WorldWideScience

Sample records for west tar sands

  1. Laboratory evaluation of selected tar sand asphalts

    Energy Technology Data Exchange (ETDEWEB)

    Button, J.W.; Epps, J.A.; Gallaway, B.M.

    1980-12-01

    Three tar sand asphalts of similar grades prepared from one syncrude by three different refining methods were characterized by tests commonly used to specify paving asphalts together with certain special tests. Asphalt-aggregate mixtures were prepared using these asphalts and tested in the laboratory to determine strength stiffness stability, tensile properties, temperature effects and water susceptibility. Comparison of the tar sand asphalt properties to conventional petroleum asphalt properties reveal no striking differences.

  2. Solvent extraction of Southern US tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  3. Heating tar sands formations while controlling pressure

    Science.gov (United States)

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  4. The extraction of bitumen from western tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  5. The extraction of bitumen from western tar sands. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  6. Water availability for development of major tar sands areas in Utah

    Energy Technology Data Exchange (ETDEWEB)

    Keefer, T.N.; McQuivey, R.S.

    1979-05-01

    The Sutron Corporation, under contract with Colorado State University, has conducted a study for the Laramie Energy Technology Center (LETC) to determine the availability of water for future extraction of viscous petroleum (bitumen) from the six major tar sands deposits in Utah. Specifically, the areas are: Asphalt Ridge and Whiterocks, which lie immediately west of Vernal, Utah; P.R. Spring, a large area extending from the Colorado River to the White River along Utah's eastern border; Hill Creek, adjacent to P.R. Spring to the west; Sunnyside, immediately across the Green River from Hill Creek between the Price and Green Rivers; and Tar Sand Triangle, near the confluence of the Colorado and Dirty Devil Rivers. The study, conducted between September and December of 1978, was a fact-finding effort involving the compilation of information from publications of the US Geological Survey (USGS), Utah State Engineer, Utah Department of Natural Resources, and other federal and state agencies. The information covers the general physiographic and geologic features of the total area, the estimated water requirements for tar sands development, the availability of water in each of the six areas, and the legal and sociological restraints and impacts. The conclusions regarding water availability for tar sands development in each of the six areas and specific recommendations related to the development of each area are presented also.

  7. Analysis of the environmental control technology for tar sand development

    Energy Technology Data Exchange (ETDEWEB)

    de Nevers, N.; Glenne, B.; Bryner, C.

    1979-06-01

    The environmental technology for control of air pollution, water pollution, and for the disposal, stabilization, and vegetation of the waste tar sand were thoroughly investigated. Although some difficulties may be encountered in any of these undertakings, it seems clear that the air and water pollution problems can be solved to meet any applicable standard. Currently there are two large-scale plants producing liquid fuels from tar sands in Alberta, Canada which use similar technology involving surface mining, hot water extraction, and surface disposal of waste sand. These projects all meet the Canadian environmental control regulations in force at the time they began. The largest US deposits of tar sands are much smaller than the Canadian; 95 percent are located in the state of Utah. Their economics do not appear as attractive as the Canadian deposits. The environmental control costs are not large enough to make an otherwise economic project uneconomic. The most serious environmental conflict likely to occur over the recovery of liquid fuels from the US deposits of tar sands is that caused by the proximity of the deposits to national parks, national monuments, and a national recreation area in Utah. These areas have very stringent air pollution requirements; and even if the air pollution control requirements can be met, there may still be adequate opposition to large-scale mining ventures in these areas to prevent their commercial exploitation. Another environmental constraint may be water rights availability.Essentially all of the water running in the Colorado river basin is now legally allocated. Barring new interpretations of the legality of water rights purchase, Utah tar sands developments should be able to obtain water by purchasing existing irrigation water rights.

  8. 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

    for the White Rim oil. The most attractive potential sources for White Rim oil include beds within one or more of the following formations: the Proterozoic Chuar Group, which is present in the subsurface southwest of the Tar Sand triangle; the Mississippian Delle Phosphatic Member of the Deseret Limestone and equivalent formations, the Permian Kaibab Limestone, the Sinbad Limestone Member of the Triassic Moenkopi Formation, and the Jurassic Arapien Shale, Twin Creek Limestone, and Carmel Formation, which are present west of the Tar Sand triangle; the Pennsylvanian Paradox Formation in the Paradox basin east of the Tar Sand triangle; and the Permian Park City Formation northwest of the Tar Sand triangle. Each formation has a high total organic carbon content and is distributed over a wide enough geographic area to have provided a huge volume of oil. Source beds in all of the formations reached thermal maturity at times prior to or during the time that migration into the White Rim is interpreted to have occurred. Based on all available data, the most likely source for the Tar Sand triangle appears to be the Mississippian Delle Phosphatic Member of the Deseret Limestone. Secondary migration out of the Delle is interpreted to have occurred during the Cretaceous, during Sevier thrusting. Subsequent tertiary migration into the Tar Sand triangle reservoir is interpreted to have occurred later, during middle Tertiary Laramide deformation.

  9. The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1992-04-01

    Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.

  10. Production from multiple zones of a tar sands formation

    Energy Technology Data Exchange (ETDEWEB)

    Karanikas, John Michael; Vinegar, Harold J

    2013-02-26

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.

  11. Trace metals in heavy crude oils and tar sand bitumens

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.G.

    1990-11-28

    Fe, Ni, and V are considered trace impurities in heavy crude oils and tar sand bitumens. In order to understand the importance of these metals, we have examined several properties: (1) bulk metals levels, (2) distribution in separated fractions, (3) size behavior in feeds and during processing, (4) speciation as a function of size, and (5) correlations with rheological properties. Some of the results of these studies show: (1) V and Ni have roughly bimodal size distributions, (2) groupings were seen based on location, size distribution, and Ni/V ratio of the sample, (3) Fe profiles are distinctively different, having a unimodal distribution with a maximum at relatively large molecular size, (4) Fe concentrations in the tar sand bitumens suggest possible fines solubilization in some cases, (5) SARA separated fractions show possible correlations of metals with asphaltene properties suggesting secondary and tertiary structure interactions, and (6) ICP-MS examination for soluble ultra-trace metal impurities show the possibility of unexpected elements such as U, Th, Mo, and others at concentrations in the ppB to ppM range. 39 refs., 13 figs., 5 tabs.

  12. 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.

  13. Tar sands : dirty oil and the future of a continent

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforuk, A.

    2008-07-01

    This book exposes the environmental, social and political costs of oil sands development in Alberta's Athabasca Deposit. It argues that the earth-destroying production methods of bitumen cost nearly 20 times more than conventional crude to produce and upgrade. Most of the tar sands lie in such deep formations that bitumen must be steamed out of the ground using an array of pumps, pipes and horizontal wells. Steam assisted gravity drainage (SAGD), which is the most popular in situ technology used to recover oil sands can have detrimental effects on the boreal forests, wildlife and their habitat. The book emphasized the high greenhouse gas emissions, high energy consumption and suspected health problems associated with oil sands development. It also highlighted the industry's poor record on reclamation. Although some industry players have taken measures to reduce water consumption, more will have to be done to treat and reuse water. The author advocates that changes must be made in order to ensure sustainable development. refs., figs.

  14. Canada's toxic tar sands : the most destructive project on earth

    Energy Technology Data Exchange (ETDEWEB)

    Hatch, C.; Price, M. [Environmental Defence, Toronto, ON (Canada)

    2008-02-15

    This document addressed the environmental problems associated with tar sands development in Alberta, with particular reference to toxicity problems associated with global warming and the impending destruction of the boreal forest. The authors cautioned that the tar sand projects are highly destructive, leaving downstream toxics equivalent to that of a massive slow motion oil spill that has the potential to poison people. Negligent oversights by the government regarding the impact of tar sands development were also discussed, with reference to toxics on site; toxics downwind; and toxics down the pipe. The report also provided information on the future of tar sands development and global warming in Canada. It included a discussion of reverse alchemy; Canada's failed climate politics; a tar sands tax; and taking responsibility. Last, the report addressed toxic enforcement, including the Fisheries Act; Canadian Environmental Protection Act; Canadian Environmental Assessment Act; and Alberta law. It was concluded that while it is a stretch to believe the tar sands can truly be sustainable, there is a great deal that can be done to clean it up. The authors recommended that new tar sands approvals should wait until certain reform elements are implemented, such as passing a real carbon cap; using dry tailings; requiring wildlife offsets; cleaning up refineries and upgraders; ensuring Aboriginal control and benefit; and having regulation and independent monitoring. 104 refs., 6 figs.

  15. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Tar Sand Deposits

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Tar sands represent a significant source of hydrocarbons in the United States. Also known by several other names including bitumen-bearing rocks, natural asphalt,...

  16. SEDIMENTOLOGICAL CHARACTERISTICS OF THE NIGERIAN TAR SAND DEPOSITS IN PARTS OF SOUTHWESTERN NIGERIA

    OpenAIRE

    A Akinmosin; O.O. Osinowo

    2008-01-01

    Particle size distribution of some Afowo tar sands as well as mineralogical and bitumen saturation analyses were carried out with the aim of elucidating the sedimentological properties of the deposits. Fifty samples of tar sands of the Afowo Formation in parts of south western Nigeria were subjected to granulometric and petrological analyses to determine the particle size distribution as well as other textural characteristics. Three of the samples were analyzed for phase identification using ...

  17. On the Periphery of the Tar Sands. Documents in the Classroom.

    Science.gov (United States)

    Hodysh, Henry W.

    2000-01-01

    Explores the diary of Karl Clark that focuses on his experiences in the Athabasca tar sands. The diary helps decipher the nature of 1920s town life and the pioneering spirit involved in exploring the oil sands. Includes background information on Clark. (CMK)

  18. In situ heat treatment of a tar sands formation after drive process treatment

    Science.gov (United States)

    Vinegar, Harold J.; Stanecki, John

    2010-09-21

    A method for treating a tar sands formation includes providing a drive fluid to a hydrocarbon containing layer of the tar sands formation to mobilize at least some hydrocarbons in the layer. At least some first hydrocarbons from the layer are produced. Heat is provided to the layer from one or more heaters located in the formation. At least some second hydrocarbons are produced from the layer of the formation. The second hydrocarbons include at least some hydrocarbons that are upgraded compared to the first hydrocarbons produced by using the drive fluid.

  19. Paleontological overview of oil shale and tar sands areas in Colorado, Utah, and Wyoming.

    Energy Technology Data Exchange (ETDEWEB)

    Murphey, P. C.; Daitch, D.; Environmental Science Division

    2009-02-11

    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. In addition, Congress declared that both research- and commercial-scale development of oil shale and tar sands should (1) be conducted in an environmentally sound manner using management practices that will minimize potential impacts, (2) occur with an emphasis on sustainability, and (3) benefit the United States while taking into account concerns of the affected states and communities. To support this declaration of policy, Congress directed the Secretary of the Interior to undertake a series of steps, several of which are directly related to the development of a commercial leasing program for oil shale and tar sands. One of these steps was the completion of a programmatic environmental impact statement (PEIS) to analyze the impacts of a commercial leasing program for oil shale and tar sands resources on public lands, with an emphasis on the most geologically prospective lands in Colorado, Utah, and Wyoming. For oil shale, the scope of the PEIS analysis includes public lands within the Green River, Washakie, Uinta, and Piceance Creek Basins. For tar sands, the scope includes Special Tar Sand Areas (STSAs) located in Utah. This paleontological resources overview report was prepared in support of the Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and PEIS, and it is intended to be used by Bureau of Land Management (BLM) regional paleontologists and field office staff to support future

  20. Tar sands showdown : Canada and the new politics of oil in an age of climate change

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, T. [Polaris Institute, Ottawa, ON (Canada)

    2009-07-01

    This book outlined the social and environmental issues facing the oil sands industry in Canada, including economic sovereignty, energy security, water rights and free trade. The tar sands have become vital to the Canadian economy, as they have the potential to increase Canada's foreign oil output by 4 to 5 times in the next 15 years. The author discussed the ecological and social impact of the Alberta tar sands and the real cost of development to Albertans and Canadians. Tar sands oil production generates more than 3 times the amount of greenhouse gas emissions than conventional oil production. The industry is also becoming a prime example of the abuse of water sources. The author emphasized the need to build an alternative energy future in an age of global warming. The main objective of this book was to help stimulate a nation-wide public debate about the tar sands and the critical issues at stake regarding Canada's energy future and an environmental strategy for more sustainable development. refs., tabs., figs.

  1. Unconventional pilot steam drive, tar V sand, Long Beach unit, Wilmington Field, CA

    Energy Technology Data Exchange (ETDEWEB)

    Jung, K.D.

    1984-04-01

    This paper reviews the design, implementation and history of the unconventional pilot steam drive (greater than 2,500 ft measured depth) that has been underway since December 24, 1980 in the Tar reservoir in the Long Beach Unit, Wilmington Field, Los Angeles County, California. This paper describes the project through November 30, 1983. The Tar V reservoir is a series of interbedded sands, siltstones and shales in the Middle Repetto formation of lower Pliocene age. The Tar V reservoir in the Long Beach Unit is approximately 200 acres in areal extent, has a vertical gross thickness of 185 ft and a maximum vertical net oil sand thickness of 90 ft comprised of 8 to 10 separate sand units. Oil in place is estimated at 27 MMbbl of stock tank oil. The study area is 9.2 acres in areal extent with an average net oil sand thickness of 81.7 ft. The pilot steam drive was originally installed as an isolated 5.6 acre inverted 5-spot pattern.

  2. Tar sand extraction by steam stimulation and steam drive: measurement of physical properties

    Energy Technology Data Exchange (ETDEWEB)

    Linberg, W.R.

    1980-09-10

    The measurement of the following thermophysical properties of Utah tar sands is in progress: thermal conductivity, specific heat relative permeability, and viscosity (of the recovered bitumen). During the report period (October 1, 1978 to November 1, 1979), experimental procedures have been developed and a basic data set has been measured. Additionally, standard core analysis has been performed for four drill sites in the Asphalt Ridge, Utah area.

  3. 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

  4. EPR and FTIR Characterization of Paramagnetic Transition Metal Ions in Fossil Fuels: Tar Sands

    Science.gov (United States)

    Shepherd, Robert Anthony

    The techniques of EPR and FTIR spectroscopy have been applied to the bitumen and mineral fractions of a tar sand sample originating from Circle Cliffs, Utah to detect and identify paramagnetic transition metal ions present, indicate whether or not they are organically bound, and determine the identities of the complexes in which they occur. An EPR spectrum of the bitumen reveals the presence of V('4+) at a site of axial symmetry. Fitting the spectrum to the second order perturbation solution of the spin Hamiltonian indicates that the spectrum originates from vanadyl etioporphyrin. An EPR spectrum characteristic of Mn('2+) in a carbonate lattice was observed for the mineral component. A quantitative analysis of the mineral components, conducted using FTIR spectroscopy, shows the tar sand mineral fraction consists of the two clays, kaolinite and illite, quartz, gypsum, and one carbonate, dolomite. A computer simulation of the EPR spectrum positively identifies the Mn('2+) host as polycrystalline dolomite, shows the ions are at two crystallographically distinct sites in the dolomite lattice, and gives the relative population at each site. A second feature observed in the EPR spectrum of the mineral fraction is a broad line at g = 4.2 which is attributed to Fe('3+) in kaolinite. A third and final feature observed in the EPR spectrum of the tar sand mineral fraction is a broad line at g = 2. The temperature-dependent behavior of this line suggests that it is due to Fe('3+) in amorphous iron oxides and wustite, two compounds that commonly coat kaolinite surfaces.

  5. Economic and environmental effects of the FQD on crude oil production from tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Kampman, B.; De Buck, A.; Afman, M. [CE Delft, Delft (Netherlands); Van den Berg, J.; Otten, G.J. [Carbon Matters, Den Haag (Netherlands)

    2013-05-15

    The production of unconventional crudes in Canada and Venezuela and exports of these crudes to the EU are investigated. In addition the potential economic and environmental impact of the proposed EU FQD measures (Fuel Quality Directive) on the production of crudes from tar sands and on new tar sand exploration projects are examined. CE Delft has analysed the impact by using a dedicated cost model. For existing projects, the model determines the effect on the basis of marginal production costs. For planned projects the model used the net present value (NPV) of proposed investments. The impacts were determined for a range of crude oil prices and FQD price effects. Combined, for existing and new projects together, the maximum effect would be at a price level at 60 USD/bbl, with savings of up to 19 Mt CO2/y at an FQD price differential of 3 euro/bbl. This overall effect would be substantial and come on top of the total emission reduction effect of the FQD of 60 Mt CO2/y, which will be achieved mostly by the blending of low-carbon fuels and reduced flaring and venting. As part of the reduction of transport greenhouse gas (GHG) emissions, the revised FQD obliges fuel suppliers to reduce these emissions by 6% by 2020 on a well-to-wheel basis. The EU is currently developing a methodology to differentiate fossil fuels on the basis of feedstock and GHG emissions. In the proposal, diesel produced from tar sands, has been given a default emission value of 108.5 gCO2 eq/MJ, while diesel from conventional crude was set at 89.1 gCO2 eq/MJ. The Commission's proposal is currently undergoing an impact assessment and is expected to be resubmitted to the Council later this year (2013)

  6. In situ heat treatment from multiple layers of a tar sands formation

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX)

    2010-11-30

    A method for treating a tar sands formation is disclosed. The method includes providing a drive fluid to a first hydrocarbon containing layer of the formation to mobilize at least some hydrocarbons in the first layer. At least some of the mobilized hydrocarbons are allowed to flow into a second hydrocarbon containing layer of the formation. Heat is provided to the second layer from one or more heaters located in the second layer. At least some hydrocarbons are produced from the second layer of the formation.

  7. Spectroscopic determination of vanadyl porphyrin content in oils obtained from tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Fazliev, D.F.; Sadykov, A.N.; Safiullina, G.K.

    1988-05-01

    Electronic absorption spectroscopy was used to determine vanadyl porphyrin content in oils derived from several tar sand fields in the USSR by in situ combustion or steam injection. The oils were diluted with carbon tetrachloride and their spectra recorded in the 470-650 nm interval. The optical density of the alpha band at 575 nm was calculated and the porphyrin content determined from this property. Results compared favorably with spectral data on vanadyl porphyrin content in acetone extracts. Lower content limits for reliable measurement were found to be 30-40 mg porphyrins per 100 g of oil. Methylene group content in isoprenoid units of the oils was also determined.

  8. Environmental, health, safety, and socioeconomic concerns associated with oil recovery from US tar-sand deposits: state-of-knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.I.; Anspaugh, L.R.; Ricker, Y.E.

    1982-01-08

    Tar-sand petroleum-extraction procedures undergoing field testing for possible commercial application in the US include both surface (above-ground) and in situ (underground) procedures. The surface tar-sand systems currently being field tested in the US are thermal decomposition processes (retorting), and suspension methods (solvent extraction). Underground bitumen extraction procedures that are also being field tested domestically are in situ combustion and steam-injection. Environmental, health, safety, and socioeconomic concerns associated with construction and operation of 20,000-bbl/d commercial tar-sand surface and in situ facilities have been estimated and are summarized in this report. The principal regulations that commercial tar-sand facilities will need to address are also discussed, and environmental control technologies are summarized and wherever possible, projected costs of emission controls are stated. Finally, the likelihood-of-occurrence of potential environmental, health, and safety problems that have been determined are reviewed, and from this information inference is made as to the environmental acceptability of technologically feasible 20,000-bbl/d commercial tar-sand oil-extraction procedures.

  9. Environmental survey - tar sands in situ processing research program (Vernal, Uintah County, Utah). [Reverse-forward combustion; steam injection

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Q.

    1980-03-01

    Research will be done on the reverse-forward combustion and steam injection for the in-situ recovery of oil from tar sands. This environmental survey will serve as a guideline for the consideration of environmental consequences of such research. It covers the construction phase, operational phase, description of the environment, potential impacts and mitigations, coordination, and alternatives. (DLC)

  10. Moving hydrocarbons through portions of tar sands formations with a fluid

    Science.gov (United States)

    Stegemeier, George Leo; Mudunuri, Ramesh Raju; Vinegar, Harold J.; Karanikas, John Michael; Jaiswal, Namit; Mo, Weijian

    2010-05-18

    A method for treating a tar sands formation is disclosed. The method includes heating a first portion of a hydrocarbon layer in the formation from one or more heaters located in the first portion. The heat is controlled to increase a fluid injectivity of the first portion. A drive fluid and/or an oxidizing fluid is injected and/or created in the first portion to cause at least some hydrocarbons to move from a second portion of the hydrocarbon layer to a third portion of the hydrocarbon layer. The second portion is between the first portion and the third portion. The first, second, and third portions are horizontally displaced from each other. The third portion is heated from one or more heaters located in the third portion. Hydrocarbons are produced from the third portion of the formation. The hydrocarbons include at least some hydrocarbons from the second portion of the formation.

  11. Discussion of the role of asphaltene in heavy crudes and tar sands

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1981-01-01

    A discussion of the role of asphaltene in heavy crudes and tar sands covers a definition of heavy oil as a dark-colored, high-density, and high-viscosity oil, rich in heteroatom components, such as asphaltics (asphaltenes plus resin), and metallo complexes, such as vanadyl porphyrin; the classification of heavy oil into thermally transformed, biodegraded, and severely cracked oil; the structural parameters of various asphaltenes derived from petroleum, shale, and coal; and the relationship of asphaltene content in heavy oil to the metals and sulfur contents, to upgrading via thermal and hydrocracking processes, to reactivity, to mesophase growth, to enhanced oil recovery, and to weathering, which was shown in one study of an oilspill to increase the asphaltenes and carbene content.

  12. Varying properties of in situ heat treatment of a tar sands formation based on assessed viscosities

    Energy Technology Data Exchange (ETDEWEB)

    Karanikas, John Michael; Vinegar, Harold J

    2014-03-04

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. A viscosity of one or more zones of the hydrocarbon layer is assessed. The heating rates in the zones are varied based on the assessed viscosities. The heating rate in a first zone of the formation is greater than the heating rate in a second zone of the formation if the viscosity in the first zone is greater than the viscosity in the second zone. Fluids are produced from the formation through the production wells.

  13. Technology assessment: environmental, health, and safety impacts associated with oil recovery from US tar-sand deposits

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, J.I.; Anspaugh, L.R.; Ricker, Y.E.

    1981-10-13

    The tar-sand resources of the US have the potential to yield as much as 36 billion barrels (bbls) of oil. The tar-sand petroleum-extraction technologies now being considered for commercialization in the United States include both surface (above ground) systems and in situ (underground) procedures. The surface systems currently receiving the most attention include: (1) thermal decomposition processes (retorting); (2) suspension methods (solvent extraction); and (3) washing techniques (water separation). Underground bitumen extraction techniques now being field tested are: (1) in situ combustion; and (2) in situ steam-injection procedures. At this time, any commercial tar-sand facility in the US will have to comply with at least 7 major federal regulations in addition to state regulations; building, electrical, and fire codes; and petroleum-industry construction standards. Pollution-control methods needed by tar-sand technologies to comply with regulatory standards and to protect air, land, and water quality will probably be similar to those already proposed for commercial oil-shale systems. The costs of these systems could range from about $1.20 to $2.45 per barrel of oil produced. Estimates of potential pollution-emisson levels affecting land, air, and water were calculated from available data related to current surface and in situ tar-sand field experiments in the US. These data were then extrapolated to determine pollutant levels expected from conceptual commercial surface and in situ facilities producing 20,000 bbl/d. The likelihood-of-occurrence of these impacts was then assessed. Experience from other industries, including information concerning health and ecosystem damage from air pollutants, measurements of ground-water transport of organic pollutants, and the effectiveness of environmental-control technologies was used to make this assessment.

  14. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States); Vala, David [Murray High School, Murray, UT 84107 (United States); Reese, Barbara K. [Butler Middle School, Cottonwood Heights, UT 84121 (United States); Freedman, Dina R. [Hillside Middle School, Salt Lake City, UT 84108 (United States); Stenten, Christina J. [Draper Park Middle School, Draper, UT 84020 (United States); Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States)

    2015-11-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  15. Coliquefaction of coal, tar sand bitumen and plastic (interaction among coal, bitumen and plastic); Sekitan/tar sand bitumen/plastic no kyoekika ni okeru kyozon busshitsu no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H.; Okuyama, Y.; Matsubara, K. [NKK Corp., Tokyo (Japan); Kamo, T.; Sato, Y. [National Institute for Resources and Environment, Tsukuba (Japan)

    1996-10-28

    For the improvement of economy, coliquefaction of coal, tar sand bitumen and plastic was performed under low hydrogen pressure, to investigate the influence of interaction among these on the liquefaction characteristics. For comparison, coliquefaction was also performed under the hydrogen pressure same as the NEDOL process. In addition, for clarifying its reaction mechanism, coliquefaction of dibenzyl and plastic was performed as a model experiment, to illustrate the distribution of products and composition of oil, and to discuss the interaction between dibenzyl and various plastics, and between various plastics. Under direct coal liquefaction conditions, coprocessing of Tanito Harum coal, Athabasca tar sand and plastic was carried out under low hydrogen pressure with an autoclave. The observed value of oil yield was higher than the calculated value based on the values from separate liquefaction of coal and plastic, which suggested the interaction between coal and the mixed plastic. The results of coliquefaction of coal, tar sand bitumen and plastic could be explained from the obtained oil yield and its composition by the coliquefaction of dibenzyl and plastic. 2 refs., 3 tabs.

  16. Assessment of Research Needs for Oil Recovery from Heavy-Oil Sources and Tar Sands (FERWG-IIIA)

    Energy Technology Data Exchange (ETDEWEB)

    Penner, S.S.

    1982-03-01

    The Fossil Energy Research Working Group (FERWG), at the request of J.W. Mares (Assistant Secretary for Fossil Energy) and A.W. Trivelpiece (Director, Office of Energy Research), has reviewed and evaluated the U.S. programs on oil recovery from heavy oil sources and tar sands. These studies were performed in order to provide an independent assessment of research areas that affect the prospects for oil recovery from these sources. This report summarizes the findings and research recommendations of FERWG.

  17. Preliminary feasibility studies in times of rapid cost escalation. [Oil shale and tar sand industries

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, E.D.; Moll, A.J.

    1976-01-01

    Not the least of the problems delaying the development and commercialization of synthetic fuel processes has been the extraordinary escalation of cost estimates by factors of up to ten in the past eight years. This study identifies and analyzes some of the most important contributing factors that have converged in the last few years. These factors include overoptimism and ill-defined project scope in the early stages, tightening environmental controls, difficulties in obtaining raw materials and fuels, general inflationary trends, ''hyperinflation'' of the costs of critical equipment, local labor shortages, and increased times required for procurement and construction. Cost increases have been particularly dramatic for ''offsites,'' liberally defined as nonprocess related parts of projects. Case histories of oil shale and tar sand developments are analyzed. Learning curves of costs during development and commercial use are studied. The analysis suggests that the worst of the extraordinary increases (above general inflationary trends) are probably over. Criteria to judge the state of development of processes are given, and some procedures to avoid future pitfalls are suggested.

  18. Modelling Safety Factors of Slope Stability for Open-Pit Mining of Nigerian Tar-Sand Deposits

    Directory of Open Access Journals (Sweden)

    D. A. Alao

    2010-06-01

    Full Text Available Slope failure might lead to loss of lives and valuable equipment which would increase overall operational cost of running a mine. The need to have stable slopes in open-pit mining of Nigerian tar sand deposits of Dahomey Basin, Southwestern Nigeria is emphasized in this study. At Loda village, Southwestern Nigeria, samples of the laterite soil and alluvial sand which overlie the tar sand occurrence were subjected to geotechnical tests. Computer simulation of bench face angles was carried out using SLOPE/W Software to determine the bench face angle(s with the least susceptibility to failure. Unit weight (ö, cohesion (c and angle of internal friction (0 values for the laterite soil were 25 kN/m, 45 kPa and 41 respectively for laterite. The corresponding values for the laterite, soil were 18 kN/m3, 0kPa and 34°. These values were used to run the software programme to simulate different bench face angles that could be cut into the two lithologic units. Factors of safety values between 3.58 and 1.73 were obtained for bench face angles between 10° and 30° which are least susceptible to failure even when inundation is considered. This research results have enabled us to recommend the use of bench slope angles ranging from 10° and 30° coupled with adequate drainage conditions which should guaranty optimum output.

  19. Chemical modification of a bitumen and its non-fuel uses. [Reactions of tar sand asphaltenes in synthesis of non-fuel products

    Energy Technology Data Exchange (ETDEWEB)

    Moschopedis, S.E.; Speight, J.G.

    1974-01-01

    Simple reactions are described whereby tar sand bitumen can be converted to a whole range of materials. Examples are given to illustrate the non-fuel uses of the products. The following reactions of Athabasca asphaltenes are considered: oxidation, halogenation, sulfonation and sulfomethylation, phosphorylation, hydrogenation, reactions with S and O, reactions with metal salts, and miscellaneous chemical conversions. (JGB)

  20. An NMR (Nuclear Magnetic Resonance) Investigation of the Chemical Association and Molecular Dynamics in Asphalt Ridge Tar Sand Ore and Bitumen

    Science.gov (United States)

    Netzel, D. A.; Coover, P. T.

    1987-09-01

    Preliminary studies on tar sand bitumen given in this report have shown that the reassociation of tar sand bitumen to its original molecular configuration after thermal stressing is a first-order process requiring nearly a week to establish equilibrium. Studies were also conducted on the dissolution of tar sand bitumen in solvents of varying polarity. At a high-weight fraction of solute to solvent the apparent molecular weight of the bitumen molecules was greater than that of the original bitumen when dissolved in chloroform-d{sub 1} and benzene-d{sub 6}. This increase in the apparent molecular weight may be due to micellar formation or a weak solute-solvent molecular complex. Upon further dilution with any of the solvents studied, the apparent molecular weight of the tar sand bitumen decreased because of reduced van der Waals forces of interaction and/or hydrogen bonding. To define the exact nature of the interactions, it will be necessary to have viscosity measurements of the solutions.

  1. Characterization and utilization of hydrotreated products produced from the Whiterocks (Utah) tar sand bitumen-derived liquid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.H.; Longstaff, D.C.; Deo, M.D.; Hanson, F.V.; Oblad, A.G.

    1991-01-01

    The bitumen-derived liquid produced in a 4-inch diameter fluidized-bed reactor from the mined and crushed ore from the Whiterocks tar sand deposit has been hydrotreated in a fixed-bed reactor. The purpose was to determine the extent of upgrading as a function of process operating variable. A sulfided nickel-molybendum on alumina hydrodenitrogenation catalyst was used in all experiments. Moderately severe operating conditions were employed; that is, high reaction temperature (617--680 K) high reactor pressure (11.0--17.1 MPa) and low liquid feed rate (0.18--0.77 HSV); to achieve the desired reduction in heteroatom content. Detailed chemical structures of the bitumen-derived liquid feedstock and the hydrotreated total liquid products were determined by high resolution gas chromatography - mass spectrometry analyses. The compounds identified in the native bitumen included isoprenoids; bicyclic, tricycle, and tetracyclic terpenoids; steranes; hopanes; and perhydro-{beta}-carotenes. In addition, normal and branched alkanes and alkenes and partially dehydrogenated hydroaromatics were identified in the bitumen-derived liquid. The dominant pyrolysis reactions were: (1) the dealkylation of long alkyl side chains to form {alpha} - and isoolefins; and (2) the cleavage of alkyl chains linking aromatic and hydroaromatic clusters. Olefinic bonds were not observed in the hydrotreated product and monoaromatic hydrocarbons were the predominant aromatic species. The properties of the jet fuel fractions from the hydrotreated products met most of the jet fuel specifications. The cetane indices indicated these fractions would be suitable for use as diesel fuels.

  2. Characterization and utilization of hydrotreated products produced from the Whiterocks (Utah) tar sand bitumen-derived liquid

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, C.H.; Longstaff, D.C.; Deo, M.D.; Hanson, F.V.; Oblad, A.G.

    1991-12-31

    The bitumen-derived liquid produced in a 4-inch diameter fluidized-bed reactor from the mined and crushed ore from the Whiterocks tar sand deposit has been hydrotreated in a fixed-bed reactor. The purpose was to determine the extent of upgrading as a function of process operating variable. A sulfided nickel-molybendum on alumina hydrodenitrogenation catalyst was used in all experiments. Moderately severe operating conditions were employed; that is, high reaction temperature (617--680 K) high reactor pressure (11.0--17.1 MPa) and low liquid feed rate (0.18--0.77 HSV); to achieve the desired reduction in heteroatom content. Detailed chemical structures of the bitumen-derived liquid feedstock and the hydrotreated total liquid products were determined by high resolution gas chromatography - mass spectrometry analyses. The compounds identified in the native bitumen included isoprenoids; bicyclic, tricycle, and tetracyclic terpenoids; steranes; hopanes; and perhydro-{beta}-carotenes. In addition, normal and branched alkanes and alkenes and partially dehydrogenated hydroaromatics were identified in the bitumen-derived liquid. The dominant pyrolysis reactions were: (1) the dealkylation of long alkyl side chains to form {alpha} - and isoolefins; and (2) the cleavage of alkyl chains linking aromatic and hydroaromatic clusters. Olefinic bonds were not observed in the hydrotreated product and monoaromatic hydrocarbons were the predominant aromatic species. The properties of the jet fuel fractions from the hydrotreated products met most of the jet fuel specifications. The cetane indices indicated these fractions would be suitable for use as diesel fuels.

  3. 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

    A sand filter is used to help maintain water clarity at the K West Basin where highly radioactive sludge is stored. Eventually that sand filter will require disposal. The radionuclide content of the solids trapped in the sand filter will affect the selection of the sand filter disposal pathway. The Pacific Northwest National Laboratory (PNNL) was contracted by the K Basin Operations & Plateau Remediation Project (operations contractor CH2M Hill) to analyze the radionuclide content of the solids collected from the backwash of the K West Basin sand filter. The radionuclide composition in the sand filter backwash solids will be used by CH2M Hill to determine if the sand filter media and retained sludge solids will be designated as transuranic waste for disposal purposes or can be processed through less expensive means. On October 19, 2015, K Basin Operations & Plateau Remediation Project staff backwashed the sand filter into the North Load-Out Pit (NLOP) and immediately collected sample slurry from a sampling tube positioned 24 in. above the NLOP floor. The 764 g sand filter backwash slurry sample, KW-105 SFBW-001, was submitted to PNNL for analysis on October 20, 2015. Solids from the slurry sample were consolidated into two samples (i.e., a primary and a duplicate sample) by centrifuging and measured for mass (0.82 g combined – wet centrifuged solids basis) and volume (0.80 mL combined). The solids were a dark brown/orange color, consistent with iron oxide/hydroxide. The solids were dried; the combined dry solids mass was 0.1113 g, corresponding to 0.0146 weight percent (wt%) solids in the original submitted sample slurry. The solids were acid-digested using nitric and hydrochloric acids. Insoluble solids developed upon dilution with 0.5 M HNO3, corresponding to an average 6.5 wt% of the initial dry solids content. The acid digestate and insoluble solids were analyzed separately by gamma spectrometry. Nominally, 7.7% of the 60Co was present

  4. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research. Quarterly technical progress report, October--December 1992

    Energy Technology Data Exchange (ETDEWEB)

    Speight, J.G.

    1992-12-31

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO{sub 2} HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  5. Identifying the source of tar balls deposited along the beaches of Goa in 2013 and comparing with historical data collected along the West Coast of India.

    Science.gov (United States)

    Suneel, V; Vethamony, P; Naik, B G; Krishna, M S; Jadhav, Lakshmikant

    2015-09-15

    Deposition of oil residues, also known as tar balls, is a seasonal phenomenon, and it occurs only in the southwest monsoon season along the west coast of India. This has become a serious environmental issue, as Goa is a global tourist destination. The present work aims at identifying the source oil of the tar balls that consistently depositing along the Goa coast using multi-marker fingerprint technique. In this context, the tar ball samples collected in May 2013 from 9 beaches of Goa coast and crude oils from different oil fields and grounded ship were subject to multi-marker analyses such as n-alkanes, pentacyclic terpanes, regular steranes, compound specific isotope analysis (CSIA) and principle component analysis (PCA). The n-alkane weathering index shows that samples have been weathered to various degrees, and the status of weathering is moderate. Since the international tanker route passes closer to the west coast of India (WCI), it is generally presumed that tanker wash is the source of the tar balls. We found that 2010/2011 tar balls are as tanker wash, but the present study demonstrates that the Bombay High (BH) oil fields can also contribute to oil contamination (tar balls) along ≈ 650 km stretch of the WCI, running from Gujarat in the north to Goa in the south. The simulated trajectories show that all the particles released in April traveled in the southeast direction, and by May, they reached the Goa coast with the influence of circulation of Indian monsoon system. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Appraisal of the Pelican River sand-plain aquifer, west-central Minnesota

    Science.gov (United States)

    Miller, R.T.

    1982-01-01

    The Pelican River sand-plain area includes approximately 200 square miles of outwash deposits in parts of Decker, Otter Tail, and Clay Counties in west-central Minnesota. Saturated thickness of the outwash is as much as 140 feet and yields of properly constructed wells locally may exceed 1,200 gallons per minute.

  7. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 1 -- Base program. Final report, October 1986--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.

    1994-05-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  8. Effect of Carbon and Nitrogen Sources on Polygalacturonase Production by Trichoderma viride (BITRS-1001 Isolated from Tar Sand in Ondo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ogunmolu, F. E.

    2011-01-01

    Full Text Available The effects of the various carbon and nitrogen substrates on the growth and polygalacturonase activity of Trichoderma viride (BITRS-1001 isolated from the tar sand deposit in Gbelejuloda-Irele Ondo State, Nigeria were investigated in submerged cultivation at 30 °C ± 2 °C. The commercial carbon and nitrogen substrates included sucrose, fructose, starch, maltose, lactose and peptone, sodium nitrate, urea and casein respectively. All the carbon substrates used supported the growth of T. viride (0.566 to 0.156 g/50 mL of culture medium with starch supporting the highest biomass yield and sucrose the least biomass yield. Maximum polygalacturonase activity of 3033 U/mL was recorded in maltose medium. Maximum biomass yield on the nitrogen sources was observed in the organic nitrogen namely peptone and casein with values not significantly different from each other at p ≤ 0.05. In the determination of the crude enzyme activity on the nitrogen sources, maximum polygalacturonase activity of 12,400 U/mL was recorded in peptone medium. Hence, a careful manipulation of these nutrient substrates could help to optimise the production of this enzyme on a large scale.

  9. Origin of amphibole-rich beach sands from Tila-Mati, Karwar, central-west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Iyer, S.D.

    The pocket beach at Tila-Mati, Karwar, central west coast of India, is characterised by the occurrence of amphibole-rich (chiefly tremolite-actinolite) coarse sand in the zone of minimal impact of waves and currents. In the total sediment, grain...

  10. Characterization and Ecophysiological Observations on Coastal Sand Dune Vegetation from Goa, Central West Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Rodrigues, R.S.

    Coastal Sand Dune flora (CSD) forms a specialized group of plants commonly referred as psammophytes. Goa has limited natural resources including beaches and sand dunes. The state is globally known for its tourism activities, which pressurize...

  11. Devonian sand injections and volcanism in the Murzuq Basin (south-west Libya)

    DEFF Research Database (Denmark)

    Moreau, Julien; Ghienne, Jean-Francois

    The highly prolific Murzuq basin in SW Libya was considered devoid of large sand injection system and volcanic activity during the Lower Palaeozoic. This study identified numerous evidences of kilometre-scale sand injections in association with volcanism of Lower Devonian age. The sand injection...

  12. Research investigations in oil shale, tar sand, coal research, advanced exploratory process technology, and advanced fuels research: Volume 2 -- Jointly sponsored research program. Final report, October 1986--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Smith, V.E.

    1994-09-01

    Numerous studies have been conducted in five principal areas: oil shale, tar sand, underground coal gasification, advanced process technology, and advanced fuels research. In subsequent years, underground coal gasification was broadened to be coal research, under which several research activities were conducted that related to coal processing. The most significant change occurred in 1989 when the agreement was redefined as a Base Program and a Jointly Sponsored Research Program (JSRP). Investigations were conducted under the Base Program to determine the physical and chemical properties of materials suitable for conversion to liquid and gaseous fuels, to test and evaluate processes and innovative concepts for such conversions, to monitor and determine environmental impacts related to development of commercial-sized operations, and to evaluate methods for mitigation of potential environmental impacts. This report is divided into two volumes: Volume 1 consists of 28 summaries that describe the principal research efforts conducted under the Base Program in five topic areas. Volume 2 describes tasks performed within the JSRP. Research conducted under this agreement has resulted in technology transfer of a variety of energy-related research information. A listing of related publications and presentations is given at the end of each research topic summary. More specific and detailed information is provided in the topical reports referenced in the related publications listings.

  13. Map of percent scleractinian coral cover and sand along camera tow tracks in west Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This map displays optical validation observation locations and percent coverage of scleractinian coral and sand overlaid on bathymetry and landsat imagery northwest...

  14. The extraction of bitumen from western oil sands. Final report, July 1989--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1994-03-01

    Research and development of surface extraction and upgrading processes of western tar sands are described. Research areas included modified hot water, fluidized bed, and rotary kiln pyrolysis of tar sands for extraction of bitumen. Bitumen upgrading included solvent extraction of bitumen, and catalytic hydrotreating of bitumen. Characterization of Utah tar sand deposits is also included.

  15. Coal tar in dermatology

    Energy Technology Data Exchange (ETDEWEB)

    Roelofzen, J.H.J.; Aben, K.K.H.; Van Der Valk, P.G.M.; Van Houtum, J.L.M.; Van De Kerkhof, P.C.M.; Kiemeney, L.A.L.M. [Radboud University Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Dermatology

    2007-07-01

    Coal tar is one of the oldest treatments for psoriasis and eczema. It has anti-inflammatory, antibacterial, antipruritic and antimitotic effects. The short-term side effects are folliculitis, irritation and contact allergy. Coal tar contains carcinogens. The carcinogenicity of coal tar has been shown in animal studies and studies in occupational settings. There is no clear evidence of an increased risk of skin tumors or internal tumors. Until now, most studies have been fairly small and they did not investigate the risk of coal tar alone, but the risk of coal tar combined with other therapies. New, well-designed, epidemiological studies are necessary to assess the risk of skin tumors and other malignancies after dermatological use of coal tar.

  16. Treating tar sands formations with dolomite

    Science.gov (United States)

    Vinegar, Harold J.; Karanikas, John Michael

    2013-10-15

    A method for treating a karsted formation containing heavy hydrocarbons and dolomite includes providing heat to at least part of one or more karsted layers in the formation from one or more heaters located in the karsted layers. A temperature in at least one of the karsted layers is allowed to reach a decomposition temperature of dolomite in the formation. The dolomite is allowed to decompose and at least some hydrocarbons are produced from at least one of the karsted layers of the formation.

  17. Identifying the source of tar balls deposited along the beaches of Goa in 2013 and comparing with historical data collected along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Vethamony, P.; Naik, B.G.; Krishna, M.S.; Jadhav, L.

    MOB-1tb and VEL-2tb, for which the values are very low (0.004, 0.002) signifying that they have weathered severely. The L/H ratio of tar balls is also less compared to the crude oils, suggesting that the samples had weathered significantly (might..., Suneel et. al., 2014).  9      Fig. 2. GC-MS Hopane chromatograms (m/z-191) for the sample of Maj-2, MOB-2, AGO-1 and BEN-1. 1-Ts, 2-Tm, 3-C29α, 4- C29β, 5-OL, 6- C30αβ, 7- C30βα, 8- C31αβ-S, 9- C31βα-S, 10-C31αβ-R, 11- C32αβ-S, 12- C32βα-S, 13-C32αβ...

  18. Primary sand-dune plant community and soil properties during the west-coast India monsoon

    Directory of Open Access Journals (Sweden)

    Willis A.

    2016-06-01

    Full Text Available A seven-station interrupted belt transect was established that followed a previously observed plant zonation pattern across an aggrading primary coastal dune system in the dry tropical region of west-coast India. The dominant weather pattern is monsoon from June to November, followed by hot and dry winter months when rainfall is scarce. Physical and chemical soil characteristics in each of the stations were analysed on five separate occasions, the first before the onset of monsoon, three during and the last post-monsoon. The plant community pattern was confirmed by quadrat survey. A pH gradient decreased with distance from the shoreline. Nutrient concentrations were deficient, increasing only in small amounts until the furthest station inland. At that location, there was a distinct and abrupt pedological transition zone from psammite to humic soils. There was a significant increase over previous stations in mean organic matter, ammonium nitrate and soil-water retention, although the increase in real terms was small. ANOVA showed significant variation in electrical conductivity, phosphorus, calcium, magnesium and sodium concentrations over time. There was no relationship between soil chemistry characteristics and plant community structure over the transect. Ipomoea pes-caprae and Spinifex littoreus were restricted to the foredunes, the leguminous forb Alysicarpus vaginalis and Perotis indica to the two stations furthest from the strand. Ischaemum indicum, a C4 perennial grass species adopting an ephemeral strategy was, in contrast, ubiquitous to all stations.

  19. Provenance Study Of Bituminous Sands In Eastern Dahomey Basin ...

    African Journals Online (AJOL)

    One hundred and twenty (120) tar sand samples were collected at 8 localities along the Nigerian tar sand belt for both quartz variety and heavy mineral analyses. The quartz variety study carried out on 30 samples revealed both polycrystalline and monocrystalline quartz types occurring in all samples but in different ...

  20. Sedimentary Characteristics of Buried Sand Layers Deposited in a Coastal Swamp in West Aceh, Indonesia, in the Early 15th Century

    Science.gov (United States)

    Morgan, T.; Monecke, K.; Meilianda, E.; Pilarczyk, J.; Rusydy, I.; Moena, A.; Muzhaffat, H.; Rais, A.; Yolanda, I. P.

    2016-12-01

    Sediment cores from the coastal region of West Aceh, Indonesia, an area largely affected by the December 2004 Sumatra Andaman earthquake and resulting Indian Ocean tsunami, preserve evidence of two buried sand layers of possible tsunamigenic origin deposited in the early 15th century. The study site is dominated by beach ridge morphology with an alternation of beach ridges and swales characteristic of long-term coastal progradation. We targeted a low-lying area landward of a prominent beach ridge that is thought to have formed in the aftermath of the last predecessor of the 2004 event, and marks the position of the coastline in the late 14th and early 15th century. Using a hand auger and plastic tubes, 80 core samples up to 2.5 m in depth were recovered. Sand samples were analyzed using a laser diffraction particle size analyzer and prepared for microfossil analysis. The swale deposits are mostly composed of peat and overlie shallow marine sands forming the base of the beach ridge plain. Within the uppermost centimeters, a number of cores show a tsunami inundation in 2004. Intercalated within the peat deposits we found two buried sand layers at a depth of 70-100 cm below the surface. The lower sand layer is 1-6 cm thick and could only be traced in a handful of cores; the upper layer is more widespread and consistently thicker, measuring 11-17 cm, with 5-14 cm of peat in between the two sand sheets. The sand layers consist of massive to normally graded fine to medium sand and show sharp upper and lower boundaries indicating abrupt depositional events. Grain size distributions of the 2004 tsunami sand as well as of buried sand layers match shoreface sediment samples retrieved in 10 m water depth, suggesting a predominantly offshore source. Based on initial radiocarbon ages and estimates of sedimentation rates, the two buried sand layers were deposited in the early 15th century and are separated by only a few decades.

  1. Entomological studies of phlebotomine sand flies (Diptera: Psychodidae) in relation to cutaneous leishmaniasis transmission in Al Rabta, North West of Libya.

    Science.gov (United States)

    Dokhan, Mostafa Ramahdan; Kenawy, Mohamed Amin; Doha, Said Abdallah; El-Hosary, Shabaan Said; Shaibi, Taher; Annajar, Badereddin Bashir

    2016-02-01

    Al Rabta in the North-West of Libya is a rural area where cutaneous leishmaniasis (CL) is endemic for long time. Few reports are available on sand flies in this area which is an important focus of CL. Therefore, this study aimed at updating the species composition, and monthly fluctuation of sand flies in this area. Sand flies were biweekly collected by CDC light traps from June to November 2012 and April to November 2013 in two villages, Al Rabta East (RE) and Al Rabta West (RW). Nine species (6 Phlebotomus and 3 Sergentomyia) were reported in the two villages. A total of 5605 and 5446 flies were collected of which Phlebotomus represented 59.30 and 56.63% in RE and RW, respectively. Sergentomyia minuta and Phlebotomus papatasi were the abundant species. Generally, more males were collected than females for all species. The overall ratios (males: females) for most of species were not deviated from the expected 1:1 ratio (Chi-squared, P>0.05). Sand fly abundance (fly/trap) is directly related to the temperature and RH (P0.05). Flies were active from April to November with increased activity from June to October. Prominent peaks were in September and June. The abundance of P. papatasi and Phlebotomus sergenti, vectors of CL (August-October) coincided with the reported higher numbers of CL cases (August- November). The obtained results could be important for the successful planning and implementation of leishmaniasis control programs. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Map of percent scleractinian coral cover and sand along camera tows and ROV tracks of West Maui, Hawaii

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This map displays optical validation observation locations and percent coverage of scleractinian coral and sand overlaid on bathymetry and landsat imagery. Optical...

  3. Permanent deformation behavior of naturally occurring bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2008-01-01

    Full Text Available Oil sand, or tar sand, is a generic name given to bituminous sand deposits that are rich in bitumen or asphalt content to the extent that oil can be extracted from these deposits. The typical 8% to 15% presence of bitumen in the soil composition...

  4. Kilometre-scale sand injectites in the intracratonic Murzuq Basin (South-west Libya): an igneous trigger?

    DEFF Research Database (Denmark)

    Moreau, Julien; Ghienne, Jean-Francois; Hurst, Andrew

    2012-01-01

    Mount Telout, situated at the edge of the Murzuq Basin, is a 325 m high conical hill within a circular collapse structure that records 0.5 km3 of sand intrusion into Silurian shales. Based on a comparison with other similar circular collapse structures around the Murzuq Basin, it is argued that s...

  5. Implementation of an ex situ stabilization technique at the Sand Springs superfund site to solidify and stabilize acid tar sludges involving a quick-lime based stabilization process and innovative equipment design

    Energy Technology Data Exchange (ETDEWEB)

    McManus, R.W. [SOUND Environmental Services, Inc., Dallas, TX (United States); Grajczak, P. [ARCO, Los Angeles, CA (United States); Wilcoxson, J.C. [ARCO, Plano, TX (United States); Webster, S.D. [Environmental Protection Agency, Dallas, TX (United States)

    1997-12-31

    An old refinery site was safely remediated a year before schedule and for 25% less than final engineering estimates for the stabilization remedy thanks to energetic project management and innovative design involving ex situ stabilization/solidification of acid tar sludges. A quicklime based process, Dispersion by Chemical Reaction (DCR{trademark}), was employed to solidify and stabilize (SS) over 103,000 cubic meters (135,000 cubic yards) of petroleum waste, mostly acidic tarry sludge. The SS process was selected over competing methods because it afforded minimal volume increase, could readily achieve Record of Decision (ROD) specified physical and chemical treatment goals, could be implemented with treatment equipment that minimized emissions, and could be performed with low reagent usage and at low cost. To ensure treatment goals were achieved and an accelerated schedule met, a custom designed and fabricated transportable treatment unit (TTU) was employed to implement the process. The treated material was visually soil-like in character, it was left in stockpiles for periods of time, and it was placed and compacted in the on site landfill using standard earth-moving equipment.

  6. Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

    Science.gov (United States)

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study. PMID:24526899

  7. Study on tar generated from downdraft gasification of oil palm fronds.

    Science.gov (United States)

    Atnaw, Samson Mekbib; Kueh, Soo Chuan; Sulaiman, Shaharin Anwar

    2014-01-01

    One of the most challenging issues concerning the gasification of oil palm fronds (OPF) is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3) in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC) unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study.

  8. Study on Tar Generated from Downdraft Gasification of Oil Palm Fronds

    Directory of Open Access Journals (Sweden)

    Samson Mekbib Atnaw

    2014-01-01

    Full Text Available One of the most challenging issues concerning the gasification of oil palm fronds (OPF is the presence of tar and particulates formed during the process considering its high volatile matter content. In this study, a tar sampling train custom built based on standard tar sampling protocols was used to quantify the gravimetric concentration of tar (g/Nm3 in syngas produced from downdraft gasification of OPF. The amount of char, ash, and solid tar produced from the gasification process was measured in order to account for the mass and carbon conversion efficiency. Elemental analysis of the char and solid tar samples was done using ultimate analysis machine, while the relative concentration of the different compounds in the liquid tar was determined making use of a liquid gas chromatography (GC unit. Average tar concentration of 4.928 g/Nm3 and 1.923 g/Nm3 was obtained for raw gas and cleaned gas samples, respectively. Tar concentration in the raw gas sample was found to be higher compared to results for other biomass materials, which could be attributed to the higher volatile matter percentage of OPF. Average cleaning efficiency of 61% which is comparable to that of sand bed filter and venturi scrubber cleaning systems reported in the literature was obtained for the cleaning system proposed in the current study.

  9. Topical tar: Back to the future

    Energy Technology Data Exchange (ETDEWEB)

    Paghdal, K.V.; Schwartz, R.A. [University of Medicine & Dentistry of New Jersey, Newark, NJ (United States)

    2009-08-15

    The use of medicinal tar for dermatologic disorders dates back to the ancient times. Although coal tar is utilized more frequently in modern dermatology, wood tars have also been widely employed. Tar is used mainly in the treatment of chronic stable plaque psoriasis, scalp psoriasis, atopic dermatitis, and seborrheic dermatitis, either alone or in combination therapy with other medications, phototherapy, or both. Many modifications have been made to tar preparations to increase their acceptability, as some dislike its odor, messy application, and staining of clothing. One should consider a tried and true treatment with tar that has led to clearing of lesions and prolonged remission times. Occupational studies have demonstrated the carcinogenicity of tar; however, epidemiologic studies do not confirm similar outcomes when used topically. This article will review the pharmacology, formulations, efficacy, and adverse effects of crude coal tar and other tars in the treatment of selected dermatologic conditions.

  10. Catalytic Steam Reforming of Gasifier Tars: On-Line Monitoring of Tars with a Transportable Molecular-Beam Mass Spectrometer; Milestone Completion Report

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.; Ratcliff, M.; Dayton, D.

    2002-05-01

    of the tar conversion. The gas composition changes were monitored by two identical gas chromatographs (GCs), and modified method 5 sampling was performed to obtain gravimetric conversion data. The combination of these analytical techniques provided definitive catalyst performance data, as well as linkage to previous and on-going work elsewhere. Two catalysts were tested: nickel (Ni) on potassium promoted alumina (Sued-Chemie C11-NK), used commercially for naphtha steam reforming, and alumina (Battelle's DN34) claimed to be effective for gasifier tar decomposition. In addition, sand was tested as an inert reference material.

  11. Tar Creek study, Sargent oil field, Santa Clara County, California

    Science.gov (United States)

    Wagner, David L.; Fedasko, Bill; Carnahan, J.R.; Brunetti, Ross; Magoon, Leslie B.; Lillis, Paul G.; Lorenson, T.D.; Stanley, Richard G.

    2002-01-01

    Field work in the Tar Creek area of Sargent oil field was performed June 26 to 28, 2000. The Santa Clara County study area is located in Sections, 30, 31, and 32, Township 11 South, Range 4 East, M.D.B&M; and in Sections 25 and 36, Township 11 South, Range 3 East, M.D.B.&M., north and south of Tar Creek, west of Highway 101. The work was a cooperative effort of the California Department of Conservation's Division of Oil, Gas, and Geothermal Resources (DOGGR), California Geological Survey (CGS), and the United States Geological Survey (USGS). The purpose of the project was to map the stratigraphy and geologic structure (David Wagner, CGS); sample oil for age dating (Les Magoon, USGS); and search for undocumented wells plus conduct a GPS survey of the area (Bill Fedasko, J.P. Carnahan, and Ross Brunetti, DOGGR)

  12. 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....

  13. Application des fluides supercritiques à la production d'hydrocarbures. Exploitation des gisements par récupération assistée et applications diverses : pétrole, sables, schistes, charbons Application of Supercritical Fluids to Hydrocarbon Production. Enhanced Oi Recovery and Miscellaneous Applications: Oil, Tar Sands, Shales, Coals

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    dioxide. This article briefly describes the ranges of application and the thermodynamic mechanisms involved. Sources of available supercritical fluids in the vicinity of oil fields are quickly reviewed together with various operational problems. In addition to being used for enhanced recovery, supercritical fluids are also involved in various refining and extraction processes. The first industrial application was the process for deasphalting heavy petroleum fractions in 1956, making use of the great variations in the solvent power of a fluid in the vicinity of its critical point. This process has received revived interest in recent years because of the energy saving it entails. Likewise, oil shales, tar sands and coals, which are appreciable hydrocarbon sources for the future, are fields of potential applications for supercritical fluids. Specific processes are reviewed, most of which are undergoing pilot-plant development.

  14. Tropospheric Emission Spectrometer (TES) Satellite Validations of Ammonia, Methanol, Formic Acid, and Carbon Monoxide over the Canadian Oil Sands

    Data.gov (United States)

    U.S. Environmental Protection Agency — The URLs link to the data archive of the Troposphere Emission Spectrometer (TES) retrievals. These include the transects included in the Canadian Tar Sands study. A...

  15. Traditional Tar Production from the Anatolian Black Pine [Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe var. pallasiana] and its usages in Afyonkarahisar, Central Western Turkey.

    Science.gov (United States)

    Arı, Süleyman; Kargıoğlu, Mustafa; Temel, Mehmet; Konuk, Muhsin

    2014-03-27

    Tar is one example of a plant product used in folk medicine and it is obtained from Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe, which is very common in the West Anatolian Region. Old trees that are good for kindling and have thick trucks are preferred to obtain tar. Tar is used not only as traditional medicine but also for protection against both endoparasites and ectoparasites. The objective of this study was to record the traditional method of obtaining tar and its usages in Afyonkarahisar which is located in the Western Anatolian Region of Turkey. In order to record the traditional methods of obtaining tar, we visited the villages of Doğlat, Kürtyurdu and Çatağıl in Afyonkarahisar (Turkey) June-July, 2012. Ethnobotanical data about the method of collection and traditional usages of tar were obtained through informal interviews with 26 participants (16 men and 10 women). Data concerning the method of tar collection and its traditional usages were recorded and photographed. The traditional method for obtaining tar from Pinus nigra subsp. pallasiana by local people was recorded and the local usages (curing ear pain in children, osteomyelitis, wounds, ulcers, eczema, acne, alopecia, fungus, foot-and-mouth disease in animals, mouth sores in sheep and goats, protection against endo- and ectoparasites, repellent for snakes, mice, flies (Tabanus bovinus) and ticks, and the prevention of water leakage from roofs) of tar are described. In this study, the traditional method for obtaining tar and the traditional usages of tar are explained. Documentation of the method of obtaining tar and its traditional usages may contribute to scientific research on the benefits and usages of tar in medicine, veterinary medicine, as well as other fields.

  16. Sydney Tar Ponds Remediation: Experience to China

    Science.gov (United States)

    Liu, Fan; Bryson, Ken A.

    2009-01-01

    The infamous "Sydney Tar Ponds" are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief…

  17. Coal tar: past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Thami, G.P.; Sarkar, R. [Government Medical College & Hospital, Chandigarh (India). Dept. of Dermatology & Venerology

    2002-03-01

    Crude coal tar has been used in the treatment of dermatoses for many decades. In the last few years its use has been limited to skin diseases such as psoriasis and chronic dermatitis. Newer topical modalities for psoriasis are being used increasingly for treatment, but have failed to replace crude coal tar as a first-line treatment of psoriasis. The authors review the pharmacology, chemistry and use of crude coal tar in order to reappraise its role as a therapeutic agent in dermatology.

  18. Cancer fear over coal tar products

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    Discusses a report by Dutch researchers which suggests that the regular use of coal tar shampoos may significantly increase the risk of cancer due to the high levels of polynuclear aromatic hydrocarbons (PAHs) in the products. The PAH exposure of volunteers using a coal tar anti-dandruff shampoo was studied by measuring the amount of hydroxypyrene, a PAH breakdown product in their urine. Volunteers who had used the shampoo excreted high levels of hydroxypyrene the day after exposure. Excretion by the control group using a non-coal tar anti-dandruff shampoo remained constant. 1 ref., 1 fig.

  19. Characterization of acid tar waste from benzol purification | Danha ...

    African Journals Online (AJOL)

    The use of concentrated sulphuric acid to purify benzene, toluene and xylene produces acidic waste known as acid tar. The characterization of the acid tar to determine the composition and physical properties to device a way to use the waste was done. There were three acid tars two from benzene (B acid tar), toluene and ...

  20. Oil sands fever : the environmental implications of Canada's oil sands rush

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, D.; Severson-Baker, C.; Raynolds, M.

    2005-11-01

    This report puts forward recommendations to improve the environmental management of oil sands while calling for an accelerated transition towards sustainable energy in Canada. It presents a historical discussion and background of Canada's oil sands rush and discusses making oil from tar, fuel consumption by oil sand operations, and transportation to refineries. Climate change consequences such as escalating greenhouse gas emissions, emissions intensity, the Kyoto commitment and taking meaningful action are identified along with the cumulative environmental impacts on water, land and air. The paper addressed the issue of managing these cumulative impacts and protecting the environment. Government assistance and subsidies were discussed with reference to Alberta's favourable royalty regime and federal tax breaks. Last, the report discussed stewardship and leadership for responsible oil sand use, climate protection, regional environment protection and establishment of an equitable fiscal regime. 266 refs., 7 tabs., 34 figs.

  1. Northern Sand Sea

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form. This VIS image was taken at 82 degrees North latitude during Northern spring. The image is completely dominated by dunes. In sand seas, it is very common for a single type of dune to occur, and for a single predominate wind to control the alignment of the dunes. Image information: VIS instrument. Latitude 82.2, Longitude 152.5 East (207.5 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  2. Atlas of Dutch drift sands

    Science.gov (United States)

    Riksen, Michel; Jungerius, Pieter

    2013-04-01

    occurrences associated with push moraines show that drift sand occurs in elongated cells that are parallel to the prevailing SW wind. Their internal structure reflects the characteristic sequence of geomorphological processes: deflation dominant in the south-west, transport and accumulation towards the north east. Literature • Jungerius, P.D., Riksen, M.J.P.M., 2010. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt. Baltica 23, 1: 59-70. • Koster EA. 2005. Aeolian environments. In The physical Geography of Western Europe, Koster EA (ed). Oxford Regional Environments, Oxford University Press;139-160.

  3. Tar Management and Recycling in Biomass Gasification and Syngas Purification

    Science.gov (United States)

    McCaffrey, Zach

    Removal of tars is critical to the design and operation of biomass gasification systems as most syngas utilization processing equipment (e.g. internal combustion engines, gas turbines, fuel cells, and liquid fuel synthesis reactors) have a low tolerance for tar. Capturing and disposal of tar is expensive due to equipment costs, high hazardous waste disposal costs where direct uses cannot be found, and system energy losses incurred. Water scrubbing is an existing technique commonly used in gasification plants to remove contaminants and tar; however using water as the absorbent is non-ideal as tar compounds have low or no water solubility. Hydrophobic solvents can improve scrubber performance and this study evaluated tar solubility in selected solvents using slip-streams of untreated syngas from a laboratory fluidized bed reactor operated on almond composite feedstock using both air and steam gasification. Tar solubility was compared with Hansen's solubility theory to examine the extent to which the tar removal can be predicted. As collection of tar without utilization leads to a hazardous waste problem, the study investigated the effects of recycling tars back into the gasifier for destruction. Prior to experiments conducted on tar capture and recycle, characterizations of the air and steam gasification of the almond composite mix were made. This work aims to provide a better understanding of tar collection and solvent selection for wet scrubbers, and to provide information for designing improved tar management systems for biomass gasification.

  4. ANALYSIS OF COAL TAR COMPOSITIONS PRODUCED FROM SUB-BITUMINOUS KALIMANTAN COAL TAR

    Directory of Open Access Journals (Sweden)

    Dewi Selvia Fardhyanti

    2016-10-01

    Full Text Available Coal tar is a liquid by-product of coal pyrolysis processes. This liquid oil mixture contains various kind of useful compounds such as benzoic aromatic compounds and phenolic compounds. These compounds are widely used as raw material for insecticides, dyes, medicines, perfumes, coloring matters, and many others. The coal tar was collected by pyrolysis process of coal obtained from PT Kaltim Prima Coal and Arutmin-Kalimantan. The experiments typically occurred at the atmospheric pressure in a laboratory furnace at temperatures ranging from 300 to 550oC with a heating rate of 10oC/min and a holding time of 1 hour at the pyrolysis temperature. The Gas Chromatography-Mass Spectroscopy (GCMS was used to analyze the coal tar components. The obtained coal tar has the viscosity of 3.12 cp, the density of 2.78 g/cm3, the calorific value of 11,048.44 cal/g, and the molecular weight of 222.67. The analysis result showed that the coal tar contained more than 78 chemical compounds such as benzene, cresol, phenol, xylene, naphtalene, etc. The total phenolic compounds contained in coal tar is 33.25% (PT KPC and 17.58% (Arutmin-Kalimantan. The total naphtalene compounds contained in coal tar is 14.15% (PT KPC and 17.13% (ArutminKalimantan.

  5. Investigations into the effects of volatile biomass tar on the performance of Fe-based CLC oxygen carrier materials

    Science.gov (United States)

    Boot-Handford, Matthew E.; Florin, Nick; Fennell, Paul S.

    2016-11-01

    In this study we present findings from investigations into interactions between biomass tar and two iron based oxygen carrier materials (OCMs) designed for chemical-looping applications: a 100% Fe2O3 (100Fe) OCM and a 60 wt% Fe2O3/40 wt% Al2O3 (60Fe40Al) OCM. A novel 6 kWe two-stage, fixed-bed reactor was designed and constructed to simulate a chemical-looping combustion (CLC) process with ex situ gasification of biomass. Beech wood was pyrolysed in the first stage of the reactor at 773 K to produce a tar-containing fuel gas that was used to reduce the OCM loaded into the 2nd stage at 973 K. The presence of either OCM was found to significantly reduce the amount of biomass tars exiting the reactor by up to 71 wt% compared with analogous experiments in which the biomass tar compounds were exposed to an inert bed of sand. The tar cracking effect of the 60Fe40Al OCM was slightly greater than the 100Fe OCM although the reduction in the tar yield was roughly equivalent to the increase in carbon deposition observed for the 60Fe40Al OCM compared with the 100Fe OCM. In both cases, the tar cracking effect of the OCMs appeared to be independent of the oxidation state in which the OCM was exposed to the volatile biomass pyrolysis products (i.e. Fe2O3 or Fe3O4). Exposing the pyrolysis vapours to the OCMs in their oxidised (Fe2O3) form favoured the production of CO2. The production of CO was favoured when the OCMs were in their reduced (Fe3O4) form. Carbon deposition was removed in the subsequent oxidation phase with no obvious deleterious effects on the reactivity in subsequent CLC cycles with reduction by 3 mol% CO.

  6. Commentary: Human papillomavirus and tar hypothesis for ...

    Indian Academy of Sciences (India)

    2010-08-09

    Aug 9, 2010 ... Home; Journals; Journal of Biosciences; Volume 35; Issue 3. Commentary: Human papillomavirus and tar hypothesis for squamous cell cervical cancer. Christina Bennett Allen E Kuhn Harry W Haverkos. Volume 35 Issue 3 September 2010 pp 331-337 ...

  7. Influence of the presence of PAHs and coal tar on naphthalene sorption in soils

    Science.gov (United States)

    Bayard, Rémy; Barna, Ligia; Mahjoub, Borhane; Gourdon, Rémy

    2000-11-01

    concentrations (about 120 mg/kg) in the soil. In contrast, experiments carried out with coal tar particles revealed a significant effect. Naphthalene sorption appeared to be proportional to the amount of coal tar added to the sand or soil, and a much higher affinity of naphthalene for XOM ( Koc above 2000 cm 3/g) than SOM ( Koc around 300 cm 3/g) was observed. Naphthalene transport in the columns of sand or soil spiked with coal tar particles was simulated very satisfactorily with a dual double-domain model. Around 90% of naphthalene retention by coal tar was found to occur within the organic phase, suggesting a phase partition process which may be explained by the amorphous nature of the XOM and its extreme affinity for naphthalene. For SOM, however, which is present as porous microaggregates of clay and humic substances, with less affinity for naphthalene, only 1/3 of naphthalene retention was found to occur within the organic phase, underlining the significant role of surface adsorption in the short term behavior of naphthalene in soil. For longer contact times, the model simulations proposed in the present study should be coupled to slow sorption, aging and biodegradation models to describe long-term behavior of naphthalene in soil-tar-water systems.

  8. Sands styrke

    DEFF Research Database (Denmark)

    Jacobsen, H. Moust; Jørgensen, Mogens B.; Poulsen, H. Serup

    1975-01-01

    På grundlag af triaxialforsøg med D=7 og 20 cm og varierende højde på løse og faste lejringer af Blokhussand kan effekten af varierende højde-breddeforhold og spændingsniveau samt skalaeffekten bestemmes. Ved sammenligning med pladeforsøg med overfladelast op til 8 t/m2 kan den almindelige fremga...... fremgangsmåde ved bæreevneberegninger på sand undersøges....

  9. sand mold

    Science.gov (United States)

    Kovačević, Lazar; Terek, Pal; Miletić, Aleksandar; Kakaš, Damir

    2014-08-01

    Interfacial heat transfer coefficient at the metal-mold interface (IHTC) was estimated by an iterative algorithm based on the function specification method. An Al-9 wt% Si alloy plate casting was made in a sand mold prepared by CO2 process. Thermal history obtained from the experiment was used to solve an inverse heat conduction problem. Acquired transient IHTC values are then given in function of the casting surface temperature at the interface. By comparing the obtained results with previous findings, the influence of grain fineness number and consequently of mold roughness on maximum IHTC values is revealed.

  10. Design and engineering of west-side revetment for Tachibana Bay Power Station. Swelling behavior of sand compaction pile improved ground and mechanical properties of composite ground; Tachibanawan hatsudensho Nishigogan koji no sekkei to seko. Sand compaction pile kairyo jiban no moriagari kyodo to fukugo jiban no rikigaku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kameda, S.; Hara, J.; Ozaki, S. [Shikoku Electric Power Co., Inc., Kagawa (Japan)

    1997-07-05

    This report covers a sand compaction pile (SCP) process performed for the improvement of the sea bottom along the west-side revetment of the power station where a 10-odd meter thick sedimentary layer of soft clayey soil exists. Since the sea is only 5m deep in this area, an engineering method is chosen capable of minimizing the swelling of the ground, and changes in the physical properties of the composite ground that may affect the stability of the revetment are investigated. In this report, an estimating equation is proposed for accurately predicting the swelling, including the additional swelling of the ground already swollen, to result from the SCP-assisted improvement of the ground and a description is given of changes in composite ground mechanical properties induced by the SCP-assisted engineering work. A `one-directional construction system with one block constituted of three spans` is contrived. Furthermore, an estimating technique taking into account the secondary swelling is proposed. As the result, the apparent swelling rate agrees very well with the actual swelling rate. An SCP method with its capability enhanced may be established by considering time-dependent changes in the mechanical properties of the clayey soil between piles and their impact on the safety factor. 4 refs., 13 figs., 3 tabs.

  11. TAR-RNA recognition by a novel cyclic aminoglycoside analogue.

    Science.gov (United States)

    Raghunathan, Devanathan; Sánchez-Pedregal, Víctor M; Junker, Jochen; Schwiegk, Claudia; Kalesse, Markus; Kirschning, Andreas; Carlomagno, Teresa

    2006-01-01

    The formation of the Tat-protein/TAR-RNA complex is a crucial step in the regulation of human immunodeficiency virus (HIV)-gene expression. To obtain full-length viral transcripts the Tat/TAR complex has to recruit the positive transcription elongation factor complex (P-EFTb), which interacts with TAR through its cyclin T1 (CycT1) component. Mutational studies identified the TAR hexanucleotide loop as a crucial region for contacting CycT1. Interfering with the interaction between the Tat/CycT1 complex and the TAR-RNA is an attractive strategy for the design of anti-HIV drugs. Positively charged molecules, like aminoglycosides or peptidomimetics, bind the TAR-RNA, disrupting the Tat/TAR complex. Here, we investigate the complex between the HIV-2 TAR-RNA and a neooligoaminodeoxysaccharide by NMR spectroscopy. In contrast to other aminoglycosides, this novel aminoglycoside analogue contacts simultaneously the bulge residues required for Tat binding and the A35 residue of the hexanucleotide loop. Upon complex formation, the loop region undergoes profound conformational changes. The novel binding mode, together with the easy accessibility of derivatives for the neooligoaminodeoxysaccharide, could open the way to the design of a new class of TAR-RNA binders, which simultaneously inhibit the formation of both the Tat/TAR binary complex and the Tat/TAR/CycT1 ternary complex by obstructing both the bulge and loop regions of the RNA.

  12. Sand Diver

    Science.gov (United States)

    Scott, Alan J.

    2005-01-01

    A few years ago, I was preparing to teach a summer enrichment program for middle school students at the University of Wisconsin-Stout. With swimming on the minds of most kids during the summer, I thought buoyancy would be a fun topic to discuss. An interesting way to introduce this concept is by discussing the beer-drinking balloonist who, in a lawn chair, floated to 11,000 feet above Los Angeles in 1997. However, I needed a hands-on project and was not about to go purchase some lawn chairs to duplicate this experiment. A simple submersible called the "Sand Diver" was designed and is now used as a hands-on activity for my introductory physics course.

  13. Receiving demulsifying agent from the acid tar

    Energy Technology Data Exchange (ETDEWEB)

    Nikitina, A.A.; Belyaeva, A.S.; Kunakova, R.V. [FGBIHE ' Ufa State Academy of Economics and Services' , Ufa (Russian Federation); Movsumzade, E.M. [FGBIHE ' Ufa State Petroleum Technological Univ.' , Ufa (Russian Federation); Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry

    2012-07-01

    The processing of wastes of petrochemical production makes it possible to reduce the price of produced commodity of petroleum products substantially. Bitumen, fuel oils, tars and other mixture of heavy organic compounds are widely used in road construction, in paint and cable industries, manufacture of roofing materials, are used as boiler and furnace fuel, fuel for marine diesel engines, raw material for the production of modifying additives, fillers, surfaceactive substances, etc. (orig.)

  14. It's in the sand

    OpenAIRE

    Mitchell, Clive

    2016-01-01

    Sand is sand isn’t it? Sand gets everywhere but rather than a nuisance it is a valuable, high-purity raw material. Clive Mitchell, Industrial Minerals Specialist at the British Geological Survey (BGS), talks us through what sand is, what it can be used for and how to find it. His exploration of sand takes us from the deserts of Arabia to the damp sand pits of Mansfield!

  15. 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).

  16. Sands at Gusev Crater, Mars

    Science.gov (United States)

    Cabrol, Nathalie A.; Herkenhoff, Kenneth; Knoll, Andrew H.; Farmer, Jack; Arvidson, Raymond; Grin, Edmond; Li, Ronxing; Fenton, Lori; Cohen, Barbara; Bell, James F.; Aileen Yingst, R.

    2014-05-01

    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).

  17. Demonstration of Tar Removal from Paving Equipment and Ground Vehicles

    Science.gov (United States)

    2011-05-12

    wiping. BUILDING STRONG®4 Problem/Relevance Several ground vehicles need tar removal as part of the regular maintenance at depots. Oil/ bitumen ...includes demonstration of the cleaning process to remove tar, asphalt and bitumen from the road paving spreaders and military ground vehicles at the...River Army Depot (TARDEC/TACOM), August 2010 Citrus-King Performed Better Simple Green foamed , effective in removing oils, grease and paint, but not tar

  18. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  19. Industrial sand and gravel

    Science.gov (United States)

    Dolley, T.P.

    2013-01-01

    Domestic production of industrial sand and gravel in 2012 was about 49.5 Mt (55 million st), increasing 13 percent compared with that of 2011. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

  20. Acid Tar Lagoons: Management and Recovery

    Science.gov (United States)

    Bohers, Anna; Hroncová, Emília; Ladomerský, Juraj

    2017-04-01

    This contribution presents the issue with possibility of definitive removal of dangerous environmental burden in Slovakia - serious historical problem of two acid tar lagoons. In relation to their removal, no technology has been found so far - technologically and economically suitable, what caused problems with its management. Locality Predajná is well known in Slovakia by its character of contrasts: it is situated in the picturesque landscape of National Park buffer zone of Nízke Tatry, on the other site it is contaminated by 229 211m3 of acid tar with its characteristics of toxicity, carcinogenicity, teratogenicity, mutagenicity and toxicity especially for animals and plants. Acid tar in two landfills with depth of 1m in case of the first lagoon and 9,5m in case of the second lagoon is a waste product derived from operation of Petrochema Dubová - refinery and petrochemical plant whose activity was to process the crude oil through processes of sulfonation and adsorption technology for producing lubricating and special oils, synthetic detergents and special white oils for cosmetic and medical purposes. A part of acid tar was incinerated in two incineration plats. Concentration of SO2 in combustion gases was too high and it was not possible to decrease it under the value of 2000 mg.mn-3 [LADOMERSKÝ, J. - SAMEŠOVÁ, D.: Reduction in sulfur dioxide emissions waste gases of incineration plant. Acta facultatis ecologiae. 1999, p. 217-223]. That is why it was necessary to put them out of operation. Later, because of public opposition it was not possible to build a new incineration plat corresponding to the state of the art. Even though actual Slovak and European legislative for protection of environment against such impacts, neither of tried methods - bio or non-biologic treatment methods - was proved as suitable for processing or for recovery in the reason of different factors admission: i.e. strong aggressivity, difficulty with handling because of its sludgy and

  1. Síndrome TAR con tetrafocomelia

    OpenAIRE

    Miscione, H.; Primono, C.

    1997-01-01

    El síndrome TAR es un estigma genético recesivo de baja incidencia dentro de la patología ortopédica infantil general. El objetivo de este trabajo es la presentación de aquellos pacientes en donde la impregnación del síndrome es completa. Estos niños tienen en común la trombocitopenia intensa durante los primeros años de la vida, la amelia bilateral de sus miembros superiores, la fusión femorotibial y la agenesia de tibia de distinto grado. A estos síntomas se suman algunas otr...

  2. 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...

  3. Selected constituents in the smoke of domestic low tar cigarettes

    Energy Technology Data Exchange (ETDEWEB)

    Griest, W. H.; Quincy, R. B.; Guerin, M. R.

    1977-12-01

    Thirty-two brands of domestic commercial low tar and nicotine cigarettes were analyzed for their production of tar, nicotine, nitrogen oxides (as nitric oxide), hydrogen cyanide, acrolein, carbon monoxide and carbon dioxide under standard analytical smoking conditions. Results are compared with published data for certain brands.

  4. 48 CFR Appendix to Part 1252 - Tar Matrix

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Tar Matrix Appendix to Part 1252 Federal Acquisition Regulations System DEPARTMENT OF TRANSPORTATION CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Pt. 1252, App. Appendix to Part 1252—Tar Matrix ER27DE05.000...

  5. Evaluation of Gravimetric Tar Determination in Particle Samples

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik B.; Bentzen, Jens Dall

    2000-01-01

    A comparison of tar determination of particles from a down-draft gasifier using soxhlet extractions (with anisole, dichloromethane and acetone) and pyrolysis of the particles.......A comparison of tar determination of particles from a down-draft gasifier using soxhlet extractions (with anisole, dichloromethane and acetone) and pyrolysis of the particles....

  6. Tar Removal from Biomass Producer Gas by Using Biochar

    DEFF Research Database (Denmark)

    Ravenni, Giulia; Henriksen, Ulrik Birk; Ahrenfeldt, Jesper

    2017-01-01

    The biomass-derived char (biochar) produced in the gasifier as a residue, is a potential solution for removing tars from producer gas. This work investigates the interaction between tar compounds and biochar. Residual biochar from a TwoStage gasifier was tested as bed material in a laboratory setup...

  7. DECOMPOSITION OF TARS IN MICROWAVE PLASMA – PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    Mateusz Wnukowski

    2014-07-01

    Full Text Available The paper refers to the main problem connected with biomass gasification - a presence of tar in a product gas. This paper presents preliminary results of tar decomposition in a microwave plasma reactor. It gives a basic insight into the construction and work of the plasma reactor. During the experiment, researches were carried out on toluene as a tar surrogate. As a carrier gas for toluene and as a plasma agent, nitrogen was used. Flow rates of the gases and the microwave generator’s power were constant during the whole experiment. Results of the experiment showed that the decomposition process of toluene was effective because the decomposition efficiency attained above 95%. The main products of tar decomposition were light hydrocarbons and soot. The article also gives plans for further research in a matter of tar removal from the product gas.

  8. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Borup, Marianne; Hedegaard, Jette

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development og the theory of building up pore pressure in sand, L. B. Ibsen 1993....

  9. Baskarp Sand No. 15

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Bødker, Lars Bødker

    The Soil Mechanics Laboratory has started performing tests with a new sand, Baskarp No 15. Baskarp No 15 is a graded sand from Sweden. The shapes of the largest grains are round, while the small grains have sharp edges. The main part of of Baskarp No 15 is quarts, but it also contains feldspar...... and biotit. Mainly the sand will be used for tests concerning the development of the theory of building up pore pressure in sand....

  10. Lund Sand No 0

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Jakobsen, Finn Rosendal

    During the last 15 years the Geotechnical Engineering Group (GEG) at Aalborg University has performed triaxial tests with a sand called Lund No 0. Lund No 0 is a graded sand from a gravel pit near Horsens in Denmark. For the classification of the sand the following tests have been performed: Sieve...

  11. Final Safety Assessment of Coal Tar as Used in Cosmetics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Coal Tar is a semisolid by-product obtained in the destructive distillation of bituminous coal, which functions in cosmetic products as a cosmetic biocide and denaturant-antidandruff agent is also listed as a function, but this is considered an over-the-counter (OTC) drug use. In 2002, Coal Tar was reported to the Food and Drug Administration (FDA) to be used in four formulations, all of which appear to be OTC drug products. Coal Tar is monographed by the FDA as Category I (safe and effective) OTC drug ingredient for use in the treatment of dandruff, seborrhoea, and psoriasis. Coal Tar is absorbed through the skin of animals and humans and is systemically distributed. Although the Cosmetic Ingredient Review (CIR) Expert Panel believes that Coal Tar use as an antidandruff ingredient in OTC drug preparations is adequately addressed by the FDA regulations, the Panel also believes that the appropriate concentration of use of Coal Tar in cosmetic formulations should be that level that does not have a biological effect in the user. Additional data needed to make a safety assessment include product types in which Coal Tar is used (other than as an OTC drug ingredient), use concentrations, and the maximum concentration that does not induce a biological effect in users.

  12. Atmospheric tar balls: aged primary droplets from biomass burning?

    Science.gov (United States)

    Tóth, A.; Hoffer, A.; Nyirő-Kósa, I.; Pósfai, M.; Gelencsér, A.

    2014-07-01

    Atmospheric tar balls are particles of special morphology and composition that are fairly abundant in the plumes of biomass smoke. These particles form a specific subset of brown carbon (BrC) which has been shown to play a significant role in atmospheric shortwave absorption and, by extension, climate forcing. Here we suggest that tar balls are produced by the direct emission of liquid tar droplets followed by heat transformation upon biomass burning. For the first time in atmospheric chemistry we generated tar-ball particles from liquid tar obtained previously by dry distillation of wood in an all-glass apparatus in the laboratory with the total exclusion of flame processes. The particles were perfectly spherical with a mean optical diameter of 300 nm, refractory, externally mixed, and homogeneous in the contrast of the transmission electron microscopy (TEM) images. They lacked any graphene-like microstructure and exhibited a mean carbon-to-oxygen ratio of 10. All of the observed characteristics of laboratory-generated particles were very similar to those reported for atmospheric tar-ball particles in the literature, strongly supporting our hypothesis regarding the formation mechanism of atmospheric tar-ball particles.

  13. Selective isolation of mammalian genes by TAR cloning.

    Science.gov (United States)

    Kouprina, Natalay; Larionov, Vladimir

    2006-05-01

    Transformation-associated recombination (TAR) cloning provides a unique tool for selective isolation of desired chromosome segments and full-size genes from complex genomes in the form of a circular yeast artificial chromosome (YAC) up to 250 kb in size. The method has a broad application for structural and functional genomics, long-range haplotyping, mutational analysis of gene families, characterization of chromosomal rearrangements, and evolutionary studies. This unit describes a procedure for gene isolation by TAR as well as a method for conversion of YAC-TAR isolates into a bacterial artificial chromosome (BAC) form.

  14. UTILIZATION OF AQUEOUS-TAR CONDENSATES FORMED DURING GASIFICATION

    Directory of Open Access Journals (Sweden)

    Anna Kwiecińska

    2016-11-01

    Full Text Available Gasification of solid fuels is an alternative process for energy production using conventional and renewable fuels. Apart from desired compounds, i.e. carbon oxide, hydrogen and methane, the produced gas contains complex organic (tars and inorganic (carbonizate, ammonia contaminants. Those substances, together with water vapor, condensate during cooling of the process gas, what results in the formation of aqueous-tar condensate, which requires proper methods of utilization. The management of this stream is crucial for commercialization and application of the gasification technology. In the paper the treatment of aqueous-tar condensates formed during biomass gasification process is discussed. The removal of tars from the stream was based on their spontaneous separation. The aqueous stream was subjected to ultrafiltration operated at different pressures. Such a treatment configuration enabled to obtain highly concentrated retentate, which could be recycled to the gasifier, and filtrate, which could be subjected to further treatment.

  15. Source identification of a tar residue from Mumbai Beach

    Digital Repository Service at National Institute of Oceanography (India)

    Kadam, A; Rokade, M.A

    A tar residue from Mumbai Beach, Maharashtra, India was matched with the suspected source sample from a tanker using UV, IR and GLC techniques. Negligible differences in several ratios of UV absorbances and ratios of infrared transmittances...

  16. Biomass Gasification — Primary Methods for Eliminating Tar

    Directory of Open Access Journals (Sweden)

    Martin Lisý

    2012-01-01

    Full Text Available This present paper deals with primary methods for reducing tar in biomass gasification, namely by feeding a natural catalyst into a fluidized bed. This method is verified using an experimental pilot plant.

  17. Biogeochemical gradients above a coal tar DNAPL

    Energy Technology Data Exchange (ETDEWEB)

    Scherr, Kerstin E., E-mail: kerstin.brandstaetter-scherr@boku.ac.at [University of Natural Resources and Life Sciences Vienna (BOKU), Department IFA-Tulln, Institute for Environmental Biotechnology, Konrad Lorenz Strasse 20, 3430 Tulln (Austria); Backes, Diana [University of Natural Resources and Life Sciences Vienna (BOKU), Department IFA-Tulln, Institute for Environmental Biotechnology, Konrad Lorenz Strasse 20, 3430 Tulln (Austria); Scarlett, Alan G. [University of Plymouth, Petroleum and Environmental Geochemistry Group, Biogeochemistry Research Centre, Drake Circus, Plymouth, Devon PL4 8AA (United Kingdom); Lantschbauer, Wolfgang [Government of Upper Austria, Directorate for Environment and Water Management, Division for Environmental Protection, Kärntner Strasse 10-12, 4021 Linz (Austria); Nahold, Manfred [GUT Gruppe Umwelt und Technik GmbH, Ingenieurbüro für Technischen Umweltschutz, Plesching 15, 4040 Linz (Austria)

    2016-09-01

    Naturally occurring distribution and attenuation processes can keep hydrocarbon emissions from dense non aqueous phase liquids (DNAPL) into the adjacent groundwater at a minimum. In a historically coal tar DNAPL-impacted site, the de facto absence of a plume sparked investigations regarding the character of natural attenuation and DNAPL resolubilization processes at the site. Steep vertical gradients of polycyclic aromatic hydrocarbons, microbial community composition, secondary water quality and redox-parameters were found to occur between the DNAPL-proximal and shallow waters. While methanogenic and mixed-electron acceptor conditions prevailed close to the DNAPL, aerobic conditions and very low dissolved contaminant concentrations were identified in three meters vertical distance from the phase. Comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS) proved to be an efficient tool to characterize the behavior of the present complex contaminant mixture. Medium to low bioavailability of ferric iron and manganese oxides of aquifer samples was detected via incubation with Shewanella alga and evidence for iron and manganese reduction was collected. In contrast, 16S rDNA phylogenetic analysis revealed the absence of common iron reducing bacteria. Aerobic hydrocarbon degraders were abundant in shallow horizons, while nitrate reducers were dominating in deeper aquifer regions, in addition to a low relative abundance of methanogenic archaea. Partial Least Squares – Canonical Correspondence Analysis (PLS-CCA) suggested that nitrate and oxygen concentrations had the greatest impact on aquifer community structure in on- and offsite wells, which had a similarly high biodiversity (H’ and Chao1). Overall, slow hydrocarbon dissolution from the DNAPL appears to dominate natural attenuation processes. This site may serve as a model for developing legal and technical strategies for the treatment of DNAPL-impacted sites where contaminant plumes are

  18. Zero VOC, Coal Tar Free Splash Zone Coating (SZC)

    Science.gov (United States)

    2011-09-01

    volatile organic compounds (VOC) content, hazardous air pollutants (HAP), and may also include hazardous pigment content. The coal tar epoxy also...VOCs, HAPs of methyl isobutyl ketone (MIBK) and xylene, and the pigment chromium oxide. Each coat of SSPC PS 11.01 contains 30% by weight coal tar...marketed a millable gum polysulfide known as the first synthetic rubber commercially made in the United States. Today, there are several liquid

  19. Environmentally Friendly Cleaners for Removing Tar from Metal Surfaces

    Science.gov (United States)

    2009-04-01

    Terpene Solvent degreaser. 11 Inland Technologies 401 East 27th Street Tacoma, WA 98421 inland@inladtech.com Teksol EP Hydrotreated heavy naptha...4molyoil@wwt.net #739 Citrol II Monocyclic Terpene Removes road tar from vehicles. 18 Selden Research Ltd Staden Business Park Staden Lane Buxton...Orange terpenes , Ethyl lacatate Removes tar Universal cleaner 26 Walter Surface Technologies J. Walter Inc. 810 Day Hill Road Windsor, CT 06095

  20. Atmospheric tar balls: Particles from biomass and biofuel burning

    Science.gov (United States)

    Pósfai, MiháLy; GelencséR, AndráS.; Simonics, RenáTa; Arató, Krisztina; Li, Jia; Hobbs, Peter V.; Buseck, Peter R.

    2004-03-01

    "Tar balls" are amorphous, carbonaceous spherules that occur in the tropospheric aerosol as a result of biomass and biofuel burning. They form a distinct group of particles with diameters typically between 30 and 500 nm and readily identifiable with electron microscopy. Their lack of a turbostratic microstructure distinguishes them from soot, and their morphology and composition (˜90 mol % carbon) renders them distinct from other carbonaceous particles. Tar balls are particularly abundant in slightly aged (minutes to hours old) biomass smoke, indicating that they likely form by gas-to-particle conversion within smoke plumes. The material of tar balls is initially hygroscopic; however, the particles become largely insoluble as a result of free radical polymerization of their organic molecules. Consequently, tar balls are primarily externally mixed with other particle types, and they do not appreciably increase in size during aging. When tar balls coagulate with water-bearing particles, their material may partly dissolve and no longer be recognizable as distinct particles. Tar balls may contain organic compounds that absorb sunlight. They are an important, previously unrecognized type of carbonaceous (organic) atmospheric particle.

  1. Absorptive removal of biomass tar using water and oily materials.

    Science.gov (United States)

    Phuphuakrat, Thana; Namioka, Tomoaki; Yoshikawa, Kunio

    2011-01-01

    Water is the most common choice of absorption medium selected in many gasification systems. Because of poor solubility of tar in water, hydrophobic absorbents (diesel fuel, biodiesel fuel, vegetable oil, and engine oil) were studied on their absorption efficiency of biomass tar and compared with water. The results showed that only 31.8% of gravimetric tar was removed by the water scrubber, whereas the highest removal of gravimetric tar was obtained by a vegetable oil scrubber with a removal efficiency of 60.4%. When focusing on light PAH tar removal, the absorption efficiency can be ranked in the following order; diesel fuel>vegetable oil>biodiesel fuel>engine oil>water. On the other hand, an increase in gravimetric tar was observed for diesel fuel and biodiesel fuel scrubbers because of their easy evaporation. Therefore, the vegetable oil is recommended as the best absorbent to be used in gasification systems. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Oil shales and tar sands: a bibliography. Supplement 2, Parts 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Grissom, M.C. (ed.)

    1984-07-01

    This bibliography includes 4715 citations arranged in the broad subject categories: reserves and exploration; site geology and hydrology; drilling, fracturing, and mining; oil production, recovery, and refining; properties and composition; direct uses and by-products; health and safety; marketing and economics; waste research and management; environmental aspects; regulations; and general. There are corporate, author, subject, contract number, and report number indexes.

  3. Turbine Fuels from Tar Sands Bitumen and Heavy Oil. Phase I. Preliminary Process Analysis.

    Science.gov (United States)

    1985-04-09

    attractive feed to the FCC, as gasoline yields are low and dry gas yields are high. Therefore, gas oil pre- treater effluent is distilled to prepare a >650°F...gasoline blending or aromatics production, in addition to the JP-8. Figure 11 represents the principal flow scheme for the naphtha hydro- treaters ...and ammonia, may in- clude a significant amount of hydrogen. In addition, the light hydro- carbons - methane through propane - can be converted to

  4. Aviation Turbine Fuels from Tar Sands Bitumen and Heavy Oils. Part 3. Laboratory Sample Production.

    Science.gov (United States)

    1987-12-01

    OF temperature, degrees Fahrenheit FCC fluid catalytic cracker or cracking FOE fuel oil equivalent gm gram Hg mercury Hr hour IBP initial boiling...DILUENT PREPARATION - BLENDED GAS OIL/BITUMEN CRACKING RESULTS.........8 3. DILUENT PREPARATION HYDROTREATING SUMMARY..................10 4. LOOP 1...18 10. LOOP 2 HYDROTREATER RESULTS SUMMARY. .......... 19 11. DIOLEFIN SATURATION - HYDROTREATMENT OF THE LIGHT NAPHTHA ........... 23 12. JP-8

  5. Turbine Fuels from Tar Sands Bitumen and Heavy Oil. Part 2. Phase II. Laboratory Sample Production.

    Science.gov (United States)

    1986-05-01

    catalytic hydrotreating or hydrocracking of the resultant naphtha or distillate fractions. Four different feed- stocks were employed; two were bituoiens...process and two hydrogen addition type processes: 3) hydrovisbreaking and 4) fixed bed catalytic hydro- cracking . Refining processes employed to achieve...turbine fuels includes several catalytic processes in the downstream section of the refinery. As shown in Figure 1, the naphtha fraction undergoes

  6. Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance.

    Directory of Open Access Journals (Sweden)

    Solmaz Sobhanifar

    2016-12-01

    Full Text Available In recent years, there has been a growing interest in teichoic acids as targets for antibiotic drug design against major clinical pathogens such as Staphylococcus aureus, reflecting the disquieting increase in antibiotic resistance and the historical success of bacterial cell wall components as drug targets. It is now becoming clear that β-O-GlcNAcylation of S. aureus wall teichoic acids plays a major role in both pathogenicity and antibiotic resistance. Here we present the first structure of S. aureus TarS, the enzyme responsible for polyribitol phosphate β-O-GlcNAcylation. Using a divide and conquer strategy, we obtained crystal structures of various TarS constructs, mapping high resolution overlapping N-terminal and C-terminal structures onto a lower resolution full-length structure that resulted in a high resolution view of the entire enzyme. Using the N-terminal structure that encapsulates the catalytic domain, we furthermore captured several snapshots of TarS, including the native structure, the UDP-GlcNAc donor complex, and the UDP product complex. These structures along with structure-guided mutants allowed us to elucidate various catalytic features and identify key active site residues and catalytic loop rearrangements that provide a valuable platform for anti-MRSA drug design. We furthermore observed for the first time the presence of a trimerization domain composed of stacked carbohydrate binding modules, commonly observed in starch active enzymes, but adapted here for a poly sugar-phosphate glycosyltransferase.

  7. 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.

  8. Tar Production from Biomass Pyrolysis in a Fluidized Bed Reactor: A Novel Turbulent Multiphase Flow Formulation

    Science.gov (United States)

    Bellan, J.; Lathouwers, D.

    2000-01-01

    A novel multiphase flow model is presented for describing the pyrolysis of biomass in a 'bubbling' fluidized bed reactor. The mixture of biomass and sand in a gaseous flow is conceptualized as a particulate phase composed of two classes interacting with the carrier gaseous flow. The solid biomass is composed of three initial species: cellulose, hemicellulose and lignin. From each of these initial species, two new solid species originate during pyrolysis: an 'active' species and a char, thus totaling seven solid-biomass species. The gas phase is composed of the original carrier gas (steam), tar and gas; the last two species originate from the volumetric pyrolysis reaction. The conservation equations are derived from the Boltzmann equations through ensemble averaging. Stresses in the gaseous phase are the sum of the Newtonian and Reynolds (turbulent) contributions. The particulate phase stresses are the sum of collisional and Reynolds contributions. Heat transfer between phases, and heat transfer between classes in the particulate phase is modeled, the last resulting from collisions between sand and biomass. Closure of the equations must be performed by modeling the Reynolds stresses for both phases. The results of a simplified version (first step) of the model are presented.

  9. Modelling sand wave variation

    NARCIS (Netherlands)

    Sterlini-Van der Meer, Fenneke

    2009-01-01

    The sea floor of shallow seas is rarely flat and often dynamic. A widely occurring bedform type is the sand wave. Sand waves form more or less regular wavelike patterns on the seabed with crests up to one third of the water depth, wave lengths of hundreds of metres and a migration rate of metres up

  10. Sands cykliske styrke

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo

    1992-01-01

    Sands cykliske styrke kan beskrives ved Cyclic Liquefaction, Mobilisering, Stabilization og Instant Stabilization. I artiklen beskrives hvorfor Stabilization og Instant Stabilization ikke observeres, når sands udrænede styrke undersøges i triaxial celler, der anvender prøver med dobbelt prøvehøjde....

  11. Probing interaction of a fluorescent ligand with HIV TAR RNA

    Science.gov (United States)

    Qi, Liang; Zhang, Jing; He, Tian; Huo, Yuan; Zhang, Zhi-Qi

    2017-02-01

    Trans-activator of Transcription (Tat) antagonists could block the interaction between Tat protein and its target, trans-activation responsive region (TAR) RNA, to inhibit Tat function and prevent human immunodeficiency virus type 1 (HIV-1) replication. For the first time, a small fluorescence ligand, ICR 191, was found to interact with TAR RNA at the Tat binding site and compete with Tat. It was also observed that the fluorescence of ICR 191 could be quenched when binding to TAR RNA and recovered when discharged via competition with Tat peptide or a well-known Tat inhibitor, neomycin B. The binding parameters of ICR 191 to TAR RNA were determined through theoretical calculations. Mass spectrometry, circular dichroism and molecular docking were used to further confirm the interaction of ICR 191 with TAR RNA. Inspired by these discoveries, a primary fluorescence model for the discovery of Tat antagonists was built using ICR 191 as a fluorescence indicator and the feasibility of this model was evaluated. This ligand-RNA interaction could provide a new strategy for research aimed at discovering Tat antagonists.

  12. Thermocatalytic treatment of biomass tar model compounds via radio frequency.

    Science.gov (United States)

    Anis, Samsudin; Zainal, Z A; Bakar, M Z A

    2013-05-01

    A new effective RF tar thermocatalytic treatment process with low energy intensive has been proposed to remove tar from biomass gasification. Toluene and naphthalene as biomass tar model compounds were removed via both thermal and catalytic treatment over a wide temperature range from 850 °C to 1200 °C and 450 °C to 900 °C, respectively at residence time of 0-0.7 s. Thermal characteristics of the new technique are also described in this paper. This study clearly clarified that toluene was much easier to be removed than naphthalene. Soot was found as the final product of thermal treatment of the tar model and completely removed during catalytic treatment. Radical reactions generated by RF non-thermal effect improve the tar removal. The study showed that Y-zeolite has better catalytic activity compared to dolomite on toluene and naphthalene removal due to its acidic nature and large surface area, even at lower reaction temperature of about 550 °C. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. 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.

  14. Mars Rover Curiosity Traverses of Sand Ripples

    Science.gov (United States)

    Stein, N.; Arvidson, R. E.; Zhou, F.; Heverly, M.; Maimone, M.; Hartman, F.; Bellutta, P.; Iagnemma, K.; Senatore, C.

    2014-12-01

    Martian sand ripples present a challenge for rover mobility, with drives over ripples often characterized by high wheel sinkage and slippage that can lead to incipient embedding. Since landing in Gale Crater, Curiosity has traversed multiple sand ripples, including the transverse aeolian ridge (TAR) straddling Dingo Gap on sols 533 and 535. On sol 672, Curiosity crossed backward over a series of sand ripples before ending its drive after high motor currents initiated visual odometry (VO) processing, which detected 77% slip, well in excess of the imposed 60% slip limit. At the end of the drive, the right front wheel was deeply embedded at the base of a ripple flank with >20 cm sinkage and the rear wheels were near a ripple crest. As Curiosity continues its approach to Mount Sharp it will have to cross multiple ripples, and thus it is important to understand Curiosity's performance on sol 672 and over similar ripples. To this end the sol 672 drive was simulated in ARTEMIS (Adams-Based Rover Terramechanics Interaction Simulator), a software tool consisting of realistic rover mechanical models, a wheel-terrain interaction module for deformable and non-deformable surfaces, and realistic terrain models. ARTEMIS results, Dumont Dunes tests performed in the Mojave Desert using the Scarecrow test rover, and single wheel tests performed at MIT indicate that the high slip encountered on sol 672 likely occurred due to a combination of rover attack angle, ripple geometry, and soil properties. When ripple wavelength approaches vehicle length, the rover can reach orientations in which the leading wheels carry minimal normal loads and the trailing wheels sink deeply, resulting in high slippage and insufficient thrust to propel the rover over ripples. Even on relatively benign (i.e. low tilt) terrains, local morphology can impose high sinkage, thus impeding rover motion. Work is underway to quantify Curiosity's drive performance over various ripple geometries to retrieve soil

  15. Tar mats and residual oil distribution in a giant oil field offshore Abu Dhabi

    Energy Technology Data Exchange (ETDEWEB)

    Carpentier, Bernard [Institut Francais du Petrole and 4 Av. de Bois Preau, 92852 Rueil-Malmaison Cedex (France); Arab, Hani [ZADCO P.O. Box 46808, Abu Dhabi(United Arab Emirates); Pluchery, Eric; Chautru, Jean-Marc [Beicip-Franlab 232, Av. Napoleon Bonaparte, BP 213, 92502 Rueil-Malmaison Cedex (France)

    2007-09-15

    This paper describes how geochemical data (Rock Eval analysis, SARA composition) combined with wireline log interpretation allows for the recognition of the distribution and continuity of bitumens in a main reservoir of an offshore giant field in Abu Dhabi. The integration of new geochemical data with data and field information provided by the oil company ZADCO allows for the recognition of two types of bitumen rich levels in the main reservoir of the field: (a) one corresponding to bitumen rich main reservoir intervals associated with high resistivity and high oil saturation, these intervals can be called 'tar mats', (b) the other corresponding to low oil saturated intervals, and can be classified as 'heavy residual oil'. In terms of lateral and vertical distribution, the tar mats are found at the crestal area of the Present-day structure and are located at the base of the reservoir unit above a tight limestone which plays a role of being a vertical permeability barrier. The tar mats seem to be independent of the Present-day OWC and are not related to biodegradation processes. The heavy residual oil is mainly located in the Northeast and the Southeast parts of the field and close to the OWC but it is also present all around the field except (1) in the west, in the area of the spill point and (2) in the Northwest area where direct contact between mobile oil and water is detected. Study of the structural evolution demonstrates that a tilting of the field began at Dammam age time (Eocene). The tilting of the structure led to a reduction of the structural closure in the West followed by the leakage of part of the originally trapped oil. Numerical modeling of such a geological scenario leads to a distribution of fluids (water, movable oil and residual oil) very close to the one observed at Present-day time in the field. This modeling allows a prediction of the extension and distribution of the residual heavy oil within the studied reservoir and can

  16. Sand and Gravel Deposits

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset is a statewide polygon coverage of sand, gravel, and stone resources. This database includes the best data available from the VT Agency of Natural...

  17. Vestled - Hvide Sande

    DEFF Research Database (Denmark)

    Juel-Christiansen, Carsten; Hesselbjerg, Marianne; Schønherr, Torben

    2009-01-01

    Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side......Værket Vestled i Hvide Sande præsenteret i sammenhæng af 1000 nutidige landskabsarkitektoniske arbejder fra hele verden, hvor hvert værk vises på én side...

  18. 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.

  19. Inhibition of intercellular communication by condensates of high and low tar cigarettes

    DEFF Research Database (Denmark)

    Vang, Ole; Wallin, Håkan; Autrup, Herman

    1995-01-01

    condensates (CSC) and CSC fractions from high and low tar cigarettes was tested. CSC of both high and low tar cigarettes and fractions thereof contained tumor promoting activity. The tar yield of the cigarettes did not closely reflect the effects in the GJIC assay and the major constituent nicotine had...

  20. Experimental comparison of biomass chars with other catalysts for tar reduction

    NARCIS (Netherlands)

    Abu El-Rub, Ziad; Bramer, Eduard A.; Brem, Gerrit

    2008-01-01

    In this paper the potential of using biomass char as a catalyst for tar reduction is discussed. Biomass char is compared with other known catalysts used for tar conversion. Model tar compounds, phenol and naphthalene, were used to test char and other catalysts. Tests were carried out in a fixed bed

  1. Uptake of pyrene in a breast-fed child of a mother treated with coal tar.

    NARCIS (Netherlands)

    Scheepers, P.T.J.; Houtum, J.L.M. van; Anzion, R.B.M.; Harder, R.; Bos, R.P.; Valk, P.G.M. van der

    2009-01-01

    A woman was treated for atopic dermatitis with coal tar containing ointments. Coal tar containing ointments contain genotoxic polycyclic aromatic hydrocarbons. Over a period of 50 days the accumulated dose of different coal tar containing ointments treatments corresponded to 993 mg of pyrene and 464

  2. Literature Review on Possible Alternatives to Tar for Antiskid Layers

    NARCIS (Netherlands)

    Xiao, Y.

    2010-01-01

    In airports, there are different areas such as runways, taxiways, aprons and parking areas. For runways, good skid resistance and water drainage of the surface layer is necessary. Tar, because of its good adhesion properties and other advantages as mentioned above, is widely used in thin, high skid

  3. Extraction of Coal-tar Pitch by Supercritical Carbon Dioxide ...

    African Journals Online (AJOL)

    Several extractions of coal-tar pitch were performed using supercritical fluid carbon dioxide. The relationships between extraction yield during supercritical fluid extraction (SFE) and the variables temperature, pressure and extraction time were investigated. For qualitative and quantitative identification of organic compounds, ...

  4. Literature Review on Possible Alternatives to Tar for Antiskid Layers

    NARCIS (Netherlands)

    Xiao, Y.

    In airports, there are different areas such as runways, taxiways, aprons and parking areas. For runways, good skid resistance and water drainage of the surface layer is necessary. Tar, because of its good adhesion properties and other advantages as mentioned above, is widely used in thin, high skid

  5. Physical and chemical characterization of acid tar waste from crude ...

    African Journals Online (AJOL)

    Chemical analysis indicated the presence calcium, phosphorus and iron at 56.3, 15.7 and 11.3 ppm respectively with trace concentrations of lead, zinc, manganese and chromium. Organic analysis of the aromatic fraction of the acid tar waste by GC-MS revealed a wide range of compounds, including polycyclic aromatic ...

  6. Traditional African Religions (TARs): on HIV/AIDS, health and ...

    African Journals Online (AJOL)

    TARS being the custody of the survival strategies of living healthily on the. African continent, disregarding them, means that the African system of self-governance is destroyed. As a result, people do not seem to know how to handle their lives and are vulnerable to a lot of social evils, HIV/AIDS inclusive. This is because the ...

  7. GC/MS ANALYSIS OF COAL TAR COMPOSITION PRODUCED ...

    African Journals Online (AJOL)

    GC/MS ANALYSIS OF COAL TAR COMPOSITION PRODUCED FROM COAL PYROLYSIS. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work ...

  8. Pyrolysis kinetics of phenols from lignite semicoking tar

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Polovetskaya, O.S.; Proskuryakov, V.A.; Shavyrina, O.A. [Leo Tolstoy Tula State Pedag University, Tula (Russian Federation)

    2002-11-01

    The features of pyrolysis of phenols from lignite semicoking tar were studied. The activation energy and order of the reactions of accumulation of methane, hydrogen, carbon monoxide and dioxide, naphthalene and its methyl homologs, phenols, and isomeric cresols and dimethylphenols were determined.

  9. Phytotoxicity and Plant Productivity Analysis of Tar-Enriched Biochars

    Science.gov (United States)

    Keller, M. L.; Masiello, C. A.; Dugan, B.; Rudgers, J. A.; Capareda, S. C.

    2008-12-01

    Biochar is one of the three by-products obtained by the pyrolysis of organic material, the other two being syngas and bio-oil. The pyrolysis of biomass has generated a great amount of interest in recent years as all three by-products can be put toward beneficial uses. As part of a larger project designed to evaluate the hydrologic impact of biochar soil amendment, we generated a biochar through fast pyrolysis (less than 2 minutes) of sorghum stock at 600°C. In the initial biochar production run, the char bin was not purged with nitrogen. This inadvertent change in pyrolysis conditions produced a fast-pyrolysis biochar enriched with tars. We chose not to discard this batch, however, and instead used it to test the impact of tar-enriched biochars on plants. A suite of phytotoxicity tests were run to assess the effects of tar-rich biochar on plant germination and plant productivity. We designed the experiment to test for negative effects, using an organic carbon and nutrient-rich, greenhouse- optimized potting medium instead of soil. We used Black Seeded Simpson lettuce (Lactuca sativa) as the test organism. We found that even when tars are present within biochar, biochar amendment up to 10% by weight caused increased lettuce germination rates and increased biomass productivity. In this presentation, we will report the statistical significance of our germination and biomass data, as well as present preliminary data on how biochar amendment affects soil hydrologic properties.

  10. Optimizing tars valorization; Optimiser la valorisation des goudrons

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, V.

    2006-01-01

    BEFS-PEC, the engineering daughter company of IRH Environnement group (Mulhouse, France) has sold its tars distillation process, named Proabd, to the Chinese iron and steel company Shanxi Coking. This technology generates less pollution and reduces the energy consumption by 20%. Short paper. (J.S.)

  11. Brown carbon in tar balls from smoldering biomass combustion

    Science.gov (United States)

    R. K. Chakrabarty; H. Moosmuller; L.-W. A. Chen; K. Lewis; W. P. Arnott; C. Mazzoleni; M. K. Dubey; C. E. Wold; W. M. Hao; S. M. Kreidenweis

    2010-01-01

    We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Angstrom coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent...

  12. Wet scrubbing of biomass producer gas tars using vegetable oil

    Science.gov (United States)

    Bhoi, Prakashbhai Ramabhai

    The overall aims of this research study were to generate novel design data and to develop an equilibrium stage-based thermodynamic model of a vegetable oil based wet scrubbing system for the removal of model tar compounds (benzene, toluene and ethylbenzene) found in biomass producer gas. The specific objectives were to design, fabricate and evaluate a vegetable oil based wet scrubbing system and to optimize the design and operating variables; i.e., packed bed height, vegetable oil type, solvent temperature, and solvent flow rate. The experimental wet packed bed scrubbing system includes a liquid distributor specifically designed to distribute a high viscous vegetable oil uniformly and a mixing section, which was designed to generate a desired concentration of tar compounds in a simulated air stream. A method and calibration protocol of gas chromatography/mass spectroscopy was developed to quantify tar compounds. Experimental data were analyzed statistically using analysis of variance (ANOVA) procedure. Statistical analysis showed that both soybean and canola oils are potential solvents, providing comparable removal efficiency of tar compounds. The experimental height equivalent to a theoretical plate (HETP) was determined as 0.11 m for vegetable oil based scrubbing system. Packed bed height and solvent temperature had highly significant effect (p0.05) effect on the removal of model tar compounds. The packing specific constants, Ch and CP,0, for the Billet and Schultes pressure drop correlation were determined as 2.52 and 2.93, respectively. The equilibrium stage based thermodynamic model predicted the removal efficiency of model tar compounds in the range of 1-6%, 1-4% and 1-2% of experimental data for benzene, toluene and ethylbenzene, respectively, for the solvent temperature of 30° C. The NRTL-PR property model and UNIFAC for estimating binary interaction parameters are recommended for modeling absorption of tar compounds in vegetable oils. Bench scale

  13. Monitoring of tar contents in gases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Finn [ChimneyLab Europe ApS, Hadsten (Denmark); Houmann Jakobsen, H. [BioSynergi Proces ApS, Hoersholm (Denmark)

    2012-08-15

    The purpose of this project is to develop and test a relative cheap and simple online tar measuring method, which can monitor the tar content in product gas from thermal gasification. The measuring principle is absorption of tar from sample gas in Isopropanol (IPA), and measuring on this solution by UV-spectrophotometer. Continuous sampling of tar containing producer gas turned out to be a larger problem than earlier foreseen. The best solution was decided to be sampling with higher flows, and afterwards cleaning the IPA in activated carbon. The ambitions for continuous sampling had to be decreased to 1 week, where the IPA and the activated carbon is contaminated by tar and has to be replaced. However this requires larger amounts of IPA and activated carbon. For IPA the weekly consumption was 12-15 Litres and for activated carbon 10 Litres. The whole analyzer unit turned out to be more complex than first projected, mainly because of the increased amounts of IPA. The best mist filter, with respect to pressure drop, efficiency and retention time is a combination of glass wool and quarts wool. The unit has been tested on gas; 20 kW pellets burner for 116 hours. Harbooere updraft gasifier for 519 hours. Skive fluid bed gasifier for 879 hours. There have during the project period been several simple practical problems such as bubbles in the IPA, increasing pressure drop over the activated carbon bed, dropout of UV data acquisition program and increasing baseline. The principle showed from the beginning some good results, with the limitation of 1 week continuous operation, but at the 5. period in Skive the baseline was increasing all the time, and it was not possible to solve this problem. (LN)

  14. Ensamblajes urbanos: la TAR y el examen de la ciudad

    Directory of Open Access Journals (Sweden)

    Ignacio Farías

    2011-03-01

    Full Text Available Este artículo presenta nuevas perspectivas de investigación y desafíos analíticos que la teoría del actor-red (TAR abre para los estudios urbanos. En primer lugar, se revisan cómo los principios de relacionalidad híbrida y asociatividad plana de la TAR están siendo adoptados en los estudios urbanos para ampliar simétricamente la ecología urbana a no-humanos e impugnar concepciones escalares del espacio y economías urbanas. A continuación, se propone que la TAR trae consigo un desafío más fundamental relativo a la concepción de la ciudad como objeto de estudio. Mientras su comprensión habitual como objeto espacial, entidad político-económica y/o forma sociocultural subraya su carácter singular, estable y delimitado, la TAR permite pensar la ciudad como un objeto múltiple y decentrado. La noción de ensamblajes urbanos se introduce entonces para dar cuenta de la circulación y devenir de la ciudad en múltiples redes híbridas y translocales. El artículo concluye sopesando algunas de las consecuencias de este exámen de la ciudad, especialmente el reposicionamiento del problema de la complejidad, urbana en este caso, como punto, si no de partida, entonces al menos de llegada para la TAR.

  15. Hematite Outlier and Sand Dunes

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 4 December 2003This image shows a crater just south of the edge of the famous hematite-bearing surface, which is visible in the context image as a smooth area to the north. The crater has two features of immediate note. The first is a layered mound in the north part of the crater floor. This mound contains hematite, and it is an outlying remnant of the greater deposits to the north that have otherwise completely disappeared in this crater. The second feature is a dune field in the center of the crater floor, with dark dunes indicating winds from the northwest. The dunes grade into a dark sand sheet with no coherent structure, indicating that the sand layer thins out to the south and east.Image information: VIS instrument. Latitude -4.4, Longitude 357.3 East (2.7 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  16. The Thermal Cracking Experiment Research of Tar from Rice Hull Gasification for Power Generation

    Science.gov (United States)

    Wu, Z. S.; Mi, T.; We, Q. X.; Chen, Y. F.; Li, X. H.

    the tar from rice hull gasification for power generation which is cracked in high temperature is studied in this paper, the results reveal the part of compositions which have smaller RT in tar is first cracked into H2, CO2 and carbon, and then carbon react with H2 and CO2, and CH4, CO are formed; the cracked efficiency of tar can reach 28.66%, the carbon deposit among cracked tar can reach 12.76%, the results of the GC-MS analysis showed the aromatic extent of with tar cracking reaction carrying out in high temperature.

  17. Addressing airborne pollutant exposure at the source: an example of coal tar pitch volatiles (CTPV)

    CSIR Research Space (South Africa)

    Pretorius, Cecilia J

    2016-09-01

    Full Text Available (a)pyrene, Chrysene, Coal tar, Phenanthrene, pyrene • Terms may include: coal tar, coal tar pitch, and creosote to be coal tar products 3 BACKGROUND: PAHs • Largest portion of CTPV consist of polycyclic aromatic hydrocarbons (PAHs) • PAH content of coal tars... increases with increasing carbonisation temperature 4 BACKGROUND: PAHs 5 BACKGROUND: BaP • Benzo(a)pyrene: most toxic PAHs • Formed during incomplete combustion of coal, oil, gas, wood etc. • Previously used as marker for PAHs. Recently individual...

  18. The influence of partial oxidation mechanisms on tar destruction in TwoStage biomass gasification

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Egsgaard, Helge; Stelte, Wolfgang

    2013-01-01

    TwoStage gasification of biomass results in almost tar free producer gas suitable for multiple end-use purposes. In the present study, it is investigated to what extent the partial oxidation process of the pyrolysis gas from the first stage is involved in direct and in-direct tar destruction....... The resulting PAH tar compounds are readily converted in the subsequent char-bed of the TwoStage gasification process and the partial oxidation process thus contributes directly as well as in-directly to the overall tar destruction. A high temperature and excess air ratios contribute positively to the direct...... tar destruction and a high moisture content of the biomass enhances the decomposition of phenol and inhibits the formation of naphthalene. This enhances tar conversion and gasification in the char-bed, and thus contributes in-directly to the tar destruction....

  19. Source Zone Remediation of Tars at Former Manufactured Gas Plants Using Phyiscochemical Methods to Promote Mobilization

    Science.gov (United States)

    Birak, P. S.; Hauswirth, S.; Miller, C. T.

    2009-12-01

    Tars are a byproduct from gas manufacturing that are present in the subsurface at many former manufactured gas plants (FMGPs). These dense non-aqueous phase liquids are largely composed of polycyclic aromatic compounds, including several known carcinogens. Once below the water table, tars are particularly difficult to remediate due to their viscous nature and ability to alter system wettability. For this study, we investigate the feasibility of mobilizing tars as a means of source zone remediation. Tar samples were obtained from two FMGPs. We measured tar viscosity as a function of temperature using a rotational viscometer. Viscosity was found to be very sensitive to temperature and decreased by orders of magnitude from 5 to 80 degrees C. In one-dimensional column experiments, we examined the removal efficiency of tar by thermal methods and alkaline flushing, as well as, using a combination of methods. Sodium hydroxide solutions effectively mobilized the majority of the tar mass as a continuous phase.

  20. Bitumen recovery from oil sands using deep eutectic solvent and its aqueous solutions

    Science.gov (United States)

    Pulati, Nuerxida

    Oil sands compose a significant proportion of the world's known oil reserves. Oil sands are also known as tar sands and bituminous sands, are complex mixtures of sand, clays, water and bitumen, which is "heavy" and highly viscous oil. The extraction and separation of bitumen from oil sands requires significant amount of energy and large quantities of water and poses several environmental challenges. Bitumen can be successfully separated from oil sands using imidazolium based ionic liquids and nonpolar solvents, however, ionic liquids are expensive and toxic. In this thesis, the ionic liquid alternatives- deep eutectic solvent, were investigated. Oil sands separation can be successfully achieved by using deep eutectic solvents DES (choline chloride and urea) and nonpolar solvent naphtha in different types of oil sands, including Canadian ("water-wet"), Utah ("oil-wet") and low grade Kentucky oil sands. The separation quality depends on oil sands type, including bitumen and fine content, and separation condition, such as solvent ratio, temperature, mixing time and mechanical centrifuge. This separation claims to the DES ability to form ion /charge layering on mineral surface, which results in reduction of adhesion forces between bitumen and minerals and promote their separation. Addition of water to DES can reduce DES viscosity. DES water mixture as a media, oil sands separation can be achieved. However, concentration at about 50 % or higher might be required to obtain a clear separation. And the separation efficiency is oil sands sample dependent. The highest bitumen extraction yield happened at 75% DES-water solution for Utah oil sands samples, and at 50 60% DES-water solutions for Alberta oil sands samples. Force curves were measured using Atomic Force Microscopy new technique, PeakForce Tapping Quantitative Nanomechanical Mapping (PFTQNM). The results demonstrate that, by adding DES, the adhesion force between bitumen and silica and dissipation energy will

  1. The temporal relationship between advertising and sales of low‐tar cigarettes

    Science.gov (United States)

    Reed, Mark B; Anderson, Christy M; Burns, David M

    2006-01-01

    Objective and hypothesis To determine whether a temporal relationship exists between the advertising and sales of low‐tar cigarettes. It was hypothesised that increases in the advertising of low‐tar cigarettes would precede increases in sales for these cigarettes. Methods The themes of cigarette advertisements were reviewed and coded for 20 low‐tar cigarette brands advertised in 13 widely read magazines in the US between 1960 and 1996. These 20 brands represented most of the low‐tar cigarette advertisements and cigarette sales from 1967 to 1996. Cigarette sales data were obtained from the 1994 Maxwell report that summarises all cigarette sales from 1925 to 1990. If the advertisement referred to the low‐tar attributes of the cigarette advertised, the advertisement was coded as having a low‐tar theme and was included in the analysis. Results Five different graphical presentations of the relationship between the advertising and sales of the 20 low‐tar cigarette brands showed a temporal relationship between low‐tar advertising and sales for these brands. This relationship was observed for brands that introduced a low‐tar alternative into an existing brand family (eg, Marlboro Light) and for new exclusively low‐tar brands (eg, Carlton). Despite large increases in the advertising for the exclusively low‐tar brands, sales of these brands remained low relative to sales of the low‐tar alternative brands. Conclusions Increases in print advertising of 20 of the most popular low‐tar cigarette brands were followed by increases in sales for these cigarettes. Despite increases in the advertising of exclusively low‐tar brands in the mid‐1970s and early 1980s, the sales of these brands never matched the sales of the low‐tar alternative brands. This suggests that it may have been easier to get smokers to switch to low‐tar brands within a brand family compared with entirely new low‐tar brands. Over the past 30 years, the marketing of low‐tar

  2. The temporal relationship between advertising and sales of low-tar cigarettes.

    Science.gov (United States)

    Reed, Mark B; Anderson, Christy M; Burns, David M

    2006-12-01

    To determine whether a temporal relationship exists between the advertising and sales of low-tar cigarettes. It was hypothesised that increases in the advertising of low-tar cigarettes would precede increases in sales for these cigarettes. The themes of cigarette advertisements were reviewed and coded for 20 low-tar cigarette brands advertised in 13 widely read magazines in the US between 1960 and 1996. These 20 brands represented most of the low-tar cigarette advertisements and cigarette sales from 1967 to 1996. Cigarette sales data were obtained from the 1994 Maxwell report that summarises all cigarette sales from 1925 to 1990. If the advertisement referred to the low-tar attributes of the cigarette advertised, the advertisement was coded as having a low-tar theme and was included in the analysis. Five different graphical presentations of the relationship between the advertising and sales of the 20 low-tar cigarette brands showed a temporal relationship between low-tar advertising and sales for these brands. This relationship was observed for brands that introduced a low-tar alternative into an existing brand family (eg, Marlboro Light) and for new exclusively low-tar brands (eg, Carlton). Despite large increases in the advertising for the exclusively low-tar brands, sales of these brands remained low relative to sales of the low-tar alternative brands. Increases in print advertising of 20 of the most popular low-tar cigarette brands were followed by increases in sales for these cigarettes. Despite increases in the advertising of exclusively low-tar brands in the mid-1970s and early 1980s, the sales of these brands never matched the sales of the low-tar alternative brands. This suggests that it may have been easier to get smokers to switch to low-tar brands within a brand family compared with entirely new low-tar brands. Over the past 30 years, the marketing of low-tar cigarettes as a healthier alternative to higher-tar cigarettes has resulted in these brands

  3. 76 FR 57074 - Transfer of Administrative Jurisdiction at or Near Great Sand Dunes National Park

    Science.gov (United States)

    2011-09-15

    ... benefit of Great Sand Dunes National Park, Baca National Wildlife Refuge, and the Rio Grande National... Park Service Land Resources Program Center, Intermountain Region, 12795 West Alameda Parkway, Lakewood... 25287, 12795 West Alameda Parkway, Lakewood, Colorado 80225-0287. SUPPLEMENTARY INFORMATION: As...

  4. 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...

  5. Virksomhedens sande ansigt

    DEFF Research Database (Denmark)

    Lundholt, Marianne Wolff

    2017-01-01

    Er modhistorier en byrde eller en styrke i forandringsprocesser? Hvad stiller vi op, når adgangen til organisationens sande identitet går gennem medarbejdernes modhistorier? Når vi sammenholder denne erkendelse med vores viden om, at medarbejdere helt naturligt afholder sig fra at videregive disse...

  6. Speleothems and Sand Castles

    Science.gov (United States)

    Hance, Trevor; Befus, Kevin

    2015-01-01

    The idea of building sand castles evokes images of lazy summer days at the beach, listening to waves crash, enjoying salty breezes, and just unplugging for a while to let our inner child explore the wonderful natural toys beneath our feet. The idea of exploring caves might evoke feelings and images of claustrophobia or pioneers and Native…

  7. Sand Filter Technology

    Science.gov (United States)

    2016-08-01

    EXWC) performed the evaluation at the Naval Air Station Lemoore, CA . The two year evaluation period began with one year of sand filter operation...appear dirty? If you answered “ yes ” to the first question and “ yes ” to either of the other questions, investigate this technology for your

  8. Building with Sand

    Science.gov (United States)

    Ashbrook, Peggy

    2010-01-01

    Children playing in damp sand invariably try to make a tower or a tunnel. By providing experiences with a variety of materials, alone and together, teachers set up the conditions for children to learn through their senses and ensure that a class approaches a topic with a common set of experiences to build on. Learning about the properties of…

  9. Quantitative analysis of phenol and alkylphenols in Brazilian coal tar

    Directory of Open Access Journals (Sweden)

    Elina Bastos Caramão

    2004-04-01

    Full Text Available The main purpose of this work is the identification and quantification of phenolic compounds in coal tar samples from a ceramics factory in Cocal (SC, Brazil. The samples were subjected to preparative scale liquid chromatography, using Amberlyst A-27TM ion-exchange resin as stationary phase. The fractions obtained were classified as "acids" and "BN" (bases and neutrals. The identification and quantification of phenols, in the acid fraction, was made by gas chromatography coupled to mass spectrometry (GC/MS. Nearly twenty-five phenols were identified in the samples and nine of them were also quantified. The results showed that coal tar has large quantities of phenolic compounds of industrial interest.

  10. Evaluation of different oxygen carriers for biomass tar reforming

    DEFF Research Database (Denmark)

    Mendiara, Teresa; Johansen, Joakim Myung; Utrilla, Rubén

    2011-01-01

    This work is a continuation of a previous paper by the authors [1] which analyzed the suitability of the Chemical Looping technology in biomass tar reforming. Four different oxygen carriers were tested with toluene as tar model compound: 60% NiO/MgAl2O4 (Ni60), 40% NiO/NiAl2O4 (Ni40), 40% Mn3O4/Mg......–ZrO2 (Mn40) and FeTiO3 (Fe) and their tendency to carbon deposition was analyzed in the temperature range 873–1073K. In the present paper, the reactivity of these carriers to other compounds in the gasification gas is studied, also with special emphasis on the tendency to carbon deposition. Experiments...

  11. Evaluation of different oxygen carriers for biomass tar reforming

    DEFF Research Database (Denmark)

    Mendiara, Teresa; Johansen, Joakim Myung; Utrilla, Rubén

    2011-01-01

    , in a concentration of 600–2000ppmv, was chosen as a tar model compound. Experiments were performed in a TGA apparatus and a fixed bed reactor. Four oxygen carriers (60% NiO/MgAl2O4 (Ni60), 40% NiO/NiAl2O4 (Ni40), 40% Mn3O4/Mg–ZrO2 (Mn40) and FeTiO3 (Fe)) were tested under alternating reducing/oxidizing cycles....... Several variables affecting the reducing cycle were analyzed: temperature, time for the reduction step and H2O/C7H8 molar ratio. Ni40 and Mn40 presented interesting characteristics for CLR of biomass tar. Both showed stable reactivity to C7H8 after a few cycles. Ni40 showed a high tendency to carbon...

  12. Cold Preparation of Heroin in a Black Tar Market.

    Science.gov (United States)

    Roth, Alexis M; Armenta, Richard F; Wagner, Karla D; Strathdee, Steffanie A; Goldshear, Jesse L; Cuevas-Mota, Jazmine; Garfein, Richard S

    2017-07-29

    Black tar heroin is typically prepared for injection with heat which decreases the risk of HIV transmission by inactivating the virus. We received reports that persons who inject drugs (PWID) in Tijuana, Baja California, Mexico, a black tar heroin market, were using only water to dissolve heroin. Because Tijuana abuts San Diego County, CA, United States, we undertook the present analyses to determine the prevalence of this practice among PWID in San Diego, California. PWID completed quarterly behavioral assessments and serological testing for blood-borne viruses. Bivariate and multivariable logistic regression models were constructed to assess for individual, social, and structural correlates of preparing heroin without heat within the preceding 6 months. Nearly half of black tar heroin users (149/305) reported they had prepared heroin without heat within 6 months. In multivariable analysis, cold preparation was independently associated with younger age (10 year decrease; AOR = 1.25; 95% CI 1.03, 1.53), more drug injecting acquaintances (per 5 acquaintance increase; AOR = 1.05; 95% CI 1.01, 1.09) and prefilled syringe use (injecting drugs from syringes that are already filled with drugs before purchase; AOR = 1.86; 95% CI 1.14, 3.02). Conclusions/Importance: To our knowledge, this is the first paper to report that PWID living in a black tar heroin market are preparing heroin without heat. Additional research is needed to determine whether this is an endemic practice or PWID are engaging in new forms of drug preparation in response to changes in the environment.

  13. Zero VOC, Coal Tar Free Splash Zone Coating (SZC)

    Science.gov (United States)

    2010-12-01

    Operating Salt Spray (Fog) Apparatus D 476 Classification for Dry Pigmentary Titanium Dioxide Pigments D 512 Test Methods for Chloride Ion...system options include high VOC content, Hazardous Air Pollutants (HAP’s) and may also include hazardous pigment content. The coal tar epoxy also...Organic Compounds (VOC’s), Hazardous Air Pollutants (HAP’s) of Methyl Isobutyl Ketone (MIBK) and Xylene, and the pigment Chromium Oxide. Each coat of

  14. Triaxial tests in Fontainebleau sand

    DEFF Research Database (Denmark)

    Latini, Chiara; Zania, Varvara

    2016-01-01

    The purpose of this internal report is to examine the influence of relative density on the strength and deformation characteristics of Fontainebleau sand. Compression triaxial tests were performed on saturated sand samples with different densities and initial confining pressure. Note...

  15. Coal-tar based pavement sealant toxicity to freshwater macroinvertebrates.

    Science.gov (United States)

    Bryer, Pamela J; Scoggins, Mateo; McClintock, Nancy L

    2010-05-01

    Non-point-source pollution is a major source of ecological impairment in urban stream systems. Recent work suggests that coal-tar pavement sealants, used extensively to protect parking areas, may be contributing a large portion of the polycyclic aromatic hydrocarbon (PAH) loading seen in urban stream sediments. The hypothesis that dried coal-tar pavement sealant flake could alter the macroinvertebrate communities native to streams in Austin, TX was tested using a controlled outdoor laboratory type approach. The treatment groups were: control, low, medium, and high with total PAH concentrations (TPAH = sum of 16 EPA priority pollutant PAHs) of 0.1, 7.5, 18.4, & 300 mg/kg respectively. The low, medium, and high treatments were created via the addition of dried coal-tar pavement sealant to a sterile soil. At the start of the 24-day exposure, sediment from a minimally impacted local reference site containing a community of live sediment-dwelling benthic macroinvertebrates was added to each replicate. An exposure-dependent response was found for several stream health measures and for several individual taxa. There were community differences in abundance (P = 0.0004) and richness (P pavement sealants contain bioavailable PAHs that may harm aquatic environments. Copyright 2009 Elsevier Ltd. All rights reserved.

  16. Brown carbon in tar balls from smoldering biomass combustion

    Science.gov (United States)

    Chakrabarty, R. K.; Moosmüller, H.; Chen, L.-W. A.; Lewis, K.; Arnott, W. P.; Mazzoleni, C.; Dubey, M. K.; Wold, C. E.; Hao, W. M.; Kreidenweis, S. M.

    2010-07-01

    We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Ångström coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent imaginary part of its refractive index - optically defined as "brown carbon" - is an important component of tar balls. The spectrum of the imaginary parts of their complex refractive indices can be described with a Lorentzian-like model with an effective resonance wavelength in the ultraviolet (UV) spectral region. Sensitivity calculations for aerosols containing traditional OC (no absorption at visible and UV wavelengths) and brown carbon suggest that accounting for near-UV absorption by brown carbon leads to an increase in aerosol radiative forcing efficiency and increased light absorption. Since particles from smoldering combustion account for nearly three-fourths of the total carbonaceous aerosol mass emitted globally, inclusion of the optical properties of tar balls into radiative forcing models has significance for the Earth's radiation budget, optical remote sensing, and understanding of anomalous UV absorption in the troposphere.

  17. Brown carbon in tar balls from smoldering biomass combustion

    Directory of Open Access Journals (Sweden)

    R. K. Chakrabarty

    2010-07-01

    Full Text Available We report the direct observation of laboratory production of spherical, carbonaceous particles – "tar balls" – from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Ångström coefficients (AAC indicate that a class of light absorbing organic carbon (OC with wavelength dependent imaginary part of its refractive index – optically defined as "brown carbon" – is an important component of tar balls. The spectrum of the imaginary parts of their complex refractive indices can be described with a Lorentzian-like model with an effective resonance wavelength in the ultraviolet (UV spectral region. Sensitivity calculations for aerosols containing traditional OC (no absorption at visible and UV wavelengths and brown carbon suggest that accounting for near-UV absorption by brown carbon leads to an increase in aerosol radiative forcing efficiency and increased light absorption. Since particles from smoldering combustion account for nearly three-fourths of the total carbonaceous aerosol mass emitted globally, inclusion of the optical properties of tar balls into radiative forcing models has significance for the Earth's radiation budget, optical remote sensing, and understanding of anomalous UV absorption in the troposphere.

  18. 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...

  19. 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.

  20. Metal catalysts for steam reforming of tar derived from the gasification of lignocellulosic biomass.

    Science.gov (United States)

    Li, Dalin; Tamura, Masazumi; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-02-01

    Biomass gasification is one of the most important technologies for the conversion of biomass to electricity, fuels, and chemicals. The main obstacle preventing the commercial application of this technology is the presence of tar in the product gas. Catalytic reforming of tar appears a promising approach to remove tar and supported metal catalysts are among the most effective catalysts. Nevertheless, improvement of catalytic performances including activity, stability, resistance to coke deposition and aggregation of metal particles, as well as catalyst regenerability is greatly needed. This review focuses on the design and catalysis of supported metal catalysts for the removal of tar in the gasification of biomass. The recent development of metal catalysts including Rh, Ni, Co, and their alloys for steam reforming of biomass tar and tar model compounds is introduced. The role of metal species, support materials, promoters, and their interfaces is described. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Moving sand dunes

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    In several desert areas, the slow motion of sand dunes can be a challenge for modern human activities and a threat for the survival of ancient places or archaeological sites. However, several methods exist for surveying the dune fields and estimate their migration rate. Among these methods, the use of satellite images, in particular of those freely available on the World Wide Web, is a convenient resource for the planning of future human settlements and activities.

  2. Pembelajaran Ritme Menggunakan Alat Musik Tar Pada Siswa Kelas IX Di Mts Negeri 2 Pontianak

    OpenAIRE

    Wahyudi, Deki; Ghozali, Imam; Wartiningsih, Agus

    2014-01-01

    Rhythm Learning by Using Musical Instruments Tar. The background of this research is that many teachers have difficulty in selecting appropriate learning media in lesson learning the art of music, especially rhythm objective of these problems is the description of the application of learning rhythm using musical instruments tar in Class IX in MTs N 2 Pontianak, as well as knowing the results achieved in learning rhythm using musical instruments tar in Class IX MTs N 2 Pontianak. This type of ...

  3. Comprehensive database of Manufactured Gas Plant tars. Part B. Aliphatic and aromatic compounds.

    Science.gov (United States)

    Gallacher, Christopher; Thomas, Russell; Lord, Richard; Kalin, Robert M; Taylor, Chris

    2017-08-15

    Coal tars are a mixture of organic and inorganic compounds that were produced as a by-product from the manufactured gas and coke making industries. The composition of the tar produced varies depending on many factors; these include the temperature of production and the type of retort used. As different production processes produce different tars, a comprehensive database of the compounds present within coal tars from different production processes is a valuable resource. Such a database would help to understand how their chemical properties differ and what hazards the compounds present within these tars might pose. This study focuses on the aliphatic and aromatic compounds present in a database of 16 different tars from five different production processes. Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatised post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatised samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS). A total of 198 individual aliphatic and 951 individual aromatic compounds were detected within 16 tar samples produced by five different production processes. The polycyclic aromatic hydrocarbon (PAH) content of coal tars varies greatly depending on the production process used to obtain the tars and this is clearly demonstrated within the results. The aliphatic composition of the tars provided an important piece of analytical information that would have otherwise been missed with the detection of petrogenic compounds such as alkyl cyclohexanes. The aromatic compositions of the tar samples varied greatly between the different production processes investigated and useful analytical information was obtained about the individual production process groups. Alkyl cyclohexanes were detected in all samples from sites known to operate Carbureted Water Gas plants and not detected in

  4. Thermal Cracking of Tars in a Continuously Fed Reactor with Steam

    Science.gov (United States)

    2011-05-01

    coal and biomass) Oxygenated compounds (phenols and acids) TAR, oil, Naptha Pyrolysis gases (CO, H2, CH4, H2O, etc.) CHAR (carbon and inorganics...For updraft gasifiers or pyrolysis systems (usually high tar concentrations), it is possible to treat, reduce or convert these tars to more...13 min), 530 oC Where: X = 1- W / Wo Wo = Original wt. of sample (dry basis) W = Instantaneous wt. Bonus Slide – Pyrolysis of Paper

  5. 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

  6. Assessment of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

    Science.gov (United States)

    Hult, M.F.

    1984-01-01

    Operation of a coal-tar distillation and wood-preserving facility in St. Louis Park, Minnesota, during 1918-72 contaminated ground water with coal-tar derivatives and inorganic chemicals. Coal-tar derivatives entered the groundwater system through three major paths: (1) Spills and drippings that percolated to the water table, (2) surface runoff and plant process water that was discharged to wetlands south of the former plant site, and (3) movement of coal tar directly into bedrock aquifers through a multiaquifer well on the site.

  7. Dermal uptake of polycyclic aromatic hydrocarbons after hairwash with coal-tar shampoo

    Energy Technology Data Exchange (ETDEWEB)

    Schooten, F.-J. van; Moonen, E.J.C.; Rhijnsburger, E.; Agen, B. van; Thijssen, H.H.W.; Kleinjans, J.C.S. [University of Limburg, Maastricht (Netherlands). Dept. of Health Risk Analysis and Toxicology

    1994-11-26

    Describes an experiment to assess the dermal uptake of polycyclic aromatic hydrocarbons (PAHs) after hairwashing with coal tar antidandruff shampoo. The urinary excretion of 1-hydroxypyrene (1-OH-P), a PAH metabolile was used to assess internal dose of PAH. A single use of coal tar shampoo resulted in increased 1-OH-P excretion in all members of the experimental group compared with the control group using a non-coal tar antidandruff shampoo. It is suggested that repeated use of coal tar shampoo would result in a high internal dose of carcinogenic PAH. 5 refs., 1 fig.

  8. Transformation-associated recombination (TAR) cloning for genomics studies and synthetic biology.

    Science.gov (United States)

    Kouprina, Natalay; Larionov, Vladimir

    2016-09-01

    Transformation-associated recombination (TAR) cloning represents a unique tool for isolation and manipulation of large DNA molecules. The technique exploits a high level of homologous recombination in the yeast Sacharomyces cerevisiae. So far, TAR cloning is the only method available to selectively recover chromosomal segments up to 300 kb in length from complex and simple genomes. In addition, TAR cloning allows the assembly and cloning of entire microbe genomes up to several Mb as well as engineering of large metabolic pathways. In this review, we summarize applications of TAR cloning for functional/structural genomics and synthetic biology.

  9. Layers, Landslides, and Sand Dunes

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 27 October 2003This image shows the northern rim of one of the Valles Marineris canyons. Careful inspection shows many interesting features here. Note that the spurs and gullies in the canyon wall disappear some distance below the top of the canyon wall, indicating the presence of some smooth material here that weathers differently from the underlying rocks. On the floor of the canyon, there are remains from a landslide that came hurtling down the canyon wall between two spurs. Riding over the topography of the canyon floor are many large sand dunes, migrating generally from the lower right to upper left.Image information: VIS instrument. Latitude -14.1, Longitude 306.7 East (53.3 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. Backtrack modeling to locate the origin of tar balls depositing along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Ciappa, A.; Vethamony, P.

    . In the present study, the TBs that were deposited during May 2013 and May 2014 on the Goa coast were backtracked through a trajectory model, primarily to simulate their pathways and identify the reason for the occurrence of TBs only in May, and eventually...

  11. Laboratory singing sand avalanches.

    Science.gov (United States)

    Dagois-Bohy, Simon; Ngo, Sandrine; du Pont, Sylvain Courrech; Douady, Stéphane

    2010-02-01

    Some desert sand dunes have the peculiar ability to emit a loud sound up to 110 dB, with a well-defined frequency: this phenomenon, known since early travelers (Darwin, Marco Polo, etc.), has been called the song of dunes. But only in late 19th century scientific observations were made, showing three important characteristics of singing dunes: first, not all dunes sing, but all the singing dunes are composed of dry and well-sorted sand; second, this sound occurs spontaneously during avalanches on a slip face; third this is not the only way to produce sound with this sand. More recent field observations have shown that during avalanches, the sound frequency does not depend on the dune size or shape, but on the grain diameter only, and scales as the square root of g/d--with g the gravity and d the diameter of the grains--explaining why all the singing dunes in the same vicinity sing at the same frequency. We have been able to reproduce these singing avalanches in laboratory on a hard plate, which made possible to study them more accurately than on the field. Signals of accelerometers at the flowing surface of the avalanche are compared to signals of microphones placed above, and it evidences a very strong vibration of the flowing layer at the same frequency as on the field, responsible for the emission of sound. Moreover, other characteristics of the booming dunes are reproduced and analyzed, such as a threshold under which no sound is produced, or beats in the sound that appears when the flow is too large. Finally, the size of the coherence zones emitting sound has been measured and discussed.

  12. A terrestrial analog for transverse aeolian ridges (TARs): Environment, morphometry, and recent dynamics

    Science.gov (United States)

    Hugenholtz, Chris H.; Barchyn, Thomas E.

    2017-06-01

    Transverse aeolian ridges (TARs) are a distinct aeolian bedform found on Mars. The formative processes, evolution, and geological significance of TARs is poorly understood. Fundamentally, it is unknown whether TARs are dunes, mega-ripples, or another bedform type. We examined aeolian bedforms in the Lut Desert of Iran as a terrestrial analog for Martian TARs. From an objective sampling strategy with high-resolution satellite imagery, we developed a large morphometric dataset for comparison with existing Martian TARs. We also examined the dynamics of the Lut bedforms between 2004 and 2012 to determine if they were static or migrating. Results indicate that the range in the dimensions (length, width, height, and wavelength) of the Lut bedforms and Martian TARs overlap, suggesting Lut bedforms are a viable terrestrial TAR analog. Our sample yielded median values of 55.18 m, 9.80, 1.02 m, and 20 m for length (longest planview axis), width (shortest planview axis), height, and wavelength, respectively. Cumulative log-frequency plots of morphometric parameters suggest the sample is from a single population and process mechanism. Although the vast majority of Lut bedforms examined were static between 2004 and 2012, some migrated up to 0.09 myr-1 on average. This is much slower than nearby dunes (4-12 myr-1), but is explained by the existence of a surface lag of coarse particles on the TAR-like bedforms. The combination of morphometry, surface sedimentology, and slow migration rate indicate the Lut bedforms are mega-ripples, which provides evidence supporting interpretation of Martian TARs as mega-ripples. Testing the mega-ripple hypothesis for Martian TARs requires measurements of their sedimentology, which may be possible with the Mars Science Laboratory rover Curiosity, as well as expanded measurements of TAR morphometry to constrain their size, shape, and scaling.

  13. Effect of wastewater treatment processes on the pyrolysis properties of the pyrolysis tars from sewage sludges

    Science.gov (United States)

    Wu, Xia; Xie, Li-Ping; Li, Xin-Yu; Dai, Xiao-Hong; Fei, Xue-Ning; Jiang, Yuan-Guang

    2011-06-01

    The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 °C/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.

  14. Fortune Cookie Sand Dunes

    Science.gov (United States)

    2003-01-01

    MGS MOC Release No. MOC2-432, 25 July 2003This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small barchan sand dunes in the north polar region near 71.7oN, 51.3oW. Some of them are shaped like fortune cookies. The message these dunes provide: winds blow through this region from the lower right toward the upper left. The steep slip face slopes of these dunes, which point toward the upper left, indicate the wind direction. The scene is illuminated by sunlight from the upper right. The image is 3 km (1.9 mi) wide.

  15. 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.

  16. The extraction of bitumen from western oil sands. Annual report, July 1991--July 1992

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Acute toxicity of birch tar oil on aquatic organisms

    Directory of Open Access Journals (Sweden)

    M. HAGNER

    2008-12-01

    Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

  18. Quantitative group-type analysis of coal-tar pitches

    Energy Technology Data Exchange (ETDEWEB)

    Membrado, L.; Cebolla, V.L.; Vela, J. [Instituto de carboquimica, Zaragoza (Spain)

    1995-12-31

    Preparative liquid chromatographic (LC) and related techniques (e.g.., extrography) are mostly used for quantitative compound class or group-type analysis of coal-tar pitches. TLC-FID has hardly been used for this purpose because of the time-consuming calibration steps required. As the FID response of each peak depends on its nature, the classical approach in fossil fuel analysis to a quantitative analysis is the absolute calibration using fractions derived from the fossil fuel itself (previously isolated by LC) as external standards. An added problem is the isolation of these fractions with the required purity. A TLC-FID system has previously been described in this issue, which gives adequate repeatability and precision, and gives a quantitative FID response. In this work, a rapid calibration procedure which allows a quantitative group-type analysis of a whole coal-tar pitch (without any prefractionation) using TLC-FID is presented as an alternative to absolute calibration. This method considerably reduces the total time of analysis. Likewise, the use of TLC-FID as a monitoring technique to improve the classical absolute calibration is also proposed. Pros and cons of group-type analysis techniques are finally discussed with regard to TLC-FID.

  19. A baseline assessment of beach debris and tar contamination in Bonaire, Southeastern Caribbean

    NARCIS (Netherlands)

    Debrot, A.O.; Rijn, van J.; Bron, P.S.; Leon, R.

    2013-01-01

    Data on beach debris and tar contamination is provided for 21 natural beach sites in Bonaire, Southeastern Caribbean. Transects amounting to a combined length of 991 m were sampled March–May 2011 and a total of 8960 debris items were collected. Highest debris and tar contamination were found on the

  20. Relationship Between the Composition and Interfacial Tension of Former Manufactured Gas Plant Tars

    Science.gov (United States)

    Hauswirth, S.; Birak, P. S.; Miller, C. T.

    2011-12-01

    Former manufactured gas plant (FMGP) tars pose significant environmental hazards and present a challenge to regulators and industry professionals. The tars, which were produced as a byproduct of the gas manufacturing process, were frequently released into the environment through improper disposal or leaks in plant infrastructure. The interfacial tension (IFT) is a primary factor controlling the mobility of tars in porous media, and is therefore important to understand for both predicting the migration of tars and designing remediation strategies. In this study, we characterized nine field-collected FMGP tars and a commercially available coal tar by means of chemical extractions (asphaltenes, resins, acids, and bases), gas chromatography-mass spectrometry (GC-MS), and Fourier transform infrared (FTIR) spectroscopy. Additionally, the IFT and contact angle of each tar was determined for a pH range of 3-11. The IFT was found to be similar for all tars at pH 5 and 7 regardless of composition. Slight decreases in IFT at lower pH were correlated with higher concentrations of extractable bases, which consisted primarily of nitrogen-containing heterocyclic aromatic compounds. Much greater reductions of IFT were observed at high pH. These reductions were found to be associated with the presence of carbonyl or carboxyl groups in the asphaltenes. It is likely that the larger size of the asphaltene molecules (as compared to the extractable compounds) resulted in species with greater surface activity when ionized.

  1. No increased risk of cancer after coal tar treatment in patients with psoriasis or eczema.

    NARCIS (Netherlands)

    Roelofzen, J.H.J.; Aben, K.K.H.; Oldenhof, U.T.H.; Coenraads, P.J.; Alkemade, J.A.C.; Kerkhof, P.C.M. van de; Valk, P.G.M. van der; Kiemeney, L.A.L.M.

    2010-01-01

    Coal tar is an effective treatment for psoriasis and eczema, but it contains several carcinogenic compounds. Occupational and animal studies have shown an increased risk of cancer after exposure to coal tar. Many dermatologists have abandoned this treatment for safety reasons, although the risk of

  2. No Increased Risk of Cancer after Coal Tar Treatment in Patients with Psoriasis or Eczema

    NARCIS (Netherlands)

    Roelofzen, Judith H. J.; Aben, Katja K. H.; Oldenhof, Ursula T. H.; Coenraads, Pieter-Jan; Alkemade, Hans A.; van de Kerkhof, Peter C. M.; van der Valk, Pieter G. M.; Kiemeney, Lambertus A. L. M.

    Coal tar is an effective treatment for psoriasis and eczema, but it contains several carcinogenic compounds. Occupational and animal studies have shown an increased risk of cancer after exposure to coal tar. Many dermatologists have abandoned this treatment for safety reasons, although the risk of

  3. Biomass Gasifier ''Tars'': Their Nature, Formation, and Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Milne, T. A.; Evans, R. J. (National Renewable Energy Laboratory); Abatzaglou, N. (Kemestrie, Inc.)

    1998-11-01

    The main purpose of this review is to update the information on gasification tar, the most cumbersome and problematic parameter in any gasification commercialization effort. The work aims to present to the community the scientific and practical aspects of tar formation and conversion (removal) during gasification as a function of the various technological and technical parameters and variables.

  4. The Legend of Hot Tar or Pitch as a Defensive Weapon

    DEFF Research Database (Denmark)

    Atzbach, Rainer

    2015-01-01

    production and use during the Middle Ages will be discussed with special focus on the application of tar pitch as an ingredient in medieval and post-medieval thermal weapons (especially Greek Fire, the firebomb and the fire arrow). The punishment of tarring and feathering will also be considered...

  5. Dissolution and transport of coal tar compounds in fractured clay-rich residuum

    DEFF Research Database (Denmark)

    Vulava, Vijay M.; McKay, Larry D.; Broholm, Mette Martina

    2012-01-01

    We investigated the dissolution and transport of organic contaminants from a crude coal tar mixture in a monolith of fractured clay-rich residuum. An electrolyte solution was eluted through the residuum monolith containing a small emplaced source of coal tar under biologically inhibited and mildly...

  6. 21 CFR 740.18 - Coal tar hair dyes posing a risk of cancer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Coal tar hair dyes posing a risk of cancer. 740.18 Section 740.18 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.18 Coal tar hair dyes...

  7. Cigarette tar content and symptoms of chronic bronchitis: results of the Scottish Heart Health Study.

    Science.gov (United States)

    Brown, C A; Crombie, I K; Smith, W C; Tunstall-Pedoe, H

    1991-12-01

    The aim was to determine if there was a relationship between cigarette tar yield and rates of chronic cough and chronic phlegm. 22 districts across Scotland were used for the Scottish Heart Health Study (SHHS) which was conducted between 1984 and 1986 and from which the data for this analysis were obtained. 10,359 men and women aged 40-59 years were studied. Of these, 2801 current cigarette smokers whose brand of cigarette smoked was known were selected. Data on self reported smoking habits and prevalence of chronic cough and chronic phlegm were obtained from the SHHS. Tar yield was divided into three groups: low (less than or equal to 12 mg/cigarette); middle (13-14 mg/cigarette); high (greater than or equal to 15 mg/cigarette). The average tar yield consumed per person was 13.2 mg/cigarette. Women in the middle and high tar groups had smoked for longer and had significantly higher breath carbon monoxide levels, serum thiocyanate levels, serum cotinine levels, and daily cigarette consumption than the women in the low tar group. This pattern was not seen in men for any of these five smoking variables. Rates of chronic cough and chronic phlegm were higher with higher tar yield of cigarettes smoked for women (low tar v high tar: p less than 0.001) but not for men. Daily cigarette consumption and the number of years of smoking were the most significant risk factors for chronic cough and chronic phlegm for both men and women. Tar was still a significant risk factor (p less than 0.05) for women after controlling for these two risk factors and social class. Both sexes show strong effects of daily cigarette consumption and years of smoking on respiratory symptoms; women show an additional effect of cigarette tar content while men do not. The spread of tar yield in both sexes was small but there were more women on low tar cigarettes and this may have enabled a weak effect of tar to be seen better in them. On the other hand, tar level in women was confounded with other

  8. Influence of Pyrolysis Temperature on Rice Husk Char Characteristics and Its Tar Adsorption Capability

    Directory of Open Access Journals (Sweden)

    Anchan Paethanom

    2012-11-01

    Full Text Available A biomass waste, rice husk, was inspected by thermoanalytical investigation to evaluate its capability as an adsorbent medium for tar removal. The pyrolysis process has been applied to the rice husk material at different temperatures 600, 800 and 1000 °C with 20 °C/min heating rate, to investigate two topics: (1 influence of temperature on characterization of rice husk char and; (2 adsorption capability of rice husk char for tar removal. The results showed that subsequent to high temperature pyrolysis, rice husk char became a highly porous material, which was suitable as tar removal adsorbent with the ability to remove tar effectively. In addition, char characteristics and tar removal ability were significantly influenced by the pyrolysis temperature.

  9. Task 3.9 -- Catalytic tar cracking. Semi-annual report, January 1--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Young, B.C.; Timpe, R.C.

    1995-12-31

    Tar produced in the gasification of coal is deleterious to the operation of downstream equipment including fuel cells, gas turbines, hot-gas stream cleanup filters, and pressure swing adsorption systems. Catalytic cracking of tars to smaller hydrocarbons can be an effective means to remove these tars from gas streams and, in the process, generate useful products, e.g., methane gas, which is crucial to the operation of molten carbonate fuel cells. The objectives of this project are to investigate whether gasification tars can be cracked by synthetic nickel-substituted micamontmorillonite, zeolite, or dolomite material; and whether the tars can be cracked selectively by these catalysts to produce a desired liquid and/or gas stream. Results to date are presented in the cited papers.

  10. Uluslararası ticari boyutuyla organik tarım ve devlet destekleri

    OpenAIRE

    İpek, Selçuk; Çil, Gözde Yaşar

    2010-01-01

    Küresel düzeyde yaşanan çevre kirliliği ve buna bağlı olarak doğal dengenin korunması ihtiyacı, beraberinde bazı alternatif üretim şekillerini de gündeme getirmiştir. Bu üretim şekillerinin tarımsal alana yansıması organik tarım şeklinde olmuştur. Toplumlarda çevre ve sağlığa ilişkin bilinç düzeyiyle birlikte organik tarıma ilgi artmakta ve dünyada organik tarım pazarı artan oranlarda genişlemektedir. Organik tarım açısından gelişmiş ülkeler kendi iç taleplerini ka...

  11. 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...

  12. 2010 oil sands performance report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    With the depletion of traditional energy resources and the rising demand for energy, oil sands have become an important energy resource for meeting energy needs. Oil sands are a mixture of water, sand, clay and bitumen which is recovered either through open pit mining or in situ drilling techniques. The bitumen is then converted into syncrude or sold to refineries for the production of gasoline, diesel or other products. Shell has oil sands operations in Alberta and the aim of this report is to present its 2010 performance in terms of CO2, water, tailings, land, and reclamation and engagement. This document covers several of Shell's operations in the Muskeg River and Jackpine mines, Scotford upgrader, Peace River, Orion, Seal, Cliffdale and Chipmunk. It provides useful information on Shell's oil sands performance to governments, environmental groups, First Nations, local communities and the public.

  13. Kinetics of mesophase transformation of coal tar pitch

    Energy Technology Data Exchange (ETDEWEB)

    Shui, H.; Feng, Y.; Shen, B.; Gao, J. [East China Institute of Metallurgy, Maanshan (China)

    1998-05-01

    A study on the kinetics of mesophase transformation of two coal tar pitches (CTP) with different primary quinoline-insoluble (QI) content is reported. It showed that the meosphase transformation of CTP studied was an autocatalytic type reaction. The rate law and rate constants for the mesophase transformation at holding temperature of 390{degree}C, 410{degree}C and 450{degree}C were determined and the rate constants of mesophase transformation follow the Arrhenius equation. Primary QI of CTP decreases the activation energy from 210.1 kJ/mol to 175.8 kJ/mol, and the pre-exponential factor from 2.12 x 10{sup 13} 1/h to 6.29 x 10{sup 10} 1/h; its influence on the rate constants is irregular. 8 refs., 3 figs., 3 tabs.

  14. DETERMINATION OF WATER CONTENT IN PYROLYTIC TARS USING COULOMETRIC KARL-FISHER TITRATION

    Directory of Open Access Journals (Sweden)

    Lenka Jílková

    2017-02-01

    Full Text Available The liquid organic fraction of pyrolytic tar has a high energy value which makes possible its utilization as an energy source. However, before utilization, it is crucial to remove water from the liquid fraction. The presence of water reduces the energy value of pyrolytic tars. Water separation from the organic tar fraction is a complex process, since an emulsion can be readily formed. Therefore, after phase separation, it is important to know the residual water content in the organic phase and whether it is necessary to further dry it. The results presented in this manuscript focus on a water determination in liquid products from coal and biomass pyrolysis by a coulometric Karl‑Fischer titration. The Coulometric Karl‑Fischer titration is often used for a water content determination in gaseous, liquid and solid samples. However, to date, this titration method has not been used for a water determination in tars. A new water determination method, which has been tested on different types of tar, has been developed. The Coulometric Karl‑Fischer titration is suitable for tar samples with a water content not greater than 5 wt. %. The obtained experimental results indicate that the new introduced method can be used with a very good repeatability for a water content determination in tars.

  15. Catalytic Tar Reduction for Assistance in Thermal Conversion of Space Waste for Energy Production

    Science.gov (United States)

    Caraccio, Anne Joan; Devor, Robert William; Hintze, Paul E.; Muscatello, Anthony C.; Nur, Mononita

    2014-01-01

    The Trash to Gas (TtG) project investigates technologies for converting waste generated during spaceflight into various resources. One of these technologies was gasification, which employed a downdraft reactor designed and manufactured at NASA's Kennedy Space Center (KSC) for the conversion of simulated space trash to carbon dioxide. The carbon dioxide would then be converted to methane for propulsion and water for life support systems. A minor byproduct of gasification includes large hydrocarbons, also known as tars. Tars are unwanted byproducts that add contamination to the product stream, clog the reactor and cause complications in analysis instrumentation. The objective of this research was to perform reduction studies of a mock tar using select catalysts and choose the most effective for primary treatment within the KSC downdraft gasification reactor. Because the KSC reactor is operated at temperatures below typical gasification reactors, this study evaluates catalyst performance below recommended catalytic operating temperatures. The tar reduction experimentation was observed by passing a model tar vapor stream over the catalysts at similar conditions to that of the KSC reactor. Reduction in tar was determined using gas chromatography. Tar reduction efficiency and catalyst performances were evaluated at different temperatures.

  16. Sampling of benzene in tar matrices from biomass gasification using two different solid-phase sorbents.

    Science.gov (United States)

    Osipovs, Sergejs

    2008-06-01

    Biomass tar mainly consists of stable aromatic compounds such as benzene and polyaromatic hydrocarbons, benzene being the biggest tar component in real biomass gasification gas. For the analysis of individual tar compounds, the solid-phase adsorption method was chosen. According to this method, tar samples are collected on a column with an amino-phase sorbent. With a high benzene concentration in biomass tar, some of the benzene will not be collected on the amino-phase sorbent. To get over this situation, we have installed another column with activated charcoal which is intended for collection of volatile organic compounds, including benzene, after the column with the amino-phase sorbent. The study of maximal adsorption amounts of various compounds on both adsorbents while testing different sampling volumes led to the conclusion that benzene is a limiting compound. The research proved that the use of two sorbents (500 mg + 100 mg) connected in series allows for assessment of tar in synthesis gas with a tar concentration up to 30-40 g m(-3), which corresponds to the requirements of most gasifiers.

  17. Understanding the stability of pyrolysis tars from biomass in a view point of free radicals.

    Science.gov (United States)

    He, Wenjing; Liu, Qingya; Shi, Lei; Liu, Zhenyu; Ci, Donghui; Lievens, Caroline; Guo, Xiaofen; Liu, Muxin

    2014-03-01

    Fast pyrolysis of biomass has attracted increasing attention worldwide to produce bio-tars that can be upgraded into liquid fuels and chemicals. However, the bio-tars are usually poor in quality and stability and are difficult to be upgraded. To better understand the nature of the bio-tars, this work reveals radical concentration of tars derived from pyrolysis of two kinds of biomass. The tars were obtained by condensing the pyrolysis volatiles in 3s. It shows that the tars contain large amounts of radicals, at a level of 10(16)spins/g, and are able to generate more radicals at temperatures of 573K or higher, reaching a level of 10(19)spins/g at 673K in less than 30min. The radical generation in the tar samples is attributed to the formation of THF insoluble matters (coke), which also contain radicals. The radical concentrations of the aqueous liquids obtained in pyrolysis are also studied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Opening of the TAR hairpin in the HIV-1 genome causes aberrant RNA dimerization and packaging

    Directory of Open Access Journals (Sweden)

    Das Atze T

    2012-07-01

    Full Text Available Abstract Background The TAR hairpin is present at both the 5′ and 3′ end of the HIV-1 RNA genome. The 5′ element binds the viral Tat protein and is essential for Tat-mediated activation of transcription. We recently observed that complete TAR deletion is allowed in the context of an HIV-1 variant that does not depend on this Tat-TAR axis for transcription. Mutations that open the 5′ stem-loop structure did however affect the leader RNA conformation and resulted in a severe replication defect. In this study, we set out to analyze which step of the HIV-1 replication cycle is affected by this conformational change of the leader RNA. Results We demonstrate that opening the 5′ TAR structure through a deletion in either side of the stem region caused aberrant dimerization and reduced packaging of the unspliced viral RNA genome. In contrast, truncation of the TAR hairpin through deletions in both sides of the stem did not affect RNA dimer formation and packaging. Conclusions These results demonstrate that, although the TAR hairpin is not essential for RNA dimerization and packaging, mutations in TAR can significantly affect these processes through misfolding of the relevant RNA signals.

  19. Processing of bituminous coal tar at high temperature with bituminous coal additive

    Energy Technology Data Exchange (ETDEWEB)

    von Hartmann, G.B.; Hupfer, H.; Leonhardt, P.

    1943-05-10

    In short tests, results of the effects of a bituminous coal addition to the processing of tar and pitch were obtainable. Coal used was that from the Heinitz Mines (Upper Silesian), saturated with 1--1.2% iron sulphate. On a mixture of bituminous coal tar residue and tar oil, with a relatively low level of solids and asphalt, a substitution was made for the addition of 2% alkalized iron-grude-catalyst with 20% coal. The same yield was reached using a straight-run procedure. The coal gave somewhat more gasification and additional asphalt in the sludge without increasing the solids content correspondingly. In spite of this, the carbonization results were somewhat improved, which led one to conclude that the coal addition fostered the decomposition of the tar asphalt, and, that the asphalt from the coal could be better carbonized than that out of the tar. One found, also, that the tar mixture with coal additive permitted trouble-free hydrogenation to gasoline and middle oil. Still another short test met with success. A bituminous coal tar pitch containing 24% benzene solids and 36% asphalt, which could not be processed with iron catalyst or even molybdenum-grude, was hydrogenated to gasoline and middle oil with a usable yield of .25 by a 20--25% addition of coal. Here too, the carbonization results were good. The addition of coal had no notable influence on the properties of the resulting oils. The document included test procedures. 11 tables.

  20. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle [Emory University School of Medicine, Atlanta, GA (United States). Department of Dermatology

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  1. Spectroscopic characterization of a Nigerian standard sand: Igbokoda sand

    CSIR Research Space (South Africa)

    Ojuri, OO

    2017-01-01

    Full Text Available the Middle Ordovician St. Peter Sandstone near Ottawa, Illinois, had been picked by the American Society for Testing and Materials (ASTM) as the reference sand to employ in testing cement and strength of concrete [9]. To the best of our knowledge... and magnetic resonance spectroscopic techniques due to its importance in cement, geotechnical/geo-environmental research in Nigeria. This should halt importation of standard silica sand for mortar and concrete testing...

  2. A comparison of thermal conversion process for several coal tar pitches

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Y.; Shui, H.; Yuan, X. [East China Metallurgical Institute, Ma`anshan (China)

    1995-03-01

    The property and constituents of coal tar pitch are of great importance to the production of raw material for needle coke. Structural constituents of five coal tar pitches were determined using {sup 1}H-NMR. Besides, thermal conversion process of these pitches in which primary quinoline in soluble fraction was removed by centrifugal separation method was also investigated. The experimental results show Baogang (I) and Meishan coal tar pitches meet the requirements of raw material for needle coke. The thermal conversion data was correlated with structural parameters. 6 refs.,1 fig., 1 tab.

  3. GC/MS analysis of coal tar composition produced from coal pyrolysis

    Directory of Open Access Journals (Sweden)

    Jianfang Jiang

    2007-08-01

    Full Text Available Coal tar is a significant product generated from coal pyrolysis. A detailed analytical study on its composition and chemical structure will be of great advantage to its further processing and utilization. Using a combined method of planigraphy-gas chromatograph/mass spectroscopy (GC/MS, this work presents a composition analysis on the coal tar generated in the experiment. The analysis gives a satisfactory result, which offers a referable theoretical foundation for the further processing and utilization of coal tar.

  4. Pyrolysis products from different biomasses: application to the thermal cracking of tar

    Energy Technology Data Exchange (ETDEWEB)

    Fagbemi, L.; Khezami, L.; Capart, R. [Universite de Technologie de Compiegne, Dept. de Genie Chimique, Compiegne, 60 (France)

    2001-08-01

    The purpose of this study was to evaluate the amounts of various pyrolysis products (gases, water, tar and charcoal) from three biomasses (wood, coconut shell and straw) and to suggest a kinetic equation for the thermal cracking of tar at temperatures varying from 400 to 900 deg C. From the results, a comparative analysis is done for the biomasses, and a kinetic model of thermal cracking of tar is proposed for a residence time ranging from zero to 4s. This can be applied to the purification of gasification gases used as a feed gas to a combustion engine, and so contributes to the design of gasifiers. (Author)

  5. 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...... occurring in various glacial environments. This study specifically focuses on the appearance and spatial distribution of sand lenses in tills. It introduces a methodology on how to measure and characterize sand lenses in the field with regard to size, shape and degree of deformation. A set of geometric...... parameters is defined to allow characterization of sand lenses. The proposed classification scheme uses a stringent terminology to distinguish several types of sand lenses based on the geometry. It includes sand layers, sand sheets, sand bodies, sand pockets and sand stringers. The methodology has been...

  6. Geologic map of Great Sand Dunes National Park, Colorado

    Science.gov (United States)

    Madole, Richard F.; VanSistine, D. Paco; Romig, Joseph H.

    2016-10-20

    Geologic mapping was begun after a range fire swept the area of what is now the Great Sand Dunes National Park in April 2000. The park spans an area of 437 square kilometers (or about 169 square miles), of which 98 percent is blanketed by sediment of Quaternary age, the Holocene and Pleistocene Epochs; hence, this geologic map of the Great Sand Dunes National Park is essentially a surficial geologic map. These surficial deposits are diverse and include sediment of eolian (windblown), alluvial (stream and sheetwash), palustrine (wetlands and marshes), lacustrine (lake), and mass-wasting (landslides) origin. Sediment of middle and late Holocene age, from about 8,000 years ago to the present, covers about 80 percent of the park.Fluctuations in groundwater level during Holocene time caused wetlands on the nearby lowland that bounds the park on the west to alternately expand and contract. These fluctuations controlled the stability or instability of eolian sand deposits on the downwind (eastern) side of the lowland. When groundwater level rose, playas became lakes, and wet or marshy areas formed in many places. When the water table rose, spring-fed streams filled their channels and valley floors with sediment. Conversely, when groundwater level fell, spring-fed streams incised their valley floors, and lakes, ponds, and marshes dried up and became sources of windblown sand.Discharge in streams draining the west flank of the Sangre de Cristo Range is controlled primarily by snowmelt and flow is perennial until it reaches the mountain front, beyond which streams begin losing water at a high rate as the water soaks into the creek beds. Even streams originating in the larger drainage basins, such as Sand and Medano Creeks, generally do not extend much more than 4 km (about 2.5 miles) beyond where they exit the mountains.The Great Sand Dunes contain the tallest dunes (maximum height about 750 feet, or 230 m) in North America. These dunes cover an area of 72 square kilometers

  7. 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.

  8. Management recommendations: Sand Lake Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a review of land management practices at the Sand Lake National Wildlife Refuge, by a land use specialist. Recommendations, time frame and...

  9. Oakland, West

    OpenAIRE

    Kwamille, Tasion Shawniece

    2013-01-01

    “Oakland, West” Produced by: Tasion Kwamilele          After World War II, many blacks from the south migrated to Oakland to work in the shipyards; housing discrimination forced blacks to move to West Oakland. But when those jobs died out many Blacks moved from West Oakland and the area became deserted and filled with crime, drugs, violence, and poverty.         The 7.0 Loma Prueta Earthquake, also known as the World Series Quake of 1989, shook the Bay Are...

  10. Sensuous Communism: Sand with Marx

    OpenAIRE

    White, Claire

    2015-01-01

    This article reads George Sand's Le Compagnon du Tour de France (1840) alongside Karl Marx's “Economic and Philosophic Manuscripts of 1844.” It considers how these contemporaries bring to bear on their accounts of labor, estrangement, and the structures of property an attention to the fate of the senses under capitalism. Both elaborate a critique of political economy—Sand's voiced by her worker-hero—that demonstrates how the individual's sensuous life is circumscribed by the pressures of mate...

  11. Secondary reactions of tar during thermochemical biomass conversion[Dissertation 14341

    Energy Technology Data Exchange (ETDEWEB)

    Morf, P.O.

    2001-07-01

    This dissertation submitted to the Swiss Federal Institute of Technology in Zurich presents and discusses the results obtained during the examination of the processes involved in the formation and conversion of tar in biomass gasification plant. Details are given on the laboratory reactor system used to provide separated tar production and conversion for the purposes of the experiments carried out. The results of analyses made of the tar and the gaseous products obtained after its conversion at various temperatures are presented. The development of kinetic models using the results of the experiments that were carried out is described. The results of the experiments and modelling are compared with the corresponding results obtained using a full-scale down-draft, fixed-bed gasifier. The author is of the opinion that the reaction conditions found in full-scale gasifiers can be well simulated using heterogeneous tar conversion experiments using the lab reactor system.

  12. Dermatological exposure to coal tar and bladder cancer risk: a case-control study

    NARCIS (Netherlands)

    Roelofzen, J.H.; Aben, K.K.H.; Kerkhof, P.C.M. van de; Valk, P.G. van der; Kiemeney, L.A.L.M.

    2015-01-01

    OBJECTIVE: Coal tar ointments are used as treatment of various skin diseases, especially psoriasis and eczema. These ointments contain several carcinogenic polycyclic aromatic hydrocarbons. Metabolites of these polycyclic aromatic hydrocarbons are excreted in the urine and therefore, dermatological

  13. Effects of Syngas Cooling and Biomass Filter Medium on Tar Removal

    Directory of Open Access Journals (Sweden)

    Sunil Thapa

    2017-03-01

    Full Text Available Biomass gasification is a proven technology; however, one of the major obstacles in using product syngas for electric power generation and biofuels is the removal of tar. The purpose of this research was to develop and evaluate effectiveness of tar removal methods by cooling the syngas and using wood shavings as filtering media. The performance of the wood shavings filter equipped with an oil bubbler and heat exchanger as cooling systems was tested using tar-laden syngas generated from a 20-kW downdraft gasifier. The tar reduction efficiencies of wood shavings filter, wood shavings filter with heat exchanger, and wood shavings filter with oil bubbler were 10%, 61%, and 97%, respectively.

  14. Study of catalytic upgrading of biomass tars using Indonesian iron ore

    Science.gov (United States)

    Wicakso, Doni Rahmat; Sutijan, Rochmadi, Budiman, Arief

    2017-03-01

    Catalytic decomposition is a promising way for chemical upgrading process of low quality oil such as biomass tars. In this experiment, catalytic decomposition of biomass tars was performed over Indonesian low grade iron ore catalyst. This process is carried out in a fixed bedreactor which is equipped with preheater to convert the tars into vapor form. The reaction was studied at the temperature range of 500 - 700°C. The kinetic study of catalytic decomposition of biomass tars is represented using first order reaction. The results show that value of constant of chemical reaction is in range 0.2514 - 0.9642 cm3.gr-1.min-1 with value of the frequency factor (A) and the activation energy (E) are 48.98 min-1 and 5724.94 cal.mol-1, respectively.

  15. Thatcheri tütar avalikustas Raudse Leedi nõdrameelsuse / Sandra Maasalu

    Index Scriptorium Estoniae

    Maasalu, Sandra

    2008-01-01

    Ilmunud ka: Postimees : na russkom jazõke 26. aug. 2008, lk. 9. Suurbritannia endise peaministri Margaret Thatcheri tütar Carol Thatcher kirjutab peatselt ilmuvas mälestusteraamatus oma ema dementsusest

  16. Review of the Literature on Catalytic Biomass Tar Destruction: Milestone Completion Report

    Energy Technology Data Exchange (ETDEWEB)

    Dayton, D.

    2002-12-01

    A summary of literature pertaining to catalytic biomass gasification''tar'' destruction, an overview of catalysts studied, and an evaluation of the future potential for this gas cleaning technology.

  17. Upgrading producer gas quality from rubber wood gasification in a radio frequency tar thermocatalytic treatment reactor.

    Science.gov (United States)

    Anis, Samsudin; Zainal, Z A

    2013-12-01

    This study focused on improving the producer gas quality using radio frequency (RF) tar thermocatalytic treatment reactor. The producer gas containing tar, particles and water was directly passed at a particular flow rate into the RF reactor at various temperatures for catalytic and thermal treatments. Thermal treatment generates higher heating value of 5.76 MJ Nm(-3) at 1200°C. Catalytic treatments using both dolomite and Y-zeolite provide high tar and particles conversion efficiencies of about 97% on average. The result also showed that light poly-aromatic hydrocarbons especially naphthalene and aromatic compounds particularly benzene and toluene were still found even at higher reaction temperatures. Low energy intensive RF tar thermocatalytic treatment was found to be effective for upgrading the producer gas quality to meet the end user requirements and increasing its energy content. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Light absorption properties of laboratory generated tar ball particles

    Science.gov (United States)

    Hoffer, A.; Tóth, A.; Nyirő-Kósa, I.; Pósfai, M.; Gelencsér, A.

    2015-06-01

    Tar balls (TBs) are a specific particle type which is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC) which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g. organic particles with inorganic inclusions and soot, the latter is emitted mainly during flaming conditions) from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study we have installed on-line instruments to our laboratory set-up generating pure TB particles to measure the absorption and scattering, as well as size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM) and total carbon (TC) analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory generated TBs were found to be in the range of 0.8-3.0 m2 g-1 at 550 nm, with absorption Ångström exponents (AAE) between 2.7 and 3.4 (average 2.9) in the wavelength range 467-652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84-0.21i at 550 nm. In the brown carbon continuum these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS). Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning emissions, these findings may have substantial

  19. Light absorption properties of laboratory-generated tar ball particles

    Directory of Open Access Journals (Sweden)

    A. Hoffer

    2016-01-01

    Full Text Available Tar balls (TBs are a specific particle type that is abundant in the global troposphere, in particular in biomass smoke plumes. These particles belong to the family of atmospheric brown carbon (BrC, which can absorb light in the visible range of the solar spectrum. Albeit TBs are typically present as individual particles in biomass smoke plumes, their absorption properties have been only indirectly inferred from field observations or calculations based on their electron energy-loss spectra. This is because in biomass smoke TBs coexist with various other particle types (e.g., organic particles with inorganic inclusions and soot, the latter emitted mainly during flaming conditions from which they cannot be physically separated; thus, a direct experimental determination of their absorption properties is not feasible. Very recently we have demonstrated that TBs can be generated in the laboratory from droplets of wood tar that resemble atmospheric TBs in all of their observed properties. As a follow-up study, we have installed on-line instruments to our laboratory set-up, which generate pure TB particles to measure the absorption and scattering, as well as the size distribution of the particles. In addition, samples were collected for transmission electron microscopy (TEM and total carbon (TC analysis. The effects of experimental parameters were also studied. The mass absorption coefficients of the laboratory-generated TBs were found to be in the range of 0.8–3.0 m2 g−1 at 550 nm, with absorption Ångström exponents (AAE between 2.7 and 3.4 (average 2.9 in the wavelength range 467–652 nm. The refractive index of TBs as derived from Mie calculations was about 1.84 − 0.21i at 550 nm. In the brown carbon continuum, these values fall closer to those of soot than to other light-absorbing species such as humic-like substances (HULIS. Considering the abundance of TBs in biomass smoke and the global magnitude of biomass burning

  20. Selected constituents in the smokes of foreign commercial cigaretts: tar, nicotine, carbon monoxide, and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    The tar, nicotine, carbon monoxide, and carbon dioxide contents of the smokes of 220 brands of foreign commercial cigarettes are reported. In some instances, filter cigarettes of certain brands were found to deliver as much or more smoke constituents than their nonfilter counterparts. Also, data indicated that there can be a great variation in the tar, nicotine, or carbon monoxide content of the smoke of samples of a given brand of cigarettes, depending on the nation in which they are purchased. 24 tables.

  1. Integrated Biomass Gasification with Catalytic Partial Oxidation for Selective Tar Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lingzhi; Wei, Wei; Manke, Jeff; Vazquez, Arturo; Thompson, Jeff; Thompson, Mark

    2011-05-28

    Biomass gasification is a flexible and efficient way of utilizing widely available domestic renewable resources. Syngas from biomass has the potential for biofuels production, which will enhance energy security and environmental benefits. Additionally, with the successful development of low Btu fuel engines (e.g. GE Jenbacher engines), syngas from biomass can be efficiently used for power/heat co-generation. However, biomass gasification has not been widely commercialized because of a number of technical/economic issues related to gasifier design and syngas cleanup. Biomass gasification, due to its scale limitation, cannot afford to use pure oxygen as the gasification agent that used in coal gasification. Because, it uses air instead of oxygen, the biomass gasification temperature is much lower than well-understood coal gasification. The low temperature leads to a lot of tar formation and the tar can gum up the downstream equipment. Thus, the biomass gasification tar removal is a critical technology challenge for all types of biomass gasifiers. This USDA/DOE funded program (award number: DE-FG36-O8GO18085) aims to develop an advanced catalytic tar conversion system that can economically and efficiently convert tar into useful light gases (such as syngas) for downstream fuel synthesis or power generation. This program has been executed by GE Global Research in Irvine, CA, in collaboration with Professor Lanny Schmidt's group at the University of Minnesota (UoMn). Biomass gasification produces a raw syngas stream containing H2, CO, CO2, H2O, CH4 and other hydrocarbons, tars, char, and ash. Tars are defined as organic compounds that are condensable at room temperature and are assumed to be largely aromatic. Downstream units in biomass gasification such as gas engine, turbine or fuel synthesis reactors require stringent control in syngas quality, especially tar content to avoid plugging (gum) of downstream equipment. Tar- and ash-free syngas streams are a critical

  2. Criteria for selection of dolomites and catalysts for tar elimination from biomass gasification gas. Kinetic constants

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1996-12-31

    Calcined dolomites and commercial steam reforming catalysts are used downstream biomass gasifiers for hot catalytic raw gas cleaning. To further compare these solids under a rigorous basis, a reaction network and a kinetic model are presented. The apparent kinetic constant for the tar reduction is here proposed as a basis of comparison. Tar sampling and analysis, and the units used for the space-time in the catalytic reactor affect the kinetic constants observed. (author) (2 refs.)

  3. Gasification of municipal solid waste in a downdraft gasifier: Analysis of tar formation

    Directory of Open Access Journals (Sweden)

    Tabitha Geoffrey Etutu

    2016-04-01

    Full Text Available In this study, municipal solid waste (MSW from a dumpsite was converted into refuse derived fuel (RDF and used as feedstock for an air-blown gasification process. The gasification process was conducted in a 10 kg.hr -1 downdraft gasifier at different air flow rates of 300, 350, 400, 450 and 550 NL.min1 at atmospheric pressure in order to investigate the quantity and quality of tar formed. It was shown that the increase in the air flow rate from 300 NL.min1 to 550 NL.min1 led to an increase in the oxidation temperature from 719°C to 870°C and an increase in the reduction temperature from 585°C to 750°C, respectively. Tar was reduced from 15 g.Nm3 to 4.7 g.Nm3 respectively. Heavy tar compounds (>C17 e.g. pyrene and phenathrene, decreased with the increase in the light tar compounds (tar reduction through a tar cracking process.

  4. Impact of genetic variants on haematopoiesis in patients with thrombocytopenia absent radii (TAR) syndrome.

    Science.gov (United States)

    Manukjan, Georgi; Bösing, Hendrik; Schmugge, Markus; Strauß, Gabriele; Schulze, Harald

    2017-11-01

    Thrombocytopenia absent radii (TAR) syndrome is clearly defined by the combination of radial aplasia and reduced platelet counts. The genetics of TAR syndrome has recently been resolved and comprises a microdeletion on Chromosome 1 including the RBM8A gene and a single nucleotide polymorphism (SNP) either at the 5' untranslated region (5'UTR) or within the first intron of RBM8A. Although phenotypically readily diagnosed after birth, the genetic determination of particular SNPs in TAR syndrome harbours valuable information to evaluate disease severity and treatment decisions. Here, we present clinical data in a cohort of 38 patients and observed that platelet counts in individuals with 5'UTR SNP are significantly lower compared to patients bearing the SNP in intron 1. Moreover, elevated haemoglobin values could only be assessed in patients with 5'UTR SNP whereas white blood cell count is unaffected, indicating that frequently observed anaemia in TAR patients could also be SNP-dependent whereas leucocytosis does not correlate with genetic background. However, this report on a large cohort provides an overview of important haematological characteristics in TAR patients, facilitating evaluation of the various traits in this disease and indicating the importance of genetic validation for TAR syndrome. © 2017 John Wiley & Sons Ltd.

  5. Dissolution and transport of coal tar compounds in fractured clay-rich residuum.

    Science.gov (United States)

    Vulava, Vijay M; McKay, Larry D; Broholm, Mette M; McCarthy, John F; Driese, Steven G; Sayler, Gary S

    2012-02-15

    We investigated the dissolution and transport of organic contaminants from a crude coal tar mixture in a monolith of fractured clay-rich residuum. An electrolyte solution was eluted through the residuum monolith containing a small emplaced source of coal tar under biologically inhibited and mildly acidic conditions. Concentrations of 10 coal tar compounds, representing mono-, poly-, and heterocyclic aromatic hydrocarbons that constitute crude coal tar were monitored in the effluent over a period of 377 days. Most compounds appeared in the effluent within the first 0.1 pore volume eluted indicating the importance of rapid dissolution and transport through the fracture networks. The concentrations continued to rise but did not reach the corresponding effective solubility limit in most cases. Compounds that were less soluble and those that were more susceptible to sorption or matrix diffusion eluted at a much slower rate. Analysis of contaminant concentrations in microcore residuum samples indicated that all 10 compounds had spread throughout the entire monolith and had diffused into the fine-grained matrix between fractures. These data suggest that the predominantly fine pore structure did not appear to inhibit coal tar dissolution and subsequent transport, even though only a small portion of tar was in direct contact with fractures and macropores that control most flow. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Reduced tar, nicotine, and carbon monoxide exposure while smoking ultralow- but not low-yield cigarettes

    Energy Technology Data Exchange (ETDEWEB)

    Benowitz, N.L.; Jacob, P. III; Yu, L.; Talcott, R.; Hall, S.; Jones, R.T.

    1986-07-11

    An unresolved public health issue is whether some modern cigarettes are less hazardous than other and whether patients who cannot stop smoking should be advised to switch to lower-yield cigarettes. The authors studied tar (estimated by urine mutagenicity), nicotine, and carbon monoxide exposure in habitual smokers switched from their usual brand to high- (15 mg of tar), low- (5 mg of tar), or ultralow-yield (1 mg of tar) cigarettes. There were no differences in exposure comparing high- or low-yield cigarettes, but tar and nicotine exposures were reduced by 49% and 56%, respectively, and carbon monoxide exposure by 36% while smoking ultralow-yield cigarettes. Similarly, in 248 subjects smoking their self-selected brand, nicotine intake, estimated by blood concentrations of its metabolite continine, was 40% lower in those who smoked ultralow but no different in those smoking higher yields of cigarettes. The data indicate that ultralow-yield cigarettes do deliver substantial doses of tar, nicotine, and carbon monoxide, but that exposure are considerably less than for other cigarettes.

  7. Porous Carbon Nanofibers from Electrospun Biomass Tar/Polyacrylonitrile/Silver Hybrids as Antimicrobial Materials.

    Science.gov (United States)

    Song, Kunlin; Wu, Qinglin; Zhang, Zhen; Ren, Suxia; Lei, Tingzhou; Negulescu, Ioan I; Zhang, Quanguo

    2015-07-15

    A novel route to fabricate low-cost porous carbon nanofibers (CNFs) using biomass tar, polyacrylonitrile (PAN), and silver nanoparticles has been demonstrated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers had average diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. After stabilization and carbonization, the resultant CNFs showed more uniformly sized and reduced average diameters (226-507 nm) compared to as-spun nanofibers. The CNFs exhibited high specific surface area (>400 m(2)/g) and microporosity, attributed to the combined effects of phase separations of the tar and PAN and thermal decompositions of tar components. These pore characteristics increased the exposures and contacts of silver nanoparticles to the bacteria including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, leading to excellent antimicrobial performances of as-spun nanofibers and CNFs. A new strategy is thus provided for utilizing biomass tar as a low-cost precursor to prepare functional CNFs and reduce environmental pollutions associated with direct disposal of tar as an industrial waste.

  8. Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Wicakso, Doni Rahmat [Chemical Engineering Department, Faculty of Engineering, Lambung Mangkurat University, Jalan A. Yani KM. 36 Banjarbaru, 70714, South Kalimantan (Indonesia); Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Sutijan; Rochmadi [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Budiman, Arief, E-mail: abudiman@ugm.ac.id [Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jalan Grafika No. 2 Bulaksumur, Yogyakarta, 55281 (Indonesia); Center for Energy Studies, Gadjah Mada University, Sekip K1A, Yogyakarta, 55281 (Indonesia)

    2016-06-03

    Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 – 600 °C and catalyst weight between 0 – 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore pores to from gases, light hydrocarbon (bio-oil) and carbon, thus decreasing content tar in bio-oil and increasing the total gas product. In conclusion, the more low grade iron ore used as catalyst, the tar content in the liquid decrease, the H{sup 2} productivity increased and calorimetric value of bio-oil increased.

  9. Catalytic decomposition of tar derived from wood waste pyrolysis using Indonesian low grade iron ore as catalyst

    Science.gov (United States)

    Wicakso, Doni Rahmat; Sutijan, Rochmadi, Budiman, Arief

    2016-06-01

    Low grade iron ore can be used as an alternative catalyst for bio-tar decomposition. Compared to other catalysts, such as Ni, Rd, Ru, Pd and Pt, iron ore is cheaper. The objective of this research was to investigate the effect of using low grade iron ore as catalyst for tar catalytic decomposition in fixed bed reactor. Tar used in this experiment was pyrolysis product of wood waste while the catalyst was Indonesian low grade iron ore. The variables studied were temperatures between 500 - 600 °C and catalyst weight between 0 - 40 gram. The first step, tar was evaporated at 450 °C to produce tar vapor. Then, tar vapor was flowed to fixed bed reactor filled low grade iron ore. Gas and tar vapor from reactor was cooled, then the liquid and uncondensable gas were analyzed by GC/MS. The catalyst, after experiment, was weighed to calculate total carbon deposited into catalyst pores. The results showed that the tar components that were heavy and light hydrocarbon were decomposed and cracked within the iron ore pores to from gases, light hydrocarbon (bio-oil) and carbon, thus decreasing content tar in bio-oil and increasing the total gas product. In conclusion, the more low grade iron ore used as catalyst, the tar content in the liquid decrease, the H2 productivity increased and calorimetric value of bio-oil increased.

  10. Topical tazarotene vs. coal tar in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, U.; Kaur, I.; Dogra, S.; De, D.; Kumar, B. [Postgraduate Institute of Medical Education & Research, Chandigarh (India)

    2010-07-15

    The efficacy of topical tazarotene has not previously been compared with the conventional topical treatment of crude coal tar (CCT) in stable plaque psoriasis. In this nonblinded side-to-side comparison study, patients with chronic stable plaque psoriasis, who had bilaterally symmetrical plaques on the limbs, applied 0.1% tazarotene gel on the right side and 5% CCT ointment on the left side once daily for 12 weeks followed by an 8-week treatment-free follow up period. Severity of psoriatic lesions and response to treatment was evaluated by scoring erythema, scaling and induration (ESI). Of 30 patients recruited, 27 could be assessed. In the per-protocol analysis, the mean percentage reduction in ESI score at the end of the treatment period was 74.15% {+-} 9.43 and 77.37% {+-} 10.93 with tazarotene and CCT, respectively (P {gt} 0.05). A reduction in ESI score of {gt} 75% was seen in 11 (40.74%) and 16 (59.26%) patients with tazarotene and CCT, respectively, at the end of 12 weeks. Side-effects were seen in 48.14% of patients treated with tazarotene, but in no patient treated with CCT. Tazarotene 0.1% gel has comparable clinical efficacy to CCT 5% ointment. CCT ointment remains a cost-effective therapy for plaque psoriasis.

  11. Kinetics of co-pyrolysis of sawdust, coal and tar.

    Science.gov (United States)

    Montiano, M G; Díaz-Faes, E; Barriocanal, C

    2016-04-01

    Two coals, sawdust and coal tar were selected to prepare briquettes. Thermogravimetric analyses at three heating rates (i.e. 10, 20 and 30°C/min) and up to 1000°C were carried out with the briquette components. Four blends were prepared and the experimental decomposition profiles were compared with the calculated data taking into account the amount of each component in the blend. No interaction was found when comparing the experimental and calculated decomposition profiles of the blends. Isoconversional models OFW (Ozawa-Flynn-Wall) and KAS (Kissinger-Akahira-Sunose) were used to obtain the activation energies of the blend components. The activation energies obtained were introduced in the Coats-Redfern (CR) model to derive the pre-exponential factors. The thermal decomposition profiles calculated using the kinetic parameters were in good agreement with the experimental results in the case of the briquette components, but worse results were obtained in the case of the blends due to their greater complexity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Disturbance of the inclined inserting-type sand fence to wind-sand flow fields and its sand control characteristics

    Science.gov (United States)

    Cheng, Jian-jun; Lei, Jia-qiang; Li, Sheng-yu; Wang, Hai-feng

    2016-06-01

    The inclined inserting-type sand fence is a novel sand retaining wall adopted along the Lanxin High-Speed Railway II in Xinjiang for controlling and blocking sand movement. To verify the effectiveness of the new fence structure for sand prevention, a wind tunnel test was used for flow field test simulation of the sand fence. The results indicate that the inclined inserting-type sand fence was able to deflect the flow of the sand and was able to easily form an upward slant acceleration zone on the leeward side of the sand fence. As shown by the percentage change in sand collection rates on the windward side and the leeward side of the sand fence, the sand flux per unit area at 4 m height in the slant upward direction increased on the leeward side of the inclined inserting-type sand fence. By comparing the flow fields, this site is an acceleration zone, which also reaffirms the correspondence of wind-sand flow fields with the spatial distribution characteristic of the wind-carried sand motion. The field sand collection data indicates that under the effects of the inclined inserting-type sand fence, the sandy air currents passing in front and behind the sand fence not only changed in quality, but the grain composition and particle size also significantly changed, suggesting that the inclined inserting-type sand fence has a sorting and filtering effect on the sandy air currents that passed through. The fence retained coarse particulates on the windward side and fine particulates within the shade of the wind on the leeward side.

  13. Optimal array of sand fences

    Science.gov (United States)

    Lima, Izael A.; Araújo, Ascânio D.; Parteli, Eric J. R.; Andrade, José S.; Herrmann, Hans J.

    2017-03-01

    Sand fences are widely applied to prevent soil erosion by wind in areas affected by desertification. Sand fences also provide a way to reduce the emission rate of dust particles, which is triggered mainly by the impacts of wind-blown sand grains onto the soil and affects the Earth’s climate. Many different types of fence have been designed and their effects on the sediment transport dynamics studied since many years. However, the search for the optimal array of fences has remained largely an empirical task. In order to achieve maximal soil protection using the minimal amount of fence material, a quantitative understanding of the flow profile over the relief encompassing the area to be protected including all employed fences is required. Here we use Computational Fluid Dynamics to calculate the average turbulent airflow through an array of fences as a function of the porosity, spacing and height of the fences. Specifically, we investigate the factors controlling the fraction of soil area over which the basal average wind shear velocity drops below the threshold for sand transport when the fences are applied. We introduce a cost function, given by the amount of material necessary to construct the fences. We find that, for typical sand-moving wind velocities, the optimal fence height (which minimizes this cost function) is around 50 cm, while using fences of height around 1.25 m leads to maximal cost.

  14. Engineering New Catalysts for In-Process Elimination of Tars

    Energy Technology Data Exchange (ETDEWEB)

    Felix, Larry G. [Gas Technology Inst., Des Plaines, IL (United States)

    2012-09-30

    The key objective of this project was to develop a new and more efficient methodology for engineering and economically producing optimized robust catalysts for the reduction or elimination of tars in biomass gasification. Whereas current catalyst technology typically disposes thin layers of catalytically-active material onto rigid supports via wet chemistry-based methods, this project investigated novel thermal methods for directly incorporating catalytically active materials onto robust supports as well as novel approaches for incorporating catalytically active materials on and/or within an otherwise inert refractory support material which is then subsequently formed and processed to create a catalytically-active material on all exposed surfaces. Specifically, the focus of this engineered catalyst development was on materials which were derived from, or otherwise related to, olivine-like minerals, due to the inherent attrition resistance and moderate catalytic properties exhibited by natural olivine when used in a fluidized bed biomass gasifier. Task 1 of this project successfully demonstrated the direct thermal impregnation of catalytically-active materials onto an olivine substrate, with the production of a Ni-olivine catalyst. Nickel and nickel oxide were thermally impregnated onto an olivine substrate and when reduced were shown to demonstrate improved catalytic activity over the baseline olivine material and equal the tar-decomposing performance of Ni-olivine catalysts prepared by conventional wet impregnation. Task 2 involved coordination with our subcontracted project partners to further develop and characterize catalyst formulations and to optimize activity and production methods. Within this task, several significant new materials were developed. NexTech Materials developed a sintered ceramic nickel-magnesium-silicate catalyst that demonstrated superb catalytic activity and high resistance to deactivation by H2S. Alfred University developed both supported

  15. Bacteria of Phlebotominae Sand Flies Collected in Western Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Rafatbakhsh-Iran

    2015-08-01

    Full Text Available Microorganisms particularly bacteria presenting in insects such as Phlebotominae may play an important role in the epidemiology of human infectious disease. Nowadays, because of vector implications, the routine methods of controlling and spraying have no more beneficial effects on vectors and reservoirs. Little knows about the prevalence and diversity of sand fly bacteria. The main objective of this study was to determine the presence of bacteria of phlebotominae sand flies collected in Hamadan, west of Iran. This information is important in order to development of vector control strategies. The microbial flora of Phlebotomus papatasi and P. sergenti the main vector of Cutaneous Leishmaniasis in the old world, were investigated. We characterized 8 bacteria, including 5 Gram-negative bacteria: Acinetobacter lwoffii, Pseudomonas aeruginosa, Enterobacter cloacae, Edvardsiela sp. and Proteus mirabilis and Gram-positive bacteria: Bacillus subtilis, Staphylococcus saprophyticus and Micrococcus luteus. Our study provides some data on the microbiota diversity of field-collected sand flies for the first time in Hamadan. Our results indicate that there is a range of variation of aerobic bacteria inhabiting sand fly, which possibly reflect the ecological condition of the habitat where the fly breeds. Microbiota is increasingly regarded as an important factor for modulating vector competence in insect vectors. So, mirobiota can be effects on the biology of phlebotominae and their roles in the sandfly-Leishmania interaction. Further experiments are required to clearly delineate the vectorial role of sand flies. Because it is probable that in the future, factors such as environmental changes, migration and urbanization can ease the transmission of leishmaniasis in this area.

  16. Studies of RF sheaths and diagnostics on IShTAR

    Energy Technology Data Exchange (ETDEWEB)

    Crombé, K., E-mail: Kristel.Crombe@UGent.be [Department of Applied Physics, Ghent University, Ghent (Belgium); LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Devaux, S.; Faudot, E.; Heuraux, S.; Moritz, J. [YIJL, UMR7198 CNRS-Université de Lorraine, Nancy (France); D’Inca, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Ochoukov, R. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Louche, F.; Tripsky, M.; Van Eester, D.; Wauters, T. [LPP-ERM/KMS, Royal Military Academy, Brussels (Belgium); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, Ghent (Belgium); Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-12-10

    IShTAR (Ion cyclotron Sheath Test ARrangement) is a linear magnetised plasma test facility for RF sheaths studies at the Max-Planck-Institut für Plasmaphysik in Garching. In contrast to a tokamak, a test stand provides more liberty to impose the parameters and gives better access for the instrumentation and antennas. The project will support the development of diagnostic methods for characterising RF sheaths and validate and improve theoretical predictions. The cylindrical vacuum vessel has a diameter of 1 m and is 1.1 m long. The plasma is created by an external cylindrical plasma source equipped with a helical antenna that has been designed to excite the m=1 helicon mode. In inductive mode, plasma densities and electron temperatures have been characterised with a planar Langmuir probe as a function of gas pressure and input RF power. A 2D array of RF compensated Langmuir probes and a spectrometer are planned. A single strap RF antenna has been designed; the plasma-facing surface is aligned to the cylindrical plasma to ease the modelling. The probes will allow direct measurements of plasma density profiles in front of the RF antenna, and thus a detailed study of the density modifications induced by RF sheaths, which influences the coupling. The RF antenna frequency has been chosen to study different plasma wave interactions: the accessible plasma density range includes an evanescent and propagative behaviour of slow or fast waves, and allows the study of the effect of the lower hybrid resonance layer.

  17. Atmospheric tar balls from biomass burning in Mexico

    Science.gov (United States)

    Adachi, Kouji; Buseck, Peter R.

    2011-03-01

    Atmospheric tar balls (TBs) are spherical, organic aerosol particles that occur in smoke from biomass burning (BB). They absorb sunlight and thereby cause warming of the atmosphere. This study reports a transmission electron microscope (TEM) study of TBs from BB smoke samples collected within minutes to hours from emission in a tropical area of Mexico. Their spherical shapes as seen in both scanning electron microscope images and with electron tomography indicate that they were solid when collected. They consist of C and minor O, S, K, and N. The hygroscopic growth factor for our relatively fresh TBs is 1.09 ± 0.04 at a relative humidity of 100%. In samples 1.6 km from the fire, an average of ˜1 and 14%, respectively, of particles with aerodynamic diameter from 50 to 300 nm consisted of TBs. For the latter, more aged samples, the total volume was roughly double that of soot, and their total calculated light absorption at a wavelength of 550 nm was between 74 and 96% that of soot, with the exact amount depending on the size, shape, and coating of the soot. In general, the TBs that we analyzed were similar to those from North America, southern Africa, and Europe in terms of size, external mixing, relative freedom of inclusions, and composition. This and previous studies show that TBs result from a range of biomass fuels. Their distribution from various regions across the globe, combined with their optical properties, suggests they have important effects on regional and perhaps global climate.

  18. Characteristics and Dynamics of a Large Sub-Tidal Sand Wave Field—Habitat for Pacific Sand Lance (Ammodytes personatus, Salish Sea, Washington, USA

    Directory of Open Access Journals (Sweden)

    H. Gary Greene

    2017-10-01

    Full Text Available Deep-water sand wave fields in the San Juan Archipelago of the Salish Sea and Pacific Northwest Washington, USA, have been found to harbor Pacific sand lance (PSL, Ammodytes personatus, a critical forage fish of the region. Little is known of the dynamics of these sand waves and the stability of the PSL sub-tidal habitats. Therefore, we have undertaken an initial investigation to determine the dynamic conditions of a well-known PSL habitat in the San Juan Channel within the Archipelago using bottom sediment sampling, an acoustical doppler current profiling (ADCP system, and multi-beam echo sounder (MBES bathymetry. Our study indicates that the San Juan Channel sand wave field maintained its shape and bedforms geometry throughout the years it has been studied. Based on bed phase diagrams for channelized bedforms, the sand waves appear to be in a dynamic equilibrium condition. Sea level rise may change the current regime within the Archipelago and may alter some of the deep-water or sub-tidal PSL habitats mapped there. Our findings have global significance in that these dynamic bedforms that harbor PSL and sand-eels elsewhere along the west coast of North America and in the North Sea may also be in a marginally dynamic equilibrium condition and may be prone to alteration by sea level rise, indicating an urgency in locating and investigating these habitats in order to sustain the forage fish.

  19. Crystallization and preliminary X-ray diffraction analysis of the periplasmic domain of the Escherichia coli aspartate receptor Tar and its complex with aspartate

    Energy Technology Data Exchange (ETDEWEB)

    Mise, Takeshi; Matsunami, Hideyuki; Samatey, Fadel A.; Maruyama, Ichiro N., E-mail: ichi@oist.jp [Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495 (Japan)

    2014-08-27

    The periplasmic domain of the E. coli aspartate receptor Tar was cloned, expressed, purified and crystallized with and without bound ligand. The crystals obtained diffracted to resolutions of 1.58 and 1.95 Å, respectively. The cell-surface receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni{sup 2+}. To understand the molecular mechanisms underlying the induction of Tar activity by its ligands, the Escherichia coli Tar periplasmic domain with and without bound aspartate (Asp-Tar and apo-Tar, respectively) were each crystallized in two different forms. Using ammonium sulfate as a precipitant, crystals of apo-Tar1 and Asp-Tar1 were grown and diffracted to resolutions of 2.10 and 2.40 Å, respectively. Alternatively, using sodium chloride as a precipitant, crystals of apo-Tar2 and Asp-Tar2 were grown and diffracted to resolutions of 1.95 and 1.58 Å, respectively. Crystals of apo-Tar1 and Asp-Tar1 adopted space group P4{sub 1}2{sub 1}2, while those of apo-Tar2 and Asp-Tar2 adopted space groups P2{sub 1}2{sub 1}2{sub 1} and C2, respectively.

  20. Selected constituents in the smokes of U. S. commercial cigaretts: tar, nicotine, carbon monoxide and carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, R.A.; Quincy, R.B.; Guerin, M.R.

    1979-05-01

    One hundred twenty-one brands of United States commercial cigarettes were analyzed for their deliveries of tar, nicotine, carbon monoxide, and carbon dioxide under standard analytical smoking conditions. The sample included both filter and nonfilter cigarettes. Comparisons of carbon monoxide deliveries over the range of observed tar deliveries indicated a very high correlation between CO and tar for filter cigarettes, but nonfilter cigarettes tended to produce much less CO than would have been predicted from their tar deliveries. Comparison of ORNL nicotine values for specific brands with those determined by the Federal Trade Commission yield no statistically significant differences between laboratories. 4 figures, 6 tables.

  1. Iron(II) supramolecular helicates interfere with the HIV-1 Tat-TAR RNA interaction critical for viral replication

    Science.gov (United States)

    Malina, Jaroslav; Hannon, Michael J.; Brabec, Viktor

    2016-07-01

    The interaction between the HIV-1 transactivator protein Tat and TAR (transactivation responsive region) RNA, plays a critical role in HIV-1 transcription. Iron(II) supramolecular helicates were evaluated for their in vitro activity to inhibit Tat-TAR RNA interaction using UV melting studies, electrophoretic mobility shift assay, and RNase A footprinting. The results demonstrate that iron(II) supramolecular helicates inhibit Tat-TAR interaction at nanomolar concentrations by binding to TAR RNA. These studies provide a new insight into the biological potential of metallosupramolecular helicates.

  2. Use of mineral oil Fleet enema for the removal of a large tar burn: a case report.

    Science.gov (United States)

    Carta, Tricia; Gawaziuk, Justin; Liu, Song; Logsetty, Sarvesh

    2015-03-01

    Extensive hot tar burns are relatively uncommon. Management of these burns provides a significant clinical challenge especially with respect to tar removal involving a large total body surface area (TBSA), without causing further tissue injury. We report a case of an over 40-year old male construction worker who was removing a malfunctioning cap from broken valve. This resulted in tar spraying over the anterior surface of his body including legs, feet, chest, abdomen, arms, face and oral cavity (80% TBSA covered in tar resulting in a 50% TBSA burn injury). Initially, petrolatum-based, double antibiotic ointment was used to remove the tar, based on our previous experience with small tar burns. However, this was time-consuming and ineffective. The tar was easily removed with mineral oil without irritation. In order to meet the demand for quantity of mineral oil, the pharmacy suggested using mineral oil Fleet enema (C.B. Fleet Company, Inc., Lynchburg, Virginia, USA). The squeezable bottle and catheter tip facilitated administration of oil into the patient's construction boots and under clothing that was adhered to the patient's skin. Tar removal requires an effective, non-toxic and non-irritating agent. Mineral oil is such an agent. For patients that may present with a large surface area tar burn, using mineral oil Fleet enema is a viable option that facilitates application into difficult areas. Grant Support: The Firefighters' Burn Fund (Manitoba) supported this project. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  3. Tripeptides from synthetic amino acids block the Tat-TAR association and slow down HIV spread in cell cultures.

    Science.gov (United States)

    Ludwig, Verena; Krebs, Andreas; Stoll, Michaela; Dietrich, Ursula; Ferner, Jan; Schwalbe, Harald; Scheffer, Ute; Dürner, Gerd; Göbel, Michael W

    2007-10-15

    Non-natural amino acids with aromatic or heteroaromatic side chains were incorporated into tripeptides of the general structure Arg-X-Arg and tested as ligands of the HIV RNA element TAR. Some of these compounds could compete efficiently with the association of TAR and Tat and downregulated a TAR-controlled reporter gene in HeLa cells. Peptide 7, which contains a 2-pyrimidinyl-alkyl chain, also inhibited the spread of HIV-1 in cell cultures. NMR studies of 7 bound to HIV-2-TAR gave evidence for contacts in the bulge region.

  4. IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    M. Amzad Hossain

    2010-06-01

    Full Text Available A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC: n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate column was used, followed by glass fiber filter (GFF paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh.   Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS

  5. Settling Tube Analysis of Sand

    NARCIS (Netherlands)

    Geldof, H.J.; Slot, R.E.

    1979-01-01

    For various reasons particle-size analysis of sediment is used in many fields of science and technology, a.o. earth sciences, agricultural and civil engineering. Relatively coarse-grained sediment like sand, with dimensions ranging from 0.06 till 2 mm, is analyzed almost exclusively by sieving. The

  6. Silo model tests with sand

    DEFF Research Database (Denmark)

    Munch-Andersen, Jørgen

    Tests have been carried out in a large silo model with Leighton Buzzard Sand. Normal pressures and shear stresses have been measured during tests carried out with inlet and outlet geometry. The filling method is a very important parameter for the strength of the mass and thereby the pressures...

  7. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  8. V-2 at White Sands

    Science.gov (United States)

    1947-01-01

    A V-2 rocket is hoisted into a static test facility at White Sands, New Mexico. The German engineers and scientists who developed the V-2 came to the United States at the end of World War II and continued rocket testing under the direction of the U. S. Army, launching more than sixty V-2s.

  9. UTILIZATION OF ACTIVATED ZEOLITE AS MOLECULAR SIEVE IN CHROMATOGRAPHIC COLUMN FOR SEPARATION OF COAL TAR COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Dwi Retno Nurotul Wahidiyah

    2010-06-01

    Full Text Available Application of activated zeolite (ZAA as molecular sieve to separate compounds of coal tar from vaccum fractional distillation, have been done. The size of zeolite was 10-20 mesh and used as solid phase in column chromatography with length of 30 cm. The first step of the research was coal pyrolisis and the product (tar was distillated by fractional column and vaccum system at reduced pressure 44 cmHg and maximum temperature at 200 oC. The distillate from this procedure was flowed to the column chromatography of zeolite (ZAA. The compound absorbed by zeolite was eluted with varying solvents, i.e: CCl4, acetone and ethanol. Each fraction was then analyzed by gas chromatography. The results showed, zeolite have a capability to separate the compounds of tar and it tends to absorb medium hydrocarbon. The nonpolar eluent [CCl4] gives the better result in eluting tar compound than polar (ethanol or medium polar eluents (acetone.   Keywords: zeolite, coal tar, column chromatography

  10. Syngas production from tar reforming by microwave plasma jet at atmospheric pressure: power supplied influence

    Science.gov (United States)

    de Souza Medeiros, Henrique; Justiniano, Lucas S.; Gomes, Marcelo P.; Soares da Silva Sobrinho, Argemiro; Petraconi Filho, Gilberto

    2013-09-01

    Now a day, scientific community is searching for new fuels able to replace fossil fuels with economic and environment gains and biofuel play a relevant rule, mainly for the transport sector. A major process to obtaining such type of renewable resource is biomass gasification. This process has as product a gas mixture containing CO, CH4, and H2 which is named synthesis gas (syngas). However, an undesirable high molecular organic species denominated tar are also produced in this process which must be removed. In this work, results of syngas production via tar reforming in the atmospheric pressure microwave discharge having as parameter the power supply. Argon, (argon + ethanol), and (argon + tar solution) plasma jet were produced by different values of power supplied (from 0.5 KW to 1.5 KW). The plasma compounds were investigated by optical spectroscopy to each power and gas composition. The main species observed in the spectrum are Ar, CN, OII, OIV, OH, H2, H(beta), CO2, CO, and SIII. This last one came from tar. The best value of the power applied to syngas production from tar reforming was verified between 1.0 KW and 1.2 KW. We thank the following institutions for financial support: CNPq, CAPES, and FAPESP.

  11. Tar reduction in pyrolysis vapours from biomass over a hot char bed.

    Science.gov (United States)

    Gilbert, P; Ryu, C; Sharifi, V; Swithenbank, J

    2009-12-01

    The behaviour of pyrolysis vapours over char was investigated in order to maximise tar conversion for the development of a new fixed bed gasifier. Wood samples were decomposed at a typical pyrolysis temperature (500 degrees C) and the pyrolysis vapours were then passed directly through a tar cracking zone in a tubular reactor. The product yields and properties of the condensable phases and non-condensable gases were studied for different bed lengths of char (0-450 mm), temperatures (500-800 degrees C), particle sizes (10 and 15 mm) and nitrogen purge rates (1.84-14.70 mm/s). The carbon in the condensable phases showed about 66% reduction by a 300 mm long char section at 800 degrees C, compared to that for pyrolysis at 500 degrees C. The amount of heavy condensable phase decreased with increasing temperature from about 18.4 wt% of the biomass input at 500 degrees C to 8.0 wt% at 800 degrees C, forming CO, H(2) and other light molecules. The main mode of tar conversion was found to be in the vapour phase when compared to the results without the presence of char. The composition of the heavy condensable phase was simplified into much fewer secondary and tertiary tar components at 800 degrees C. Additional measures were required to maximise the heterogeneous effect of char for tar reduction.

  12. Decomposition of tar in gas from updraft gasifier by thermal cracking

    DEFF Research Database (Denmark)

    Brandt, Peder; Henriksen, Ulrik Birk

    2000-01-01

    Continuing earlier work with tar reduction by partial oxidation of pyrolysis gas [1] thermal cracking has been evaluated as a gas cleaning process. The work has been focusing on cleaning gas from updraft gasifiers, and the long term purpose is to develop a tar cleaning unit based on thermal...... cracking. An experimental set-up has been built, in which a flow of contaminated gas can be heated up to 1290°C in a reactor made of pure Al2O3. Four measurements were made. Three with gas from a pyrolysis unit simulating updraft gasifier, and one with gas from an updraft gasifier. Cracking temperatures...... was 1200, 1250 and 1290°C, and the residence time at this temperature was 0.5 second. The measurements show that at the selected residence time of 0.5 second, the gas flow in a thermal tar cracking unit has to be heated to at least 1250°C to achieve sufficient tar cleaning. At 1290°C, a tar content as low...

  13. Source investigation of the tar balls deposited along the Gujarat coast, India, using chemical fingerprinting and transport modeling techniques.

    Science.gov (United States)

    Suneel, V; Vethamony, P; Naik, B G; Kumar, K Vinod; Sreenu, L; Samiksha, S V; Tai, Yunus; Sudheesh, K

    2014-10-07

    Deposition of tar balls (TBs) along the south Gujarat coast, situated on the west coast of India (WCI), commonly occurs during the southwest monsoon season. Several offshore oil fields off the Mumbai-Gujarat coast, and refineries along the coast might be sources of oil spills/leakages and lead to the formation of TBs. To identify the sources, we collected 12 TB samples from the beaches of Gujarat (Tithal, Maroli, Umbergam, and Nargol) during 15-17 July 2012 as well as samples of crude oils, namely, Cairn, NIKO, MSC Chitra, and two at Bombay High (BH). These TBs were subject to the following multimarker approach for source identification: Diagnostic Ratios of n-alkanes, polycyclic aromatic hydrocarbons, pentacyclic triterpanes, compound specific isotope analysis, Principle Component Analysis and numerical simulations (hydrodynamic model coupled with particle trajectories). The chemical fingerprint results reveal that the source of the TBs is BH crude oils, and the model results confirm that the source location is BH north oil fields. This is the first study of its kind in India to use fingerprinting and transport modeling techniques for source identification of TBs.

  14. The eolian sand problems arising from desertification.

    Science.gov (United States)

    Bofah, K K; Owusu, Y A

    1986-05-01

    Eolian (wind blown) sand constitutes a very serious problem to development in sandy desert lands and causes equally serious problems in lands that are undergoing desertification. In this paper, eolian sand movement due to bulk movement such as sand dune and ripple movement, sand drift by saltation, and sand storms by strong winds are discussed. Associated problems such as eolian sand encroachment on highways, farms, communities and industrial complexes are also discussed and workable solutions are offered. Solutions include chemical stabilization of the surface grains, fences to trap the blown sand and vegetation to prevent soil deflation. Vegetation is emphasized and recommended as the ultimate viable solution to combat desertification and eolian sand problems.

  15. Technological changes illustrated by the coal tar and tar dye industry; Die Wandlung der Technik am Beispiel der Steinkohlenteer- und Teerfarben-Chemie

    Energy Technology Data Exchange (ETDEWEB)

    Collin, G. [Deutsche Gesellschaft fuer Chemisches Apparatewesen, Chemische Technik und Biotechnologie e.V. (DECHEMA), Frankfurt am Main (Germany)

    2001-05-01

    Coal tar was detected in the 17th century in laboratory experiments based on empirical knowledge. In the 18th century industrial revolution, coal tar was an undesired by-product of iron production and coking plants. It was first used in the 19th century for impregnating railway sleepers. Later developments in atomic theory, new chemical symbols and organic element analysis provided the basis for discovering and chemical characterisation of coal tar constituents. Laboratory experiments with these tar constituents resulted in the first synthetic dyes, the postulation of tetravalent carbon and the resulting structural theory in organic chemistry for systematic synthesis of many tar dyes to substitute natural dyes in the textile industry. The technical application of these syntheses was part 2 of the industrial revolution and the foundation of the chemical industry in Germany, which developed rapidly in the 2nd half of the 19th century. Tar dye chemistry has made a significant contribution to Germany's economic growth and the change from an agricultural to an industrialized country. [German] Die Entdeckung des Steinkohlenteers im 17. Jahrhundert basiert auf durch Erfahrungswissen gepraegten Laboratoriumsexperimenten. Im Verlauf der 'Industriellen Revolution' des 18. Jahrhunderts ist der Steinkohlenteer zunaechst ein laestiges Abfallprodukt der Eisengewinnung im Kokshochofen und der Leuchtgasherstellung durch Kohlenverkokung. Erste technische Applikation finden Steinkohlenteeroele im 19. Jahrhundert durch den Eisenbahnbau zur Langzeit-Konservierung der dafuer benoetigten Holzschwellen. Die wissenschaftlichen Erfkenntnisse zur Atomtheorie, eine neue chemische Zeichensprache und die organische Elementaranalyse werden Voraussetzungen zur Entdeckung und chemischen Charakterisierung der Hauptinhaltsstoffe des Steinkohlenteers. Laboratoriumsexperimente mit den entdeckten Teerinhaltsstoffen fuehren zur Erfindung der ersten synthetischen Farbstoffe, die

  16. experimental studies of sand production from unconsolidated

    African Journals Online (AJOL)

    ES Obe

    consolidated samples has been used to simulate the effect of flow rates, confining pressure, pressure drawdown and fluid viscosity on sand production in the Niger. Delta. The model was also used to determine the ability of using the flow rate to control the production of sand. Sand sample from an unconsolidated reser-.

  17. Microplastic and tar pollution on three Canary Islands beaches: An annual study.

    Science.gov (United States)

    Herrera, A; Asensio, M; Martínez, I; Santana, A; Packard, T; Gómez, M

    2017-10-26

    Marine debris accumulation was analyzed from three exposed beaches of the Canary Islands (Lambra, Famara and Las Canteras). Large microplastics (1-5mm), mesoplastics (5-25mm) and tar pollution were assessed twice a month for a year. There was great spatial and temporal variability in the Canary Island coastal pollution. Seasonal patterns differed at each location, marine debris concentration depended mainly of local-scale wind and wave conditions. The most polluted beach was Lambra, a remote beach infrequently visited. The types of debris found were mainly preproduction resin pellets, plastic fragments and tar, evidencing that pollution was not of local origin, but it cames from the open sea. The levels of pollution were similar to those of highly industrialized and contaminated regions. This study corroborates that the Canary Islands are an area of accumulation of microplastics and tar rafted from the North Atlantic Ocean by the southward flowing Canary Current. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Coal tar creosote abuse by vapour inhalation presenting with renal impairment and neurotoxicity: a case report

    Directory of Open Access Journals (Sweden)

    Hiemstra Thomas F

    2007-09-01

    Full Text Available Abstract A 56 year old aromatherapist presented with advanced renal failure following chronic coal tar creosote vapour inhalation, and a chronic tubulo-interstitial nephritis was identified on renal biopsy. Following dialysis dependence occult inhalation continued, resulting in seizures, ataxia, cognitive impairment and marked generalised cerebral atrophy. We describe for the first time a case of creosote abuse by chronic vapour inhalation, resulting in significant morbidity. Use of the polycyclic aromatic hydrocarbon-containing wood preservative coal tar creosote is restricted by many countries due to concerns over environmental contamination and carcinogenicity. This case demonstrates additional toxicities not previously reported with coal tar creosote, and emphasizes the health risks of polycyclic aromatic hydrocarbon exposure.

  19. Numerical simulation of vortex pyrolysis reactors for condensable tar production from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.S.; Bellan, J. [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.

    1998-08-01

    A numerical study is performed in order to evaluate the performance and optimal operating conditions of vortex pyrolysis reactors used for condensable tar production from biomass. A detailed mathematical model of porous biomass particle pyrolysis is coupled with a compressible Reynolds stress transport model for the turbulent reactor swirling flow. An initial evaluation of particle dimensionality effects is made through comparisons of single- (1D) and multi-dimensional particle simulations and reveals that the 1D particle model results in conservative estimates for total pyrolysis conversion times and tar collection. The observed deviations are due predominantly to geometry effects while directional effects from thermal conductivity and permeability variations are relatively small. Rapid ablative particle heating rates are attributed to a mechanical fragmentation of the biomass particles that is modeled using a critical porosity for matrix breakup. Optimal thermal conditions for tar production are observed for 900 K. Effects of biomass identity, particle size distribution, and reactor geometry and scale are discussed.

  20. Synthesis of organic soluble poly(substituted-aniline) from 2-methyl-6-ethylaniline tar

    Science.gov (United States)

    Liu, Yuan; Li, Shu-Bai; Yao, Pei; Zhang, Qi-Meng

    2017-07-01

    Organic soluble poly(substituted-aniline) was synthesized by chemical oxidative polymerization from 2-methyl-6-ethylaniline tar. The structural information of samples was characterized using FT-IR and SEM techniques. The influences of acid concentration, mole ratio of oxidants to tar, reaction time and temperature were investigated. The solubility of polymers was also studied. The results indicate that the conductivity of poly(substituted-aniline) could reach 2.51 ×-4 S ṡ cm-1 under the reaction conditions with 1 mol./L hydrochloric acid, mole ratio of oxidants to tar = 1, and at 10∘C for 3 h. The polymers show better solubility than polyaniline in most organic solvents.

  1. Preparation of spherical activated phenol-formaldehyde beads from bamboo tar for adsorption of toluene.

    Science.gov (United States)

    Huang, Ying-Pin; Hsi, Hsing-Cheng; Liu, Szu-Chen

    2013-08-01

    Bamboo tar is a waste by-product from the process of bamboo charcoal production. After distillation under reduced pressure, bamboo tar becomes a highly viscous liquid containing phenolic compounds at more than 70 wt%. Therefore, bamboo tar could be an excellent replacement for the phenolic compounds produced by the decomposition of petroleum. In this study, bamboo tar was mixed with formalin under a weak alkaline condition to form cured phenol-formaldehyde (PF) beads through suspension polymerization. In total, 35% of the obtained PF resin produced spherical beads with a particle size ranging from 9 to 16 mesh. The char yield after 500 degrees C carbonization was 60.4 wt%, according to thermogravimetric analysis. This high char yield is advantageous for the subsequent activation process. After physical activation using CO2 at 900 degrees C for 2 hr the carbide yield was up to 73.0 wt%. The specific surface area of activated PF beads was dependent on the activation time and temperature. Toluene adsorption results suggest that the activated PF beads are applicable to the adsorption and recovery of VOC gases. Monolayer adsorption may limit the VOC adsorption with activated PF beads because the adsorption isotherms were better fitted with the Langmuir model. Bamboo tar is shown to be a good replacement for the phenolic compounds from decomposition of petroleum to form activated phenol-formaldehyde (PF) beads. Toluene adsorption tests suggest that the activated PF beads have potential to adsorb and recover VOC gases. Nevertheless, due to the low specific surface area of the activated PF beads from bamboo tar, a further enhancement in both meso- and microporosity is needed in the future experiments. The experimental data provide a contribution to better understanding the possibility of resource recovery of waste agricultural by-products and their potential application in environment protection.

  2. TAR cloning: insights into gene function, long-range haplotypes and genome structure and evolution.

    Science.gov (United States)

    Kouprina, Natalay; Larionov, Vladimir

    2006-10-01

    The structural and functional analysis of mammalian genomes would benefit from the ability to isolate from multiple DNA samples any targeted chromosomal segment that is the size of an average human gene. A cloning technique that is based on transformation-associated recombination (TAR) in the yeast Saccharomyces cerevisiae satisfies this need. It is a unique tool to selectively recover chromosome segments that are up to 250 kb in length from complex genomes. In addition, TAR cloning can be used to characterize gene function and genome variation, including polymorphic structural rearrangements, mutations and the evolution of gene families, and for long-range haplotyping.

  3. Pyrolysis of automotive shredder residue light fraction: maximization of the tar yield using design of experiment

    Science.gov (United States)

    Anzano, Manuela; Collina, Elena; Piccinelli, Elsa; Lasagni, Marina

    2017-05-01

    The general aim of this study is the valorisation of Automotive Shredder Residue (ASR) via pyrolysis. Tar, the condensable gases obtained in the pyrolysis process, is an interesting alternative fuel. Thus, the pyrolysis process was investigated in order to maximize the tar yield. The design of experiment approach was used to plan a series of experiments and to identify which operating variables influence the yield of the process. Temperature and carrier gas flow proved to be significant factors affecting the yield, while the influence of ASR light fraction amount pyrolysed was negligible. In the experimental domain, the maximum response was obtained at 500 °C and 100 mL/min.

  4. Risk Assessment for Children Exposed to Beach Sands Impacted by Oil Spill Chemicals

    Directory of Open Access Journals (Sweden)

    Jennifer C. Black

    2016-08-01

    Full Text Available Due to changes in the drilling industry, oil spills are impacting large expanses of coastlines, thereby increasing the potential for people to come in contact with oil spill chemicals. The objective of this manuscript was to evaluate the health risk to children who potentially contact beach sands impacted by oil spill chemicals from the Deepwater Horizon disaster. To identify chemicals of concern, the U.S. Environmental Protection Agency’s (EPA’s monitoring data collected during and immediately after the spill were evaluated. This dataset was supplemented with measurements from beach sands and tar balls collected five years after the spill. Of interest is that metals in the sediments were observed at similar levels between the two sampling periods; some differences were observed for metals levels in tar balls. Although PAHs were not observed five years later, there is evidence of weathered-oil oxidative by-products. Comparing chemical concentration data to baseline soil risk levels, three metals (As, Ba, and V and four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, and dibenz[a,h]anthracene were found to exceed guideline levels prompting a risk assessment. For acute or sub-chronic exposures, hazard quotients, computed by estimating average expected contact behavior, showed no adverse potential health effects. For cancer, computations using 95% upper confidence limits for contaminant concentrations showed extremely low increased risk in the 10−6 range for oral and dermal exposure from arsenic in sediments and from dermal exposure from benzo[a]pyrene and benz[a]anthracene in weathered oil. Overall, results suggest that health risks are extremely low, given the limitations of available data. Limitations of this study are associated with the lack of toxicological data for dispersants and oil-spill degradation products. We also recommend studies to collect quantitative information about children’s beach play habits, which are

  5. Reframing the Canadian Oil Sands

    OpenAIRE

    Patchett, Merle M; Lozowy, A

    2012-01-01

    Reframing the Canadian Oil Sands” is a collaborative exchange between photographer Andriko Lozowy and cultural geographer Merle Patchett that engages photography and photographic theory to evoke a more critical and politically meaningful visual engagement with the world’s largest capital oil project. Since the appearance of Edward Burtynsky’s aerial and abstracted photographic-mappings of the region, capturing the scale of the Oil Sands from ‘on high’ has become the dominant visual imaginary....

  6. 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 quantify...... module for characterizing granular materials. The new module enables viscosity measurements of the green sand as function of the shear rate at different flow rates, i.e. 0, 2, 4, 6, 8, 10, 12 and 15 L/min. The results show generally that the viscosity decreases with both the shear- and flow rate....... In addition, the measurements show that the green sand flow follows a shear-thinning behaviour even after the full fluidization point....

  7. Role of Sand Grains in Sorption Processes by Surface Layers of Components of Sand Moulds

    Directory of Open Access Journals (Sweden)

    Kaźnica N.

    2017-03-01

    Full Text Available The results of researches of sorption processes of surface layers of components of sand moulds covered by protective coatings are presented in the hereby paper. Investigations comprised various types of sand grains of moulding sands with furan resin: silica sand, reclaimed sand and calcined in temperature of 700°C silica sand. Two kinds of alcoholic protective coatings were used - zirconium and zirconium - graphite. Tests were performed under condition of a constant temperature within the range 30 - 35°C and high relative air humidity 75 - 80%. To analyze the role of sand grains in sorption processes quantitavie moisture sorption with use of gravimetric method and ultrasonic method were used in measurements. The tendency to moisture sorption of surface layers of sand moulds according to the different kinds of sand grains was specified. The effectiveness of protective action of coatings from moisture sorption was analyzed as well.

  8. Evaluation of Durability Parameters of Concrete with Manufacture Sand and River Sand

    Science.gov (United States)

    Sangoju, Bhaskar; Ramesh, G.; Bharatkumar, B. H.; Ramanjaneyulu, K.

    2017-09-01

    Most of the states in our country have banned sand quarrying from the river beds, causing a scarcity of natural river sand for the construction sector. Manufacture sand (M-sand) is one of the alternate solutions to replace the river sand (R-sand) in concrete. The main aim of the present study is to evaluate the durability parameters of concrete with M-sand when compared to that of concrete with R-sand. Corrosion of reinforcement is one of the main deteriorating mechanisms of reinforced concrete due to the ingress of chloride ions or carbon-di-oxide. For comparative evaluation of durability parameters, accelerated tests such as Rapid Chloride Permeability Test, Rapid Chloride Migration Test and accelerated carbonation test were carried out on specimens of R-sand and M-sand. All tests were carried out after 90 days of casting. Test results reveal that the durability parameters of the concrete with M-sand in chloride induced environment is relatively better than that of concrete with R-sand and hence is recommended to use M-sand as a replacement to R-sand.

  9. Coal-tar-based pavement sealants—a potent source of PAHs

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.

    2017-01-01

    P avement sealants are applied to the asphalt pavement of many parking lots, driveways, and even playgrounds in North America (Figure 1), where, when first applied, they render the pavement glossy black and looking like new. Sealant products used commercially in the central, eastern, and northern United States typically are coal-tarbased, whereas those used in the western United States typically are asphalt-based. Although the products look similar, they are chemically different. Coal-tarbased pavement sealants typically are 25-35 percent (by weight) coal tar or coal-tar pitch, materials that are known human carcinogens and that contain high concentrations of polycyclic aromatic hydrocarbons (PAHs) and related chemicals (unless otherwise noted, all Figure 1. Pavement sealant is commonly used to seal parking lots, playgrounds, and driveways throughout the United States. Sealants used in the central, northern, eastern, and southern United States typically contain coal tar or coal-tar pitch, both of which are known human carcinogens. Photos by the U.S. Geological Survey. data in this article are from Mahler et al. 2012 and references therein).

  10. Gc/ms analysis of coal tar composition produced from coal

    African Journals Online (AJOL)

    2005-11-17

    Technology, Hubei Province, Wuhan, China. (Received November 17, 2005; revised December 22, 2006). ABSTRACT. Coal tar is a significant product generated from coal pyrolysis. A detailed analytical study on its composition and chemical structure will be of great advantage to its further processing and utilization.

  11. Application of Cigarette Smoke Characterisation Based on Optical Aerosol Spectrometry. Dynamics and Comparisons with Tar Values

    NARCIS (Netherlands)

    Dijk, W.D. van; Cremers, R.; Klerx, W.; Schermer, T.R.J.; Scheepers, P.T.J.

    2012-01-01

    Introduction: Cigarette smoking causes devastating disease worldwide. Current cigarette classification is based on standardised tar mass values obtained from smoking-machines. However, their ability to predict disease is poor, and these mass values are primarily determined by larger particles. The

  12. gc/ms analysis of coal tar composition produced from coal pyrolysis

    African Journals Online (AJOL)

    Coal tar is a significant product generated from coal pyrolysis. A detailed analytical study on its composition and chemical structure will be of great advantage to its further processing and utilization. Using a combined method of planigraphy-gas chromatograph/mass spectroscopy (GC/MS), this work presents a composition ...

  13. Carbon deposition in an SOFC fueled by tar-laden biomass gas: a thermodynamic analysis

    Science.gov (United States)

    Singh, Devinder; Hernández-Pacheco, Eduardo; Hutton, Phillip N.; Patel, Nikhil; Mann, Michael D.

    This work presents a thermodynamic analysis of the carbon deposition in a solid oxide fuel cell (SOFC) fueled by a biomass gasifier. Integrated biomass-SOFC units offer considerable benefits in terms of efficiency and fewer emissions. SOFC-based power plants can achieve a system efficiency of 70-80% (including heat utilization) as compared to 30-37% for conventional systems. The fuel from the biomass gasifier can contain considerable amounts of tars depending on the type of gasifier used. These tars can lead to the deposition of carbon at the anode side of SOFCs and affect the performance of the fuel cells. This paper thermodynamically studies the risk of carbon deposition due to the tars present in the feed stream and the effect various parameters like current density, steam, and temperature have on carbon deposition. Since tar is a complex mixture of aromatics, it is represented by a mixture of toluene, naphthalene, phenol, and pyrene. A total of 32 species are considered for the thermodynamic analysis, which is done by the Gibbs energy minimization technique. The carbon deposition is shown to decrease with an increase in current density and becomes zero after a critical current density. Steam in the feed stream also decreases the amount of carbon deposition. With the increase in temperature the amount of carbon first decreases and then increases.

  14. Low Temperature Particle Filtration of Wood Gas with Low Tar Content

    DEFF Research Database (Denmark)

    Hindsgaul, Claus; Henriksen, Ulrik Birk; Bentzen, Jens Dall

    2002-01-01

    Baghouse filters and cartridge filters were tested online with wood gas from a two stage down draft gasifier. The gas contained soot and very low levels (10-30 mg/Nm³) of tar. Particle collection efficiencies were above 95%. Continuous operation with cheap self cleaning baghouse filters were tested...

  15. Tar analysis from biomass gasification by means of online fluorescence spectroscopy

    Science.gov (United States)

    Baumhakl, Christoph; Karellas, Sotirios

    2011-07-01

    Optical methods in gas analysis are very valuable mainly due to their non-intrusive character. That gives the possibility to use them for in-situ or online measurements with only optical intervention in the measurement volume. In processes like the gasification of biomass, it is of high importance to monitor the gas quality in order to use the product gas in proper machines for energy production following the restrictions in the gas composition but also improving its quality, which leads to high efficient systems. One of the main problems in the biomass gasification process is the formation of tars. These higher hydrocarbons can lead to problems in the operation of the energy system. Up to date, the state of the art method used widely for the determination of tars is a standardized offline measurement system, the so-called "Tar Protocol". The aim of this work is to describe an innovative, online, optical method for determining the tar content of the product gas by means of fluorescence spectroscopy. This method uses optical sources and detectors that can be found in the market at low cost and therefore it is very attractive, especially for industrial applications where cost efficiency followed by medium to high precision are of high importance.

  16. Gasification and effect of gasifying temperature on syngas quality and tar generation: A short review

    Science.gov (United States)

    Guangul, Fiseha Mekonnen; Sulaiman, Shaharin Anwar; Raghavan, Vijay R.

    2012-06-01

    Corrosion, erosion and plugging of the downstream equipments by tar and ash particle and, low energy content of syngas are the main problems of biomass gasification process. This paper attempts to review the findings of literature on the effect of temperature on syngas quality, and in alleviating the tar and ash problems in the gasification process. The review of literature indicates that as the gasification temperature increases, concentration of the resulting H2 and carbon conversion efficiency increase, the amount of tar in the syngas decreases. For the same condition, CH4 and CO concentration do not show consistent trend when the feedstock and gasification process varies. These necessitate the need for conducting an experiment for a particular gasification process and feedstock to understand fully the benefits of controlling the gasification temperature. This paper also tries to propose a method to improve the syngas quality and to reduce the tar amount by using preheated air and superheated steam as a gasifying media for oil palm fronds (OPF) gasification.

  17. Influence of Operation Conditions on Carbon Deposition in SOFCs Fuelled by Tar-Containing Biosyngas

    NARCIS (Netherlands)

    Liu, M.; Millan-Agorio, M.G.; Aravind, P.V.; Brandon, N.P.

    2011-01-01

    This paper presents the influence of operation conditions including steam levels, current density and operating time on the performance of Solid Oxide Fuel Cells (SOFCs) fuelled by tar- containing biosyngas. The performance of SOFCs was evaluated by means of recording impedance spectra and

  18. 78 FR 41691 - Safety Zone; Pamlico River and Tar River; Washington, NC

    Science.gov (United States)

    2013-07-11

    ... ``SEARCH'' box and click ``SEARCH.'' Click on Open Docket Folder on the line associated with this... display originating from latitude 35 32'25'' N, longitude 077 03'42'' W. The fireworks debris fallout area... and Tar Rivers within a 300 yards radius of latitude 35 32'25'' N, longitude 077 03'42'' W. This...

  19. Coal-tar-based pavement sealcoat, polycyclic aromatic Hydrocarbons (PAHs), and environmental health

    Science.gov (United States)

    Mahler, B.J.; Van Metre, P.C.

    2011-01-01

    Studies by the U.S. Geological Survey (USGS) have identified coal-tar-based sealcoat-the black, viscous liquid sprayed or painted on asphalt pavement such as parking lots-as a major source of polycyclic aromatic hydrocarbon (PAH) contamination in urban areas for large parts of the Nation. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

  20. SAND

    DEFF Research Database (Denmark)

    Thorsen, Grete

    Der er udført et konsolideringsforsøg med bakkesand fra Lunds grusgrav, Lund no. O. forsøget er udført i samme konsolideringsapparat, som er anvendt til måling af deformationsegenskaberne af mange forskellige danske jordarter. Forsøgsresultaterne er søgt tolket som ved forsøg med andre jordarter....

  1. TarNet: An Evidence-Based Database for Natural Medicine Research.

    Directory of Open Access Journals (Sweden)

    Ruifeng Hu

    Full Text Available Complex diseases seriously threaten human health. Drug discovery approaches based on "single genes, single drugs, and single targets" are limited in targeting complex diseases. The development of new multicomponent drugs for complex diseases is imperative, and the establishment of a suitable solution for drug group-target protein network analysis is a key scientific problem that must be addressed. Herbal medicines have formed the basis of sophisticated systems of traditional medicine and have given rise to some key drugs that remain in use today. The search for new molecules is currently taking a different route, whereby scientific principles of ethnobotany and ethnopharmacognosy are being used by chemists in the discovery of different sources and classes of compounds.In this study, we developed TarNet, a manually curated database and platform of traditional medicinal plants with natural compounds that includes potential bio-target information. We gathered information on proteins that are related to or affected by medicinal plant ingredients and data on protein-protein interactions (PPIs. TarNet includes in-depth information on both plant-compound-protein relationships and PPIs. Additionally, TarNet can provide researchers with network construction analyses of biological pathways and protein-protein interactions (PPIs associated with specific diseases. Researchers can upload a gene or protein list mapped to our PPI database that has been manually curated to generate relevant networks. Multiple functions are accessible for network topological calculations, subnetwork analyses, pathway analyses, and compound-protein relationships.TarNet will serve as a useful analytical tool that will provide information on medicinal plant compound-affected proteins (potential targets and system-level analyses for systems biology and network pharmacology researchers. TarNet is freely available at http://www.herbbol.org:8001/tarnet, and detailed tutorials on the

  2. Historical overview of the Fort McMurray area and oil sands industry in northeast Alberta[With expanded bibliographies on oil sands, surficial geology, hydrogeology, minerals and bedrock in northeast Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Hein, F.J. [Alberta Geological Survey, Edmonton, AB (Canada). Resources Branch

    2000-05-01

    The Athabasca region of northeast Alberta was originally inhabited by First Nations and Metis people, specifically Dene and Chipewyan people. The first known sample of oil saturated, bituminous sand to ever reach a European was delivered in 1719 to Henry Kelsey, manager of the York Factory on Hudson's Bay. The first written occurrence took place in 1778 by Peter Pond. Explorations took place in the ensuing years in the region of the Athabasca River between Lake Athabasca and the confluence of the Athabasca and Clearwater rivers. A fur trading post was founded in 1870 at the confluence of the two rivers (Athabasca and Clearwater) and named Fort McMurray. The fur trading post was closed in 1898 and reopened in 1912 to serve as a large-freight storage warehouse. A salt mine was opened in the vicinity in 1925, and the industry operated on and off until 1950. The author then provided an overview of the oil sands industry in the area. In 1882, specimens oi oil sands were identified as Lower Cretaceous in age by Dr. Bell who then suggested that the source was located in the Devonian strata. Some experiments were conducted with hot water in the hope of separating the bitumen from the sand. Around 1930, the Father of the Oil Sands, a man named Sidney Ells, began a detailed survey of the oil sands of the Athabasca River valley. To demonstrate the potential uses of the tar sands, Ells laid bituminous pavement in Edmonton and Jasper National Park. A number of other scientists experimented with their own methods for producing oil from the bitumen at several research facilities, most notably Sidney Blair at the University of Alberta, whose work forms the basis for the thermal-extraction processes currently in use in the industry. The Alberta Oil Sands Technology and Research Authority (AOSTRA) was formed in 1974 with the aim of providing funding and synergies for research in the field of bitumen extraction and upgrading. Suncor and Syncrude have both produced synthetic

  3. Pyrolysis of aseptic packages (tetrapak) in a laboratory screw type reactor and secondary thermal/catalytic tar decomposition.

    Science.gov (United States)

    Haydary, J; Susa, D; Dudáš, J

    2013-05-01

    Pyrolysis of aseptic packages (tetrapak cartons) in a laboratory apparatus using a flow screw type reactor and a secondary catalytic reactor for tar cracking was studied. The pyrolysis experiments were realized at temperatures ranging from 650 °C to 850 °C aimed at maximizing of the amount of the gas product and reducing its tar content. Distribution of tetrapak into the product yields at different conditions was obtained. The presence of H2, CO, CH4, CO2 and light hydrocarbons, HCx, in the gas product was observed. The Aluminum foil was easily separated from the solid product. The rest part of char was characterized by proximate and elemental analysis and calorimetric measurements. The total organic carbon in the tar product was estimated by elemental analysis of tars. Two types of catalysts (dolomite and red clay marked AFRC) were used for catalytic thermal tar decomposition. Three series of experiments (without catalyst in a secondary cracking reactor, with dolomite and with AFRC) at temperatures of 650, 700, 750, 800 and 850 °C were carried out. Both types of catalysts have significantly affected the content of tars and other components in pyrolytic gases. The effect of catalyst on the tetrapack distribution into the product yield on the composition of gas and on the total organic carbon in the tar product is presented in this work. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. In silico Analyses of Subtype Specific HIV-1 Tat-TAR RNA Interaction Reveals the Structural Determinants for Viral Activity

    Directory of Open Access Journals (Sweden)

    Larance Ronsard

    2017-08-01

    Full Text Available HIV-1 Tat transactivates viral genes through strong interaction with TAR RNA. The stem-loop bulged region of TAR consisting of three nucleotides at the position 23–25 and the loop region consisting of six nucleotides at the position 30–35 are essential for viral transactivation. The arginine motif of Tat (five arginine residues on subtype TatC is critically important for TAR interaction. Any mutations in this motif could lead to reduce transactivation ability and pathogenesis. Here, we identified structurally important residues (arginine and lysine residues of Tat in this motif could bind to TAR via hydrogen bond interactions which is critical for transactivation. Natural mutant Ser46Phe in the core motif could likely led to conformational change resulting in more hydrogen bond interactions than the wild type Tat making it highly potent transactivator. Importantly, we report the possible probabilities of number of hydrogen bond interactions in the wild type Tat and the mutants with TAR complexes. This study revealed the differential transactivation of subtype B and C Tat could likely be due to the varying number of hydrogen bonds with TAR. Our data support that the N-terminal and the C-terminal domains of Tat is involved in the TAR interactions through hydrogen bonds which is important for transactivation. This study highlights the evolving pattern of structurally important determinants of Tat in the arginine motif for viral transactivation.

  5. The Holocene evolution of the beach and inland aeolian sand of the north-central Mediterranean coast of Israel

    Science.gov (United States)

    Roskin, Joel; Sivan, Dorit; Bookman, Revital; Shteinberg, Gilad

    2015-04-01

    Israel's coastal geomorphology, situated within a Mediterranean climate zone, is characterized by parallel Pleistocene aeolianite ridges, coastal cliffs of aeolianite, and sandy beaches. Lobe-like fields of predominantly stable transverse and parabolic quartz sand dunes protrude 2-7 km inland from the current Mediterranean Sea coastline. However, their migration and accumulation history is still not well-defined. This study focuses on the Holocene appearance, chronology and drivers of beach sand deposition and inland aeolian sand transport along the Caesarea-Hadera dunefield in the north-central coastal plain of Israel. In order to achieve these goals, a detailed field survey and sampling campaign was carried out along a west-east and southwest-northeast transect, loyal to the advancement orientations of the currently stable dunes and directions of dominant sand transporting winds. Beach sand, a foredune, a linear dune, and interdunes of parabolic and transverse dunes were sampled down to their aeolianite or red loam (locally named hamra) palaeosol substrate by drilling and analyzing exposed sections. The sampled sediments were sedimentologically analyzed and twenty-five were dated by optically stimulated luminescence (OSL). The results indicate that beach sand started to accumulate rapidly around 6 ka probably in response to global sea level stabilization. Until around 4 ka, thin sand sheets encroached 2-3 km inland. Sand ages in the range of 1.2-1.1 ka (8th-9th century CE -- Early Moslem period) were found throughout the study area, suggesting a major mobilization of sand, followed by stabilization around 0.6 ka and pedogenesis. By 1.2 ka, the sands had reached their current extent of 5-7 km inland, suggesting transport in a southwest-northeast orientation similar to the advancement orientation of the current transverse and parabolic dunes. The particle-size distributions of the fine to medium-sized aeolian sand showed minor variation linked to inland transport

  6. Crest line minimal model for sand dune

    OpenAIRE

    Guignier, Lucie; Valance, Alexandre; Lague, Dimitri

    2013-01-01

    International audience; In desert, complex patterns of dunes form. Under unidirectional wind, transverse rectilinear dunes or crescent shaped dunes called barchan dunes can appear, depending on the amount of sediment available. Most rectilinear transverse sand dunes are observed to fragment, for example at White Sands (New Mexico, United States of America) or Walvis Bay (Namibia). We develop a reduced complexity model to investigate the morphodynamics of sand dunes migrating over a non-erodib...

  7. Potential contributions of asphalt and coal tar to black carbon quantification in urban dust, soils, and sediments

    Science.gov (United States)

    Yang, Y.; Mahler, B.J.; Van Metre, P.C.; Ligouis, B.; Werth, C.J.

    2010-01-01

    Measurements of black carbon (BC) using either chemical or thermal oxidation methods are generally thought to indicate the amount of char and/or soot present in a sample. In urban environments, however, asphalt and coal-tar particles worn from pavement are ubiquitous and, because of their pyrogenic origin, could contribute to measurements of BC. Here we explored the effect of the presence of asphalt and coal-tar particles on the quantification of BC in a range of urban environmental sample types, and evaluated biases in the different methods used for quantifying BC. Samples evaluated were pavement dust, residential and commercial area soils, lake sediments from a small urban watershed, and reference materials of asphalt and coal tar. Total BC was quantified using chemical treatment through acid dichromate (Cr2O7) oxidation and chemo-thermal oxidation at 375??C (CTO-375). BC species, including soot and char/charcoal, asphalt, and coal tar, were quantified with organic petrographic analysis. Comparison of results by the two oxidation methods and organic petrography indicates that both coal tar and asphalt contribute to BC quantified by Cr2O7 oxidation, and that coal tar contributes to BC quantified by CTO-375. These results are supported by treatment of asphalt and coal-tar reference samples with Cr2O7 oxidation and CTO-375. The reference asphalt is resistant to Cr2O7 oxidation but not to CTO-375, and the reference coal tar is resistant to both Cr2O7 oxidation and CTO-375. These results indicate that coal tar and/or asphalt can contribute to BC measurements in samples from urban areas using Cr2O7 oxidation or CTO-375, and caution is advised when interpreting BC measurements made with these methods. ?? 2010 Elsevier Ltd.

  8. 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.

  9. Central Asian sand seas climate change as inferred from OSL dating

    Science.gov (United States)

    Maman, Shimrit; Tsoar, Haim; Blumberg, Dan; Porat, Naomi

    2014-05-01

    Luminescence dating techniques have become more accessible, widespread, more accurate and support studies of climate change. Optically stimulated luminescence (OSL) is used to determine the time elapsed since quartz grains were last exposed to sunlight, before they were buried and the dune stabilized. Many sand seas have been dated extensively by luminescence, e.g., the Kalahari, Namib the Australian linear dunes and the northwestern Negev dune field, Israel. However, no ages were published so far from the central Asian sand seas. The lack of dune stratigraphy and numerical ages precluded any reliable assessment of the paleoclimatic significance of dunes in central Asia. Central Asian Sand seas (ergs) have accumulated in the Turan basin, north-west of the Hindu Kush range, and span from south Turkmenistan to the Syr-Darya River in Kazakhstan. These ergs are dissected by the Amu-Darya River; to its north lies the Kyzylkum (red sands) and to its south lies the Karakum (black sands). Combined, they form one of the largest sand seas in the world. This area is understudied, and little information has been published regarding the sands stabilization processes and deposition ages. In this study, OSL ages for the Karakum and Kyzylkum sands are presented and analysis of the implications of these results is provided. Optical dates obtained in this study are used to study the effects climatic changes had on the mobility and stability of the central Asian sand seas. Optically stimulated luminescence ages derived from the upper meter of the interdune of 14 exposed sections from both ergs, indicate extensive sand and dune stabilization during the mid-Holocene. This stabilization is understood to reflect a transition to a warmer, wetter, and less windy climate that generally persisted until today. The OSL ages, coupled with a compilation of regional paleoclimatic data, corroborate and reinforce the previously proposed Mid-Holocene Liavliakan phase, known to reflect a warmer

  10. Fresh tar (from biomass gasification) destruction with downstream catalysts: comparison of their intrinsic activity with a realistic kinetic model

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Complutense Univ. of Madrid (Spain). Dept. of Chemical Engineering

    1996-12-31

    A model for fresh tar destruction over catalysts placed downstream a biomass gasifier is presented. It includes the stoichio-metry and the calculation of the kinetic constants for the tar destruction. Catalysts studied include commercial Ni steam reforming catalysts and calcinated dolomites. Kinetic constants for tar destruction are calculated for several particle sizes, times- on-stream and temperatures of the catalyst and equivalence ratios in the gasifier. Such intrinsic kinetic constants allow a rigorous or scientific comparison of solids and conditions to be used in an advanced gasification process. (orig.) 4 refs.

  11. Characterization of the HIV-1 TAR RNA-Tat peptide and drug interactions by on-line acoustic wave sensor

    Science.gov (United States)

    Tassew, Nardos Gobena

    This thesis presents the application of the thickness shear-mode (TSM) acoustic wave sensor to the study of RNA-protein and RNA-drug interactions at the solid-liquid interface. The binding of the human immunodeficiency virus-type 1 Tat protein to the trans-activation responsive RNA element (TAR) has been studied using this sensor. Data from such measurements show that the sensor is able to discriminate between different Tat peptides derived from the parent protein based on size. The effects of mutations introduced at specific sites in the protein and RNA on the TAR-Tat binding have also been examined in detail. Reduced level of response in acoustic parameters due to mutations was observed indicating that the decrease in binding in response to site specific mutations can be acoustically detected. Data from acoustic wave sensor measurements indicate that the TAR-Tat binding is also affected by ionic strength. Both the frequency and motional resistance signals show periodic responses when varying concentrations of salt are introduced on a TAR-modified surface. The binding of the two molecules seems to be a function of the response of the nucleic acid to salt concentrations. The kinetics of binding of Tat peptides to TAR RNA and to a bulge mutant analogue (MTAR) is also examined from the rate of change of the series resonant frequency. Results from such analysis illustrate longer Tat peptides formed more stable complexes with TAR RNA and exhibited increased discrimination between mutant and wild type TAR. The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to TAR RNA and their effectiveness in preventing TAR-Tat complex formation has been studied in detail. Binding affinity is directly correlated with the inhibitory potency of these molecules and the TSM sensor shows that neomycin exhibits at least a ten fold greater affinity to TAR and that it is also a more potent inhibitor than streptomycin. The results from this research involving TAR-Tat and

  12. Microbial metabolism alters pore water chemistry and increases consolidation of oil sands tailings.

    Science.gov (United States)

    Arkell, Nicholas; Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-01-01

    Tailings produced during bitumen extraction from surface-mined oil sands ores (tar sands) comprise an aqueous suspension of clay particles that remain dispersed for decades in tailings ponds. Slow consolidation of the clays hinders water recovery for reuse and retards volume reduction, thereby increasing the environmental footprint of tailings ponds. We investigated mechanisms of tailings consolidation and revealed that indigenous anaerobic microorganisms altered porewater chemistry by producing CO and CH during metabolism of acetate added as a labile carbon amendment. Entrapped biogenic CO decreased tailings pH, thereby increasing calcium (Ca) and magnesium (Mg) cations and bicarbonate (HCO) concentrations in the porewater through dissolution of carbonate minerals. Soluble ions increased the porewater ionic strength, which, with higher exchangeable Ca and Mg, decreased the diffuse double layer of clays and increased consolidation of tailings compared with unamended tailings in which little microbial activity was observed. These results are relevant to effective tailings pond management strategies. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Simulating and understanding sand wave variation: a case study of the Golden Gate sand waves

    NARCIS (Netherlands)

    Sterlini-Van der Meer, Fenneke; Hulscher, Suzanne J.M.H.; Hanes, D.M

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the

  14. Seasonal persistence and population characteristics of Escherichia coli and entercocci in deep backshore sand of two freshwater beaches

    Science.gov (United States)

    Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Ting, W.T.E.; Tseng, C.C.; Nevers, M.B.

    2006-01-01

    We studied the shoreward and seasonal distribution of E. coli and enterococci in sand (at the water table) at two southern Lake Michigan beaches - Dunbar and West Beach (in Indiana). Deep, backshore sand (??? 20 m inland) was regularly sampled for 15 months during 2002-2003. E. coli counts were not significantly different in samples taken at 5-m intervals from 0-40 M inland (P = 0.25). Neither E. coli nor enterococci mean counts showed any correlation or differences between the two beaches studied. In laboratory experiments, E. coli readily grew in sand supplemented with lake plankton, suggesting that in situ E. coli growth may occur when temperature and natural organic sources are adequate. Of the 114 sand enterococci isolates tested, positive species identification was obtained for only 52 (46%), with E. faecium representing the most dominant species (92%). Genetic characterization by ribotyping revealed no distinct genotypic pattern (s) for E. coli, suggesting that the sand population was rather a mixture of numerous strains (genotypes). These findings indicate that E. coli and enterococci can occur and persist for extended periods in backshore sand at the groundwater table. Although this study was limited to two beaches of southern Lake Michigan, similar findings can be expected at other temperate freshwater beaches. The long-term persistence of these bacteria, perhaps independent of pollution events, complicates their use as indicator organisms. Further, backshore sand at the water table may act as a reservoir for these bacteria and potentially for human pathogens. ?? IWA Publishing 2006.

  15. Groundwater Remediation and Alternate Energy at White Sands Test Facility

    Science.gov (United States)

    Fischer, Holger

    2008-01-01

    White Sands Test Facility Core Capabilities: a) Remote Hazardous Testing of Reactive, Explosive, and Toxic Materials and Fluids; b) Hypergolic Fluids Materials and Systems Testing; c) Oxygen Materials and System Testing; d) Hypervelocity Impact Testing; e)Flight Hardware Processing; and e) Propulsion Testing. There is no impact to any drinking water well. Includes public wells and the NASA supply well. There is no public exposure. Groundwater is several hundred feet below ground. No air or surface water exposure. Plume is moving very slowly to the west. Plume Front Treatment system will stop this westward movement. NASA performs on-going monitoring. More than 200 wells and zones are routinely sampled. Approx. 850 samples are obtained monthly and analyzed for over 300 different hazardous chemicals.

  16. 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.

  17. 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

  18. 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...

  19. Silica sand resources in the Netherlands

    NARCIS (Netherlands)

    Meulen, M.J. van der; Westerhoff, W.E.; Menkovic, A.; Gruijters, S.H.L.L.; Dubelaar, C.W.; Maljers, D.

    2009-01-01

    Silica sand, (almost) pure quartz sand, is a valuable and scarce mineral resource within the shallow Dutch subsurface. High-grade deposits are exploited in the southeastemmost part of the country, as raw material for the glass, ceramic, chemical and other process industries. Dutch land-use policy

  20. Excerpt of the Interview with Mathew Sands

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 9. Excerpt of the Interview with Mathew Sands. Mathew Sands Finn Aaserud. Face to Face Volume 16 Issue 9 September 2011 pp 881-885. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. 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 ...

  2. Review of Sand Production Prediction Models

    Directory of Open Access Journals (Sweden)

    Hossein Rahmati

    2013-01-01

    Full Text Available Sand production in oil and gas wells can occur if fluid flow exceeds a certain threshold governed by factors such as consistency of the reservoir rock, stress state and the type of completion used around the well. The amount of solids can be less than a few grams per cubic meter of reservoir fluid, posing only minor problems, or a substantial amount over a short period of time, resulting in erosion and in some cases filling and blocking of the wellbore. This paper provides a review of selected approaches and models that have been developed for sanding prediction. Most of these models are based on the continuum assumption, while a few have recently been developed based on discrete element model. Some models are only capable of assessing the conditions that lead to the onset of sanding, while others are capable of making volumetric predictions. Some models use analytical formulae, particularly those for estimating the onset of sanding while others use numerical models, particularly in calculating sanding rate. Although major improvements have been achieved in the past decade, sanding tools are still unable to predict the sand mass and the rate of sanding for all field problems in a reliable form.

  3. Mineralization Of PAHs In Coal-Tar Impacted Aquifer Sediments And Associated Microbial Community Structure Investigated With FISH

    Science.gov (United States)

    The microbial community structure and mineralization of polycyclic aromatic hydrocarbons (PAHs) in a coal-tar contaminated aquifer were investigated spatially using fluorescence in situ hybridization (FISH) and in laboratory-scale incubations of the aquifer sediments. DAPI-detect...

  4. Genetic relationship of organic bases of the quinoline and isoquinoline series from lignite semicoking tars with the initial biological material

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Podshibyakin, S.I.; Domogatskii, V.V.; Shvykin, A.Y.; Shavyrina, O.A.; Chilachava, K.B. [Leo Tolstoy State Pedagog University, Tula (Russian Federation)

    2002-07-01

    The genetic relationship of quinoline and isoquinoline compounds present in semicoking tars of Kimovsk lignites (near-Moscow fields) with the initial vegetable material is discussed. Transformation pathways of the native compounds in the course of lignite formation are suggested.

  5. 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

  6. The Effect of Sand on Strength of Mixtures of Bentonite-Sand

    Science.gov (United States)

    Pakbaz, Mohammad C.; Khayat, Navid

    The main purpose of this research is to evaluate the effect of sand on strength of compacted samples of bentonite sand mixtures. Samples of bentonite with 10,30,50,70, and 80 percent by weight of sand at standard proctor optimum water content were compacted and tested to measure confined and unconfined strength. Unconfined strength of mixtures increased with percentage of sand until 50 percent and then it decreased thereafter. On the other hand, the confined strength of mixtures tested in triaxial UU increased with percentage of sand.

  7. Flowability in crushed sand mortar

    Directory of Open Access Journals (Sweden)

    Cabrera, O. A.

    2010-12-01

    Full Text Available The present experimental study explored the relationship between mortar flowability and the voids content in crushed sand to determine the effect of grain shape and surface texture as well as dust content on the behaviour of fresh mortar. The findings revealed a close correlation between voids content and the volume of paste needed for mortar to begin to flow as a continuous material, mortar flowability and the water content needed to attain a given flowability. The comparison of the empirical findings to the results obtained with the Larrard (1, 2 model provided further information on the effect of sand grain morphology on fresh mortars.

    En el presente trabajo se plantea un estudio experimental de la fluidez de morteros basado en el contenido de vacíos de arenas machacadas, para comprender la influencia de la forma y textura superficial de los granos de arena y del contenido de polvo de las mismas sobre el estado fresco de morteros. Los resultados muestran la estrecha relación entre el contenido de vacíos entre granos y los volúmenes de pasta necesarios para iniciar el escurrimiento como un material continuo, la fluidez de los morteros, el contenido de agua para alcanzar una determinada fluidez, etc. El comportamiento evaluado se compara con resultados obtenidos aplicando el modelo de F. de Larrard (1, 2, permitiendo de este modo obtener mayor información de la influencia de la morfología de los granos de la arena sobre el estado fresco de los morteros.

  8. Calcipotriol versus coal tar: a prospective randomized study in stable plaque psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, V.; Kaur, I.; Kumar, B. [Postgraduate Institute of Medicinal Education & Research, Chandigarh (India)

    2003-10-01

    Topical therapies are the first line of treatment for patients with stable plaque psoriasis (SPP) affecting a limited body surface area. Very few trials comparing newer agents, such as 0.005% topical calcipotriol, with conventional modes of therapy, such as coal tar ointment, have been reported. A prospective, right-left randomized, investigator-blinded study with a 12-week treatment period and an 8-week follow-up period was performed. It was found that 0.005% calcipotriol ointment produced a faster initial response and had better cosmetic acceptability in patients, although after a long period of treatment, i.e. 12 weeks, 5% coal tar ointment had comparable efficacy. There was no statistically significant difference in the relapse rates between the two modalities.

  9. The TAR model: use of therapeutic state transitions for quality assurance reporting in chronic disease management.

    Science.gov (United States)

    Gaikwad, R; Warren, J; Kenealy, T

    2007-01-01

    Chronic disease management represents one of the challenges for health informatics and demands the appropriate application of information technology for improved patient care. This paper presents an approach to quality assurance reporting wherein the recommendations of evidence-based clinical practice guidelines are considered in the context of empirical therapeutic state-transitions (in terms of changes in individual patient prescriptions over time). We apply a Transition-based Audit Report (TAR) model to antihypertensive prescribing and related data as stored in a New Zealand General Practice Management System database. The results provide a set of quality indicators and specific patient cohorts for potential practice quality improvement with strong linkage to the selected guidelines and observed practice patterns. We see the TAR model primarily as a tool to enable internal quality improvement efforts, but also to be of relevance for focusing pay-for-performance programs.

  10. A proteomic study of TAR-RNA binding protein (TRBP-associated factors

    Directory of Open Access Journals (Sweden)

    Chi Ya-Hui

    2011-02-01

    Full Text Available Abstract Background The human TAR RNA-binding protein, TRBP, was first identified and cloned based on its high affinity binding to the small hairpin trans-activation responsive (TAR RNA of HIV-1. TRBP has more recently been found to be a constituent of the RNA-induced silencing complex (RISC serving as a Dicer co-factor in the processing of the ~70 nucleotide pre-microRNAs(miRNAs to 21-25 nucleotide mature miRNAs. Findings Using co-immunoprecipitation and protein-identification by mass spectrometry, we characterized intracellular proteins that complex with TRBP. These interacting proteins include those that have been described to act in protein synthesis, RNA modifications and processing, DNA transcription, and cell proliferation. Conclusions Our findings provide a proteome of factors that may cooperate with TRBP in activities such as miRNA processing and in RNA interference by the RISC complex.

  11. Gasification of biomass in a fixed bed downdraft gasifier--a realistic model including tar.

    Science.gov (United States)

    Barman, Niladri Sekhar; Ghosh, Sudip; De, Sudipta

    2012-03-01

    This study presents a model for fixed bed downdraft biomass gasifiers considering tar also as one of the gasification products. A representative tar composition along with its mole fractions, as available in the literature was used as an input parameter within the model. The study used an equilibrium approach for the applicable gasification reactions and also considered possible deviations from equilibrium to further upgrade the equilibrium model to validate a range of reported experimental results. Heat balance was applied to predict the gasification temperature and the predicted values were compared with reported results in literature. A comparative study was made with some reference models available in the literature and also with experimental results reported in the literature. Finally a predicted variation of performance of the gasifier by this validated model for different air-fuel ratio and moisture content was also discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Formulation of Pine Tar Antidandruff Shampoo Assessment and Comparison With Some Commercial Formulations

    Directory of Open Access Journals (Sweden)

    M. Gharavi

    1990-07-01

    Full Text Available In this study a pine tar shampoo as a new antidandruff formulation is presented. Assessment of antidandruff preparations has been hampered by the lack of standardized schedules, and reliable methods of evaluation.Some antidandruff agents such as : Zinc pyri-thione pine tar, selenium sulphide and (sulfure were used in shampoos. Samples were coded as numbers 1,2 formulated by us and 3,4 formulated commercially. The grading scheme based on 10 point scale, and corneocyte count was carried out on 50 selected volunte¬ers. Corneocyte count and fungal study proved that pine tor shampoo is effective against pityrosporum ovale. Draize lest was used for determination of the irritancy potential of the samples. Results showed that samples numbered 1,2 were relatively innocous in comparison with the others. I urthermore,s kin sensitination test on rabbit also confirmed the results obtained by Draize test. Consumer judgments proved that all formulations were acceptable.

  13. Development of Catalytic Tar Decomposition in an Internally Circulating Fluidized-Bed Gasifier

    Science.gov (United States)

    Xiao, Xianbin; Le, Due Dung; Morishita, Kayoko; Li, Liuyun; Takarada, Takayuki

    Biomass gasification in an Internally Circulating Fluidized-bed Gasifier (ICFG) using Ni/Ah03 as tar cracking catalyst is studied at low temperature. Reaction conditions of the catalyst bed are discussed, including catalytic temperature and steam ratio. High energy efficiency and hydrogen-rich, low-tar product gas can be achieved in a properly designed multi-stage gasification process, together with high-performance catalyst. In addition, considering the economical feasibility, a newly-developed Ni-loaded brown coal char is developed and evaluated as catalyst in a lab-scale fluidized bed gasifier with catalyst fixed bed. The new catalyst shows a good ability and a hopeful prospect oftar decomposition, gas quality improvement and catalytic stability.

  14. Coal-tar pavement sealants might substantially increase children's PAH exposures

    Science.gov (United States)

    Williams, E. Spencer; Mahler, Barbara J.; Van Metre, Peter C.

    2012-01-01

    Dietary ingestion has been identified repeatedly as the primary route of human exposure to polycyclic aromatic hydrocarbons (PAHs), seven of which are classified as probable human carcinogens (B2 PAHs) by the U.S. EPA. Humans are exposed to PAHs through ingestion of cooked and uncooked foods, incidental ingestion of soil and dust, inhalation of ambient air, and absorption through skin. Although PAH sources are ubiquitous in the environment, one recently identified PAH source stands out: Coal-tar-based pavement sealant—a product applied to many parking lots, driveways, and even playgrounds primarily in the central, southern, and eastern U.S.—has PAH concentrations 100–1000 times greater than most other PAH sources. It was reported recently that PAH concentrations in house dust in residences adjacent to parking lots with coal-tar-based sealant were 25 times higher than in residences adjacent to unsealed asphalt parking lots.

  15. Preserving inland drift sands in the Netherlands

    Science.gov (United States)

    Riksen, M.; Sparrius, L.; Nijssen, M.; Keestra, S.

    2012-04-01

    Inland drift sands in the Netherlands are an important landscape type within the Dutch nature. They represent an important pioneer habitat which has become rare in European nature. Under current climate and environmental conditions (i.e. high N-deposition) these inland drift sands tend to be rapid colonialized by vegetation and therefor lose their aeolian activity. To maintain the area bare sand, managers regularly remove the vegetation. Lack of proper knowledge about the geomorphological processes and even more important on the geomorphological structure of these drift sands, could lead to the loss of characteristic dune structure. In an interdisciplinary research project a new management strategy was developed in which the geomorphological processes and structure form the base for the planning process. To improve the awareness of these aspects among nature managers we developed a management tool "PROMME". Several activities were taken to communicate this with the people involved in the management of drift sands like a brochure and field workshops.

  16. Ecological release in White Sands lizards.

    Science.gov (United States)

    Roches, S Des; Robertson, J M; Harmon, L J; Rosenblum, E B

    2011-12-01

    Ecological opportunity is any change that allows populations to escape selection from competition and predation. After encountering ecological opportunity, populations may experience ecological release: enlarged population size, broadened resource use, and/or increased morphological variation. We identified ecological opportunity and tested for ecological release in three lizard colonists of White Sands, New Mexico (Sceloporus undulatus, Holbrookia maculata, and Aspidoscelis inornata). First, we provide evidence for ecological opportunity by demonstrating reduced species richness and abundance of potential competitors and predators at White Sands relative to nearby dark soils habitats. Second, we characterize ecological release at White Sands by demonstrating density compensation in the three White Sands lizard species and expanded resource use in White Sands S. undulatus. Contrary to predictions from ecological release models, we observed directional trait change but not increased trait variation in S. undulatus. Our results suggest that ecological opportunity and ecological release can be identified in natural populations, especially those that have recently colonized isolated ecosystems.

  17. Choosing an optimum sand control method

    Directory of Open Access Journals (Sweden)

    Ehsan Khamehchi

    2015-06-01

    Full Text Available Formation sand control is always one of the main concerns of production engineers. There are some different methods to prevent sand production. Choosing a method for preventing formation sand production depends on different reservoir parameters and politic and economic conditions. Sometimes, economic and politic conditions are more effective to choose an optimum than reservoir parameters. Often, simultaneous investigation of politic and economic conditions with reservoir parameters has different results with what is expected. So, choosing the best sand control method is the result of thorough study. Global oil price, duration of sand control project and costs of necessary equipment for each method as economic and politic conditions and well productivity index as reservoir parameter are the main parameters studied in this paper.

  18. Ecological release in White Sands lizards

    Science.gov (United States)

    Roches, S Des; Robertson, J M; Harmon, L J; Rosenblum, E B

    2011-01-01

    Ecological opportunity is any change that allows populations to escape selection from competition and predation. After encountering ecological opportunity, populations may experience ecological release: enlarged population size, broadened resource use, and/or increased morphological variation. We identified ecological opportunity and tested for ecological release in three lizard colonists of White Sands, New Mexico (Sceloporus undulatus, Holbrookia maculata, and Aspidoscelis inornata). First, we provide evidence for ecological opportunity by demonstrating reduced species richness and abundance of potential competitors and predators at White Sands relative to nearby dark soils habitats. Second, we characterize ecological release at White Sands by demonstrating density compensation in the three White Sands lizard species and expanded resource use in White Sands S. undulatus. Contrary to predictions from ecological release models, we observed directional trait change but not increased trait variation in S. undulatus. Our results suggest that ecological opportunity and ecological release can be identified in natural populations, especially those that have recently colonized isolated ecosystems. PMID:22393523

  19. Topical coal tar alone and in combination with oral methotrexate in management of psoriasis : a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Prasad PVS

    1997-01-01

    Full Text Available Thirty five patients admitted with psoriasis were analysed. 16 patients received 20% crude coal tar and 19 patients received 20% crude coal tar along with methotrexate in a weekly oral schedule (15mg/wk. After 4 weeks of therapy there was total clearence in 52.6% of the patients with combination therapy, whereas only 12.5% of the patients with conventional therapy achieved this.

  20. OLGA. Flexible tar removal for high efficient production of clean heat and power as well as sustainable fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Zwart, R.W.R. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

    2009-09-15

    The content of the paper lists the following subjects: The tar problem; The OLGA technology; The development with Step 1: Demonstration of high-efficient production of clean heat and power, Step 2: Developing high-efficient production of sustainable fuels and chemicals, and Step 3: Demonstrating the flexibility of the OLGA tar removal technology. Further, attention is paid to Commercial gasification projects, and finally Conclusions are formulated and an Outlook is given.

  1. Search for a solvent using the UNIFAC method for separation of coal tar distillate by liquid-liquid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Egashira, R.; Watanabe, K. [Tokyo Institute of Technology, Tokyo (Japan)

    2007-07-01

    Firstly, the functional groups composing the solvent predicted to be appropriate for the separation of coal tar distillate were selected. Secondly, liquid-liquid equilibria between coal tar distillates and solvents containing fictitious components consisting of the above selected functional groups were estimated by UNIFAC to determine the effects of these groups on the distribution coefficients. Finally, according to these results, solvents containing real components were selected and compared. These results provide useful information for the selection of appropriate extracting solvents.

  2. West Nile Virus

    Science.gov (United States)

    West Nile virus (WNV) is an infectious disease that first appeared in the United States in 1999. Infected mosquitoes ... and usually go away on their own. If West Nile virus enters the brain, however, it can be life- ...

  3. Remediation of Coal Tar by STAR: Self-Sustaining Propagation Across Clean Gaps

    Science.gov (United States)

    Gerhard, J.; Brown, J.; Torero, J. L.; Grant, G.

    2016-12-01

    Self-sustaining Treatment for Active Remediation (STAR) is an emerging remediation technique which utilizes a subsurface smouldering reaction to destroy non-aqueous phase liquids (NAPL) in situ. The reaction is self-sustaining in that, once ignited, the destructive smouldering front will propagate outwards using only the energy embedded in the contaminant. However, it is known that coal tar can occur as both a continuous pool as well as in distinct seams separated by clean intervals. This study evaluated the hypothesis that the smouldering reaction can cross or `jump' clean gaps by transferring enough heat through the gap to re-ignite the reaction in the contaminated region beyond. Column and 2D box experiments were performed at two scales to determine the maximum clean gap which could be jumped vertically and horizontally. Once the maximum gap had been determined, sensitivity to various in situ and engineering control parameters were explored including: coal tar layer thickness, soil permeability, moisture content, NAPL saturation, and air injection flowrate. High resolution thermocouples informed the progress of the reaction, continuous gas emissions analysis revealed when the reaction was active and dormant, and detailed excavation mapped the extent of remediation and whether gaps were successfully jumped. The work demonstrated that substantial clean gaps, approaching the limit of the laboratory scale, can be jumped by the smouldering reaction using convective heat transfer. Also observed in some cases was the mobilization of pre-heated coal tar into the clean gaps and the reaction's ability to propagate through and destroy coal tar both adjacent to and within the gaps. This work is providing new insights into the robust nature of the technology for in situ applications, and indicating how extreme the heterogeneity has to be before the reaction is interrupted and a new ignition location would be required.

  4. Effects of the chemical composition of coal tar pitch on dimensional changes during graphitization / Lay Shoko

    OpenAIRE

    Shoko, Lay

    2014-01-01

    Coal can be converted to different chemical products through processes such destructive distillation. The destructive distillation of coal yields coke as the main product with byproducts such as coal tar pitch (CTP). CTP has a wide range of applications, especially in the carbon-processing industries. Typical applications include the manufacture of anodes used in many electrochemical processes, as well as Söderberg electrodes used in different ferroalloy processes. Söderberg el...

  5. Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement.

    Science.gov (United States)

    Van Metre, Peter C; Majewski, Michael S; Mahler, Barbara J; Foreman, William T; Braun, Christopher L; Wilson, Jennifer T; Burbank, Teresa L

    2012-06-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (ΣPAH(8)) in the 0.03-m samples above sealed lots (1320 ng m(-3)) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m(-3)). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m(-3)) was five times greater than above unsealed lots (26.0 ng m(-3)). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 μg m(-2) h(-1), respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces. Published by Elsevier Ltd.

  6. Investigating Efficient Tar Management from Biomass and Waste to Energy Gasification Processes

    Science.gov (United States)

    2015-04-01

    breaks tars down completely to carbon monoxide and hydrogen and then combusts these molecules or uses them in liquid fuel production. Literature shows...Toluene, Xylene CFM Cubic Feet per Minute CO Carbon Monoxide CO2 Carbon Dioxide CONUS Continental US DoD Department of Defense...amounts of methanol and ethanol, which are all flammable liquids. A current manual for a COTS diesel genset allows 35% aromatic fuel in the mix. As a

  7. A SUMERIAN MUSICAL INSTRUMENT IN HITTITE CUNEIFORM DOCUMENTS: ( GIŠ )ŠÀ.A.TAR/ TIBULA

    OpenAIRE

    MASALCI ŞAHİN, Gülgüney

    2016-01-01

    The Hittites who provided a political unity in Anatolia circa 2000 BC, calledthemselves as "nation of thousand gods". They celebrated many festivals fortheir god's name and performed rituals. Music which is an important componentof the culture is the one of the essential elements of Hittite’s religious ceremonies.There were lots of musical instruments in cultic feasts, libations, celebrating festivalsand funerals. The common idea was aboutGIŠ ŠÀ.A.TAR/ TIBULA which wasit was a ...

  8. Steam reforming of tar model compound using Pd catalyst on alumina tube.

    Science.gov (United States)

    Nisamaneenate, Jurarat; Atong, Duangduen; Sricharoenchaikul, Viboon

    2012-12-01

    Gasification processing of biomass as a renewable energy source generates tar in the product gas. Tar leads to foul-up of the process equipment by corrosion and deposit formation. Catalytic elimination of tars is a crucial step to improve fuel gas quality from the process. In this study, a palladium catalyst on alumina (Pd/Al2O3) was used in steam reforming of benzene as a biomass gasification tar model compound. The reaction was carried out in a laboratory-scale tube reactor made of stainless steel to study the effect of reaction temperature, catalyst loading, quantity of palladium catalyst tubes, steam to carbon ratio (S/C), and residence time on catalytic performance and stability. Pd/Al2O3 showed high efficiency ofbenzene decomposition and enhanced the formation of fuel gas. Hydrogen and carbon conversions increased with reaction temperature. Although the benzene concentration increased from 2000 to 5000 mg/l, the catalytic performance at 600 degrees C and 800 degrees C was similar. 1.0 wt% Pd/Al2O3 showed excellent catalytic activity with the highest hydrogen and carbon conversions of 83% and 81%, respectively at 800 degrees C. This result is attributed to the smooth surface of the palladium, as noted from scanning electron microscopy imaging. An S/C of 2 provided the highest conversion. The addition of catalyst from four and seven tubes did not result in any great difference in terms of benzene cracking efficiency. The fourth cyclic usage of 1.0 wt% Pd/Al2O3 exhibited a higher conversion than that of 0.5 wt%.

  9. Preparation and Characterization of Malaysian Dolomites as a Tar Cracking Catalyst in Biomass Gasification Process

    OpenAIRE

    M. A. A. Mohammed; A. Salmiaton; W. A. K. G. Wan Azlina; M. S. Mohamad Amran; Y. H. Taufiq-Yap

    2013-01-01

    Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites u...

  10. Sequence and structure requirements for specific recognition of HIV-1 TAR and DIS RNA by the HIV-1 Vif protein.

    Science.gov (United States)

    Freisz, Séverine; Mezher, Joelle; Hafirassou, Lamine; Wolff, Philippe; Nominé, Yves; Romier, Christophe; Dumas, Philippe; Ennifar, Eric

    2012-07-01

    The HIV-1 Vif protein plays an essential role in the regulation of the infectivity of HIV-1 virion and in vivo pathogenesis. Vif neutralizes the human DNA-editing enzyme APOBEC3 protein, an antiretroviral cellular factor from the innate immune system, allowing the virus to escape the host defence system. It was shown that Vif is packaged into viral particles through specific interactions with the viral genomic RNA. Conserved and structured sequences from the 5'-noncoding region, such as the Tat-responsive element (TAR) or the genomic RNA dimerization initiation site (DIS), are primary binding sites for Vif. In the present study we used isothermal titration calorimetry to investigate sequence and structure determinants important for Vif binding to short viral RNA corresponding to TAR and DIS stem-loops. We showed that Vif specifically binds TAR and DIS in the low nanomolar range. In addition, Vif primarily binds the TAR UCU bulge, but not the apical loop. Determinants for Vif binding to the DIS loop-loop complex are likely more complex and involve the self-complementary loop together with the upper part of the stem. These results suggest that Tat-TAR inhibitors or DIS small molecule binders might be also effective to disturb Vif-TAR and Vif-DIS binding in order to reduce Vif packaging into virions.

  11. Field and Model Study to Define Baseline Conditions of Beached Oil Tar Balls along Florida’s First Coast

    Directory of Open Access Journals (Sweden)

    Peter Bacopoulos

    2014-03-01

    Full Text Available Anecdotal data are currently the best data available to describe baseline conditions of beached oil tar balls on Florida’s First Coast beaches. This study combines field methods and numerical modeling to define a data-driven knowledge base of oil tar ball baseline conditions. Outcomes from the field study include an established methodology for field data collection and laboratory testing of beached oil tar balls, spatial maps of collected samples and analysis of the data as to transport/wash-up trends. Archives of the electronic data, including GPS locations and other informational tags, and collected samples are presented, as are the physical and chemical analyses of the collected samples. The thrust of the physical and chemical analyses is to differentiate the collected samples into highly suspect oil tar balls versus false/non-oil tar ball samples. The numerical modeling involves two-dimensional hydrodynamic simulations of astronomic tides. Results from the numerical modeling include velocity residuals that show ebb-dominated residual currents exiting the inlet via an offshore, counter-rotating dual-eddy system. The tidally derived residual currents are used as one explanation for the observed transport trends. The study concludes that the port activity in the St. Johns River is not majorly contributing to the baseline conditions of oil tar ball wash-up on Florida’s First Coast beaches.

  12. Marketing 'less harmful, low-tar' cigarettes is a key strategy of the industry to counter tobacco control in China.

    Science.gov (United States)

    Yang, Gonghuan

    2014-03-01

    While the 'low-tar' scheme has been widely recognised as a misleading tactic used by the tobacco industry to deceive the public about the true risks of cigarette smoking, a similar campaign using the slogan of 'less harmful, low tar' was launched by the Chinese tobacco industry, that is, State Tobacco Monopoly Administration/China National Tobacco Corporation and began to gain traction during the last decade. Despite the fact that no sufficient research evidence supports the claims made by the industry that these cigarettes are safer, the Chinese tobacco industry has continued to promote them using various health claims. As a result, the production and sales of 'less harmful, low-tar' cigarettes have increased dramatically since 2000. Recently, a tobacco industry senior researcher, whose main research area is 'less harmful, low-tar' cigarettes, was elected as an Academician to the prestigious Chinese Academy of Engineering for his contribution to developing 'less harmful, low-tar' cigarettes. The tobacco researcher's election caused an outcry from the tobacco control community and the general public in China. This paper discusses the Chinese tobacco industry's 'less harmful, low-tar' initiatives and calls for the Chinese government to stop the execution of this deceptive strategy for tobacco marketing.

  13. Effect of tar impregnation on carbon monoxide disintegration resistance in refractory lining of torpedo ladle

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Y.T.; Ko, Y.C.

    1982-07-01

    Investigates whether the Ludwig-Sorret effect could be used to cope with the lining disintegration caused by the deposition of carbon from carbon monoxide in torpedo ladles by impregnating with tar the aluminosilicate refractory brick which are not immune to carbon monoxide attack. Explains, on the basis of Ludwig-Sorret effect, that fluids diffuse from a region of higher temperature to that of lower temperature under the driving force of a temperature gradient; tar impregnated in torpedo ladle lining will flow toward the cold end during preheating and in service. Finds that the nondisintegration portion of the specimen contained neither carbon nor iron oxide-like substance. X-ray diffraction proved that an ironoxide-like substance, collected from the sites where carbon deposited, contained hematite and magnetite. Microscopic examination indicated that most residual carbon was found in the fine pores in the matrix. Concludes that it seems unlikely that tar impregnation for refractory brick that are not immune to carbon monoxide disintegration can significantly improve the disintegration resistance in torpedo ladles in service.

  14. Macroseepage of Methane and Light Alkanes at the La Brea Tar Pits in Los Angeles

    Science.gov (United States)

    Doezema, L. A.; Weber, D.; Schuffels, S.; Marquez, A.; Taylor, C.; Raya, P.; Howard, D.; Contreras, P.; Fusco, K.; Morales, F.; Nwachuku, I.

    2015-12-01

    Natural seepage of methane has been theorized to be an underreported source of global methane. Recent studies have also suggested that light alkane flux that is given off in combination with the methane also is underreported in local and global budgets. This study investigated macroseepage, visible seepage, at the La Brea Tar Pits in Los Angeles, CA. More than 100 samples were collected from individual seeps using stainless steel flux chambers and canisters and were analyzed for methane and C2-C5 alkanes using gas chromatography equipped with flame ionization detectors (GC-FID). Maximum hourly fluxes from individual seeps were over 70 g of methane and over 720 mg, 670 mg, 200 mg, 20 mg, 14 mg, and 0.2 mg for ethane, propane, i-butane, n-butane, i-pentane, and n-pentane respectively. In addition to the active seepage sites, a significant amount of methane and light alkanes was also found to come from outgassing from standing tar deposits. Using gas ratios found in this study along with overall methane emission estimates from another recent study, the La Brea Tar Pits were found to be a significant source of light alkanes in the South Coast Air Basin, contributing approximately 2% towards the overall budget.

  15. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States.

    Science.gov (United States)

    Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer T

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dustfrom coal-tarsealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted.

  16. Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement.

    Science.gov (United States)

    Williams, E Spencer; Mahler, Barbara J; Van Metre, Peter C

    2013-01-15

    Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10(-4), as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10(-5). Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0-6 years of age).

  17. Fast microwave-assisted catalytic gasification of biomass for syngas production and tar removal.

    Science.gov (United States)

    Xie, Qinglong; Borges, Fernanda Cabral; Cheng, Yanling; Wan, Yiqin; Li, Yun; Lin, Xiangyang; Liu, Yuhuan; Hussain, Fida; Chen, Paul; Ruan, Roger

    2014-03-01

    In the present study, a microwave-assisted biomass gasification system was developed for syngas production. Three catalysts including Fe, Co and Ni with Al2O3 support were examined and compared for their effects on syngas production and tar removal. Experimental results showed that microwave is an effective heating method for biomass gasification. Ni/Al2O3 was found to be the most effective catalyst for syngas production and tar removal. The gas yield reached above 80% and the composition of tar was the simplest when Ni/Al2O3 catalyst was used. The optimal ratio of catalyst to biomass was determined to be 1:5-1:3. The addition of steam was found to be able to improve the gas production and syngas quality. Results of XRD analyses demonstrated that Ni/Al2O3 catalyst has good stability during gasification process. Finally, a new concept of microwave-assisted dual fluidized bed gasifier was put forward for the first time in this study. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Inhibition of HIV Replication by Cyclic and Hairpin PNAs Targeting the HIV-1 TAR RNA Loop

    Directory of Open Access Journals (Sweden)

    Gregory Upert

    2012-01-01

    Full Text Available Human immunodeficiency virus-1 (HIV-1 replication and gene expression entails specific interaction of the viral protein Tat with its transactivation responsive element (TAR, to form a highly stable stem-bulge-loop structure. Previously, we described triphenylphosphonium (TPP cation-based vectors that efficiently deliver nucleotide analogs (PNAs into the cytoplasm of cells. In particular, we showed that the TPP conjugate of a linear 16-mer PNA targeting the apical stem-loop region of TAR impedes Tat-mediated transactivation of the HIV-1 LTR in vitro and also in cell culture systems. In this communication, we conjugated TPP to cyclic and hairpin PNAs targeting the loop region of HIV-1 TAR and evaluated their antiviral efficacy in a cell culture system. We found that TPP-cyclic PNAs containing only 8 residues, showed higher antiviral potency compared to hairpin PNAs of 12 or 16 residues. We further noted that the TPP-conjugates of the 8-mer cyclic PNA as well as the 16-mer linear PNA displayed similar antiviral efficacy. However, cyclic PNAs were shown to be highly specific to their target sequences. This communication emphasizes on the importance of small constrained cyclic PNAs over both linear and hairpin structures for targeting biologically relevant RNA hairpins.

  19. Aggravated test of Intermediate temperature solid oxide fuel cells fed with tar-contaminated syngas

    Science.gov (United States)

    Pumiglia, Davide; Vaccaro, Simone; Masi, Andrea; McPhail, Stephen J.; Falconieri, Mauro; Gagliardi, Serena; Della Seta, Livia; Carlini, Maurizio

    2017-02-01

    In the present work, the effects of a tar-containing simulated syngas on an IT-SOFC (Intermediate Temperature Solid Oxide Fuel Cell) are evaluated. Performance and degradation rate of a planar anode-supported cell, operating under a simulated syngas obtained from steam-enriched air gasification of biomass, have been studied. The simulated syngas was contaminated using toluene as a model tar. Polarization curves and electrochemical impedance spectroscopy have been carried out under different toluene concentrations. A cell was then operated under a constant current density on a long run. EIS measurements were made during the operation to analyze the degradation, and the voltage evolution of the cell was compared to that obtained from another identical cell operated in clean syngas for 1000 h under similar conditions. A deep post-mortem characterization was performed by means of XRD measurements, Raman spectroscopy and SEM/EDS analysis. Results show that the presence of tar dramatically reduces the electrochemical performances of the cell, affecting both activation and mass transport processes. Post-mortem analysis shows the formation of carbon deposits, oxidation of Ni to NiO, segregation of ZrO2 from the YSZ phase, particle coarsening and enhanced fragility of the anode structure, in good agreement with what suggested from the electrochemical results.

  20. Screening method for solvent selection used in tar removal by the absorption process.

    Science.gov (United States)

    Masurel, Eve; Authier, Olivier; Castel, Christophe; Roizard, Christine

    2015-01-01

    The aim of this paper is the study of the treatment of flue gas issued from a process of biomass gasification in fluidized bed. The flue gas contains tar which should be selectively removed from the fuel components of interest (e.g. H2, CO and light hydrocarbons) to avoid condensation and deposits in internal combustion engine. The chosen flue gas treatment is the gas-liquid absorption using solvents, which present specific physicochemical properties (e.g. solubility, viscosity, volatility and chemical and thermal stability) in order to optimize the unit on energetic, technico-economic and environmental criteria. The rational choice of the proper solvent is essential for solving the tar issue. The preselection of the solvents is made using a Hansen parameter in order to evaluate the tar solubility and the saturation vapour pressure of the solvent is obtained using Antoine law. Among the nine families of screened solvents (alcohols, amines, ketones, halogenates, ethers, esters, hydrocarbons, sulphured and chlorinates), acids methyl esters arise as solvents of interest. Methyl oleate has then been selected and studied furthermore. Experimental liquid-vapour equilibrium data using bubbling point and absorption cell measurements and theoretical results obtained by the UNIFAC-Dortmund model confirm the high potential of this solvent and the good agreement between experimental and theoretical results.

  1. Global sand trade is paving the way for a tragedy of the sand commons

    Science.gov (United States)

    Torres, A.; Brandt, J.; Lear, K.; Liu, J.

    2016-12-01

    In the first 40 years of the 21st century, planet Earth is highly likely to experience more urban land expansion than in all of history, an increase in transportation infrastructure by more than a third, and a great variety of land reclamation projects. While scientists are beginning to quantify the deep imprint of human infrastructure on biodiversity at large scales, its off-site impacts and linkages to sand mining and trade have been largely ignored. Sand is the most widely used building material in the world. With an ever-increasing demand for this resource, sand is being extracted at rates that far exceed its replenishment, and is becoming increasingly scarce. This has already led to conflicts around the world and will likely lead to a "tragedy of the sand commons" if sustainable sand mining and trade cannot be achieved. We investigate the environmental and socioeconomic interactions over large distances (telecouplings) of infrastructure development and sand mining and trade across diverse systems through transdisciplinary research and the recently proposed telecoupling framework. Our research is generating a thorough understanding of the telecouplings driven by an increasing demand for sand. In particular, we address three main research questions: 1) Where are the conflicts related to sand mining occurring?; 2) What are the major "sending" and "receiving" systems of sand?; and 3) What are the main components (e.g. causes, effects, agents, etc.) of telecoupled systems involving sand mining and trade? Our results highlight the role of global sand trade as a driver of environmental degradation that threatens the integrity of natural systems and their capacity to deliver key ecosystem services. In addition, infrastructure development and sand mining and trade have important implications for other sustainability challenges such as over-fishing and global warming. This knowledge will help to identify opportunities and tools to better promote a more sustainable use

  2. What's West Nile Virus?

    Science.gov (United States)

    ... OK for Kids? Your Teeth Heart Murmurs What's West Nile Virus? KidsHealth > For Kids > What's West Nile Virus? Print A A A en español ¿Qué es ... Virus del Nilo Occidental? What exactly is the West Nile virus? And why is everyone talking about mosquitoes ? Even ...

  3. MultiMiTar: a novel multi objective optimization based miRNA-target prediction method.

    Directory of Open Access Journals (Sweden)

    Ramkrishna Mitra

    Full Text Available BACKGROUND: Machine learning based miRNA-target prediction algorithms often fail to obtain a balanced prediction accuracy in terms of both sensitivity and specificity due to lack of the gold standard of negative examples, miRNA-targeting site context specific relevant features and efficient feature selection process. Moreover, all the sequence, structure and machine learning based algorithms are unable to distribute the true positive predictions preferentially at the top of the ranked list; hence the algorithms become unreliable to the biologists. In addition, these algorithms fail to obtain considerable combination of precision and recall for the target transcripts that are translationally repressed at protein level. METHODOLOGY/PRINCIPAL FINDING: In the proposed article, we introduce an efficient miRNA-target prediction system MultiMiTar, a Support Vector Machine (SVM based classifier integrated with a multiobjective metaheuristic based feature selection technique. The robust performance of the proposed method is mainly the result of using high quality negative examples and selection of biologically relevant miRNA-targeting site context specific features. The features are selected by using a novel feature selection technique AMOSA-SVM, that integrates the multi objective optimization technique Archived Multi-Objective Simulated Annealing (AMOSA and SVM. CONCLUSIONS/SIGNIFICANCE: MultiMiTar is found to achieve much higher Matthew's correlation coefficient (MCC of 0.583 and average class-wise accuracy (ACA of 0.8 compared to the others target prediction methods for a completely independent test data set. The obtained MCC and ACA values of these algorithms range from -0.269 to 0.155 and 0.321 to 0.582, respectively. Moreover, it shows a more balanced result in terms of precision and sensitivity (recall for the translationally repressed data set as compared to all the other existing methods. An important aspect is that the true positive

  4. Scaling laws in sand launch process

    Science.gov (United States)

    Min, Li; Yang, Zhang

    2017-04-01

    As the bond linking the micro research to the macro research in wind-sand flow, the scaling laws on sand mean launch velocity and mean launch angle can be used to calculate the mean velocity and the transport rate, and they also play an important role in understanding saltation. However, universal scaling laws are still absent. In analogy to the fluid flows, the wind-sand flow is divided into three periods based on the way of sand taking off from sand bed, and the hypothesis on the scaling laws in each period is proposed. Then according to the hypothesis we deduce the sand concentration piece-wise function for saltation layer and also the critical shields numbers dividing three periods. The comparisons between the predictions and the experimental observations show that under a lower shields number the vertical mean launch velocity and the mean launch angle scale with the wind shear velocity and the square root of shields number respectively. However, under a higher shields number the vertical mean launch velocity scale with the sand diameter and the mean launch angle is almost constant at 700 or so.

  5. The Influence of Sand Grains Properties on Electrical Properties of Moulding Sand with Inorganic Binder

    Directory of Open Access Journals (Sweden)

    Opyd B.

    2015-09-01

    Full Text Available The paper presents the results of basic research on the influence of the properties of sand grains on electrical properties of water glass moulding sands. It shows electrical properties of the main component – sand grains, crucial to the kinetics of moulding sands heating, such as permittivity εr and loss factor tgδ. Measurements were carried out with the use of the perturbation method for silica, chromite and olivine sands of different mineral, chemical composition and particle size distribution, as well as for moulding sands with water glass grade 145. Analysis of the results of measurements of electrical properties shows that all moulding sands are characterized by a similar permittivity εr and loss factor tgδ. It was found that the electrical properties and the quantity and quality of other components may have a decisive influence on the effectiveness and efficiency of the microwave heating of moulding sands with sand grains. In determining the ability to efficiently absorb the microwave radiation for mixtures which moulding sands are, the impact of all components influencing their individual technological parameters should be taken into account.

  6. Fecal indicators in sand, sand contact, and risk of enteric illness among beachgoers

    Science.gov (United States)

    Heaney, Christopher D.; Sams, Elizabeth; Dufour, Alfred P.; Brenner, Kristen P.; Haugland, Richard A.; Chern, Eunice; Wing, Steve; Marshall, Stephen; Love, David C.; Serre, Marc; Noble, Rachel; Wade, Timothy J.

    2011-01-01

    Background Beach sand can harbor fecal indicator organisms and pathogens, but enteric illness risk associated with sand contact remains unclear. Methods In 2007, visitors at two recreational marine beaches were asked on the day of their visit about sand contact. Ten to 12 days later, participants answered questions about health symptoms since the visit. F+ coliphage, Enterococcus, Bacteroidales, fecal Bacteroides, and Clostridium spp. in wet sand were measured using culture and molecular methods. Results We analyzed 144 wet sand samples and completed 4,999 interviews. Adjusted odds ratios (aORs) were computed, comparing those in the highest tertile of fecal indicator exposure with those who reported no sand contact. Among those digging in sand compared with those not digging in sand, a molecular measure of Enterococcus spp. (calibrator cell equivalents/g) in sand was positively associated with gastrointestinal (GI) illness (aOR = 2.0 [95% confidence interval (CI) = 1.2–3.2]) and diarrhea (2.4 [1.4–4.2]). Among those buried in sand, point estimates were greater for GI illness (3.3 [1.3–7.9]) and diarrhea (4.9 [1.8–13]). Positive associations were also observed for culture-based Enterococcus (colony-forming units/g) with GI illness (aOR digging = 1.7 [1.1–2.7]) and diarrhea (2.1 [1.3–3.4]). Associations were not found among non-swimmers with sand exposure. Conclusions We observed a positive relationship between sand contact activities and enteric illness as a function of concentrations of fecal microbial pollution in beach sand. PMID:22157306

  7. Murzuk Sand Sea, Sahara Desert, Libya, Africa

    Science.gov (United States)

    1993-01-01

    This near vertical view of the Murzuk Sand Sea, Sahara Desert, Libya (22.5N, 13.0E) shows the very diverse landscape that is part of the great Sahara Desert of North Africa. The vast expanse of sand dunes known as the Murzuk sand Sea of Libya and the adjacent rock outcrops support little human habitation. In fact, the tiny village of Murzuk with its center pivot, swing arm irrigated agriculture complex is the only sign of life in the region.

  8. Harry Sands (1917-2007).

    Science.gov (United States)

    Ochroch, Ruth

    2009-01-01

    To everyone who knew and had worked with him, the death of Harry Sands on January 3, 2007, three days before his 90th birthday, resounded as though a mighty oak had fallen. Harry was a giant of a man, both as a human being and as a psychologist. Harry was born January 6, 1917, on the Lower East Side of Manhattan to Russian immigrant parents who ran a laundry. His bachelor's degree in psychology (1941) and his doctoral degree (1952) were both earned at New York University. Harry became a member of the American Psychological Association (APA) in 1943. With his breadth of experience and knowledge, as well as his firm foundation in management and finance, he eventually became a financial advisor to the APA Practice Directorate as well as to the American Psychological Foundation. As the executive director of the Postgraduate Center for Mental Health, Harry made creative strides to improve both the public awareness of the organization as well as its fiscal health. Harry was an active writer and researcher, with a particular interest in epilepsy and various psychoanalytic topics. 2009 APA, all rights reserved

  9. Lab-scale pyrolysis of the Automotive Shredder Residue light fraction and characterization of tar and solid products.

    Science.gov (United States)

    Anzano, Manuela; Collina, Elena; Piccinelli, Elsa; Lasagni, Marina

    2017-06-01

    The general aim of this study is the recovery of Automotive Shredder Residue (ASR). The ASR light fraction, or car fluff, that was collected at an Italian shredding plant was pyrolysed at various temperatures (500-800°C) in a lab-scale reactor. The condensable gases (tar) and solid residue yields increased with decreasing temperature, and these products were characterized to suggest a potential use to reclaim them. The higher heating value (HHV) of tar was 34-37MJ/kg, which is comparable with those of fossil fuels. Furthermore, the ash content was low (0.06-4.98%). Thus, tar can be used as an alternative fuel. With this prospect, the concentrations of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in tar were determined. The toxicity of tar changes with temperature (1-5ng I-TEQ/g), and the PCDFs significantly contribute to tar toxicity, which was 75-100% with a maximum of 99.6% at 700°C. Regarding the characterization of the solid residue, the low HHV (2.4-3.3MJ/kg) does not make it suitable for energy recovery. Regarding material recovery, we considered its use as a filler in construction materials or a secondary source for metals. It shows a high metal concentration (280,000-395,000mg/kg), which is similar at different pyrolysis temperatures. At 500°C, polycyclic aromatic hydrocarbons (PAHs) were not detected in the solid residue, whereas the maximum total PAH concentration (19.41ng/g, 700°C) was lower than that in fly ash from MSWI. In conclusion, 500°C is a suitable pyrolysis temperature to obtain valuable tar and solid residue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Sand Lake WMD vegetation mapping project update

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Final report on the vegetation mapping project at Sand Lake Wetland Management District. This project is being completed by the use of SPRING software and ground...

  11. Displacement pile installation effects in sand

    NARCIS (Netherlands)

    Beijer-Lundberg, A.

    2015-01-01

    Installation effects govern the post-installation behaviour of displacement piles in sand. These effects are currently not completely understood. Suitable experimental techniques to model these installation effects include field, laboratory and experimental models. In the current thesis a

  12. 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.

  13. Tar removal from biomass gasification streams: processes and catalysts; Remocao do alcatrao de correntes de gaseificacao de biomassa: processos e catalisadores

    Energy Technology Data Exchange (ETDEWEB)

    Quitete, Cristina P.B. [Centro de Pesquisa e Desenvolvimento Leopoldo Americo Miguez de Mello (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Processos de Conversao de Biomassa; Souza, Mariana M.V.M., E-mail: mmattos@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Escola de Quimica

    2014-07-01

    Biomass gasification is a technology that has attracted great interest in synthesis of biofuels and oxo alcohols. However, this gas contains several contaminants, including tar, which need to be removed. Removal of tar is particularly critical because it can lead to operational problems. This review discusses the major pathways to remove tar, with a particular focus on the catalytic steam reforming of tar. Few catalysts have shown promising results; however, long-term studies in the context of real biomass gasification streams are required to realize their potential. (author)

  14. Effect of tar fractions from coal gasification on nickel-yttria stabilized zirconia and nickel-gadolinium doped ceria solid oxide fuel cell anode materials

    Science.gov (United States)

    Lorente, E.; Berrueco, C.; Millan, M.; Brandon, N. P.

    2013-11-01

    The allowable tar content in gasification syngas is one of the key questions for the exploitation of the full potential of fuel cell concepts with integrated gasification systems. A better understanding of the interaction between tars and the SOFC anodes which leads to carbon formation and deposition is needed in order to design systems where the extent of gas cleaning operations is minimized. Model tar compounds (toluene, benzene, naphthalene) have been used in experimental studies to represent those arising from biomass/coal gasification. However, the use of toluene as a model tar overestimates the negative impact of a real gasification tar on SOFC anode degradation associated with carbon formation. In the present work, the effect of a gasification tar and its distillation fractions on two commercially available fuel cell anodes, Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium doped ceria), is reported. A higher impact of the lighter tar fractions was observed, in terms of more carbon formation on the anodes, in comparison with the whole tar sample. The characterization of the recovered tars after contact with the anode materials revealed a shift towards a heavier molecular weight distribution, reinforcing the view that these fractions have reacted on the anode.

  15. Pragmatics of reclaimed sand quality assessment recovered nowadays from various used sand systems

    Directory of Open Access Journals (Sweden)

    J. Dańko

    2010-04-01

    Full Text Available The assessment of the reclamation degree of used sands is not a simple, clearly defined issue. The great variety of technologies ofmoulding and core sands, based on the organic and inorganic binders does not allow the use of a single, universal index assessing thedegree of reclamation. The article presents the problems of research relating to selection of proper criteria for assessing the degree ofreclamation process of used moulding and core sands deriving from different technologies. The most often applied in practice types ofused sands and the most adequate in practice methods of assessing the degrees of their reclamation were characterized.

  16. Sand Dune Encroachment and Desertification Processes of the Rigboland Sand Sea, Central Iran.

    Science.gov (United States)

    Ahmady-Birgani, Hesam; McQueen, Kenneth G; Moeinaddini, Mazaher; Naseri, Hamidreza

    2017-05-08

    Early studies on sand dune movement and desertification in Iran have not always been convincingly demonstrated because of problems with the field-based measurements. In some areas where various land uses have been engulfed by aeolian sand dunes, desertification is clear, but in other less settled areas, it may not be so obvious. The objective of this study is to demonstrate encroachments of the Rigboland sand sea, central Iran, in its different directions and variable magnitude rates. Determining the rate and direction of the sand sea movements is critical for specifying which lands should be prioritized and quickly protected. The study has trialed a change detection technique which uses a Cross-Tabulation module to compare two available LandsatTM images over the Rigboland sand sea. This indicates that within a ten-year span (from 1988 to 1998) more than 200 ha/yr were added to the Rigboland sand sea, from the alluvial fan landforms in the eastern upstream, outer margins of the Rigboland sand sea. Coupled with GIS techniques, this type of analysis of the remote sensing (RS) images provides an effective tool for the monitoring and prognostication of sand dune movement and sand sea change.

  17. Characteristics of Zircon in Placer Deposits along the West Coast of South Africa

    NARCIS (Netherlands)

    Philander, C.; Rozendaal, A.; de Meijer, R.J.

    Mining along the west coast of South Africa is dominated by the exploitation of onshore and offshore diamond deposits. The relatively recent discovery of vast resources of heavy minerals in the area has resulted in the establishment of a major related industry. Today, Namakwa Sands is a

  18. Vulnerability and fate of a coastal sand dune complex, Rosetta-Idku, northwestern Nile Delta, Egypt

    Science.gov (United States)

    El Banna, Mahmoud M.

    2008-05-01

    Types, distribution, and origin of recent sand dunes between Rosetta and Idku, in the western sector of the Nile Delta, Egypt were investigated. Sand samples from the dunes, beach, and seafloor were studied for grain size distribution and mineralogical composition. It has been found that most of the dunes in the study area have been subjected to deterioration and removal due to the construction of buildings and the International Coastal Highway. The remnant constitutes a damaged belt of foredunes that extends from El Bouseily village to the west of Idku town. The dune’s origin is interpreted to be the result of coastal drifting and the subsequent transport of sediments of the former Canopic Nile branch eastward by the predominant longshore current and by aeolian processes. The blown sand grains accumulated to form a belt of coastal sand dunes of original longitudinal and crescentic forms. Urbanization of the coast has severely altered the landscape. The study area is considered vulnerable to the impacts of climate change and the expected rise in sea level. The outcome of potential sea level rise is serious; erosion problems are expected to be exacerbated and vast areas from land and property would be lost. Thus, protection and preservation the remaining dunes in the study area are vital requirements for shore protection.

  19. How extensive is the effect of modern farming on bird communities in a sand dune desert?

    Directory of Open Access Journals (Sweden)

    Faris Khoury

    2009-12-01

    Full Text Available Bird community structure and diversity measures in sand dune habitats far from and close to modern farms in Wadi Araba, south-west Jordan, were compared using 52 line transects for breeding birds and habitat variables. A change in the bird community of sand dunes surrounding farming projects was measured to a distance of 1 km, but could neither be related to changes in habitat structure nor to the activity of op- portunistic predators (Red Fox as these did not vary significantly between the two samples. The farms included lines of trees and offered a constant source of water, which attracted a variety of opportunistic species, thus increasing bird diversity and total bird abundances. The absence of characteristic ground-dwelling species of open sand dune habitats in the structurally intact sand dunes surrounding farms was likely to be the result of localized, but effectively far-reaching habitat modification (farms acting as barriers and/or competition with some of the opportunistic species, which were common around farms.

  20. Novel foraging in the swash zone on Pacific sand crabs (Emerita analoga, Hippidae) by mallards

    Science.gov (United States)

    Lafferty, Kevin D.; McLaughlin, John P.; Dugan, Jenifer E.

    2013-01-01

    Mallards (Anas platyrhynchos) have been observed foraging on intertidal Pacific sand crabs (Hippidae, Emerita analoga) in the swash zone of sandy beaches around Coal Oil Point Reserve, California, and several other beaches on the west coast since at least November 2010. Unlike foraging shorebirds, Mallards do not avoid incoming swashes. Instead, the incoming swash lifts and deposits them down the beach. Shorebirds and diving ducks commonly feed on sand crabs, but sand crabs appear to be a novel behavior and food source for Mallards. Previous surveys of beaches did not report foraging Mallards on regional beaches, whereas foraging Mallards were common in contemporary (recent) surveys and anecdotal reports. Observations of this potentially new behavior were separated by as much as 1,300 km, indicating that this was not a local phenomenon. Mallards foraged singly, in pairs, and in flocks. An expansion of diet to sand crabs carries risks of exposure to surf, human disturbance, high salt intake, and transmission of acanthocephalan and trematode parasites for Mallards but has the benefit of providing a dependable source of animal protein.

  1. Development of secondary chamber for tar cracking–improvement of wood pyrolysis performance in pre-vacuum chamber

    Science.gov (United States)

    Siahaan, S.; Homma, H.; Homma, H.

    2018-02-01

    Energy crisis and global warming, in other words, climate change are critical topics discussed in various parts of the world. Global warming primarily result from too much emission of carbon dioxide (CO2) in the atmosphere. To mitigate global warming, or climate change and improve electrification in rural areas, wood pyrolysis technology is developed in a laboratory scale, of which gases are directly applicable to the gas engine generator. Our laboratory has developed a prototype of wood pyrolysis plant with a pre-vacuum chamber. However, tar yield was around 40 wt% of feedstock. This research aims to reduce tar yield by secondary tar cracking. For the secondary tar cracking, a secondary pre-vacuum chamber is installed after primary pre-vacuum chamber. Gases generated in the primary pre-vacuum chamber are lead into the secondary chamber that is heated up to 1000 K. This paper reports performance of the secondary chamber for secondary tar cracking in homogeneous mode and heterogeneous mode with char.

  2. Impact of Genetic Variations in HIV-1 Tat on LTR-Mediated Transcription via TAR RNA Interaction

    Directory of Open Access Journals (Sweden)

    Larance Ronsard

    2017-04-01

    Full Text Available HIV-1 evades host defense through mutations and recombination events, generating numerous variants in an infected patient. These variants with an undiminished virulence can multiply rapidly in order to progress to AIDS. One of the targets to intervene in HIV-1 replication is the trans-activator of transcription (Tat, a major regulatory protein that transactivates the long terminal repeat promoter through its interaction with trans-activation response (TAR RNA. In this study, HIV-1 infected patients (n = 120 from North India revealed Ser46Phe (20% and Ser61Arg (2% mutations in the Tat variants with a strong interaction toward TAR leading to enhanced transactivation activities. Molecular dynamics simulation data verified that the variants with this mutation had a higher binding affinity for TAR than both the wild-type Tat and other variants that lacked Ser46Phe and Ser61Arg. Other mutations in Tat conferred varying affinities for TAR interaction leading to differential transactivation abilities. This is the first report from North India with a clinical validation of CD4 counts to demonstrate the influence of Tat genetic variations affecting the stability of Tat and its interaction with TAR. This study highlights the co-evolution pattern of Tat and predominant nucleotides for Tat activity, facilitating the identification of genetic determinants for the attenuation of viral gene expression.

  3. Pyrolysis characteristics and kinetics of acid tar waste from crude benzol refining: A thermogravimetry-mass spectrometry analysis.

    Science.gov (United States)

    Chihobo, Chido H; Chowdhury, Arindrajit; Kuipa, Pardon K; Simbi, David J

    2016-12-01

    Pyrolysis is an attractive thermochemical conversion technology that may be utilised as a safe disposal option for acid tar waste. The kinetics of acid tar pyrolysis were investigated using thermogravimetry coupled with mass spectrometry under a nitrogen atmosphere at different heating rates of 10, 15 and 20 K min(-1) The thermogravimetric analysis shows three major reaction peaks centred around 178 °C, 258 °C, and 336 °C corresponding to the successive degradation of water soluble lower molecular mass sulphonic acids, sulphonated high molecular mass hydrocarbons, and high molecular mass hydrocarbons. The kinetic parameters were evaluated using the iso-conversional Kissinger-Akahira-Sunose method. A variation in the activation energy with conversion revealed that the pyrolysis of the acid tar waste progresses through complex multi-step kinetics. Mass spectrometry results revealed a predominance of gases such as hydrogen, methane and carbon monoxide, implying that the pyrolysis of acid tar waste is potentially an energy source. Thus the pyrolysis of acid tar waste may present a viable option for its environmental treatment. There are however, some limitations imposed by the co-evolution of corrosive gaseous components for which appropriate considerations must be provided in both pyrolysis reactor design and selection of construction materials. © The Author(s) 2016.

  4. PAH volatilization following application of coal-tar-based pavement sealant

    Science.gov (United States)

    Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

    2012-01-01

    Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (ΣPAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 μg m-2 h-1 and decreased rapidly during the 45 days after application to 160 μg m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ΣPAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ΣPAH8 lost to the atmosphere on the basis of air sampling (2–3 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ΣPAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

  5. Sürdürülebilir Tarımsal Pazarlama Girişimleri

    Directory of Open Access Journals (Sweden)

    Hakan Adanacıoğlu

    2015-07-01

    Full Text Available Sürdürülebilir pazarlama, pazarlama stratejileri geliştirilirken çevresel, sosyal eşitlik ve ekonomik kaygılar üzerine eşit derecede odaklanan bütünsel bir yaklaşım olarak ifade edilmektedir. Bu çalışmada esas olarak, sürdürülebilir tarımsal pazarlama alanında dünyada ve Türkiye’de uygulanan girişimlerin incelenerek tartışılması ve Türkiye’deki tarımsal pazarlama girişimlerinin performansının geliştirilmesi açısından bazı öneriler getirilmesi amaçlanmıştır. Dünyada uygulamaları görülen sürdürülebilir tarımsal pazarlama girişimlerinin bir kısmının sivil organizasyonlar aracılığıyla yapıldığı belirlenmiştir. Bunun yanında; çiftçiler, tüketiciler, gıda işleyicileri ve perakendecilerin girişimleri ile başlatılan sürdürülebilir tarımsal pazarlama girişimleri de bulunmaktadır. Türkiye’de sürdürülebilir tarımsal pazarlama girişimlerine yönelik başarılı örneklerin az olması ve pek yaygınlaştırılamaması nedeniyle, bu girişimlerin artırılmasına yönelik uzun vadeli stratejilerin belirlenmesi önemli görülmektedir. Bu kapsamda öncelikle, hükümet tarafından tarımsal pazarlamayı geliştirici yönde verilen desteklerde sunulan projelerin sürdürülebilir pazarlamanın ilkeleri olan çevresel, ekonomik ve sosyal boyutları incelenerek, gerekli koşulları sağlayıp sağlamadığına bakılmalıdır. Türkiye’de sürdürülebilir tarımsal pazarlama uygulamalarının daha hızlı yayılması ve benimsenmesi için, bu uygulamalara yönelik üreticilerin eğitilmesi ve yönlendirilmesi yanında, projelerin üretilmesi aşamalarında organizasyon desteğine ihtiyaç bulunmaktadır. Bu organizasyon, başta sivil toplum kuruluşları olmak üzere, yerel yönetimler, tarımsal üretici birlikleri ve kooperatifler aracılığı ile gerçekleştirilebilir. Türkiye’de uygulanması olası sürdürülebilir tarımsal pazarlama girişimlerinde do

  6. Nakamura Ryûtarô’s Anime, Serial Experiments, Lain (1998

    Directory of Open Access Journals (Sweden)

    Tamae KOBAYASHI PRINDLE

    2015-07-01

    Full Text Available This paper introduces Nakamura Ryūtarō’s anime, Serial Experiments, Lain (1998 as a new type of anime, a genre nameable as an “expository anime”, for the reason that it creates a diachronic story out of a synchronic aspect of a certain field of science. The overarching topic of Experiments is electronics, focusing on the comparison between digital and analogue communication systems. Experiments unfolds the rationales, potentials, and effects of the two types of communication systems using the perceptions of the major character, a thirteen-year old girl, Rein, as well as other supporting characters.

  7. Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Suneel, V.; Vethamony, P.; Zakaria, M.P.; Naik, B.G.; Prasad, K.V.

    version: Mar. Pollut. Bull., vol.70; 2013; 81-89 Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques V. Suneel1, 1CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India Email id...: vasimallas@nio.org P. Vethamony1*, 1CSIR-National Institute of Oceanography, Dona Paula, Goa 403004, India Email id: mony@nio.org M. P. Zakaria2, 2Faculty of Environmental Studies, Universiti Putra Malaysia, 43400 UPM Serdang, Malaysia Email id...

  8. Nakamura Ryûtarô’s Anime, Serial Experiments, Lain (1998)

    OpenAIRE

    Tamae KOBAYASHI PRINDLE

    2015-01-01

    This paper introduces Nakamura Ryūtarō’s anime, Serial Experiments, Lain (1998) as a new type of anime, a genre nameable as an “expository anime”, for the reason that it creates a diachronic story out of a synchronic aspect of a certain field of science. The overarching topic of Experiments is electronics, focusing on the comparison between digital and analogue communication systems. Experiments unfolds the rationales, potentials, and effects of the two types of communication systems using th...

  9. Environmental Forensics : Compound Specific Isotope Analysis Of PAHs. Study Of A Former Coal Tar Plant.

    Science.gov (United States)

    Assal, A.; Doherty, R.; Dickson, K.; Kalin, R. M.

    2008-12-01

    Stable carbon isotopic fingerprints of PAHs obtained by GC-IRMS have often been used in source apportionment studies. The use of PAHs in environmental forensics relies on the assumption that carbon isotopic fractionation caused by microbial degradation is less significant for these heavy molecular weight compounds than for lighter molecules such as chlorinated solvents or BTEX. Carbon isotopic fractionation of PAHs during degradation is still not well understood. The aim of this study was to assess the potential of CSIA of PAHs for environmental forensics applications at a complex (hydrogeology affected by tidal fluxes) former coal tar plant. In this work, soil samples from a tar works site were analyzed. The tar works operated on the site over a period of sixty years. A source apportionment study was first carried out based on 90 target PAHs quantified by GC-MS. These results were then compared to carbon isotope fingerprints. The separation of compounds of interest from co-extracted interfering peaks is a crucial prerequisite of CSIA by GC-IRMS. Hence, a sample preparation method which allowed the determination of precise carbon isotope signatures for up to 35 compounds per soil extract was developed, validated and applied to the samples previously analyzed by GC- MS. Although most soil samples were shown to be related to the point source tar contamination, PAHs ratios and principal component analysis of abundances highlighted some samples with unusual patterns, suggesting the input of a second source of contaminants. However, no statistically significant variation of the isotopic fingerprints of heavy molecular weight PAHs of these samples was observed. This was inconsistent with the first diagnosis. Since evidence was provided that most samples were only affected by a single source of contaminants, carbon isotopic fractionation was investigated in-situ. Importantly, naphthalene and 2- and 1- methylnaphthalenes isotopic fractionation was observed in a vertical

  10. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice-age deposits were reactivated as drift sand

  11. Contribution of laser altimetry images to the geomorphology of the Late Holocene inland drift sands of the European Sand Belt

    NARCIS (Netherlands)

    Jungerius, P.D.; Riksen, M.J.P.M.

    2010-01-01

    The paper explores the possibilities of applying the analysis of laser altimetry images to Dutch drift sands. All along the European Sand Belt, which stretches from Great Britain to the Ural Mountains, Late Glacial cover sands, river dunes and other ice–age deposits were reactivated as drift sand

  12. 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)

  13. An evaluation of aeolian sand transport models using four different sand traps at the Hors, Texel

    NARCIS (Netherlands)

    Hijma, M.P.; Lodder, Quirijn J.

    2001-01-01

    This report shows the result of an evaluation of how 12 aeolian sand transport models perform on a beach in Northwest-Europe. Their predictions are compared to measured rates of sand transport using four different traps. The efficiency of the different types of traps was also evaluated. From this it

  14. Simulating and understanding sand wave variation: A case study of the Golden Gate sand waves

    Science.gov (United States)

    Sterlini, F.; Hulscher, S.J.M.H.; Hanes, D.M.

    2009-01-01

    In this paper we present a detailed comparison between measured features of the Golden Gate sand wave field and the results of a nonlinear sand wave model. Because the Golden Gate sand waves exhibit large variation in their characteristics and in their environmental physics, this area gives us the opportunity to study sand wave variation between locations, within one well-measured, large area. The nonlinear model used in this paper is presently the only tool that provides information on the nonlinear evolution of large-amplitude sand waves. The model is used to increase our understanding of the coupling between the variability in environmental conditions and the sand wave characteristics. Results show that the model is able to describe the variation in the Golden Gate sand waves well when both the local oscillating tidal current and the residual current are taken into account. Current and water depth seem to be the most important factors influencing sand wave characteristics. The simulation results give further confidence in the underlying model hypothesis and assumptions. Copyright 2009 by the American Geophysical Union.

  15. 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.

  16. Fungal Biodegradation of Tannins from Creosote Bush (Larrea tridentata and Tar Bush (Fluorensia cernua for Gallic and Ellagic Acid Production

    Directory of Open Access Journals (Sweden)

    Janeth Ventura

    2008-01-01

    Full Text Available In the present work, the production of two potent antioxidants, gallic and ellagic acids, has been studied using solid-state fermentation (SSF of tannin-rich aqueous plant extracts impregnated in polyurethane foam. Extracts from creosote and tar bush were ino-culated with Aspergillus niger PSH spores and impregnated in the polyurethane support.The kinetics of the fermentation was monitored every 24 h. The maximum biodegradation of hydrolysable and condensed tannins was, respectively, 16 and 42 % in creosote bush, and 40 and 83 % in tar bush. The maximal productions of gallic and ellagic acid (152 and177 %, respectively were reached with aqueous extracts of creosote bush. Tar bush extracts inoculated with A. niger PSH spores produced only gallic acid (92 %, while ellagic acid was not recovered after the fermentation process. Results demonstrated the potential use of these plants as a source for the production of antioxidants.

  17. Phase-equilibria for design of coal-gasification processes: dew points of hot gases containing condensible tars. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Prausnitz, J.M.

    1980-05-01

    This research is concerned with the fundamental physical chemistry and thermodynamics of condensation of tars (dew points) from the vapor phase at advanced temperatures and pressures. Fundamental quantitative understanding of dew points is important for rational design of heat exchangers to recover sensible heat from hot, tar-containing gases that are produced in coal gasification. This report includes essentially six contributions toward establishing the desired understanding: (1) Characterization of Coal Tars for Dew-Point Calculations; (2) Fugacity Coefficients for Dew-Point Calculations in Coal-Gasification Process Design; (3) Vapor Pressures of High-Molecular-Weight Hydrocarbons; (4) Estimation of Vapor Pressures of High-Boiling Fractions in Liquefied Fossil Fuels Containing Heteroatoms Nitrogen or Sulfur; and (5) Vapor Pressures of Heavy Liquid Hydrocarbons by a Group-Contribution Method.

  18. Processing of a Silesian bituminous coal tar mixture at 600 atm to heavy oil excess in a 10-liter oven

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer, H.

    1942-10-28

    An analysis was made of a bituminous coal tar mixture for consideration as raw material for Blechhammer. A breakdown of the composition and yield charts is provided. A table compared it to a coke tar pitch and a bituminous tar mixture from a different carbonization process and its yields were approximately between the yield values of these two. Although the sludge extraction produced sufficient yields in the experiment, the yields would not be as good within full-scale industry. A day by day progress description of the experimentation is provided including all operational details. The experimental results and the pros and cons are summarized briefly. Fifteen tables of data provide analysis of all the elements tested.

  19. Elution of Mixed Moulding Sands with the GEOPOL Binder and Core Sands with the Phenolic Resin

    Directory of Open Access Journals (Sweden)

    Holtzer M.

    2013-12-01

    Full Text Available Out of moulding and core sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. Depending on the kind of the applied resin under an influence of a temperature such compounds as for example BTEX group and polycyclic aromatic hydrocarbons (PAHs can be formed and released. During storing or economic utilization of used sand is possibility of eluting harmful substances into the environment. Therefore at assessing an influence of the used sand on the environment two above elements should be taken into consideration. Only such investigations provide the complete assessment of the given sand harmfulness.

  20. Ecosystem evaluation of post sand mining land in Cimalaka, Sumedang

    Directory of Open Access Journals (Sweden)

    A.R.F. Sholihah

    2014-01-01

    Full Text Available This research was conducted to evaluate ecosystem function of post-sand mining land in northern side of Layapan, Cimalaka, Sumedang, West Java (S 6o 47’ 33.68” and E 107o 58’18.73”, 744 m above sea level. Microclimate and soil characteristics measurements were carried out to describe the physical and chemical characteristics of the land. Vegetation analysis was conducted with plotting method. Ecosystem Function Analysis, including Landscape Function Analysis (LFA has been used to analyze the function of landscape. The results showed that average light intensity, air temperature and humidity were 15.2x103 ± 7.3x103 lux, 29.1±1.02oC and 69.7±7.5%. High light intensity made the air temperature rouse higher than normal, which is between 17.1oC to 22oC. As for the soil, soil organic content was 4-11%, porosity 4.65-24.43%, macronutrient content was low and C/N ratio was high. The results showed that LFA value for land stability was 33.24%, water infiltration 37.2%, nutrient cycle rate 15.28%. Those numbers showed that land condition was poor. From the LFA data, it was also known that vegetations had the highest contribution for all LFA parameters. From vegetation analysis, herbs species were 67 while bushes only 9, which at least 40 species were invasive alien species. Species with highest Important Value (IV from herb was Cajanus scarabaeoides and from bush was Mimosa pigra. Both of them are members of Fabaceae. It was concluded that the soil of this post sand mining land was highly nutrient poor; critical and couldn’t perform the regulation, habitat and biomass production function of ecosystem.

  1. HIV-1 TAR RNA spontaneously undergoes relevant apo-to-holo conformational transitions in molecular dynamics and constrained geometrical simulations.

    Science.gov (United States)

    Fulle, Simone; Christ, Nina Alexandra; Kestner, Eva; Gohlke, Holger

    2010-08-23

    We report all-atom molecular dynamics and replica exchange molecular dynamics simulations on the unbound human immunodeficiency virus type-1 (HIV-1) transactivation responsive region (TAR) RNA structure and three TAR RNA structures in bound conformations of, in total, approximately 250 ns length. We compare the extent of observed conformational sampling with that of the conceptually simpler and computationally much cheaper constrained geometrical simulation approach framework rigidity optimized dynamic algorithm (FRODA). Atomic fluctuations obtained by replica-exchange molecular dynamics (REMD) simulations agree quantitatively with those obtained by molecular dynamics (MD) and FRODA simulations for the unbound TAR structure. Regarding the stereochemical quality of the generated conformations, backbone torsion angles and puckering modes of the sugar-phosphate backbone were reproduced equally well by MD and REMD simulations, but further improvement is needed in the case of FRODA simulations. Essential dynamics analysis reveals that all three simulation approaches show a tendency to sample bound conformations when starting from the unbound TAR structure, with MD and REMD simulations being superior with respect to FRODA. These results are consistent with the experimental view that bound TAR RNA conformations are transiently sampled in the free ensemble, following a conformation selection model. The simulation-generated TAR RNA conformations have been successfully used as receptor structures for docking. This finding has important implications for RNA-ligand docking in that docking into an ensemble of simulation-generated RNA structures is shown to be a valuable means to cope with large apo-to-holo conformational transitions of the receptor structure.

  2. Fracturing in the oil-sands reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y.; Yang, B. [Society of Petroleum Engineers (Canada); Xu, B. [BitCan G and E Inc (Canada)

    2011-07-01

    Oil sands reservoirs stimulation requires the use of steam or solvent in order to reduce oil viscosity, making for better recovery. Injection of these stimulants is generally achieved by hydro-fracturing and, given concerns over the impact of this on caprock integrity, a better understanding is needed of the phenomena involved during fracturing. Based on a review of the literature and on analytical, numerical and field data, this paper aims to explore the phenomena involved during hydro-fracturing of oil sands. Review of existing test data shows that oil sands have a clear dilatation tendency. Analytical derivation then compares the effects and occurrence of dilatation and tensile parting during hydro-fracturing, showing a dominance of dilatation, resulting in much higher porosity in the sands formation. Field data then confirmed these derivations, thus giving them an experimental validation. Glaciation is proposed as a cause for the presence of these phenomena in oil sands, thus the results can safely be extrapolated to other similar rock formations.

  3. Review of Novel Catalysts for Biomass Tar Cracking and Methane Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Mark A.

    2007-10-10

    A review of the literature was conducted to examine the performance of catalysts other than conventional nickel catalysts, and alkaline earth and olivine based catalysts for treating hot raw product gas from a biomass gasifier to convert methane and tars into synthesis gas. Metal catalysts other than Ni included precious metals Rh, Ru, Ir, Pt, and Pd, as well as Cu, Co, and Fe in limited testing. Nickel catalysts promoted with Rh, Zr, Mn, Mo, Ti, Ag, or Sn were also examined, as were Ni catalysts on Ce2O3, TiO2, ZrO2, SiO2, and La2O3. In general, Rh stood out as a consistently superior metal catalyst for methane reforming, tar cracking, and minimizing carbon buildup on the catalyst. Ru and Ir also showed significant improvement over Ni for methane reforming. Ceria stood out as good support material and particularly good promoter material when added in small quantities to another support material such as alumina, zirconia, or olivine. Other promising supports were lanthana, zirconia, and titania.

  4. Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

    Science.gov (United States)

    Engle, Mark A; Radke, Lawrence F; Heffern, Edward L; O'Keefe, Jennifer M K; Hower, James C; Smeltzer, Charles D; Hower, Judith M; Olea, Ricardo A; Eatwell, Robert J; Blake, Donald R; Emsbo-Mattingly, Stephen D; Stout, Scott A; Queen, Gerald; Aggen, Kerry L; Kolker, Allan; Prakash, Anupma; Henke, Kevin R; Stracher, Glenn B; Schroeder, Paul A; Román-Colón, Yomayra; ter Schure, Arnout

    2012-03-15

    Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires. Published by Elsevier B.V.

  5. Distribution and transport of coal tar-derived PAHs in fine-grained residuum

    Energy Technology Data Exchange (ETDEWEB)

    Vulava, V.M.; Mckay, L.D.; Driese, S.G.; Menn, F.M.; Sayler, G.S. [University of Tennessee, Knoxville, TN (United States)

    2007-06-15

    We investigated the distribution and transport of coal tar-derived polycyclic aromatic hydrocarbons (PAHs) in fine-grained residuum and alluvial floodplain deposits that underlie a former manufactured gas plant. All 16 USEPA priority pollutant PAHs are present at this site and have penetrated the entire 4-5 m thickness of clayey sediments, which unconformably overly limestone bedrock. Concentrations of less hydrophobic PAHs (e.g., naphthalene, 0.011-384 mg kg{sup -1}) were about 10 times higher than those of highly hydrophobic PAHs (e.g., benzo(g, h, i)perylene -0.002 to 56.03 mg kg{sup -1}). Microscopic examination of thin-sections of the clay-rich sediments showed that fractures and rootholes, which can act as pathways for flow, occur throughout the profiles. However, in the vast majority of samples in which PAHs were detected, there was no detectable tar residue, suggesting that much of the transport occurred in the dissolved phase. The widespread distribution of PAHs is most likely due to diffusion-controlled exchange between the fast-flow pathways in the fractures and rootholes and the relatively immobile water in the fine-grained matrix. This implies that fractures and rootholes can play a major role in controlling transport of highly hydrophobic compounds in fine-grained sediments, which would otherwise act as barriers to contaminant migration.

  6. Modelling of thermal removal of tars in a high temperature stage fed by a plasma torch

    Energy Technology Data Exchange (ETDEWEB)

    Fourcault, A. [Laboratoire Thermique Energetique et Procedes, LaTEP-ENSGTI, rue Jules Ferry, BP 7511, 64075 Pau Cedex (France); Europlasma, 21 rue Daugere, 33520 Bruges (France); Marias, F. [Laboratoire Thermique Energetique et Procedes, LaTEP-ENSGTI, rue Jules Ferry, BP 7511, 64075 Pau Cedex (France); Michon, U. [Europlasma, 21 rue Daugere, 33520 Bruges (France)

    2010-09-15

    The thermal degradation of tars in a chamber fed by a non-transferred plasma torch is theoretically examined in this study. The input of this reactor is a product gas coming from a gasification unit with a temperature of about 800 C. According to literature, naphthalene and toluene are chosen as model compounds to represent the behaviour of their classes. According to this choice and to the data available in the literature, a reaction pathway for the thermal degradation of tars and its associated kinetics are proposed in this study. This mechanism is introduced in a CSTR model in order to check the influence of the operating parameters of the reactor on the degradation efficiency. These computations clearly show that a complete conversion of toluene (>99.9%) and an important conversion of naphthalene (96.7%) can be reached in the reactor, with concentration levels compatible with the further use of gas engines for electricity production. This theoretical study requires to be validated by comparison with experimental results. (author)

  7. Mass Transfer Coefficientin Stirred Tank for p-Cresol Extraction Process from Coal Tar

    Science.gov (United States)

    Fardhyanti, D. S.; Tyaningsih, D. S.; Afifah, S. N.

    2017-04-01

    Indonesia is a country that has a lot of coal resources. The Indonesian coal has a low caloric value. Pyrolysis is one of the process to increase the caloric value. One of the by-product of the pyrolysis process is coal tar. It contains a lot of aliphatic or aromatic compounds such asp-cresol (11% v/v). It is widely used as a disinfectant. Extractionof p-Cresol increases the economic value of waste of coal. The aim of this research isto study about mass tranfer coefficient in the baffled stirred tank for p-Cresolextraction from coal tar. Mass transfer coefficient is useful for design and scale up of industrial equipment. Extraction is conducted inthe baffled stirred tank equipped with a four-bladed axial impeller placed vertically in the vessel. Sample for each time processing (5, 10, 15, 20, 25 and 30minutes) was poured into a separating funnel, settled for an hour and separated into two phases. Then the two phases were weighed. The extract phases and raffinate phases were analyzed by Spectronic UV-Vis. The result showed that mixing speed of p-Cresol extraction increasesthe yield of p-Cresol and the mass transfer coefficient. The highest yield of p-Cresol is 49.32% and the highest mass transfer coefficient is 4.757 x 10-6kg/m2s.

  8. Production of aromatics through current-enhanced catalytic conversion of bio-oil tar.

    Science.gov (United States)

    Bi, Peiyan; Yuan, Yanni; Fan, Minghui; Jiang, Peiwen; Zhai, Qi; Li, Quanxin

    2013-05-01

    Biomass conversion into benzene, toluene and xylenes (BTX) can provide basic feedstocks for the petrochemical industry, which also serve as the most important aromatic platform molecules for development of high-end chemicals. Present work explored a new route for transformation of bio-oil tar into BTX through current-enhanced catalytic conversion (CECC), involving the synergistic effect between the zeolite catalyst and current to promote the deoxygenation and cracking reactions. The proposed transformation shows an excellent BTX aromatics selectivity of 92.9 C-mol% with 25.1 wt.% yield at 400 °C over usual HZSM-5 catalyst. The study of the model compounds revealed that the groups such as methoxy, hydroxyl and methyl in aromatics can be effectively removed in the CECC process. Present transformation potentially provides an important approach for production of the key petrochemicals of BTX and the overall use of bio-oil tar derived from bio-oil or biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Preparation and Characterization of Malaysian Dolomites as a Tar Cracking Catalyst in Biomass Gasification Process

    Directory of Open Access Journals (Sweden)

    M. A. A. Mohammed

    2013-01-01

    Full Text Available Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites underwent two stages of decomposition during the calcination process. The X-ray diffraction and Fourier-transform infrared spectra analyses showed that thermal treatment of dolomite played a significant role in the disappearance of the CaMg(CO32 phase, producing the MgO-CaO form of dolomite. The scanning electron microscopy microphotographs of dolomite indicated that the morphological properties were profoundly affected by the calcination process, which led to the formation of a highly porous surface with small spherical particles. In addition, the calcination of dolomite led to the elimination of carbon dioxide and increases in the values of the specific surface area and average pore diameter, as indicated by surface area analysis. The results showed that calcined Malaysian dolomites have great potential to be applied as tar-cracking catalysts in the biomass gasification process based on their favorable physical properties.

  10. Co-carcinogenesis: Human Papillomaviruses, Coal Tar Derivatives, and Squamous Cell Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Harry W. Haverkos

    2017-11-01

    Full Text Available Cervical cancer (CC is the fourth most common cancers among women worldwide. Human papillomaviruses (HPVs play a major role in the etiology of CC, with several lines of epidemiologic and experimental evidence supporting a role for non-viral (co-carcinogens and host genetic factors in controlling the risk for progression to neoplasia among HPV-infected individuals. The role of co-carcinogens in the development of CC is significant in the developing world where poor sanitation and other socio-economic conditions increase the infectious cancer burden. Here, we discuss how exposure to environmental factors such as coal tar derivatives from cigarette smoking, tar-based sanitary products, and inhaled smoke from biomass-burning stoves, could activate host pathways involved in development of HPV-associated squamous cell cancers in resource-limited settings. Understanding interactions between these pathways with certain oncogenic HPV genotypes may guide implementation of strategies for control and treatment of HPV-associated cancers that develop in populations at high risk of exposure to various co-carcinogens.

  11. The effects of topical corticosteroids and a coal tar preparation on dithranol-induced irritation in patients with psoriasis

    Energy Technology Data Exchange (ETDEWEB)

    Swinkels, O.Q.J.; Kucharekova, M.; Prins, M.; Gerritsen, M.J.P.; van der Valk, P.G.M.; van de Kerkhof, P.C.M. [University of Nijmegen, Nijmegen (Netherlands). Medical Center

    2003-02-01

    Dithranol has been a mainstay in the treatment of psoriasis for more than 80 years. Although a safe approach, the irritation of the clinically uninvolved perilesional skin remains a major limitation of this treatment. Corticosteroids and coal tar solution have an anti-inflammatory potential. The aim of the present study was to investigate the clinical and cell-biological effects of two topical corticosteroids and a coal tar preparation on dithranol-irritated skin. The expression of epidermal proliferation, differentiation and inflammation markers and the clinical irritation scores indicate that the application of a high potency corticosteroid is the best approach to minimise dithranol irritation.

  12. Characteristics of a solid coal tar sampled from a contaminated soil and of the organics transferred into water

    Energy Technology Data Exchange (ETDEWEB)

    Karim Benhabib; Pierre Faure; Michel Sardin; Marie-Odile Simonnot [Nancy Universite INPL-CNRS, Nancy (France). Laboratoire des Sciences du Genie Chimique

    2010-02-15

    Most often, only TOC and the concentrations of the 16 PAHs of the US EPA list are monitored in contaminated soils of former coking plants or MGPs. The objective of the present study was to provide a detailed characterization of the organic extracts of (i) coal tar particles sampled from a contaminated soil and (ii) of water at equilibrium with these particles. Chromatographic techniques were used (HPLC, GC-MS) as well as Fourier Transform Infrared Microscopy. An accurate description was obtained, showing the predominance of aromatic compounds in the coal tar and the preferential transfer of polar compounds and aliphatic hydrocarbons into water. 28 refs., 7 figs., 3 tabs.

  13. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 January 1996--31 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Suuberg, E.M.

    1996-09-01

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do not lend themselves well for application to very complex, poorly characterized coal tars. The methods based upon more global types of characterizations have not yet dealt much with the question of oxygenated functional groups. In short, only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well- established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. A significant amount of time has been devoted during this quarter to developing techniques for measurements of vapor pressures of coal tar related compounds, and mixtures, in a ``continuous`` mode, using the effusion technique.

  14. PRELIMINARY STUDY OF FISH CULTURE IN ABANDONED SAND MINING POOL

    Directory of Open Access Journals (Sweden)

    Bambang Gunadi

    2006-12-01

    Full Text Available One of main problems in freshwater aquaculture development in Indonesia, especially in Java, is unavailability of developing zone. It is important to find an underutilized area that meets for industrial scale freshwater aquaculture, i.e. sufficient water supply, wide area, and located in one area or zone. The abandoned mining (sand, tin, etc. pools distributed along the country might be the potential area for freshwater aquaculture business. For example, there are at least 13 water pools with total surface area of 250 ha at 15 km side of Citarum River in Karawang District (West Java Province. This study was conducted to obtain preliminary data about the prospect and potency of fish culture (tilapia, clariid catfish, and ‘patin’ catfish in abandoned sand-mining pools in Karawang District. Mini floating net cages of 1 x 1 x 1.5 m3 size were used for culturing fish, i.e. patin catfish (Pangasianodon hypophthalmus, nile tilapia (Oreochromis niloticus, and clariid catfish (Clarias gariepinus, separately. Patin catfish were stocked at a size of 2 g with a density of 300 fish per cage, tilapia were stocked at a size of 6 g with a density of 400 fish per cage, while  the clariid catfish were stocked at a size of 1.4 g with a density of 980 fish per cage. A floating commercial feed (30%—32% protein, 3%—5% fat was used at a daily rate of 9% biomass weight at the beginning and reduced gradually to 3% at the final culture period. Observed data showed that patin catfish grew from the initial size of 2.08 g to the final size 299.59 g in 5 months, nile tilapia grew from individual initial size of 5.92 g to the final size of 247.12 g in 14 weeks, and clariid catfish grew from initial size of 1.39 g to the final size of 73.10 g in 8 weeks. These three species were technically prospective for aquaculture development in the abandoned sand-mining pools.

  15. The formation of the patterns of desert shrub communities on the Western Ordos Plateau, China: the roles of seed dispersal and sand burial.

    Science.gov (United States)

    Wang, Yange; Yang, Xiaohui; Shi, Zhongjie

    2013-01-01

    The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0-1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3-6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession direction

  16. Sand ridge morphology and bedform migration patterns derived from bathymetry and backscatter on the inner-continental shelf offshore of Assateague Island, USA

    Science.gov (United States)

    Pendleton, Elizabeth; Brothers, Laura; Thieler, E. Robert; Sweeney, Edward

    2017-01-01

    The U.S. Geological Survey and the National Oceanographic and Atmospheric Administration conducted geophysical and hydrographic surveys, respectively, along the inner-continental shelf of Fenwick and Assateague Islands, Maryland and Virginia over the last 40 years. High resolution bathymetry and backscatter data derived from surveys over the last decade are used to describe the morphology and presence of sand ridges on the inner-continental shelf and measure the change in the position of smaller-scale (10–100 s of meters) seafloor features. Bathymetric surveys from the last 30 years link decadal-scale sand ridge migration patterns to the high-resolution measurements of smaller-scale bedform features. Sand ridge morphology on the inner-shelf changes across-shore and alongshore. Areas of similar sand ridge morphology are separated alongshore by zones where ridges are less pronounced or completely transected by transverse dunes. Seafloor-change analyses derived from backscatter data over a 4–7 year period show that southerly dune migration increases in magnitude from north to south, and the east-west pattern of bedform migration changes ~ 10 km north of the Maryland-Virginia state line. Sand ridge morphology and occurrence and bedform migration changes may be connected to observed changes in geologic framework including topographic highs, deflated zones, and sand availability. Additionally, changes in sand ridge occurrence and morphology may help explain changes in the long-term shoreline trends along Fenwick and Assateague Islands. Although the data presented here cannot quantitatively link sand ridges to sediment transport and shoreline change, it does present a compelling relationship between inner-shelf sand availability and movement, sand ridge occurrence and morphology, geologic framework, and shoreline behavior.

  17. Planet-wide sand motion on mars

    Science.gov (United States)

    Bridges, N.T.; Bourke, M.C.; Geissler, P.E.; Banks, M.E.; Colon, C.; Diniega, S.; Golombek, M.P.; Hansen, C.J.; Mattson, S.; McEwen, A.S.; Mellon, M.T.; Stantzos, N.; Thomson, B.J.

    2012-01-01

    Prior to Mars Reconnaissance Orbiter data, images of Mars showed no direct evidence for dune and ripple motion. This was consistent with climate models and lander measurements indicating that winds of sufficient intensity to mobilize sand were rare in the low-density atmosphere. We show that many sand ripples and dunes across Mars exhibit movement of as much as a few meters per year, demonstrating that Martian sand migrates under current conditions in diverse areas of the planet. Most motion is probably driven by wind gusts that are not resolved in global circulation models. A past climate with a thicker atmosphere is only required to move large ripples that contain coarse grains. ?? 2012 Geological Society of America.

  18. 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)

  19. On the Size Distribution of Sand

    DEFF Research Database (Denmark)

    Sørensen, Michael

    2016-01-01

    by Bagnold and confirmed in numerous empirical studies. The model implies that the size distribution of a sand deposit is a logarithmic normal-inverse Gaussian (NIG) distribution, which is one of the generalized hyperbolic distributions. The model modifies a previous model, which implied a log-normal size-distribution......, variance and skewness of the log-size distribution to the physical parameters of the model. The results might be useful when comparing empirical size-distributions from different deposits. It is argued that size-distributions with the same general shape as the NIG-distributions can be obtained also when......A model is presented of the development of the size distribution of sand while it is transported from a source to a deposit. The model provides a possible explanation of the log-hyperbolic shape that is frequently found in unimodal grain size distributions in natural sand deposits, as pointed out...

  20. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...

  1. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...

  2. Development tendencies of moulding and core sands

    Directory of Open Access Journals (Sweden)

    Stanislaw M. Dobosz1

    2011-11-01

    Full Text Available Further development of the technology for making moulding and core sands will be strictly limited by tough requirements due to protection of the natural environment. These tendencies are becoming more and more tense, so that we will reach a point when even processes, that from technological point of view fulfill high requirements of the foundry industry, must be replaced by more ecologically-friendly solutions. Hence, technologies using synthetic resins as binding materials will be limited. This paper presents some predictable development tendencies of moulding and core sands. The increasing role of inorganic substances will be noticed, including silicate binders with significantly improved properties, such as improved knock-out property or higher reclamation strength. Other interesting solutions might also be moulding sands bonded by geo-polymers and phosphate binders or salts and also binders based on degradable biopolymers. These tendencies and the usefulness of these binders are put forward in this paper.

  3. Sand transport, erosion and granular electrification

    DEFF Research Database (Denmark)

    Merrison, J.P.

    2012-01-01

    The transport of granular materials by wind has a major impact on our environment through sand/soil erosion and the generation and transport of atmospheric dust aerosols. Terrestrially the transport of dust involves billions of tons of material every year, influencing the global climate...... 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...

  4. Bioaugmentation of flow-through sand filters

    DEFF Research Database (Denmark)

    Samuelsen, Elin Djurhuus

    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...... coincided with efficient mineralisation/degradation, and proposed the tfdC gene as a suitable marker for monitoring phenoxy acid degradation in strain PM2. Furthermore, when testing strain PM2s degradation performance in flow-through sand columns, we found that strain PM2 was able to sustain induced...... 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...

  5. A Threshold Continuum for Aeolian Sand Transport

    Science.gov (United States)

    Swann, C.; Ewing, R. C.; Sherman, D. J.

    2015-12-01

    The threshold of motion for aeolian sand transport marks the initial entrainment of sand particles by the force of the wind. This is typically defined and modeled as a singular wind speed for a given grain size and is based on field and laboratory experimental data. However, the definition of threshold varies significantly between these empirical models, largely because the definition is based on visual-observations of initial grain movement. For example, in his seminal experiments, Bagnold defined threshold of motion when he observed that 100% of the bed was in motion. Others have used 50% and lesser values. Differences in threshold models, in turn, result is large errors in predicting the fluxes associated with sand and dust transport. Here we use a wind tunnel and novel sediment trap to capture the fractions of sand in creep, reptation and saltation at Earth and Mars pressures and show that the threshold of motion for aeolian sand transport is best defined as a continuum in which grains progress through stages defined by the proportion of grains in creep and saltation. We propose the use of scale dependent thresholds modeled by distinct probability distribution functions that differentiate the threshold based on micro to macro scale applications. For example, a geologic timescale application corresponds to a threshold when 100% of the bed in motion whereas a sub-second application corresponds to a threshold when a single particle is set in motion. We provide quantitative measurements (number and mode of particle movement) corresponding to visual observations, percent of bed in motion and degrees of transport intermittency for Earth and Mars. Understanding transport as a continuum provides a basis for revaluating sand transport thresholds on Earth, Mars and Titan.

  6. Sand control systems used in completing wells

    Directory of Open Access Journals (Sweden)

    Gabriel Wittenberger

    2005-12-01

    Full Text Available Expandable Tubular Technology is transforming the face of well completion and construction. This technology provides: a substantially higher hydrocarbon production rates from the reservoir, a reduced well drilling and construction costs, new possibilities for previously unreachable or uneconomic reservoirs, and step a change towards the single diameter well. ESS (Expandable Sand Screen has an unrivalled performance worldwide for delivering a reliable sand control in a wide range of applications. Well costs typically cut by over 20 %, and the productivity increases up to 70 %.

  7. Undrained Cyclic Behaviour of Dense Frederikshavn Sand

    DEFF Research Database (Denmark)

    Nielsen, Søren Kjær; Ibsen, Lars Bo; Sørensen, Kris Wessel

    2013-01-01

    A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series of undra......A modified contour diagram is created for the Frederikshavn Sand in the undrained case for a relative density of ID = 80 %. It can be used to estimate the number of cycles to failure for a given combination of pore pressure, average and cyclic load ratio. The diagram is based on a series...

  8. How confident is Fort McKay that industry can reclaim oil sand development

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, C. [Fort McKay First Nations, AB (Canada)

    2004-02-05

    This presentation described how traditional environmental knowledge (TEK) can provide valuable information for both the reclamation design and assessment of oil sand development in Fort McKay. Conservation is valued by the Fort McKay First Nations communities who claim that current reclamation methods are too slow, and that the land is not being brought back to its original use with the uniqueness of the boreal landscape. Elders have noted that each year the water level in the Athabasca River is lower. The blowing tailings and coke dust are causing trees to dye and driving animals away. There is concern that the animals that remain may not be safe to eat. The Fort McKay First Nation community has stated that it will view reclamation as a success only when it functions with proof over many generations. The major concerns include: salt in the water draining from reclaimed areas; salt in the soils of reclaimed area; muskeg cannot be recreated; and, the issue of whether cranberry, blueberry and streambank forest areas can be recreated, along with traditional medicinal plants. Other concerns include the loss of rivers such as the Beaver Creek and Tar River, and that the water in reclaimed areas may not be suitable for animals to live in or to drink. tabs., figs.

  9. An evaluation of sand and gravel resources in and near the Prescott National Forest in the Verde Valley, Arizona; with a section on evaluation of sand and gravel resources using selected engineering variables

    Science.gov (United States)

    Cox, Leslie J.; Bliss, James D.; Miller, Robert J.

    1999-01-01

    This study was based on available published literature. Although no field investigation was conducted in the Prescott National Forest to the west of the Verde River, a field investigation was conducted in the summer of 1994 by this author on the Coconino National Forest, to the east of the Verde River, where units of surficial materials of the same age and similar character are found (Cox, 1995). The intent of this evaluation of sand and gravel resources in the Prescott National Forest and adjacent areas in the Verde Valley, is to provide the land managers of the U.S. Forest Service with a map that delineates sand- and gravel-bearing geologic units. The map distinguishes (1) sand-and gravel-bearing units that are limited to channels from those that are not, (2) sand-and gravel-bearing units that are thin (generally less than 40 feet thick which is one contour interval on the topographic maps) from those that are locally thick (generally 40 feet or more), (3) sand- and gravel-bearing units that are poorly sorted from those that are well-sorted4, (4) sand- and gravel-bearing units that have little or no soil development from those that have greater degrees of soil development and lithification, (5) and sand- and gravel-bearing units that support riparian vegetation from those that do not. These distinctive characteristics are related to the geologic age or depositional setting of the rock materials and can be distinguished where areas are mapped in detail.

  10. Sand dunes - a study of the different dune formations in the Namib Sand Sea, Namibia

    Science.gov (United States)

    Sangunji, Antonio

    2017-04-01

    Sand dunes - a study of the different dune formations in the Namib Sand Sea, Namibia By: Antonio Sangunji, Academia Secondary School, Windhoek, Namibia The Namib Sand Sea has spectacular dunes, some of which are 5700 years old. Large, complex, linear dune in the northern part of the Namib Sand Sea provide new information on the age and internal sedimentary structures of these dunes, with important implications for interpretations of paleoclimates and the rock record of eolian sandstones. Academia Secondary School learners study several science subjects including Life and Physical sciences. As part of their Science course, they study the environment and landforms. To better understand the dune dynamics, several grade 8 pupils, 35 learners in total were taken to the field to demonstrate the formation of dunes. One of the highest points in the Namib Sand Sea - Dune 7 which is 388 meters was visited. Learners made models of the dunes in the classroom with different types of modeling clay, such as oil-based, polymer, dough and pottery clay. The learners also carried out hands-on exercises on the link between different types of sand, wind speed, size and altitude of the dunes. Field trips are a great opportunity for learners to learn how sand dunes are formed and show how simple experiments can be used to demonstrate dune formation.

  11. Composition and Dissolution of a Migratory, Weathered Coal Tar Creosote DNAPL

    Directory of Open Access Journals (Sweden)

    Kerstin E. Scherr

    2016-09-01

    Full Text Available Opaque, viscous tars derived from the carbonization of fossile carbon feedstocks, such coal tars and creosote, are long-term sources of groundwater contamination, predominantly with poly- and heterocyclic aromatic hydrocarbons (PAH. The dissolution, ageing and migratory behavior of dense, non aqueous phase liquid (DNAPL coal tar blobs and pools forming at the aquitard is not sufficiently understood to estimate the risk and adequately design groundwater treatment measures at a contaminated site. In this study, we investigate the composition and dissolution of a migrated, aged creosote DNAPL and corresponding experimental and groundwater profiles using comprehensive two-dimensional gas chromatography (GCxGC-MS. GC-FID unresolved compounds were attributed to methylated homocyclic species using GCxGC-MS in the Methylanthracene weight range. Equilibrium concentrations were estimated using Raoult’s law, assuming non-ideal behavior. Low molecular weight compounds were found to be prevalent even after decades of weathering, with Naphthalene (8% by mass representing the most abundant identified compound, contrary to the expected preferential depletion of hydrophilic compounds. Morevoer, dimethylnaphthalenes were relatively more abundant in the aqueous boundary layer than in the DNAPL. DNAPL migration over 400m with the groundwater flow effected lower viscosity and specific gravity of the migrated phase body in a superposition of weathering, transport and aquifer chromatography effects. Based on a decomposition of analysed and estimated constituents using the group contribution approach, reference DNAPL values for activity coefficients γi were used to model aqueous solubilities for selected compounds. Anthracene was close to its theoretical precipitation limit in the bulk DNAPL. While laboratory and modelled DNAPL dissolution behavior agree well, field data imply the presence of specific interfacial in situ processes significantly impacting dissolution

  12. Biomass waste gasification - can be the two stage process suitable for tar reduction and power generation?

    Science.gov (United States)

    Sulc, Jindřich; Stojdl, Jiří; Richter, Miroslav; Popelka, Jan; Svoboda, Karel; Smetana, Jiří; Vacek, Jiří; Skoblja, Siarhei; Buryan, Petr

    2012-04-01

    A pilot scale gasification unit with novel co-current, updraft arrangement in the first stage and counter-current downdraft in the second stage was developed and exploited for studying effects of two stage gasification in comparison with one stage gasification of biomass (wood pellets) on fuel gas composition and attainable gas purity. Significant producer gas parameters (gas composition, heating value, content of tar compounds, content of inorganic gas impurities) were compared for the two stage and the one stage method of the gasification arrangement with only the upward moving bed (co-current updraft). The main novel features of the gasifier conception include grate-less reactor, upward moving bed of biomass particles (e.g. pellets) by means of a screw elevator with changeable rotational speed and gradual expanding diameter of the cylindrical reactor in the part above the upper end of the screw. The gasifier concept and arrangement are considered convenient for thermal power range 100-350 kW(th). The second stage of the gasifier served mainly for tar compounds destruction/reforming by increased temperature (around 950°C) and for gasification reaction of the fuel gas with char. The second stage used additional combustion of the fuel gas by preheated secondary air for attaining higher temperature and faster gasification of the remaining char from the first stage. The measurements of gas composition and tar compound contents confirmed superiority of the two stage gasification system, drastic decrease of aromatic compounds with two and higher number of benzene rings by 1-2 orders. On the other hand the two stage gasification (with overall ER=0.71) led to substantial reduction of gas heating value (LHV=3.15 MJ/Nm(3)), elevation of gas volume and increase of nitrogen content in fuel gas. The increased temperature (>950°C) at the entrance to the char bed caused also substantial decrease of ammonia content in fuel gas. The char with higher content of ash leaving the

  13. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management.

    Science.gov (United States)

    Mahler, Barbara J; Metre, Peter C Van; Crane, Judy L; Watts, Alison W; Scoggins, Mateo; Williams, E Spencer

    2012-03-20

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments-including stormwater runoff, lake sediment, soil, house dust, and most recently, air-contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  14. You're standing on it! Coal-tar-based pavement sealcoat and environmental and human health

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.

    2013-01-01

    Coal-tar-based sealcoat—a product marketed to protect and beautify asphalt pavement—is a potent source of polycyclic aromatic hydrocarbons (PAHs) to air, soils, streams and lakes, and homes. Does its use present a risk to human health?

  15. Biomass Waste Gasification – Can Be the Two Stage Process Suitable for Tar Reduction and Power Generation?

    Czech Academy of Sciences Publication Activity Database

    Šulc, J.; Štojdl, J.; Richter, M.; Popelka, J.; Svoboda, Karel; Smetana, J.; Vacek, J.; Skoblia, S.; Buryan, P.

    2012-01-01

    Roč. 32, č. 4 (2012), s. 692-700 ISSN 0956-053X Grant - others:RFCR(XE) CT-2010-00009 Institutional research plan: CEZ:AV0Z40720504 Keywords : waste biomass * gasification * tar Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use Impact factor: 2.485, year: 2012

  16. Are PAHS the Right Metric for Assessing Toxicity Related to Oils, Tars, Creosote and Similar Contaminants in Sediments?

    Science.gov (United States)

    Oils, tars, and other non-aqueous phase hydrocarbon liquids (NAPLs) are common sources of contamination in aquatic sediments, and the toxicity of such contamination has generally been attributed to component chemicals, particularly PAHs. While there is no doubt PAHs can be toxic ...

  17. Genetic variation in thrombin-activatable fibrinolysis inhibitor (TAR) is associated with the risk of splanchnic vein thrombosis

    NARCIS (Netherlands)

    de Bruijne, Emile L. E.; Murad, Sarwa Darwish; de Maat, Moniek P. M.; Tanck, Michael W. T.; Haagsma, Elizabeth B.; van Hoeks, Bart; Rosendaal, Frits R.; Janssen, Harry L. A.; Leebeek, Frank W. G.

    Splanchnic vein thrombosis (SVT) has been associated with a hypercoagulable state. Thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to a hypercoagulable state, and therefore we were interested in the role of TAR in SVT. Since the disease is frequently associated with liver

  18. Coal-tar-based pavement sealcoat and PAHs: implications for the environment, human health, and stormwater management

    Science.gov (United States)

    Mahler, Barbara J.; Van Metre, Peter C.; Crane, Judy L.; Watts, Alison W.; Scoggins, Mateo; Williams, E. Spencer

    2012-01-01

    Coal-tar-based sealcoat products, widely used in the central and eastern U.S. on parking lots, driveways, and even playgrounds, are typically 20-35% coal-tar pitch, a known human carcinogen that contains about 200 polycyclic aromatic hydrocarbon (PAH) compounds. Research continues to identify environmental compartments—including stormwater runoff, lake sediment, soil, house dust, and most recently, air—contaminated by PAHs from coal-tar-based sealcoat and to demonstrate potential risks to biological communities and human health. In many cases, the levels of contamination associated with sealed pavement are striking relative to levels near unsealed pavement: PAH concentrations in air over pavement with freshly applied coal-tar-based sealcoat, for example, were hundreds to thousands of times higher than those in air over unsealed pavement. Even a small amount of sealcoated pavement can be the dominant source of PAHs to sediment in stormwater-retention ponds; proper disposal of such PAH-contaminated sediment can be extremely costly. Several local governments, the District of Columbia, and the State of Washington have banned use of these products, and several national and regional hardware and home-improvement retailers have voluntarily ceased selling them.

  19. TAR (Theatre as Representation) as a Provocative Teaching Tool in School Administration: A Dramatized Inclusive Classroom Scenario

    Science.gov (United States)

    Meyer, Matthew J.; Young, David C.

    2013-01-01

    The following dramatized classroom scenario depicts a teacher struggling with the nature of an inclusive learning environment, with instructional leadership and supervision of instruction as the theoretical and practical backdrop. The purpose of this article is to demonstrate how the use of a TAR (theatre as representation) case study can be used…

  20. Johannes Hindi tütar Pille Pae : inimlik headus ei sõltu rezhiimist / Pille Pae ; interv. Anneli Ammas

    Index Scriptorium Estoniae

    Pae, Pille

    2006-01-01

    Desintegraatori juhi Johannes Hindi tütar Pille Pae vastab küsimustele, mis puudutavad tema isa armuandmispalve esitamist, isale toetusallkirjade kogumist ning Arnold Rüütli suhteid Johannes Hindiga. Lisa: Kes oli Johannes Hint ja mis Desintegraator?

  1. Tat-dependent production of an HIV-1 TAR-encoded miRNA-like small RNA

    NARCIS (Netherlands)

    Harwig, Alex; Jongejan, Aldo; van Kampen, Antoine H. C.; Berkhout, Ben; Das, Atze T.

    2016-01-01

    Evidence is accumulating that retroviruses can produce microRNAs (miRNAs). To prevent cleavage of their RNA genome, retroviruses have to use an alternative RNA source as miRNA precursor. The transacting responsive (TAR) hairpin structure in HIV-1 RNA has been suggested as source for miRNAs, but how

  2. Analytical aspects of the remediation of soil by wet oxidation - Characterisation of tar contaminants and their degradation products

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Nielsen, T.; Plöger, A.

    1999-01-01

    Wet oxidation of tar compounds gives rise to a wide range of products. Due to the incorporation of oxygen, these products become increasingly more water soluble and the analytical strategy has to take into account the different physical/chemicalproperties of the compounds. An interplay between gas...

  3. A hydrophobic ammonia-oxidizing archaeon of the Nitrosocosmicus clade isolated from coal tar-contaminated sediment

    NARCIS (Netherlands)

    Jung, Man-Young; Kim, Jong-Geol; Sinninghe Damsté, Jaap S; Rijpstra, W Irene C; Madsen, Eugene L; Kim, So-Jeong; Hong, Heeji; Si, Ok-Ja; Kerou, Melina; Schleper, Christa; Rhee, Sung-Keun

    2016-01-01

    A wide diversity of ammonia-oxidizing archaea (AOA) within the phylum Thaumarchaeota exists and plays a key role in the N cycle in a variety of habitats. In this study, we isolated and characterized an ammonia-oxidizing archaeon, strain MY3, from a coal tar-contaminated sediment. Phylogenetically,

  4. Operating sand and environment: can harmonising?

    Directory of Open Access Journals (Sweden)

    Eriton Geraldo Vieira

    2015-12-01

    Full Text Available Mining is considered one of the basic sectors of Brazil's economy. The mining activity provides basic raw material for industry, and several products from the simplest to the most complex have mineral origin. Most products mined in Brazil, by volume, are sand and crushed stone. The sand extraction activities are of great importance for social development, but equally responsible for negative environmental impacts, sometimes irreversible. Due to the location’s rigidity, the sand miner is forced to mine where there is mineral occurrence, which constantly is near the bottom of valleys and rivers, often coinciding with the riparian forests, which are considered to be permanently protected areas (APP. In this context, objective is to demonstrate through a dialectical approach, procedurally developed through literature the possibility of conciliating the exploration of ore sand in permanently protected areas. Thus, will be analyzed the rules established in the Law 12.651/12 (New forest law, as well as will be demonstrated the socioeconomic and environmental impacts of mining activities which have to be observed to achieve the environmental function of property. The research was supported by the qualitative method and its construction we used the technique of bibliographical and documentary review.

  5. A Triaxial Characteristic State Model for Sand

    DEFF Research Database (Denmark)

    Krenk, S.; Borup, M.; Hedegaard, J.

    A non-associated plasticity model for sand is presented. The loading surface is a closed two-parameter surface in the principal stress space, determined by a size and a shape parameter. The shape parameter is determined explicitly from the slope of the characteristic line. For small mean stress...

  6. Sublittoral sand dollar (Echillodiscus bisperforatus) communities in ...

    African Journals Online (AJOL)

    *To whom cnrrespondence should he addressed. **Prc~cnt Jddrcss: Sea hsheries Research Institute, Privsand communities and a numher of morphologically simi- lar species inhabit a variety of relatively sheltered habitats.

  7. Our Footprints on the Sands of Time

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 1. Our Footprints on the Sands of Time. Partha P Majumder D Balasubramanian. General Article Volume 11 Issue 1 January 2006 pp 32-50. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. experimental investigation of sand minimum transport velocity

    African Journals Online (AJOL)

    user

    The production of reservoir fluid through long tiebacks/pipelines has emerged as one of the cost effective alternative especially for many marginal fields which can now be produced as clusters into a common processing facility. However, sand is often co-produced with the reservoir fluid especially when produced from ...

  9. Fatal toxoplasmosis in sand cats (Felis margarita).

    Science.gov (United States)

    Pas, An; Dubey, J P

    2008-09-01

    The sand cat (Felis margarita) is a small-sized felid occurring in the United Arab Emirates (UAE). The sand cat captive-breeding program at the Breeding Centre for Endangered Arabian Wildlife in Sharjah, UAE, has until recently been severely compromised by very high newborn mortality rates. Two different pairs of sand cats gave birth, respectively, to one and two litters (with a total of eight kittens) between 1999 and 2006. Seven out of eight kittens died between the third and 21st wk of life. Toxoplasmosis was confirmed as the cause of death in these two litters. Adult cats had high antibody titers to Toxoplasma gondii before pregnancy, suggesting that maternal immunity did not protect the kittens against infection with T. gondii and that maternal immunity might not have prevented transplacental transmission of the parasite. This observation contrasts with what is seen in domestic cats. To date, this is the first report on confirmed fatal toxoplasmosis and prevalence of T. gondii in sand cats.

  10. V-2 Rocket at White Sands

    Science.gov (United States)

    1946-01-01

    A V-2 rocket takes flight at White Sands, New Mexico, in 1946. The German engineers and scientists who developed the V-2 came to the United States at the end of World War II and continued rocket testing under the direction of the U. S. Army, launching more than sixty V-2s.

  11. Sublittoral sand dollar ( Echinodiscus bisperforatus ) communities in ...

    African Journals Online (AJOL)

    Macrofauna, meiofauna and sediment parameters together with sand dollar abundance and distribution were recorded along transects with stations at 2 m depth intervals from 4 m to 12 m. A wave-induced, depth-related turbulence gradient was evident with both mean particle size and sediment sorting decreasing with ...

  12. Soil and humus development in drift sands

    NARCIS (Netherlands)

    Sevink, J.; de Waal, R.W.; Fanta, J.; Siepel, H.

    2010-01-01

    In drift sand, incipient mineral soils with a very thin endorganic horizon develop towards highly acid soils with a thick, differentiated, mor to moder type ectorganic horizon and incipient podzolisation, within a period of about 100 years. This is due slow litter decomposition and associated soil

  13. Undrained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    of frictional materials during monotonic loading. The tests conducted includes undrained and constant volume tests, starting from different initial states of stress and following various stress paths. All the tests are performed on reconstituted loose to medium dense specimens of Eastern Scheldt Sand....

  14. HuMiTar: A sequence-based method for prediction of human microRNA targets

    Directory of Open Access Journals (Sweden)

    Chen Ke

    2008-12-01

    Full Text Available Abstract Background MicroRNAs (miRs are small noncoding RNAs that bind to complementary/partially complementary sites in the 3' untranslated regions of target genes to regulate protein production of the target transcript and to induce mRNA degradation or mRNA cleavage. The ability to perform accurate, high-throughput identification of physiologically active miR targets would enable functional characterization of individual miRs. Current target prediction methods include traditional approaches that are based on specific base-pairing rules in the miR's seed region and implementation of cross-species conservation of the target site, and machine learning (ML methods that explore patterns that contrast true and false miR-mRNA duplexes. However, in the case of the traditional methods research shows that some seed region matches that are conserved are false positives and that some of the experimentally validated target sites are not conserved. Results We present HuMiTar, a computational method for identifying common targets of miRs, which is based on a scoring function that considers base-pairing for both seed and non-seed positions for human miR-mRNA duplexes. Our design shows that certain non-seed miR nucleotides, such as 14, 18, 13, 11, and 17, are characterized by a strong bias towards formation of Watson-Crick pairing. We contrasted HuMiTar with several representative competing methods on two sets of human miR targets and a set of ten glioblastoma oncogenes. Comparison with the two best performing traditional methods, PicTar and TargetScanS, and a representative ML method that considers the non-seed positions, NBmiRTar, shows that HuMiTar predictions include majority of the predictions of the other three methods. At the same time, the proposed method is also capable of finding more true positive targets as a trade-off for an increased number of predictions. Genome-wide predictions show that the proposed method is characterized by 1.99 signal

  15. Dark grains of sand: a geological storytelling

    Science.gov (United States)

    Gallo Maresca, Magda

    2017-04-01

    In the secondary Italian school the Earth science learning begins at first year, in synergy with other natural science subjects such as Astronomy, Chemistry and Biology. Italian teachers have to focus on the landscape geomorphological aspects and often Earth processes are difficult to display since they are related to certain phenomena happened during the past and often far from the involved country. In order to better understand the environment surrounding us, very simple and poor materials, like sands, allow the teachers to create attractive lab experiences. According to the IBSE (Inquiry Based Science Education) approach, a learning unit has been implemented starting from a walking along the light carbonate beaches of the Adriatic sea: a smart look to the sands ("engage step"), stroke the students fantasy pushing them to explore some strange black grains on the sands. Dirty sands? Or rock landscape, soil degradation and Ofanto river and coastal processes (erosion, transportation and deposition)? This was the teaching challenge. Due to the youngest age, a third level, guided inquiry, was adopted so the teacher is the "guide of inquiry" encouraging the students using the research question ("Why is the sand dark?", "Do all sands look the same?", "Where does it come from?") and driving the students around their investigation plans ("How can I measure grain size?"). A procedure to answer the above questions and validate the results and explanations has been implemented to allow the students to be proactive in their study. During the learning activities will be the students to ask for field trip to elaborate their new knowledge, verify and visualize the speculated processes. The teaching skills allow to address several geosciences domains such as mineralogy, petrology, regional geology and geodynamics as well as other scientific disciplines such as mathematics (more specifically statistics), forensic science and even life sciences (the presence of bioclasts might

  16. West Nile Virus

    Science.gov (United States)

    ... of Whether Lower Respiratory Tract Infections Improve with Antibacterial Treatment , February 13, 2018 NIH Scientists Adapt New ... ecological patterns in the United States, and insecticide resistance. Read more about West Nile virus biology, genetics ...

  17. US west coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerial surveys are conducted along the US west coast to determine distribution and abundance of endangered leatherback turtles (Dermochelys coriacea), loggerhead...

  18. Wind regime and sand transport in China's Badain Jaran Desert

    Science.gov (United States)

    Zhang, Zhengcai; Dong, Zhibao; Li, Chunxiao

    2015-06-01

    Wind controls the formation and development of aeolian dunes, therefore understanding the wind environment is necessary in aeolian dune research. In recent years, climate has changed in and around the Badain Jaran Desert, and the factors that control aeolian dune development have changed with it. In this paper, we analyzed characteristics of the desert's wind regime based on data from seven weather stations in and around the desert. The temporal and spatial variation in the wind regime's characteristics have different effects on dune formation and development. The annual mean wind velocity, maximum wind velocity, and the proportion of the time the wind exceeded the sand-entrainment threshold are largest at the northern margin of the desert, and these values decrease from north to south and from east to west. The dominant winds are from the northwest, northeast, and southwest. The drift potential (DP) in the desert decreases from north to south, and can be divided into three regions: high in the north, intermediate in the central region, and low in the south. The effects of climate change on the calculated DP will be complex; although DP increased with increasing mean wind velocity and temperature, there was little or no relationship with precipitation and relative humidity.

  19. 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.

  20. Triaxial and Torsional Shear Test Results for Sand

    Science.gov (United States)

    1994-06-01

    Hettler & Vardoulais Compression Behavior of dry sand (1994)__ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Vaid & Chem (1985) Cyclic...1, 2 and 3, ELE Internationa Limited, 1985. Hettler , A. W., and Vardoulakis, I., "Behavior of Dry Sand Tested in a Larger Triaxial Apparatus

  1. Fiber-reinforced sand strength and dilation characteristics

    Directory of Open Access Journals (Sweden)

    Hesham M. Eldesouky

    2016-06-01

    Full Text Available Randomly distributed fiber reinforcement is used to provide an isotropic increase in the sand shear strength. The previous studies were not consistent regarding the fibers effect on the volumetric change behavior of fiber-reinforced sand. In this paper, direct shear tests are conducted on 108 specimens to investigate the effects of the fibers content, relative density, normal stress and moisture content on the shear strength and volumetric change behaviors of fiber-reinforced sand. The study investigates also the possibility of using dry fiber-reinforced sand as an alternative to heavily compacted unreinforced moist sand. The results indicate that the fibers inclusion increases the shear strength and dilation of sand. Moisture suppresses the fibers effect on the peak and post-peak shear strengths, and dilation. Dry loose fiber-reinforced sand achieves the same shear strength of heavily compacted unreinforced moist sand, yet at more than double the horizontal displacement.

  2. Mineral resource of the month: industrial sand and gravel

    Science.gov (United States)

    Dolley, Thomas

    2007-01-01

    With many diverse uses, industrial sand and gravel, also known as silica sand, is one of the most important nonmetallic minerals in the world. Industrial sand and gravel is a mining industry term used for sands that have a very high percentage of silicon dioxide, or greater than 95 percent quartz. Deposits of industrial sand and gravel can be found virtually everywhere on Earth, but are less widespread than deposits of common construction sand and gravel. Industrial sand and gravel is distinctive in grain size, hardness, inertness and resistance to high temperature and chemical action. Beverage containers, fiberglass insulation, fiber-optic cables and light bulbs are just some of today’s many products produced from industrial sand and gravel.

  3. Study on non-isothermal kinetics for modified coal tar pitch

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.; Shui, H.; Feng, Y. [East China Institute of Metallurgy, Maanshan (China). Dept of Chemical Engineering

    2001-04-01

    The non-isothermal kinetics for the mesophase transformation of Baogang-I coal tar pitch (I-CTP), soft pitch consisted of I-CTP and 18% phenanthrene residue oil (PRO) or I-CTP and 30% PRO have been studied in a thermal conversion unit. Kinetic parameters were calculated by using and integral method. Results showed that the process of mesophase pitch transformation could be described in first order reaction. The activation energy of I-CTP is 175.36 kJ/mol. But adding 30% PRO, which improved the reactivity of I-CTP with activation energy 138.07 kJ/mol, is not beneficial to the mesophase transformation. 7 refs., 2 figs., 6 tabs.

  4. Study of the Carbonization and Graphitization of Coal Tar Pitch Modified with SiC Nanoparticles

    Directory of Open Access Journals (Sweden)

    Maciej Gubernat

    2017-01-01

    Full Text Available Silicon carbide nanoparticles (nSiC have been used to modify coal tar pitch (CTP as a carbon binder. The influence of ceramic nanoparticles on the structure and microstructure was studied. The structure of CTP-based carbon residue with various nSiC contents was analyzed by using SEM with EDAX, Raman spectroscopy, and X-ray diffraction. The effect of ceramic nanofiller on the crystallite sizes (Lc, La and the c-axis spacing (d002 in carbonized samples after heating from 1000 to 2800°C was analyzed. Ceramic nanofillers inhibit structural changes in carbonized samples heated to 1000°C. After heating CTP with nSiC above 2000°C, the carbon samples contained two carbon components differing in structural ordering. Ceramic nanoparticles increase carbon crystallite growth, while their impact on the c-axis spacing is low.

  5. Rastislav Šuštaršič and current issues of standard Slovene language

    Directory of Open Access Journals (Sweden)

    Vesna Požgaj Hadži

    2017-12-01

    Full Text Available By studying languages in contact, we can observe one language while revealing hidden features of another. This was the original idea of the two Slovene-Croatian phonetic and phonological bilateral projects, which connected various Slovene and Croatian phonologists. This paper highlights the work of Rastislav Šuštaršič, who continued his contrastive research of English and Slovene in contact within these projects. Several open issues of the Slovene standard language were also at the centre of his research interests, including the issue of tonemic accent in Slovene, which he studied mainly in collaboration with H. Tivadar. The findings of their works underlined a gap between the explicit norm and language use, which future codifiers of the Slovene standard language should take into consideration.

  6. Investigation of bonding mechanism of coking on semi-coke from lignite with pitch and tar

    Energy Technology Data Exchange (ETDEWEB)

    Vedat Arslan [Dokuz Eylul University, Izmir (Turkey). Engineering Faculty

    2006-10-15

    In coking, the bonding ability of inert macerals by reactive macerals is dependent on various parameters and also is related to the wettability of the inert macerals. In this study, the effect of carbonization temperature on the wettability of semi-cokes produced at various temperatures has been investigated. Soma and Yatagan semicokes represent inert macerals, and pitch was used as a reactive structure in the experiments. The briquetted pitch blocks were located on the semi-cokes and heated from the softening temperature of pitch (60{sup o}C) to 140{sup o}C to observe the wettability. In addition, liquid tar was also used to determine the wettability of semi-cokes. From the standpoint of wettability, the temperature of 900{sup o}C was determined to be the critical point for coke produced from sub-bituminous coals. 15 refs., 6 figs., 2 tabs.

  7. tt¯ $tar t$ pair production cross section measurement at the LHC

    Directory of Open Access Journals (Sweden)

    Kim Tae Jeong

    2012-06-01

    Full Text Available Measurement of tt¯ $tar t$ pair production cross sections with an integrated luminosity of around 1 fb−1 at √s = 7 TeV obtained with the ATLAS and CMS detectors are reported. The inclusive cross sections in dilepton (ee, eμ, μμ and μτ, lepton+jets (e, μ and all hadronic decay modes are measured. In addition to inclusive cross section measurement, the study of jet multiplicity with additional jets are also presented, which is important to constrain the initial state radiation. Measurement of the charge asymmetry at the LHC is also presented. All measurements are compatible with Standard Model predictions.

  8. Incipient Motion of Sand and Oil Agglomerates

    Science.gov (United States)

    Nelson, T. R.; Dalyander, S.; Jenkins, R. L., III; Penko, A.; Long, J.; Frank, D. P.; Braithwaite, E. F., III; Calantoni, J.

    2016-12-01

    Weathered oil mixed with sediment in the surf zone in the northern Gulf of Mexico after the 2010 Deepwater Horizon oil spill, forming large mats of sand and oil. Wave action fragmented the mats into sand and oil agglomerates (SOAs) with diameters of about 1 to 10 cm. These SOAs were transported by waves and currents along the Gulf Coast, and have been observed on beaches for years following the spill. SOAs are composed of 70%-95% sand by mass, with an approximate density of 2107 kg/m³. To measure the incipient motion of SOAs, experiments using artificial SOAs were conducted in the Small-Oscillatory Flow Tunnel at the U.S. Naval Research Laboratory under a range of hydrodynamic forcing. Spherical and ellipsoidal SOAs ranging in size from 0.5 to 10 cm were deployed on a fixed flat bed, a fixed rippled bed, and a movable sand bed. In the case of the movable sand bed, SOAs were placed both proud and partially buried. Motion was tracked with high-definition video and with inertial measurement units embedded in some of the SOAs. Shear stress and horizontal pressure gradients, estimated from velocity measurements made with a Nortek Vectrino Profiler, were compared with observed mobility to assess formulations for incipient motion. For SOAs smaller than 1 cm in diameter, incipient motion of spherical and ellipsoidal SOAs was consistent with predicted critical stress values. The measured shear stress at incipient motion of larger, spherical SOAs was lower than predicted, indicating an increased dependence on the horizontal pressure gradient. In contrast, the measured shear stress required to move ellipsoidal SOAs was higher than predicted, even compared to values modified for larger particles in mixed-grain riverine environments. The laboratory observations will be used to improve the prediction of incipient motion, transport, and seafloor interaction of SOAs.

  9. West African Journal of Medicine

    African Journals Online (AJOL)

    The West African Journal of Medicine is owned by the West African College of Physicians and the West African College of Surgeons. Aims: The aims of the Journal are: To provide a medium for international dissemination of information about medical science in West Africa and elsewhere. To furnish a means whereby ...

  10. Microscopic charcoal and tar (CHAT particles in peat: a 6500-year record of palaeo-fires in southern Sweden

    Directory of Open Access Journals (Sweden)

    B.A. Malmgren

    2012-01-01

    Full Text Available Peat stratigraphies of eleven raised bogs in southern Sweden were investigated. Measurements included the occurrence of charcoal and various tar particles. Most of the particles found were microscopic, i.e. 5–100 µm in diameter. Two distinctly different groups of particles were distinguished: (A charred fragments of plant tissue and (B objects formed from tar, which were classified into five sub-groups on the basis of morphology. Both charcoal and tar are indicative of mire and forest fires. We suggest that it is possible to use the different groups of particles as fire regime indicators. Hence, the high frequency of charcoal and tar (CHAT in the lower parts of the stratigraphies, i.e. in the lower strongly decomposed fen and carr peats that were formed before ca. 4000 cal 14C BP, could be indicative of intense and frequent local fires. The decreasing abundance of CHAT and the lower relative share of Type A particles within the lower strongly decomposed Sphagnum peat ca. 4000–2500 cal 14C BP signify a transition from local to regional fires. With a few exceptions, the uppermost weakly decomposed ombrotrophic peats formed after ca. 2500 cal 14C BP, in which both charcoal and tar are rare, indicate a period of low fire frequency at both local and regional scales. There is no regional variation in the lower material, and it seems that wildfires were common phenomena throughout southern Sweden during the first few thousand years after peat formation began 6–8000 years ago. From a climatological point of view, the mass occurrence of CHAT in the lower parts of the profiles indicates a warm and dry Mid Holocene with frequent and widespread wildfires, and a moist and cool Late Holocene with more sporadic fires. Spectral analysis of the entire dataset shows significant periodicities of 610, 70, 30, 21, 17 and 14 years, the two most significant being 14 and 70 years.

  11. Comprehensive GC²/MS for the monitoring of aromatic tar oil constituents during biodegradation in a historically contaminated soil.

    Science.gov (United States)

    Vasilieva, Viktoriya; Scherr, Kerstin E; Edelmann, Eva; Hasinger, Marion; Loibner, Andreas P

    2012-02-20

    The constituents of tar oil comprise a wide range of physico-chemically heterogeneous pollutants of environmental concern. Besides the sixteen polycyclic aromatic hydrocarbons defined as priority pollutants by the US-EPA (EPA-PAHs), a wide range of substituted (NSO-PAC) and alkylated (alkyl-PAC) aromatic tar oil compounds are gaining increased attention for their toxic, carcinogenic, mutagenic and/or teratogenic properties. Investigations on tar oil biodegradation in soil are in part hampered by the absence of an efficient analytical tool for the simultaneous analysis of this wide range of compounds with dissimilar analytical properties. Therefore, the present study sets out to explore the applicability of comprehensive two-dimensional gas chromatography (GC²/MS) for the simultaneous measurement of compounds with differing polarity or that are co-eluting in one-dimensional systems. Aerobic tar oil biodegradation in a historically contaminated soil was analyzed over 56 days in lab-scale bioslurry tests. Forty-three aromatic compounds were identified with GC²/MS in one single analysis. The number of alkyl chains on a molecule was found to prime over alkyl chain length in hampering compound biodegradation. In most cases, substitution of carbon with nitrogen and oxygen was related to increased compound degradation in comparison to unalkylated and sulphur- or unsubstituted PAH with a similar ring number.The obtained results indicate that GC²/MS can be employed for the rapid assessment of a large variety of structurally heterogeneous environmental contaminants. Its application can contribute to facilitate site assessment, development and control of microbial cleanup technologies for tar oil contaminated sites. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Cloning of the repertoire of individual Plasmodium falciparum var genes using transformation associated recombination (TAR.

    Directory of Open Access Journals (Sweden)

    Annette Gaida

    Full Text Available One of the major virulence factors of the malaria causing parasite is the Plasmodium falciparum encoded erythrocyte membrane protein 1 (PfEMP1. It is translocated to It the membrane of infected erythrocytes and expressed from approximately 60 var genes in a mutually exclusive manner. Switching of var genes allows the parasite to alter functional and antigenic properties of infected erythrocytes, to escape the immune defense and to establish chronic infections. We have developed an efficient method for isolating VAR genes from telomeric and other genome locations by adapting transformation-associated recombination (TAR cloning, which can then be analyzed and sequenced. For this purpose, three plasmids each containing a homologous sequence representing the upstream regions of the group A, B, and C var genes and a sequence homologous to the conserved acidic terminal segment (ATS of var genes were generated. Co-transfection with P. falciparum strain ITG2F6 genomic DNA in yeast cells yielded 200 TAR clones. The relative frequencies of clones from each group were not biased. Clones were screened by PCR, as well as Southern blotting, which revealed clones missed by PCR due to sequence mismatches with the primers. Selected clones were transformed into E. coli and further analyzed by RFLP and end sequencing. Physical analysis of 36 clones revealed 27 distinct types potentially representing 50% of the var gene repertoire. Three clones were selected for sequencing and assembled into single var gene containing contigs. This study demonstrates that it is possible to rapidly obtain the repertoire of var genes from P. falciparum within a single set of cloning experiments. This technique can be applied to individual isolates which will provide a detailed picture of the diversity of var genes in the field. This is a powerful tool to overcome the obstacles with cloning and assembly of multi-gene families by simultaneously cloning each member.

  13. Cloning of the repertoire of individual Plasmodium falciparum var genes using transformation associated recombination (TAR).

    Science.gov (United States)

    Gaida, Annette; Becker, Marion M; Schmid, Christoph D; Bühlmann, Tobias; Louis, Edward J; Beck, Hans-Peter

    2011-03-07

    One of the major virulence factors of the malaria causing parasite is the Plasmodium falciparum encoded erythrocyte membrane protein 1 (PfEMP1). It is translocated to It the membrane of infected erythrocytes and expressed from approximately 60 var genes in a mutually exclusive manner. Switching of var genes allows the parasite to alter functional and antigenic properties of infected erythrocytes, to escape the immune defense and to establish chronic infections. We have developed an efficient method for isolating VAR genes from telomeric and other genome locations by adapting transformation-associated recombination (TAR) cloning, which can then be analyzed and sequenced. For this purpose, three plasmids each containing a homologous sequence representing the upstream regions of the group A, B, and C var genes and a sequence homologous to the conserved acidic terminal segment (ATS) of var genes were generated. Co-transfection with P. falciparum strain ITG2F6 genomic DNA in yeast cells yielded 200 TAR clones. The relative frequencies of clones from each group were not biased. Clones were screened by PCR, as well as Southern blotting, which revealed clones missed by PCR due to sequence mismatches with the primers. Selected clones were transformed into E. coli and further analyzed by RFLP and end sequencing. Physical analysis of 36 clones revealed 27 distinct types potentially representing 50% of the var gene repertoire. Three clones were selected for sequencing and assembled into single var gene containing contigs. This study demonstrates that it is possible to rapidly obtain the repertoire of var genes from P. falciparum within a single set of cloning experiments. This technique can be applied to individual isolates which will provide a detailed picture of the diversity of var genes in the field. This is a powerful tool to overcome the obstacles with cloning and assembly of multi-gene families by simultaneously cloning each member.

  14. Mechanical characterization of Portland cement mortars containing petroleum or coal tar

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-08-01

    Full Text Available This article discusses experimental data on the flexural and compressive strength of Portland cement mortars containing additions or cement replacements consisting in petroleum or coal tar, by-products of the oil and coal industries. The materials studied were two coal (BACA and BACB and two petroleum (BPP and BPT tars. The results show that it is feasible to use such materials as a partial replacement for cement in mortar manufacture. This should lead to the design of a new sustainable product that will contribute to lowering the environmental impact of construction materials while at the same time opening up an avenue for the re-use of this type of industrial by-products.En este artículo se presentan datos experimentales de resistencia a flexión y a compresión de morteros de cemento Portland con adición y sustitución de breas de petróleo y de alquitrán de carbón, que son subproductos de la industria del carbón o del petróleo. Los materiales estudiados son breas de alquitrán de carbón A (BACA y B (BACB, y dos breas de petróleo (BPP y (BPT. Los datos demuestran la viabilidad del uso de estas breas en la fabricación de morteros con menores contenidos de cemento, permitiendo diseñar un nuevo material sostenible con el medio ambiente y que contribuya a reducir el impacto ambiental de los materiales de construcción, hecho que permite abrir una nueva vía de valorización de estos subproductos.

  15. Geochemical evidence for a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria

    Science.gov (United States)

    Bata, Timothy; Parnell, John; Samaila, Nuhu K.; Abubakar, M. B.; Maigari, A. S.

    2015-11-01

    Paleogeographic studies have shown that Earth was covered with more water during the Cretaceous than it is today, as the global sea level was significantly higher. The Cretaceous witnessed one of the greatest marine transgressions in Earth's history, represented by widespread deposition of sands directly on underlying basement. These sand bodies hold much of the world's heavy oil. Here, we present for the first time, geochemical evidence of a Cretaceous oil sand (Bima oil sand) in the Chad Basin, Nigeria. Bima oil sand is similar to other Cretaceous oil sands, predominantly occurring at shallow depths on basin flanks and generally lacking a seal cover, making the oil susceptible to biodegradation. The bulk properties and distribution of molecular features in oils from the Bima oil sand suggest that they are biodegraded. Sterane maturity parameters and the trisnorhopane thermal indicator for the oils suggest thermal maturities consistent with oils generated as conventional light oils, which later degraded into heavy oils. These oils also show no evidence of 25-norhopane, strongly suggesting that biodegradation occurred at shallow depths, consistent with the shallow depth of occurrence of the Bima Formation at the study locality. Low diasterane/sterane ratios and C29H/C30H ratios greater than 1 suggest a carbonate source rock for the studied oil. The Sterane distribution further suggests that the oils were sourced from marine carbonate rocks. The C32 homohopane isomerization ratios for the Bima oil sand are 0.59-0.60, implying that the source rock has surpassed the main oil generation phase, consistent with burial depths of the Fika and Gongila Formations, which are both possible petroleum source rocks in the basin.

  16. Advanced testing and characterization of transportation soils and bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2007-12-01

    Full Text Available Modulus with Hydrostatic Stress for Oil Sands at 30oC. .......... 79 FIGURE 4.7 Bulk Modulus Model 3 Performances for Oil Sand Samples at 20oC................... 82 FIGURE 4.8 Bulk Modulus Model 3 Performances for Oil Sand Samples at 30o... of Resilient Modulus with Applied Deviator Stress at Two Test Temperatures for AU-14 Sample............................................................................................. 140 FIGURE 6.15 Performances of the SE-09 Oil sand Sample Resilient...

  17. Research on the evaporation of gasoline on beach sand

    Energy Technology Data Exchange (ETDEWEB)

    Berqueiro, J.R.; Dominguez, F.; Pons, J.M

    Gasoline evaporation is an importent factor in spill behavour. When a gasoline spill occurs on beach sand, part of the gasoline is spread over the sand surface while the rest is being absorbed. The spread and absorption rate depend on, amoung other things, the permeability of the sand which in turn also depends on it's water content. It is important to study the effects of gasoline evaporation on sand beaches in order to determine when risk of explosion is low, so that cleaning of the polluted beach surface can be carried out without danger. The effects of the evaporation of 90 and 97 octane (normal and super) gasoline on beach sand have been studied using the tray evaporation technique as described in the literature. The size of the sand particles have been included along with temperature and air speed as variables in the evaporation process. The effects of gasoline on the retention capacity of three distinct types of sand particles, as well as the effects of water in the sand, have been studied for normal and super gasolines. The following conclusions can be drawn: sand retention capacity is inversely proportional to sand particle size; when sand is moistened, its gasoline retention capacity increases proportionally with the decreasing particle size; with the same sand fractions and air speed conditions; the evaporation rate increases with increasing air speeds; with the same sand fractions and air speed conditions the evaporation rate increases with temperature; given the same temperature and air conditions, a gasoline spill on coarse sand evaporates faster than one on medium sand; and given the same temperatures and air speed conditions, the evaporation rate of normal gasoline spreading over any of the three types of sand is always higher than super gasoline due to the higher volatility of the 90 octane gasoline. 10 refs., 1 fig., 3 tabs.

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

    African Journals Online (AJOL)

    User

    2015-03-18

    Mar 18, 2015 ... pilot scale up was carried out using 120 L (120,000 ml) of water from Mezam River pretreated with 2400 g of powdered M. oleifera seeds for 15 min retention time and filtered through a sand filter drum made of fine sand, coarse sand, charcoal and gravel for 1 h filtration time. The total mean values of ...

  19. Dewatering Behaviour of Fine Oil Sands Tailings : An Experimental Study

    NARCIS (Netherlands)

    Yao, Y.

    2016-01-01

    Oil sands tailings are a warm aqueous suspension of sand, silt, clay, residual bitumen and naphtha. The tailings are hydraulically transported and stored in tailing ponds where they segregate, with the sand settling from suspension forming beaches and the remaining tailings flowing to the middle of

  20. Design and Fabrication of a Foundry Sand Mixer Using Locally ...

    African Journals Online (AJOL)

    Most small foundry shops mix their sand manually which is not efficient since homogenous mix cannot be guaranteed and even when foundry mixer are available most of them are imported costing the nation huge foriegn exchange. A foundry sand mixer capable of mixing foundry sand has been designed and fabricated ...

  1. Dredging Processes I : The Cutting of Sand, Clay & Rock - Theory

    NARCIS (Netherlands)

    Miedema, S.A.

    2013-01-01

    This book gives an overview of cutting theories. It starts with a generic model, which is valid for all types of soil (sand, clay and rock) after which the specifics of dry sand, water saturated sand, clay, rock and hyperbaric rock are covered. For each soil type small blade angles and large blade

  2. Interactions between microbial activity and distribution and mineral coatings on sand grains from rapid sand filters treating groundwater

    DEFF Research Database (Denmark)

    Gülay, Arda; Tatari, Karolina; Musovic, Sanin

    Rapid sand filtration is a traditional and widespread technology for drinking water purification which combines biological, chemical and physical processes together. Granular media, especially sand, is a common filter material that allows several oxidized compounds to accumulate on its surface...

  3. Application of alkaliphilic biofilm-forming bacteria to improve compressive strength of cement-sand mortar.

    Science.gov (United States)

    Park, Sung-Jin; Chun, Woo-Young; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-03-01

    The application of microorganisms in the field of construction material is rapidly increasing worldwide; however, almost all studies that were investigated were bacterial sources with mineral-producing activity and not with organic substances. The difference in the efficiency of using bacteria as an organic agent is that it could improve the durability of cement material. This study aimed to assess the use of biofilm-forming microorganisms as binding agents to increase the compressive strength of cement-sand material. We isolated 13 alkaliphilic biofilmforming bacteria (ABB) from a cement tetrapod block in the West Sea, Korea. Using 16S RNA sequence analysis, the ABB were partially identified as Bacillus algicola KNUC501 and Exiguobacterium marinum KNUC513. KNUC513 was selected for further study following analysis of pH and biofilm formation. Cement-sand mortar cubes containing KNUC513 exhibited greater compressive strength than mineral-forming bacteria (Sporosarcina pasteurii and Arthrobacter crystallopoietes KNUC403). To determine the biofilm effect, Dnase I was used to suppress the biofilm formation of KNUC513. Field emission scanning electron microscopy image revealed the direct involvement of organic-inorganic substance in cement-sand mortar.

  4. Sand Needs and Resources Offshore New York

    Science.gov (United States)

    Lashley, J. M.; Flood, R. D.; White, M.; Bokuniewicz, H.; Hinrichs, C.; Wilson, R. E.

    2016-02-01

    "Superstorm" Sandy (October, 2012) accentuated the persistent problem of coastal erosion on New York's ocean coast. The New York state Department of State in cooperation with the Bureau of Ocean Energy Management has initiated further identification and assessment of marine sand reserves required to improve the resiliency of coastal communities and the maintenance of coastal habitats. The historical demand for beach nourishment has been about 1.5 million cubic meters per year, but sea level rise and the occurrence of extreme conditions may increase the demand to over 5 million cubic meters annually. Forty-four historical and proposed borrow sites have been delineated. This inner shelf is both sand rich and data rich. Geophysical and geological data has been compiled and reassessed to support identification, characterization, and delineation of sand resources for potential use in future coastal restoration, beach nourishment, and/or wetland restoration efforts. The South Shore of Long Island is composed in part by the Fire Island National Seashore. Holocene sand ridges extending at an oblique angle to the cross shore in the seaward direction. Borrow pits among the sand ridges, excavated were apparent in the most recent surveys and it appears that natural replenishment of offshore borrow areas has been occurring although the rates need to be determined in order to assess their sustainability. Not only is the area one of intense societal attention, but the use of this resource for coastal resilience must fit into a diverse framework marine spatial planning including not only traditional components, like commercial fishing, but also new factors like the siting of offshore wind-farms. To extend this assessment will include a recent survey, sponsored by the Bureau of Ocean Energy Management and the New York Department of State, providing approximately 700 km of geophysical survey lines located between 3 and 9 nautical miles offshore, and 46 geotechnical samples

  5. Radiographic parameters for diagnosing sand colic in horses

    Directory of Open Access Journals (Sweden)

    Egenvall Agneta

    2008-06-01

    Full Text Available Abstract Background Ingestion of sand can cause colic, diarrhoea and weight loss in horses, but these signs are unspecific and can have many other causes. The amount of sand that induces disease may vary between individuals. To avoid over-diagnosing, it is important to determine the amount of sand that can be found in horses without clinical signs of gastrointestinal disease. The aim of this study was to use previously suggested parameters for establishing a radiographic diagnosis of sand colic, and compare these findings between a sand colic group and a control group. Methods Abdominal radiographs were obtained in 30 horses with a complaint unrelated to the gastrointestinal tract. In addition, archived abdominal radiographs of 37 clinical cases diagnosed with sand impaction were investigated. The size of the mineral opacity indicative of sand in the abdomen was measured and graded according to a previously published protocol based on height and length. Location, homogeneity, opacity and number of sand accumulations were also recorded. Results Twenty out of 30 control horses (66% had one or more sand accumulations. In the present study; height, length and homogeneity of the accumulations were useful parameters for establishing a diagnosis of sand colic. Radiographically defined intestinal sand accumulation grades of up to 2 was a common finding in horses with no clinical signs from the gastrointestinal tract whereas most of the clinical cases had much larger grades, indicating larger sand accumulations. Conclusion Further work to establish a reliable grading system for intestinal sand content is warranted, but a previously proposed grading system based on measurements of height and length may be an alternative for easy assessment of sand accumulations in the meantime. The present study indicates that a grade 1 – 2 sand accumulation in the intestine is a frequent finding in horses. When working up a case with clinical signs from the

  6. Porosity and packing of Holocene river, dune, and beach sands

    Energy Technology Data Exchange (ETDEWEB)

    Atkins, J.E. (Conoco, Inc., Oklahoma City, OK (United States)); McBride, E.F. (Univ. of Texas, Austin (United States))

    1991-03-01

    The porosity and packing of 174 samples of well-sorted surficial and shallowly buried (to 17 m), unconsolidated Holocene sands were determined by point counting the upper surface of thin sections of epoxy-impregnated samples in reflected light. Average depositional porosity for 124 surficial beach sands, river point-bar and braid-bar sands, and eolian dune sands is between 40% and 58%. Beach sands exhibit an average packing value (contact index = CI) of 0.79, river sands an average IC of 0.91, and eolian dune sands an average CI of 1.02. Packing gets tighter with depth, but the authors found no decrease in porosity with depth for river and beach sands buried to 17 m. Thus, packing is more sensitive to small changes in fabric than is porosity. Beach sands typically contain 5.5% oversized pores (OSP), river sands 3.8% OSP, and eolian dune sands 4.0% OSP. Most OSP are packing defects rather than dissolution pores, although trapped air bubbles are common in some beach sands. OSP decrease linearly with depth to 17 m, our deepest sample. Extrapolation of our data indicates that they will be destroyed at a depth less than 100 m. Significant differences in porosity, oversized-pore, and packing values exist between most point-bar and braid-bar deposits and between two heavily sampled point bars, but no significant differences in these values exist when braid-bar sands are compared to other braid-bar sands. Sands form different beaches have significant differences in porosity, oversized pores, and packing. The average porosity is 46% for eolian ripple strata, 50% for grain-fall strata, and 51% for grain-flow strata. Ripple strata are tighter packed than grain-fall and grain-flow strata.

  7. Tar in road system wastes - bibliographic study - quick characterization methods; Le goudron dans les dechets du reseau routier - etude bibliographique - methodes de caracterisation rapides

    Energy Technology Data Exchange (ETDEWEB)

    Brazillet, C.; Domas, J.; Pepin, G.

    2001-12-15

    In the framework of the european regulations on the wastes management, the road structure wastes present a particularly problem because of the tar content and of the toxic associated polycyclic aromatic hydrocarbons. In order to chose the elimination or the valorization of these roads wastes, it is necessary to measure the tar content. After a presentation of the study objectives, a bibliographic study of the context, the challenges, the hydrocarbons, the tar characterization and the today situation of the french road network, the author presents the methods of PAH detection with a special attention on the well known methods: the PAK marker, the TSE and the toluene spot. (A.L.B.)

  8. West Europe Report

    Science.gov (United States)

    1987-04-02

    foregoing statement is valid: the building of fortifications is permitted in too few cases, and not often enough! In the INTERNATIONAL DEFENSE REVIEW ...RIM status—and so do not have any firm team relationships—are brought up to and kept at the desired level with, among other things, review ...to rise. But there are big differences between species. Ordinary mycorrhiza fungi such as sand boletus, kremla and milk caps already had very

  9. West African crystalline maculopathy.

    Science.gov (United States)

    Browning, David J

    2004-05-01

    To report new observations in West African crystalline maculopathy. Retrospective, observational case series. Three patients drawn from a private retina practice. Review of clinical charts and photographic studies. Distribution of intraretinal crystals and changes after laser photocoagulation, and history of ingesting foods typical in a West African diet but atypical for an American diet. All patients were older than 50 years, had diabetic retinopathy, ate green vegetables not found in American diets, and showed no deleterious effects of the crystals. Kola nut ingestion in 2 patients was remote and sparse, and was unknown in a third patient. The first 2 affected patients originating outside the Ibo tribe of Nigeria are reported. The pattern of retinal crystals can be changed, and the quantity of crystals reduced, by laser photocoagulation of associated diabetic retinopathy. West African crystalline retinopathy is distinguishable from other causes of crystalline retinopathy. It may reflect a component of the West African diet, seems to have diabetic retinopathy as a promoting factor via breakdown of the blood-retina barrier, and can be modified by laser photocoagulation of diabetic retinopathy. Increased awareness of the condition will allow physicians seeing West African immigrants to make the diagnosis and treat the patients appropriately.

  10. Post-liquefaction reconsolidation of sand.

    Science.gov (United States)

    Adamidis, O; Madabhushi, G S P

    2016-02-01

    Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

  11. Longshore sediment transport at Golden Sands (Bulgaria

    Directory of Open Access Journals (Sweden)

    Hristo Nikolov

    2006-09-01

    Full Text Available The paper presents the results of studies on the qualitative and quantitative features of the littoral drift at Golden Sands (Bulgaria, carried out jointly by Polish and Bulgarian researchers. The mathematical modelling of physical coastal processes took wave transformation (wave diffraction and refraction; the effects of shoaling and wave breaking and longshore sediment transport into account. The computations were carried out for the mean statistical annual wave climate, determined on the basis of IO BAS wave data, simulated using the WAM method from long-term Black Sea wind data. The results of sediment transport computations clearly show that its direction off the Golden Sands shore is from north to south.

  12. Drained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Praastrup, U.; Jakobsen, Kim Parsberg

    In the process of understanding and developing models for geomaterials, the stress-strain behaviour is commonly studied by performing triaxial tests. In the present study static triaxial tests have been performed to gain knowledge of the stress-strain behaviour of frictional materials during mono...... monotonic loading. The tests reported herein are all drained tests, starting from different initial states of stress and following various stress paths. AIl the tests are performed on reconstituted medium dense specimens of Eastern Scheldt Sand....

  13. Response to Oil Sands Products Assessment

    Science.gov (United States)

    2015-09-01

    indoors or leave the area to limit their exposure to toxic fumes. Specific information about the diluent added to an oil sands mixture of concern would...known as upgraders. These refineries essentially strip much of the carbon from the bitumen and produce a light synthetic crude oil (known as Syncrude...Minnesota’s new law, states: (Douglass, 2014) “ Essentially , there’s no meaningful regulation or requirements or standards for oil spill response for

  14. Energetic instability unjams sand and suspension.

    Science.gov (United States)

    Jiang, Yimin; Liu, Mario

    2004-10-01

    Jamming is a phenomenon occurring in systems as diverse as traffic, colloidal suspensions, and granular materials. A theory on the reversible elastic deformation of jammed states is presented. First, an explicit granular stress-strain relation is derived that captures many relevant features of sand, including especially the Coulomb yield surface and a third-order jamming transition. Then this approach is generalized, and employed to consider jammed magnetorheological and electrorheological fluids, again producing results that compare well to experiments and simulations.

  15. Mineralogy of Eolian Sands at Gale Crater

    Science.gov (United States)

    Achilles, C. N.; Vaniman, D. T.; Blake, D. F.; Bristow, T. F.; Rampe, E. B.; Ming, D. W.; Chipera, S. J.; Morris, R. V.; Morrison, S. M.; Downs, R. T.; hide

    2016-01-01

    The Mars Science Laboratory rover Curiosity has been exploring outcrop and regolith in Gale crater since August 6, 2012. During this exploration, the mission has collected 10 samples for mineralogical analysis by X-ray diffraction (XRD), using the CheMin instrument. The CheMin (Chemistry and Mineralogy) instrument on the Mars Science Laboratory rover Curiosity uses a CCD detector and a Co-anode tube source to acquire both mineralogy (from the pat-tern of Co diffraction) and chemical information (from energies of fluoresced X-rays). A detailed description of CheMin is provided in [1]. As part of the rover checkout after landing, the first sample selected for analysis was an eolian sand deposit (the Rocknest "sand shadow"). This sample was selected in part to characterize unconsolidated eolian regolith, but primarily to prove performance of the scoop collection system on the rover. The focus of the mission after Rocknest was on the consolidated sediments of Gale crater, so all of the nine subsequent samples were collected by drilling into bedrock com-posed of lithified sedimentary materials, including mudstone and sandstone. No scoop samples have been collected since Rocknest, but at the time this abstract was written the mission stands poised to use the scoop again, to collect active dune sands from the Bagnold dune field. Several abstracts at this conference outline the Bagnold dune campaign and summarize preliminary results from analyses on approach to the Namib dune sampling site. In this abstract we review the mineralogy of Rocknest, contrast that with the mineralogy of local sediments, and anticipate what will be learned by XRD analysis of Bagnold dune sands.

  16. Cyclic Triaxial Loading of Cohesionless Silty Sand

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2015-01-01

    To engineer efficient structures offshore, we need to extend our knowledge of soil response. Cyclic loading and high water pressure encountered offshore greatly influence cohesionless soil performance. Silty sand from Frederikshavn wind turbine farm was tested using single diameter height samples...... with lubricated, smooth boundary piston heads in a Danish triaxial apparatus. Samples were successfully subjected to loading histories of high complexity. Loading include high strains and stresses, post liquefaction response, transitioning through multiple densities and restoring initial soil properties after...

  17. Sorption of Arsenite onto Mackinawite Coated Sand

    Science.gov (United States)

    Gallegos, T. J.; Hayes, K. F.; Abriola, L. M.

    2004-05-01

    Arsenic contamination of groundwater is a widespread problem affecting aquifers in the United States as well as abroad. Recent strengthening of the US EPA MCL for arsenic has prompted the need for technology capable of removing both arsenite and arsenate from solution. Arsenite, the more toxic form of arsenic, is more difficult to remove from anoxic zones in the subsurface. Studies by others have demonstrated the affinity of some types of iron sulfides for arsenite, such as troilite, pyrite, amorphous iron sulfide and mackinawite. However, these studies have not provided a comprehensive investigation of the macroscopic behavior of arsenite in the presence of crystalline mackinawite in a form that can be readily applied to real-world treatment technologies. This study examines the behavior of arsenite in the presence of mackinawite coated sand. PH edge results demonstrate that arsenite sorption onto mackinawite coated sand increases with increasing pH, reaching maximum removal at pH 10. Arsenite removal, albeit slight, occurring below pH 5 is independent of pH indicative of a different removal mechanism. Isotherm studies show that at low concentrations, removal is Langmuirian in nature. Arsenite sorption abruptly converts to linear behavior at high concentrations, possibly attributed to the saturation of the monolayer. Ionic strength effects were assessed by comparing pH edge data developed for three different concentrations of NaCl background electrolyte solution. Increases in ionic strength enhance the removal of arsenite from solution, suggesting possible inner-sphere surface complexation removal mechanisms. Information gathered in this study can be used to further develop surface complexation models to describe and predict reactivity of arsenite in the presence of mackinawite coated sands in anoxic regions. Mackinawite coated sands investigated here may provide a feasible reactive medium for implementation in above-ground sorption reactors or subsurface

  18. Fusion of arkosic sand by intrusive andesite

    Science.gov (United States)

    Bailey, Roy A.

    1954-01-01

    An andesite dike in the Valles Mountains of northern New Mexico has intruded and partly fused arkosic sediments for a distance of 50 feet from its contacts. The dike is semi-circular in form, has a maximum width of about 100 feet, and is about 500 feet long. Small associated arcuate dikes are arranged in spiral fashion around the main dike, suggesting that they were intruded along shear fractures similar to those described by Burbank (1941). The fused rocks surrounding the andesite dike are of three general types: 1) partly fused arkosic sand, 2) fused clay, and 3) hybrid rocks. The fused arkosic sand consists of relict detrital grains of quartz, orthoclose, and plagioclase, imbedded in colorless glass containing microlites of tridymite, cordierite, and magnetite. The relict quartz grains are corroded and embayed by glass; the orthoclase is sanidinized and partly fused; and the plagioclase is inverted to the high temperature form and is partly fused. The fused clay, which was originally a mixture of montmorillonite and hydromica, consists primarily of cordierite but also contains needle-like crystals of sillimanite (?) or mullite (?). The hybrid rocks originated in part by intermixing of fused arkosic sediments and andesitic liquid and in part by diffusion of mafic constituents through the fused sediments. They are rich in cordierite and magnetite and also contain hypersthene, augite, and plagioclase. The composition of pigeonite in the andesite indicates that the temperature of the andesite at the time of intrusion probably did not exceed 1200?C. Samples of arkosic sand were fused in the presence of water in a Morey bomb at 1050?C. Stability relations of certain minerals in the fused sand suggest that fusion may have taken place at a lower temperature, however, and the fluxing action of volatiles from the andesite are thought to have made this possible.

  19. 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.

  20. Pullout capacity of batter pile in sand

    Directory of Open Access Journals (Sweden)

    Ashraf Nazir

    2013-03-01

    Full Text Available Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Also most of retaining walls are subjected to horizontal forces and bending moments, these forces are due to earth pressure. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under axial pullout is not well established. In order to delineate the significant variables affecting the ultimate uplift shaft resistance of batter pile in dry sand, a testing program comprising 62 pullout tests was conducted. The tests are conducted on model steel pile installed in loose, medium, and dense sand to an embedded depth ratio, L/d, vary from 7.5 to 30 and with various batter angles of 0°, 10°, 20°, and 30°. Results indicate that the pullout capacity of a batter pile constructed in dense and/or medium density sand increases with the increase of batter angle attains maximum value and then decreases, the maximum value of Pα occurs at batter angle approximately equal to 20°, and it is about 21–31% more than the vertical pile capacity, while the pullout capacity for batter pile that constructed in loose sand decreases with the increase of pile inclination. The results also indicated that the circular pile is more resistant to pullout forces than the square and rectangular pile shape. The rough model piles tested is experienced 18–75% increase in capacity compared with the smooth model piles. The suggested relations for the pullout capacity of batter pile regarding the vertical pile capacity are well predicted.