsorption on GAC but low or null adsorption on sand (ibuprofen, naproxen, fluoxetine, erythromycin, roxythromycim, sulfamethoxazole, trimethoprim, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol), and, III) only adsorption on GAC (carbamazepine, diazepam and diclofenac). No influence of EBCT (in the range tested) and type of secondary effluent was observed in GAC reactors, whereas saturation and kinetic limitation of biotransformation were observed in sand reactors. Taking into account that most of the organic micropollutants studied (around 60%) fell into category II, biotransformation is crucial for the elimination of OMPs in sand biofilters. - Highlights: • OMP removal was comparatively assessed in sand and GAC biofilters. • The contribution of adsorption and biotransformation in OMP removal was identified. • The filtering material did not affect the biological activities in biofilters. • There is no direct correlation between EBCT and OMP removal in biofilters. • The type of secondary effluent determines the lifespan of filtering

Strength and Compaction Analysis of Sand-Bentonite-Coal Ash Mixes

Science.gov (United States)

Sobti, Jaskiran; Singh, Sanjay Kumar

2017-08-01

This paper deals with the strength and compaction characteristics of sand-bentonite-coal ash mixes prepared by varying percentages of sand, bentonite and coal ash to be used in cutoff walls and as a liner or cover material in landfills. The maximum dry density (MDD) and optimum moisture content (OMC) of sand-bentonite mixes and sand-bentonite-coal ash mixes were determined by conducting the standard proctor test. Also, the strength and stiffness characteristics of soil mixes were furnished using unconfined compressive strength test. The results of the study reveal influence of varying percentages of coal ash and bentonite on the compaction characteristics of the sand-bentonite-coal ash mixes. Also, validation of a statistical analysis of the correlations between maximum dry density (MDD), optimum moisture content (OMC) and Specific Gravity (G) was done using the experimental results. The experimental results obtained for sand-bentonite, sand-bentonite-ash and coal ash-bentonite mixes very well satisfied the statistical relations between MDD, OMC and G with a maximum error in the estimate of MDD being within ±1 kN/m3. The coefficient of determination (R2) ranged from 0.95 to 0.967 in case of sand-bentonite-ash mixes. However, for sand-bentonite mixes, the R2 values are low and varied from 0.48 to 0.56.

Sand filter clogging by septic tank effluent.

Science.gov (United States)

Spychała, M; Błazejewski, R

2003-01-01

The aim of this study was to characterise conditions and factors affecting fine sand clogging by septic tank effluent on the basis of physical modelling. The physical model consisted of 12 sand columns dosed with sewage from one household (5 persons), preliminary treated in a septic tank. Hydraulic loadings of the sand filters were equal to 82 mm/d. The mean discharge from sand columns, measured as the effluent volume collected during 10 minutes, decreased significantly over the experiment period from 34 cm3/min in August 2000 to 20 cm3/min in August 2001 at the same temperature of about 20 degrees C. First the columns clogged almost completely after 480 days in December 2001, however six columns had remained unclogged till the end of the experiment (March 2002). The temperature had a significant impact on hydraulic conductivity. A vertical distribution of accumulated mass and biomass was investigated in partly clogged sand. Microscopic survey of the clogging layer showed a presence of live micro-organisms, residuals of dead micro-organisms, particularly pieces of small animal armour and many fibres. These particles accelerated the accumulation of solids in the upper clogging layer. The study indicated that temperature impact on the filter hydraulic conductivity was more significant for biological activity, than for sewage viscosity.

Gravel Mobility in a High Sand Content Riverbed

Science.gov (United States)

Haschenburger, J. K.

2017-12-01

In sand-gravel channels, sand may modify gravel transport by changing conditions of entrainment and promoting longer displacements or gravel may inhibit sand transport if concentrated into distinct deposits, which restrict sand supply with consequences for migrating bedform size or form. This study reports on gravel mobility in the lower San Antonio River, Texas, where gravel content in the bed material ranges from about 1% to more than 20%. Sediment transport observations were collected at three U.S. Geological Survey gauging stations by deploying a Helley-Smith sampler with a 0.2 mm mesh bag from which transport rates and mobile grain sizes were determined. The flow rates sampled translate into an annual exceedance expectation from 0.2% to 98%. Gravel transport rates are generally two orders of magnitude smaller than the rates of sand transport. However, the finest gravels are transported at rates on the same order of magnitude as the coarsest sands. At all sites, the 2 and 2.8 mm fractions are transported at the lowest flow rate sampled, suggesting mobility for at least 38% to as much as 98% of the year. Fractions as large as 8 mm are mobilized at flow rates that are expected between 25% and 53% of the year. The largest fractions captured in the sampling (16 to 32 mm) require flows closer to bankfull conditions that occur no more than 0.8% of the year. Results document that some gravel sizes can be frequently transported in low gradient riverbeds with high sand content.

Adsorption of petroleum resins and asphaltenes onto reservoir rock sands studied by near infrared (NIR) spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Syunyaev, R.Z.; Balabin, R.M. [Russian State Univ. of Oil and Gas, Moscow (Russian Federation). Dept. of Physics; Akhatov, I.S. [North Dakota State Univ., Fargo, ND (United States). Dept. of Mechanical Engineering and Center for Nanoscale Science and Engineering

2008-07-01

The presence of asphaltene and resin in crude oil is known to cause well bore plugging and pipeline deposition; stabilization of water/oil emulsions; sedimentation and plugging during crude oil storage; adsorption on refining equipment and coke formation. Kinetic and thermodynamic parameters of adsorption are also known to influence wettability and the capillary number. In this study, adsorption parameters of petroleum resins and asphaltenes were evaluated by Near Infrared (NIR) spectroscopy. Fractioned quartz, dolomite, mica and kaolinite sands were used as adsorbent. The particle size distribution was evaluated using an optical microscope. Porosity and permeability of each fraction were designed and benzene was used as the solvent. Various approaches for calibrating NIR spectra-macromolecules concentration were discussed. In this study, the partial least squares (PLS) regression method was used and the Langmuir model was chosen for experimental data fitting. Kinetic and isothermic data was used to evaluate the maximal adsorbed mass density, the equilibrium constant of adsorption, and the rate constants of adsorption and desorption. The rate constants of resins adsorption and desorption depended on the concentration. A numerical algorithm was developed to estimate the diffusion coefficient and relaxation time from the experimental data.

Scour at Vertical Piles in Sand-Clay Mixtures under Waves

DEFF Research Database (Denmark)

Dey, Subhasish; Helkjær, Anders; Sumer, B. Mutlu

2011-01-01

Marine sediments often contain sand-clay mixtures in widely varying proportions. This study presents the results of equilibrium scour and time variation of scour depths at circular piles embedded vertically in clay alone and sand-clay mixed beds under waves. Experiments were conducted in a wave...... flume with different proportions of sand-clay mixtures as bed sediments. Test results for the cases of steady current and sand alone under waves are used as references. The equilibrium scour depth reduces with an increase in clay proportion n (by weight) in a sand-clay mixture. Interestingly, the scour...

Frac sand in the United States: a geological and industry overview

Science.gov (United States)

Benson, Mary Ellen; Wilson, Anna B.; Bleiwas, Donald I.

2015-01-01

A new mineral rush is underway in the upper Midwest of the United States, especially in Wisconsin and Minnesota, for deposits of high-quality frac sand that the mining industry calls “Northern White” sand or “Ottawa” sand. Frac sand is a specialized type of sand that is added to fracking fluids that are injected into unconventional oil and gas wells during hydraulic fracturing (fracking or hydrofracking), a process that enhances petroleum extraction from tight (low permeability) reservoirs. Frac sand consists of natural sand grains with strict mineralogical and textural specifications that act as a proppant (keeping induced fractures open), extending the time of release and the flow rate of hydrocarbons from fractured rock surfaces in contact with the wellbore.

ZZ DOSCROS, Neutron Cross-Section Library for Spectra Unfolding and Integral Parameter Evaluation

International Nuclear Information System (INIS)

Zijp, Willem L.; Nolthenius, Henk J.; Rieffe, Henk Ch.

1987-01-01

1 - Description of problem or function: Format: SAND-II; Number of groups: 640 fine group cross section values; Nuclides: Li, B, F, Na, Mg, Al, S, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Nb, Mo, Rh, Pd, Ag, In, Sb, I, Cs, La, Eu, Sm, Dy, Lu, Ta, W, Re, Au, Th, U, Np, Pu. Origin: ENDF/B-V mainly, ENDF/B-IV, INDL/V. This library forms in combination with the DAMSIG81 library a convenient source of evaluated energy dependent cross section sets which may be used in the determination of neutron spectra by means of adjustment (or unfolding) procedures or which can be used for the determination of integral parameters (such as damage-to-activation ratio) useful in characterising the neutron spectra. The energy dependent fine group cross section data are presented in a 640 group structure of the SAND-II type. This group structure has 45 energy groups per energy decade below 1 MeV and a group width of 100 KeV above 1 MeV. The total energy span of this group structure is from 10 -10 MeV to 20 MeV. The library has the SAND-II format, which implies that a special part of the library has to contain cover cross section data sets. These cross section data sets are required in the SAND-II program for taking into account the influence of special detector surroundings which may be used during an irradiation. 2 - Method of solution: The selection of the reactions from the evaluated nuclear data libraries was determined by various properties of the reactions for neutron metrology. For this reason all the well- known reactions of the ENDF/B-V dosimetry file are included but these data are supplemented with cross section sets for less well known metrology reactions which may become of interest

On shelterbelt design for combating sand invasion.

NARCIS (Netherlands)

Mohammed, A.E.; Stigter, C.J.; Adam, H.S.

1996-01-01

After a review of the scarce literature on using trees against sand encroachment, a quantitative experiment with a wide shelterbelt to combat sand invasion is reported on. Experimental work was carried out at the northwestern border of the Gezira Scheme (Sudan), an area of severe land degradation

Short Communications Sand moisture as a factor determining depth ...

African Journals Online (AJOL)

1993-11-05

Nov 5, 1993 ... The depths to which the animals burrow are, at least partly. determined by the moisture gradient in the sand. They are, however, incapable of burrowing into totally dry sand. Animals alter their position in the sand in response to changes in moisture content so as to ensure exposure to suitable conditions.

Experimental assessment of the liquefaction resistance of calcareous biogenous sands

Directory of Open Access Journals (Sweden)

Sandoval Eimar

2012-10-01

Full Text Available

ABSTRACT

Liquefaction is a phenomenon in which soils, typically sands, suddenly loose a substantial amount of their shear strength and stiffness, this often triggered by large-magnitude earthquakes. Most liquefaction research has focused on silicate-based sands and not on other sand types, such as calcareous biogenous sands Calcareous sands are usually composed of skeletal or non-skeletal remains of marine organisms, with unique characteristics in terms of their mineralogy surface roughness, particle shape, crushability, and intraparticle porosity. The unique characteristics of calcareous sands suggest that their geotechnical engineering behaviour can be substantially different compared to that of terrigenous sands, including their behaviour under seismic loading, which have not been very well studied

This paper presents the results of an experimental programme aimed at studying the cyclic liquefaction resistance of uncemented calcareous biogenous sands retrieved from south-western Puerto Rico Evaluation of liquefaction potential involved a comprehensive set of isotropically consolidated undrained cyclic triaxial tests on reconstituted samples of this calcareous sand. The programme also included tests on Ottawa terrigenous silica sand samples prepared and tested in similar conditions for comparison purposes.

In general, the experimental results showed that Cabo Rojo calcareous sands had higher liquefaction resistance compared to Ottawa silica sands tested under similar conditions. Important differences between calcareous and silica sands regarding pore pressure generation characteristics and axial strain accumulation were also observed

Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry

Directory of Open Access Journals (Sweden)

Tariq eSiddique

2014-03-01

Full Text Available Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae and Desulfobulbaceae and Archaea (Methanolinea/Methanoregula and Methanosaeta transformed FeIII minerals in MFT to amorphous FeII minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O and goethite (α-FeOOH were the dominant FeIII minerals in MFT. The formation of amorphous iron sulfide (FeS and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy. These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

Microbially-accelerated consolidation of oil sands tailings. Pathway II: solid phase biogeochemistry.

Science.gov (United States)

Siddique, Tariq; Kuznetsov, Petr; Kuznetsova, Alsu; Li, Carmen; Young, Rozlyn; Arocena, Joselito M; Foght, Julia M

2014-01-01

Consolidation of clay particles in aqueous tailings suspensions is a major obstacle to effective management of oil sands tailings ponds in northern Alberta, Canada. We have observed that microorganisms indigenous to the tailings ponds accelerate consolidation of mature fine tailings (MFT) during active metabolism by using two biogeochemical pathways. In Pathway I, microbes alter porewater chemistry to indirectly increase consolidation of MFT. Here, we describe Pathway II comprising significant, direct and complementary biogeochemical reactions with MFT mineral surfaces. An anaerobic microbial community comprising Bacteria (predominantly Clostridiales, Synergistaceae, and Desulfobulbaceae) and Archaea (Methanolinea/Methanoregula and Methanosaeta) transformed Fe(III) minerals in MFT to amorphous Fe(II) minerals during methanogenic metabolism of an added organic substrate. Synchrotron analyses suggested that ferrihydrite (5Fe2O3. 9H2O) and goethite (α-FeOOH) were the dominant Fe(III) minerals in MFT. The formation of amorphous iron sulfide (FeS) and possibly green rust entrapped and masked electronegative clay surfaces in amended MFT. Both Pathways I and II reduced the surface charge potential (repulsive forces) of the clay particles in MFT, which aided aggregation of clays and formation of networks of pores, as visualized using cryo-scanning electron microscopy (SEM). These reactions facilitated the egress of porewater from MFT and increased consolidation of tailings solids. These results have large-scale implications for management and reclamation of oil sands tailings ponds, a burgeoning environmental issue for the public and government regulators.

Formation of aeolian dunes on Anholt, Denmark since AD 1560

DEFF Research Database (Denmark)

Clemmensen, Lars B; Bjørnsen, Mette; Murray, Andrew

2007-01-01

Sand dunes on the island of Anholt (Denmark) in the middle of Kattegat form a relatively barren, temperate climate Aeolian system, locally termed the "Desert". The dunes have developed on top of a raised beach ridge system under the influence of dominant winds from westerly directions. They are r......Sand dunes on the island of Anholt (Denmark) in the middle of Kattegat form a relatively barren, temperate climate Aeolian system, locally termed the "Desert". The dunes have developed on top of a raised beach ridge system under the influence of dominant winds from westerly directions....... They are relatively coarse-grained with an average mean grain size of 480 µm. The last phase of aeolian activity and dune formation on Anholt started after AD 1560, when the local pine forest was removed. Historical sources report intense sand mobilization in the 17th century, and new optically stimulated...... in the beginning of the 20th century probably records a temporary decrease in storminess. Ground-penetrating radar mapping of the internal structures in two dunes in the western part of the Desert (a parabolic dune and a linear dune) indicates the importance of north-westerly (storm) winds during dune formation...

SPECIFIC RESISTANCE AND SPECIFIC INTENSITY OF BELT SANDING OF WOOD

Directory of Open Access Journals (Sweden)

Boleslaw Porankiewicz

2010-06-01

Full Text Available This paper examines and discusses the specific belt sanding resistance K (N·cm-2 and specific belt sanding intensity SI (g·cm-2·min-1, for wood of Pinus sylvestris L., Picea abies L., Quercus robra L., Acer pseudoplatanus L., Alnus glutinosa Gaertn., and Populus Nigra L., by different sanding pressure pS, different sanding grit NG number, and different wood grain angles Phi(v.

Sand (CSW4)

CSIR Research Space (South Africa)

Estuarine and Coastal Research Unit

1982-12-01

Full Text Available This report is one of a series on Cape Estuaries being published under the general title "The Estuaries of the Cape, Part 2". The report provides information on sand estuary: historical background, abiotic and biotic characteristics. It is pointed...

Evaluating the Fraser Health Balanced Scorecard--a formative evaluation.

Science.gov (United States)

Barnardo, Catherine; Jivanni, Amin

2009-01-01

Fraser Health (FH), a large, Canadian, integrated health care network, adopted the Balanced Scorecard (BSC) approach to monitor organizational performance in 2006. This paper reports on the results of a formative evaluation, conducted in April, 2008, to assess the usefulness of the BSC as a performance-reporting system and a performance management tool. Results indicated that the BSC has proven to be useful for reporting performance but is not currently used for performance management in a substantial way.

Class I cultural resource overview for oil shale and tar sands areas in Colorado, Utah and Wyoming.

Energy Technology Data Exchange (ETDEWEB)

O' Rourke, D.; Kullen, D.; Gierek, L.; Wescott, K.; Greby, M.; Anast, G.; Nesta, M.; Walston, L.; Tate, R.; Azzarello, A.; Vinikour, B.; Van Lonkhuyzen, B.; Quinn, J.; Yuen, R.; Environmental Science Division

2007-11-01

In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the 'Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005', Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. The Bureau of Land Management (BLM) is developing a Programmatic Environmental Impact Statement (PEIS) to evaluate alternatives for establishing commercial oil shale and tar sands leasing programs in Colorado, Wyoming, and Utah. This PEIS evaluates the potential impacts of alternatives identifying BLM-administered lands as available for application for commercial leasing of oil shale resources within the three states and of tar sands resources within Utah. The scope of the analysis of the PEIS also includes an assessment of the potential effects of future commercial leasing. This Class I cultural resources study is in support of the Draft Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and Programmatic Environmental Impact Statement and is an attempt to synthesize archaeological data covering the most geologically prospective lands for oil shale and tar sands in Colorado, Utah, and Wyoming. This report is based solely on geographic information system (GIS) data held by the Colorado, Utah, and Wyoming State Historic Preservation Offices (SHPOs). The GIS data include the information that the BLM has provided to the SHPOs. The primary purpose of the Class I cultural resources overview is to provide information on the affected environment for the PEIS. Furthermore, this report provides recommendations to support planning decisions and the management of cultural resources that could be impacted by future

The extraction of bitumen from western oil sands

International Nuclear Information System (INIS)

Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

1992-08-01

The University of Utah tar sand research and development program is concerned with research and development on Utah is extensive oil sands deposits. The program has been intended to develop a scientific and technological base required for eventual commercial recovery of the heavy oils from oil sands and processing these oils to produce synthetic crude oil and other products such as asphalt. The overall program is based on mining the oil sand, processing the mined sand to recover the heavy oils and upgrading them to products. Multiple deposits are being investigated since it is believed that a large scale (approximately 20,000 bbl/day) plant would require the use of resources from more than one deposit. The tasks or projects in the program are organized according to the following classification: Recovery technologies which includes thermal recovery methods, water extraction methods, and solvent extraction methods; upgrading and processing technologies which covers hydrotreating, hydrocracking, and hydropyrolysis; solvent extraction; production of specialty products; and environmental aspects of the production and processing technologies. These tasks are covered in this report

Direct Production of Silicones From Sand

Energy Technology Data Exchange (ETDEWEB)

Larry N. Lewis; F.J. Schattenmann: J.P. Lemmon

2001-09-30

Silicon, in the form of silica and silicates, is the second most abundant element in the earth's crust. However the synthesis of silicones (scheme 1) and almost all organosilicon chemistry is only accessible through elemental silicon. Silicon dioxide (sand or quartz) is converted to chemical-grade elemental silicon in an energy intensive reduction process, a result of the exceptional thermodynamic stability of silica. Then, the silicon is reacted with methyl chloride to give a mixture of methylchlorosilanes catalyzed by cooper containing a variety of tract metals such as tin, zinc etc. The so-called direct process was first discovered at GE in 1940. The methylchlorosilanes are distilled to purify and separate the major reaction components, the most important of which is dimethyldichlorosilane. Polymerization of dimethyldichlorosilane by controlled hydrolysis results in the formation of silicone polymers. Worldwide, the silicones industry produces about 1.3 billion pounds of the basic silicon polymer, polydimethylsiloxane.

Comparing particle-size distributions in modern and ancient sand-bed rivers

Science.gov (United States)

Hajek, E. A.; Lynds, R. M.; Huzurbazar, S. V.

2011-12-01

Particle-size distributions yield valuable insight into processes controlling sediment supply, transport, and deposition in sedimentary systems. This is especially true in ancient deposits, where effects of changing boundary conditions and autogenic processes may be detected from deposited sediment. In order to improve interpretations in ancient deposits and constrain uncertainty associated with new methods for paleomorphodynamic reconstructions in ancient fluvial systems, we compare particle-size distributions in three active sand-bed rivers in central Nebraska (USA) to grain-size distributions from ancient sandy fluvial deposits. Within the modern rivers studied, particle-size distributions of active-layer, suspended-load, and slackwater deposits show consistent relationships despite some morphological and sediment-supply differences between the rivers. In particular, there is substantial and consistent overlap between bed-material and suspended-load distributions, and the coarsest material found in slackwater deposits is comparable to the coarse fraction of suspended-sediment samples. Proxy bed-load and slackwater-deposit samples from the Kayenta Formation (Lower Jurassic, Utah/Colorado, USA) show overlap similar to that seen in the modern rivers, suggesting that these deposits may be sampled for paleomorphodynamic reconstructions, including paleoslope estimation. We also compare grain-size distributions of channel, floodplain, and proximal-overbank deposits in the Willwood (Paleocene/Eocene, Bighorn Basin, Wyoming, USA), Wasatch (Paleocene/Eocene, Piceance Creek Basin, Colorado, USA), and Ferris (Cretaceous/Paleocene, Hanna Basin, Wyoming, USA) formations. Grain-size characteristics in these deposits reflect how suspended- and bed-load sediment is distributed across the floodplain during channel avulsion events. In order to constrain uncertainty inherent in such estimates, we evaluate uncertainty associated with sample collection, preparation, analytical

Difference in the wind speeds required for initiation versus continuation of sand transport on mars: implications for dunes and dust storms.

Science.gov (United States)

Kok, Jasper F

2010-02-19

Much of the surface of Mars is covered by dunes, ripples, and other features formed by the blowing of sand by wind, known as saltation. In addition, saltation loads the atmosphere with dust aerosols, which dominate the Martian climate. We show here that saltation can be maintained on Mars by wind speeds an order of magnitude less than required to initiate it. We further show that this hysteresis effect causes saltation to occur for much lower wind speeds than previously thought. These findings have important implications for the formation of dust storms, sand dunes, and ripples on Mars.

Sand characterization by combined centrifuge and laboratory tests

OpenAIRE

GAUDIN, C; SCHNAID, F; GARNIER, J

2005-01-01

The purpose of this paper is to evaluate new methods of interpretation of in situ tests in sand from correlations established from centrifuge and laboratory data. Emphasis is given to methods that are based on the combination of measurements from independent tests, such as the ratio of the elastic stiffness to ultimate strenght and the ratio of cone resistance and limit pressure. For that purpose, a series of centrifuge tests using a cone penetrometer and a cone pressuremeter was carried out ...

Seasonal fluctuations of phlebotomines sand fly populations ...

African Journals Online (AJOL)

An entomological survey of phlebotomine sand flies was conducted in the Moulay Yacoub province, central Morocco. An anthropic niche (Ouled Aid) and a wild niche (Zliligh) were selected. Sand flies were collected twice a month between April 2011 and March 2012, using sticky traps and CDC light traps. 3675 specimens ...

Molecular Diversity between Salivary Proteins from New World and Old World Sand Flies with Emphasis on Bichromomyia olmeca, the Sand Fly Vector of Leishmania mexicana in Mesoamerica.

Science.gov (United States)

Abdeladhim, Maha; V Coutinho-Abreu, Iliano; Townsend, Shannon; Pasos-Pinto, Silvia; Sanchez, Laura; Rasouli, Manoochehr; B Guimaraes-Costa, Anderson; Aslan, Hamide; Francischetti, Ivo M B; Oliveira, Fabiano; Becker, Ingeborg; Kamhawi, Shaden; Ribeiro, Jose M C; Jochim, Ryan C; Valenzuela, Jesus G

2016-07-01

Sand fly saliva has been shown to have proteins with potent biological activities, salivary proteins that can be used as biomarkers of vector exposure, and salivary proteins that are candidate vaccines against different forms of leishmaniasis. Sand fly salivary gland transcriptomic approach has contributed significantly to the identification and characterization of many of these salivary proteins from important Leishmania vectors; however, sand fly vectors in some regions of the world are still neglected, as Bichromomyia olmeca (formerly known as Lutzomyia olmeca olmeca), a proven vector of Leishmania mexicana in Mexico and Central America. Despite the importance of this vector in transmitting Leishmania parasite in Mesoamerica there is no information on the repertoire of B. olmeca salivary proteins and their relationship to salivary proteins from other sand fly species. A cDNA library of the salivary glands of wild-caught B. olmeca was constructed, sequenced, and analyzed. We identified transcripts encoding for novel salivary proteins from this sand fly species and performed a comparative analysis between B. olmeca salivary proteins and those from other sand fly species. With this new information we present an updated catalog of the salivary proteins specific to New World sand flies and salivary proteins common to all sand fly species. We also report in this work the anti-Factor Xa activity of Lofaxin, a salivary anticoagulant protein present in this sand fly species. This study provides information on the first transcriptome of a sand fly from Mesoamerica and adds information to the limited repertoire of salivary transcriptomes from the Americas. This comparative analysis also shows a fast degree of evolution in salivary proteins from New World sand flies as compared with Old World sand flies.

A Primer on Alberta’s Oil sands Royalties

Directory of Open Access Journals (Sweden)

Sarah Dobson

2015-12-01

Full Text Available Fulfilling its campaign promise, the new NDP government announced a review of Alberta’s royalty framework in June 2015. The province receives royalty revenue from three main sources – natural gas, crude oil, and oil sands. Since the 2009-10 fiscal year the largest contributor to Alberta’s royalty revenues has been the oil sands. If you want a sense of how important oil sands royalties have been for Alberta’s finances, consider this: In the 2014–15 fiscal year, the government collected just over $5 billion from oil sands royalties. These royalties covered over 10 per cent of the province’s operational expenses of $48.6 billion in the same fiscal year. Over the last six fiscal years the oil sands have contributed an average of 10 per cent of revenues to provincial coffers. This makes oil sands royalties the fourth largest contributor behind personal income taxes (23 per cent, federal transfers (13 per cent and corporate income taxes (11 per cent. But how many Albertans really understand how the royalty system works? What do we mean when we say “royalty”? How does the Alberta Government calculate royalties on oil sands producers? If the system is going to change, it’s important that Albertans understand how the current system works. That is what this paper is designed to do. For Albertans to properly judge the impact of new policy, they need a solid understanding of the current policy environment. We all know that oil prices have dropped and oil sands producers are losing profitability. As such, changes to the royalty system could have a deep and profound impact on the sector. Here are some of the issues this primer will study: • Pre-payout projects vs. post-payout projects, in other words, the classification of projects for royalty purposes based on whether the cumulative costs of a project exceed its cumulative revenues • Monthly payment of royalties vs. annual payment • Understanding the unit price of bitumen and how that

Sand ramps as palaeoenvironmental archives: Integrating general principles and regional contexts through reanalysis of the Klipkraal Sands, South Africa

Science.gov (United States)

Rowell, Alexandra L. K.; Thomas, David S. G.; Bailey, Richard M.; Holmes, Peter J.

2018-06-01

Sand ramps occur on a continuum of topographically-controlled landforms, ranging from purely aeolian features (climbing/falling dunes) to talus cones and alluvial fans. Sand ramps have been identified as potentially important palaeoenvironmental archives in dryland regions that possess relatively few Quaternary proxy records. Their utility however requires not only good age control of depositional phases but clear identification of process regimes, determined through morphological and sedimentological analyses, with several recent studies indicating the complexities of palaeoenvironmental interpretations and the controls of ramp development (Bateman et al., 2012; Rowell et al., 2018). Klipkraal Sands is a sand ramp on the north-eastern margin of the semi-arid Karoo that has been important for inferences of the extent of southern African Late Quaternary aeolian activity (Thomas et al., 2002). We reanalyse this feature, in the light of both its significance and other recent studies that have inferred extensive southern African LGM aeolian activity (Telfer et al., 2012, 2014). New sedimentological data and twelve OSL dates indicate the Klipkraal Sands formed episodically between 100-0.14 ka, rather than accumulating rapidly, while sedimentological data question the aeolian affinities of the bulk of the feature. Therefore, Klipkraal is reinterpreted as showing no particular affinity to the LGM, with sediments locally sourced with a significant colluvial component. Only the upper historical sediments can be clearly interpreted as aeolian deposits. A complex interplay of processes is suggested, for which a meaningful palaeoenvironmental interpretation cannot be easily defined. This implies that the local geomorphic processes and controls operating on sand ramps need to be established before they can be fully utilised as palaeoenvironmental archives, with implications for their interpretation worldwide.

Heavy mineral concentration from oil sand tailings

Energy Technology Data Exchange (ETDEWEB)

Chachula, F.; Erasmus, N. [Titanium Corp. Inc., Regina, SK (Canada)

2008-07-01

This presentation described a unique technique to recover heavy minerals contained in the froth treatment tailings produced by oil sand mining extraction operations in Fort McMurray, Alberta. In an effort to process waste material into valuable products, Titanium Corporation is developing technology to recover heavy minerals, primarily zircon, and a portion of bitumen contained in the final stage of bitumen processing. The process technology is being developed to apply to all mined oil sands operations in the Fort McMurray region. In 2004, Titanium Corporation commissioned a pilot research facility at the Saskatchewan Research Council to test dry oil sands tailings. In 2005, a bulk sampling pilot plant was connected to the fresh oil sands tailings pipeline on-site in Fort McMurray, where washed sands containing heavy minerals were processed at a pilot facility. The mineral content in both deposited tailings and fresh pipeline tailings was assessed. Analysis of fresh tailings on a daily basis identified a constant proportion of zircon and higher levels of associated bitumen compared with the material in the deposited tailings. The process flow sheet design was then modified to remove bitumen from the heavy minerals and concentrate the minerals. A newly modified flotation process was shown to be a viable processing route to recover the heavy minerals from froth treatment tailings. 8 refs., 9 tabs., 12 figs.

Creating a soil-like profile for plant growth using tailings sand and fine tails

International Nuclear Information System (INIS)

Li, X.; Fung, M. P. Y.

1996-01-01

Development of a technology to create stable aggregates with a soil-like profile capable of supporting a stable plant community, was discussed as the major challenge and primary task in restoring oil sands processing wastes, and in re-creating a self-sustaining ecosystem. A procedure for creating a soil-like profile using oil sands mining wastes, was described. Clay and water content were critical factors in the aggregation procedure. A study to evaluate the physical, chemical and biological properties of these soils and their suitability as a plant growth medium is currently underway. 6 refs., 3 figs

Western Gas Sands Project. Status report, April 1--April 30, 1979