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Sample records for limestone injection dry

  1. Management of solid wastes from the Limestone Injection Dry Scrubbing (LIDS) clean coal technology. Final report

    SciTech Connect

    Musiol, W.F. Jr.; Czuczwa, J.M.

    1993-03-01

    The objectives of this project were to characterize by-products from a pilot Limestone Injection Dry Scrubbing (LIDS) process and to develop processes directed toward the safe and economic use or disposal of these wastes. Because LIDS is a developing Clean Coal technology, a database of chemical and physical characteristics of the by-product was first developed. During the course of this project, it was found that the waste alone did not form high-strength products sufficient for use in construction and engineering applications. Therefore, the project was redirected to evaluate the by-product as a soil-cement and Portland cement raw material, agricultural liming agent, backfill/landfill material component, and mine reclamation/neutralizing agent. Based on these evaluations, the most viable uses for the LIDS byproduct include use in mine reclamation or as a neutralization agent. If soluble sulfites can be minimized by avoiding a dolomitic LIDS reagent, use as an agricultural liming agent has promise. Interest from an Ohio utility in the LIDS process suggests possible application of results at the demonstration or commercial stages.

  2. STEAM INJECTION INTO FRACTURED LIMESTONE AT LORING AIR FORCE BASE

    EPA Science Inventory

    A research project on steam injection for the remediation of spent chlorinated solvents from fractured limestone was recently undertaken at the former Loring AFB in Limestone, ME. Participants in the project include the Maine Department of Environmental Protection, EPA Region I,...

  3. Modified dry limestone process for control of sulfur dioxide emissions

    DOEpatents

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  4. Geophysical Monitoring of CO2Injections in Decimetric Limestone Samples

    NASA Astrophysics Data System (ADS)

    Contraires, S.; Vialle, S.; Zamora, M.; Lopez, O.; Zuddas, P.

    2007-05-01

    Within the framework of the fight against greenhouse gases emissions, one of the adopted solutions is the carbon dioxide sequestration. Injections of this gas in underground reservoir will acidify the fluid saturating the pores of the rock, which can then react with the porous matrix. The fluid-rock interactions consisting on both dissolution and precipitation reactions may modify porosity and permeability of the reservoir. Monitoring, during the injection and storage phase, will be required to detect possible leaks through the geologic strata overlaying the reservoir or modifications of its hydraulic properties. Among the available monitoring methods, geophysical techniques appear particularly adapted. In order to quantify the effect of dissolution reaction on the geophysical observables, we performed laboratory experiments on decimetric limestone samples (10 cm diameter and 30 cm length). A CO2saturated fluid percolated throughout the sample. During the experiments the core is placed into an original percolation device allowing to measure in situ and continuously different physical parameters (permeability, pH, electrical conductivity of both rock and fluid) during the solution flow through a sample. The output fluid was regularly sampled and the fluid chemical composition was analyzed. In addition, the P- and S-waves velocities and attenuations were measured along the sample (each centimeter) regularly. The results of the experiments, where a limestone reacts with CO2saturated reactive fluid (pH=4), reaching a one order of magnitude permeability increase, show that the seismic waves velocity and attenuation measurements allow us to follow the evolution of the porosity along the sample. The 3% increase of the porosity and the creation of preferential flow paths (wormholes), detected by the seismic study, are in agreement with the X-ray Computed Tomography (CT), the variations of the electrical formation factor, and the chemical analyses of the output fluid.

  5. Optimization of Trona/Limestone Injection for SO2 Control in Coal-Fired Boilers

    SciTech Connect

    2005-09-01

    Mobotec USA develops and markets air pollution control systems for utility boilers and other combustion systems. They have a particular interest in technologies that can reduce NOx, SOx, and mercury emissions from coal-fired boilers, and have been investigating the injection of sorbents such as limestone and trona into a boiler to reduce SOx and Hg emissions. WRI proposed to use the Combustion Test Facility (CTF) to enable Mobotec to conduct a thorough evaluation of limestone and trona injection for SO{sub 2} control. The overall goal of the project was to characterize the SO{sub 2} reductions resulting from the injection of limestone and trona into the CTF when fired with a high-sulfur eastern bituminous coal used in one of Mobotec's Midwest installations. Results revealed that when limestone was injected at Ca:S molar ratios of 1.5 to 3.0, the resulting SO{sub 2} reductions were 35-55%. It is believed that further reductions can be attained with improved mixing of the sorbent with the combustion gases. When limestone was added to the coal, at Ca:S molar ratios of 0.5 to 1.5, the SO{sub 2} reductions were 13-21%. The lower reductions were attributed to dead-burning of the sorbent in the high temperature flame zone. In cases where limestone was both injected into the furnace and added to the coal, the total SO{sub 2} reductions for a given Ca:S molar ratio were similar to the reductions for furnace injection only. The injection of trona into the mid-furnace zone, for Na:S molar ratios of 1.4 to 2.4, resulted in SO{sub 2} reductions of 29-43%. Limestone injection did not produce any slag deposits on an ash deposition probe while trona injection resulted in noticeable slag deposition.

  6. Full-scale results for TAM limestone injection

    SciTech Connect

    Baer, S.

    1996-12-31

    Information is outlined on the use of thermally active marble (TAM) sorbents in boilers. Data are presented on: the comparison of TAM to limestone; NOVACON process development history; CFB test history; CFB pilot scale test; full-scale CFB trial; August, 1996 CFB demonstration; Foster Wheeler Mount Carmel sorbent feed rate comparison and Ca:S comparison; unburned carbon is ash; and advantages and savings in CFB boilers.

  7. Core size effect on the dry and saturated ultrasonic pulse velocity of limestone samples.

    PubMed

    Ercikdi, Bayram; Karaman, Kadir; Cihangir, Ferdi; Yılmaz, Tekin; Aliyazıcıoğlu, Şener; Kesimal, Ayhan

    2016-12-01

    This study presents the effect of core length on the saturated (UPVsat) and dry (UPVdry) P-wave velocities of four different biomicritic limestone samples, namely light grey (BL-LG), dark grey (BL-DG), reddish (BL-R) and yellow (BL-Y), using core samples having different lengths (25-125mm) at a constant diameter (54.7mm). The saturated P-wave velocity (UPVsat) of all core samples generally decreased with increasing the sample length. However, the dry P-wave velocity (UPVdry) of samples obtained from BL-LG and BL-Y limestones increased with increasing the sample length. In contrast to the literature, the dry P-wave velocity (UPVdry) values of core samples having a length of 75, 100 and 125mm were consistently higher (2.8-46.2%) than those of saturated (UPVsat). Chemical and mineralogical analyses have shown that the P wave velocity is very sensitive to the calcite and clay minerals potentially leading to the weakening/disintegration of rock samples in the presence of water. Severe fluctuations in UPV values were observed to occur between 25 and 75mm sample lengths, thereafter, a trend of stabilization was observed. The maximum variation of UPV values between the sample length of 75mm and 125mm was only 7.3%. Therefore, the threshold core sample length was interpreted as 75mm for UPV measurement in biomicritic limestone samples used in this study.

  8. Core size effect on the dry and saturated ultrasonic pulse velocity of limestone samples.

    PubMed

    Ercikdi, Bayram; Karaman, Kadir; Cihangir, Ferdi; Yılmaz, Tekin; Aliyazıcıoğlu, Şener; Kesimal, Ayhan

    2016-12-01

    This study presents the effect of core length on the saturated (UPVsat) and dry (UPVdry) P-wave velocities of four different biomicritic limestone samples, namely light grey (BL-LG), dark grey (BL-DG), reddish (BL-R) and yellow (BL-Y), using core samples having different lengths (25-125mm) at a constant diameter (54.7mm). The saturated P-wave velocity (UPVsat) of all core samples generally decreased with increasing the sample length. However, the dry P-wave velocity (UPVdry) of samples obtained from BL-LG and BL-Y limestones increased with increasing the sample length. In contrast to the literature, the dry P-wave velocity (UPVdry) values of core samples having a length of 75, 100 and 125mm were consistently higher (2.8-46.2%) than those of saturated (UPVsat). Chemical and mineralogical analyses have shown that the P wave velocity is very sensitive to the calcite and clay minerals potentially leading to the weakening/disintegration of rock samples in the presence of water. Severe fluctuations in UPV values were observed to occur between 25 and 75mm sample lengths, thereafter, a trend of stabilization was observed. The maximum variation of UPV values between the sample length of 75mm and 125mm was only 7.3%. Therefore, the threshold core sample length was interpreted as 75mm for UPV measurement in biomicritic limestone samples used in this study. PMID:27529138

  9. Use of borehole radar tomography to monitor steam injection in fractured limestone

    USGS Publications Warehouse

    Gregoire, C.; Joesten, P.K.

    2006-01-01

    Borehole radar tomography was used as part of a pilot study to monitor steam-enhanced remediation of a fractured limestone contaminated with volatile organic compounds at the former Loring Air Force Base, Maine, USA. Radar tomography data were collected using 100-MHz electric-dipole antennae before and during steam injection to evaluate whether cross-hole radar methods could detect changes in medium properties resulting from the steam injection. Cross-hole levelrun profiles, in which transmitting and receiving antennae are positioned at a common depth, were made before and after the collection of each full tomography data set to check the stability of the radar instruments. Before tomographic inversion, the levelrun profiles were used to calibrate the radar tomography data to compensate for changes in traveltime and antenna power caused by instrument drift. Observed changes in cross-hole radar traveltime and attenuation before and during steam injection were small. Slowness- and attenuation-difference tomograms indicate small increases in radar slowness and attenuation at depths greater than about 22 m below the surface, consistent with increases in water temperature observed in the boreholes used for the tomography. Based on theoretical modelling results, increases in slowness and attenuation are interpreted as delineating zones where steam injection heating increased the electrical conductivity of the limestone matrix and fluid. The results of this study show the potential of cross-hole radar tomography methods to monitor the effects of steam-induced heating in fractured rock environments. ?? 2006 European Association of Geoscientists & Engineers.

  10. Laboratory study of SO2 dry deposition on limestone and marble: Effects of humidity and surface variables

    USGS Publications Warehouse

    Spiker, E. C.; Hosker, R.P.; Weintraub, V.C.; Sherwood, S.I.

    1995-01-01

    The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3, nitrogen oxides) can be held constant. An airfoil sample holder holds up to eight stone samples (3.8 cm in diameter and 1 cm thick) in nearly identical exposure conditions. SO2 deposition on limestone was found to increase exponentially with increasing relative humidity (RH). Marble behaves similarly, but with a much lower deposition rate. Trends indicate there is little deposition below 20% RH on clean limestone and below 60% RH on clean marble. This large difference is due to the limestone's greater porosity, surface roughness, and effective surface area. These results indicate surface variables generally limit SO2 deposition below about 70% RH on limestone and below at least 95% RH on marble. Aerodynamic variables generally limit deposition at higher relative humidity or when the surface is wet.The dry deposition of gaseous air pollutants on stone and other materials is influenced by atmospheric processes and the chemical characteristics of the deposited gas species and of the specific receptor material. Previous studies have shown that relative humidity, surface moisture, and acid buffering capability of the receptor surface are very important factors. To better quantify this behavior, a special recirculating wind tunnel/environmental chamber was constructed, in which wind speed, turbulence, air temperature, relative humidity, and concentrations of several pollutants (SO2, O3

  11. Determining the distribution of hydraulic conductivity in a fractured limestone aquifer by simultaneous injection and geophysical logging

    USGS Publications Warehouse

    Morin, R.H.; Hess, A.E.; Paillet, Frederick L.

    1988-01-01

    A field technique for assessing the vertical distribution of hydraulic conductivity in an aquifer was applied to a fractured carbonate formation in southeastern Nevada. The technique combines the simultaneous use of fluid injection and geophysical logging to measure in situ vertical distributions of fluid velocity and hydraulic head down the borehole; these data subsequently are analyzed to arrive at quantitative estimates of hydraulic conductivity across discrete intervals in the aquifer. The results of this analysis identified the contact margin between the Anchor and Dawn Members of the Monte Cristo Limestone as being the dominant transmissive unit. -from Authors

  12. Steam injection pilot study in a contaminated fractured limestone (Maine, USA): Modeling and analysis of borehole radar reflection data

    USGS Publications Warehouse

    Gregoire, C.; Lane, J.W.; Joesten, P.K.

    2005-01-01

    Steam-enhanced remediation (SER) has been successfully used to remove DNAPL and LNAPL contaminants in porous media. Between August and November 2002, SER was tested in fractured limestone at the former Loring Air Force Base, in Maine, USA. During the SER investigation, the U.S. Geological Survey conducted a series of borehole radar surveys to evaluate the effectiveness of radar methods for monitoring the movement of steam and heat through the fractured limestone. The data were collected before steam injection, 10 days after the beginning of injection, and at the end of injection. In this paper, reflection-mode borehole radar data from wells JBW-7816 and JBW-7817A are presented and discussed. Theoretical modeling was performed to predict the variation of fracture reflectivity owed to heating, to show displacement of water and to assess the effect of SER at the site. Analysis of the radar profile data indicates some variations resulting from heating (increase of continuity of reflectors, attenuation of deeper reflections) but no substantial variation of traveltimes. Spectral content analysis of several individual reflections surrounding the boreholes was used to investigate the replacement of water by steam in the fractures. Observed decrease in radar reflectivity was too small to be explained by a replacement of water by steam, except for two high-amplitude reflectors, which disappeared near the end of the injection; moreover, no change of polarity, consistent with steam replacing water, was observed. The decrease of amplitude was greater for reflectors near well JBW-7817A and is explained by a greater heating around this well.

  13. Retrofit costs for lime/limestone FGD and lime spray drying at coal-fired utility boilers

    SciTech Connect

    Emmel, T.E.; Jones, J.W.

    1990-01-01

    The paper gives results of a research program the objective of which was to significantly improve engineering cost estimates currently being used to evaluate the economic effects of applying SO2 controls to existing coal-fired utility boilers. The costs of retrofitting conventional lime/limestone wet flue gas desulfurization (L/LS FGD) and lime spray drying (LSD) FGD at 100-200 coal-fired power plants are being estimated under this program. The retrofit capital cost estimating procedures used for L/LS FGD and LSD FGD make two cost adjustments to current procedures used to estimate FGD costs: cost adders (for items not normally included in FGD system costs; e.g., demolition and relocation of existing facilities) and cost multipliers (to adjust capital costs for site access, congestion, and underground obstructions).

  14. Proof of concept testing of an integrated dry injection system for SO{sub 2}/NO{sub x} control. Final report

    SciTech Connect

    Helfritch, D.J.; Bortz, S.J.; Beittel, R.

    1994-03-01

    The integrated Dry Injection Process (IDIP) consists of combustion modification using low NO{sub x} burners to reduce NO{sub x} emissions, dry injection of hydrated line at economizer temperatures for primary capture of SO{sub 2}, dry injection of a commercial grade sodium bicarbonate at the air heater exit for additional SO{sub 2} and NO{sub x} removal, and humidification for precipitator conditioning. IDIP offers the potential for simultaneously achieving 90% SO{sub 2} removal, and 65% NO{sub x} removal from a high sulfur flue gas. The process is well suited for new or retrofit applications since it can be incorporated within existing economizer and downstream ductwork. Subscale tests were performed in order to identify the best calcium and sodium sorbents. These tests involved the injection of calcium hydroxide and sodium sorbents at various points of the flue gas system downstream of a 0.25 MM BTU/hr. coal fired combustor, and the gas residence times, cooling rates and temperatures were comparable to those found for full-scale utility boilers. These tests verified that a high surface area hydrated lime provides maximum sorbent utilization and identified an alcohol-water hydrated lime as yielding the highest surface area and the best SO{sub 2} removal capability. The tests also identified sodium bicarbonate to be somewhat more effective than sodium sesquicarbonate for SO{sub 2} removal. The proof of concept demonstration was conducted on the large combustor at the Riley Stoker Research Facility in Worcester, MA. When economically compared to conventional limestone slurry scrubbing on a 300 MW plant, the dry injection process shows lower capital cost but higher operating cost. Hydrated lime injection can be less costly than limestone scrubbing when two or more of the following conditions exist: plant is small (less than 100MW); yearly operating hours are small (less than 3000); and the remaining plant lifetime is small (less than 10 years).

  15. Limestone Caverns

    ERIC Educational Resources Information Center

    Powell, Richard L.

    1970-01-01

    Describes the origin of limestone caverns, using Mammoth Cave as an example, with particular reference to the importance of groundwater information of caverns, the present condition of groundwater, and how caverns develop within fluctuating groundwater zones. (BR)

  16. Limestone geomorphology

    SciTech Connect

    Trudgill, S.

    1985-01-01

    This book focuses on recent work on geomorphological processes and relates them to established theories of landform development. Special attention is paid to soil processes, marine geomorphology, chemical processes and future work on process-form relationships in the context of dated sequences of cave deposits. There are discussions of limestone landforms and other carbonate rocks, caves, hydrological networks, features of karst, morphometry, and coastal landforms and solution chemistry of limestones.

  17. Lidocaine injection versus dry needling to myofascial trigger point. The importance of the local twitch response.

    PubMed

    Hong, C Z

    1994-01-01

    This study was designed to investigate the effects of injection with a local anesthetic agent or dry needling into a myofascial trigger point (TrP) of the upper trapezius muscle in 58 patients. Trigger point injections with 0.5% lidocaine were given to 26 patients (Group I), and dry needling was performed on TrPs in 15 patients (Group II). Local twitch responses (LTRs) were elicited during multiple needle insertions in both Groups I and II. In another 17 patients, no LTR was elicited during TrP injection with lidocaine (9 patients, group Ia) or dry needling (8 patients, group IIa). Improvement was assessed by measuring the subjective pain intensity, the pain threshold of the TrP and the range of motion of the cervical spine. Significant improvement occurred immediately after injection into the patients in both group I and group II. In Groups Ia and Ib, there was little change in pain, tenderness or tightness after injection. Within 2-8 h after injection or dry needling, soreness (different from patients' original myofascial pain) developed in 42% of the patients in group I and in 100% of the patients in group II. Patients treated with dry needling had postinjection soreness of significantly greater intensity and longer duration than those treated with lidocaine injection. The author concludes that it is essential to elicit LTRs during injection to obtain an immediately desirable effect. TrP injection with 0.5% lidocaine is recommended, because it reduces the intensity and duration of postinjection soreness compared with that produced by dry needling.

  18. Develop to Term Rat Oocytes Injected with Heat-Dried Sperm Heads

    PubMed Central

    Lee, Kyung-Bon; Park, Ki-Eun; Kwon, In-Kiu; Tripurani, Swamy K.; Kim, Keun Jung; Lee, Ji Hye; Niwa, Koji; Kim, Min Kyu

    2013-01-01

    This study investigated the development of rat oocytes in vitro and in vivo following intracytoplasmic injection of heads from spermatozoa heat-dried at 50°C for 8 h and stored at 4°C in different gas phases. Sperm membrane and chromosome are damaged by the process of heat-drying. Oocyte activation and cleavage of oocytes were worse in oocytes injected with spermatozoa heat-dried and stored for 1 week than unheated, fresh spermatozoa, but in heat-dried spermatozoa, there were no differences in these abilities of oocytes between the samples stored in nitrogen gas and in air. The oocytes injected with heat-dried spermatozoa stored for 1 week could develop to the morula and blastocyst stages without difference between the samples stored in nitrogen gas and in air after artificial stimulation. Cleavage of oocytes and development of cleaved embryos were higher when heat-dried spermatozoa were stored for 3 and 6 months in nitrogen gas than in air. However, the ability of injected oocytes to develop to the morula and blastocyst stages was not inhibited even when heat-dried spermatozoa stored in both atmosphere conditions for as long as 6 months were used. When 2-cell embryos derived from oocytes injected with heads from spermatozoa heat-dried and stored for 1 week and 1 month were transferred, each 1 of 4 recipients was conceived, and the conceived recipients delivered 1 live young each. These results demonstrate that rat oocytes can be fertilized with heat-dried spermatozoa and that the fertilized oocytes can develop to term. PMID:24223784

  19. LIFAC sorbent injection desulfurization demonstration project

    SciTech Connect

    Not Available

    1991-01-01

    LIFAC combines upper-furnace limestone injection followed by post-furnace humidification in an activation reactor located between the air preheater and the ESP. The process produces a dry and stable waste product that is partially removed from the bottom of the activation reactor and partially removed at the ESP.

  20. EVALUATION OF FGD DRY INJECTION SORBENTS AND ADDITIVES - VOLUME 2 - PILOT PLANT EVALUATION OF HIGH REACTIVITY SORBENTS

    EPA Science Inventory

    The report describes a mini-pilot test program to investigate potential new sorbents and processes for dry SO2 removal. Initial tests showed that the 85 cu m/h pilot plant could be used successfully to evaluate both spray dryer and dry injection processes using traditional calciu...

  1. Pilot scale-SO{sub 2} control by dry sodium bicarbonate injection and an electrostatic precipitator

    SciTech Connect

    Pliat, M.J.; Wilder, J.M.

    2007-10-15

    A 500 actual cubic feet gas per minute (acfm) pilot-scale SO{sub 2} control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400{sup o}F (204.5{sup o}C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO{sub 2}. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO{sub 2} concentrations were measured upstream of the reagent injection, 25-ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO{sub 2} collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in-duct SO{sub 2} removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide-sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature.

  2. Simulations of dry-out and halite precipitation due to CO2 injection

    NASA Astrophysics Data System (ADS)

    Hurter, S.; Labregere, D.; Berge, J.

    2007-12-01

    Although H2O is not very soluble in supercritical CO2, a continuous stream of CO2 injected into a formation, will cause a region around the injection well to dry out. As the water of the formation brine is continuously evaporated into the CO2, the irreducible water saturation may attain practically zero. Enhanced injectivity is the result of this process in a low salinity brine environment. In formations saturated with highly saline brine (e.g. Northern German Basin) the outcome is opposite: injectivity is impaired. In this case, the brine becomes supersaturated as continuously H2O evaporates into the CO2 phase and salt (halite) precipitates in the pores. The porosity and permeability diminish, which can lead to the loss of a well. We present simulations of these processes as an example of pre-injection study for a CO2 injection and storage site. The simulation tool consists of a commercial compositional code used extensively in the oil and gas industry to simulate the flow of multiple phases (oil, water, gas) in porous or fractured media. The mutual solubility of CO2 and H2O with a correction for salinity is implemented as described in Spycher and Pruess (2005). The brine salinity is adjusted accordingly until the saturation threshold is reached and halite is precipitated. The distribution of precipitation in the reservoir depends not only of the relationship between permeability change as a function of porosity change, but also on the relative permeability curves for the CO2-brine system. Therefore it is essential to establish relative permeability curves in the laboratory, as well as to obtain a relationship between porosity change and permeability variation with precipitation by laboratory experiments on cores to obtain meaningful results from numerical simulations. References Spycher N. and Pruess, K. (2005), CO2-H2O mixtures in the geological sequestration of CO2, II Partitioning in chloride brines at 12-100° and up to 600 bar, Geochim. Cosmochim. Acta 69

  3. INVESTIGATION AND DEMONSTRATION OF DRY CARBON-BASED SORBENT INJECTION FOR MERCURY CONTROL

    SciTech Connect

    Terry Hunt; Mark Fox; Lillian Stan; Sheila Haythornthwaite; Justin Smith; Jason Ruhl

    1998-10-01

    This quarterly report describes the activities that have taken place during the first full quarter of the Phase II project ''Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control''. Modifications were completed and sampling began at the 600 acfm pilot-scale particulate control module (PCM) located at the Comanche Station in Pueblo, CO. The PCM was configured as an electrostatic precipitator for these tests. A Perkin-Elmer flue gas mercury analyzer was installed on-site and operated. Initial test results using both manual sampling methodology and the mercury analyzer are presented herein. Preparations were made during this period for full-scale mercury testing of several PSCo units. A site visit was made to Arapahoe and Cherokee Generating Stations to determine sample locations and to develop a test plan.

  4. Integrated dry NO{sub x}/SO{sub 2} emissions control system calcium-based dry sorbent injection. Test report, April 30--November 2, 1993

    SciTech Connect

    Shiomoto, G.H.; Smith, R.A.; Muzio, L.J.; Hunt, T.

    1994-12-01

    The DOE sponsored Integrated Dry NO{sub x}SO{sub 2} Emissions Control System program, which is a Clean Coal Technology III demonstration, is being conducted by Public Service Company of Colorado. The test site is Arapahoe Generating Station Unit 4, which is a 100 MWe, down-fired utility boiler burning a low sulfur Western coal. The project goal is to demonstrate up to 70 percent reductions in NO{sub x} and SO{sub 2} emissions through the integration of: (1) down-fired low-NO{sub x} burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NO{sub x} removal; and (3) dry sorbent injection and duct humidification for SO{sub 2} removal. The effectiveness of the integrated system on a high-sulfur coal will also be investigated. This report documents the fifth phase of the test program, where the performance of the dry sorbent injection of calcium was evaluated as an SO{sub 2} removal technique. Dry sorbent injection with humidification was performed downstream of the air heater (in-duct). Calcium injection before the economizer was also investigated. The in-duct calcium sorbent and humidification retrofit resulted in SO{sub 2} reductions of 28 to 40 percent, with a Ca/S of 2, and a 25 to 30{degrees}F approach to adiabatic saturation temperature. The results of the economizer calcium injection tests were disappointing with less than 10 percent SO{sub 2} removal at a Ca/S of 2. Poor sorbent distribution due to limited access into the injection cavity was partially responsible for the low overall removals. However, even in areas of high sorbent concentration (local Ca/S ratios of approximately 6), SO{sub 2} removals were limited to 30 percent. It is suspected that other factors (sorbent properties and limited residence times) also contributed to the poor performance.

  5. Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control

    SciTech Connect

    Jim Butz; Terry Hunt

    2005-11-01

    Public Service Company of Colorado and ADA Technologies, Inc. have performed a study of the injection of activated carbon for the removal of vapor-phase mercury from coal-fired flue gas streams. The project was completed under contract to the US Department of Energy's National Energy Technology Laboratory, with contributions from EPRI and Public Service Company. The prime contractor for the project was Public Service Company, with ADA Technologies as the major subcontractor providing technical support to all aspects of the project. The research and development effort was conducted in two phases. In Phase I a pilot facility was fabricated and tests were performed using dry carbon-based sorbent injection for mercury control on a coal-fired flue gas slipstream extracted from an operating power plant. Phase II was designed to move carbon injection technology towards commercial application on coal-fired power plants by addressing key reliability and operability concerns. Phase II field work included further development work with the Phase I pilot and mercury measurements on several of PSCo's coal-fired generating units. In addition, tests were run on collected sorbent plus fly ash to evaluate the impact of the activated carbon sorbent on the disposal of fly ash. An economic analysis was performed where pilot plant test data was used to develop a model to predict estimated costs of mercury removal from plants burning western coals. Testing in the pilot plant was undertaken to quantify the effects of plant configuration, flue gas temperature, and activated carbon injection rate on mercury removal. All three variables were found to significantly impact the mercury removal efficiency in the pilot. The trends were clear: mercury removal rates increased with decreasing flue gas temperature and with increasing carbon injection rates. Mercury removal was much more efficient with reverse-gas and pulse-jet baghouse configurations than with an ESP as the particulate control device

  6. Determination of dry carbon-based sorbent injection for mercury control in utility ESP and baghouses

    SciTech Connect

    Broderick, T.; Haythornthwaite, S.; Bell, W.; Selegue, T.; Perry, M.

    1998-12-31

    Domestic coal-fired power plants emit approximately 40 to 80 metric tons of mercury to the atmosphere annually. The mercury concentration in utility flue gas is in the dilute range of 0.1 to 1 parts per billion. The EPA is assessing whether such low concentrations of mercury emissions from coal-fired utilities pose any significant health risk and whether mercury regulations would be necessary or appropriate. In anticipation of possible mercury control regulations, ADA Technologies (ADA) and TDA Research, Inc (TDA) were funded by the Department of Energy (DOE) to evaluate carbon-based sorbents for mercury control at utility coal-fired power plants. Past investigations of the use of dry carbon-based sorbent injection for mercury control on pilot-scale utility flue gas applications have shown that these sorbents are capable of removing gas-phase mercury. ADA Technologies field-tested the mercury removal capability of several carbon-based sorbents manufactured by TDA. The test facility was a DOE-owned test facility built and operated by ADA at the Public Service Company of Colorado`s Comanche Station in Pueblo, Colorado. The pilot-scale test fixture is a 600-acfm particulate control module that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse. It extracts a slipstream of flue gas from a coal-fired utility boiler. Sorbent is injected into the flue gas slipstream upstream of the particulate control module and is removed by the module. ADA evaluated the mercury capture efficiency of the sorbents over a range of flue gas temperatures and injection rates. In addition, the effect of flyash on mercury capture was also investigated. The test facility is configured to take flue gas from either upstream or downstream of Comanche Station`s full-scale reverse-gas baghouse, allowing tests to be conducted with normal-ash or low-ash flue gas.

  7. High-pressure hand injection injuries caused by dry cleaning solvents: case reports, review of the literature, and treatment guidelines.

    PubMed

    Gutowski, Karol A; Chu, Jason; Choi, Mihye; Friedman, David W

    2003-01-01

    A previously unreported subset of high-pressure injection injuries, namely those involving solvents used in the garment dry cleaning industry, is presented. Dry cleaning solutions contain isoparaffinic hydrocarbons, methoxypropanol, and dichlorofluoroethane. Although these solvents have limited potential for systemic toxicity, severe local toxicity causing tissue necrosis often results in loss of the injured digit. Proper treatment includes prompt surgical exploration, careful débridement and irrigation, intravenous antibiotics, and in selected cases, high-dose systemic corticosteroids. PMID:12496578

  8. Formation dry-out from CO2 injection into saline aquifers: Part 1, Effects of solids precipitation and their mitigation

    SciTech Connect

    Pruess, Karsten; Muller, Nadja

    2009-02-01

    Injection of CO{sub 2} into saline aquifers may cause formation dry-out and precipitation of salt near the injection well, which may reduce formation porosity, permeability, and injectivity. This paper uses numerical simulation to explore the role of different processes and parameters in the salt precipitation process and to examine injection strategies that could mitigate the effects. The main physical mechanisms affecting the dry-out and salt precipitation process include (1) displacement of brine away from the injection well by injected CO{sub 2}, (2) dissolution (evaporation) of brine into the flowing CO{sub 2} stream, (3) upflow of CO{sub 2} due to gravity effects (buoyancy), (4) backflow of brine toward the injection point due to capillary pressure gradients that oppose the pressure gradient in the CO{sub 2}-rich ('gas') phase, and (5) molecular diffusion of dissolved salt. The different mechanisms operate on a range of spatial scales. CO{sub 2} injection at constant rate into a homogeneous reservoir with uniform initial conditions is simulated in 1-D radial geometry, to resolve multiscale processes by taking advantage of the similarity property, i.e., the evolution of system conditions as a function of radial distance R and time t depends only on the similarity variable R{sup 2}/t. Simulations in 2-D vertical cross sections are used to examine the role of gravity effects. We find that counterflow of CO{sub 2} and brine can greatly increase aqueous phase salinity and can promote substantial salt precipitation even in formations with low dissolved solids. Salt precipitation can accentuate effects of gravity override. We find that injecting a slug of fresh water prior to commencement of CO{sub 2} injection can reduce salt precipitation and permeability loss near the injection well.

  9. Demonstration of dry carbon-based sorbent injection for mercury control in utility ESPs and baghouses

    SciTech Connect

    Sjostrom, S.; Smith, J.; Hunt, T.; Chang, R.; Brown, T.D.

    1997-12-31

    Domestic coal-fired power plants emit approximately 40 to 80 metric tons of mercury to the atmosphere annually, approximately 30% of all mercury emissions from human activities. However, the mercury concentration in utility flue gas is in the extremely dilute range of 0.1 to 1 part per billion. The EPA is assessing whether such low concentrations of mercury emissions from coal-fired utilities pose any significant health risk and whether mercury regulations would be necessary or appropriate. In anticipation of possible mercury control regulations, DOE has funded Public Service Company of Colorado (PSCo) to evaluate carbon-based sorbents for mercury control at utility coal-fired power plants. Initial investigations of the use of dry carbon-based sorbent injection for mercury control on utility applications have shown that carbon-based sorbents are capable of removing gaseous phase mercury. Because of the difficulty in capturing and measuring mercury, however, it is important to evaluate these technologies extensively on actual utility flue gas. Testing is currently underway on a slipstream of flue gas from PSCo`s Comanche Station in Pueblo, Colorado. The test fixture is a 600 acfm particulate control module that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse. Sorbent is injected into the flue gas slipstream prior to the particulate control module, and is removed by the module. Flue gas temperature and sorbent residence time can be changed to evaluate a range of plant operating conditions. In addition, the effect of fly ash on mercury capture can be evaluated because the flue gas slipstream can be taken from either upstream or downstream of Comanche Station`s full-scale reverse-gas baghouse. This paper describes the results of initial pilot testing in both an electrostatic precipitator and a pulse-jet baghouse.

  10. Effectiveness of dry needling and injections of myofascial trigger points associated with plantar heel pain: a systematic review

    PubMed Central

    2010-01-01

    Background Plantar heel pain (plantar fasciitis) is one of the most common musculoskeletal pathologies of the foot. Plantar heel pain can be managed with dry needling and/or injection of myofascial trigger points (MTrPs) however the evidence for its effectiveness is uncertain. Therefore, we aimed to systematically review the current evidence for the effectiveness of dry needling and/or injections of MTrPs associated with plantar heel pain. Methods We searched specific electronic databases (MEDLINE, EMBASE, AMED, CINAHL, SPORTDiscus and AMI) in April 2010 to identify randomised and non-randomised trials. We included trials where participants diagnosed with plantar heel pain were treated with dry needling and/or injections (local anaesthetics, steroids, Botulinum toxin A and saline) alone or in combination with acupuncture. Outcome measures that focussed on pain and function were extracted from the data. Trials were assessed for quality using the Quality Index tool. Results Three quasi-experimental trials matched the inclusion criteria: two trials found a reduction in pain for the use of trigger point dry needling when combined with acupuncture and the third found a reduction in pain using 1% lidocaine injections when combined with physical therapy. However, the methodological quality of the three trials was poor, with Quality Index scores ranging form 7 to 12 out of a possible score of 27. A meta-analysis was not conducted because substantial heterogeneity was present between trials. Conclusions There is limited evidence for the effectiveness of dry needling and/or injections of MTrPs associated with plantar heel pain. However, the poor quality and heterogeneous nature of the included studies precludes definitive conclusions being made. Importantly, this review highlights the need for future trials to use rigorous randomised controlled methodology with measures such as blinding to reduce bias. We also recommend that such trials adhere to the Standards for Reporting

  11. Acid drainage response to surface limestone layers

    SciTech Connect

    Geidel, G.; Caruccio, F.T.

    1982-12-01

    A 150 acre drainage basin in an unreclaimed coal strip mine in east-central Ohio was studied and extensively monitored to determine the effect of a surface application of limestone on the ground water quality. Prior to the limestone treatment the ground and surface water of the basin was acidic due to pyrite oxidation in the spoil. In order to assess the effect of the limestone application the basin was divided into seven sub-basins, five of which were treated and two which served as controls. The seeps from the treated sub-basins with low acid concentrations became alkaline due to neutralization but after a long dry period, they returned to their acid condition. The moderately and highly acidic seeps showed a decline in the acid concentrations which could be attributed to a combination of neutralization and a decrease in the rate of pyrite oxidation. The results of this field study and simultaneous laboratory experiments showed that under natural conditions, with no limestone application, the acidity generated by pyrite oxidation in a backfill decreased. A surface application of limestone slightly enhanced the decrease in acidity by both neutralization and decreasing the rate of pyrite oxidation. However, the limestone application did not provide sufficient alkalinity to produce either neutral or alkaline discharges from the abandoned coal strip mine site.

  12. BASIC computer program calculates FGD limestone use

    SciTech Connect

    Buecker, B. )

    1992-09-01

    This paper reports that engineers can use available data with this computer program to predict how much limestone the FGD system will be used. Up to now, utilities with limestone FGD systems in their power plants have found it economical to scrub only the amount of gas needed to meet SO[sub 2] emissions limits. However, the Clean Air Act Amendments of 1990 and the rules allowing credits for reduced SO[sub 2] discharges make overscrubbing more attractive. The BASIC computer program in Figure 1 illustrates a method to calculate projected limestone use based on data routinely determined by utility engineers. The program, as it is written, has been used successfully to estimate limestone consumption on a 200-MW, coal-fired boiler with a wet-limestone, forced-air oxidized FGD system. This system meets the required SO[sub 2] emissions limit of 1.2 lb/MBtu. Two factors have made the program successful. First, gas flow to the scrubber is controlled with the help of a bypass system, whereby some of the untreated flue gas is injected directly into the stack. Thus, SO[sub 2] emissions are controlled by varying the amount of gas sent through the scrubber and not by changing process chemistry. Second, the utility has a single supplier of coal and a single supplier of high-purity limestone.

  13. Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control

    SciTech Connect

    Jason Ruhl; Justin Smith; Sharon Sjostrom; Sheila Haythorthwaite; Terry Hunt

    1997-08-01

    The U.S. Department of Energy (DOE) issued Public Service Company of Colorado (PSCO) a cost sharing contract to evaluate carbon-based sorbents for mercury control on a 600 acfm laboratory-scale particulate control module (PCM). The PCM can be configured as simulate an electrostatic precipitator, a pulse-jet fabric filter, or a reverse-gas fabric filter and is installed on an operating coal-fired power plant. Three different dry carbon-based sorbents were tested this quarter to determine their mercury removal capability in the different configurations. The project is currently in the seventh quarter of an eight-quarter Phase I project. Testing in all configurations is nearly complete. Original plans included the use of an on-line mercury analyzer to collect test data. However, due to very low baseline mercury concentration, on-line measurement did not provide accurate data. The project used a modified MESA method grab sample technique to determine inlet and outlet mercury concentrations. A major concern during sorbent evaluations was the natural ability of the flyash at the test site to remove mercury. This often made determination of sorbent only mercury removal difficult. The PCM was configured as a reverse-gas baghouse and brought online with "clean" flue gas on March 10* at an A/C of 2.0 ft/min. The dustcake forms the filtering media in a reverse gas baghouse. In the absence of flyash, the bags were precoated with a commercially available alumina silicate material to form an inert dustcake. Some baseline tests were completed with clean gas for comparison to clean gas pulse jet tests. The PCM was reconfigured as a TOXECON unit in April 1997 with testing completed in May 1997. TOXECON, an EPIU patented technology, is a pulse-jet baghouse operating at a high A/C ratio downstream of a primary particulate colIector with sorbent injection upstream of the baghouse for air toxics removal. Mercury removals of O to 97o/0 were obtained depending on test conditions.

  14. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    DOEpatents

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  15. LIFAC sorbent injection desulfurization demonstration project. Quarterly report No. 3, April--June 1991

    SciTech Connect

    Not Available

    1991-12-31

    LIFAC combines upper-furnace limestone injection followed by post-furnace humidification in an activation reactor located between the air preheater and the ESP. The process produces a dry and stable waste product that is partially removed from the bottom of the activation reactor and partially removed at the ESP.

  16. Recovery and recycling of limestone in LEC flue gas desulfurization

    SciTech Connect

    Gardner, N.C.; Adler, R.J.; Lin, Y.C.; Unger, M.E.; Lux, K.W. )

    1992-03-01

    Prudich et al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases. Sulfates and sulfites deposit on the surfaces of the particles, limiting their utilization to about 20%. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economic costs derive from small equipment, simplicity, and low sorbent cost. Our research concentrates on selecting and testing on a laboratory scale suitable candidate dry and wet grinding methods for recovering limestone in LEC flue from desulfurization. A wet grinding method based on the impeller fluidizer, a new type of slurry processor, receives special attention. The impeller fluidizer is a dosed cylindrical vessel with an impeller at one end. It combines the operations of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry.

  17. Technical and economic evaluation of dry sorbent injection for SO/sub 2/ control using sodium compounds

    SciTech Connect

    Green, G.P.; Carr, R.C.; Hooper, R.G.

    1984-01-01

    Public Service Company of Colorado (PSCC) has committed to all-dry sorbent injection for SO/sub 2/ control on a new 500 MW coal-fired boiler, Pawnee Unit 2. Although no commitment has been made for construction of Pawnee 2, for engineering and planning purposes it is scheduled to begin service in 1990 burning western, low-sulfur, subbituminous coal. PSCC is currently the only electric utility to announce firm plans to employ this control technology. The purpose of this paper is to present the reasons for this commitment. It is hoped that this discussion will be of benefit to other electric utilities considering SO/sub 2/ control options.

  18. [Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

    PubMed

    Huang, Dao-sheng; Shi, Wei; Han, Lei; Sun, Ke; Chen, Guang-bo; Wu Jian-xiong; Xu, Gui-hong; Bi, Yu-an; Wang, Zhen-zhong; Xiao, Wei

    2015-06-01

    To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

  19. Formation dry-out from CO2 injection into saline acquifers: Part 2, Analytical model for salt precipitation

    SciTech Connect

    Pruess, Karsten

    2009-02-01

    From a mass balance for water dissolved into the flowing CO{sub 2} stream, and a consideration of saturation profiles from the Buckley-Leverett (1942) fractional flow theory, we derive an equation that directly relates gas saturation S{sub g,d} at the dry-out front to temperature, pressure and salinity dependence of fluid properties. The equation is easily solved by iteration or interpolation. From gas saturation at the front we derive the average gas saturation in the dry-out region, from which we obtain the 'solid saturation' S{sub S}, i.e., the fraction of pore space filled with solid precipitate. Values of S{sub S} derived from this theory show excellent agreement with numerical simulations presented in the preceding companion paper ('Part 1'). Thus, from relative permeabilities and fluid properties at in situ conditions prior to CO{sub 2} injection, it is possible to directly make an accurate estimate of solids precipitation, without having to perform a numerical simulation of the injection process.

  20. Crystalline marble beats limestone for fluegas desulfurization

    SciTech Connect

    1996-05-01

    NovaCon Energy Systems, Inc. (Bedford, NY) has developed an alternative to conventional limestone sorbents. The new process uses a class of marble, selected with a proprietary model. Recent pilot- and full-scale demonstrations in pulverized-coal (PC) and circulating fluidized bed (CFB) boilers suggest that these patented sorbents outperform conventional limestone for the simultaneous control of SOx, NOx, and particulates during the combustion of coal and sulfur-rich fuels, such as oil, mixed municipal waste and used tires. Dubbed thermally active marbles (TAMs), these sorbents are chemically identical to grainy limestone (whose main constituent is calcium carbonate or calcite). However, thanks to the increased pressures and temperatures experienced during their geologic history, these metamorphic minerals have a regular crystalline structure that offers some advantages in the combustion zone. TAMs, on the other hand, enjoy better calcium-utilization rates because upon heating, they cleave along inter- and intra-crystalline faces, continuously exposing fresh surfaces. By minimizing the self-extinguishment suffered by limestone sorbents, TAMs are effective over operating temperatures from 1,200 F to 2,800 F, which is 400 F higher than other calcium-based sorbents. This allows them to be injected closer to the burner or combustion grate to maximize residence time in the unit.

  1. Recovery and recycling of limestone in LEC flue gas desulfurization

    SciTech Connect

    Gardner, N.C.; Boo, J.Y.; Culver, L. )

    1992-09-01

    Prudich et. al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases on contact. Sulfite and sulfate salts deposit on the surface of the particles; however, the gas never reaches the interior, limiting the limestone utilization to approximately 20% or less. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economics are derived from small equipment, simplicity, and low sorbent costs. This project is a wet method for grinding and recovering the spent limestone from the LEC process, utilizing an impeller fluidizer, a new type of slurry processor. It consists of a cylindrical vessel with an impeller at one end. The impeller, driven at high rpm, concentrates the gravel size limestone in a rotating torus at the top of the cylinder, where the coating is abraded off by particle-particle impaction. The impeller generates sufficient pressure head to serve as a slurry pump. It combines the operation of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry. The fluidizer may be advantageous over dry grinding in the aspects of sharpness of separation, transport convenience, equipment erosion, and sorption bed cementation.

  2. Field evaluation of natural gas and dry sorbent injection for MWC emissions control

    SciTech Connect

    Wohadlo, S; Abbasi, H; Cygan, D

    1993-10-01

    The Institute of Gas Technology (IGT), in cooperation with the Olmsted Waste-to-Energy Facility (OWEF) and with subcontracted engineering services from the Energy and Environmental Research Corporation (EER), has completed the detailed engineering and preparation of construction specifications for an Emissions Reduction Testing System (ERTS). The ERTS has been designed for retrofit to one of two 100-ton/day municipal waste combustors at the OWEF, located in Rochester, Minnesota. The purpose of the retrofit is to conduct a field evaluation of a combined natural gas and sorbent injection process (IGT`s METHANE de-TOX{sup SM}, IGT Patent No. 5,105,747) for reducing the emissions of oxides of nitrogen (NO{sub x}), hydrochloric acid (HCI), oxides of sulfur (SO{sub x}), carbon monoxide (CO), total hydrocarbons (THC), and chlorinated hydrocarbons (dioxin/furans). In addition, the design includes modifications for the control of heavy metals (HM). Development of the process should allow the waste-to-energy industry to meet the Federal New Source Performance Standards for these pollutants at significantly lower costs when compared to existing technology of Thermal deNO{sub x} combined with spray dryer scrubber/fabric filters. Additionally, the process should reduce boiler corrosion and increase both the thermal and power production efficiency of the facility.

  3. Evaluation of Dry Sorbent Injection Technology for Pre-Combustion CO{sub 2} Capture

    SciTech Connect

    Richardson, Carl; Steen, William; Triana, Eugenio; Machalek, Thomas; Davila, Jenny; Schmit, Claire; Wang, Andrew; Temple, Brian; Lu, Yongqi; Lu, Hong; Zhang, Luzheng; Ruhter, David; Rostam-Abadi, Massoud; Sayyah, Maryam; Ito, Brandon; Suslick, Kenneth

    2013-09-30

    This document summarizes the work performed on Cooperative Agreement DE-FE0000465, “Evaluation of Dry Sorbent Technology for Pre-Combustion CO{sub 2} Capture,” during the period of performance of January 1, 2010 through September 30, 2013. This project involves the development of a novel technology that combines a dry sorbent-based carbon capture process with the water-gas-shift reaction for separating CO{sub 2} from syngas. The project objectives were to model, develop, synthesize and screen sorbents for CO{sub 2} capture from gasified coal streams. The project was funded by the DOE National Energy Technology Laboratory with URS as the prime contractor. Illinois Clean Coal Institute and The University of Illinois Urbana-Champaign were project co-funders. The objectives of this project were to identify and evaluate sorbent materials and concepts that were suitable for capturing carbon dioxide (CO{sub 2}) from warm/hot water-gas-shift (WGS) systems under conditions that minimize energy penalties and provide continuous gas flow to advanced synthesis gas combustion and processing systems. Objectives included identifying and evaluating sorbents that efficiently capture CO{sub 2} from a gas stream containing CO{sub 2}, carbon monoxide (CO), and hydrogen (H{sub 2}) at temperatures as high as 650 °C and pressures of 400-600 psi. After capturing the CO{sub 2}, the sorbents would ideally be regenerated using steam, or other condensable purge vapors. Results from the adsorption and regeneration testing were used to determine an optimal design scheme for a sorbent enhanced water gas shift (SEWGS) process and evaluate the technical and economic viability of the dry sorbent approach for CO{sub 2} capture. Project work included computational modeling, which was performed to identify key sorbent properties for the SEWGS process. Thermodynamic modeling was used to identify optimal physical properties for sorbents and helped down-select from the universe of possible sorbent

  4. Effects of limestone on the dissolution of phosphate from sediments under anaerobic condition.

    PubMed

    Kim, H S; Park, J

    2008-04-01

    This paper describes a study on the role of limestone on the dissolution of phosphates when phosphate-containing sediments are put under anaerobic conditions. Anaerobic decomposition of organic substances produces both organic acids and carbonic acids which in turn could accelerate the dissolution of the phosphates. If limestone coexisted, both phosphate and limestone would compete as receptors of hydrogen ions so as to affect the dissolution of phosphate. A small quantity of calcium hydroxyapatite, alone or mixed with limestone powder, was put in contact with an aqueous solution of acetic acid or carbonic acid and the variations in phosphate concentration were determined over time. The results showed that the phosphate concentration was remarkably low in the case of limestone presence, in comparison with the case of limestone absence. This signifies that the coexistence of limestone suppresses the dissolution of phosphate by organic acid and/or carbonic acid. Separate experiments conducted by developing an anaerobic condition, after mixing lake sediments with dried leaves and limestone, allowed us to observe that the existence of limestone suppressed the dissolution of phosphate. It seems that the limestone acts as a material sacrificing to the leaching of hydrogen ions from the acids produced under anaerobic conditions. These results show that the application of limestone might be a useful measure to prevent deterioration of water quality through eutrophication, by breaking the internal loading of phosphates in eutrophic water bodies. PMID:18619142

  5. Investigation of the chemical pathway of gaseous nitrogen dioxide formation during flue gas desulfurization with dry sodium bicarbonate injection

    NASA Astrophysics Data System (ADS)

    Stein, Antoinette Weil

    The chemical reaction pathway for the viable flue gas desulfurization process, dry sodium bicarbonate injection, was investigated to mitigate undesirable plume discoloration. Based on a foundation of past findings, a simplified three-step reaction pathway was hypothesized for the formation of the plume-discoloring constituent, NO2. As the first step, it was hypothesized that sodium sulfite formed by sodium bicarbonate reaction with flue gas SO 2. As the second step, it was hypothesized that sodium nitrate formed by sodium sulfite reaction with flue gas NO. And as the third step, it was hypothesized that NO2 and sodium sulfate formed by sodium nitrate reaction with SO2. The second and third hypothesized steps were experimentally investigated using an isothermal fixed bed reactor. As reported in the past, technical grade sodium sulfite was found to be un-reactive with NO and O2. Freshly prepared sodium sulfite, maintained unexposed to moist air, was shown to react with NO and O2 resulting in a mixture of sodium nitrite and sodium nitrate together with a significant temperature rise. This reaction was found to proceed only when oxygen was present in the flue gas. As reported in the past, technical grade sodium nitrate was shown to be un-reactive with SO2. But freshly formed sodium nitrate kept unexposed to humidity was found to be reactive with SO2 and O 2 resulting in the formation of NO2 and sodium sulfate polymorphic Form I. The NO2 formation by this reaction was shown to be temperature dependent with maximum formation at 175°C. Plume mitigation methods were studied based on the validated three-step reaction pathway. Mitigation of NO2 was exhibited by limiting oxygen concentration in the flue gas to a level below 5%. It was also shown that significant NO2 mitigation was achieved by operating below 110°C or above 250°C. An innovative NO2 mitigation method was patented as a result of the findings of this study. The patented process incorporated a process step of

  6. Integrated dry NO{sub x}/SO{sub 2} emissions control system sodium-based dry sorbent injection test report. Test period: August 4, 1993--July 29, 1995

    SciTech Connect

    Smith, R.A.; Shimoto, G.H.; Muzio, L.J.; Hunt, T.

    1997-04-01

    The project goal is to demonstrate up to 70% reductions in NOx and SO{sub 2} emissions through the integration of: (1) down-fired low-NOx burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NOx removal; and (3) dry sorbent injection and duct humidification for SO{sub 2} removal. This report documents the sixth phase of the test program, where the performance of dry sorbent injection with sodium compounds was evaluated as a SO{sub 2} removal technique. Dry sorbent injection was performed in-duct downstream of the air heater (ahead of the fabric filter), as well as at a higher temperature location between the economizer and air heater. Two sodium compounds were evaluated during this phase of testing: sodium sesquicarbonate and sodium bicarbonate. In-duct sodium injection with low levels of humidification was also investigated. This sixth test phase was primarily focused on a parametric investigation of sorbent type and feed rate, although boiler load and sorbent preparation parameters were also varied.

  7. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  8. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  9. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially (not less than 94 percent... occurring limestone. (b) The ingredient meets the specifications of the Food Chemicals Codex, 3d Ed....

  10. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  11. 21 CFR 184.1409 - Ground limestone.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ground limestone. 184.1409 Section 184.1409 Food... Specific Substances Affirmed as GRAS § 184.1409 Ground limestone. (a) Ground limestone consists essentially... classifying of naturally occurring limestone. (b) The ingredient meets the specifications of the...

  12. Inductively coupled plasma mass spectrometry with a twin quadrupole instrument using laser ablation sample introduction and monodisperse dried microparticulate injection

    SciTech Connect

    Allen, L.A.

    1997-02-01

    The focus of this dissertation is the use of a twin quadrupole inductively coupled plasma mass spectrometer (ICP-MS) for the simultaneous detection of two m/z values. The twin quadrupole ICP-MS is used with laser ablation sample introduction in both the steady state (10 Hz) and single pulse modes. Steady state signals are highly correlated and the majority of flicker noise cancels when the ratio is calculated. Using a copper sample, the isotope ratio {sup 63}Cu{sup +}/{sup 65}Cu{sup +} is measured with a relative standard deviation (RSD) of 0.26%. Transient signals for single laser pulses are also obtained. Copper isotope ratio measurements for several laser pulses are measured with an RSD of 0.85%. Laser ablation (LA) is used with steel samples to assess the ability of the twin quadrupole ICP-MS to eliminate flicker noise of minor components of steel samples. Isotopic and internal standard ratios are measured in the first part of this work. The isotope ratio {sup 52}Cr{sup +}/{sup 53}Cr{sup +} (Cr present at 1.31 %) can be measured with an RSD of 0.06 % to 0.1 %. For internal standard elements, RSDs improve from 1.9 % in the Cr{sup +} signal to 0.12% for the ratio of {sup 51}V{sup +} to {sup 52}Cr{sup +}. In the second part of this work, one mass spectrometer is scanned while the second channel measures an individual m/z value. When the ratio of these two signals is calculated, the peak shapes in the mass spectrum are improved significantly. Pulses of analyte and matrix ions from individual drops are measured simultaneously using the twin quadrupole ICP-MS with monodisperse dried microparticulate injection (MDMI). At modest Pb concentrations (500 ppm), a shoulder on the leading edge of the Li{sup +} signal becomes apparent. Space charge effects are consistent with the disturbances seen.

  13. Effects of brine injection wells, dry holes, and plugged oil/gas wells on chloride, bromide, and barium concentrations in the Gulf Coast Aquifer, southeast Texas, USA.

    PubMed

    Hudak, P F; Wachal, D J

    2001-06-01

    Data from 1,122 brine injection wells, 24,515 dry holes, 20,877 plugged oil/gas wells, and 256 water wells were mapped with a geographic information system (GIS) and statistically analyzed. There were 9, 107, and 58 water wells within 750 m of a brine injection well, dry hole, or plugged oil/gas well, respectively. Computed median concentrations were 157 mg/l for chloride, 0.8 mg/l for bromide, and 169 microg/l for barium. The maximum chloride concentration was 2,384 mg/l, close to 10 times the secondary drinking water standard. Shallow water wells and water wells near plugged oil/gas wells had significantly higher chloride and bromide levels.

  14. Effects of brine injection wells, dry holes, and plugged oil/gas wells on chloride, bromide, and barium concentrations in the Gulf Coast Aquifer, southeast Texas, USA.

    PubMed

    Hudak, P F; Wachal, D J

    2001-06-01

    Data from 1,122 brine injection wells, 24,515 dry holes, 20,877 plugged oil/gas wells, and 256 water wells were mapped with a geographic information system (GIS) and statistically analyzed. There were 9, 107, and 58 water wells within 750 m of a brine injection well, dry hole, or plugged oil/gas well, respectively. Computed median concentrations were 157 mg/l for chloride, 0.8 mg/l for bromide, and 169 microg/l for barium. The maximum chloride concentration was 2,384 mg/l, close to 10 times the secondary drinking water standard. Shallow water wells and water wells near plugged oil/gas wells had significantly higher chloride and bromide levels. PMID:11485217

  15. Scaling on a limestone flooring

    NASA Astrophysics Data System (ADS)

    Carmona-Quiroga, P. M.; Blanco-Varela, M. T.; Martínez-Ramírez, S.

    2012-04-01

    Natural stone can be use on nearly every surface, inside and outside buildings, but decay is more commonly reported from the ones exposed to outdoor aggressively conditions. This study instead, is an example of limestone weathering of uncertain origin in the interior of a residential building. The stone, used as flooring, started to exhibit loss of material in the form of scaling. These damages were observed before the building, localized in the South of Spain (Málaga), was inhabited. Moreover, according to the company the limestone satisfies the following European standards UNE-EN 1341: 2002, UNE-EN 1343: 2003; UNE-EN 12058: 2004 for floorings. Under these circumstances the main objective of this study was to assess the causes of this phenomenon. For this reason the composition of the mortar was determined and the stone was characterized from a mineralogical and petrological point of view. The last material, which is a fossiliferous limestone from Egypt with natural fissure lines, is mainly composed of calcite, being quartz, kaolinite and apatite minor phases. Moreover, under different spectroscopic and microscopic techniques (FTIR, micro-Raman, SEM-EDX, etc) samples of the weathered, taken directly from the buildings, and unweathered limestone tiles were examined and a new mineralogical phase, trona, was identified at scaled areas which are connected with the natural veins of the stone. In fact, through BSE-mapping the presence of sodium has been detected in these veins. This soluble sodium carbonate would was dissolved in the natural waters from which limestone was precipitated and would migrate with the ascendant capilar humidity and crystallized near the surface of the stone starting the scaling phenomenon which in historic masonry could be very damaging. Therefore, the weathering of the limestone would be related with the hygroscopic behaviour of this salt, but not with the constructive methods used. This makes the limestone unable to be used on restoration

  16. Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes. Volume 1, Dry sorbent injection: Final report

    SciTech Connect

    Jozewicz, W.; Rochelle, G.T.

    1992-01-29

    This report presents the results of fundamental mass transfer testing for in-duct removal of SO{sub 2}. Following this initial part of an experimental program, it became clear that the amount of initial moisture on the sorbent strongly affected the extent of Ca(OH){sub 2} conversion. Novel techniques aimed at increasing sorbent utilization were investigated and are described. Major novel technique investigated and reported on here was the reaction with SO{sub 2} of sorbents with initial free moisture (damp sorbents). The duct injection process using damp solids has the following steps: preparation of sorbent as a slurry, blending of the slurry with dry recycle materials to create damp solids, injection of the solids into the duct, reaction and drying of the solids with flue gas in the duct, collection in particulate control equipment, and finally recycle of dry solids with some bleed to disposal. The moisture content of the solids at each step affects system performance. Various factors favor high moisture whereas others favor low moisture. (VC)

  17. Paleozoic Hydrocarbon-Seep Limestones

    NASA Astrophysics Data System (ADS)

    Peckmann, J.

    2007-12-01

    To date, five Paleozoic hydrocarbon-seep limestones have been recognized based on carbonate fabrics, associated fauna, and stable carbon isotopes. These are the Middle Devonian Hollard Mound from the Antiatlas of Morocco [1], Late Devonian limestone lenses with the dimerelloid brachiopod Dzieduszyckia from the Western Meseta of Morocco [2], Middle Mississippian limestones with the dimerelloid brachiopod Ibergirhynchia from the Harz Mountains of Germany [3], Early Pennsylvanian limestones from the Tantes Mound in the High Pyrenees of France [4], and Late Pennsylvanian limestone lenses from the Ganigobis Shale Member of southern Namibia [5]. Among these examples, the composition of seepage fluids varied substantially as inferred from delta C-13 values of early diagenetic carbonate phases. Delta C-13 values as low as -50 per mil from the Tantes Mound and -51 per mil from the Ganigobis limestones reveal seepage of biogenic methane, whereas values of -12 per mil from limestones with Dzieduszyckia associated with abundant pyrobitumen agree with oil seepage. Intermediate delta C-13 values of carbonate cements from the Hollard Mound and Ibergirhynchia deposits probably reflect seepage of thermogenic methane. It is presently very difficult to assess the faunal evolution at seeps in the Paleozoic based on the limited number of examples. Two of the known seeps were typified by extremely abundant rhynchonellide brachiopods of the superfamily Dimerelloidea. Bivalve mollusks and tubeworms were abundant at two of the known Paleozoic seep sites; one was dominated by bivalve mollusks (Hollard Mound, Middle Devonian), another was dominated by tubeworms (Ganigobis Shale Member, Late Pennsylvanian). The tubeworms from these two deposits are interpreted to represent vestimentiferan worms, based on studies of the taphonomy of modern vestimentiferans. However, this interpretation is in conflict with the estimated evolutionary age of vestimentiferans based on molecular clock methods

  18. Effect of additive gases and injection methods on chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F{sub 2} remote plasmas

    SciTech Connect

    Yun, Y. B.; Park, S. M.; Kim, D. J.; Lee, N.-E.; Kim, K. S.; Bae, G. H.

    2007-07-15

    The authors investigated the effects of various additive gases and different injection methods on the chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F{sub 2} remote plasmas. N{sub 2} and N{sub 2}+O{sub 2} gases in the F{sub 2}/Ar/N{sub 2} and F{sub 2}/Ar/N{sub 2}/O{sub 2} remote plasmas effectively increased the etch rate of the layers. The addition of direct-injected NO gas increased the etch rates most significantly. NO radicals generated by the addition of N{sub 2} and N{sub 2}+O{sub 2} or direct-injected NO molecules contributed to the effective removal of nitrogen and oxygen in the silicon nitride and oxide layers, by forming N{sub 2}O and NO{sub 2} by-products, respectively, and thereby enhancing SiF{sub 4} formation. As a result of the effective removal of the oxygen, nitrogen, and silicon atoms in the layers, the chemical dry etch rates were enhanced significantly. The process regime for the etch rate enhancement of the layers was extended at elevated temperature.

  19. Structural studies in limestone sulfidation

    SciTech Connect

    Fenouil, L.A.; Lynn, S.

    1993-05-01

    This study investigates the sulfidation of limestone at high temperatures (700--900{degree}C) as the first step in the design of a High-Temperature Coal-Gas Clean-Up system using millimeter-size limestone particles. Several workers have found that the rate of this reaction significantly decreases after an initial 10 to 15% conversion of CaCO{sub 3} to CaS. The present work attempts to explain this feature. It is first established that millimeter-size limestone particles do not sinter at temperatures up to the CaCO{sub 3} calcination point (899{degree}C at 1.03 bar CO{sub 2} partial pressure). It is then shown that CaS sinters rapidly at 750 to 900{degree}C if CO{sub 2} is present in the gas phase. Scanning Electron Microscope (SEM) photographs and Electron Dispersive Spectroscopy (EDS) data reveal that the CaS product layer sinters and forms a quasi-impermeable coating around the CaCO{sub 3} grains that greatly hinders more H{sub 2}S from reaching the still unreacted parts of the stone. Moreover, most of the pores initially present within the limestone structure begin to disappear or, at least, are significantly reduced in size. From then on, subsequent conversion is limited by diffusion of H{sub 2}S through the CaS layer, possibly by S{sup 2{minus}} ionic diffusion. The kinetics is then adequately described by a shrinking-core model, in which a sharp front of completely converted limestone is assumed to progress toward the center of the pellet. Finally, experimental evidence and computer simulations using simple sintering models suggest that the CaS sintering, responsible for the sharp decrease in the sulfidation rate, is surface-diffusion controlled.

  20. Pilot-scale limestone emission control (LEC) process: A development project. Volume 1: Main report and appendices A, B, C, and D. Final report

    SciTech Connect

    Not Available

    1994-03-01

    ETS, Inc., a pollution consulting firm with headquarters in Roanoke, Virginia, has developed a dry, limestone-based flue gas desulfurization (FGD) system. This SO{sub 2} removal system, called Limestone Emission Control (LEC), can be designed for installation on either new or existing coal-fired boilers. In the LEC process, the SO{sub 2} in the flue gas reacts with wetted granular limestone that is contained in a moving bed. A surface layer of principally calcium sulfate (CaSO{sub 4}) is formed on the limestone. Periodic removal of this surface layer by mechanical agitation allows high utilization of the limestone granules. The primary goal of the current study is the demonstration of the techno/economic capability of the LEC system as a post-combustion FGD process capable of use in both existing and future coal-fired boiler facilities burning high-sulfur coal. A nominal 5,000 acfm LEC pilot plant has been designed, fabricated and installed on the slipstream of a 70,000 pph stoker boiler providing steam to Ohio University`s Athens, Ohio campus. The pilot plant was normally operated on the slipstream of the Ohio Univ. boiler plant flue gas, but also had the capability of operating at higher inlet SO{sub 2} concentrations (typically equivalent to 3-1/2% sulfur coal) than those normally available from the flue gas slipstream. This was accomplished by injecting SO{sub 2} gas into the slipstream inlet. The pilot plant was instrumented to provide around-the-clock operation and was fully outfitted with temperature, SO{sub 2}, gas flow and pressure drop monitors.

  1. CALCIUM CARBONATE DISSOLUTION RATE IN LIMESTONE CONTACTORS

    EPA Science Inventory

    The rate of carbonate mineral dissolution from limestone was studied using a rotating disk apparatus and samples of limestone of varied composition. The purpose of this study was to determine the effect of limestone composition on the kinetics of carbonate mineral dissolution. Th...

  2. Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly technical report, July 1, 1996--September 31, 1996

    SciTech Connect

    Hunt, T.; Sjostrom, S.; Smith, J.

    1996-11-06

    The overall objective of this two phase program is to investigate the use of dry carbon-based sorbents for mercury control. This information is important to the utility industry in anticipation of pending regulations. During Phase I, a bench-scale field test device that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse has been designed, built and integrated with an existing pilot-scale facility at PSCo`s Comanche Station. Up to three candidate sorbents will be injected into the flue gas stream upstream of the test device to and mercury concentration measurements will be made to determine the mercury removal efficiency for each sorbent. During the Phase II effort, component integration for the most promising dry sorbent technology shall be tested at the 5000 acfm pilot-scale.

  3. Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly report, November 1, 1995--December 31, 1995

    SciTech Connect

    Hunt, T.; Sjostrom, S.

    1996-02-05

    The overall objective to this two phase program is to investigate dry carbon-based sorbents for mercury control. During Phase I, a bench-scale field test device that can simulate an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse will be designed and integrated with an existing pilot-scale facility at Public Service Company of Colorado`s (PSCo`s) Comanche station. Various sorbents will then be injected to determine the mercury removal efficiency for each. During Phase II effort, component integration of the most promising technologies shall be tested at the 5000 acfm pilot-scale. The primary task currently underway is the facility design. The design is expected to be finished in January, 1996. The facility, regardless of the particulate control module configuration, will be fitted with supply line injection port, through which mercury sorbents and SO{sub 2} control sorbents can be added to the flue gas stream.

  4. LIFAC Sorbent Injection Desulfurization Demonstration Project

    SciTech Connect

    Not Available

    1992-01-01

    Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers -- and requires more reagent material. However, if the demonstration is wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems. LIFAC is less expensive to install than conventional wet FGD processes. LIFAC's overall costs measured on a dollar-per-ton SO[sub 2] removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product. LIFAC is relatively simple to operate.

  5. Water transport in limestone by X-ray CAT scanning

    USGS Publications Warehouse

    Mossoti, Victor G.; Castanier, Louis M.

    1989-01-01

    The transport of water through the interior of Salem limestone test briquettes can be dynamically monitored by computer aided tomography (commonly called CAT scanning in medical diagnostics). Most significantly, unless evaporation from a particular face of the briquette is accelerated by forced air flow (wind simulation), the distribution of water in the interior of the briquette remains more or less uniform throughout the complete drying cycle. Moreover, simulated solar illumination of the test briquette does not result in the production of significant water gradients in the briquette under steady-state drying conditions.

  6. Experimental investigation of high-temperature, short residence-time calcination and sulfation of limestone and dolostone sorbents

    SciTech Connect

    Hu, Naiya; Miller, S.F.; Scaroni, A.W.

    1994-12-31

    Sulfur dioxide emissions from coal-fired utility boilers and furnaces continue to be of significant regulatory concern. One approach to reducing these emissions that has received considerable attention is the injection of dry, pulverized sorbent (limestone or dolostone) into the combustion chamber. This technology has been applied to conventional coal-fired utility boilers and is considered to be a good candidate for use in coal-fired heat engine applications. During the process, the injected limestone or dolostone particles are rapidly heated by the hot combustion gases and calcined by the reactions CaCO{sub 3} {yields} CaO + CO{sub 2} and CaMg(CO{sub 3}){sub 2} {yields} CaO + MgO + 2CO{sub 2}, respectively. The CaO produced then reacts with SO{sub 2} and excess O{sub 2} in the combustion gases to form CaSO{sub 4}. Experimental data on the rates of calcination, sintering and sulfation have been reported by Borgwardt and others. The physical structure of the calcined sorbents has also been investigated and a number of models have been developed describing the calcination and sulfation processes. The primary application of dry sorbent injection is to conventional coal-fired utility boilers. The sorbent particle size used is either small (in the range of 1 to 30 {mu}m) in pulverized coal applications or large (in the range of 0.25 to 1 mm) for fluidized-bed applications. Few investigations have been carried out using 30 to 100 {mu}m particles, which is the size range of interest for coal-fired heat engine applications. This study investigated the calcination and sulfation behavior of three different sorbents (two limestones and one dolostone) in the size range from 37 to 105 {mu}m. The time required for heating and calcination, the effect of the calcination process on sulfation behavior, and the effect of sorbent type on sulfation behavior were of primary interest.

  7. Geochemistry of laboratory anoxic limestone drains

    SciTech Connect

    Sterner, P.; Skousen, J.; Donovan, J.

    1998-12-31

    An anoxic limestone drain (ALD) is a passive treatment system for treating acid mine drainage (AMD). Historically it has been thought that AMD containing Fe{sup 3+} and Al{sup 3+} severely inhibits or stops limestone dissolution due to coating of limestone surfaces by precipitates generated during the neutralization process. Limestone dissolution in field ALDs is difficult to quantify because sampling of the water in ALDs at various locations is not possible, and fluctuations in flow and water chemistry affect limestone dissolution rates. Laboratory experiments were developed to determine the effects of Fe{sup 3+} and Al{sup 3+} precipitation on limestone dissolution and the controlling precipitation reactions. Synthetic AMD containing Fe{sup 3+} or Al{sup 3+} with and without sulfate was pumped through limestone-packed columns constructed with three sampling ports at equidistant intervals along the column. Water and sediments were periodically extracted for analysis at all sampling ports over a 12-hr period. Results show the majority of limestone dissolution occurred within the first 1.2 hrs of water-limestone contact. Limestone dissolution rate decreased with time and distance along the flow path. Higher concentrations of Fe{sup 3+} and Al{sup 3+} (increased in mineral acidity and ionic strength) enhanced limestone dissolution. Geochemical modeling predicted that solutions were nearest equilibrium with respect to the amorphic metal hydroxide phases. Although solutions were periodically oversaturated with respect to sulfate containing minerals, but no x-ray identifiable sulfate minerals were found in the solid phase. The data suggest that smaller anoxic limestone drains may be used when the goal is to neutralize mineral acidity, thus reducing spatial requirements. However, if the goal is to treat AMD to NPDES limits, ALDs may not be a viable long term treatment alternative.

  8. Nanoscale surface characterization and miscibility study of a spray-dried injectable polymeric matrix consisting of poly(lactic-co-glycolic acid) and polyvinylpyrrolidone.

    PubMed

    Meeus, Joke; Chen, Xinyong; Scurr, David J; Ciarnelli, Valeria; Amssoms, Katie; Roberts, Clive J; Davies, Martyn C; van Den Mooter, Guy

    2012-09-01

    Injectable controlled-release formulations are of increasing interest for the treatment of chronic diseases. This study aims to develop and characterize a polymeric matrix for intramuscular or subcutaneous injection, consisting of two biocompatible polymers, particularly suitable for formulating poorly soluble drugs. For this matrix, the water-insoluble polymer poly(lactic-co-glycolic acid) (PLGA) is combined with the water-soluble polymer polyvinylpyrrolidone (PVP). Microparticles of these two polymers were prepared by spray drying. The phase behavior of the samples was studied by means of modulated differential scanning calorimetry and the results showed that phase separation occurred in the bulk sample through evidence of two mixed amorphous phases, namely, a PLGA-rich phase and a PVP-rich phase. Characterization of the samples by scanning electron microscopy demonstrated that the spray-dried particles were hollow with a thin shell. Because of the importance in relation to stability and drug release, information about the surface of the microparticles was collected by different complementary surface analysis techniques. Atomic force microscopy gathered information about the morphology and phase behavior of the microparticle surface. Time-of-flight secondary ion mass spectrometry analysis of the particles revealed that the surface consisted mainly of the PLGA-rich phase. This was confirmed by X-ray photoelectron spectroscopy at an increased sampling depth (≈ 10 nm). Nanothermal analysis proved to be an innovative way to thermally detect the presence of the PLGA-dominated surface layer and the underlying PVP phase. Taken together, this information provides a rational basis for predicting the likely drug release behavior this formulation will display.

  9. On the failure mode in dry and hygrothermally aged short fiber-reinforced injection-molded polyarylamide composites by acoustic emission

    NASA Astrophysics Data System (ADS)

    Czigány, T.; Mohd Ishak, Z. A.; Karger-Kocsis, J.

    1995-09-01

    The failure mode in injection-molded short glass (GF) and carbon fiber (CF) reinforced polyarylamide (PAR) composites was studied on compact tension (CT) specimens in as-received (AR), hygrothermally aged (HA) and re-dried (RD) states, respectively, using acoustic emission (AE) and fractography. A significant difference was revealed in the failure manner characterized by the cumulative run, amplitude and energy distribution of the AE events as a function of the water content of the composites. Furthermore, a correlation was found between the cumulative AE events up to the maximum load and the fracture toughness of the composites. It was shown that the fracture response and thus the failure behavior of the water-saturated PAR composites can be restored by drying. This fact indicates that the water absorption and desorption are of a purely physical nature, i.e. they are reversible processes. It was established that chopped fiber-reinforced PAR composites fail by matrix deformation along with fiber/matrix debonding in the crack initiation, whereas fiber pull-out becomes dominant in the crack propagation range. Water uptake shifts both the AE amplitude and energy curves toward lower values, a phenomenon attributed to plastification of the PAR matrix by water.

  10. Field Test of Limestone as a Treatment Medium for Groundwater at the Savannah River Site

    SciTech Connect

    Ekechukwu, A.A.

    2001-04-10

    Groundwater downgradient from the F- and H-Area Seepage Basins at the Savannah River Site is contaminated with acids, metals, radionuclides, and tritium originally released as part of low-level waste streams from the Radiochemical Separations Areas processing facilities. To stem the flux of tritium discharged from the basin area, a series of wells was installed to extract the groundwater and re-inject it upgradient of the seepage basins. Tritium is captured in an extraction-re-injection cycle that allows it to decay. To meet regulatory criteria for re-injection, metals and radionuclides must be treated and removed. One method under consideration for this removal is in-situ contact with limestone. Equilibration of the groundwater with limestone raises the pH to approximately 8. At this pH, metals and radionuclides can be removed by direct precipitation, co-precipitation, and enhanced adsorption. A pilot test was performed to provide data required to assess the applicability of limestone in groundwater treatment. The demonstration unit consisted of several columns of limestone with different total column lengths and thus different residence times. Ground water from the basins was passed through each of the columns and analyzed for metals, radionuclides, ions, pH, and alkalinity. The results from both the laboratory and field tests show the limestone's effectiveness as an in-situ treatment medium.

  11. Effect of an acid rain environment on limestone surfaces

    SciTech Connect

    Mossotti, V.G.; Lindsay, J.R.; Hochella, M.F. Jr.

    1987-11-01

    As part of a study to assess mineralogical alterations in building stone caused by acid rain, Salem limestone samples were exposed for one year in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone (control material). All samples collected from urban exposure sites developed gypsum stains on the grounding surfaces, where the stones were unwashed by precipitation. However, the bulk chemistry of the urban samples (not including the stain) was virtually identical to that of the control stone. Sulfur (in the form of sulfate) was disseminated over the calcite grain surfaces to a depth less than 10 nanometer in the freshly quarried limestone; an identical sulfate layer was found on the calcite grains after the 1-y exposure period. Mass balance calculations and sulfur isotope patterns indicate that the gypsum stain on the protected surfaces consists of adventitious sulfur. A model, involving the attack of SO/sub 2/ on dry calcite, was used to define the conditions for stain formation on dry, protected surfaces. This suggests that under arid conditions, once the surface has been saturated with gypsum, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO/sub 2/ concentration. On rain-washed surfaces experiencing gas-solid attack during intermittent dry periods, the quantity of gypsum produced by a gas-solid reaction mechanism should strongly correlate with both the frequency of rain events and the atmospheric SO/sub 2/ level, provided that the rain events are frequent and clearly delimited by periods of dryness.

  12. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, G.H.; Knauss, K.G.; Langer, W.H.; Caldeira, K.

    2004-01-01

    The climate and environmental impacts of the current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. A discussion on CO2 mitigation via accelerated limestone weathering covers limestone and seawater availability and cost; reaction rates and densities; effectiveness in CO2 sequestration; and environmental impacts and benefits.

  13. Sodium-limestone double alkali flue gas desulfurization process with improved limestone utilization

    SciTech Connect

    Biolchini, R.J.; Boward, W.L. Jr.; Wang, K.H.

    1987-08-18

    This patent describes a sodium-limestone double alkali process for the continuous desulfurization of flue gas, having the steps of absorbing sulfur dioxide from an SO/sub 2/-containing gas stream in an absorber with an aqueous solution of sodium sulfite and sodium bisulfite, diverting at least a portion of the absorber effluent solution for regeneration with limestone, introducing limestone into the diverted absorber effluent solution to convert bisulfite to sulfite, separating by-product solids from the limestone-treated solution, and returning regenerated solution to the absorber, the improvement for increasing the utilization of the limestone used during the regeneration operation.

  14. Recovery and recycling of limestone in LEC flue gas desulfurization. Final report, June 1, 1990--August 31, 1991

    SciTech Connect

    Gardner, N.C.; Adler, R.J.; Lin, Y.C.; Unger, M.E.; Lux, K.W.

    1992-03-01

    Prudich et al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases. Sulfates and sulfites deposit on the surfaces of the particles, limiting their utilization to about 20%. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economic costs derive from small equipment, simplicity, and low sorbent cost. Our research concentrates on selecting and testing on a laboratory scale suitable candidate dry and wet grinding methods for recovering limestone in LEC flue from desulfurization. A wet grinding method based on the impeller fluidizer, a new type of slurry processor, receives special attention. The impeller fluidizer is a dosed cylindrical vessel with an impeller at one end. It combines the operations of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry.

  15. Origin and Age of the Yemi Limestone Breccia, Korea

    NASA Astrophysics Data System (ADS)

    KOH, Hee Jae

    2015-04-01

    were filled and injected by sandy and muddy material of the BG. These kinds of evidence of indicate that Type-II carbonate breccia is a product of post-orogenic solution-collapsed brecciation in karst platform framed during exposure in surface through uplift after ductile deformation. The age can be constrained from Karstification of limestone after ductile deformation (the Middle Triassic Indosinian orogeny) to beginning stage of the sedimentation of the BG. Conclusively the YLB has to be re-defined as Type-II carbonate breccia with difference of composition and deformation characteristics between breccia and matrix, except Type-I carbonate breccia belonging to the CS stratigraphically.

  16. Novel preparation method of macroporous lime from limestone for high-temperature desulfurization

    SciTech Connect

    Sasaoka, Eiji; Uddin, M.A.; Nojima, Shigeru

    1997-09-01

    Limestone is a very important material as a high temperature desulfurization sorbent: limestone is used for in-bed SO{sub 2} capture in fluidized bed combustors of coal and can be used in coal gasifiers for the in-bed removal of H{sub 2}S. In order to develop a highly active calcium oxide high-temperature desulfurization sorbent, macroporous calcium oxides were directly prepared from limestone. This method is composed of two steps: swelling of the limestone in the gas phase followed by drying and calcination of the swelled samples. The swelling was found when limestone was exposed to a vapor of aqueous acetic acid. The swelling of the sample resulted from an increase of calcium acetate formation in the sample. It was then converted to macroporous calcium oxides by heating the sample to 850 C. The reactivity of the macroporous calcium oxide for the removal of SO{sub 2} or H{sub 2}S under coexisting H{sub 2}O vapor was higher than that of the calcined raw limestone. In particular, its SO{sub 2} removal capacity and oxidative character of CaS to CaSO{sub 4} and CaO were greatly improved by the swelling method.

  17. Regeneration of sulfated dolomite and limestone by reductive decomposition

    SciTech Connect

    Ersoy-Mericboyu, A.; Karatepe, N.; Kuecuekbayrak, S.; Kafa, S.; Guersoy, G.

    1999-08-01

    Regeneration properties of sulfated dolomite and limestone samples were investigated. Natural stones were first fully calcined at 1223 K in a gaseous atmosphere consisting of CO{sub 2} 15 vol. % and dry air 85 vol. %; second, sulfation of the calcines was achieved by reacting them with a gaseous mixture consisting of CO{sub 2} 15 vol. %, SO{sub 2} 0.35 vol. %, and a balance of dry air at 1223 K; last, sulfated calcines were regenerated at 1373 K by a reductive decomposition process. During regeneration a 3:1 volumetric ratio of CO{sub 2}/CO was maintained in the reducing gaseous atmosphere to minimize CaS formation. It has been found that for the five sulfation-generation cycles the reactivity of the limestone and dolomite samples remained at acceptable levels. Since the repeated sulfation-regeneration steps caused an important change on the crystal lattice, as compared to the fresh stones, sorbent reactivity was also changed.

  18. Hydromorphone Injection

    MedlinePlus

    ... the body, vomiting, diarrhea, or failure to gain weight.tell your doctor if you are breast-feeding.if you ... Hydromorphone injection may cause side effects. Tell your doctor if any of these ... vomiting constipation dry mouth lightheadedness dizziness drowsiness ...

  19. Spatial location of the space charge effect in individual ion clouds using monodisperse dried microparticulate injection with a twin quadrupole inductively coupled plasma mass spectrometer.

    PubMed

    Allen, L A; Leach, J J; Houk, R S

    1997-07-01

    Pulses of analyte and matrix ions from individual drops are measured simultaneously using a twin quadrupole inductively coupled plasma mass spectrometer (ICP-MS). The sample solution is introduced by monodisperse dried microparticulate injection (MDMI). At modest Pb concentrations (500 ppm), a shoulder on the leading edge of the Li(+) signal appears. At higher matrix concentrations (1000 to at least 1500 ppm), a dip in the leading edge of the Li(+) signal develops. These changes in the shapes of the Li(+) pulses are attributed to space charge effects in the extraction system and ion optics of the mass spectrometer. A qualitative depiction for this behavior is proposed, in which the Li(+) ions are deflected out of the preferred ion path and then refocused by the ion optics. Part of the Li(+) ion cloud is driven ahead of the Pb(+) cloud, and part is trapped behind the Pb(+) cloud. The result is a shoulder on the leading edge of the Li(+) signal. With the Pb matrix present, the shapes of the analyte ion pulses are sensitive to the voltages applied to the first two ion lenses, especially the extractor lens. This observation shows that the part of the matrix effect that occurs in the ion optics takes place mainly in the first two lenses.

  20. CO2 mitigation via accelerated limestone weathering

    USGS Publications Warehouse

    Rau, G.H.; Knauss, K.G.; Langer, W.H.; Caldeira, K.

    2004-01-01

    Accelerated weathering of limestone (AWL: CO22+ + CaCO3 + H2O ??? Ca2+ + 2HCO3- as a low-tech, inexpensive, high-capacity, environmentally-friendly CO2 capture and sequestration technology was evaluated. With access to seawater and limestone being essential to this approach, significant limestone resources were close to most CO2-emitting power plants along the coastal US. Waste fines, representing > 20% of current US crushed limestone production (> 109 tons/yr), could be used as an inexpensive source of AWL carbonate. AWL end-solution disposal in the ocean would significantly reduce effects on ocean pH and carbonate chemistry relative to those caused by direct atmospheric or ocean CO2 disposal. Indeed, the increase in ocean Ca2+ and bicarbonate offered by AWL should enhance growth of corals and other calcifying marine organisms.

  1. [Limestone and pyrite-limestone constructed wetlands for treating river water].

    PubMed

    Zhang, Jing; Li, Rui-hua; Li, Jie; Hu, Jun-song; Sun, Qian-qian

    2013-09-01

    Polluted river water was treated with limestone and pyrite-limestone subsurface horizontal constructed wetlands. The aims were to know the performance of two wetlands on removal of common pollutants, especially nitrogen and phosphorus, and analyze the actions of these minerals. The relationship between hydraulic retention time and purification performance of two constructed wetlands was studied. The optimal hydraulic retention time for pollutant removal was about 3 d, The average removal efficiency of COD, TN and TP were 51%, 70% and 95%, respectively. With same influent and hydraulic loading, the average removal efficiency of COD, NH4+ -N, TN and TP were 53.93%, 82.13%, 66%, 50.9%, and 51.66%, 77.43%, 72.06%, 97.35% for limestone and pyrite-limestone constructed wetlands, respectively. There were few differences between limestone and pyrite-limestone wetlands on COD removal, but the nitrogen and phosphorus removal of pyrite-limestone constructed wetland was higher than that of limestone constructed wetland. The phosphorus removal of pyrite-limestone wetland was more efficiency and stable, not affected by temperature.

  2. Inelastic compaction of a quartz-rich limestone (Invited)

    NASA Astrophysics Data System (ADS)

    Baud, P.; Schubnel, A.; rolland, A.; Heap, M. J.

    2013-12-01

    The analysis of deformation and failure in many sedimentary settings hinges upon a fundamental understanding of inelastic behavior and failure mode of porous carbonate rocks. Previous studies on porous carbonate focused primarily on relatively pure limestone (composed in majority of calcite). Inelastic compaction in these carbonates was reported to be associated to cataclastic pore collapse and in most cases homogeneous cataclastic flow. Recent experimental results however revealed the development of compaction localization in the more porous end-members. The analysis of strain localization and complex failure modes in limestone has proved to be significantly more challenging than in sandstone because acoustic emissions (AE) cannot usually be used to guide systematic microstructural analysis. Recent studies have therefore relied on X-ray Computed Tomography, a technique that can to date only be used in situ in relatively limited systems. In this study we investigated the development of inelastic damage in a quartz-rich limestone with two main objectives: (1) quantify the impact of a secondary mineral such as quartz on the strength and strain localization in porous carbonate, (2) try to follow the development of inelastic damage using AE in such a quartz-rich rock. Saint-Maximin limestone of 37% porosity and composed of 80% calcite and 20% quartz was selected for this study. Two series of conventional triaxial experiments were performed in parallel at room temperature, constant strain rate in both nominally dry and wet conditions at confining pressures between 3 and 50 MPa. Wet experiments were carried out with water in drained conditions at 10 MPa of pore pressure. The first series of experiments were performed at IPG Strasbourg on relatively small samples. The failure modes and spatial distribution of damage were studied systematically in these samples. The second series of experiments were performed on larger samples at ENS Paris. Acoustic emission activity was

  3. Recovery and recycling of limestone in LEC flue gas desulfurization. Final report, September 1, 1991--August 31, 1992

    SciTech Connect

    Gardner, N.C.; Boo, J.Y.; Culver, L.

    1992-09-01

    Prudich et. al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases on contact. Sulfite and sulfate salts deposit on the surface of the particles; however, the gas never reaches the interior, limiting the limestone utilization to approximately 20% or less. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economics are derived from small equipment, simplicity, and low sorbent costs. This project is a wet method for grinding and recovering the spent limestone from the LEC process, utilizing an impeller fluidizer, a new type of slurry processor. It consists of a cylindrical vessel with an impeller at one end. The impeller, driven at high rpm, concentrates the gravel size limestone in a rotating torus at the top of the cylinder, where the coating is abraded off by particle-particle impaction. The impeller generates sufficient pressure head to serve as a slurry pump. It combines the operation of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry. The fluidizer may be advantageous over dry grinding in the aspects of sharpness of separation, transport convenience, equipment erosion, and sorption bed cementation.

  4. Colour changes by laser irradiation of reddish building limestones

    NASA Astrophysics Data System (ADS)

    Grossi, C. M.; Benavente, D.

    2016-10-01

    We have used X-ray photoelectron spectroscopy (XPS) as a novel method to investigate the causes of colour changes in a reddish limestone under irradiation by a Q-switched Nd:YAG 1064 nm laser. We irradiated clean dry and wet surfaces of Pidramuelle Roja, a building stone frequently used in the Asturian heritage, at fluences ranging from 0.12 to 1.47 J cm-2. We measured the colour coordinates and undertook XPS analysis of the state of oxidation of iron both before and after irradiation. Visible colour changes and potential aesthetic damage occurred on dry surfaces from a fluence of 0.31 J cm-2, with the stone showing a greening effect and very intense darkening. The colour change on dry surfaces was considerably higher than on wet surfaces, which at the highest fluence (1.47 J cm-2) was also above the human visual detection threshold. The use of XPS demonstrated that the change in colour (chroma and hue) is associated with a reduction in the iron oxidation state on dry surfaces during laser irradiation. This points out to a potential routinary use of XPS to analyse causes of colour changes during laser cleaning in other types of coloured building stones.

  5. Forest seasonality shapes diet of limestone-living rhesus macaques at Nonggang, China.

    PubMed

    Tang, Chuangbin; Huang, Libin; Huang, Zhonghao; Krzton, Ali; Lu, Changhu; Zhou, Qihai

    2016-01-01

    Limestone forests are an unusual habitat for primates, but little information is available for the genus Macaca in such habitats, making a comparative understanding of extant limestone primates' behavioral adaptation incomplete. We collected data on the diet of rhesus macaques (Macaca mulatta) in a limestone habitat at Nonggang Nature Reserve, southwestern Guangxi, China, and examined the effects of forest seasonality on their diet. Our results indicated that a total of 114 species of plants are consumed by macaques. Young leaves are a preferred food, accounting for 48.9 and 56.9% of the overall diets. One group significantly increased young leaf consumption in response to availability. Fruits contributed to only 27.3 and 28.7% of overall diet. The macaque diet varied according to season. They fed on more fruits in the rainy season. Consumption of mature leaves increased when the availability of young leaves and fruits declined in the dry season, indicating that mature leaves are a fallback food for macaques in a limestone habitat. Similar to sympatric Assamese macaques, Bonia saxatilis, a shrubby, karst-endemic bamboo was consumed by rhesus macaques throughout the year, and was the top food species through most of the year, suggesting that bamboo consumption represents a key factor in the macaque's dietary adaptation to limestone habitat.

  6. Influence of clay swelling on the mechanical behaviour of Egyptian Helwan limestone

    NASA Astrophysics Data System (ADS)

    Aly, Nevin

    2016-04-01

    Clay minerals exist naturally in the majority of different Egyptian limestones types. Changes in the dimensions of clays during swelling / shrinking process induced by changes in the environmental conditions can result in acceleration the deterioration of the hosting stone. Petrographic investigation by scanning - electron microscope (SEM) of Helwan limestone (biomicritic limestone) revealed distribution of a typical smectite morphology (curled - leaf shape) beside abundance of glauconite pellets within the stone material. The clay frication extracted from Helwan reached 10% and oriented aggregates samples were analyzed by X- ray diffraction (XRD) and confirmed the identification of smectite as the main mineral in the clay frication. To study the effect of the clay content on the mechanical behavior of Helwan limestone, hygric swelling test was performed at first by using displacement sensor and then the effect of multiple wetting/ drying cycles on the stone strength was determined using unconfined compressive strength (UCS). Results revealed that there was a significant correlation between degree of swelling of the clay and strength of the limestone.

  7. Forest seasonality shapes diet of limestone-living rhesus macaques at Nonggang, China.

    PubMed

    Tang, Chuangbin; Huang, Libin; Huang, Zhonghao; Krzton, Ali; Lu, Changhu; Zhou, Qihai

    2016-01-01

    Limestone forests are an unusual habitat for primates, but little information is available for the genus Macaca in such habitats, making a comparative understanding of extant limestone primates' behavioral adaptation incomplete. We collected data on the diet of rhesus macaques (Macaca mulatta) in a limestone habitat at Nonggang Nature Reserve, southwestern Guangxi, China, and examined the effects of forest seasonality on their diet. Our results indicated that a total of 114 species of plants are consumed by macaques. Young leaves are a preferred food, accounting for 48.9 and 56.9% of the overall diets. One group significantly increased young leaf consumption in response to availability. Fruits contributed to only 27.3 and 28.7% of overall diet. The macaque diet varied according to season. They fed on more fruits in the rainy season. Consumption of mature leaves increased when the availability of young leaves and fruits declined in the dry season, indicating that mature leaves are a fallback food for macaques in a limestone habitat. Similar to sympatric Assamese macaques, Bonia saxatilis, a shrubby, karst-endemic bamboo was consumed by rhesus macaques throughout the year, and was the top food species through most of the year, suggesting that bamboo consumption represents a key factor in the macaque's dietary adaptation to limestone habitat. PMID:26530218

  8. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 6, January--March 1992

    SciTech Connect

    Not Available

    1992-09-01

    The LIFAC technology has similarities to other sorbent injection technologies using humidification, but employs a unique patented vertical reaction chamber located down-stream of the boiler to facilitate and control the sulfur capture and other chemical reactions. This chamber improves the overall reaction efficiency enough to allow the use of pulverized limestone rather than more expensive reagents such as lime which are often used to increase the efficiency of other sorbent injection processes. Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers - and requires more reagent material. However, if the demonstration is successful, LIFAC will offer these important advantages over wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems; LIFAC is less expensive to install than conventional wet FGD processes; LIFAC`s overall costs measured on a dollar-per-ton S0{sub 2} removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product; and LIFAC is relatively simple to operate.

  9. Effect of Limestone Fillers the Physic-Mechanical Properties of Limestone Concrete

    NASA Astrophysics Data System (ADS)

    bederina, Madani; makhloufi, Zoubir; bouziani, Tayeb

    This work focuses on the exploitation of local industrial wastes and their use in the formulation of new concretes which can be used in local constructions. The valorised materials are limestone crushing sand (0/5 mm) and limestone fillers (80 μm). The two materials are extracted from local aggregate crushing wastes. Thus, and since the used gravels are also of limestone nature, the formulated composite is a limestone concrete. So this study constitutes an experimental work that aims at the study of the effect of the addition of limestone fillers on the physico-mechanical behaviour of limestone concrete. To carry out this study, different proportions of fillers ranging from 0 to 40% were considered. Very important results have been achieved on the workability and strength. By increasing the amount of limestone filler in concrete, the first one improves, but the second one increases then decreases passing by an optimal content of fillers which gives a maximum mechanical strength. Finally, and concerning the dimensional variations, it is noteworthy that they decrease at the beginning till an optimal value of fillers content, but beyond this optimum, they start increasing without exceeding recommended values.

  10. Comparison between intralesional injection of zinc sulfate 2 % solution and intralesional meglumine antimoniate in the treatment of acute old world dry type cutaneous leishmaniasis: a randomized double-blind clinical trial.

    PubMed

    Farajzadeh, Saeedeh; Hakimi Parizi, Maryam; Haghdoost, Ali Akbar; Mohebbi, Azadeh; Mohammadi, Saman; Pardakhty, Abbas; Eybpoosh, Sana; Heshmatkhah, Amireh; Vares, Behrooz; Saryazdi, Simin; Fekri, Ali Reza; Mohebbi, Elham

    2016-09-01

    Zinc sulfate (ZS) has been used for the treatment of acute cutaneous leishmaniasis (CL) in both forms of in vivo and in vitro recently. The aim of the present study was to compare the efficacy of intralesional injection of ZS 2 % solution with intralesional glucantime in the treatment of acute CL. In this double-blind randomized clinical trial, 80 cases with acute old world dry type CL were enrolled in the study. The treatment protocol in the first group consisted of intralesional injection of ZS 2 % vials once a week for 10 weeks or sooner in case of complete resolution of the lesions. In the second group, intralesional glucantime once a week for 10 weeks or sooner in case of complete resolution of the lesions were used. In both groups cryotherapy was performed once every other week for 10 weeks. In ZS versus second group, partial and complete clinical response was observed with fewer injections although this difference was not statistically significant. In addition, we found that the trend of treatment in second group was faster but again it was not significant [partial treatment: hazard ratio (HR) 1.4, 95 % CI 0.7-2.9; complete treatment: HR 1.3, 95 % CI 0.6-2.8]. The results of this study showed that the intralesional injection of ZS 2 % solution was as effective as glucantime on the healing of the acute old world dry type CL. PMID:27605813

  11. Fluid distribution effect on sonic attenuation in partially saturated limestones

    SciTech Connect

    Cadoret, T.; Mavko, G.; Zinszner, B.

    1998-01-01

    Extensional and torsional wave-attenuation measurements are obtained at a sonic frequency around 1 kHz on partially saturated limestones using large resonant bars, 1 m long. To study the influence of the fluid distribution, the authors use two different saturation methods: drying and depressurization. When water saturation (S{sub w}) is higher than 70%, the extensional wave attenuation is found to depend on whether the resonant bar is jacketed. This can be interpreted as the Biot-Gardner-White effect. The experimental results obtained on jacketed samples show that, during a drying experiment, extensional wave attenuation is influenced strongly by the fluid content when S{sub w} is between approximately 70% and 100%. This sensitivity to fluid saturation vanishes when saturation is obtained through depressurization. Using a computer-assisted tomographic (CT) scan, the authors found that, during depressurization, the fluid distribution is homogeneous at the millimetric scale at all saturations. In contrast, during drying, heterogeneous saturation was observed at high water-saturation levels. Thus, the authors interpret the dependence of the extensional wave attenuation upon the saturation method as principally caused by a fluid distribution effect. Torsional attenuation shows no sensitivity to fluid saturation for S{sub w} between 5% and 100%.

  12. Acidic stream mitigation by limestone sand addition

    SciTech Connect

    Brant, D.L.; Marich, A.J. Jr.; Largent, K.L.

    1996-12-31

    The Town Line Run watershed comprises an area of 3,600 wooded acres. The tributaries feeding the stream consist of sandstone springs that do not contribute alkalinity to the watershed, leaving the stream susceptible to acid precipitation. This has a negative affect on Iser`s Run, a native brook trout fishery above the confluence with Town Line Run. The objective in stream liming is to improve water chemistry by increasing pH, alkalinity, and reducing acidity, aluminum, and iron. Introducing crushed limestone directly into a stream from a dump truck is an inexpensive but temporary solution to accomplish this objective. In this type of liming operation, a bed of limestone is spread down the stream channel by the momentum of the stream from the introduction point, rather than manually. Water moving across this bed dissolves the limestone, increasing the pH, alkalinity, and calcium while decreasing the acidity, iron, and aluminum concentrations of the water. The size of the limestone particles is important for this purpose because particles that are too small (<150 microns) will carried away, while particles that are too large (>1000 microns) will remain at the introduction point. Our study placed 80 tons of sand-sized limestone (85% calcite) in the stream channel at a single point. Water samples were collected monthly at the following sites (1) directly upstream of the addition site, (2) 100 yards downstream of the site, and (3) 2500 yards downstream of the site. Other sample locations include (4) upstream and (5) downstream of the Town Line Run- Iser`s Run confluence and the Casselman River upstream (6) and downstream (7) of Town Line Run. The samples were analyzed for pH. Specific conductivity, Alkalinity, Acidity, Iron, Manganese, Aluminum, and Sulfate.

  13. Dry Mouth

    MedlinePlus

    ... of this page please turn Javascript on. Dry Mouth What Is Dry Mouth? Dry mouth is the feeling that there is ... when a person has dry mouth. How Dry Mouth Feels Dry mouth can be uncomfortable. Some people ...

  14. Mineralogical characterization of the Shelburne marble and the Salem limestone

    SciTech Connect

    McGee, E.S.

    1989-01-01

    Samples of Shelburne marble and Salem limestone were selected to represent marbles and limestones used in buildings and monuments. The Royal variety of Shelburne marble is a white marble predominantly composed of calcite but has heterogeneously distributed gray inclusions. The select buff Salem limestone is a beige, homogeneous, fossiliferous limestone, predominantly composed of fragments of echinoderms and bryozoans. The author reports that both samples are appropriate test stones for the National Acid Precipitation Assessment Program stone exposure studies.

  15. Limestone treatment for sulfur dioxide removal. (Latest citations from the EI compendex*plus database). Published Search

    SciTech Connect

    1998-02-01

    The bibliography contains citations concerning the use of limestone for the control of sulfur dioxide emmisions in flue gases. The various designs for flue gas desulfurization are discussed, including dry fluidized beds and wet scrubbers. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Physicochemical characterizations of limestone for fluidized-bed coal combustion

    SciTech Connect

    Fuller, E.L. Jr.; Yoos, T.R. III; Walia, D.S.

    1981-05-01

    This study is an investigation of the physicochemical characteristics of three limestone samples, Quincy limestone (-20 + 60), Franklin limestone (-12 + 30), and Franklin limestone (-6 + 16), currently being tested at Oak Ridge National Laboratory for use in a fluidized-bed coal combustion unit. By correlating the chemistry, mineralogy, and surface area of these samples with empirical data obtained at Argonne National Laboratory, the sulfur capture ability and performance of these limestones can be loosely predicted. X-ray fluorescence and neutron activation analysis revealed a very high calcium content and very low concentrations of other elements in the three samples. X-ray diffraction patterns and petrographic examination of the limestone grains detected essentially no dolomite in the Quincy limestone or the fine Franklin limestone samples. The coarse Franklin limestone sample showed dolomite to be present in varying amounts up to maximum of 2.75%. Limited surface chemistry investigations of the samples were undertaken. Limestone and dolostone resources of the Tennessee Valley Authority region are widespread and abundant, and judged sufficient to meet industrial demand for many years. No problems are anticipated in securing limestone or dolostone supplies for a commercial fluidized-bed combustion plant in the Tennessee Valley Authority region. Transportation facilities and costs for limestone or dolostone will influence the siting of such a commercial fluidized-bed combustion plant. The most promising location in the Tennessee Valley Authority region at this time is Paducah, Kentucky.

  17. Limestone reaction in calcium aluminate cement–calcium sulfate systems

    SciTech Connect

    Bizzozero, Julien Scrivener, Karen L.

    2015-10-15

    This paper reports a study of ternary blends composed of calcium aluminate cement, calcium sulfate hemihydrate and limestone. Compressive strength tests and hydration kinetics were studied as a function of limestone and calcium sulfate content. The phase evolution and the total porosity were followed and compared to thermodynamic simulation to understand the reactions involved and the effect of limestone on these binders. The reaction of limestone leads to the formation of hemicarboaluminate and monocarboaluminate. Increasing the ratio between sulfate and aluminate decreases the extent of limestone reaction.

  18. Integrated dry NO{sub x}/SO{sub 2} emissions control systems: Advanced retractable injection lance SNCR test report. NOELL ARIL test period: April 20, 1995--December 21, 1995; DPSC test period: August 16--26, 1996

    SciTech Connect

    Muzio, L.J.; Smith, R.A.; Hunt, T.

    1997-04-01

    The test site is Arapahoe Generating Station Unit 4, a 100 MWe down-fired utility boiler burning a low-sulfur western coal. The project goal is to demonstrate up to 70% reductions in NOx and SO{sub 2} emission through the integration of: (1) down-fired low-NOx burners with overfire air; (2) Selective Non-Catalytic Reduction (SNCR) for additional NOx removal; and (3) dry sorbent injection and duct humidification for SO{sub 2} removal. This report documents the third phase of SNCR tests, where an additional injection location was installed to increase the low-load NOx removal performance. The new injectors consist of a pair of retractable in-furnace lances which were designed to provide a high degree of load following flexibility through on-line adjustments of the injection angle. With the new lances, NOx removals in excess of 35% are achievable at the same load and HN{sub 3} slip limit. At loads of 43 to 60 MWe, NOx removals with the lances range from 37--52%. At loads greater than 60 MWe, the wall-injection location is more efficient, and at loads of 70 to 100 MWe, NOx removals range from 37--41%. The coal mill-in-service pattern was found to have a large effect on both NOx removal and NH{sub 3} slip for injection at the new lance location. At 60 MWe, the NOx removal at the 10 ppm NH{sub 3} slip limit ranges from 28--52% depending on the mill-in-service pattern. Biasing the coal mills to provide uniform combustion conditions ahead of the injection location was found to be the best option for improving SNCR system performance under these conditions.

  19. Limestone quarrying and quarry reclamation in Britain

    NASA Astrophysics Data System (ADS)

    Gunn, J.; Bailey, D.

    1993-06-01

    Limestones have been worked for many thousands of years — initially for building stone and agricultural lime and more recently for a wide range of construction and industrial uses. In most industrialized countries limestone quarries represent the most visually obvious and, in both process and landform terms, the most dramatic anthropogenic impact on karst terrain. However, quarrying has, to date, received surprisingly little attention from karst scientists. Research in the English Peak District suggested that the postexcavation evolution of quarried limestone rock faces was in part a result of the methods used in their excavation, and this led to the development of a technique designed to reduce the visual and environmental impacts of modern quarries by “Landform replication. ” This involves the use of controlled “restoration blasting” techniques on quarried rock slopes to construct a landform sequence similar to that in the surrounding natural landscape. The constructed landforms are then partially revegetated using appropriate wildflower, grass, and/or tree species.

  20. Simulation of Hypervelocity Penetration in Limestone

    SciTech Connect

    Antoun, T; Glenn, L; Walton, O; Goldstein, P; Lomov, I; Liu, B

    2005-05-31

    A parameter study was performed to examine the (shock) damage obtained with long-rod and spherical mono-material penetrators impacting two varieties of limestone. In all cases, the impacts were assumed to be normal to the plane of the rock and at zero angle of attack (in the case of the rods). Impact velocities ranged to 15 km/s but most calculations were performed at 4 and 6 km/s and the penetrator mass was fixed at 1000 kg. For unlined underground structures, incipient damage was defined to occur when the peak stress, {sigma}{sub pk}, exceeds 1 kb (100 MPa) and the applied impulse per unit area, I{sub pk}, exceeds 1 ktap (1 kb-{micro}s). Severe damage was assumed to occur when {sigma}{sub pk} exceeds 1 kb and I{sub pk} exceeds 1000 ktaps. Using the latter definition it was found that severe damage in hard, non-porous limestone with spherical impactors extended to a depth of 9 m on-axis for an impact velocity of 4 km/s and 12 m at 6 km/s. Cylinders with length-to-diameter (L/D) ratio of 8.75 achieved depth to severe damage of 23 m and 40 m, respectively under the same conditions. For a limestone medium with 2% initial gas porosity, the latter numbers were reduced to 12 m and 18 m.

  1. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 9, October--December 1992

    SciTech Connect

    Not Available

    1992-12-31

    Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers -- and requires more reagent material. However, if the demonstration is wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems. LIFAC is less expensive to install than conventional wet FGD processes. LIFAC`s overall costs measured on a dollar-per-ton SO{sub 2} removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product. LIFAC is relatively simple to operate.

  2. CO2 MITIGATION VIA ACCELERATED LIMESTONE WEATHERING

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K G

    2004-02-27

    The climate and environmental impacts of our current, carbon-intensive energy usage demands that effective and practical energy alternatives and CO2 mitigation strategies be found. As part of this effort, various means of capturing and storing CO2 generated from fossil-fuel-based energy production are being investigated. One of the proposed methods involves a geochemistry-based capture and sequestration process that hydrates point-source, waste CO2 with water to produce a carbonic acid solution. This in turn is reacted and neutralized with limestone, thus converting the original CO2 gas to calcium bicarbonate in solution, the overall reaction being:

  3. The Helderberg limestone of central Pennsylvania

    USGS Publications Warehouse

    Reeside, John B.

    1917-01-01

    This paper presents the results of a study made during 1913, 1914, and 1915, while the writer was a student at Johns Hopkins University. The formations discussed have been studies in Maryland, New Jersey, and New York, and described with more or less detail, but concerning their occurrence in the intervening area in Pennsylvania little exact information has been available. The conflict in opinion as to the proper position and correlation of the Keyser limestone and as to the interpretation of some of the standard New York sections has made further data very desirable, and the present paper is an attempt to meet a part of the deficiency.

  4. Introduction to limestone flue gas desulfurization: Videotape workbook

    SciTech Connect

    Not Available

    1988-01-01

    The workbook is designed to accompany the Electric Power Research Institute's (EPRI's) videotape, ''Introduction to Limestone Flue Gas Desulfurization.'' To complement the videotape, the workbook provides additional information on limestone flue gas desulfurization (FGD) and a guide to sources of still more information. The videotape itself presents an introduction to the chemistry involved in a limestone FGD system. Following a description of a typical system, the basic chemical reactions that occur in this process are detailed. The most common operation problems in limestone FGD---low sulfur dioxide removal, low limestone utilization, and scaling---are reviewed with regard to how process chemistry can be controlled to alleviate these problems. This tape is an introduction only; future tapes will cover limestone FGD performance indicators and troubleshooting in more detail.

  5. Dynamic properties of Indiana, Fort Knox and Utah test range limestones and Danby Marble over the stress range 1 to 20 GPa

    SciTech Connect

    Furnish, M.D.

    1994-12-01

    The responses of the following carbonate materials to shock loading and release have been measured: Indiana limestone (18% porosity; saturated and dry), Jeffersonville/Louisville Limestones (Fort Knox limestone) (variable dolomitization, low porosity), Danby Marble (essentially pure calcite; low porosity), and a limestone from the Utah Test and Training Range (low porosity, with 22% silica). Various experimental configurations were used, some optimized to yield detailed waveform information, others to yield a clean combination of Hugoniot states and release paths. All made use of velocity interferometry as a primary diagnostic. The stress range of 0 - 20 GPa was probed (in most cases, emphasizing the stress range 0 -10 GPa). The primary physical processes observed in this stress regime were material strength, porosity, and polymorphic phase transitions between the CaCO{sub 3} phases I, II, III and VI. Hydration was also a significant reaction under certain conditions. The Indiana Limestone studies in particular represent a significant addition to the low-pressure database for porous limestone. Temperature dependence and the effect of freezing were assessed for the Fort Knox limestone. Experimental parameters and detailed results are provided for the 42 impact tests in this series.

  6. Limestone types used from the classic Karst region in Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Bedjanič, Mojca; Kortnik, Jože; Šmuc, Andrej

    2014-05-01

    The paper presents a variety of limestones from the Karst Region that is one of the most interesting areas containing reserves of natural stones in Slovenia. The region is mainly composed of Cretaceous shallow-water limestone, with the most common type currently excavated being the rudist limestone of the Lipica Formation, which dates to the Santonian to Campanian. Limestones of this formation are mainly represented by a light grey, thick-bedded to massive Lipica limestone rich in (largely fragmented) rudists. Rudist shells can be either relatively well preserved (such as in Lipica Fiorito quarried limestone) or almost completely disintegrated and intensively endolitised (Lipica Unito quarried limestone). Beside the Lipica Formation, natural stone types have been excavated from two other formations or members in the Karst region: the Repen Formation (Repen and Kopriva limestones), and the Tomaj Limestone (dark, laminated limestone within the Lipica Formation). As documented, the region has been associated with the quarrying and processing of stone at least for over two thousand years, i.e. since the Roman period. Although a large number of quarries in all mentioned formations are documented in the Karst region, many are inactive nowadays. Some of the quarries are declared as geological monuments of national importance or officially protected as a natural monument. Karst limestones are considered the highest quality calcareous natural stones in Slovenia. They are characterised by high density, low water absorption and low open porosity; consequently they also exhibit high frost and salt resistance as well as high compressive and flexural strength. Besides in the Karst region and other parts of Slovenia, the Karst limestones were used in the construction of several important buildings and monuments in many other European Countries, and worldwide. Nowadays, they are most commonly used in the construction of façade cladding, pavements, window sills, staircases, indoor

  7. [Effects of variable temperature on organic carbon mineralization in typical limestone soils].

    PubMed

    Wang, Lian-Ge; Gao, Yan-Hong; Ding, Chang-Huan; Ci, En; Xie, De-Ti

    2014-11-01

    Soil sampling in the field and incubation experiment in the laboratory were conducted to investigate the responses of soil organic carbon (SOC) mineralization to variable temperature regimes in the topsoil of limestone soils from forest land and dry land. Two incubated limestone soils were sampled from the 0-10 cm layers of typical forest land and dry land respectively, which were distributed in Tianlong Mountain area of Puding county, Guizhou province. The soils were incubated for 56 d under two different temperature regimes including variable temperature (range: 15-25 degrees C, interval: 12 h) and constant temperature (20 degrees C), and the cumulative temperature was the same in the two temperature treatments. In the entire incubation period (56 d), the SOC cumulative mineralization (63.32 mg x kg(-1)) in the limestone soil from dry land (SH) under the variable temperature was lower than that (63.96 mg x kg(-1)) at constant 20 degrees C, and there was no significant difference in the SOC cumulative mineralization between the variable and constant temperature treatments (P < 0.05). While the cumulative mineralization (169.46 mg x kg(-1)) of organic carbon in the limestone soil from forest land (SL) under the variable temperature was significantly lower than that (209.52 mg x kg(-1)) at constant 20 degrees C. The results indicated that the responses of SOC mineralization to the variable temperature were obviously different between SL and SH soils. The SOC content and composition were significantly different between SL and SH soils affected by vegetation and land use type, which suggested that SOC content and composition were important factors causing the different responses of SOC mineralization to variable temperature between SL and SH soils. In addition, the dissolved organic carbon (DOC) content of two limestone soils were highly (P < 0.01) positively correlated with daily mineralization of soil organic carbon in both temperature treatments, which implied that

  8. The influence of spray-drying parameters on phase behavior, drug distribution, and in vitro release of injectable microspheres for sustained release.

    PubMed

    Meeus, Joke; Lenaerts, Maité; Scurr, David J; Amssoms, Katie; Davies, Martyn C; Roberts, Clive J; Van Den Mooter, Guy

    2015-04-01

    For ternary solid dispersions, it is indispensable to characterize their structure, phase behavior, and the spatial distribution of the dispersed drug as this might influence the release profile and/or stability of these formulations. This study shows how formulation (feed concentration) and process (feed rate, inlet air temperature, and atomizing air pressure) parameters can influence the characteristics of ternary spray-dried solid dispersions. The microspheres considered here consist of a poly(lactic-co-glycolic acid) (PLGA) surface layer and an underlying polyvinylpyrrolidone (PVP) phase. A poorly soluble active pharmaceutical ingredient (API) was molecularly dispersed in this matrix. Differences were observed in component miscibility, phase heterogeneity, particle size, morphology, as well as API surface coverage for selected spray-drying parameters. Observed differences are likely because of changes in the droplet generation, evaporation, and thus particle formation processes. However, varying particle characteristics did not influence the drug release of the formulations studied, indicating the robustness of this approach to produce particles of consistent drug release characteristics. This is likely because of the fact that the release is dominated by diffusion from the PVP layer through pores in the PLGA surface layer and that observed differences in the latter have no influence on the release.

  9. The Surface of a Limestone-Rich World?

    NASA Astrophysics Data System (ADS)

    Melis, Carl; Dufour, Patrick

    2016-06-01

    We present spectroscopic observations of the dust- and gas-enshrouded, polluted white dwarf star SDSSJ104341.53+085558.2 (hereafter SDSSJ1043). Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet spectra combined with deep Keck HIRES optical spectroscopy reveal the elements C, O, Mg, Al, Si, P, S, Ca, Fe, and Ni and enable useful limits for Sc, Ti, V, Cr, and Mn in the photosphere of SDSSJ1043. From this suite of elements we determine that the parent body being accreted by SDSSJ1043 is dry, rocky, and iron-poor. Synthesizing all available heavily-polluted white dwarf measurements, we find a trend in the Fe/Mg vs Fe/Si abundance ratio-space suggestive of whether accreted material originates from the inner or outer regions of a rocky body; we use this trend to identify the material being accreted by SDSSJ1043 as likely to have come from the outermost layers of a differentiated object. Enhanced levels of Ca and C in this object can be explained by the presence of significant amounts of calcium-carbonate and, if definitive, could be suggestive of a world with a crust rich in limestone.

  10. Local facies variability in the Mission Canyon Limestone, west flank, Bighorn Mountains, Wyoming

    SciTech Connect

    Vice, M.A.; Utgaard, J.E. )

    1991-06-01

    Comparison of two sections of the Mission Canyon Limestone (Madison Group, Mississippian) located approximately one-half mile (850-900 m) apart and at opposite ends of a single flatiron reveals significant lateral facies variations. The southern section, Dry Fork of Horse Creek, is 83 ft (25 m) thicker than the northern Horse Creek section. This substantial difference in thickness cannot be attributed solely to pre-Amsden erosion and solution collapse: all three members are thicker and more variable lithologically at Dry Fork. The lower (Big Goose) member is composed mostly of cherty, dolomitized lime mudstones at both locations. At Dry Fork, it contains numerous skeletal facies, particularly in the upper part. Skeletal facies are insignificant at Horse Creek. The two upper members are composed mainly of skeletal limestones; however, grain-supported facies are much more abundant at Dry Fork. Dolomitized mudstones predominate in the major breccia at the base of the middle (Little Tongue) member at Horse Creek, and lime mudstones predominate at Dry Fork. Additional breccias occur at other horizons: five at Dry Fork, four at Horse Creek. Conclusions drawn from the initial study of these two outcrops follow: (1) the local extent of grainstones and packstones suggests that the shoals were geographically less extensive than the subtidal muddy bottoms and intertidal-supratidal mud flats. (2) The limited geographic and vertical extent of some breccias suggests evaporiate deposition in localized muddy facies. (3) Conditions favoring dolomitization were limited mainly to the mudstones and occurred during and shortly after deposition of the Big Goose Member.

  11. [Analysis of trace elements in limestone for archeological functions

    SciTech Connect

    Blanc, A.; Holmes, L.; Harbottle, G.

    1998-12-31

    Numerous quarries in the Lutetian limestone formations of the Paris Basin provided stone for the building and the decoration of monuments from antiquity to the present. To determine the origin of stone used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 samples. Petrographic and paleontologic examination of thin sections allows geologists to distinguish Lutetian limestones from Jurassic and Cretaceous limestones. Geologists also seek to formulate hypotheses regarding the origin of Lutetian limestones used for building and sculpture in the Paris region. In the search for the sources of building and sculptural stone, the analytical methods of geologists are limited because often several quarries produce the same lithofacies. A new tool is now available, however, to attack questions of provenance raised by art historians. Because limestones from different sources have distinctive patterns of trace-element concentrations, compositional analysis by neutron activation allows one to compare building or sculptural stone from one monument with stone from quarries or other monuments. This analytical method subjects a powdered limestone sample to standard neutron activation analysis procedures at Brookhaven National Laboratory. With the help of computer programs, the compositional fingerprints of Lutetian limestones can be determined and stored in a database. The limestone database contains data for approximately 2,100 samples from monuments, sculptures and quarries. It is particularly rich in samples from the Paris Basin.

  12. Microfacies and diagenesis of the reefal limestone, Callovian Tuwaiq Mountain Limestone Formation, central Saudi Arabia

    NASA Astrophysics Data System (ADS)

    EL-Sorogy, Abdelbaset S.; Almadani, Sattam A.; Al-Dabbagh, Mohammad E.

    2016-03-01

    In order to document the microfacies and diagenesis of the reefal limestone in the uppermost part of the Callovian Tuwaiq Mountain Limestone Formation at Khashm Al-Qaddiyah area, central Saudi Arabia, scleractinian corals and rock samples were collected and thin sections were prepared. Coral framestone, coral floatstone, pelloidal packstone, bioclastic packstone, bioclastic wacke/packstone, algal wackestone and bioclastic foraminiferal wacke/packstone were the recorded microfacies types. Cementation, recrystallization, silicification and dolomitization are the main diagenetic alterations affected the aragonitic skeletons of scleractinian corals. All coral skeletons were recrystallized, while some ones were dolomitized and silicified. Microfacies types, as well as the fossil content of sclearctinian corals, bivalves, gastropods, brachiopods and foraminifera indicated a deposition in environments ranging from shelf lagoon with open circulation in quiet water below wave base to shallow reef flank and organic build up for the uppermost reefal part of the Tuwaiq Formation in the study area.

  13. Thermo-Hydro-Mechanical-Chemical Coupled Modeling of Geothermal Doublet Systems in Limestones

    NASA Astrophysics Data System (ADS)

    Rühaak, Wolfram; Pei, Liang; Heldmann, Claus-Dieter; Bartels, Jörn; Sass, Ingo

    2015-04-01

    Limestone aquifers in Southern Germany have been used within the last decade very successfully for geothermal heating and - to a lesser extent - for power generation. As an example the region around Munich has been extensively explored. While the extent of usage of this reservoir is increasing there is also an increased interest in better understanding of the reservoir properties and its change in the course of operation. For instance, the observed production and injection pressures are partly hard to explain. They may be related to mechanical or chemical processes, or both. Based on extensive data of outcrop studies and drillings, a data-base for the relevant physical properties of the respective limestones has been complied. The data include thermal conductivity, density, specific heat capacity, permeability, as well as mechanical properties like thermal expansion coefficient and elasticity modules. By using the hydro-thermo-chemical simulator FEFLOW together with an extension for thermo- and hydro-mechanical coupling the relevant processes are studied and compared with observed data. Conclusions for an optimized operation of geothermal systems in limestones are given and discussed.

  14. Field trial of a pulsed limestone diversion well

    USGS Publications Warehouse

    Sibrell, Philip L.; Denholm, C.; Dunn, Margaret

    2013-01-01

    The use of limestone diversion wells to treat acid mine drainage (AMD) is well-known, but in many cases, acid neutralization is not as complete as would be desired. Reasons for this include channeling of the water through the limestone bed, and the slow reaction rate of the limestone gravel. A new approach to improve the performance of the diversion well was tested in the field at the Jennings Environmental Education Center, near Slippery Rock, PA. In this approach, a finer size distribution of limestone was used so as to allow fluidization of the limestone bed, thus eliminating channeling and increasing particle surface area for faster reaction rates. Also, water flow was regulated through the use of a dosing siphon, so that consistent fluidization of the limestone sand could be achieved. Testing began late in the summer of 2010, and continued through November of 2011. Initial system performance during the 2010 field season was good, with the production of net alkaline water, but hydraulic problems involving air release and limestone sand retention were observed. In the summer of 2011, a finer size of limestone sand was procured for use in the system. This material fluidized more readily, but acid neutralization tapered off after several days. Subsequent observations indicated that the hydraulics of the system was compromised by the formation of iron oxides in the pipe leading to the limestone bed, which affected water distribution and flow through the bed. Although results from the field trial were mixed, it is believed that without the formation of iron oxides and plugging of the pipe, better acid neutralization and treatment would have occurred. Further tests are being considered using a different hydraulic configuration for the limestone sand fluidized bed.

  15. Faunas of Mississippian oolitic limestones: Evidence from Salem Limestone, southern Indiana

    SciTech Connect

    Feldman, H.R. )

    1989-08-01

    In the Salem Limestone of southern Indiana, a correlation exists between the faunal assemblage and abundance of grains with superficial oolitic coatings in grainstones. Coarse, poorly sorted fossiliferous grainstones are dominated by an echinoderm-bryozoan-brachiopod assemblage of fossils with few mollusks. The presence of large whole fossils, such as articulated crinoid calyces, suggest limited transport of skeletal components. Grainstones, dominated by grains with superficial coatings, and foraminifers tend to contain a diverse mollusk-dominated assemblage of gastropods, bivalves, rostroconchs, chitins, and scaphopods. These fossils are disarticulated, but generally are not fragmented even though many of them are thin and delicate. Echinoderms, brachiopods, and bryozoans are repsented in the mollusk-domdinated assemblage almost exclusively by well-rounded and coated fragments, suggesting that they are not in situ. The presence of similar molluscan assemblages in other Mississippian coated-grain grainstones from Alabama (the Monteagle Limestone) and Oklahoma (an unnamed limestone) indicates that the assemblage may have been wide-spread. Mississippian grainstones dominated by oolites (which are not prominent in the Salem) generally have very few fossils.

  16. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2000-12-01

    A test program is being sponsored by the US Department of Energy (DOE), EPRI, FirstEnergy, and TVA to investigate furnace injection of alkaline sorbents as a means of reducing sulfuric acid concentrations in the flue gas from coal-fired boilers. This test program is being conducted at the FirstEnergy Bruce Mansfield Plant (BMP), although later testing will be conducted at a TVA plant. A sorbent injection test was conducted the week of April 18, 2000. The test was the first of several short-term (one- to two-week duration) tests to investigate the effectiveness of various alkaline sorbents for sulfuric acid control and the effects of these sorbents on boiler equipment performance. This first short-term test investigated the effect of injecting dry dolomite powder (CaCO{sub 3} {center_dot} MgCO{sub 3}), a mineral similar to limestone, into the furnace of Unit 2. During the test program, various analytical techniques were used to assess the effects of sorbent injection. These primarily included sampling with the controlled condensation system (CCS) for determining flue gas SO{sub 3} content and an acid dew-point (ADP) meter for determining the sulfuric acid dew point (and, indirectly, the concentration of sulfuric acid) of the flue gas. EPA Reference Method 26a was used for determining hydrochloric acid (HCl) and hydrofluoric acid (HF), as well and chlorine (Cl{sub 2}) and fluorine (F{sub 2}) concentrations in the flue gas. Fly ash resistivity was measured using a Southern Research Institute (SRI) point-to-plane resistivity probe, and unburned carbon in fly ash was determined by loss on ignition (LOI). Coal samples were also collected and analyzed for a variety of parameters. Finally, visual observations were made of boiler furnace and convective pass surfaces prior to and during sorbent injection.

  17. Porosity and Permeability Evolution in Cemented Rock Cores under Reactive Flowing Conditions: Comparative Analysis between Limestone and Sandstone Host Rocks

    NASA Astrophysics Data System (ADS)

    Cao, P.; Karpyn, Z.; Li, L.

    2013-12-01

    CO2-brine has the potential to alter wellbore cement in depleted oil and gas reservoirs under geological CO2 sequestration conditions. A better understanding of CO2-brine-cement-rock interaction is needed to evaluate the seal integrity of candidate sequestration formation in the long run. This work investigates possible alteration of wellbore cement when bonded by different host formation rock upon exposure to CO2-saturated brine. Composite cement-sandstone and cement-limestone core samples were created to perform reactive coreflood experiments. After an eight-day dynamic flow-through period, both cores had a similar extent of porosity increase, while the cement-limestone core experienced a ten-fold higher increase in permeability. With the aid of X-ray Micro-CT imaging and Scanning Electron Microscopy, it is observed that cement underwent greater degradation at the cement-sandstone interface. Degradation of cement-limestone core mainly took place on the host rock matrix. Worm holes were developed and a solution channel was formed in the limestone, creating a dominant flow path that altered both flow and reaction behavior. Limestone buffered the injected acidic brine preventing further deterioration of cement near the core outlet. Changes in fluid chemistry of limestone and sandstone coreflood effluents are compared. Results from this work are aimed at assisting the development and validation of robust reactive transport models through direct measurement of cemented rock core porosity and permeability evolution as well as the effluent aqueous chemistry change. This will subsequently improve predictive capabilities of reactive transport models associated with CO2 sequestration in geologic environments. Permeability Evolution of Cement-Rock Core Sample during Dynamic Flow of CO2-Brine

  18. Dry hair

    MedlinePlus

    Some causes of dry hair are: Anorexia nervosa Excessive hair washing, or using harsh soaps or alcohols Excessive blow-drying Dry air Menkes kinky hair syndrome Malnutrition Underactive parathyroid ( ...

  19. The properties of Portland cement-limestone-silica fume mortars

    SciTech Connect

    Zelic, J.; Krstulovic, R.; Tkalcec, E.; Krolo, P.

    2000-01-01

    This work has studied the influence of the combined action of silica fume and limestone or strength development, porosity, pore structure and morphological features in the system where 15 wt% of cement was substituted by finely ground limestone. Silica fume was added in amounts of 0, 2, 5, 8, 11 and 15 wt% on a cement basis, respectively. It has been established that limestone addition considerably increases the total porosity of mortars. However, if introduced together with silica fume up to 8 wt% of silica, porosity decreases. More than 8 wt% of silica increases the porosity again. The cement mortar containing 8 wt% of silica fume shows the highest compressive strength, the minimum value of the total porosity, and its pore size distribution curve shows a discontinuous pore structure. Limestone is taken up to the system and reacts with aluminate and ferrite phases from cement. Approximately 5 wt% is available for reaction after 120 days hydration of mortars containing no silica fume. The quantity of limestone incorporated is affected by the silica fume content. The replacement of Portland cement by 15 wt% of silica fume causes reduction both in the amount of cement and in the free CH content available for limestone chemical activity, and in this condition limestone acts only as a filler addition.

  20. Geology of Vanport limestone (Pennsylvanian) in Elk County, Pennsylvania

    SciTech Connect

    Kuntz, T.J.

    1987-09-01

    The northernmost exposures of the Vanport limestone appear in Elk and southern McKean Counties, Pennsylvania. The Vanport limestone is structurally preserved in N45/sup 0/-50/sup 0/E trending synclinal folds. Surface exposures are almost all incomplete due to erosion. Drill-hole data assisted in defining areas of nondeposition within Elk County, variations in thickness, and erosional loss by channeling. The Vanport limestone thins to the southeast within Elk County and probably changes from limestone to a shaly limestone (transition zone) and then to shale. Analysis of 70 limestone samples indicated an average insoluble-residue content of 11.4%. The insoluble residue, mainly clay, increases toward the southeast, the direction of paleoshoreline and source of terrigenous sediments. A lack of quartz grains suggests a lack of detrital input from the source area. A study of the vertical variation of the total insoluble-residue content displayed an increase at the bottoms and tops of the stratigraphic section, mirroring the transgressive-regressive phases of the Vanport sea. The majority of allochems were skeletal material in a micritic matrix. Most abundant were mollusks, followed by forams, brachiopods, echinoderms, ostracods, and bryozoans. Composita brachiopods and pseudopunctate and/or punctate brachiopods inhabited offshore stillstand and nearshore transgressive-regressive environments, respectively. Other fossil assemblages displayed spatial and temporal variation. A darker matrix color occurred in stratigraphic sections closer to the paleoshoreline, due to higher clay and organic content. More offshore stratigraphic sections of the limestone were noticeably lighter in color.

  1. United Arab Emirates limestones: impact of petrography on thermal behavior

    NASA Astrophysics Data System (ADS)

    Alaabed, Sulaiman; Soltan, Abdel Monem; Abdelghany, Osman; Amin, Bahaa Eldin Mahmoud; El Tokhi, Mohamed; Khaleel, Abbas; Musalim, Abdullah

    2014-12-01

    The thermal behavior of selected limestones from representative localities of the United Arab Emirates is investigated for their suitability for soft-burnt lime production. The limestone samples were collected from the Ghalilah, Musandam, Shauiba, Muthaymimah, Dammam and Asmari formations. The samples were characterized for petrography, mineral and chemical composition, together with physico-mechanical characteristics. Investigative methods included transmitted light microscopy (TLM), cathodoluminescence (CLM) and scanning electron microscopy (SEM), as well as X-ray micro-tomography (μ-CT), XRD, XRF and Archimedes method. The limestone samples were fired in an electrical muffle furnace for 0.25, 0.5, 1 and 2 hours at 800, 900, 1,000 and 1,100 °C. After firing the lime grains were tested to determine their hydration rate and microfabric. The Ghalilah and Musandam limes show the lowest and highest maximum hydration rates, respectively, due mainly to the impure nature of the former, and the smaller lime crystallites and dominance of post-calcination micro-cracks of the latter. The Dammam and Asmari limes preserve a "ghost" microfabric of the original limestone. Higher allochem contents impose lower activation energy requirements for calcination, which implies earlier calcination of the allochems. The Musandam, Shauiba and Muthaymimah limestones may be useful for the production of reactive soft-burnt lime under the applied firing conditions, however, the Dammam and Asmari limestones need more advanced calcination conditions than the applied ones. The Ghalilah limestone was found to be unsuitable for the production of lime.

  2. Influence of water contained in porous limestone on corrosion

    NASA Astrophysics Data System (ADS)

    Kozłowski, R.; Hejda, A.; Cȩckiewicz, S.; Haber, J.

    The chemical degradation of porous limestone due to its reaction with sulphur dioxide was investigated by determining amounts and distributions of sulphur-containing corrosion products in samples collected from historic buildings. Water vapour adsorption equilibria have been determined for limestones of varying petrology, and correlated with sulphur dioxide uptakes measured in artificial weathering experiments. Out of several possible routes of the corrosive reaction, dissolution of sulphur dioxide in bulk water present in the stone may be related to the prevailing mechanism leading to stone deterioration. The bulk water may appear in the limestone as water condensed in the capillaries, or absorbed by hygroscopic salts.

  3. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ('THE OLD PIT') WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER. - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  4. EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EXTERIOR OVERVIEW, LOOKING NORTH, OF THIS 400' DEEP LIMESTONE QUARRY PIT ("THE OLD PIT") WITH LEDGE PREPARED FOR LIMESTONE EXTRACTION. AN ELEVEN-HOLE SHOT WILL DISLODGE APPROXIMATELY 25,000 TONS OF LIMESTONE WHICH, AFTER LOADING AND CRUSHING, WILL BE USED FOR ROAD CONSTRUCTION. THE CALERA QUARRY IS ONE OF FOUR ACTIVE VULCAN MATERIALS COMPANY QUARRIES IN THE DISTRICT. VULCAN MATERIALS, A FORTUNE 500 FIRM, ESTABLISHED IN BIRMINGHAM IN 1906 AS BIRMINGHAM SLAG COMPANY, VULCAN MATERIALS IS THE NATION'S FOREMOST PRODUCER OF CONSTRUCTION AGGREGATE AND A LEADING CHEMICALS MANUFACTURER - Vulcan Material Company, Calera Quarry, 1614 Highway 84, Calera, Shelby County, AL

  5. Silica and dolomite paragenesis in crinoidal limestones

    SciTech Connect

    Lyons, T.W.; Vahrenkamp, V.C.

    1985-01-01

    The intimate association of silica and dolomite in crinoid fragments is a commonly observed phenomenon in chert-rich carbonates of all ages. An investigation of this silica/dolomite association in some Phanerozoic examples from North America has revealed a striking cause and effect relationship between silicification and dolomitization which closely parallels the findings of Jacka (1974). Based on detailed petrographic analysis of crinoidal limestones, it is argued that dolomite forms concomitant with, and as a product of, the replacement of calcium carbonate by silica. Two possible mechanisms exist regarding the observed paragenesis: 1) silica replacement of high magnesian-calcite (HMC) mobilizes and redistributes Mg/sup 2 +/ resulting in the simultaneous partial dolomitization of the remaining HMC; this dolomite is then selectively preserved or partially replaced during continued silicification; 2) initially, metastable opal-CT being derived from the crinoid host; during the ensuing opal-CT to quartz transformation, Mg/sup 2 +/ is liberated and causes local dolomitization. Petrographic observations suggest that a significant volume of replacement dolomite can be generated from a local source of Mg/sup 2 +/, here the HMC crinoid host. Dolomitization occurred during early diagenesis prior to the stabilization of HMC to LMC possibly in a mixed-water environment. Low temperature natural co-precipitation of quartz and dolomite may provide an alternative mechanism whereby the oxygen isotopic fractionation between water and dolomite could be calculated.

  6. Residual CO2 trapping in Indiana limestone.

    PubMed

    El-Maghraby, Rehab M; Blunt, Martin J

    2013-01-01

    We performed core flooding experiments on Indiana limestone using the porous plate method to measure the amount of trapped CO(2) at a temperature of 50 °C and two pressures: 4.2 and 9 MPa. Brine was mixed with CO(2) for equilibration, then the mixture was circulated through a sacrificial core. Porosity and permeability tests conducted before and after 884 h of continuous core flooding confirmed negligible dissolution. A trapping curve for supercritical (sc)CO(2) in Indiana showing the relationship between the initial and residual CO(2) saturations was measured and compared with that of gaseous CO(2). The results were also compared with scCO(2) trapping in Berea sandstone at the same conditions. A scCO(2) residual trapping end point of 23.7% was observed, indicating slightly less trapping of scCO(2) in Indiana carbonates than in Berea sandstone. There is less trapping for gaseous CO(2) (end point of 18.8%). The system appears to be more water-wet under scCO(2) conditions, which is different from the trend observed in Berea; we hypothesize that this is due to the greater concentration of Ca(2+) in brine at higher pressure. Our work indicates that capillary trapping could contribute to the immobilization of CO(2) in carbonate aquifers.

  7. Acid mine treatment with open limestone channels

    SciTech Connect

    Ziemkiewicz, P.F.; Brant, D.L.; Skousen, J.G.

    1996-12-31

    Acid mine drainage (AMD) is often associated with mining of pyritic coal and metal deposits. Typical AMD associated with coal mines in the eastern US can have acidity and iron concentrations ranging from the teens to the thousands of mg/l. Aluminum and manganese can be present in concentrations ranging from zero to the low hundreds of mg/l. Much attention has been devoted to developing inexpensive, limestone (LS)-based systems for treating AMID with little or no maintenance. However, LS tends to coat with metal hydroxides when exposed to AMID in an oxidized state, a process known as {open_quotes}armoring{close_quotes}. It is generally assumed that once armored, LS ceases to neutralize acid. Another problem is that the hydroxides tend to settle into plug the pore spaces in LS beds forcing water to move around rather than through the LS. While both are caused by the precipitation of metal hydroxides, armoring and plugging are two different problems. Plugging of LS pores can be avoided by maintaining a high flushing rate through the LS bed. Armoring, however, occurs regardless of water velocity. This study investigated the influence of armoring on LS solubility and the implications of armoring and plugging on the construction of open (oxidizing) LS channels for treating AMD. We evaluated the AMID treatment performance of armored and unarmored LS in oxidizing environments both in laboratory and field studies.

  8. The conservation of Britain's limestone cave resource

    NASA Astrophysics Data System (ADS)

    Hardwick, P.; Gunn, J.

    1996-10-01

    Limestone caves are an important scientific and recreational resource in Britain. During the mid- to late 1970s, cavers and statutory conservation bodies cooperated in a review of cave resources which resulted in the designation of 48 caves or cave areas as Sites of Special Scientific Interest (SSSI). During the same period, the Wildlife and Countryside Act 1981 was introduced to provide more effective planning controls on activities such as agriculture carried out within SSSI boundaries. In one case, at Priddy in the Mendip Hills of Somerset, landowners prevented access to a number of caves in protest over the new, tougher restrictions on agriculture. Faced with the closure, and perceiving that their recreational use of caves might also be controlled, local cavers joined the landowners in opposing the proposals for SSSI designation. As a result the proposals were reviewed, three caves were excluded from the site and controls on the remaining area were relaxed. The case emphasized a need for an effective system to take account of all factors affecting cave conservation, a need which has led to a more constructive dialogue between nature conservation bodies, caver organizations and other interested parties.

  9. High temperature H{sub 2}S removal using limestones

    SciTech Connect

    Cairns, E.J.; Lynn, S.

    1995-12-31

    This project is exploring the technical and economic feasibility of using limestone in a high determine process for cleaning coal gas prior to combustion in a gas turbine. In one version of the process the coal gas would pass counter-currently through a nearly-isothermal, moving bed of limestone that would serve to remove particulates (by filtration), and hydrogen sulfide (by chemisorption), and ammonia (by catalysis). Alternative process configurations include the use of limestone in a cocurrently moving bed, in a fluidized bed, or in an entrained flow sorption system. The objectives of this research have been to define the range of temperatures at which these goals can best be realized at a given pressure, to determine the effect of the magnesium content of the limestone on sulfidation kinetics and calcium utilization, to use the kinetic data to model the various types of sorption systems, and to develop a process for converting calcium sulfide to elemental sulfur and calcium carbonate.

  10. LUTETIAN LIMESTONES IN THE PARIS REGION: PETROGRAPHIC AND COMPOSITIONAL EXAMINATION

    SciTech Connect

    BLANC,A.; HOLMES,L.L.; HARBOTTLE,G.

    1998-06-11

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific-stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemist whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  11. Lutetian limestones in the Paris region: Petrographic and compositional examination

    SciTech Connect

    Blanc, A.; Holmes, L.L.; Harbottle, G.

    1998-12-31

    Stone for building and decorating monuments in the Paris Basin from antiquity to the present came from numerous quarries in the Lutetian limestone formations of the region. To identify specific stone sources used for masonry and sculptures in these monuments, a team of geologists and archaeologists have investigated 300 quarries and collected 2,300 limestone samples for study in a collaborative effort by geologists and chemists. Petrographic and paleontologic examinations of thin sections enable geologists to distinguish the Tertiary Lutetian limestones from similar stone in Jurassic and Cretaceous strata. The methods of the geologist have been supplemented by those of the chemistry whose compositional studies by neutron activation analysis can differentiate among the fine-grained upper Lutetian limestones extracted from specific ancient quarries.

  12. 1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SOUTH FACADE. CONSTRUCTED (ca. 1895) OF INDIGENOUS LIMESTONE AND USED AS LOCKPORTS CENTRAL HIGH SCHOOL FOR MORE THAN SIXTY YEARS. - Lockport Historic District, Central High School, Lockport, Will County, IL

  13. Limestone - A Crucial and Versatile Industrial Mineral Commodity

    USGS Publications Warehouse

    Bliss, James D.; Hayes, Timothy S.; Orris, Greta J.

    2008-01-01

    Limestone, as used by the minerals industry, is any rock composed mostly of calcium carbonate (CaCO3). Although limestone is common in many parts of the United States, it is critically absent from some. Limestone is used to produce Portland cement, as aggregate in concrete and asphalt, and in an enormous array of other products, making it a truly versatile commodity. Portland cement is essential to the building industry, but despite our Nation's abundance of limestone, there have been cement shortages in recent years. These have been caused in part by a need to find new areas suitable for quarrying operations. To help manage our Nation's resources of such essential mineral commodities, the U.S. Geological Survey (USGS) provides crucial data and scientific information to industry, policymakers, and the public.

  14. Low temperature dry scrubbing reaction kinetics and mechanisms, Volume 2

    SciTech Connect

    Prudich, M.E.; Sampson, K.J.; Reddy, S.N.; Maldei, M.; Ben-Said, L. )

    1992-10-01

    A novel wet/dry desulfurization post-Furnace process (ETS' Limestone Emission control (LEC) process) for SO[sub 2] removal has been described by Prudich et al.(1988). In this process hot flue gases are contacted with a bed of quarry-sized (1/4in. to 1/32in.) wet limestone granules. This thesis represents the development of a second generation model of ETS' LEC process. The first generation model developed by Prudich et al.(1988) the use of a fixed limestone bed. The work done on this has been well documented by Appell (1989) and Visneski (1991) process under consideration for this thesis involves a continuously moving limestone bed. The moving bed simplifies the process flowsheet and facilitates limestone reactivation. The moving-bed LEC process involves the use of a cross-flow pattern with the flue gas flowing horizontally across the limestone bed at speeds of around 1 to 2 feet per second and the limestone moving vertically downward through the LEC reactor at speeds of around 1 to 15 feet per hour. The primary parameters considered in the mathematical modeling of the moving-bed LEC process are inlet sulfur dioxide concentration, inlet gas-phase water concentration, inlet flue gas and limestone temperatures and water spray addition rate over the bed. For solution of the process, mass and energy balance equations derived as a function of the positions of the flue gas limestone are solved using a predictor-corrector method. The Adams-Bashforth (modified Euler's) method is used with a second order corrector.

  15. Influence of limestone on the hydration of Portland cements

    SciTech Connect

    Lothenbach, Barbara Le Saout, Gwenn; Gallucci, Emmanuel; Scrivener, Karen

    2008-06-15

    The influence of the presence of limestone on the hydration of Portland cement was investigated. Blending of Portland cement with limestone was found to influence the hydrate assemblage of the hydrated cement. Thermodynamic calculations as well as experimental observations indicated that in the presence of limestone, monocarbonate instead of monosulfate was stable. Thermodynamic modelling showed that the stabilisation of monocarbonate in the presence of limestone indirectly stabilised ettringite leading to a corresponding increase of the total volume of the hydrate phase and a decrease of porosity. The measured difference in porosity between the 'limestone-free' cement, which contained less than 0.3% CO{sub 2}, and a cement containing 4% limestone, however, was much smaller than calculated. Coupling of thermodynamic modelling with a set of kinetic equations which described the dissolution of the clinker, predicted quantitatively the amount of hydrates. The quantities of ettringite, portlandite and amorphous phase as determined by TGA and XRD agreed well with the calculated amounts of these phases after different periods of time. The findings in this paper show that changes in the bulk composition of hydrating cements can be followed by coupled thermodynamic models. Comparison between experimental and modelled data helps to understand in more detail the dominating processes during cement hydration.

  16. Pegfilgrastim Injection

    MedlinePlus

    ... a pre-filled automatic injection device (On-body Injector) to inject subcutaneously (under the skin). If you ... a pre-filled automatic injection device (On-body Injector), the device will usually be applied to your ...

  17. Cabazitaxel Injection

    MedlinePlus

    ... injection is used along with prednisone to treat prostate cancer (cancer of a male reproductive organ) that has ... cabazitaxel injection is usually used in men with prostate cancer. If used by pregnant women, cabazitaxel injection can ...

  18. Morphine Injection

    MedlinePlus

    Morphine injection is used to relieve moderate to severe pain. Morphine is in a class of medications called opiate ( ... Morphine injection comes as a solution (liquid) to inject intramuscularly (into a muscle) or intravenously (into a ...

  19. Romidepsin Injection

    MedlinePlus

    Romidepsin injection is used to treat cutaneous T-cell lymphoma (CTCL; a group of cancers of the ... other medication given by mouth or by injection. Romidepsin injection is in a class of medications called ...

  20. Evaluation of a surface application of limestone for controlling acid mine discharges from abandoned strip mines, Sewellsville, Ohio

    SciTech Connect

    Geidel, G.

    1982-01-01

    A 150 acre drainage basin in an unreclaimed coal strip mine in east-central Ohio was studied and extensively monitored to determine the effect of a surface application of limestone on the ground water quality. Prior to the limestone treatment the ground and surface water of the basin was acidic due to pyrite oxidation in the spoil. In order to assess the effect of limestone application the basin was divided into seven sub-basins, five of which were treated. Various halide salts were also applied in order to ascertain the rate of ground water movement through the spoil. Twenty-six seeps draining the seven basins were monitored on a weekly basis for temperature, pH, acidity, alkalinity, conductivity and the tracers and once a month for sulfate. A recording rain gage was set up in the area and a weekly composite of precipitation was analyzed. The seeps from the sub-basins with low acid concentrations became alkaline due to neutralization but after a long dry period, they returned to their acid condition. The moderately and highly acidic seeps showed a decline in the acid concentrations which could be attributed to a combination of neutralization and a decrease in the rate of pyrite oxidation. The results of this field study and simultaneous laboratory experiments showed that the maximum amount of alkalinity that can be generated by a surface application of limestone is not sufficient to reduce the ground water acidity generated by pyrite oxidation. Additionally, the amount of limestone applied was not sufficient to significantly decrease the rate of pyrite oxidation nor provide neutralization and thereby produce neutral or alkaline discharges from the abandoned coal strip mine sites.

  1. Attrition of limestone by impact loading in fluidized beds

    SciTech Connect

    Fabrizio Scala; Fabio Montagnaro; Piero Salatino

    2007-09-15

    The present study addresses limestone attrition and fragmentation associated with impact loading, a process which may occur extensively in various regions of fluidized bed (FB) combustors/gasifiers, primarily the jetting region of the bottom bed, the exit region of the riser, and the cyclone. An experimental protocol for the characterization of the propensity of limestone to undergo attrition/fragmentation by impact loading is reported. The application of the protocol is demonstrated with reference to an Italian limestone whose primary fragmentation and attrition by surface wear have already been characterized in previous studies. The experimental procedure is based on the characterization of the amount and particle size distribution of the debris generated upon the impact of samples of sorbent particles against a target. Experiments were carried out at a range of particle impact velocities between 10 and 45 m/s, consistent with jet velocities corresponding to typical pressure drops across FB gas distributors. The protocol has been applied to either raw or preprocessed limestone samples. In particular, the effect of calcination, sulfation, and calcination/recarbonation cycles on the impact damage suffered by sorbent particles has been assessed. The measurement of particle voidage and pore size distribution by mercury intrusion was also accomplished to correlate fragmentation with the structural properties of the sorbent samples. Fragmentation by impact loading of the limestone is significant. Lime displays the largest propensity to undergo impact damage, followed by the sorbent sulfated to exhaustion, the recarbonated sorbent, and the raw limestone. Fragmentation of the raw limestone and of the sulfated lime follows a pattern typical of the failure of brittle materials. The fragmentation behavior of lime and recarbonated lime better conforms to a disintegration failure mode, with an extensive generation of very fine fragments. 27 refs., 9 figs. 1 tab.

  2. Dry Mouth

    MedlinePlus

    Dry mouth is the feeling that there is not enough saliva in your mouth. Everyone has a dry mouth once in a while - if they are nervous, ... under stress. But if you have a dry mouth all or most of the time, it can ...

  3. Pilot-scale Limestone Emission Control (LEC) process: A development project. Volume 1, Main report and appendices A, B, C, and D: Final report

    SciTech Connect

    Prudich, M.E.; Appell, K.W.; McKenna, J.D.

    1994-03-01

    ETS, Inc., a pollution consulting firm with headquarters in Roanoke, Virginia, has developed a dry, limestone-based flue gas desulfurization (FGD) system. This SO{sub 2} removal system, called Limestone Emission Control (LEC), can be designed for installation on either new or existing coal-fired boilers. In the LEC process, the SO{sub 2} in the flue gas reacts with wetted granular limestone that is contained in a moving bed. A surface layer of principally calcium sulfate (CaSO{sub 4}) is formed on the limestone. Periodic removal of this surface layer by mechanical agitation allows high utilization of the limestone granules. A nominal 5,000 acfm LEC pilot plant has been designed, fabricated and installed on the slipstream of a 70,000 pph stoker boiler providing steam to Ohio University`s Athens, Ohio campus. A total of over 90 experimental trials have been performed using the pilot-scale moving-bed LEC dry scrubber as a part of this research project with run times ranging up to a high of 125 hours. SO{sub 2} removal efficiencies as high as 99.9% were achievable for all experimental conditions studied during which sufficient humidification was added to the LEC bed. The LEC process and conventional limestone scrubbing have been compared on an equatable basis using flue gas conditions that would be expected at the outlet of the electrostatic precipitator (ESP) of a 500 MW coal-fired power plant. The LEC was found to have a definite economic advantage in both direct capital costs and operating costs. Based on the success and findings of the present project, the next step in LEC process development will be a full-scale commercial demonstration unit.

  4. [Intra-articular injections].

    PubMed

    Chapelle, Ch

    2015-09-01

    It is not unusual for a specialist or general practitioner to be presented with a pathology which necessitates the use of an intra-articular injection of corticosteroids, hyaluronic acid or a local anaesthetic. It would seem to be interesting to update and to precise the techniques and methods of intraarticular injections which have appeared in recent international publications, when we know that 30 % of the injections given into the knee and so called "dry" are incorrect and, therefore, inefficient. The indication of an articular injection depends, firstly, on the diagnosis which should be done with great care; after which should be an objective analysis complete with secondary effects linked to both the injection and the product used. The conditions of asepsis, the choice of needles and quantities of the injection and even the ways of the injections should be reviewed in detail. The last studies clearly question the secondary effects of the cartilage degradations of the cortisone given as an intra-articular injection and shows its efficiency on the pain and inflammatory phenomonen in osteoarthritis. Studies on hyaluronic acid are often contradictory going from a modest result to an important pain relief but it is necessary to be aware that the objective criteria are difficult to interpret. The use of local anaesthetics in intra-articular is limited by the few indications in view of the major risk of aggravating the pre-existing lesions by the disappearing signs of pain.

  5. Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 2. Chemical retention from diffusion and slow advection

    USGS Publications Warehouse

    Shapiro, A.M.; Renken, R.A.; Harvey, R.W.; Zygnerski, M.R.; Metge, D.W.

    2008-01-01

    A tracer experiment, using a nonreactive tracer, was conducted as part of an investigation of the potential for chemical and pathogen migration to public supply wells that draw groundwater from the highly transmissive karst limestone of the Biscayne aquifer in southeastern Florida. The tracer was injected into the formation over approximately 1 h, and its recovery was monitored at a pumping well approximately 100 m from the injection well. The first detection of the tracer occurred after approximately 5 h, and the peak concentration occurred at about 8 h after the injection. The tracer was still detected in the production well more than 6 days after injection, and only 42% of the tracer mass was recovered. It is hypothesized that a combination of chemical diffusion and slow advection resulted in significant retention of the tracer in the formation, despite the high transmissivity of the karst limestone. The tail of the breakthrough curve exhibited a straight-line behavior with a slope of -2 on a log-log plot of concentration versus time. The -2 slope is hypothesized to be a function of slow advection, where the velocities of flow paths are hypothesized to range over several orders of magnitude. The flow paths having the slowest velocities result in a response similar to chemical diffusion. Chemical diffusion, due to chemical gradients, is still ongoing during the declining limb of the breakthrough curve, but this process is dwarfed by the magnitude of the mass flux by slow advection.

  6. Modifying the properties of finely ground limestone by tumbling granulation

    NASA Astrophysics Data System (ADS)

    Macho, Oliver; Eckert, Maroš; Tomášová, Barbora; Peciar, Peter; Ščasný, Martin; Fekete, Roman; Peciar, Marián

    2016-06-01

    Calcium carbonate in the form of finely ground limestone is a material that has found its application in a wide range of industries, in the chemical, rubber, agricultural, and paper industries, is used for desulfurization of boilers and other. In civil engineering, ground limestone is used for the production of building materials, plaster and mortar mixtures, as a filler in concrete mixtures, in road construction, and as an essential component of mastic asphalt. This paper deals with examining the modification of the properties of finely ground limestone by the tumbling agglomeration method. It has been shown that the components of concrete with a round grain have a positive effect on the pumping of concrete in comparison with an elongated grain or the rough surface of crushed stone. The experiments will be carried out on a granulation plate using a variety of granulation liquid. The agglomerates and their properties were compared with untreated finely ground limestone, with a focus on detecting changes in compressibility, density and particle size. The output of this paper is a description and graphical representation of the changes in the properties of ground limestone before and after the agglomeration process.

  7. Thermo-Hydro-Mechanical-Chemical Coupled Modeling of Geothermal Doublet Systems in Limestones -revised

    NASA Astrophysics Data System (ADS)

    Rühaak, Wolfram; Heldmann, Claus-Dieter; Pei, Liang; Bartels, Jörn; Weinert, Sebastian; Sass, Ingo

    2016-04-01

    Limestone aquifers in Southern Germany have been used within the last decade very successfully for geothermal heating and - to a lesser extent - for power generation. As an example the region around Munich has been extensively explored. While the extent of usage of this reservoir is increasing there is also an increased interest in better understanding of the reservoir properties and its change in the course of operation. For instance, the observed production and injection pressures are partly hard to explain. They may be related to mechanical or chemical processes, or both. Based on extensive data of outcrop studies and drillings, a data-base for the relevant physical properties of the respective limestones has been complied. The data include thermal conductivity, density, specific heat capacity, permeability, as well as mechanical properties like thermal expansion coefficient and elasticity modules. By using the hydro-thermo-chemical simulator FEFLOW together with an extension for thermo- and hydro-mechanical coupling the relevant processes are studied and compared with observed data. At the EGU Meeting in 2015 results of an initial study have been presented. This time results based on a completely new model setup and also using newly developed code will be presented. As a conclusion main challenges while modeling THMC fracture flow by using a multi-continua approach will be discussed.

  8. Novel Hydroxyapatite Coatings for the Conservation of Marble and Limestone

    NASA Astrophysics Data System (ADS)

    Naidu, Sonia

    Marble and limestone are calcite-based materials used in the construction of various structures, many of which have significant artistic and architectural value. Unfortunately, due to calcite's high dissolution rate, these stones are susceptible to chemically-induced weathering in nature. Limestone, due to its inherent porosity, also faces other environmental weathering processes that cause weakening from disintegration at grain boundaries. The treatments presently available are all deficient in one way or another. The aim of this work is to examine the feasibility of using hydroxyapatite (HAP) as a novel protective coating for marble and limestone, with two goals: i) to reduce acid corrosion of marble and ii) to consolidate physically weathered limestone. The motivation for using HAP is its low dissolution rate and structural compatibility with calcite. Mild, wet chemical synthesis routes, in which inorganic phosphate-based solutions were reacted with marble and limestone, alone and with other precursors, were used to produce HAP films. Film nucleation, growth and phase evolution were studied on marble to understand film formation and determine the optimal synthesis route. An acid resistance test was developed to investigate the attack mechanism on marble and quantify the efficacy of HAP-based coatings. Film nucleation and growth were dependent on substrate surface roughness and increased with calcium and carbonate salt additions during synthesis. Acid attack on marble occurred via simultaneous dissolution at grain boundaries, twin boundaries and grain surfaces. HAP provided intermediate protection against acid attack, when compared to two conventional treatments. Its ability to protect the stone from acid was not as significant as predicted from dissolution kinetics and this was attributed to incomplete coverage and residual porosity within the film, arising from its flake-like crystal growth habit, which enabled acid to access the underlying substrate. The

  9. The Ançã limestones, Coimbra, Portugal

    NASA Astrophysics Data System (ADS)

    Quinta-Ferreira, Mário; Gil Catarino, Lídia; Delgado Rodrigues, José

    2016-04-01

    Ançã is located in the Lusitanian Basin (western Meso-Cenozoic sedimentary basin), in the municipality of Cantanhede, close to Coimbra, Portugal. This constitutes the northernmost Dogger (Bajocian) limestone sequence in Portugal. The use of the Ançã limestones is documented since the Roman occupation of the Iberian Peninsula. It was used for the construction of houses, palaces, churches, fine sculptures, carving, paving and for the production of lime. These limestones vary from white and very soft varieties, with very high porosity used for sculpture and carving to white and hard varieties used for masonry and as aggregates and to white to bluish with low porosity and high strength varieties, mainly used for paving. The softer and whiter variety is worldwide known as Ançã Stone (Pedra de Ançã) exhibiting a porosity of 26-29 %. It became famous after being largely used by Coimbra most famous Renaissance sculptors like João de Ruão and Nicolau de Chanterenne. The Pedra de Ançã was used mainly in the region of Coimbra, but also in several other places in Portugal, in Santiago de Compostela, Spain, and Brazil. Some examples of heritage in Coimbra using the Pedra de Ançã are the renaissance portal of the Saint Cross Church, the tombs of the first two Portuguese kings located in this church, the altar of the Saint Cross Church or of the Old Cathedral, or in sculptures at the University of Coimbra. It is quite prone to deteriorate when exposed to atmospheric agents and to soluble salts, mainly due to its high porosity. Deteriorated surfaces needing treatment constitute difficult conservation problems, especially when consolidation and protection treatments are required. The less porous varieties of the Ançã limestones (< 20 % porosity) were mainly used for masonry, paving and production of lime. The royal Palace of Buçaco is a remarkable masonry building constructed at the end of the XIX century with the less porous varieties of the Ançã limestones

  10. Leaching of clay minerals in a limestone environment

    USGS Publications Warehouse

    Carroll, D.; Starkey, H.C.

    1959-01-01

    Water saturated with CO2 at about 25??C was percolated through mixed beds of limestone or marble fragments and montmorillonite, "illite" and kaolinite in polyethylene tubes for six and fortyfive complete runs. The leachates were analysed for SiO2, A12O3 and Fe2O3, but only SiO2 was found. The minerals lost SiO2 in this order: montmorillonite > kaolinite > "illite". The differential removal of SiO2 during the short period of these experiments suggests a mechanism for the accumulation of bauxite deposits associated with limestones. ?? 1959.

  11. Limestone calcination with CO{sub 2} capture (III): characteristics of coal combustion during limestone decomposition

    SciTech Connect

    Yin Wang; Shiying Lin; Yoshizo Suzuki

    2009-05-15

    In this study, the combustion characteristics of coal in CO{sub 2}/O{sub 2} and steam/CO{sub 2}/O{sub 2} atmospheres were investigated during limestone decomposition in a continuously operating fluidized bed reactor for CO{sub 2} capture. The results show that the variations and concentrations of CO, CH{sub 4}, and H{sub 2} in the exhaust gas of the reactor in the steam/CO{sub 2}/O{sub 2} atmosphere were smaller than those in the CO{sub 2}/O{sub 2} atmosphere. Because of steam dilution, the CO{sub 2} concentration in the bed was lower in the steam/CO{sub 2}/O{sub 2} atmosphere than that in the CO{sub 2}/O{sub 2} atmosphere, and the effect of differential pressure variation on limestone decomposition in the fluidized bed was less pronounced in the steam/CO{sub 2}/O{sub 2} atmosphere than that in the CO{sub 2}/O{sub 2} atmosphere. Additionally, N{sub 2}O emission was detected only in the CO{sub 2}/O{sub 2} atmosphere, and the conversion of N to NO in the steam dilution atmosphere was of a smaller magnitude than that observed in the CO{sub 2}/O{sub 2} atmosphere. We also found that the conversion of S to SO{sub 2} in the steam/CO{sub 2}/O{sub 2} atmosphere was lower than that observed in the CO{sub 2}/O{sub 2} atmosphere. The contents of sulfur, SiO{sub 2}, and Al{sub 2}O{sub 3} were much higher in solid samples located in the cyclone than in the overflow holder in both steam/CO{sub 2}/O{sub 2} and CO{sub 2}/O{sub 2} atmospheres. Finally, the hydration and carbonation reactivities of CaO produced in the steam/CO{sub 2}/O{sub 2} atmosphere were better than those produced in the CO{sub 2}/O{sub 2} atmosphere. 13 refs., 14 figs., 3 tabs.

  12. STRUCTURAL CHANGES IN SURFACTANT-MODIFIED SORBENTS DURING FURNACE INJECTION

    EPA Science Inventory

    A calcium hydroxide [Ca(OH)2] sorbent modified by the addition of calcium lignosulfonate has recently been developed for use in the Environmental Protection Agency's limestone injection multistage burner process. The increased reactivity with sulfur dioxide (SO2) displayed by thi...

  13. Rain underscores need for injection

    SciTech Connect

    Stelling, K.F.

    1996-01-01

    Since 1987, steam production totals at The Geysers Geothermal field have fallen and water injection totals have remained quite stable, except for the unusually dry winter months of 1994 when injection fell by a record amount. The heavy rainfall in the first half of 1995 altered the long-term production and injection patterns and underscored the need to increase injection in the field. From January to June 1995, steam production at The Geysers was reduced by 37 percent form the amount produced during the same period in 1994--because the rain increased availability of hydroelectric power. At the same time, water injection in the field rose by 25 percent because more rainwater was available for injection. Consequently, both reservoir pressure and available steam reserves grew, and most power plants that returned on line in the second half of the year produced more megawatts with less steam. This confirmed findings form several injection studies at The Geyser`s.

  14. Adalimumab Injection

    MedlinePlus

    ... not improved when treated with other medications, ulcerative colitis (a condition which causes swelling and sores in ... adalimumab injection to treat Crohn's disease or ulcerative colitis, your doctor may tell you to inject the ...

  15. Denosumab Injection

    MedlinePlus

    ... Denosumab injection (Prolia) is also used to treat bone loss in men with prostate cancer and in women with breast cancer who are receiving certain treatments that increase their risk for fractures. Denosumab injection ( ...

  16. Diphenhydramine Injection

    MedlinePlus

    ... the nervous system that causes difficulties with movement, muscle control, and balance). Diphenhydramine injection should not be ... solution (liquid) to be injected intramuscularly (into a muscle) or intravenously (into a vein). Your dosing schedule ...

  17. Leucovorin Injection

    MedlinePlus

    ... red blood cells) caused by low levels of folic acid in the body. Leucovorin injection is also used ... injection is in a class of medications called folic acid analogs. It treats people who are receiving methotrexate ...

  18. Glatiramer Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS; a disease in which ... to inject glatiramer, inject it around the same time every day. Follow the directions on your prescription ...

  19. Naltrexone Injection

    MedlinePlus

    Naltrexone injection is used along with counseling and social support to help people who have stopped drinking large ... injection is also used along with counseling and social support to help people who have stopped abusing opiate ...

  20. Estrogen Injection

    MedlinePlus

    ... forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) ... If you are using estrogen injection to treat hot flushes, your symptoms should improve within 1 to ...

  1. Cefazolin Injection

    MedlinePlus

    Cefazolin injection is also sometimes used for certain penicillin allergic patients who have a heart condition and ... injection is also sometimes used to treat certain penicillin allergic women who are in labor in order ...

  2. Paclitaxel Injection

    MedlinePlus

    ... with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to treat ovarian cancer (cancer that ... cancer, and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also used to treat Kaposi's sarcoma (a ...

  3. Aripiprazole Injection

    MedlinePlus

    ... aripiprazole injection and aripiprazole extended-release injection developed gambling problems or other intense urges or behaviors that ... even if you do not realize that your gambling or any other intense urges or unusual behaviors ...

  4. Testosterone Injection

    MedlinePlus

    ... Testopel) are also used to stimulate puberty in males with delayed puberty. Testosterone enanthate (Delatestryl) injection may ... to the growth, development, and functioning of the male sexual organs and typical male characteristics. Testosterone injection ...

  5. Degarelix Injection

    MedlinePlus

    Degarelix injection is used to treat advanced prostate cancer (cancer that begins in the prostate [a male reproductive gland]). Degarelix injection is in a class of medications called gonadotropin-releasing hormone (GnRH) ...

  6. Naloxone Injection

    MedlinePlus

    ... injection device.The automatic injection device has an electronic voice system that provides step by step directions ... of opiate withdrawal such as body aches, diarrhea, fast heart beat, fever, runny nose, sneezing, sweating, yawning, ...

  7. Cefoxitin Injection

    MedlinePlus

    ... injection is used to treat infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephamycin antibiotics. It works by killing bacteria.Antibiotics such as cefoxitin injection will not work ...

  8. Doripenem Injection

    MedlinePlus

    ... tract, kidney, and abdomen that are caused by bacteria. Doripenem injection is not approved by the Food ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as doripenem injection will not work ...

  9. Chloramphenicol Injection

    MedlinePlus

    ... treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection ... antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work ...

  10. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone subcutaneous injection is also used to treat endometriosis (a condition in which the type of tissue ... parts of the body in women who have endometriosis. Medroxyprogesterone injection is a very effective method of ...

  11. Levoleucovorin Injection

    MedlinePlus

    ... injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall) when methotrexate is used to to treat certain types of ... people who have accidentally received an overdose of methotrexate or similar medications. Levoleucovorin injection is in a ...

  12. Vancomycin Injection

    MedlinePlus

    Vancomycin injection is used alone or in combination with other medications to treat certain serious infections such ... infections of the lungs, skin, blood, and bones. Vancomycin injection is in a class of medications called ...

  13. Laboratory Investigations in Support of Carbon Dioxide-Limestone Sequestration in the Ocean

    SciTech Connect

    Dan Golomb; Eugene Barry; David Ryan; Carl Lawton; Stephen Pennell; Peter Swett; Huishan Duan; Michael Woods

    2005-11-01

    This semi-annual progress reports includes further findings on CO{sub 2}-in-Water (C/W) emulsions stabilized by fine particles. In previous semi-annual reports we described the formation of stable C/W emulsions using pulverized limestone (CaCO{sub 3}), flyash, beach sand, shale and lizardite, a rock rich in magnesium silicate. For the creation of these emulsions we used a High-Pressure Batch Reactor (HPBR) equipped with view windows for illumination and video camera recording. For deep ocean sequestration, a C/W emulsion using pulverized limestone may be the most suitable. (a) Limestone (mainly CaCO{sub 3}) is cheap and plentiful; (b) limestone is innocuous for marine organisms (in fact, it is the natural ingredient of shells and corals); (c) it buffers the carbonic acid that forms when CO{sub 2} dissolves in water. For large-scale sequestration of a CO{sub 2}/H{sub 2}O/CaCO{sub 3} emulsion a device is needed that mixes the ingredients, liquid carbon dioxide, seawater, and a slurry of pulverized limestone in seawater continuously, rather than incrementally as in a batch reactor. A practical mixing device is a Kenics-type static mixer. The static mixer has no moving parts, and the shear force for mixing is provided by the hydrostatic pressure of liquid CO{sub 2} and CaCO{sub 3} slurry in the delivery pipes from the shore to the disposal depth. This semi-annual progress report is dedicated to the description of the static mixer and the results that have been obtained using a bench-scale static mixer for the continuous formation of a CO{sub 2}/H{sub 2}O/CaCO{sub 3} emulsion. The static mixer has an ID of 0.63 cm, length 23.5 cm, number of baffles 27. Under pressure, a slurry of CaCO{sub 3} in artificial seawater (3.5% by weight NaCl) and liquid CO{sub 2} are co-injected into the mixer. From the mixer, the resulting emulsion flows into a Jerguson cell with two oblong windows on opposite sides, then it is vented. A fully ported ball valve inserted after the Jerguson

  14. The Solnhofen Limestone: A stony heritage of many uses

    NASA Astrophysics Data System (ADS)

    Kölbl-Ebert, Martina; Kramar, Sabina; Cooper, Barry J.

    2016-04-01

    High above the valley of the River Altmühl (Bavaria, Germany), between Solnhofen to the west and Kelheim to the east, numerous quarries give access to thinly plated limestone from the Upper Jurassic, some 150 million years before the present. The main quarry areas lie around the town of Eichstätt and between the villages of Solnhofen, Langenaltheim and Mörnsheim. Here limestone slabs have been quarried for several hundred years, some even in Roman times. Solnhofen Limestone is famous worldwide; not only because it is a beautiful building stone of high quality, but also because of the exceptionally well-preserved fossils it contains -among them the early bird Archaeopteryx. The quarry industry between Solnhofen and Eichstätt has shaped a cultural landscape, with old and new quarries sunk into the plain and numerous spoil heaps rising above it, for the rock is not all economically useful. But many of the spoil heaps and the old quarries are environmentally protected as they provide a habitat for some rare plants and animals. It is not necessary to cut the Solnhofen Limestone with a saw: it is split by hand into thin and even slabs or sheets which are used for flagstones and wall covers, which since centuries are sold world-wide. Locally it also serves as roof tiles for traditional houses. Thick slabs of especially fine quality may be found near Solnhofen and Mörnsheim and are used for lithography printing.

  15. Detail view to show one of the limestone relief panels ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view to show one of the limestone relief panels depicting one of the agencies of the Commerce Department, here the Lighthouse Service - United States Department of Commerce, Bounded by Fourteenth, Fifteenth, and E streets and Constitution Avenue, Washington, District of Columbia, DC

  16. Soil respiration patterns and controls in limestone cedar glades

    USGS Publications Warehouse

    Cartwright, Jennifer M.; Hui, Dafeng

    2015-01-01

    Soil depth, SOM, and vegetation cover were important drivers of Rs in limestone cedar glades. Seasonal Rs patterns reflected those for mesic temperate grasslands more than for semi-arid ecosystems, in that Rs primarily tracked temperature for most of the year.

  17. View of the main entrance with basrelief limestone panel designed ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of the main entrance with bas-relief limestone panel designed by C. Paul Jennwein upon which is inscribed "Lege Atque Ordine Omnia Fiunt" (translated as by law and order all is accomplished) - United States Department of Justice, Constitution Avenue between Ninth & Tenth Streets, Northwest, Washington, District of Columbia, DC

  18. The influence of additives on rheological properties of limestone slurry

    NASA Astrophysics Data System (ADS)

    Jaworska, B.; Bartosik, A.

    2014-08-01

    Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered for re-circulation. Collected at the bottom of the tank sludge is deposited in a landfill located on the premises. Rheological properties of limestone slurry hinder its further free transport in the pipeline due to generated flow resistance. To improve this state of affairs, chemical treatment of drilling fluid, could be applied, of which the main task is to give the slurry properties suitable for the conditions encountered in hydrotransport. This treatment consists of applying chemical additives to slurry in sufficient quantity. Such additives are called as deflocculants or thinners or dispersants, and are chemical compounds which added to aqueous solution are intended to push away suspended particles from each other. The paper presents the results of research allowing reduction of shear stress in limestone slurry. Results demonstrate rheological properties of limestone slurry with and without the addition of modified substances which causes decrease of slurry viscosity, and as a consequence slurry shear stress for adopted shear rate. Achieving the desired effects increases the degree of dispersion of the solid phase suspended in the carrier liquid and improving its ability to smooth flow with decreased friction.

  19. Curved limestone wall at east end of rail yard. Note ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Curved limestone wall at east end of rail yard. Note cut off valves at base of stump in right foreground, and utility tunnel in middle distance, superindent's house at right, looking NW. - Grand Canyon Village Utilities, Grand Canyon National Park, Grand Canyon Village, Coconino County, AZ

  20. Isotopic labeling for the understanding of the alteration of limestone used in built cultural heritage

    NASA Astrophysics Data System (ADS)

    Saheb, Mandana; Chabas, Anne; Mertz, Jean-Didier; Rozenbaum, Olivier; Verney-Carron, Aurélie

    2015-04-01

    This project belongs to a specific work aiming at developing isotopic tools to better understand the alteration of materials used in the built cultural heritage. It is focused on the study of the alteration of limestone used in the facades of historic buildings subject to atmospheric polluted environment. Actually in the elevated parts of the buildings, water as rainfall (runoff or wet deposition) or in vapor form (condensation or dry deposition) is the main agent of alteration. Thus, the rock/water interactions need to be well understood to propose adapted solution to better preserve the buildings. To identify the water transfer within the porous limestone and locate the reaction preferential sites, two isotopic tracers (D and 18O) are used to monitor the alteration solution (D) and locate the zones containing the secondary phases (18O). The Saint-Maximin limestone used in many monuments in the suburbs of Paris (France) as a building and restoration stone has been specifically studied. Pristine materials, stones from monuments (monuments in the Paris area) and samples altered in laboratory constitute the analytical corpus to compare different stages of alteration. In a first step the stones are characterized at different scales to identify the alteration pattern (SEM-EDS, Raman microspectrometry, XRD, rugosimetry) and study the water transfers (X-ray tomography, mercury porosimetry, imbibition kinetics). The samples are then altered in the laboratory by realistic and controlled wet or dry deposition using isotopically labeled solutions to locate the reaction zones by SIMS. The multiscale characterization of the alteration pattern has allowed proposing alteration mechanisms linked to the properties of the stones and their location inside the building. Moreover, the location of the reactive zones inside the materials determined by the isotopic experiments helps examining the role of the evolution of porosity and formation of alteration products within the material

  1. Hydrogeology and results of injection tests at waste-injection test sites in Pinellas County, Florida

    USGS Publications Warehouse

    Hickey, John J.

    1982-01-01

    Potential benefits or hazards to freshwater resources could result from subsurface injection of treated wastewater. Recognizing this, the U.S. Geological Survey, in cooperation with Pinellas County and the city of St. Petersburg, undertook an evaluation of the hydrogeology and injection of wastewater at proposed test sites on the Pinellas peninsula. The injection sites are underlain by sedimentary rocks ranging in age from Cretaceous to Pleistocene. Lower Eocene carbonate rocks were penetrated to a maximum depth of 3,504 feet and were found to have relatively low water yields. The most permeable part of the investigated section was in rocks of middle Eocene age within the Floridan aquifer. At the injection sites, the Floridan aquifer was subdivided into four permeable zones and three semiconfining beds. The test injection zone is within the Avon Park Limestone, the most productive of the identified permeable zones, with a transmissivity of about 1,000,000 feet squared per day. Two semiconfining beds are above the injection zone in the Suwannee Limestone and Ocala Limestone and have vertical hydraulic conductivities estimated to range from about 0.1 to 1 foot per day where these beds do not contain clay. Limited fresh ground-water supplies exist in the Floridan aquifer within the Pinellas peninsula. At all test sites, chloride concentration in the injection zone ranged from 19,000 to 20,000 milligrams per liter. Injection tests ranging in duration from 3 to 91.1 days were run at three different sites. Pressure buildup occurred in permeable zones above and below the injection zone during these tests. Calculated pressure buildup in observation wells close to and at some distance from the test wells was typically less than 1 pound per square inch. Injection and formation water will probably move slowly through the semiconfining bed overlying the injection zone, and long-term injection tests will be needed to determine the effectiveness of these beds to retard flow. The

  2. Limestone: high-throughput candidate phenotype generation via tensor factorization.

    PubMed

    Ho, Joyce C; Ghosh, Joydeep; Steinhubl, Steve R; Stewart, Walter F; Denny, Joshua C; Malin, Bradley A; Sun, Jimeng

    2014-12-01

    The rapidly increasing availability of electronic health records (EHRs) from multiple heterogeneous sources has spearheaded the adoption of data-driven approaches for improved clinical research, decision making, prognosis, and patient management. Unfortunately, EHR data do not always directly and reliably map to medical concepts that clinical researchers need or use. Some recent studies have focused on EHR-derived phenotyping, which aims at mapping the EHR data to specific medical concepts; however, most of these approaches require labor intensive supervision from experienced clinical professionals. Furthermore, existing approaches are often disease-centric and specialized to the idiosyncrasies of the information technology and/or business practices of a single healthcare organization. In this paper, we propose Limestone, a nonnegative tensor factorization method to derive phenotype candidates with virtually no human supervision. Limestone represents the data source interactions naturally using tensors (a generalization of matrices). In particular, we investigate the interaction of diagnoses and medications among patients. The resulting tensor factors are reported as phenotype candidates that automatically reveal patient clusters on specific diagnoses and medications. Using the proposed method, multiple phenotypes can be identified simultaneously from data. We demonstrate the capability of Limestone on a cohort of 31,815 patient records from the Geisinger Health System. The dataset spans 7years of longitudinal patient records and was initially constructed for a heart failure onset prediction study. Our experiments demonstrate the robustness, stability, and the conciseness of Limestone-derived phenotypes. Our results show that using only 40 phenotypes, we can outperform the original 640 features (169 diagnosis categories and 471 medication types) to achieve an area under the receiver operator characteristic curve (AUC) of 0.720 (95% CI 0.715 to 0.725). Moreover, in

  3. Quarry Quest. A Field Trip Guide to the Indiana Limestone District, Monroe and Lawrence Counties, Indiana.

    ERIC Educational Resources Information Center

    Shewmaker, Sherman N.

    This guide provides information for planning a field trip to the Indiana Limestone District. This district, located in Monroe and Lawrence Counties, Indiana, is responsible for material that has dominated the building-limestone market in the United States for nearly a century. A few of the many well-known buildings using Indiana limestone are the…

  4. Types of permeability development in limestone aquifers in Britain

    NASA Astrophysics Data System (ADS)

    Worthington, S. R. H.

    2009-04-01

    Advances over the last forty years have resulted in a clear understanding of how dissolution processes in limestone rocks enhance aquifer permeability. Laboratory experiments on dissolution rates of calcite and dolomite have established that there is a precipitous drop in dissolution rates as chemical equilibrium is approached. These results have been incorporated into numerical models, simulating the effects of dissolution over time and showing that it occurs along the entire length of pathways through limestone aquifers. The pathways become enlarged and integrated over time, forming self-organized networks of channels (or solutionally-enlarged fractures or fissures) that typically have apertures in the millimetre to centimetre range. The networks discharge at point-located springs. Numerical models that simulate dissolutional enlargement of fractures in limestone aquifers have given many insights into the conditions that favour different styles of permeability enhancement. Two end-member channel network types may be distinguished, one with many channels of similar size and one where a small number of large channels conduct most of the flow. In the latter case the larger channels may be metres in diameter (i.e. caves). Numerical modelling has shown that the former type are favoured where there is densely fractured rock, high hydraulic gradients, and recharge water close to chemical saturation (c/ceq close to 1). The latter type are favoured where there is sparsely fractured rock, low hydraulic gradients, and low values of c/ceq. These two contrasting types of aquifer have no distinguishing names in the literature. It seems reasonable to define a karst aquifer as an aquifer with self-organized, high-permeability channel networks formed by positive feedback between dissolution and flow. In this case both these aquifer types are karst aquifers. Perhaps it would be appropriate to call the former "microkarstic" aquifers and the latter "macrokarstic" aquifers. The range

  5. Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E.

    2003-01-01

    Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO2 in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity = 1000 mg/l CaCO3). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to 6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). The ???30% of the residual grains in the pulsed flow reactor that are armored have thicker (50- to 100-??m), more aluminous coatings and lack the gypsum rind that develops in the constant flow experiment. Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface. ?? 2003 Elsevier Ltd. All rights reserved.

  6. Low temperature dry scrubbing reaction kinetics and mechanisms, Volume 1

    SciTech Connect

    Prudich, M.E.; Sampson, K.J.; Reddy, S.N.; Maldei, M.; Ben-Said, L. )

    1992-10-01

    Dry scrubbing that takes place after the air preheater (<350[degree]F) is the mode of operation that is of primary interest to this research project. At the relatively low temperatures that occur in this region of operation the rate of the gas-solid reaction that drives SO[sub 2] capture in the convective (800 to 1200[degree]F) and the combustion (1600 to 2400[degree]F) zones is too slow to be significant. The presence of significant amounts of either liquid-phase or vapor-phase water is required in order to mediate SO[sub 2] capture and to produce reasonable capture rates. A mathematical process model describing the cross-flow, moving-bed Limestone Emission Control (LEC) process has been formulated. This process model incorporates the resistance-in-series SO[sub 2] capture kinetic model described in the Project Year [number sign]1 final report. The kinetic model formulated during Project Year [number sign]1 pointed to limestone solubility and rate of solubilization as being key factors in determining the rate of SO[sub 2] capture in wetted limestone (LEC) scrubbing systems. In Project Year [number sign]2, limestone solubilities and rates of solubilization are being determined for a suite of Ohio limestones.

  7. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  8. Performance of portland limestone cements: Cements designed to be more sustainable that include up to 15% limestone addition

    NASA Astrophysics Data System (ADS)

    Barrett, Timothy J.

    In 2009, ASTM and AASHTO permitted the use of up to 5% interground limestone in ordinary portland cement (OPC) as a part of a change to ASTM C150/AASHTO M85. When this work was initiated a new proposal was being discussed that would enable up to 15% interground limestone cement to be considered in ASTM C595/AASHTO M234. This work served to provide rapid feedback to the state department of transportation and concrete industry for use in discussions regarding these specifications. Since the time this work was initiated, ASTM C595/AASHTO M234 was passed (2012c) and PLCs are now able to be specified, however they are still not widely used. The proposal for increasing the volume of limestone that would be permitted to be interground in cement is designed to enable more sustainable construction, which may significantly reduce the CO2 that is embodied in the built infrastructure while also extending the life of cement quarries. Research regarding the performance of cements with interground limestone has been conducted by the cement industry since these cements became widely used in Europe over three decades ago, however this work focuses on North American Portland Limestone Cements (PLCs) which are specifically designed to achieve similar performance as the OPCs they replace.This thesis presents a two-phase study in which the potential for application of cements containing limestone was assessed. The first phase of this study utilized a fundamental approach to determine whether cement with up to 15% of interground or blended limestone can be used as a direct substitute to ordinary portland cement. The second phase of the study assessed the concern of early age shrinkage and cracking potential when using PLCs, as these cements are typically ground finer than their OPC counterparts. For the first phase of the study, three commercially produced PLCs were obtained and compared to three commercially produced OPCs made from the same clinker. An additional cement was tested

  9. century drying

    NASA Astrophysics Data System (ADS)

    Cook, Benjamin I.; Smerdon, Jason E.; Seager, Richard; Coats, Sloan

    2014-11-01

    Global warming is expected to increase the frequency and intensity of droughts in the twenty-first century, but the relative contributions from changes in moisture supply (precipitation) versus evaporative demand (potential evapotranspiration; PET) have not been comprehensively assessed. Using output from a suite of general circulation model (GCM) simulations from phase 5 of the Coupled Model Intercomparison Project, projected twenty-first century drying and wetting trends are investigated using two offline indices of surface moisture balance: the Palmer Drought Severity Index (PDSI) and the Standardized Precipitation Evapotranspiration Index (SPEI). PDSI and SPEI projections using precipitation and Penman-Monteith based PET changes from the GCMs generally agree, showing robust cross-model drying in western North America, Central America, the Mediterranean, southern Africa, and the Amazon and robust wetting occurring in the Northern Hemisphere high latitudes and east Africa (PDSI only). The SPEI is more sensitive to PET changes than the PDSI, especially in arid regions such as the Sahara and Middle East. Regional drying and wetting patterns largely mirror the spatially heterogeneous response of precipitation in the models, although drying in the PDSI and SPEI calculations extends beyond the regions of reduced precipitation. This expansion of drying areas is attributed to globally widespread increases in PET, caused by increases in surface net radiation and the vapor pressure deficit. Increased PET not only intensifies drying in areas where precipitation is already reduced, it also drives areas into drought that would otherwise experience little drying or even wetting from precipitation trends alone. This PET amplification effect is largest in the Northern Hemisphere mid-latitudes, and is especially pronounced in western North America, Europe, and southeast China. Compared to PDSI projections using precipitation changes only, the projections incorporating both

  10. The effects of additive on limestone capturing sulfur during coal combustion

    SciTech Connect

    Chang, L.; Zhu, S.; Xie, K.; Liu, J.

    1998-12-31

    During high sulfur coal combustion, the desulfurization capacity of calcium-based sorbents has been investigated. The roles of additives in limestone were obvious and the capturing sulfur capacity of limestone containing additives is superior to that of only limestone under given reaction condition. The interaction mechanism of additive, limestone and SO{sub 2} was determined by DTA-TG and EA technology. These measurements showed that the reactions of limestone desulfurization primarily occurred at the first section of coal combustion, the active component is calcium carbonate and the reaction mechanism is not alike for additives existing or not.

  11. EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.

    USGS Publications Warehouse

    Mossotti, Victor G.; Lindsay, James R.; Hochella, Michael F.

    1987-01-01

    Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.

  12. Cement substitution by a combination of metakaolin and limestone

    SciTech Connect

    Antoni, M.; Rossen, J.; Martirena, F.; Scrivener, K.

    2012-12-15

    This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury intrusion porosimetry and isothermal calorimetry. We show that 45% of substitution by 30% of metakaolin and 15% of limestone gives better mechanical properties at 7 and 28 days than the 100% PC reference. Our results show that calcium carbonate reacts with alumina from the metakaolin, forming supplementary AFm phases and stabilizing ettringite. Using simple mass balance calculations derived from thermogravimetry results, we also present the thermodynamic simulation for the system, which agrees fairly well with the experimental observations. It is shown that gypsum addition should be carefully balanced when using calcined clays because it considerably influences the early age strength by controlling the very rapid reaction of aluminates.

  13. Preservation of York Minster historic limestone by hydrophobic surface coatings.

    PubMed

    Walker, Rachel A; Wilson, Karen; Lee, Adam F; Woodford, Julia; Grassian, Vicki H; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-01-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO(2) emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO(2)/H(2)O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation.

  14. Preservation of York Minster historic limestone by hydrophobic surface coatings.

    PubMed

    Walker, Rachel A; Wilson, Karen; Lee, Adam F; Woodford, Julia; Grassian, Vicki H; Baltrusaitis, Jonas; Rubasinghege, Gayan; Cibin, Giannantonio; Dent, Andrew

    2012-01-01

    Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO(2) emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO(2)/H(2)O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation. PMID:23198088

  15. Remanent magnetization of a Pliensbachian limestone sequence at Bakonycsernye (Hungary)

    NASA Astrophysics Data System (ADS)

    Márton, E.; Márton, P.; Heller, F.

    1980-06-01

    Remanent coercivity spectra derived from IRM acquisition curves and thermal demagnetization of the IRM indicate that magnetite, haematite and minor amounts of goethite determine the magnetic properties of the Pliensbachian limestones at Bakonycsernye. These limestones have been sampled at approximately 7-cm intervals along a 10-m stratigraphic section which covers the whole Pliensbachian stage (Lower Jurassic) without any recognizable break in sedimentation. The primary natural remanent magnetization (NRM) is carried by detrital particles of magnetite and haematite, but it is seriously overprinted by a normal magnetization which originates from secondary haematite with a wide range of blocking temperatures. This haematite is believed to have formed diagenetically during one of the Mesozoic periods of normal polarity. However, the reversal pattern obtained after NRM thermal demagnetization at temperatures ≥450°C is thought to be characteristic of the Pliensbachian stage.

  16. Injection molding ceramics to high green densities

    NASA Technical Reports Server (NTRS)

    Mangels, J. A.; Williams, R. M.

    1983-01-01

    The injection molding behavior of a concentrated suspension of Si powder in wax was studied. It was found that the injection molding behavior was a function of the processing techniques used to generate the powder. Dry ball-milled powders had the best molding behavior, while air classified and impact-milled powders demonstrated poorer injection moldability. The relative viscosity of these molding batches was studied as a function of powder properties: distribution shape, surface area, packing density, and particle morphology. The experimental behavior, in all cases, followed existing theories. The relative viscosity of an injection molding composition composed of dry ball-milled powders could be expressed using Farris' relation.

  17. Long-term calcination/carbonation cycling and thermal pretreatment for CO{sub 2} capture by limestone and dolomite

    SciTech Connect

    Zhongxiang Chen; Hoon Sub Song; Miguel Portillo; C. Jim Lim; John R. Grace; E.J. Anthony

    2009-03-15

    Capturing carbon dioxide is vital for the future of climate-friendly combustion, gasification, and steam-re-forming processes. Dry processes utilizing simple sorbents have great potential in this regard. Long-term calcination/carbonation cycling was carried out in an atmospheric-pressure thermogravimetric reactor. Although dolomite gave better capture than limestone for a limited number of cycles, the advantage declined over many cycles. Under some circumstances, decreasing the carbonation temperature increased the rate of reaction because of the interaction between equilibrium and kinetic factors. Limestone and dolomite, after being pretreated thermally at high temperatures (1000 or 1100{sup o}C), showed a substantial increase in calcium utilization over many calcination/carbonation cycles. Lengthening the pretreatment interval resulted in greater improvement. However, attrition was significantly greater for the pretreated sorbents. Greatly extending the duration of carbonation during one cycle was found to be capable of restoring the CO{sub 2} capture ability of sorbents to their original behavior, offering a possible means of countering the long-term degradation of calcium sorbents for dry capture of carbon dioxide. 12 refs., 12 figs., 2 tabs.

  18. Triptorelin Injection

    MedlinePlus

    ... response to triptorelin injection. Your blood sugar and glycosylated hemoglobin (HbA1c) should be checked regularly.Ask your pharmacist any questions you have about triptorelin injection.It is important for you to keep a written list of all of the prescription and ...

  19. Leuprolide Injection

    MedlinePlus

    ... response to leuprolide injection. Your blood sugar and glycosylated hemoglobin (HbA1c) should be checked regularly.Ask your pharmacist any questions you have about leuprolide injection.It is important for you to keep a written list of all of the prescription and ...

  20. National conference on agricultural limestone. Bulletin Y-166

    SciTech Connect

    Not Available

    1981-09-01

    Twenty-three papers were presented on various facets of the agricultural limestone (aglime) industry - from the quarry to the farmers. They are organized under the following section headings: introduction and overview; status of current use and need; agronomic situation; a total approach to marketing aglime, producing aglime; and a look to the future. Panel discussions were held on the topics, responding to the seasonal nature of aglime use and regional reviews of the status and opportunities for aglime use. (JGB)

  1. Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands

    USGS Publications Warehouse

    Hein, J.R.; Gray, S.C.; Richmond, B.M.; White, L.D.

    1992-01-01

    The primary reef framework is considered to have been deposited during several highstands of sea level. Following partial to local recrystallization of the limestone, a signle episode of dolomitization occurred. Both tidal and thermal pumping drove large quantities of seawater through the porous rocks and perhaps maintained a wide mixing zone. However, the isotopic, geochemical and petrographic data do not clearly indicate the extent of seawater mixing. -from Authors

  2. Time-Dependent Rock Failure in a Heterogeneous Limestone

    NASA Astrophysics Data System (ADS)

    Roth, K.; Kemeny, J.

    2015-12-01

    Time-dependent rock failure is an important aspect in the analysis of long-term rock stability for slopes, dam and bridge foundations, and underground storage facilities. An on-going project at the University of Arizona is using Kartchner Caverns in Benson, Arizona as a natural analog to study such failure by reconstructing the process of natural cave breakdown with subcritical crack growth modeling. Breakdown is thought to occur along joints through the time-dependent failure of rock bridges: sections of intact rock separating discontinuities in a rock mass. The Escabrosa limestone composing the caverns ranges from a more homogenous, even-grained texture to a more heterogeneous texture consisting of coarse-grained veins and solution cavities set in a fine-grained matrix. To determine if the veined regions are more susceptible to fracturing and act as the nuclei of rock bridge failure, fracture toughness tests were conducted for both textures. The subcritical crack growth parameters were calculated using the constant stress-rate method. Results indicate that the more heterogeneous limestone has a higher fracture strength, fracture toughness, and subcritical crack growth index n than the more homogeneous limestone. This is in agreement with previous studies which found that a more complex and heterogeneous microstructure produces a larger microcrack process zone, leading to higher fracture energies and lower susceptibility to subcritical crack growth. Thus, despite their solution cavities, the calcite veins do not localize failure or act as planes of weakness; instead, rock bridges fail through the more homogeneous limestone matrix.

  3. Musculoskeletal Injection

    PubMed Central

    Wittich, Christopher M.; Ficalora, Robert D.; Mason, Thomas G.; Beckman, Thomas J.

    2009-01-01

    Patients commonly present to primary care physicians with musculoskeletal symptoms. Clinicians certified in internal medicine must be knowledgeable about the diagnosis and management of musculoskeletal diseases, yet they often receive inadequate postgraduate training on this topic. The musculoskeletal problems most frequently encountered in our busy injection practice involve, in decreasing order, the knees, trochanteric bursae, and glenohumeral joints. This article reviews the clinical presentations of these problems. It also discusses musculoskeletal injections for these problems in terms of medications, indications, injection technique, and supporting evidence from the literature. Experience with joint injection and the pharmacological principles described in this article should allow primary care physicians to become comfortable and proficient with musculoskeletal injections. PMID:19720781

  4. Recovery and recycling of limestone in LEC flue gas desulfurization. Final report, third year

    SciTech Connect

    Gardner, N.C.; Boo, J.Y.

    1993-12-20

    A potentially attractive flue gas desulfurization method called Limestone Emission Control (LEC) is currently being investigated by Prudich at Ohio University. In this process, beds of 1/8 inch limestone gravel particles absorb sulfur dioxide from flue gas. This forms sulfite and sulfate salts which coat limestone, blinding the surface and limiting utilization to 20%. Favorable economics can be generating when the unreacted portion of the limestone is recovered by mechanical grinding. This project is a wet method for grinding and recovering the spent limestone from the LEC process, utilizing an impeller fluidizer, a new type of slurry processor. It consists of a cylindrical vessel with an impeller at one end. The impeller generates sufficient pressure head to serve as a slurry pump. It combines the operation of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry. The objectives of the first two years were to operate fluidizer in a batch mode to carry grinding experiments, and to determine the removal of the sulfur coatings from the limestone when operating the fluidizer in a continuous mode. The main thrusts of the third year were to complete the grinding data and coordinate the data with reactivity determinations of the recovered limestone. Direct measurement of power requirements, operation of single impeller fluidizer, grinding of surface deposits and other methods of removing surface deposits have also been investigated along with sorption characteristics of recovered limestone, microscopic examination of the limestone surface, and limestone attrition.

  5. Dry cell battery poisoning

    MedlinePlus

    Batteries - dry cell ... Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries ...

  6. Development of gypsum alteration on marble and limestone

    USGS Publications Warehouse

    McGee, E.S.

    1996-01-01

    Blackened alteration crusts of gypsum plus particulates that form on sheltered areas on marble and limestone buildings pose a challenge for rehabilitation and cleaning. Fresh marble and limestone samples exposed at monitored exposure sites present conditions of simple geometry and well-documented exposures but have short exposure histories (one to five years). The gypsum alteration crusts that develop on these samples provide insight into the early stages and rate of alteration crust formation. Alteration crusts from buildings give a longer, but less well known exposure history and present much more complex surfaces for gypsum accumulation. Integrated observations and measurements of alteration crusts from exposure samples and from buildings identify four factors that are important in the formation and development of alteration crusts on marble and limestone: (1) pollution levels, (2) exposure to rain or washing, (3) geometry of exposure of the stone surface, and (4) permeability of the stone. The combination of these factors contributes to both the distribution and the physical characteristics of the gypsum crusts which may affect cleaning decisions.

  7. Stratigraphy of the Upper Pleistocene Miami Limestone of Florida

    SciTech Connect

    Johnson, R.A.

    1993-03-01

    The upper Pleistocene Miami Limestone is probably the most stratigraphically-complex formation in the Cenozoic of Florida. The Miami overlies and vertically/laterally grades into the upper Pleistocene Ft. Thompson Formation to the west in southeast Palm Beach County (west of I-95); to the west in Broward County (west of the Turnpike); and to the north in south Broward County (along U.S. 27). The Miami overlies and very locally vertically grades into the Ft. Thompson in all of Dade County. The Miami overlies and vertically/laterally grades into the upper Pleistocene Anastasia Formation to the north and east in southeast Palm Beach County (east of I-95), and to the northeast in east Broward County (east of the Turnpike). The Miami laterally grades into the upper Pleistocene Key Largo Limestone to the southeast in extreme southeast Dade County, and overlies and locally vertically grades into the Key Largo in the Lower Keys, south Monroe County. The Miami unconformably overlies the Pliocene Tamiami Formation and pinches out to the west in northeast mainland Monroe and southeast Collier Counties, and also pinches out to the north in east-central Palm Beach County. In all areas, the Miami Limestone is either overlain unconformably by very discontinuous undifferentiated surficial sediments or forms land surface.

  8. Laboratory Investigations in Support of Dioxide-Limestone Sequestration in the Ocean

    SciTech Connect

    Dan Golomb; Eugene Barry; David Ryan; Stephen Pennell; Carl Lawton; Peter Swett; Devinder Arora; John Hannon; Michael Woods; Huishan Duan; Tom Lawlor

    2008-09-30

    Research under this Project has proven that liquid carbon dioxide can be emulsified in water by using very fine particles as emulsion stabilizers. Hydrophilic particles stabilize a CO{sub 2}-in-H{sub 2}O (C/W) emulsion; hydrophobic particles stabilize a H{sub 2}O-in-CO{sub 2} (W/C) emulsion. The C/W emulsion consists of tiny CO{sub 2} droplets coated with hydrophilic particles dispersed in water. The W/C emulsion consists of tiny H{sub 2}O droplets coated with hydrophobic particles dispersed in liquid carbon dioxide. The coated droplets are called globules. The emulsions could be used for deep ocean sequestration of CO{sub 2}. Liquid CO{sub 2} is sparsely soluble in water, and is less dense than seawater. If neat, liquid CO{sub 2} were injected in the deep ocean, it is likely that the dispersed CO{sub 2} droplets would buoy upward and flash into vapor before the droplets dissolve in seawater. The resulting vapor bubbles would re-emerge into the atmosphere. On the other hand, the emulsion is denser than seawater, hence the emulsion plume would sink toward greater depth from the injection point. For ocean sequestration a C/W emulsion appears to be most practical using limestone (CaCO{sub 3}) particles of a few to ten ?m diameter as stabilizing agents. A mix of one volume of liquid CO{sub 2} with two volumes of H{sub 2}O, plus 0.5 weight of pulverized limestone per weight of liquid CO{sub 2} forms a stable emulsion with density 1087 kg m{sup -3}. Ambient seawater at 500 m depth has a density of approximately 1026 kg m{sup -3}, so the emulsion plume would sink by gravity while entraining ambient seawater till density equilibrium is reached. Limestone is abundant world-wide, and is relatively cheap. Furthermore, upon disintegration of the emulsion the CaCO{sub 3} particles would partially buffer the carbonic acid that forms when CO{sub 2} dissolves in seawater, alleviating some of the concerns of discharging CO{sub 2} in the deep ocean. Laboratory experiments showed

  9. 21 CFR 522.2424 - Sodium thiamylal for injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... § 522.2424 Sodium thiamylal for injection. (a) Specifications. The drug is a sterile dry powder. It is reconstituted aseptically with sterile distilled water, water for injection, or sodium chloride injection, to a... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium thiamylal for injection. 522.2424...

  10. 21 CFR 522.2424 - Sodium thiamylal for injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... § 522.2424 Sodium thiamylal for injection. (a) Specifications. The drug is a sterile dry powder. It is reconstituted aseptically with sterile distilled water, water for injection, or sodium chloride injection, to a... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium thiamylal for injection. 522.2424...

  11. Thermo-poroelastic response of an argillaceous limestone

    NASA Astrophysics Data System (ADS)

    Selvadurai, Patrick; Najari, Meysam

    2016-04-01

    Argillaceous limestones are now being considered by many countries that intend to develop deep geologic storage facilities for siting both high-level and intermediate- to low-level nuclear fuel wastes. In deep geologic settings for high level nuclear wastes, the heating due to radioactive decay is transmitted through an engineered barrier, which consists of the waste container and an engineered geologic barrier, which consists of an encapsulating compacted bentonite. The heat transfer process therefore leads to heating of the rock mass where the temperature of the rock is substantially lower than the surface temperature of the waste container. This permits the use of mathematical theories of poroelastic media where phase transformations, involving conversion of water to a vapour form are absent. While the thermo-poroelastic responses of geologic media such as granite and porous tuff have been investigated in the literature, the investigation of thermo-poroelastic responses of argillaceous limestones is relatively new. Argillaceous limestones are considered to be suitable candidates for siting deep geologic repositories owing to the ability to accommodate stress states with generation of severe defects that can influence their transmissivity characteristics. Also the clay fraction in such rocks can contribute to long term healing type phenomena, which is a considerable advantage. This research presents the results of a laboratory investigation and computational modelling of the same that examines the applicability of the theory of thermo-poroelasticity, which extend Biot's classical theory of poroelasticity to include uncoupled heat conduction. The experimental configuration involves the boundary heating of a cylinder of the Cobourg Limestone from southern Ontario, Canada. The cylinder measuring 150 mm in diameter and 278 mm in length contains an axisymmetric fluid-filled cylindrical cavity measuring 26 mm in diameter and 139 mm in length. Thermo-poroelastic effects

  12. Structural characterization of a karstified limestone formation using GPR

    NASA Astrophysics Data System (ADS)

    Rousset, D.; Sénéchal, G.; Gaffet, S.

    2009-12-01

    The Laboratoire Souterrain à Bas Bruit (LSBB) at Rustrel - Pays d'Apt, France, is an Inter-disciplinary Underground Science and Technology Laboratory buried in a karstified limestone formation. A multidisciplinary program focused on water circulation monitoring is presently performed inside the tunnels. This program comprises the investigation of faults, fractures, karstification and stratigraphy ofthe limestone massif using GPR. We present the main results obtained from these data. The tunnel has been dug in lower cretaceous limestone which is characterized by a low clay content, high electrical resistivity which results in generally very low attenuation of electro-magnetic waves. 90% of the tunnels floor are made of concrete whereas other are made of bare limestone. This experimental site offers a unique opportunity of perfoming measurements within an unweathered limestone massif. The whole 3km long tunnel has been investigated using single offset shielded 250 MHz antennas in May 2009. Processing includes : DC and very low frequency removal, amplitude compensation preserving lateral variations, migration and time to depth conversion. When necessary predictive deconvolution has been applied to remove ringing effects. These data sets are characterized by good signal to noise ratio and a signal penetration down to 18 meters. These data allow us to accurately map the stratigraphy of the surrounding rocks across the concrete walls of the tunnel. Some 20 m deep vertical wells have been drilled inside the tunnel through observed reflectors. This is a strong validation of the GPR images. The estimated resolution is centimetric to decimetric and matches the required geologic accuracy. The GPR data set allows to extend previous geological results in depth, particularly in the concrete coated parts of the tunnel where conventional geological surveying is impossible. Thanks to the processing which preserves lateral amplitude variations, GPR sections exhibit prominent

  13. Isavuconazonium Injection

    MedlinePlus

    ... overdose may include the following: headache dizziness pain, burning, or tingling in the hands or feet drowsiness difficulty focusing change in sense of taste dry mouth numbness in the mouth diarrhea vomiting sudden reddening ...

  14. Mipomersen Injection

    MedlinePlus

    ... the refrigerator at least 30 minutes before you plan to inject it to allow the medication to ... supplements, and herbal products you are taking or plan to take. Be sure to mention the medications ...

  15. Ibritumomab Injection

    MedlinePlus

    ... is in a class of medications called monoclonal antibodies with radioisotopes. It works by attaching to cancer ... you receive ibritumomab injection, your body may develop antibodies (substances in the blood that help the immune ...

  16. Romiplostim Injection

    MedlinePlus

    ... including other medications or surgery to remove the spleen. Romiplostim injection should not be used to treat ... tell your doctor if you have had your spleen removed.tell your doctor if you are pregnant, ...

  17. Golimumab Injection

    MedlinePlus

    ... and swelling and scales on the skin). ulcerative colitis (a condition which causes swelling and sores in ... you are using golimumab injection to treat ulcerative colitis (a condition which causes swelling and sores in ...

  18. Colistimethate Injection

    MedlinePlus

    ... antibiotics. It works by killing bacteria that cause infection.Antibiotics such as colistimethate injection will not work for colds, flu, or other viral infections. Taking or using antibiotics when they are not needed increases your risk ...

  19. Doxycycline Injection

    MedlinePlus

    ... antibiotics. It works by killing bacteria that cause infections.Antibiotics such as doxycycline injection will not work for colds, flu, or other viral infections. Taking or using antibiotics when they are not needed increases your risk ...

  20. Tigecycline Injection

    MedlinePlus

    ... in a person who was not in the hospital), skin infections, and infections of the abdomen (area between the ... that developed in people who were in a hospital or foot infections in people who have diabetes. Tigecycline injection is ...

  1. Thiotepa Injection

    MedlinePlus

    ... reproductive organs where eggs are formed), breast, and bladder cancer. It is also used to treat malignant effusions ( ... how you respond to thiotepa.When used for bladder cancer, thiotepa is infused (injected slowly) into your bladder ...

  2. Ferumoxytol Injection

    MedlinePlus

    Ferumoxytol injection is used to treat iron-deficiency anemia (a lower than normal number of red blood cells due to too little iron) in adults with chronic kidney disease (damage to the kidneys which may worsen over ...

  3. Daclizumab Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS; a disease in which ... injections. Before you use daclizumab yourself the first time, read the written instructions that come with it. ...

  4. Olanzapine Injection

    MedlinePlus

    Olanzapine extended-release injection is used to treat schizophrenia (a mental illness that causes disturbed or unusual ... treat episodes of agitation in people who have schizophrenia or in people who have bipolar I disorder ( ...

  5. Risperidone Injection

    MedlinePlus

    ... release (long-acting) injection is used to treat schizophrenia (a mental illness that causes disturbed or unusual ... do not already have diabetes. If you have schizophrenia, you are more likely to develop diabetes than ...

  6. Acetaminophen Injection

    MedlinePlus

    ... injection is also used in combination with opioid (narcotic) medications to relieve moderate to severe pain. Acetaminophen is in a class of medications called analgesics (pain relievers) and antipyretics (fever reducers). It works by changing ...

  7. Panitumumab Injection

    MedlinePlus

    ... as a solution (liquid) to be given by infusion (injected into a vein). It is usually given ... doctor or nurse in a doctor's office or infusion center. Panitumumab is usually given once every 2 ...

  8. Dolasetron Injection

    MedlinePlus

    Dolasetron injection is used to prevent and treat nausea and vomiting that may occur after surgery. Dolasetron ... should not be used to prevent or treat nausea and vomiting in people receiving cancer chemotherapy medications. ...

  9. Teduglutide Injection

    MedlinePlus

    ... syndrome in people who need additional nutrition or fluids from intravenous (IV) therapy. Teduglutide injection is in ... analogs. It works by improving the absorption of fluids and nutrients in the intestines.

  10. Ampicillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to ampicillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, ...

  11. Nafcillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to nafcillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  12. Oxacillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to oxacillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  13. Lacosamide Injection

    MedlinePlus

    ... drowsiness uncontrollable shaking of a part of the body problems with coordination, balance, or walking weakness itching redness, irritation, pain, or discomfort at the injection spot Some side effects can be serious. If you experience any of ...

  14. Epinephrine Injection

    MedlinePlus

    ... emergency medical treatment to treat life-threatening allergic reactions caused by insect bites or stings, foods, medications, ... at the first sign of a serious allergic reaction.Use epinephrine injection exactly as directed; do not ...

  15. Vedolizumab Injection

    MedlinePlus

    ... injection may cause serious allergic reactions during an infusion and for several hours afterward. A doctor or ... of the following symptoms during or after your infusion: rash; itching; swelling of the face, eyes, mouth, ...

  16. Mitoxantrone Injection

    MedlinePlus

    ... medications to relieve pain in people with advanced prostate cancer who did not respond to other medications. Mitoxantrone ... doses). When mitoxantrone injection is used to treat prostate cancer, it is usually given once every 21 days. ...

  17. Bendamustine Injection

    MedlinePlus

    ... leukemia (CLL; a type of cancer of the white blood cells). Bendamustine injection is also used to treat a ... NHL: cancer that begins in a type of white blood cell that normally fights infection) that is slow spreading, ...

  18. Moxifloxacin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as pneumonia; ; and , skin, and abdominal (stomach ... antibiotics called fluoroquinolones. It works by killing the bacteria that cause infections.Antibiotics such as moxifloxacin injection ...

  19. Ceftazidime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftazidime injection will not work ...

  20. Gentamicin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as gentamicin injection will not work ...

  1. Meropenem Injection

    MedlinePlus

    ... skin and abdominal (stomach area) infections caused by bacteria and meningitis (infection of the membranes that surround ... of medications called antibiotics. It works by killing bacteria that cause infection.Antibiotics such as meropenem injection ...

  2. Tobramycin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as tobramycin injection will not work ...

  3. Ceftaroline Injection

    MedlinePlus

    ... infections and pneumonia (lung infection) caused by certain bacteria. Ceftaroline is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftaroline injection will not work ...

  4. Telavancin Injection

    MedlinePlus

    ... serious skin infections caused by certain types of bacteria. Telavancin injection is in a class of medications ... antibiotics. It works by stopping the growth of bacteria. Antibiotics will not work for colds, flu, or ...

  5. Daptomycin Injection

    MedlinePlus

    ... blood infections or serious skin infections caused by bacteria. Daptomycin injection is in a class of medications called cyclic lipopeptide antibiotics. It works by killing bacteria. Antibiotics will not work for treating colds, flu, ...

  6. Aztreonam Injection

    MedlinePlus

    ... to treat certain infections that are caused by bacteria, including respiratory tract (including pneumonia and bronchitis), urinary ... abdominal (stomach area) infections, that are caused by bacteria. Aztreonam injection also may be used before, during, ...

  7. Cefepime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia, and skin, urinary tract, and kidney ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefepime injection will not work ...

  8. Amikacin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as amikacin injection will not work ...

  9. Ertapenem Injection

    MedlinePlus

    ... abdominal (stomach area) infections, that are caused by bacteria. It is also used for the prevention of ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as ertapenem injection will not work ...

  10. Ciprofloxacin Injection

    MedlinePlus

    ... Ciprofloxacin injection is also sometimes used to treat cat scratch disease (an infection that may develop after a person is bitten or scratched by a cat), Legionnaires' disease (type of lung infection), and infections of the ...

  11. Ganciclovir Injection

    MedlinePlus

    Ganciclovir injection is used to treat cytomegalovirus (CMV) retinitis (eye infection that can cause blindness) in people whose immune system is not working normally, including those people who have ...

  12. Levofloxacin Injection

    MedlinePlus

    ... infections. Levofloxacin injection is also used to prevent anthrax (a serious infection that may be spread on ... in people who may have been exposed to anthrax germs in the air and treat and prevent ...

  13. Ibandronate Injection

    MedlinePlus

    ... Ibandronate is in a class of medications called bisphosphonates. It works by preventing bone breakdown and increasing ... while receiving this medication.Being treated with a bisphosphonate medication such as ibandronate injection for osteoporosis may ...

  14. Fondaparinux Injection

    MedlinePlus

    ... the leg), which can lead to pulmonary embolism (PE; a blood clot in the lung), in people ... with warfarin (Coumadin, Jantoven) to treat DVT or PE. Fondaparinux injection is in a class of medications ...

  15. Pertuzumab Injection

    MedlinePlus

    ... docetaxel (Taxotere) to treat a certain type of breast cancer that has spread to other parts of the body. Pertuzumab injection is in a class of medications called monoclonal antibodies. It works by stopping the growth of cancer ...

  16. Octreotide Injection

    MedlinePlus

    ... injection is used to decrease the amount of growth hormone (a natural substance) produced by people with acromegaly (condition in which the body produces too much growth hormone, causing enlargement of the hands, feet, and facial ...

  17. Haloperidol Injection

    MedlinePlus

    ... release injection are used to treat schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of ... medications); medications for anxiety, depression, irritable bowel disease, mental illness, motion sickness, Parkinson's disease, seizures, ulcers, or urinary ...

  18. Sumatriptan Injection

    MedlinePlus

    ... accompanied by nausea and sensitivity to sound and light). Sumatriptan injection is also used to treat the ... children. Store it at room temperature, away from light, excess heat, and moisture (not in the bathroom). ...

  19. Topotecan Injection

    MedlinePlus

    ... organs where eggs are formed) and small cell lung cancer (a type of cancer that begins in the ... topotecan injection is used to treat ovarian or lung cancer, it is usually given once a day for ...

  20. Pembrolizumab Injection

    MedlinePlus

    ... treat a certain type of non-small-cell lung cancer that has spread to nearby tissues or to ... successfully with other medications for non-small-cell lung cancer. Pembrolizumab injection is in a class of medications ...

  1. Oritavancin Injection

    MedlinePlus

    ... for at least 5 days after receiving oritavancin injection.tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking ...

  2. Cefuroxime Injection

    MedlinePlus

    ... pneumonia and other lower respiratory tract (lung) infections; meningitis (infection of the membranes that surround the brain ... hearing loss, if you are being treated for meningitis Cefuroxime injection may cause other side effects. Call ...

  3. Alirocumab Injection

    MedlinePlus

    ... further decrease the amount of low-density lipoprotein (LDL) cholesterol ('bad cholesterol') in the blood. Alirocumab injection is ... antibodies. It works by blocking the production of LDL cholesterol in the body to decrease the amount of ...

  4. Secukinumab Injection

    MedlinePlus

    ... to see if you need to receive any vaccinations. It is important to have all vaccines appropriate ... treatment with secukinumab injection. Do not have any vaccinations during your treatment without talking to your doctor. ...

  5. Biotin- and Glycoprotein-Coated Microspheres as Surrogates for Studying Filtration Removal of Cryptosporidium parvum in a Granular Limestone Aquifer Medium.

    PubMed

    Stevenson, M E; Blaschke, A P; Toze, S; Sidhu, J P S; Ahmed, W; van Driezum, I H; Sommer, R; Kirschner, A K T; Cervero-Aragó, S; Farnleitner, A H; Pang, L

    2015-07-01

    Members of the genus Cryptosporidium are waterborne protozoa of great health concern. Many studies have attempted to find appropriate surrogates for assessing Cryptosporidium filtration removal in porous media. In this study, we evaluated the filtration of Cryptosporidium parvum in granular limestone medium by the use of biotin- and glycoprotein-coated carboxylated polystyrene microspheres (CPMs) as surrogates. Column experiments were carried out with core material taken from a managed aquifer recharge site in Adelaide, Australia. For the experiments with injection of a single type of particle, we observed the total removal of the oocysts and glycoprotein-coated CPMs, a 4.6- to 6.3-log10 reduction of biotin-coated CPMs, and a 2.6-log10 reduction of unmodified CPMs. When two different types of particles were simultaneously injected, glycoprotein-coated CPMs showed a 5.3-log10 reduction, while the uncoated CPMs displayed a 3.7-log10 reduction, probably due to particle-particle interactions. Our results confirm that glycoprotein-coated CPMs are the most accurate surrogates for C. parvum; biotin-coated CPMs are slightly more conservative, while unmodified CPMs are markedly overly conservative for predicting C. parvum removal in granular limestone medium. The total removal of C. parvum observed in our study suggests that granular limestone medium is very effective for the filtration removal of C. parvum and could potentially be used for the pretreatment of drinking water and aquifer storage recovery of recycled water.

  6. Biotin- and Glycoprotein-Coated Microspheres as Surrogates for Studying Filtration Removal of Cryptosporidium parvum in a Granular Limestone Aquifer Medium

    PubMed Central

    Blaschke, A. P.; Toze, S.; Sidhu, J. P. S.; Ahmed, W.; van Driezum, I. H.; Sommer, R.; Kirschner, A. K. T.; Cervero-Aragó, S.; Farnleitner, A. H.; Pang, L.

    2015-01-01

    Members of the genus Cryptosporidium are waterborne protozoa of great health concern. Many studies have attempted to find appropriate surrogates for assessing Cryptosporidium filtration removal in porous media. In this study, we evaluated the filtration of Cryptosporidium parvum in granular limestone medium by the use of biotin- and glycoprotein-coated carboxylated polystyrene microspheres (CPMs) as surrogates. Column experiments were carried out with core material taken from a managed aquifer recharge site in Adelaide, Australia. For the experiments with injection of a single type of particle, we observed the total removal of the oocysts and glycoprotein-coated CPMs, a 4.6- to 6.3-log10 reduction of biotin-coated CPMs, and a 2.6-log10 reduction of unmodified CPMs. When two different types of particles were simultaneously injected, glycoprotein-coated CPMs showed a 5.3-log10 reduction, while the uncoated CPMs displayed a 3.7-log10 reduction, probably due to particle-particle interactions. Our results confirm that glycoprotein-coated CPMs are the most accurate surrogates for C. parvum; biotin-coated CPMs are slightly more conservative, while unmodified CPMs are markedly overly conservative for predicting C. parvum removal in granular limestone medium. The total removal of C. parvum observed in our study suggests that granular limestone medium is very effective for the filtration removal of C. parvum and could potentially be used for the pretreatment of drinking water and aquifer storage recovery of recycled water. PMID:25888174

  7. Weight losses of marble and limestone briquettes exposed to outdoor environment in the eastern United States: Results of exposure 1988--1992

    SciTech Connect

    Reimann, K.J.

    1995-04-01

    Monitoring continued on weight changes in marble and limestone briquettes exposed to the outdoor environment at sites in the eastern US. This report presents data for the exposure period 1988--1992 and summarizes results for the entire period from 1984. Since 1989, only three exposure sites have remained active, but briquettes from preexposed material were added at those sites. A linear relationship was found between cumulative gravimetric losses and exposure period. These losses resulted in an average recession rate of 11 to 21 {micro}m/yr for marble and 21 to 45 {micro}m/yr for limestone. The recession rates are site-dependent and can be described with respect to rain depth and other atmospheric conditions, as evidenced by the very low rates at the Ohio site on the movable rack, dry regime. Weight monitoring is continuing in a planned 10-year program.

  8. Sodium-limestone double alkali flue gas desulfurization method

    SciTech Connect

    Wang, K.H.; Biolchini, R.J.; Legatski, L.K.

    1983-10-18

    A flue gas desulfurization method is disclosed for efficiently removing sulfur oxides from a gas stream with an aqueous sodium sulfite- and sodium bisulfite-containing absorption solution, in which absorber effluent solution at a pH of 5.8 to 6.6 and having an active sodium concentration of from 0.5 M to 0.9 M is regenerated with sufficient ground limestone to yield a treated solution with a higher pH of from 6.3 to 7.0 and whose bisulfite concentration is reduced by from 35 to 70%

  9. Penetration into limestone targets with ogive-nose steel projectiles

    SciTech Connect

    Frew, D.J.; Green, M.L.; Forrestal, M.J.; Hanchak, S.J.

    1996-12-01

    We conducted depth of penetration experiments into limestone targets with 3.0 caliber-radius-head, 4340 Rc 45 steel projectiles. Powder guns launched two projectiles with length-to-diameter ratios of ten to striking velocities between 0.4 and 1.5 km/s. Projectiles had diameters and masses of 12.7 mm, 0. 117 kg and 25.4 mm, 0.610 kg. Based on data sets with these two projectile scales, we proposed an empirical penetration equation that described the target by its density and an empirical strength constant determined from penetration depth versus striking velocity data.

  10. Absorption spectra of crystalline limestones experimentally deformed or tectonised

    NASA Astrophysics Data System (ADS)

    Cervelle, B.; ChayéD'Albissin, M.; Gouet, G.; Visocekas, R.

    1982-11-01

    Diffuse-reflectance spectra have been measured for a series of samples of Carrara marble experimentally deformed under different cylindrical stress ( P = 0, 100, 250, 500, 980 bars). The creation of point defects that results has been shown up classically by irradiation with β rays (40 krads), thus producing a typical blue coloration linked with the formation of colour centres. The diffuse-reflectance spectra, measured on powders with a microscope-spectrometer in the visible range (400-800 nm), allow the determination of the absorption spectra by means of the Kubelka-Munk function. These absorption spectra have been measured for each of the deformed samples, as well as for different fractions of a very deformed specimen subsequently heated at temperatures between 100 and 500° C for a fixed time. In the same way, tectonised crystalline limestones, of various origins, were studied without any other treatment than the irradiation with β rays. From this study the following preliminary conclusions have been drawn: (1) The absorption spectrum of an undeformed but merely irradiated specimen of crystalline limestone is practically monotonous, but in the deformed specimens a broad band of absorption appears, having a maximum at 620 nm with several shoulders, the chief of which is at 520 nm. (2) This absorption band shows the existence of colour centres, the density of which can be estimated relatively by means of the chromaticity coordinates x and y of the C.I.E. obtained from the diffuse-reflectance spectra (C.I.E. = Commission Internationale de l'Éclairage). (3) An overgrinding of calcite generates defects that have the same spectra as those produced during the experimental deformation. Consequently, in obtaining the powders of grain size 50-80 μm needed for the diffuse spectrometry, great care must be exercised. (4) For a given confining pressure, the defect density is proportional to the deformation rate. (5) One can calibrate the effect of the annealing of

  11. Elucidation of denitrification mechanism in karstic Ryukyu limestone aquifer

    NASA Astrophysics Data System (ADS)

    Hijikawa, K.

    2014-12-01

    Nitrate (NO3-) concentrations in public water supplies have risen above acceptable levels in many areas of the world including Japan, largely as a result of contamination by human and animal waste and overuse of fertilizers. A previous study has characterized nitrate concentrations in groundwater in this area is a higher than the upper value (44mgL-1) of environmental quality criteria on one hands. On the other hand, there exists points where the concentration of nitric acid is not detected, which suggests the possibility of denitrification. During early 2000, a new analytical procedure for nitrate isotopic measurement, termed the "denitrifier method", was established. With the development of the nitrate isotope tracer method, much research has been reported detailing sources of groundwater nitrate and denitrification mechanisms. This study presents a pilot case study (in the southern part of Okinawa Main Island, Japan, where Ryukyu limestone is extensively distributed) using the combined stable isotope ratios of major elements (C, N and S) as net recorders of the biogeochemical reactions with the aim of elucidation of denitrification mechanism in Ryukyu limestone aquifer. As a result, significant decreases in nitrate concentrations due to denitrification were observed in groundwater at some locations, which induced increases in isotope ratios up to 59.7‰ for δ15NNO3. These points of groundwater were located above the cutoff wall of the underground dam and near the fault. It is considered that the residence time of the groundwater is longer than the other points at these denitrification points, and that reduction condition tends to be formed in the groundwater. However, the rapid rise of the groundwater level due to rainfall is likely to occur in the Ryukyu limestone aquifer, where the ground water was found to have changed dynamically from the reduction condition to the oxidation condition which a denitrification (has not occured)does not occur. Moreover, the

  12. Bio-deposition of a calcium carbonate layer on degraded limestone by Bacillus species.

    PubMed

    Dick, Jan; De Windt, Wim; De Graef, Bernard; Saveyn, Hans; Van der Meeren, Paul; De Belie, Nele; Verstraete, Willy

    2006-08-01

    To obtain a restoring and protective calcite layer on degraded limestone, five different strains of the Bacillus sphaericus group and one strain of Bacillus lentus were tested for their ureolytic driven calcium carbonate precipitation. Although all the Bacillus strains were capable of depositing calcium carbonate, differences occurred in the amount of precipitated calcium carbonate on agar plate colonies. Seven parameters involved in the process were examined: calcite deposition on limestone cubes, pH increase, urea degrading capacity, extracellular polymeric substances (EPS)-production, biofilm formation, zeta-potential and deposition of dense crystal layers. The strain selection for optimal deposition of a dense CaCO(3) layer on limestone, was based on decrease in water absorption rate by treated limestone. Not all of the bacterial strains were effective in the restoration of deteriorated Euville limestone. The best calcite precipitating strains were characterised by high ureolytic efficiency, homogeneous calcite deposition on limestone cubes and a very negative zeta-potential. PMID:16491305

  13. Effect of water treatment chemicals on limestone/sulfur dioxide reaction in flue gas desulfurization systems

    SciTech Connect

    Dille, E.R.; Gaikwad, R.P.

    1994-12-31

    A simple laboratory test has been developed which simulates the reaction between limestone/water and sulfur dioxide in flue gas desulfurization systems. By adding various chemicals, in differing concentrations, to the limestone/water mixture, the quantitative impact on the sulfur dioxide/limestone reaction can be qualified and quantified. This paper will present the impact of several water treatment chemicals on the reaction of limestone and sulfur dioxide. An attempt has been made to predict the effect through mathematical correlations. All of the additive chemicals tend to decrease the rate of dissolution of limestone to various degrees. Some of the chemicals retard crystal growth thus adversely impacting solids separation in the thickener. The physical appearance of the crystal growth retarded limestone absorber slurry approaches a colloidal suspension.

  14. Bio-deposition of a calcium carbonate layer on degraded limestone by Bacillus species.

    PubMed

    Dick, Jan; De Windt, Wim; De Graef, Bernard; Saveyn, Hans; Van der Meeren, Paul; De Belie, Nele; Verstraete, Willy

    2006-08-01

    To obtain a restoring and protective calcite layer on degraded limestone, five different strains of the Bacillus sphaericus group and one strain of Bacillus lentus were tested for their ureolytic driven calcium carbonate precipitation. Although all the Bacillus strains were capable of depositing calcium carbonate, differences occurred in the amount of precipitated calcium carbonate on agar plate colonies. Seven parameters involved in the process were examined: calcite deposition on limestone cubes, pH increase, urea degrading capacity, extracellular polymeric substances (EPS)-production, biofilm formation, zeta-potential and deposition of dense crystal layers. The strain selection for optimal deposition of a dense CaCO(3) layer on limestone, was based on decrease in water absorption rate by treated limestone. Not all of the bacterial strains were effective in the restoration of deteriorated Euville limestone. The best calcite precipitating strains were characterised by high ureolytic efficiency, homogeneous calcite deposition on limestone cubes and a very negative zeta-potential.

  15. Hydrologic and Geochemical Evaluation of Aquifer Storage Recovery in the Santee Limestone/Black Mingo Aquifer, Charleston, South Carolina, 1998-2002

    USGS Publications Warehouse

    Petkewich, Matthew D.; Parkhurst, David L.; Conlon, Kevin J.; Campbell, Bruce G.; Mirecki, June E.

    2004-01-01

    The hydrologic and geochemical effects of aquifer storage recovery were evaluated to determine the potential for supplying the city of Charleston, South Carolina, with large quantities of potable water during emergencies, such as earthquakes, hurricanes, or hard freezes. An aquifer storage recovery system, including a production well and three observation wells, was installed at a site located on the Charleston peninsula. The focus of this study was the 23.2-meter thick Tertiary-age carbonate and sand aquifer of the Santee Limestone and the Black Mingo Group, the northernmost equivalent of the Floridan aquifer system. Four cycles of injection, storage, and recovery were conducted between October 1999 and February 2002. Each cycle consisted of injecting between 6.90 and 7.19 million liters of water for storage periods of 1, 3, or 6 months. The volume of recovered water that did not exceed the U.S. Environmental Protection Agency secondary standard for chloride (250 milligrams per liter) varied from 1.48 to 2.46 million liters, which is equivalent to 21 and 34 percent of the total volume injected for the individual tests. Aquifer storage recovery testing occurred within two productive zones of the brackish Santee Limestone/Black Mingo aquifer. The individual productive zones were determined to be approximately 2 to 4 meters thick, based on borehole geophysical logs, electromagnetic flow-meter testing, and specific-conductance profiles collected within the observation wells. A transmissivity and storage coefficient of 37 meters squared per day and 3 x 10-5, respectively, were determined for the Santee Limestone/Black Mingo aquifer. Water-quality and sediment samples collected during this investigation documented baseline aquifer and injected water quality, aquifer matrix composition, and changes in injected/aquifer water quality during injection, storage, and recovery. A total of 193 water-quality samples were collected and analyzed for physical properties, major and

  16. Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

    SciTech Connect

    Hayes, J.; Bertschinger, V. ); Aley, T. )

    1993-04-01

    Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyes were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.

  17. Analysis of medieval limestone sculpture from southwestern France and the Paris Basin by NAA

    SciTech Connect

    Holmes, L.; Harbottle, G.

    1994-12-31

    Compositional characterization of limestone from sources known to medieval craftsmen and from the monuments they built can be used in conjunction with stylistic and iconographic criteria to infer geographic origin of sculptures that have lost their histories. Limestone from 47 quarrying locations in France and from numerous medieval monuments have been subjected to neutron activation analysis (NAA) to form the nucleus of the Brookhaven Limestone Database. Even though the method and techniques of NAA are well established, this paper briefly summarizes the parameters and experimental conditions useful for determining those concentration variables for which limestone from different sources exhibits significant and reproducible differences.

  18. Limestones of western Newfoundland that magnetized before Devonian folding but after Middle Ordovician lithification

    SciTech Connect

    Hodych, J.P. )

    1989-01-01

    A positive fold test and a negative conglomerate test help determine when and how stable remanence was acquired in the Middle Ordovician Table Head Group limestones of the Port au Port Peninsula of Newfoundland. The limestones magnetized after lithification and incorporation as clasts into a Middle Ordovician breccia. Hence, the limestones do not carry a detrital or other primary remanence despite their very low conodont color alteration index. The remanence may be thermoviscous or diagenetic and was acquired before Devonian folding. This suggests the need for caution in interpreting paleomagnetic results from other early Paleozoic limestones whose remanence resides in magnetite of blocking temperature lower than 400C.

  19. Hydrogeology of the gray limestone aquifer in southern Florida

    USGS Publications Warehouse

    Reese, Ronald S.; Cunningham, Kevin J.

    2000-01-01

    Results from 35 new test coreholes and aquifer-test, water-level, and water-quality data were combined with existing hydrogeologic data to define the extent, thickness, hydraulic properties, and degree of confinement of the gray limestone aquifer in southern Florida. This aquifer, previously known to be present only in southeastern Florida (Miami-Dade, Broward, and Palm Beach Counties) below, and to the west of, the Biscayne aquifer, extends over most of central-south Florida, including eastern and central Collier County and southern Hendry County; it is the same as the lower Tamiami aquifer to the north, and it becomes the water-table aquifer and the upper limestone part of the lower Tamiami aquifer to the west. The aquifer generally is composed of gray, shelly, lightly to moderately cemented limestone with abundant shell fragments or carbonate sand, abundant skeletal moldic porosity, and minor quartz sand. The gray limestone aquifer comprises the Ochopee Limestone of the Tamiami Formation, and, in some areas, the uppermost permeable part of an unnamed formation principally composed of quartz sand. Underlying the unnamed formation is the Peace River Formation of the upper Hawthorn Group, the top of which is the base of the surficial aquifer system. Overlying the aquifer and providing confinement in much of the area is the Pinecrest Sand Member of the Tamiami Formation. The thickness of the aquifer is comparatively uniform, generally ranging from 30 to 100 feet. The unnamed formation part of the aquifer is up to 20 feet thick. The Ochopee Limestone accumulated in a carbonate ramp depositional system and contains a heterozoan carbonate-particle association. The principal rock types of the aquifer are pelecypod lime rudstones and floatstones and permeable quartz sands and sandstones. The pore types are mainly intergrain and separate vug (skeletal-moldic) pore spaces. The rock fabric and associated primary and secondary pore spaces combine to form a dual diffuse

  20. Rare earths in the Leadville Limestone and its marble derivates

    USGS Publications Warehouse

    Jarvis, J.C.; Wildeman, T.R.; Banks, N.G.

    1975-01-01

    Samples of unaltered and metamorphosed Leadville Limestone (Mississippian, Colorado) were analyzed by neutron activation for ten rare-earth elements (REE). The total abundance of the REE in the least-altered limestone is 4-12 ppm, and their distribution patterns are believed to be dominated by the carbonate minerals. The abundances of the REE in the marbles and their sedimentary precursors are comparable, but the distribution patterns are not. Eu is enriched over the other REE in the marbles, and stratigraphically upward in the formation (samples located progressively further from the heat source), the light REE become less enriched relative to the heavy REE. The Eu anomaly is attributed to its ability, unique among the REE, to change from the 3+ to 2+ oxidation state. Whether this results in preferential mobilization of the other REE or whether this reflects the composition of the pore fluid during metamorphism is unknown. Stratigraphically selective depletion of the heavy REE may be attributed to more competition for the REE between fluid and carbonate minerals in the lower strata relative to the upper strata. This competition could have been caused by changes in the temperature of the pore fluid or to the greater resistance to solution of the dolomite in the lower parts of the formation than the calcite in the upper parts. ?? 1975.

  1. Reactivation properties of four long-term sulfated limestones

    SciTech Connect

    Yinghai Wu; Edward J. Anthony; Lufei Jia

    2006-12-15

    Four Canadian limestones - Cadomin, Havelock, Kelly Rock, and Graymont - were investigated for their reactivation properties after long-term sulfation. Each limestone was initially sulfated with 1% SO{sub 2} at 850{sup o}C in a tube furnace for a relatively long time (about 16 h), to achieve an effectively maximally sulfated sample. The samples were subsequently hydrated with liquid water and steam at various conditions to reactivate the unreacted CaO. The hydrated samples were resulfated in a thermogravimetric analyzer for 90 min to evaluate the effect of hydration on the resulfation step. All four samples were significantly reactivated by steam hydration, which was much more effective than was hydration with liquid water, and the overall calcium utilization increased to 80-90% after reactivation, compared to 25-45% typical before reactivation. A scanning electron microscope was used to analyze Cadomin and Havelock samples, and both were uniformly sulfated before hydration. This work indicated that the uniformly sulfated samples could be reactivated given suitable hydration conditions.

  2. Treatment of mining acidic leachates with indigenous limestone, Zimapan Mexico.

    PubMed

    Labastida, I; Armienta, M A; Lara-Castro, R H; Aguayo, A; Cruz, O; Ceniceros, N

    2013-11-15

    An experimental study to evaluate the potential of using indigenous limestones in a passive system to treat acid mine drainage, at a mining zone of Mexico was carried out. Chemical and mineralogical characteristics of four types of native rocks (KIT1, KIT2, KSS, QZ) showed distinct CaCO3 contents. Synthetic aqueous leachates from an old tailings impoundment had a pH of 2.18, 34 mg/L As, 705 mg/L Fetotal, and 3975 mg/L SO4(2-). To evaluate dissolution behavior of rocks, kinetic batch experiments with an acid Fe-rich solution were performed. Decaying kinetic constants adjusting H(+) concentration to a first order exponential process were: KIT1 (k = 2.89), KIT2 (k = 0.89) and KSS (k = 0.47). Infrared spectrum and XRD of precipitates showed schwertmannite formation. To determine As and heavy metals (Fe, Cd, Zn, Al) removal from the synthetic leachates, batch experiments using KIT1 were developed. Arsenic decreased from 34.00 mg/L to 0.04 mg/L, Fe and Al were totally removed, and concentrations of Zn and Cd decreased 88% and 91% respectively. Analyses by IR and SEM-EDS indicate that co-precipitation with Fe-Hydroxides formed upon leachate interaction with limestone is the main As removal process. Chamosite, identified by XRD may participate in the removal of Al, SiO2 and a fraction of Fe.

  3. Dust resuspension characteristics over several quarries of limestone

    NASA Astrophysics Data System (ADS)

    Mandija, F.; Vila, F.

    2012-04-01

    One of the most important physical properties of the soil on ground surface is its ability to be involved on dust resuspension influenced by mechanical processes. Dust resuspension process depends on several factors. Some of them are soil properties, soil moisture, vegetation, paved/unpaved state, as well as the type of mechanical process, like wind, traffic, etc. Taking into consideration all these soil properties and environmental factors we determine dust resuspension rate. In this study we have conducted measurements on aerosol size distributions over several dust types, on different meteorological conditions. Aerosol size distributions measured on our measurements belong to sub-micrometric and micrometric size ranges. This is the size range which is the most influenced by resuspension processes. Places where there are carried out the experimental measurements are limestone quarries. Experimental procedure was conducted under fair weather meteorological conditions. Overall results of our measurements give valuable information about the ability of these soils to be involved on dust resuspension processes. The comparison of the concentrations of particulate matter over investigated areas indicates the contributions of different soil properties on dust resuspension process. In short, this study helps also on the estimation of air pollution on the areas with different soil types. These results let to estimate the real contribution of the activities carried on limestone quarries on aerosol number concentrations.

  4. Characterizing and modelling 'ghost-rock' weathered limestones

    NASA Astrophysics Data System (ADS)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  5. Treatment of mining acidic leachates with indigenous limestone, Zimapan Mexico.

    PubMed

    Labastida, I; Armienta, M A; Lara-Castro, R H; Aguayo, A; Cruz, O; Ceniceros, N

    2013-11-15

    An experimental study to evaluate the potential of using indigenous limestones in a passive system to treat acid mine drainage, at a mining zone of Mexico was carried out. Chemical and mineralogical characteristics of four types of native rocks (KIT1, KIT2, KSS, QZ) showed distinct CaCO3 contents. Synthetic aqueous leachates from an old tailings impoundment had a pH of 2.18, 34 mg/L As, 705 mg/L Fetotal, and 3975 mg/L SO4(2-). To evaluate dissolution behavior of rocks, kinetic batch experiments with an acid Fe-rich solution were performed. Decaying kinetic constants adjusting H(+) concentration to a first order exponential process were: KIT1 (k = 2.89), KIT2 (k = 0.89) and KSS (k = 0.47). Infrared spectrum and XRD of precipitates showed schwertmannite formation. To determine As and heavy metals (Fe, Cd, Zn, Al) removal from the synthetic leachates, batch experiments using KIT1 were developed. Arsenic decreased from 34.00 mg/L to 0.04 mg/L, Fe and Al were totally removed, and concentrations of Zn and Cd decreased 88% and 91% respectively. Analyses by IR and SEM-EDS indicate that co-precipitation with Fe-Hydroxides formed upon leachate interaction with limestone is the main As removal process. Chamosite, identified by XRD may participate in the removal of Al, SiO2 and a fraction of Fe. PMID:22819958

  6. Bird Species Diversity in the Padawan Limestone Area, Sarawak

    PubMed Central

    Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd; Koon, Lim Chan; Rahman, Mustafa Abdul

    2011-01-01

    Bird surveys were conducted in the Padawan Limestone Area for seven days at each of two study sites, Giam and Danu, from August to December 2008. The purpose of the study was to compare the area’s bird species richness and abundance of bird species in other limestone areas and in other forest types. The study also compared the species richness and relative abundance of birds in undisturbed and disturbed areas at both study sites. Twenty mist nets were deployed for 12 hours daily. During this study period, direct observations of birds were also made. In all, 80 species from 34 families were recorded at both sites. At Giam, 120 birds were mist-netted. These birds represented 31 species from 16 families. The direct observations at Giam recorded 13 species from 11 families. In the undisturbed area, 21 species from 13 families were mist-netted, whereas in the disturbed area, 21 species from 10 families were mist-netted. In Danu, a total of 48 birds, representing 25 species from 12 families, were mist-netted. The observations at Danu recorded 34 species from 19 families. Twelve species from 7 families were mist-netted in the undisturbed area, whereas 18 species from 11 families were mist-netted in the disturbed area. Statistical analysis showed that the species diversity index differed significantly between undisturbed and disturbed areas. PMID:24575218

  7. Colmenar limestone as a resource for built heritage

    NASA Astrophysics Data System (ADS)

    Fort, Rafael; Álvarez de Buergo, Mónica; Varas-Muriel, MªJosé; Mercedes Pérez-Monserrat, Elena

    2013-04-01

    The Colmenar stone (or Colmenar limestone) has been used in the construction of significant builidings of the Central area of Spain, such as the Royal Palace of Aranjuez (16th -18th centuries) or the Royal Palace of Madrid (18th century). Nowadays this building stone is still widely used, both for new construction and restoration works, as well as for the indoor ornamentation of emblematic buildings such as the Royal Theater of Madrid (20th century). There are many quarries from where this stone was exploited, being the most prestigious ones those located in Colmenar de Oreja, at 50 km Southeast the city of Madrid. The high quality of the stone in these quarries, its whiteness and pureness, made this locality the most relevant in these stonés extractive activities, concentrating the most relevant exploitations and providing the stone the denomination of the municipality (Colmenar). It was an underground mining extraction until the 20th century in order to reach the highest quality level of the mine, the so called "Banco Gordo" (Thick Bank). Generically known as moorland limestone, this rock belongs to the fluvial-lacustrine carbonates of the Upper Miocene Unit of the Tertiary Madrid's Basin. Its tonality mainly ranges from white to cream and even light grey. Under a petrographic point of view, this limestone is constituted by 40% of bioclasts (characea, ostracods and gasteropods), 20-30% of micritic matrix and 30-40% of sparitic cement. Therefore, it can be classified as a biomicrite/biosparite limestone or as a bioclastic packstone. Some particularities of these limestones regarding their appearance are related to some karstic processes they underwent linked to some dissolution phenomena during the Pliocene. All of this resulted on an abundance of cavities with terra rossa fillings, a non-soluble clayey residue, iron enriched, which is the responsible for the reddish and pinkish color that the Colmenar stone sometimes shows. These petrographic characteristics

  8. Drying Thermoplastics

    NASA Technical Reports Server (NTRS)

    1976-01-01

    In searching for an improved method of removing water from polyester type resins without damaging the materials, Conair Inc. turned to the NASA Center at the University of Pittsburgh for assistance. Taking an organized, thorough look at existing technology before beginning research has helped many companies save significant time and money. They searched the NASA and other computerized files for microwave drying of thermoplastics. About 300 relevant citations were retrieved - eight of which were identified as directly applicable to the problem. Company estimates it saved a minimum of a full year in compiling research results assembled by the information center.

  9. Eculizumab Injection

    MedlinePlus

    ... which too many red blood cells are broken down in the body, so there are not enough healthy cells to bring oxygen to all parts of the body). Eculizumab injection is also used to treat atypical hemolytic uremic syndrome (aHUS; an inherited condition in which small blood ...

  10. Fluconazole Injection

    MedlinePlus

    ... injection is used to treat fungal infections, including yeast infections of the mouth, throat, esophagus (tube leading from the mouth to the stomach), abdomen (area between the chest and waist), lungs, blood, and ... to prevent yeast infections in patients who are likely to become infected ...

  11. Tositumomab Injection

    MedlinePlus

    ... has not improved or that had improved after treatment with other medications, but later returned. Tositumomab injection is in a class of medications called monoclonal antibodies with radioisotopes. It works by attaching to cancer cells and releasing radiation to damage the cancer ...

  12. Lanreotide Injection

    MedlinePlus

    Lanreotide injection is used to treat people with acromegaly (condition in which the body produces too much growth hormone, causing enlargement of the hands, feet, and facial features; joint pain; and other symptoms) who have not successfully, or cannot be treated ...

  13. Eribulin Injection

    MedlinePlus

    ... tests to check your body's response to eribulin injection.It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring ...

  14. Pegaptanib Injection

    MedlinePlus

    ... to 7 days after you receive each pegaptanib injection.It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring ...

  15. Pedogenic calcretes within fracture systems and beddings in Neoproterozoic limestones of the Irecê Basin, northeastern Brazil

    NASA Astrophysics Data System (ADS)

    Borges, S. V. F.; Balsamo, F.; Vieira, M. M.; Iacumin, P.; Srivastava, N. K.; Storti, F.; Bezerra, F. H. R.

    2016-07-01

    Calcretes or caliches are continental limestones developed by surficial weathering process that takes place mostly in arid and semi-arid regions. In the Irecê Basin, northeastern Brazil, in addition to the regular occurrence of pedogenic calcretes, a peculiar type of structurally controlled calcretes occurs on Neoproterozoic limestones. These peculiar calcretes developed near the surface and occur (1) between layers, (2) inside fractures and (3) within major thrust faults. Fieldwork on selected outcrops was integrated with petrographic, mineralogic, geochemical, density and mercury intrusion porosity analyses to constrain the environment of formation and their petrophysical properties. The results revealed that this type of calcrete is the product of multiepisodic events of dissolution and precipitation occurring during the wet and dry seasons in the region along fractures and beddings. Based on the petrophysical results, we suggest that these calcretes may have an important role in the migration of fluids through the impermeable host carbonate rock and that they act as a conduit for fluid flow, as revealed by their high porosity (mean value = 26%) and remarkable pore connectivity.

  16. Effect of the specimen length on ultrasonic P-wave velocity in some volcanic rocks and limestones

    NASA Astrophysics Data System (ADS)

    Karaman, Kadir; Kaya, Ayberk; Kesimal, Ayhan

    2015-12-01

    Ultrasonic P-wave velocity (UPV) is commonly used in different fields such as civil, mining, geotechnical, and rock engineering. One of the significant parameters which affect the UPV of rock materials is likely to be the length of test cores although it is not mentioned in the literature. In this study, in order to explore the influence of the specimen length on the UPV, rock samples were collected from eight different locations in Turkey. The NX-sized core specimens having different length of 50, 75, 100, 125, and 150 mm were prepared. Before the analyses, rocks were divided into two groups in terms of their geological origins such as volcanic and chemical sedimentary (limestone) rocks. The UPV tests were carried out under dry and saturated conditions for each 200 core specimens. By evaluating the test results, it was shown that the length of the specimens significantly affects the UPV values. Based on the regression analyses, a method was developed to determine the threshold specimen length of studied rocks. Fluctuations in UPVdry and UPVsat values were generally observed for cores smaller than the threshold specimen length. In this study, the threshold specimen length was determined as 79 mm for volcanic rocks and 109 mm for limestones.

  17. Analyses of NOx and wet depositions at Mühleggerkböpfl, North Tyrolean Limestone Alps.

    PubMed

    Smidt, Stefan

    2002-01-01

    The intensive investigation site 'Mühleggerkopfl' in the North Tyrolean Limestone Alps can be classified as a clean-air area site. The mean concentrations of NOx are far below the effect-related limit value of the WHO (30 microg NOx m(-3)). The gravitational depositions in the open field (bulk deposition) ranged from 10.8 to 14.7 kg N ha(-1) a(-1) (throughfall: 11.3 to 12.3 kg N ha(-1) a(-1)) in the measuring years 1998 to 2000. Compared to these data, depositions in other forested areas of the Austrian Alps amounted to up to 30 kg N ha(-1) a(-1). The gravitational depositions (bulk deposition) alone--without considering dry and occult deposition slightly exceeded the lower limit of Critical Loads for coniferous and deciduous forests (>10 kg N ha(-1) a(-1)), but were below the Critical Loads for calcareous forests (15-20 kg N ha(-1) a(-1)).

  18. Crystallographic transformation of limestone during calcination under CO2.

    PubMed

    Valverde, Jose Manuel; Medina, Santiago

    2015-09-14

    The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressure and high temperature. In situ X-ray diffraction (XRD) has been employed in this work to gain further insight into the crystallographic transformation that takes place during the calcination of limestone under CO2, at partial pressures (P) close to the equilibrium pressure (Peq) and at high temperature. Calcination under these conditions becomes extremely slow. The in situ XRD analysis presented here suggests the presence of an intermediate metastable CaO* phase stemming from the parent CaCO3 structure. According to the reaction mechanism proposed elsewhere, the exothermicity of the CaO* → CaO transformation and high values of P/Peq inhibit the nucleation of CaO at high temperatures. The wt% of CaO* remains at a relatively high level during slow calcination. Two diverse stages have been identified in the evolution of CaO crystallite size, L. Initially, L increases with CaCO3 conversion, following a logarithmic law. Slow calcination allows the crystallite size to grow up from a few nanometers at nucleation up to around 100 nm near the end of conversion. Otherwise, quick calcination at relatively lower CO2 concentrations limits CaO crystallite growth. Once calcination reaches an advanced state, the presence of CaO* drops to zero and the rate of increase of the CaO crystallite size is significantly hindered. Arguably, the first stage in CaO crystallite growth is driven by aggregation of the metastable CaO* nanocrystals, due to surface attractive forces, whereas the second one is consistent with sintering of the aggregated CaO crystals, and persists with time after full

  19. Crystallographic transformation of limestone during calcination under CO2.

    PubMed

    Valverde, Jose Manuel; Medina, Santiago

    2015-09-14

    The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressure and high temperature. In situ X-ray diffraction (XRD) has been employed in this work to gain further insight into the crystallographic transformation that takes place during the calcination of limestone under CO2, at partial pressures (P) close to the equilibrium pressure (Peq) and at high temperature. Calcination under these conditions becomes extremely slow. The in situ XRD analysis presented here suggests the presence of an intermediate metastable CaO* phase stemming from the parent CaCO3 structure. According to the reaction mechanism proposed elsewhere, the exothermicity of the CaO* → CaO transformation and high values of P/Peq inhibit the nucleation of CaO at high temperatures. The wt% of CaO* remains at a relatively high level during slow calcination. Two diverse stages have been identified in the evolution of CaO crystallite size, L. Initially, L increases with CaCO3 conversion, following a logarithmic law. Slow calcination allows the crystallite size to grow up from a few nanometers at nucleation up to around 100 nm near the end of conversion. Otherwise, quick calcination at relatively lower CO2 concentrations limits CaO crystallite growth. Once calcination reaches an advanced state, the presence of CaO* drops to zero and the rate of increase of the CaO crystallite size is significantly hindered. Arguably, the first stage in CaO crystallite growth is driven by aggregation of the metastable CaO* nanocrystals, due to surface attractive forces, whereas the second one is consistent with sintering of the aggregated CaO crystals, and persists with time after full

  20. Dry Mouth or Xerostomia

    MedlinePlus

    ... or Xerostomia Request Permissions Print to PDF Dry Mouth or Xerostomia Approved by the Cancer.Net Editorial ... a dry mouth. Signs and symptoms of dry mouth The signs and symptoms of dry mouth include ...

  1. DEMONSTRATION OF SORBENT INJECTION TECHNOLOGY ON A WALL-FIRED UTILITY BOILER (EDGEWATER LIMB DEMONSTRATION)

    EPA Science Inventory

    The report gives results of the full-scale demonstration of Limestone Injection Multistage Burner (LIMB) technology on the coal-fired, 105 MW, Unit 4 boiler at Ohio Edison's Edgewater Station. eveloped as a technology aimed at moderate levels of sulfur dioxide (SO2) and nitrogen ...

  2. DEMONSTRATION OF SORBENT INJECTION TECHNOLOGY ON A TANGENTIALLY COAL-FIRED UTILITY BOILER (YORKTOWN LIMB DEMONSTRATION)

    EPA Science Inventory

    The report summarizes activities conducted and results achieved in an EPA-sponsored program to demonstrate Limestone Injection Multistage Burner (LIMB) technology on a tangentially fired coal-burning utility boiler, Virginia Power's 180-MWe Yorktown Unit No. 2. his successfully d...

  3. 76 FR 35396 - Black Hills National Forest, Mystic Ranger District, South Dakota, Section 30 Limestone Mining...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... Mining Project AGENCY: Forest Service, USDA. ACTION: Corrected Notice of intent to prepare an... the purpose of mining for chemical grade limestone within mining claims on National Forest System land... publication dates. A Notice of Availability for the Section 30 Limestone Mining Project Draft EIS...

  4. Adsorption and desorption of phosphate on limestone in experiments simulating seawater intrusion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The absorption and desorption of phosphorus on a large block of limestone was investigated using deionized water (DIW) and seawater. The limestone had a high affinity to adsorb phosphorus in DIW. Phosphate adsorption was significantly less in seawater, and more phosphorus was desorbed in the seawate...

  5. OPTIMIZATION OF A PULSED LIMESTONE BED REACTOR AT THE ARGO TUNNEL IN IDAHO SPRINGS, COLORADO

    EPA Science Inventory

    Acid Mine Drainage (AMD) is an unintended consequence of coal and metal mining that adversely affects thousands of miles of streams both in the eastern and western regions of the U.S. A novel AMD treatment process based on limestone based on limestone neutralization has been dev...

  6. STEAM ENHANCED REMEDIATION RESEARCH FOR DNAPL IN FRACTURED ROCK, LORING AIR FORCE BASE, LIMESTONE, MAINE

    EPA Science Inventory

    This report details a research project on Steam Enhanced Remediation (SER) for the recovery of volatile organic compounds from fractured limestone that was carried out at the Quarry at the former Loring Air Force Base in Limestone, Maine. This project was carried out by USEPA, Ma...

  7. Stratigraphy and depositional history of the West Franklin Limestone (Pennsylvanian) in the southernmost part of the Illinois Basin, western Kentucky

    SciTech Connect

    King, N.R. . Dept. of Geosciences)

    1994-04-01

    The West Franklin Limestone in the subsurface of Webster and Union Counties, Kentucky includes 7.5--18m of strata deposited during portions of four depositional cycles in the latest Desmoinesian and earliest Missourian (Pennsylvanian). These cycles began with marine flooding and deposition of limestone, followed by progradation of siliciclastics in three of the four cycles, and ended with emergence. The basal West Franklin is micritic limestone (0.5--3m) that rests on rooted mudstone. Overlying the limestone are siliciclastics (1.5--7m) dominated by red and green claystone that is rooted at the top. Next is a middle limestone zone that includes either a paleokarsted micritic limestone, or a thin bioclastic micritic limestone bed associated with phosphatic shale and locally a second bioclastic micritic limestone. Above that is another siliciclastic interval (4--9m) capped by rooted mudstone and locally a thin coal. The overlying micritic limestone (1.5--2.5m) marks the top of the West Franklin. Depositional events included: (1) marine flooding of an emergent shelf producing the basal limestone; (2) progradation of siliciclastics followed by emergence and paleosol development; (3) marine flooding producing a second limestone; (4) emergence and karstification of erosional remnants of the second limestone; (5) renewed marine flooding depositing shell hash'' limestones and phosphatic shale; (6) progradation of siliciclastics culminating in emergency; and (7) marine flooding producing the upper limestone. Thus, two flooding-emergence cycles are represented by the middle limestone zone. The second, locally-developed shell-hash'' limestone in the middle zone was deposited during the regressive phase of a depositional cycle. All of the other limestones were deposited during transgression.

  8. Hydrogeologic data for the South Cross Bayou test injection site, Pinellas County, Florida

    USGS Publications Warehouse

    Hickey, John J.

    1978-01-01

    One exploratory hole, a test injection well, and nine monitor wells were constructed at the South Cross Bayou test-injection site between January 1973 and October 1975. At the test site, the first 125 feet below land surface is predominantly limestone and clay; from 125 to 3,280 feet it is mostly limestone and dolomite. Gypsum is also present below 1,260 feet. Wells within about a 1-mi radius of the test injection site were sampled and analyzed to provide water-quality background data prior to anticipated long-term injection at the test site. Locations of the wells sampled are shown, reported construction data are given, and the chemical analyses of water from these wells are tabulated. Chloride concentration of water from the wells near the test site ranged between 9.8 to 290 mg/L. Reported depth of these wells ranged from 25 to 302 ft. (Woodard-USGS)

  9. Thermal strengthening of limestone: monument preservation during fire

    NASA Astrophysics Data System (ADS)

    Heap, Michael; Lavallee, Yan; Benson, Philip; Hess, Kai-Uwe; Dingwell, Donald

    2010-05-01

    The use of natural rocks in the construction of buildings and monuments predates the use of commercially engineered materials such as concrete. Such building material can be subject to elevated temperatures in the misfortunate event of a fire. In civil engineering, it is generally appreciated that the strength of rock is decreased when it is or has been exposed to elevated temperatures. This is due the formation of thermal microcracks, a result of the thermal expansion mismatch between different minerals in the rock. Even today, fire is by no means an uncommon occurrence and approximately one historic building is lost to fire in the European Union every day (COST C17 2001). A large number of historically significant buildings and monuments are constructed from carbonate material. However, could the paradigm of thermal weakening of limestone construction material be in part, a paradox? We report new findings on the thermal strengthening of the Solnhofen limestone (Solnhofen, Germany), a carbonate rock traditionally used in construction of building and statues in central Europe. Two types of deformation experiments were performed to investigate: (1) the strength of samples at elevated temperatures (i.e. during fire) and (2) the strength of samples at room temperature after heat-treatment (i.e. after fire). During experimentation, microcracking was monitored by the output of acoustic emissions (AE). Thermo-gravimetric (TG) analysis was also undertaken to measure the mass loss during heating. For the experiments ‘during fire', samples were heated to temperatures of 25°, 200°, 400°, 500°, 600°, 650° and 800°C at a controlled rate of 5°C/min and deformed until failure in a uniaxial press at a constant strain rate of 10-5 s-1. For the experiments ‘after fire', samples were heat-treated to each 100°C increment up to 800°C, they were then cooled at the same rate and their strength tested at room temperature. The mechanical data demonstrate that, during fire

  10. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    SciTech Connect

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-03-15

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  11. Lithology and strontium distribution of De Queen limestone at main Highland Gypsum Quarry, Highland, Arkansas

    SciTech Connect

    Slaughter, T.A.; Ledger, E.B.; Sartin, A.A.

    1987-09-01

    The De Queen Limestone (Comanchean, Cretaceous) in the main Highland Gypsum quarry at Highland, Arkansas, consists of gypsum, limestone, and clastic sediments deposited along the landward margin of a broad, restricted, shallow lagoon. It grades downdip into the Ferry Lake Anhydrite. Gypsum, in the form of satin spar, selenite, and alabaster, is abundant in the lower part of the section. Limestones ranging from lime mudstones to grainstones contain fossil mollusks, ostracods, serpulid worm tubes, and foraminifera. The gypsum and limestone lithologies are interbedded with claystones and shales. Strontium concentration was determined on about 100 samples by x-ray fluorescence spectrometry (XRF) and was found to be controlled by diagenesis, not deposition. Strontium concentrations in the gypsum are likely controlled by the rate of recrystallization of secondary anhydrite. Levels of strontium in the limestones reflect the amount of celestite cement. The strontium content of the clastic beds correlates with the amount of strontium-rich microcrystals of strontianite, celestite, barite, and witherite.

  12. EPRI High-Sulfur Test Center: Wet flue gas desulfurization baseline limestone tests

    SciTech Connect

    Gray, S.M.; Burke, J.M.

    1990-10-01

    This report presents the results of the Baseline Limestone Test Program conducted at Electric Power Research Institute's (EPRI) High Sulfur Test Center (HSTC). The objective of this program was to characterize wet limestone FGD system performance as a function of basic FGD design and operating variables using the pilot system at the HSTC. The results from this program will be useful in optimizing existing wet limestone FGD systems, and will provide the foundation for more specific research to be conducted at the HSTC. The design and operating variables that were investigated include: inlet SO{sub 2} concentration, liquid-to-gas ratio, slurry pH and density, dissolved calcium concentration, reaction tank volume, limestone grind, and in-situ forced oxidation. Results illustrate the effect of these variables on SO{sub 2} removal efficiency, limestone utilization, sulfite oxidation, and the waste solids properties. 20 refs., 58 figs., 19 tabs.

  13. Toxicity of acid mine pit lake water remediated with limestone and phosphorus

    SciTech Connect

    Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y.

    2009-11-15

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  14. Shallow-water limestones within the Paleogene forearc basin of California: Unique paleogeographic indicators

    SciTech Connect

    Whidden, K.J.; Bottjer, D.J.; Lund, S.P. . Dept. of Geological Sciences)

    1992-01-01

    A number of shallow-water limestones have recently been documented in late Mesozoic/Paleogene forearc strata of the Cordilleran continental arc. These limestones occur on two different tectonic blocks which were both developed within the forearc basin and subsequently moved relative to one another due to oblique convergence since Late Cretaceous time. Faunal evidence suggests that these limestones were deposited within the photic zone, at shelfal depths. Each limestone represents part or all of the basal Paleogene sequence; they are intercalated with or overlain by deeper-water strata. One region of outcrops in the western Santa Monica Mountains is latest Paleocene in age, while the other region, in the eastern Santa Ynez Mountains and Wheeler Gorge area, is early Eocene in age. These shallow-water limestones may be used as paleogeographic indicators, as they represent relative topographic highs within the basin. The microplate tectonic reconstruction of Hornafius (1985) suggests that the limestones occur on opposite sides of a north-south trending trough within the overall forearc basin. The Paleocene limestones, which occur along the eastern margin of the trough, are intercalated with marine shales and may represent small fluctuations in relative sea level and/or sediment supply on a topographic high. The Eocene limestones, which occur along the western side of the trough, are always the basal Paleogene unit deposited on tilted Cretaceous strata or Franciscan rocks and overlain by deeper-water shales. The occurrence of Franciscan as basement for limestone deposition implies localized tectonic uplift within the forearc. Each of these limestones probably represents initiation of a single period of relative sea level rise, as the basal shallow-water carbonates were eventually overwhelmed by deeper-water shales. Thus two episodes of carbonate deposition allow for the delineation of two topographic highs within the Paleogene forearc basin.

  15. Low temperature dry scrubbing reaction kinetics and mechanisms, Volume 2. Final report, September 1, 1991--August 31, 1992

    SciTech Connect

    Prudich, M.E.; Sampson, K.J.; Reddy, S.N.; Maldei, M.; Ben-Said, L.

    1992-10-01

    A novel wet/dry desulfurization post-Furnace process (ETS` Limestone Emission control (LEC) process) for SO{sub 2} removal has been described by Prudich et al.(1988). In this process hot flue gases are contacted with a bed of quarry-sized (1/4in. to 1/32in.) wet limestone granules. This thesis represents the development of a second generation model of ETS` LEC process. The first generation model developed by Prudich et al.(1988) the use of a fixed limestone bed. The work done on this has been well documented by Appell (1989) and Visneski (1991) process under consideration for this thesis involves a continuously moving limestone bed. The moving bed simplifies the process flowsheet and facilitates limestone reactivation. The moving-bed LEC process involves the use of a cross-flow pattern with the flue gas flowing horizontally across the limestone bed at speeds of around 1 to 2 feet per second and the limestone moving vertically downward through the LEC reactor at speeds of around 1 to 15 feet per hour. The primary parameters considered in the mathematical modeling of the moving-bed LEC process are inlet sulfur dioxide concentration, inlet gas-phase water concentration, inlet flue gas and limestone temperatures and water spray addition rate over the bed. For solution of the process, mass and energy balance equations derived as a function of the positions of the flue gas limestone are solved using a predictor-corrector method. The Adams-Bashforth (modified Euler`s) method is used with a second order corrector.

  16. Dolomitization and over-dolomitization in the Vajont limestone (Dolomiti Bellunesi, Italy) controlled by Mesozoic normal faults: a microstructural and diagenesis study

    NASA Astrophysics Data System (ADS)

    Cortinovis, Silvia; Swennen, Rudy; Bistacchi, Andrea

    2015-04-01

    The Vajont Gorge (Dolomiti Bellunesi, Italy) provides spectacular outcrops of Jurassic limestones (Vajont Limestone Formation) in which Mesozoic faults and fracture corridors are continuously exposed. Some of these faults acted as conduits for Mg-enriched hydrothermal fluids resulting in structurally-controlled dolomitization of the limestone. The dolomitization resulted in several dolomite bodies (100-200 m thick and several hundreds of meters along fault strike) that are particularly interesting as reservoir analogues for hydrocarbon, CO2, or water-bearing systems. The dolomitization process occurred after deposition and compaction of the oolitic limestone (dolomitization post-dates a dissolution event that affected the internal parts of the oolites), but before the Alpine contractional deformation. In fact, the meso-structural data collected in the Vajont Gorge allowed the reconstruction of a 3D model showing that the circulation of the dolomitizing fluids into the limestone host rock, but also the late stage of porosity reduction (strong pore filling due to over-dolomitization) were controlled by normal faults and fracture corridors interpreted as Pre-Alpine (Jurassic or Cretaceous). Later on, the influence of Alpine (Tertiary) deformation have been very limited in the studied volume. For instance dolomite veins are sometimes overprinted by bed-inclined stylolites consistent with Alpine shortening axes, but no large Alpine fault is present in the studied outcrops. Cathodoluminescence microscopy allowed recognizing different growth stages saddle dolomite crystals, which point to varying precipitation conditions during three main stages of dolomitization. Dolomite and calcite crystal twinning suggests deformation under increasing temperature conditions, consistent with intracrystalline plasticity deformation mechanisms. The presence of cataclasites composed of hydrothermal dolostone clasts, in turn cemented by dolomite, or of dolomite veins and compaction

  17. Injectable contraception.

    PubMed

    Kaunitz, A M

    1989-06-01

    The most effective, convenient, reversible method of birth control is considered to be long-acting progestogen injections. Used by over 90 countries, Depot medroxy-progesterone acetate (DMPA, Depo-Provera, Upjohn) has yet to be approved by the U.S. Food and Drug Administration. The reluctance of the FDA to approve DMPA and much of the controversy surrounding this method revolve around the results of testing done on animals who were given large doses of the progestogen over a long period of time and developed tumors. However, the large body of research and records on this method that have been compiled over the past 30 years is positive. The injectable method works like oral contraceptives, inhibiting ovulation. Changes in menstruation have been the chief complaint of women who use this method; however, the duration and frequency of spotting and bleeding diminish over time. Other side effects of DMPA and Norethindrone enanthate (NET EN, Noristerat, Schering) are discussed. Also discussed is the history of development and testing for the 2 methods and subdermal implants, specifically Norplant.

  18. Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 3. Use of microspheres to estimate the transport potential of Cryptosporidium parvum oocysts

    USGS Publications Warehouse

    Harvey, R.W.; Metge, D.W.; Shapiro, A.M.; Renken, R.A.; Osborn, C.L.; Ryan, J.N.; Cunningham, K.J.; Landkamer, L.

    2008-01-01

    The vulnerability of a municipal well in the Northwest well field in southeastern Florida to potential contamination by Cryptosporidium parvum oocysts was assessed in a large-scale, forced-gradient (convergent) injection and recovery test. The field study involved a simultaneous pulse introduction of a nonreactive tracer (SF6, an inert gas) and oocyst-sized (1.6, 2.9, and 4.9 ??m diameter) carboxylated polystyrene microspheres into karst limestone of the Biscayne aquifer characterized by a complex triple (matrix, touching-vug, and conduit) porosity. Fractional recoveries 97 m down gradient were inversely related to diameter and ranged from 2.9% for the 4.9 ??m microspheres to 5.8% for 1.6 ??m microspheres. Their centers of mass arrived at the pumping well approximately threefold earlier than that of the nonreactive tracer SF6 (gas), underscoring the need for use of colloid tracers and field-scale tracer tests for these kinds of evaluations. In a modified triaxial cell using near in situ chemical conditions, 2.9 and 4.9 ??m microspheres underestimated by fourfold to sixfold the attachment potential of the less electronegative 2.9-4.1 ??m oocysts in the matrix porosity of limestone core samples. The field and laboratory results collectively suggested that it may take 200-300 m of transport to ensure even a 1-log unit removal of oocysts, even though the limestone surfaces exhibited a substantive capability for their sorptive removal. The study further demonstrated the utility of microspheres as oocyst surrogates in field-scale assessments of well vulnerability in limestone, provided that differences in attachment behaviors between oocysts and microspheres are taken into account. Copyright 2008 by the American Geophysical Union.

  19. Pathogen and chemical transport in the karst limestone of the Biscayne aquifer: 3. Use of microspheres to estimate the transport potential of Cryptosporidium parvum oocysts

    NASA Astrophysics Data System (ADS)

    Harvey, Ronald W.; Metge, David W.; Shapiro, Allen M.; Renken, Robert A.; Osborn, Christina L.; Ryan, Joseph N.; Cunningham, Kevin J.; Landkamer, Lee

    2008-08-01

    The vulnerability of a municipal well in the Northwest well field in southeastern Florida to potential contamination by Cryptosporidium parvum oocysts was assessed in a large-scale, forced-gradient (convergent) injection and recovery test. The field study involved a simultaneous pulse introduction of a nonreactive tracer (SF6, an inert gas) and oocyst-sized (1.6, 2.9, and 4.9 μm diameter) carboxylated polystyrene microspheres into karst limestone of the Biscayne aquifer characterized by a complex triple (matrix, touching-vug, and conduit) porosity. Fractional recoveries 97 m down gradient were inversely related to diameter and ranged from 2.9% for the 4.9 μm microspheres to 5.8% for 1.6 μm microspheres. Their centers of mass arrived at the pumping well approximately threefold earlier than that of the nonreactive tracer SF6 (gas), underscoring the need for use of colloid tracers and field-scale tracer tests for these kinds of evaluations. In a modified triaxial cell using near in situ chemical conditions, 2.9 and 4.9 μm microspheres underestimated by fourfold to sixfold the attachment potential of the less electronegative 2.9-4.1 μm oocysts in the matrix porosity of limestone core samples. The field and laboratory results collectively suggested that it may take 200-300 m of transport to ensure even a 1-log unit removal of oocysts, even though the limestone surfaces exhibited a substantive capability for their sorptive removal. The study further demonstrated the utility of microspheres as oocyst surrogates in field-scale assessments of well vulnerability in limestone, provided that differences in attachment behaviors between oocysts and microspheres are taken into account.

  20. Hydrologic monitoring of a waste-injection well near Milton, Florida, June 1975 - December 1976

    USGS Publications Warehouse

    Pascale, Charles A.; Martin, J.B.

    1977-01-01

    Hydraulic and chemical data were collected through a monitoring program conducted by the U.S. Geological Survey at an industrial liquid-waste injection site 6 mi southwest of Milton, Fla., in Santa Rosa County. The injection system is described. Data include injection rates, volumes, and pressures; water-level data at three monitor wells and a standby injection well, and field and laboratory analyses of water samples from four wells. Hydraulic and geochemical effects of the waste-injection system at the plant as of December 31, 1976, have been detected only in the injection zone, the lower limestone of the Floridan aquifer. Increased pressures are evident at the three wells used to monitor the injection zone. Geochemical changes have been noted only at the deep-test monitor well closest to the injection well. (Woodard-USGS)

  1. 77 FR 60458 - Public Land Order No. 7803; Withdrawal of Public Lands for the Limestone Hills Training Area; MT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... hours. SUPPLEMENTARY INFORMATION: The Limestone Hills Training Area withdrawal will maintain the current... Bureau of Land Management Public Land Order No. 7803; Withdrawal of Public Lands for the Limestone Hills... laws, for a period of 5 years. This withdrawal will protect the Limestone Hills Training Area...

  2. Landing and Oviposition Responses of Rhagoletis indifferens (Dipt., Tephritidae) on Sweet Cherry Treated with Kaolin- and Limestone-Based Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kaolin- and limestone-based products were compared for their effects on landing and oviposition on sweet cherry by Rhagoletis indifferens Curran (Dipt., Tephritidae). Surround (95% calcined kaolin), Cocoon (100% hydrous kaolin), Eclipse (>97% limestone), and Purshade (62.5% limestone) were studied....

  3. Effects of impurities on the removal of heavy metals by natural limestones in aqueous systems.

    PubMed

    Sdiri, Ali; Higashi, Teruo; Jamoussi, Fakher; Bouaziz, Samir

    2012-01-01

    Effects of impurities on the removal of heavy metals by natural limestones in aqueous solutions were studied by evaluating various factors including limestone concentration, pH, contact time and temperature. Solutions of Pb(II), Cd(II), Cu(II) and Zn(II), prepared from chloride reagents at a concentration of 10 mg/L, were studied in a batch method. Four natural limestone samples, collected from the Campanian-Maastrichtian limestone beds in Tunisia, were used as adsorbents. Sorption experiments indicated that high removal efficiencies could be achieved. Limestone samples containing impurities, such as silica, iron/aluminum oxides and different kinds of clay minerals, demonstrated enhanced sorption capacity, nearing 100% removal in some cases. Kinetic experiments showed that the sorption of metal ions occurred rapidly at a low coverage stage, and that solutions were nearly at equilibrium after 60 min. Data trends generally fit pseudo-second order kinetic, and intra-particle diffusion, models. The following conditions were found to promote optimum, or near-optimum, sorption of heavy metals: 1) contact time of more than 60 min, 2) pH = 5, 3) >3 g/L limestone concentration and 4) T = 35 °C. The results of this study suggest that the limestones from northern Tunisia, that contain higher amounts of silica and iron/aluminum oxides, are promising adsorbents for the effective removal of toxic heavy metals from wastewaters. PMID:22054591

  4. Stratigraphy and sedimentology of the Upper Cretaceous (Campanian) Anacacho Limestone, Texas, USA

    USGS Publications Warehouse

    Swezey, C.S.; Sullivan, E.C.

    2004-01-01

    The Upper Cretaceous Anacacho Limestone is exposed in outcrops between the cities of San Antonio and Del Rio, Texas. A detailed study of four outcrops (Blanco Creek section, Sabinal River section, Seco Creek section, Hondo Creek section) shows that the Anacacho Limestone rests on the Upson Clay (which contains fauna of early Campanian age) and is overlain by the Corsicana Marl (which contains fauna of early Maastrichtian age). An unconformity within the Anacacho Limestone is used herein to separate the limestone into a lower member and an upper member. The lower Anacacho member contains fauna of early Campanian age, whereas the upper Anacacho member contains fauna of middle Campanian age. The lower Anacacho member consists predominantly of wackestones to packstones, which are overlain by packstones to grainstones capped by the unconformity. This unconformity is interpreted as a marine flooding surface, delineating a transition from carbonate grainstones deposited in shallow water (<30 m depth) to a chalk deposited in deeper water. Above the unconformity, the upper Anacacho member is characterized by a chalk, overlain by wackestones and packstones. The uppermost section of the Anacacho Limestone consists of packstones and grainstones with abundant and diverse fossils. Most of the Anacacho Limestone developed in relatively shallow water (<50 m depth) leeward of a large carbonate build-up (possibly a rudistid reef) that now comprises the Anacacho Mountains. The environment, however, was open to marine water throughout deposition of the Anacacho Limestone. ?? 2004 Elsevier Ltd. All rights reserved.

  5. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    SciTech Connect

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  6. ARD remediation with limestone in a CO2 pressurized reactor

    USGS Publications Warehouse

    Sibrell, Philip L.; Watten, Barnaby J.; Friedrich, Andrew E.; Vinci, Brian J.

    2000-01-01

    We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous flow reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 °C; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron, 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 μS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p<0.001) and CO2 pressure (p<0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.

  7. Rehabilitation of lands mined for limestone in the Indian desert

    USGS Publications Warehouse

    Sharma, K.D.; Kumar, S.; Gough, L.P.

    2000-01-01

    In the Indian desert, the economics of mining is second only to agriculture in importance. However, research on the rehabilitation of land disturbed by mining has only recently received serious attention. An attempt has been made to determine both the qualitative and quantitative success of rehabilitation plans used to revegetate limestone mine spoils in an area near Barna, northwest arid India. Rehabilitation success was achieved using a combination of rainwater harvesting techniques, soil amendment application approaches, plant establishment methods and the selection of appropriate germplasm material (trees, shrubs and grasses). It is expected that the resulting vegetative cover will be capable of self-perpetuation under natural conditions while at the same time meeting the land-use needs of the local people. The minespoils have adequate levels of the major nutrients (except P, Mo and Se) for proper plant and grazing animal health. Levels of organic matter are low whereas total B concentrations are exceptionally high. Also, the population of soil fungi, Azotobactor, and nitrifying bacteria is negligible. Enhanced plant growth was achieved in treated plots, compared to control plots, where spoil moisture storage was improved by 5-45 per cent. Due to the decomposition of farmyard manure and nitrogen fixation by planted leguminous plant species, the electrical conductance of treated mine spoils increased threefold, CaCO3 content decreased from 20??0 to 5??2 per cent, and organic carbon, P, K, and biological activity increased significantly. The rehabilitation protocol used at the site appears to have been successful because plant self-regeneration is occurring. The increased diversity of woody perennials resulted in 'dominance' being better shared among species and 'evenness' being increased within the plant community elements. The early to mid-successional trends are continuing for six years following initial rehabilitation. This study developed methods for the

  8. Epidural Steroid Injections

    MedlinePlus

    ... Assessment Tools Injection Treatments for Spinal Pain Epidural Steroid Injections Lumbar Zygapophysial (Facet) Joint Injections Surgical Options Nonsurgical Treatments Alternative Medicine Epidural Steroid Injections General Information Why Get an Epidural Steroid ...

  9. Celestite in the Weathering Crust on Limestone Exposed to an Urban Atmosphere in Cracow (Poland)

    NASA Astrophysics Data System (ADS)

    Wilczyńska-Michalik, Wanda; Michalik, Marek

    2006-01-01

    Celestite containing very low amounts of barium occurs in weathering reaction zones developed on the Pińczów limestone exposed to the polluted atmosphere of Cracow. The mineral occurs both in limestone pore spaces filled with gypsum and in black gypsum crust. The Pińczów limestone contains ca 500 ppm strontium which was released during the reaction with atmospheric pollutants. The nucleation and growth of celestite, requiring significant concentration of components in evaporating solutions, is associated with gypsum crystallization.

  10. Desulfurization with a modified limestone formulation in an industrial CFBC boiler

    SciTech Connect

    Young Goo Park; Seung Ho Kim

    2006-02-01

    This work presents a practical result of experimental investigation of the limestone particle size effect on de-SOx from a circulating fluidized bed combustion (CFBC) boiler that burns domestic anthracite and is the first industrial scale in Korea. Because of combustion problems such as clinker formation, fine limestone has not been used as a desulfurization agent. The present test, however, showed that higher content (up to 50%) of the particles under 0.1 mm did not entail any malfunction in a modern CFBC system. In addition, the desulfurization efficiency was found to be comparable to the old mode of limestone sorbents. 17 refs., 4 figs., 3 tabs.

  11. Meteoric stabilization and preservation of limestone within late Proterozoic Beck Spring Dolomite of eastern California

    SciTech Connect

    Zempolich, W.G.; Wilkinson, B.H.; Lohmann, K.C.

    1989-04-01

    Petrographic and geochemical study of limestone, silicified carbonate, and dolostone indicates that meteoric diagenetic processes and paleogeographic position played important roles in the stabilization and preservation of limestone within the pervasively dolomitized Beck Spring Dolomite. The authors conclude that Beck Spring marine cement allochems precipitated as aragonite and high-magnesium calcite. In the vicinity of Saratoga Spring, these metastable mineralogies were dissolved, eroded, stabilized to calcite, and replaced by silica through interaction with meteoric waters. Early stabilization of limestone components along the margin of the Amargosa basin apparently decreased susceptibility to subsequent dolomitization.

  12. Streptomyces canchipurensis sp. nov., isolated from a limestone habitat.

    PubMed

    Li, Wen-Jun; Nimaichand, Salam; Jiang, Zhao; Liu, Min-Jiao; Khieu, Thi-Nhan; Kim, Chang-Jin; Hozzein, Wael N; Park, Dong-Jin; Wadaan, Mohammed A M; Ningthoujam, Debananda S

    2014-12-01

    Hundung Limestone habitat, Manipur, India is an unexplored site for microbial diversity studies. Using polyphasic taxonomy, a Streptomyces strain, MBRL 172(T), has been characterized. The strain was found to show highest 16S rRNA gene sequence similarity with Streptomyces coeruleofuscus NBRC 12757(T) (99.2 %). The DNA relatedness between MBRL 172(T) and S. coeruleofuscus NBRC 12757(T), and between MBRL 172(T) and Streptomyces nogalater NBRC 13445(T), were 36.8 ± 4.4 and 52.5 ± 2.7 %, respectively. Strain MBRL 172(T) was found to contain LL-diaminopimelic acid as the diagnostic diamino acid and glucose, mannose and xylose as the major sugars in whole cell hydrolysates. The polar lipids in the cell membrane were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositolmannoside. The predominant menaquinones detected were MK-9(H6) and MK-9(H8). The cellular fatty acids identified were mainly saturated fatty acids: anteiso-C15:0, iso-C16:0 and iso-C15:0. Based on differences in the biochemical and molecular characteristics from its closest relatives, the strain can be proposed to represent a novel taxon in the genus Streptomyces, for which the name Streptomyces canchipurensis is proposed, with the type strain MBRL 172(T) (=JCM 17575(T) = KCTC 29105(T)).

  13. Multispectral analysis of limestone, dolomite, and granite, Mill Creek, Oklahoma

    NASA Technical Reports Server (NTRS)

    Rowan, L. C.; Watson, K.

    1970-01-01

    Spectral reflectance and thermal emission data were collected at the Mill Creek, Oklahoma test site during NASA missions 132 and 133 in June 1970. The data were collected by three aircraft flown several times during the diurnal cycle at altitudes of 150 to 17,000 m above mean terrain. Reflectance of the main rock types (limestone, dolomite, and granite) was determined from the data collected using a 12-channel multispectral scanner during mission 133 and from thermal infrared images recorded during mission 132 on an RS-7 scanner from 17,000 m above terrain. A preliminary rock recognition map was generated automatically using data collected from 900 m above terrain. The discrimination provided by the map is reasonably accurate. Misidentification occurred in areas of unusually high dolomite reflectivity. High altitude thermal infrared (10 to 12 micrometers) images show regional folds and faults distinguished by the presence of thermally contrasting materials. Linear and curvilinear structural features two to three times smaller than the nominal 17 m resolution could be detected.

  14. A procedure to evaluate environmental rehabilitation in limestone quarries.

    PubMed

    Neri, Ana Claudia; Sánchez, Luis Enrique

    2010-11-01

    A procedure to evaluate mine rehabilitation practices during the operational phase was developed and validated. It is based on a comparison of actually observed or documented practices with internationally recommended best practices (BP). A set of 150 BP statements was derived from international guides in order to establish the benchmark. The statements are arranged in six rehabilitation programs under three categories: (1) planning (2) operational and (3) management, corresponding to the adoption of the plan-do-check-act management systems model to mine rehabilitation. The procedure consists of (i) performing technical inspections guided by a series of field forms containing BP statements; (ii) classifying evidences in five categories; and (iii) calculating conformity indexes and levels. For testing and calibration purposes, the procedure was applied to nine limestone quarries and conformity indexes were calculated for the rehabilitation programs in each quarry. Most quarries featured poor planning practices, operational practices reached high conformity levels in 50% of the cases and management practices scored moderate conformity. Despite all quarries being ISO 14001 certified, their management systems pay low attention to issues pertaining to land rehabilitation and biodiversity. The best results were achieved by a quarry whose expansion was recently submitted to the environmental impact assessment process, suggesting that public scrutiny may play a positive role in enhancing rehabilitation practices. Conformity indexes and levels can be used to chart the evolution of rehabilitation practices at regular intervals, to establish corporate goals and for communication with stakeholders. PMID:20630648

  15. Transport studies of radon in limestone underlying houses

    SciTech Connect

    Gammage, R.B.; Dudney, C.S.; Wilson, D.L.; Saultz, R.J.

    1990-01-01

    In hilly limestone terrains of the southern Appalachians, subterranean networks of solution cavities and fissures present circulatory systems facilitating convective and advective transport of radon-bearing gas. Evidence suggests that the primary driving forces for transport are aerostatic pressure differentials created by the difference between the underground and the outside air temperatures. Examples are presented of houses experiencing elevated indoor radon levels as a consequence of communicating with such subsurface transportation systems. The location of a house near the upper or lower end of a subterranean-circulatory system seems to produce amplification of indoor radon levels in winter or summer, respectively. The transport mechanism for radon-bearing air in karst and its impact on indoor radon need better understanding, both in regard to evaluating the geographical prevalence of the phenomenon and the induced spatial and temporal effects that are possible. This paper reports field studies made at houses in karst regions at Oak Ridge, Tennessee, and Huntsville, Alabama. A primary radon-transport mechanism is advocated of ascending or descending subsurface columns of air whose flows are largely driven by aerostatic pressure gradients created by the inground-outdoor air temperature differentials. 5 refs., 5 figs., 1 tab.

  16. Acid neutralization within limestone sand reactors receiving coal mine drainage

    USGS Publications Warehouse

    Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

    2005-01-01

    Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity = 31.22 + 2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30 s/30 s to 10 s/50 s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent. ?? 2005 Elsevier Ltd. All rights reserved.

  17. Recovering fresh water stored in saline limestone aquifers.

    USGS Publications Warehouse

    Merritt, M.L.

    1986-01-01

    Numerical modeling techniques are used to examine the hydrogeologic, design, and management factors governing the recovery efficiency of subsurface fresh-water storage. The modeling approach permitted many combinations of conditions to be studied. A sensitivity analysis was used that consisted of varying certain parameters while keeping constant as many other parameters or processes as possible. The results show that a loss of recovery efficiency resulted from: 1) processes causing mixing of injected fresh water with native saline water (hydrodynamic dispersion); 2) processes or conditions causing the irreversible displacement of the injected fresh water with respect to the well (buoyancy stratification and background hydraulic gradients); or 3) processes or procedures causing injection and withdrawal flow patterns to be dissimilar (dissimilar injection and withdrawal schedules in multiple-well systems). Other results indicated that recovery efficiency improved considerably during the first several successive cycles, provided that each recovery phase ended whgen the chloride concentration of withdrawn water exceeded established criteria for potability (usually 250 milligrams per liter). Other findings were that fresh water injected into highly permeable or highly saline aquifers would buoy rapidly with a deleterious effect on recovery efficiency. -Author

  18. The propagation and seismicity of dyke injection, new experimental evidence

    NASA Astrophysics Data System (ADS)

    Bakker, Richard R.; Fazio, Marco; Benson, Philip M.; Hess, Kai-Uwe; Dingwell, Donald B.

    2016-03-01

    To reach the surface, dykes must overcome the inherent tensile strength of the country rock. As they do, they generate swarms of seismic signals, frequently used for forecasting. In this study we pressurize and inject molten acrylic into an encapsulating host rocks of (1) Etna basalt and (2) Comiso limestone, at 30 MPa of confining pressure. Fracture was achieved at 12 MPa for Etna basalt and 7.2 MPa for Comiso limestone. The generation of radial fractures was accompanied by acoustic emissions (AE) at a dominant frequency of 600 kHz. During "magma" movement in the dykes, AE events of approximately 150 kHz dominant frequency were recorded. We interpret our data using AE location and dominant frequency analysis, concluding that the seismicity associated with magma transport in dykes peaks during initial dyke creation but remains significant as long as magma movement continues. These results have important implications for seismic monitoring of active volcanoes.

  19. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Youngdahl, C.A.

    1987-08-01

    Weight losses of marble and limestone samples exposed to outdoor environments at field sites in the eastern United States have been monitored in studies initiated in 1984. The prodcedures are described, and the results are tabulated and discussed. A rate of marble loss approximately equivalent to 16 ..mu..m of surface recession per year was found in North Carolina, and losses of this order were also observed in New Jersey, New York, and Washington, DC. Limestone weight losses were much higher than for marble in the first year; loss of extraneous materials from the porous limestone appeared to be a likely contributor to the overall loss. The rate of limestone loss diminished in the second year, though it continued to be higher than for marble. Exposures are continuing in a planned 10-yr program of tests. 8 refs., 3 figs., 5 tabs.

  20. Studies on the reaction of calcined limestone with sulfur dioxide: Topical report, October 1985-September 1986

    SciTech Connect

    Sotirchos, S.V.

    1986-10-01

    The primary objective of this project, which constitutes a balanced program of theoretical and experimental work, is the development of a systematic procedure for the description of the sorptive capacity for SO/sub 2/ removal of a given limestone or dolomite starting from basic physical principles and experimental information. Our research chiefly focusses on the experimental and theoretical investigation of the effects of the initial pore structure of limestone or dolomite and of its evolution with the progress of the reaction on the transient behavior of calcined limestone or dolomite particles reacting in an environment of SO/sub 2/ and O/sub 2/. Particular attention is paid to the effects of the intraparticle mass transport process on the sorpting capacity of reacting limestone particles.

  1. Hydration study of limestone blended cement in the presence of hazardous wastes containing Cr(VI)

    SciTech Connect

    Trezza, M.A.; Ferraiuelo, M.F

    2003-07-01

    Considering the increasing use of limestone cement manufacture, the present paper tends to characterize limestone behavior in the presence of Cr(VI). The research reported herein provides information regarding the effect of Cr(VI) from industrial wastes in the limestone cement hydration. The cementitious materials were ordinary Portland cement, as reference, and limestone blended cement. The hydration and physicomechanical properties of cementitious materials and the influence of chromium at an early age were studied with X-ray diffraction (XRD), infrared spectroscopy (FTIR), conductimetric and mechanical tests. Portland cement pastes with the addition of Cr(VI) were examined and leaching behavior with respect to water and acid solution were investigated. This study indicates that Cr(VI) modifies the rate and the components obtained during the cement hydration.

  2. Primary deforestation and regrowth on limestone slopes on Vancouver Island, British Columbia

    SciTech Connect

    Harding, K.A.; Ford, D.C. . Dept. of Geography)

    1992-01-01

    Limestones, well bedded and steeply dipping, are common in northern Vancouver Island. They have been glaciated and host a high density of postglacial karren (dissolution pits, grooves and troughs linked to underlying caves). There is rich, mature forest cover of western hemlock, silver fir and red cedar that is rooted in the karren or in overlying glacial deposits. Logging commenced around 1900 AD, intensifying after 1960 with clear cutting and (often) burning of slash. Impacts were investigated quantitatively by comparing sixteen limestone sites with eight on adjoining volcanic rocks. Some sites on each retained original forest, other were cleared. It was found that soil losses following logging are significantly greater on the limestones because of wash into karren (the epikarst zone). Regrowth is retarded on the limestones also; one site cleared in 1911 had regained approximately 17% of its original volume of timber 75 years later.

  3. Remediation of acid mine drainage at the friendship hill national historic site with a pulsed limestone bed process

    USGS Publications Warehouse

    Sibrell, P.L.; Watten, B.; Boone, T.; ,

    2003-01-01

    A new process utilizing pulsed fluidized limestone beds was tested for the remediation of acid mine drainage at the Friendship Hill National Historic Site, in southwestern Pennsylvania. A 230 liter-per-minute treatment system was constructed and operated over a fourteen-month period from June 2000 through September 2001. Over this period of time, 50,000 metric tons of limestone were used to treat 50 million liters of water. The influent water pH was 2.5 and acidity was 1000 mg/L as CaCO3. Despite the high potential for armoring at the site, effluent pH during normal plant operation ranged from 5.7 to 7.8 and averaged 6.8. As a result of the high influent acidity, sufficient CO2 was generated and recycled to provide a net alkaline discharge with about 50 mg/L as CaCO3 alkalinity. Additions of commercial CO2 increased effluent alkalinity to as high as 300 mg/L, and could be a useful process management tool for transient high flows or acidities. Metal removal rates were 95% for aluminum (60 mg/L in influent), 50 to 90% for iron (Fe), depending on the ratio of ferrous to ferric iron, which varied seasonally (200 mg/L in influent), and <10% of manganese (Mn) (10 mg/L in influent). Ferrous iron and Mn removal was incomplete because of the high pH required for precipitation of these species. Iron removal could be improved by increased aeration following neutralization, and Mn removal could be effected by a post treatment passive settling/oxidation pond. Metal hydroxide sludges were settled in settling tanks, and then hauled from the site for aesthetic purposes. Over 450 metric tons of sludge were removed from the water over the life of the project. The dried sludge was tested by the Toxicity Characteristics Leaching Protocol (TCLP) and was found to be non-hazardous. Treatment costs were $43,000 per year and $1.08 per m 3, but could be decreased to $22,000 and $0.51 per m3 by decreasing labor use and by onsite sludge handling. These results confirm the utility of the new

  4. Origin and Evolution of Limestone Caves of Chhattisgarh and Orissa, India: Role of Geomorphic, Tectonic and Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Gautam, P. K.; Allu, N. C.; Ramesh, R.; Yadava, M. G.; Panigrahi, C. P.

    2014-12-01

    Carbonate rocks undergo karstic process and karst morphology is a key to understand the nature and genesis of caves. The primary energy source for the formation of karst landforms is hydrological cycle. Geomorphic features along with hydrological characteristics provide important information not only on karst formation but also climate and environmental conditions. In this paper, we present the tectonic and geomorphic features that played a role in evolution of caves located in Chhattisgarh and Orissa States of India. The geomorphic and tectonic aspects of Kotumsar, Kailash, and Gupteshwar caves are discussed in relation to the origin and evolution of these caves. Caves are located near the water falls. The area is folded and faulted along the Eastern Ghat Mobile Belt (EGMB) due to tectonic reactivation. Shaly-limestone beds exhibit vertical dipping near Gupteshwar cave, and steeply inclined near Kotumsar and Kailash caves. Indrāvati and Sabari/Kolab tributaries of the Godavari River drain the area. The landscape evolution and the origin of caves in the region is a multistage process, where the lithology, orogeny, fluvial action, and monsoon are the main agents, which is similar to the four state model (Ford and Ewers, 1978). The river basin evolution and regional tectonism also caused the initiation of karstification in the region. The evolution of caves is believed to have taken place in Pre-Pliocene under more humid conditions that coincided with the initiation of monsoon in India. Further, during the Quaternary wet-dry/cold-warm phases altered physical and chemical weathering of limestone rocks. Contrasting relief features of Bastar plateau have also helped the extensive cave formation in the region. The dissolution along weak planes initiated the openings of caves, further enlarged by geomorphic agents. Both monsoon and tectonics have caused fluctuations in water levels along river courses, which acted as active agents in evolution of caves.

  5. The minimal response to contact metamorphism by the Devonian Buchan Caves Limestone, Buchan Rift, Victoria, Australia

    USGS Publications Warehouse

    Barker, C.E.; Bone, Y.

    1995-01-01

    A 2.2 m thick, Late Eocene (?) dike that intruded the Devonian Buchan Caves Limestone, near Murrindal, Victoria, has produced a narrow contact aureole only centimeters wide in the adjacent host rock. The lack of response of the Buchan Caves Limestone to contact metamorphism is attributed to: 1) prior heating to near 200??C; and 2) the fact that the dike intruded into cool, near surface, low-porosity rocks which may have been in the vadose zone. -from Authors

  6. Size and performance of anoxic limestone drains to neutralize acdic mine drainagei

    USGS Publications Warehouse

    Cravotta, C.A.

    2003-01-01

    Acidic mine drainage (AMD) can be neutralized effectively in underground, anoxic limestone drains (ALDs). Owing to reaction between the AMD and limestone (CaCO3), the pH and concentrations of alkalinity and calcium increase asymptotically with detention time in the ALD, while concentrations of sulfate, ferrous iron, and manganese typically are unaffected. This paper introduces a method to predict the alkalinity produced within an ALD and to estimate the mass of limestone required for its construction on the basis of data from short-term, closed-container (cubitainer) tests. The cubitainer tests, which used an initial mass of 4 kg crushed limestone completely inundated with 2.8 L AMD, were conducted for 11 to 16 d and provided estimates for the initial and maximum alkalinities and corresponding rates of alkalinity production and limestone dissolution. Long-term (5-11 yr) data for alkalinity and CaCO3 flux at the Howe Bridge, Morrison, and Buck Mountain ALDs in Pennsylvania, USA, indicate that rates of alkalinity production and limestone dissolution under field conditions were comparable with those in cubitainers filled with limestone and AMD from each site. The alkalinity of effluent and intermediate samples along the flow path through the ALDs and long-term trends in the residual mass of limestone and the effluent alkalinity were estimated as a function of the computed detention time within the ALD and second-order dissolution rate models for cubitainer tests. Thus, cubitainer tests can be a useful tool for designing ALDs and predicting their performance.

  7. Laboratory-scale interaction between CO2-rich brine and limestone and sandstone under supercritical CO2 conditions

    NASA Astrophysics Data System (ADS)

    Garcia-Rios, Maria; Cama, Jordi; Luquot, Linda; Soler, Josep

    2014-05-01

    A test site for a prospective CO2 geological storage is situated in Hontomín (Burgos, northern Spain) with a reservoir rock that is composed of limestone (calcite) and sandstone (66 wt.% calcite, 28 wt.% quartz and 6 wt.% microcline). During and after CO2 injection, the resulting CO2-rich acid brine will likely promote the dissolution of carbonate minerals (calcite) and aluminosilicates (microcline). Since the reservoir Hontomín brine contains sulfate, gypsum (or anhydrite at depth) may precipitate. These coupled dissolution and precipitation reactions may induce changes in porosity and pore structure of the repository rocks. Percolations experiments with mechanically fractured cores (8.6 mm in diameter and 18 mm length) were performed under CO2 supercritical conditions (Pfluid = 150 bar; pCO2 ≡ 90 bar and T = 60 ºC) in order to evaluate and quantify variations in fracture permeability, preferential path formation and fracture volume. The brine sulfate content and the flow rate were varied. Regarding limestone, as the synthetic brines circulated through the fracture, the fracture permeability initially increased slowly, to thereafter increase rapidly. This change was due to a localized dissolution process (wormhole formation) along the core that occurred regardless gypsum precipitation. Nonetheless, the originated fracture volume in the sulfate-rich brine experiments was a factor of two smaller than that in sulfate-free brine experiments. Also, an increase in flow rate from 0.2 to 60 mL/h increased the volume of both dissolved calcite and precipitated gypsum. Regarding sandstone, permeability increased gradually with time. Nonetheless, this increase was not always continuous due to eventual fracture clogging. Formation of wormholes was observed. Acknowledgements This study was financed by CIUDEN (Ciudad de la Energía), the Compostilla OXYCFB300 project and the PANACEA project (European Community's Seventh Framework Programme FP7/2007-2013 under grant

  8. An Unusual Process of Accelerated Weathering of a Marly Limestone

    NASA Astrophysics Data System (ADS)

    Ercoli, L.; Rizzo, G.; Algozzini, G.

    2003-04-01

    This work deals with a singular case of stone deterioration, which occurred during the restoration of the Cathedral of Cefalù. In particular, a significant process of stone decohesion started after a consolidation treatment on ashlars of the external face of the cloister portico. A study was carried out to characterize the stone and to investigate the deterioration process. Petrographical, chemical and physical analyses were performed on samples taken from the wall. The results indicate that the medieval monument was built using a Pliocene marly limestone, called "trubo", quarried from outcrops of the environs of Cefalù. The rock is soft and uniformely cemented. The carbonatic fraction of the rock is due to foraminifera shells; the rock also contains detritic quartz, feldspate and glauconite. The clay minerals, mainly illite and montmorillonite, are widespread in the rock in the form of thin layers. The use of such a stone in a building of relevant artistic value is definitely unusual. In fact, the "trubo" is a rock subjected to natural decay because of its mineralogical composition and fabric; as effect of natural weathering, in the outcrops the rock disaggregates uniformely, producing silt. In the cloister this effect was magnified by extreme environmental conditions (marine spray, severe excursions of both relative humidity and temperature). Furthermore, after soluble salts removing and subsequent consolidation with ethyl silicate, a significant acceleration of the decay process was observed, producing friable scales detach for a depth of about 3 cm into the ashlars. The stone appeared corroded and uneven. Experimental tests were performed in laboratory in order to evidence any origin of incompatibility between such stone composition and the treatments carried out, which on the other hand are the most generally adopted in restoration interventions.

  9. Techniques to improve the economics of limestone FGDS

    SciTech Connect

    Bresowar, G.E.; Klingspor, J.

    1995-12-31

    Many utilities have evaluated the cost of scrubbing versus fuel switching in various plans and scenarios to determine the most economical means for meeting the requirements of the new law. Presently, the future cost of removing a ton of SO{sub 2} is based on fuel switching, and the market values are in the range of $150 - $250 per ton. The perceived cost of FGDS retrofits is $250 - $400 per ton for eastern medium to high sulfur coal. ABB has studied the overall costs of FGDS and has developed a series of cost reducing improvements. and innovations. The improvements are manifested in ABBs new limestone FGDS technology known by the code phrase {open_quote}Stealth FGDS{close_quotes}. Stealth promises low capital and operating cost, high removal efficiencies for SO{sub 2} and other pollutants, little or positive environmental and economic impact on the local community, salable or non-hazardous by-products, ease of retrofit, and exceptionally short installation schedules. The concepts are being demonstrated in one system at the Miles Generating Station of Ohio Edison Company. Bearing the name {open_quote}LS-2 Advanced SO, Scrubbing{close_quotes}, the Stealth scrubber at Niles is a 110 MWe turnkey, retrofit unit to be completed 20 months after the release of engineering. It will remove 20,000 or more tons per year of SO{sub 2} from the flue gases generated by both Unit 1 and Unit 2 boilers, producing wallboard-grade gypsum. Upon completion of a four month test program, the plant will be operated by Ohio Edison for a four to five year reliability demonstration period. The performance and economic projections for LS-2 scrubbers show the technology to be quite attractive relative to projections for fuel switching when installed in a manner similar to the installation plan for Niles. The description and basis for these economic projections are described in this paper.

  10. Mangrove plantation over a limestone reef - Good for the ecology?

    NASA Astrophysics Data System (ADS)

    Asaeda, Takashi; Barnuevo, Abner; Sanjaya, Kelum; Fortes, Miguel D.; Kanesaka, Yoshikazu; Wolanski, Eric

    2016-05-01

    There have been efforts to restore degraded tropical and subtropical mangrove forests. While there have been many failures, there have been some successes but these were seldom evaluated to test to what level the created mangrove wetlands reproduce the characteristics of the natural ecosystem and thus what ecosystem services they can deliver. We provide such a detailed assessment for the case of Olango and Banacon Islands in the Philippines where the forest was created over a limestone reef where mangroves did not exist in one island but they covered most of the other island before deforestation in the 1940s and 1950s. The created forest appears to have reached a steady state after 60 years. As is typical of mangrove rehabilitation efforts worldwide, planting was limited to a single Rhizophora species. While a forest has been created, it does not mimic a natural forest. There is a large difference between the natural and planted forests in terms of forest structure and species diversity, and tree density. The high density of planted trees excludes importing other species from nearby natural forests; therefore the planted forest remains mono-specific even after several decades and shows no sign of mimicking the characteristics of a natural forest. The planted forests provided mangrove propagules that invaded nearby natural forests. The planted forest has also changed the substratum from sandy to muddy. The outline of the crown of the planted forest has become smooth and horizontal, contrary to that of a natural forest, and this changes the local landscape. Thus we recommend that future mangrove restoration schemes should modify their methodology in order to plant several species, maintain sufficient space between trees for growth, include the naturally dominant species, and create tidal creeks, in order to reproduce in the rehabilitated areas some of the key ecosystem characteristics of natural mangrove forests.

  11. Reducing energy-related CO2 emissions using accelerated weathering of limestone

    USGS Publications Warehouse

    Rau, G.H.; Knauss, K.G.; Langer, W.H.; Caldeira, K.

    2007-01-01

    The use and impacts of accelerated weathering of limestone (AWL; reaction: CO2+H2O+CaCO3???Ca2++2(HCO3-) is explored as a CO2 capture and sequestration method. It is shown that significant limestone resources are relatively close to a majority of CO2-emitting power plants along the coastal US, a favored siting location for AWL. Waste fines, representing more than 20% of current US crushed limestone production (>109 tonnes/yr), could provide an inexpensive or free source of AWL carbonate. With limestone transportation then as the dominant cost variable, CO2 mitigation costs of $3-$4/tonne appear to be possible in certain locations. Perhaps 10-20% of US point-source CO2 emissions could be mitigated in this fashion. It is experimentally shown that CO2 sequestration rates of 10-6 to 10-5 moles/sec per m2 of limestone surface area are achievable, with reaction densities on the order of 10-2 tonnes CO2 m-3day-1, highly dependent on limestone particle size, solution turbulence and flow, and CO2 concentration. Modeling shows that AWL would allow carbon storage in the ocean with significantly reduced impacts to seawater pH relative to direct CO2 disposal into the atmosphere or sea. The addition of AWL-derived alkalinity to the ocean may itself be beneficial for marine biota. ?? 2006 Elsevier Ltd. All rights reserved.

  12. Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

    2009-01-01

    Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

  13. A model for prediction of limestone dissolution in wet flue gas desulfurization applications

    SciTech Connect

    Brogren, C.; Karlsson, H.T.

    1997-09-01

    A model has been developed to predict the dissolution rate of a limestone slurry as a function of particle size distribution and limestone conversion. The model is based on basic mass-transfer theory and includes a factor allowing the flux of calcium ions from the limestone surface to vary with the fraction dissolved. Changes in the flux with the fraction dissolved have been reported to be caused by the presence of sulfite but can also be caused by accumulation of inerts at the liquid-solid interface and/or by changes in the effective mass-transfer area. Calculations show that the decrease in flux reported for sulfites can have a significant impact on the slurry conditions within the reaction tank, i.e., impact on the limestone conversion and the relationship between liquid and solid alkalinity. In the absence of sulfites, the flux from limestone particles has been assumed to be constant with respect to the degree of dissolution. The modeling results have been found to be in good agreement with the measured values of a continuous stirred tank reactor. The model was able to accurately predict the impact of both the particle size distribution and reaction tank residence time on limestone conversion and dissolution rate.

  14. Model for the sulfidation of calcined limestone and its use in reactor models

    SciTech Connect

    Heesink, A.B.M.; Brilman, D.W.F.; Swaaij, W.P.M. van

    1998-07-01

    Limestone, both in raw and in calcined form, can be used to remove H{sub 2}S from coal gas. A mathematical model describing the sulfidation of a single calcined limestone particle was developed and experimentally verified. This model, which includes no fitting parameters, assumes a calcined limestone particle to consist of spherical grains of various sizes that react with H{sub 2}S according to the elastic shrinking-core model. The initial size distribution of the grains is derived from mercury porosimetry. The transport of H{sub 2}S through the bidisperse limestone particle is calculated based on the random-pore model of Wakao and Smith, which distinguishes macropore and micropore zones. Knudsen diffusivity inside the micropore zones is calculated according to the dusty-gas approach. The single-particle model delivers the value of a new defined utilization factor, which includes effects of external mass-transfer limitation, pore-diffusion limitation, and grain-size distribution on particle reactivity. A correlation derived for a single batch of calcined limestone explicitly expresses this utilization factor as a function of conversion and relevant process parameters. This correlation can be easily incorporated into reactor models, as shown for an existing model describing the capture of H{sub 2}S by a fluidized bed of calcined limestone particles.

  15. Sedimentology and diagenesis of Miocene Lirio Limestone, Isla de Mona, Puerto Rico

    SciTech Connect

    Ruiz, H.; Gonzalez, L.A.; Budd, A.F. )

    1991-03-01

    Isla de Mona is a carbonate plateau, 50 mi west of Puerto Rico. The island lies on the southern portion of the Mona Platform. It is composed mostly of two Miocene carbonate units: Isla de Mona Dolomite overlain by Lirio Limestone. The Lirio Limestone was deposited on a sloping erosional surface over the Isla de Mona Dolomite. The Miocene Lirio Limestone consists mostly of backreef sands (packstones) with a reefal sequence (boundstones and grainstones) present in the southwestern portion of the island. The reefal sequence is made up mostly of Stylophora, Porites, and Millepora. Thin, discreet pockets of carbonate mud, rich in planktonic foraminifera and radiolarians and mixed with shallow benthic fauna/flora (foraminifera, echinoderms, red algae, and corals) interpreted as storm deposits, are found throughout the unit. An extensive reefal zone can be inferred to be present throughout the southwestern to southern portions of the Mona Platform. The Lirio Limestone is heavily karstified and is riddled with sinkholes on the plateau surfaces and caves around the periphery of the island. Caves are exposed around the periphery of the island, radiating from a depression in the central portions of the Lirio Limestone, near contacts with the Isla de Mona Dolomite, are partially dolomitized. The southwestern outcrops exhibit partial dolomitization throughout. The distribution of sinkholes, seaward caverns, and partial dolomitization of the lowermost Lirio Limestone suggests diagenetic modifications by meteoric fluids in central exposed portions of the island and by marine-meteoric fluids in the lowermost portions of the phreatic lens.

  16. Interpretation of well hydrographs in the karstic Maynardville Limestone at the Oak Ridge Y-12 Plant

    SciTech Connect

    Shevenell, L.A.; McMaster, B.W.

    1996-06-01

    The Maynardville Limestone in Oak Ridge, Tennessee underlies the southern portion of Bear Creek Valley (BCV), and is considered to be the primary pathway for groundwater leaving the Y-12 Plant boundaries. Sixty-seven percent of all wells drilled into the Maynardville Limestone have intersected at least one cavity, suggesting karst features may be encountered throughout the shallow (< 200 ft) portions of the Limestone. Because waste facilities at the Y-12 Plant are located adjacent to the Maynardville Limestone, contaminants could enter the karst aquifer and be transported in the conduit system. As part of an overall hydrologic characterization effort of this karst aquifer, 41 wells in the Maynardville Limestone were instrumented with pressure transducers to monitor water level changes (hydrographs) associated with rain events. Wells at depths between approximately 20 and 750 ft were monitored over the course of at least two storms in order that variations with depth could be identified. The wells selected were not exclusively completed in cavities but were selected to include the broad range of hydrologic conditions present in the Maynardville Limestone. Cavities, fractures and diffuse flow zones were measured at a variety of depths. The water level data from the storms are used to identify areas of quickflow versus slower flowing water zones. The data are also used to estimate specific yields and continuum transmissitives in different portions of the aquifer.

  17. Direct sulfation of limestone based on oxy-fuel combustion technology

    SciTech Connect

    Chen, C.M.; Zhao, C.S.; Liu, S.T.; Wang, C.B.

    2009-10-15

    With limestone as the sorbent, the sulfation reaction can proceed via two different routes depending on whether calcination of the limestone takes place under the given reaction conditions. The direct sulfation reaction is defined as the sulfation reaction between sulfur dioxide (SO{sub 2}) and limestone in an uncalcined state. This reaction, based on oxyfuel combustion technology, was studied by thermogravimetric analysis. Surface morphologies of the limestone particles after sulfation were examined by a scanning electron microscope. Results show that there are more pores or gaps in the product layer formed by direct sulfation of limestone than by indirect sulfation, which can be attributed to the generation of carbon dioxide (CO{sub 2}) at a reaction interface. Compared with indirect sulfation, direct sulfation of limestone can yield much higher conversion and has a much higher reaction rate. For direct sulfation, the greater porosity in the product layer greatly reduces the solid-state ion diffusion distance, resulting in a higher reaction rate and higher conversion.

  18. Hot dry rock reservoir engineering

    SciTech Connect

    Murphy, H.

    1987-01-01

    The Hot Dry Rock (HDR) concept is a simple one. Two nearly parallel wells are drilled, and hydraulic fractures are then formed to hydraulically connect the wells. Water pumped down the injection well and through the fracture system is heated by contact with the hot rock and rises to the production well. This hot fluid is passed through a heat exchanger at the surface and the extracted heat is used for direct heating or electricity generation. The cooled production fluid is then reinjected, thereby setting up a circulation loop. This paper describes the development and execution of the HDR project at Fenton Hill, New Mexico.

  19. BIOMASS DRYING TECHNOLOGIES

    EPA Science Inventory

    The report examines the technologies used for drying of biomass and the energy requirements of biomass dryers. Biomass drying processes, drying methods, and the conventional types of dryers are surveyed generally. Drying methods and dryer studies using superheated steam as the d...

  20. Nomination of the Globigerina Limestone of the Maltese Islands as a "Global Heritage Stone Resource"

    NASA Astrophysics Data System (ADS)

    Cassar, JoAnn

    2016-04-01

    The Maltese Islands consist of two main islands, Malta and Gozo, as well as a small number of islets, and lie in the central Mediterranean Sea approximately 90 km south of Sicily. Although only 316 square kilometres in size, the Islands contain a rich concentration of archaeological sites and historic buildings, as well as vernacular architecture and modern buildings, for the most part built of the local Globigerina Limestone, which is one of the few natural resources of the Islands. This stone can be described as a typical "soft limestone", very easy to carve and shape. It forms part of the large family of Oligo-Miocene "soft limestones" widely diffused in the Mediterranean Basin. The Maltese Globigerina Limestone Formation is one of five main Formations, and varies in thickness from 20 to over 200 m. The material used for building is located stratigraphically in the lower part of the Globigerina Limestone Formation, called the Lower Globigerina Limestone. This Formation is stratified into thick beds at outcrop. Sections where bioturbation is concentrated often also occur. This limestone is fine-grained, yellow to pale grey in colour, almost wholly composed of the tests of globigerinid planktonic foraminifera. Petrographically, Globigerina Limestone can be described as a bioclastic packstone, with bioclastic wackestones also occurring. This limestone has always been used as the predominant building material in the Islands. The Maltese prehistoric Temples, which were constructed approximately 6000 years ago, bear testimony to this. Between 1530 and 1798 the Order of the Knights of St John built kilometres of fortifications in this same material to protect the Island from the expanding Ottoman Empire. Fortifications, impressive churches, auberges and palaces were built of this stone during this period. The capital city of Valletta, a rich and dense manifestation of Baroque architecture in Globigerina Limestone, is included on the UNESCO World Heritage List, as are

  1. Comparative study of porous limestones used in heritage structures in Cyprus and in Hungary

    NASA Astrophysics Data System (ADS)

    Theodoridou, Magdalini; Ioannou, Ioannis; Rozgonyi-Boissinot, Nikoletta; Török, Ákos

    2015-04-01

    Porous limestone is widely used as construction material in the monuments of Cyprus and Hungary. The present study compares the physical properties of a bioclastic limestone from Cyprus and an oolitic limestone from Hungary. Petra Gerolakkou is a Pliocene limestone from Cyprus that originates from the district of Nicosia, the island's capital. It has been extensively used throughout the years in construction and restoration projects, particularly in the Nicosia area. Distinctive examples of its use can be found in the majority of the most important historic monuments in Nicosia, such as the Venetian walls and fortifications, churches (e.g. the Agia Sofia Cathedral), the archbishop and presidential palaces and a high number of other traditional buildings. The studied Miocene limestone from Hungary was exploited from Sóskút quarry (15-20 km W-SW to Budapest). The quarry provided stone for emblematic monuments of the capital of Hungary such as the Parliament building, Mathias Church, the Opera House and Citadella. In this study, mechanical parameters for both aforementioned stones, such as uniaxial compressive and tensile strengths, were tested under laboratory conditions. Their density, porosity and water absorption were also compared. The studied limestone from Cyprus exhibits porosity values within the range of 48-51%, apparent density between 1340 and 1400 kg/m3 and strength values under uniaxial compressive load between 1.2 and 2.8 MPa. This lithotype is also considered susceptible to salt decay, since an approximate mass loss of 12.5% is noted after 15 salt crystallization artificial weathering cycles. The porosity of the Hungarian limestone is in the order of 16-35%, the bulk density is 1600-1950 kg/m3, while the compressive strength is 2.5-15 MPa. Durability tests indicate that even after 10 freeze-thaw cycles the loss in strength is dramatic. Test results indicate that use of porous limestone in both countries is common and fabric strongly controls the

  2. Hip joint injection

    MedlinePlus

    ... injected so the provider can see where to place the medicine. The steroid medicine is slowly injected into the joint. After the injection, you will remain on the table for another 5 to 10 minutes or so. ...

  3. Cohesive model applied to fracture propagation in Indiana Limestone

    NASA Astrophysics Data System (ADS)

    Dewers, T. A.; Rinehart, A. J.; Bishop, J. E.

    2014-12-01

    We apply a cohesive fracture (CF) model to results of short-rod (SR), notched 3-point-bend (N3PB) tests, and Brazil tests in Indiana Limestone. Calibration and validation of the model are performed within a commercial finite element modeling platform. By using a linear traction-displacement softening response for a defined fracture-opening displacement (w1) following peak tensile stress (σcrit), the CF model numerically lumps different spatially distributed inelastic processes occurring at and around fracture tips into a thin zone within an elastic domain. Both the SR and the N3PB test specimen geometries use a notch partway through the sample to control the location of fracture propagation. We develop a mesh for both the SR and N3PB geometries with a narrow cohesive zone in the center of notches. From the Brazil tests, we find a tensile splitting stress (σsplit) of 5.9 MPa. We use a σsplit as the peak tensile stress (σcrit) for all simulations. The Young's modulus (E) and the critical crack opening distance (w1) of the CF model are calibrated against the SR data. The model successfully captures the elastic, yield, peak, and initial and late failure behavior and compares favorably against the N3PB tests. Differences in force-displacement and crack propagation are primarily caused by: more mixed-mode (shear and opening) crack propagation in N3PB than in SR tests, causing a higher peak; and transition from compression (high E) to tension (low E) in a larger volume of the N3PB sample than in the SR geometry. This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy

  4. Uncertainty Analysis of Geochemical Parameters Related To CO2 Leakage into an Unconfined Limestone Aquifer

    NASA Astrophysics Data System (ADS)

    Bacon, D. H.; Keating, E. H.; Viswanathan, H. S.; Dai, Z.

    2011-12-01

    Accurate prediction of the impact of leaking CO2 on groundwater quality is limited by the complexity of subsurface aquifers and the geochemical reactions that control drinking water compositions. As a result there is a high uncertainty associated with any predictions, hampering monitoring plans, interpretation of the monitoring results, and mitigation plans for a given site. Many physical and geochemical characteristics will dictate a drinking water aquifer's response to a CO2 leak. As a part of the National Risk Assessment Program (NRAP), funded by the U.S. Department of Energy, scientists at Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory (LANL) have collaborated on the development of a 3D heterogeneous model of the Edwards Aquifer in Texas to examine the impacts of CO2 leakage into an unconfined, carbonate aquifer. Using the same base case model, LANL has focused on uncertainty quantification (UQ) of the aquifer's hydraulic properties, whereas PNNL has examined the impact of uncertainty related to geochemical parameters. This abstract describes PNNL's work on geochemical UQ. The uncertainty analysis looks at the impact on several model outputs, including CO2 leakage rate from the water table, mean pH value, and pH<6.5 volume fraction. The uncertainty parameters are the leakage rate into the aquifer, the composition of the aquifer limestone, and the dissolution/precipitation rate for the limestone, which ranges over two orders of magnitude from laboratory-measured values for calcite to those for disordered dolomite. We also examine the impact on drinking water quality, specifically TDS, from leakage of brine from the underlying formation, forced upwards by increased pressure due to CO2 injection. To conduct these simulations we use STOMP-CO2-R, which is a multiphase flow simulator, coupled with the reactive transport module ECKEChem, developed at PNNL to simulate CO2 sequestration in deep saline formations and the associated

  5. Field and laboratory experiments on high dissolution rates of limestone in stream flow

    NASA Astrophysics Data System (ADS)

    Hattanji, Tsuyoshi; Ueda, Mariko; Song, Wonsuh; Ishii, Nobuyuki; Hayakawa, Yuichi S.; Takaya, Yasuhiko; Matsukura, Yukinori

    2014-01-01

    Field and laboratory experiments were performed to examine dissolution rates of limestone in stream flow. Field experiments were conducted in three stream sites (A-C) with different lithological or hydrological settings around a limestone plateau in the Abukuma Mts., Japan. Sites A and B are allogenic streams, which flow from non-limestone sources into dolines, and site C has a karst spring source. Tablets made of limestone from the same plateau with a diameter of 3.5 cm and a thickness of 1 cm were placed in the streams for 3 years (2008-2011) where alkalinity, pH and major cation concentrations were measured periodically. The saturation indices of calcite (SIc) of stream water were - 2.8 ± 0.4 at site A, - 2.5 ± 0.4 at site B and - 0.5 ± 0.4 at site C. Annual weight loss ratios for tablets were extremely high at site A (0.11-0.14 mg cm- 2 d- 1), high at site B (0.05 mg cm- 2 d- 1), and low at site C (0.005 mg cm- 2 d- 1). The contrasting rates of weight loss are mainly explained by chemical conditions of stream water. In addition, laboratory experiments for dissolution of limestone tablets using a flow-through apparatus revealed that flow conditions around the limestone tablet is another important factor for dissolution in the stream environment. These results revealed that limestone dissolves at a rapid rate where water unsaturated to calcite continuously flows, such as in an allogenic stream.

  6. Mineralogical characterization of the Shelburne Marble and the Salem limestone: Test stones used to study the effects of acid rain

    SciTech Connect

    McGee, E.S.

    1989-01-01

    The Salem Limestone and the Shelburne Marble are representative of limestones and marbles commonly used in buildings and monuments. Both stones are composed predominantly of calcite. The Salem Limestone is homogeneous in composition and mineralogic characteristics throughout the test block. The Shelburne Marble has compositionally homogeneous mineral phases, but the distribution of those phases within the test block is random. The mineralogy and physical characteristics of the Shelburne Marble and Salem Limestone test blocks described in the study provide a baseline for future studies of the weathering behavior of these stones. Because the Shelburne Marble and the Salem Limestone are representative of typical commercial marbles and limestones, they are likely to be useful in a consortium study of the effects of acid precipitation on these two types of building stones.

  7. Dynamic responses of photosystem II in the Namib Desert shrub, Zygophyllum prismatocarpum, during and after foliar deposition of limestone dust.

    PubMed

    van Heerden, P D R; Krüger, G H J; Kilbourn Louw, M

    2007-03-01

    The effects of limestone dust deposition on vegetation in desert ecosystems have not yet been reported. We investigated these effects in a succulent shrub from the Namib Desert at a limestone quarry near Skorpion Zinc mine (Namibia). Effects of limestone dust were determined in Zygophyllum prismatocarpum (dollar bush) plants with heavy, moderate and no visible foliar dust cover by means of chlorophyll a fluorescence measurements. Limestone dust deposition decreased overall plant performance through loss of chlorophyll content, inhibition of CO(2) assimilation, uncoupling of the oxygen-evolving complex and decreased electron transport. Importantly, dynamic recovery occurred after termination of limestone extraction at the quarry. Recovery was accelerated by rainfall, mainly because of dust removal from leaves and stimulation of new growth. These results indicate that limestone dust has severe effects on photosynthesis in desert shrubs, but that recovery is possible and that, in arid environments, this process is modulated by rainfall.

  8. Improved Water Flooding through Injection Brine Modification

    SciTech Connect

    Robertson, Eric Partridge; Thomas, Charles Phillip; Morrow, Norman

    2003-01-01

    Crude oil/brine/rock interactions can lead to large variations in the displacement efficiency of waterflooding, by far the most widely applied method of improved oil recovery. Laboratory waterflood tests show that injection of dilute brine can increase oil recovery. Numerous fields in the Powder River basin have been waterflooded using low salinity brine (about 500 ppm) from the Madison limestone or Fox Hills sandstone. Although many uncertainties arise in the interpretation and comparison of field production data, injection of low salinity brine appears to give higher recovery compared to brine of moderate salinity (about 7,000 ppm). Laboratory studies of the effect of brine composition on oil recovery cover a wide range of rock types and crude oils. Oil recovery increases using low salinity brine as the injection water ranged from a low of no notable increase to as much as 37.0% depending on the system being studied. Recovery increases using low salinity brine after establishing residual oil saturation (tertiary mode) ranged from no significant increase to 6.0%. Tests with two sets of reservoir cores and crude oil indicated slight improvement in recovery for low salinity brine. Crude oil type and rock type (particularly the presence and distribution of kaolinite) both play a dominant role in the effect that brine composition has on waterflood oil recovery.

  9. Drenov Grič black limestone as a heritage stone from Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Rožič, Boštjan; Žbona, Nina; Bedjanič, Mojca; Mladenović, Ana

    2016-04-01

    The limestone known as Drenov Grič black limestone is considered one of the most beautiful Slovenian natural stones due to its homogenous black colour interwoven with white veins. Over the centuries it has been exploited from three major quarries west of Ljubljana, with the main quarry at Drenov Grič playing the primary role in supplying building material for the central parts of Slovenia. All the quarries are currently not active. In the area of Drenov grič, one locality of black limestone is protected - Kuclerjev kamnolom quarry. It has the status of 'valuable natural feature of national importance' and is protected as a natural monument. This well-stratified micritic limestone of Triassic (Carnian) age occurs in 10-80 cm thick beds, with thin marl interlayers. The stone contains abundant fossil bivalves and ostracods. Apart from calcite as the main component, dolomite, quartz, illite/muscovite and pyrite are also present. The limestone is relatively rich in carbonaceous and bituminous organic matter, which is responsible for the black colour of the stone. This component does not have any adverse effect on mechanical and physical characteristics. As the lime¬stone is dense, thus facilitating a good polish, it has been commercially considered as marble. The stone has been widely used in Slovenian monuments, not only in Ljubljana but also in other regions of Slovenia. Many inner and outdoor architectural elements were made of this limestone, particularly in the baroque period, which was known for the extensive use of black limestones also in other European countries. The most significant use of this limestone has been recorded in sculptured portals and altars. Some of the important buildings decorated utilising this stone, are the Ljubljana Cathedral, the St. James's Parish Church, and the Franciscan Church of the Annunciation, all of which are located in Ljubljana, some of them having been declared as cultural monuments of local or national importance. When

  10. Limestones as a paleobathymeter for reconstructing past seismic activities: Muroto-misaki, Shikoku, southwestern Japan

    NASA Astrophysics Data System (ADS)

    Iryu, Y.; Maemoku, H.; Yamada, T.; Maeda, Y.

    2009-03-01

    Muroto-misaki (Cape Muroto) is located at the southern tip of the eastern half of Shikoku, southwestern Japan and is ~ 100 km north of the Nankai Trough where the Philippine Sea Plate is being subducted beneath the Eurasian Plate. Therefore, the Muroto-misaki area has been seismically uplifted. Sedimentologic analyses were conducted on Holocene limestones that occur along the coast from Muroto-misaki to Meoto-iwa, located ~ 13 km north of the cape. The limestones are limited to less than 9.2 m in elevation. The limestones are up to 4.4 m in mean diameter, up to 0.5 m in thickness, and consist mainly of fossilized sessile organisms, including annelids, corals, bryozoans, encrusting foraminifers, barnacles, nongeniculate coralline algae, and, to a lesser extent, molluscs and peyssonneliacean algae. Acicular and equant cements are minor components. Acicular cements are found in semi-closed spaces between coralline algal crusts and their substrates. The modal composition of limestones was determined by a point-counting technique. Based on the biotic composition, the Holocene limestones can be classified into six types (Types I to VI). A comparison of the vertical distribution of these rock types with that of modern sessile organisms indicates that the top of Type I limestone, which is characterized by the occurrence of hermatypic corals, corresponds approximately to the mean low water springs when the limestones formed. A difference in the highest occurrence of Type I limestone between two sites may represent the variation in the total amount of uplift over the last 1000 to 1500 years, which resulted in an apparent northward decline of paleo-mean low water springs at a rate of ~ 10 cm/km. Therefore, the Holocene limestones are a good paleobathymeter to reconstruct past seismic activities in this area. This study shows that warm temperate carbonate deposits are as excellent recorders of geologic events, such as the timing and scale of repeated coseismic uplifts and

  11. Acid mine drainage treatment with a combined wetland/anoxic limestone drain: Greenhouse and field systems

    SciTech Connect

    Skousen, J.; Sexstone, A.; Cliff, J.; Sterner, P.; Calabrese, J.; Ziemkiewicz, P.

    1999-07-01

    The most common methods for treating acid mine drainage (AMD) involve applying a strong base to neutralize the acidity and to precipitate metals. Limestone use in AMD treatment has been largely confined to anaerobic wetlands, anoxic limestone drains (ALDs) and open limestone channels. If Fe{sup 3+} and Al could be removed from AMD before introduction into limestone systems, then the use of limestone for AMD treatment could be greatly expanded. The authors developed and monitored a passive AMD system to determine if AMD containing Fe{sup 3+} as ferrous sulfides (FeS{sub x}) through sulfate reduction. Further, Fe and al may be adsorbed to organic matter in the wetland thereby eliminating the formation of metal hydroxides with subsequent plugging of limestone pores. A field scale wetland/anoxic limestone drain (WALD) system located at Douglas, WV exported net alkaline water (mean of 127 mg/L as CaCO{sub 3}) for one year. However, dissolved oxygen and Fe data suggest that poor hydraulic conductivity caused this system to act as an Fe-oxidizing system, rather than an Fe-reducing system. As such, the system's long term effectiveness for treating AMD was compromised. After five years of operation, the system still reduces the acidity of the water from about 500 mg/L as CaCO{sub 3} to about 150 mg/L. A small scale Greenhouse system performed more like an Fe-reducing system, decreasing acidity for seven months and exporting Fe{sup 2+}, although the water existing the wetland did not contain excess alkalinity. While complications arose in the authors systems due to high flows in the Douglas system and high acidity in the Greenhouse system, pre-treating AMD with organic material can improve the condition of the water for proper treatment by an ALD or underlying limestone. For low to moderate flows (<400 L/min) and low Fe concentrations (<50 mg/L), a passive system that pre-treats AMD with organic substrates and then directs the water into limestone may be effective for many

  12. The Significance of Podpe limestone in the Cultural Heritage of Slovenia

    NASA Astrophysics Data System (ADS)

    Kramar, Sabina; Bedjanič, Mojca; Mirtič, Breda; Mladenović, Ana; Rožič, Boštjan; Skaberne, Dragomir; Zupančič, Nina

    2013-04-01

    Podpeč limestone is characterized by its dark grey, or nearly black colour, with white fossil shells of the Lithiotis. These beds, which have been dated as Lower Jurassic, occur in southern and south-western Slovenia, and are particularly common in areas southwest of Ljubljana. The main quarry, which is not active, is located next to the village of Podpeč near Ljubljana, and has been declared as a geological natural value of national importance; as such, it is officially protected as a natural monument. In the close vicinity of the village there are some other smaller quarries, but all of them have been abandoned. With its very low porosity (0.9%) and water absorption (0.13 - 0.30 % by mass), but relatively high compressive strength (185 MPa), this limestone is quite durable, although its colouring becomes somewhat bleached when situated outdoors. The use of Podpeč limestone was first documented in the case of the Roman period in Slovenia, when it was used for funerary stelae, votive altars, boundary stones, and other artefacts. At the end of the 5th Century AD, with the fall of the Roman Empire, stone-cutting ceased at Podpeč for the next few centuries. Before 1850 Podpeč limestone had no special value. Only very few portals or pilasters made of this stone are known, and no evidence has been found in churches. However, towards the end of the 19th Century Podpeč limestone became better-known, although before the first half of the 20th Century there were no significant stonecutting workshops in Podpeč. After this, stone was supplied progressively from the main quarry. Large numbers of buildings in Ljubljana and central Slovenia have sills, lintels and jambs made of Podpeč limestone. Production stopped in 1967. The internationally renowned Slovenian architect Jože Plečnik (1872-1957) used Podpeč limestone in various Slovenian buildings - the central stadium in Ljubljana, the National University Library, many altars and churches (Bogojina, the Ši\\vska and

  13. Actinobacterial diversity in limestone deposit sites in Hundung, Manipur (India) and their antimicrobial activities

    PubMed Central

    Nimaichand, Salam; Devi, Asem Mipeshwaree; Tamreihao, K.; Ningthoujam, Debananda S.; Li, Wen-Jun

    2015-01-01

    Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected to 16S rRNA gene sequencing. Generic diversity of the limestone isolates consisted of Streptomyces (15 phylotypic groups), Micromonospora (4), Amycolatopsis (3), Arthrobacter (3), Kitasatospora (2), Janibacter (1), Nocardia (1), Pseudonocardia (1) and Rhodococcus (1). Considering the antimicrobial potential of these actinobacteria, 19 showed antimicrobial activities against at least one of the bacterial and candidal test pathogens, while 45 exhibit biocontrol activities against at least one of the rice fungal pathogens. Out of the 137 actinobacterial isolates, 118 were found to have at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, NRPS). The results indicate that 86% of the strains isolated from Hundung limestone deposit sites possessed biosynthetic gene clusters of which 40% exhibited antimicrobial activities. It can, therefore, be concluded that limestone habitat is a promising source for search of novel secondary metabolites. PMID:25999937

  14. Dietary adaptations of Assamese macaques (Macaca assamensis) in limestone forests in Southwest China.

    PubMed

    Huang, Zhonghao; Huang, Chengming; Tang, Chuangbin; Huang, Libin; Tang, Huaxing; Ma, Guangzhi; Zhou, Qihai

    2015-02-01

    Limestone hills are an unusual habitat for primates, prompting them to evolve specific behavioral adaptations to the component karst habitat. From September 2012 to August 2013, we collected data on the diet of one group of Assamese macaques living in limestone forests at Nonggang National Nature Reserve, Guangxi Province, China, using instantaneous scan sampling. Assamese macaques were primarily folivorous, young leaves accounting for 75.5% and mature leaves an additional 1.8% of their diet. In contrast, fruit accounted for only 20.1%. The young leaves of Bonia saxatilis, a shrubby, karst-endemic bamboo that is superabundant in limestone hills, comprised the bulk of the average monthly diet. Moreover, macaques consumed significantly more bamboo leaves during the season when the availability of fruit declined, suggesting that bamboo leaves are an important fallback food for Assamese macaques in limestone forests. In addition, diet composition varied seasonally. The monkeys consumed significantly more fruit and fewer young leaves in the fruit-rich season than in the fruit-lean season. Fruit consumption was positively correlated with fruit availability, indicating that fruit is a preferred food for Assamese macaques. Of seventy-eight food species, only nine contributed >0.5% of the annual diet, and together these nine foods accounted for 90.7% of the annual diet. Our results suggest that bamboo consumption represents a key factor in the Assamese macaque's dietary adaptation to limestone habitat.

  15. Depositional facies and diagenetic history of Trenton Limestone in northern Indiana

    SciTech Connect

    Fara, D.R.; Keith, B.D.

    1984-12-01

    Subsurface cores were studied petrographically to determine the facies and diagenetic history of the Trenton Limestone on a regional scale in northern Indiana. The Trenton Limestone is a yellowish olive-gray fossiliferous limestone, which is replaced by a light-gray dolostone in northern Indiana. Facies composing the Trenton are: 1) bryozoan-echinoderm packstone, 2) bryozoan-echinoderm grainstone, 3) bryozoan packstone to wackestone, 4) lime mudstone, and 5) dolostone. The bryozoan-echinoderm packstone is the major facies. Coarse-grained (1-4 mm) grainstones are typically 1 ft (30 cm) thick, have abrupt bases, and become muddy upward. They are considered storm deposits. Hardgrounds occur throughout the limestone facies, but they are most numerous toward the base. These facies indicate deposition below wave base, interrupted by periods of high energy during storms. Fossiliferous white and gray chert nodules are scattered throughout the unit. Also found in the limestone facies are prevalent stylolites and microstylolites, an indication of chemical compaction. The dolostone facies consists of coarsely crystalline (0.4 mm) idiotopic dolomite. Pyrite is associated with the dolomite. Porosity, found only in the dolostone, is discontinuous and characterized as intercrystalline, vuggy, and moldic. Porous zones are commonly oil stained or have been plugged by poikilotopic selentic gypsum. Minor amounts of celestite are found as cavity fillings.

  16. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W.

    1996-12-31

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  17. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect

    Grover, P.W. )

    1996-01-01

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  18. Effect of magnesium salts on the sulphation capacity of limestone slurry

    SciTech Connect

    Ozyuguran, A.; Altun-Ciftcioglu, G.; Karatepe, N.; Ersoy-Mericboyu, A.

    2006-09-15

    The effect of different magnesium salts such as MgO, MgSO{sub 4}.7H{sub 2}O and Mg(OH){sub 2} on the total sulphation capacities of limestone slurries prepared from five different limestone samples was investigated. Sulphation reactions of slurries were conducted at a constant temperature of 323 K in a gaseous mixture consisting of 5% O{sub 2}, 10% CO{sub 2}, 0.5% SO{sub 2} and a balance of nitrogen by volume. It was found that the total sulphation capacities of limestone slurries increased with the addition of MgO and Mg(OH){sub 2} salts and decreased with the addition of MgSO{sub 4}.7H{sub 2}O salt. Depending on the chemical composition of the limestone samples the total sulphation capacities of limestone slurries were increased between 22.30% and 75.00% by MgO addition and between 23.70% and 69.00% by Mg(OH){sub 2} addition.

  19. Discrimination of reservoir dolostone within tight limestone using rock physics modeling and pre-stack parameters

    NASA Astrophysics Data System (ADS)

    Park, G.; Lee, B.; Lee, G.

    2013-12-01

    Dolostones may be differentiated from limestones based on various pre-stack seismic parameters as they are denser and faster. However, because the seismic properties of a rock are affected strongly by porosity, porous dolostones may not be significantly denser and faster than limestones. We computed various pre-stack parameters (P-impedance, S-impedance, Vp/Vs, Poisson's ratio, Lamé constants) for tight limestones using the Vp and density logs from a well that penetrated Jurassic carbonate and the Vs log, constructed from the empirical relationships of Vp and Vs. The pre-stack parameters of dolostones with 1% - 40% porosity were estimated based on the bulk and shear moduli and bulk densities computed from the formulas proposed by various workers, including Gassmann equations. Crossplots of the pre-stack parameters show that the Lamé constants (λ, μ) are most effective in differentiating dolostones from limestones. In particular, the λρ -μρ vs. μρ crossplot shows a clear-cut separation of the porous dolostones and tight limestones; the porous dolostones plot exclusively to the left of the λρ -μρ of about 25 GPa.

  20. [Effect of limestone and magnesite application on remediation of acidified forest soil in Chongqing, China].

    PubMed

    Yang, Yong-sen; Duan, Lei; Jin, Teng; Zhao, Da-wei; Zhang, Dong-bao; Hao, Ji-ming

    2006-09-01

    Effect of limestone and magnesite application on remediation of a typical acidified soil under a masson pine (Pinus massoniana) forest at Tieshanping, Chongqing in southwest China was studied through field experiments. The changes of soil water chemistry in different layers within one year after application of limestone or magnesite indicated that the remediation agents leaded to the recovery of acidified soil by significant increase of pH value and concentration of relative cation, i.e., Ca2+ or Mg2+, and notable decrease of inorganic monomeric aluminum (Ali). However, the accelerated leaching of NO3- and SO4(2-) might somewhat counteract the positive effects. Since the limestone powder applied was much finer and thus more soluble than the magnesite powder, it seemed that the addition of limestone was more effective than that of magnesite. However, the application of magnesite could probably improve the nutrient uptake and growth of plant, and thus limestone and magnesite should be used together. The change of soil water chemistry was much more notable in upper layer of soil than lower, which means that it will take long time to achieve the whole profile soil remediation.

  1. Fluoride removal from groundwater by limestone treatment in presence of phosphoric acid.

    PubMed

    Gogoi, Sweety; Nath, Suresh K; Bordoloi, Shreemoyee; Dutta, Robin K

    2015-04-01

    Fluoride removal from groundwater has been studied by addition of dilute phosphoric acid (PA) to the influent water before limestone treatment through laboratory plug-flow column experiments and bench-scale plug-flow pilot tests. In this PA-enhanced limestone defluoridation (PAELD) technique, fluoride is removed from 0.526 mM to 0.50-52.60 μM in 3 h with near neutral final pH. The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05. The estimated recurring cost is US$ ≈0.58/m(3) water. Simple scrubbing and rinsing is a preferable method for regeneration of limestone as it is almost equally effective with lime or NaOH. Sorption of fluoride by calcium phosphates produced in situ in the reactor is the dominant mechanism of fluoride removal in the PAELD. Precipitation of CaF2 and sorption of fluoride by the limestone also contribute to the fluoride removal. High efficiency, capacity, safety, environment-friendliness, low cost and simplicity of operation make the PAELD a potential technique for rural application. PMID:25621387

  2. The effects of lichen cover upon the rate of solutional weathering of limestone

    NASA Astrophysics Data System (ADS)

    McIlroy de la Rosa, J. P.; Warke, P. A.; Smith, B. J.

    2014-09-01

    The contribution of lichens to the biomodification of limestone surfaces is an area of conflict within bioweathering studies, with some researchers suggesting a protective effect induced by lichen coverage and others a deteriorative effect induced by the same organisms. Data are reported demonstrating the potential role of endolithic lichen, in particular of Bagliettoa baldensis, in the active protection of Carboniferous limestone surfaces from rainfall-induced solutional weathering. During a 12-month microcatchment exposure period in the west of Northern Ireland, average dissolutional losses of calcium are greater from a lichen-free limestone surface compared with a predominantly endolithic lichen-covered surface by just under 1.25 times. During colder winter months, the lichen-free surface experiences calcium loss almost 1.5 times greater than the lichen-covered surface. Using extrapolation to upscale from the micro-catchment sample scale, for the year of sample exposure, the rate of calcium loss is 1.001 g m- 2 a- 1 from lichen-covered limestone surfaces and 1.228 g m- 2 a- 1 from lichen-free bare limestone surfaces. This research has implications for our understanding of karst environments, the contribution of lichens to karren development and the conservation of lichen-colonised dimension stone within a cultural setting.

  3. [Effect of limestone and magnesite application on remediation of acidified forest soil in Chongqing, China].

    PubMed

    Yang, Yong-sen; Duan, Lei; Jin, Teng; Zhao, Da-wei; Zhang, Dong-bao; Hao, Ji-ming

    2006-09-01

    Effect of limestone and magnesite application on remediation of a typical acidified soil under a masson pine (Pinus massoniana) forest at Tieshanping, Chongqing in southwest China was studied through field experiments. The changes of soil water chemistry in different layers within one year after application of limestone or magnesite indicated that the remediation agents leaded to the recovery of acidified soil by significant increase of pH value and concentration of relative cation, i.e., Ca2+ or Mg2+, and notable decrease of inorganic monomeric aluminum (Ali). However, the accelerated leaching of NO3- and SO4(2-) might somewhat counteract the positive effects. Since the limestone powder applied was much finer and thus more soluble than the magnesite powder, it seemed that the addition of limestone was more effective than that of magnesite. However, the application of magnesite could probably improve the nutrient uptake and growth of plant, and thus limestone and magnesite should be used together. The change of soil water chemistry was much more notable in upper layer of soil than lower, which means that it will take long time to achieve the whole profile soil remediation. PMID:17117649

  4. Tidal rhythmites infine-grained Carboniferous limestones, U.S.A.

    USGS Publications Warehouse

    Archer, A.W.; Feldman, H.R.

    1994-01-01

    Analyses of fine-grained limestones reveals that many exhibit fine-scale laminations. Laminations can be normally graded and consist of a coarser-grained lower part and a finer-grained upper part. The upper part can also contain finely disseminated organic material. Despite the similarities of such graded laminae to yearly varves and turbidites, it can be demonstrated by use of laminae-thickness periodicities that some graded laminae are reasonably interpreted as the product of tidal processes. Within siliciclastic systems, modern analogues of such processes are available for comparisons. In fine-grained facies of the Salem Limestone (Visean; Indiana, U.S.A.), periodicities observed within sequential-laminae thicknesses indicate a dominant control by neap-spring tidal processes. Similarly, laminae within limestones of the vertebrate-bearing Hamilton paleochannel (Stephanian; Kansas, U.S.) exhibit similar features, including fine-scale tidal bundles. This limestone is noted for the abundance of articulated fish fossils. Carbonates containing articulated fish from the Wild Cow Formation (Stephanian; New Mexico, U.S.), exhibit diffuse laminations; however, closely associated siliciclastic mudstones contain laminae that exhibit tidal periodicities. There are many similarities between tidal periodicities and patterns of lamination thicknesses of these rocks. A tidal interpretation for these rocks allows for localized, very rapid rates of deposition. Such rapid deposition may, in part, help to explain how articulated fish and other vertebrates can become preserved within such fine-grained limestones. ?? 1994.

  5. Fluoride removal from groundwater by limestone treatment in presence of phosphoric acid.

    PubMed

    Gogoi, Sweety; Nath, Suresh K; Bordoloi, Shreemoyee; Dutta, Robin K

    2015-04-01

    Fluoride removal from groundwater has been studied by addition of dilute phosphoric acid (PA) to the influent water before limestone treatment through laboratory plug-flow column experiments and bench-scale plug-flow pilot tests. In this PA-enhanced limestone defluoridation (PAELD) technique, fluoride is removed from 0.526 mM to 0.50-52.60 μM in 3 h with near neutral final pH. The presence of PA increases the fluoride removal capacity of limestone to 1.10 mg/g compared to 0.39 mg/g reported in its absence. The changes in fluoride removal with variation in initial PA concentration, initial fluoride concentration and the final pH have been found to be statistically significant with p < 0.05. The estimated recurring cost is US$ ≈0.58/m(3) water. Simple scrubbing and rinsing is a preferable method for regeneration of limestone as it is almost equally effective with lime or NaOH. Sorption of fluoride by calcium phosphates produced in situ in the reactor is the dominant mechanism of fluoride removal in the PAELD. Precipitation of CaF2 and sorption of fluoride by the limestone also contribute to the fluoride removal. High efficiency, capacity, safety, environment-friendliness, low cost and simplicity of operation make the PAELD a potential technique for rural application.

  6. Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA

    SciTech Connect

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

  7. Porosity development in the Copper Ridge Dolomite and Maynardville Limestone, Bear Creek Valley and Chestnut Ridge, Tennessee

    SciTech Connect

    Goldstrand, P.M.; Menefee, L.S.; Dreier, R.B.

    1995-12-01

    Matrix porosity data from deep core obtained in Bear Creek Valley indicate that porosities in the Maynardville Limestone are lithology and depth dependent. Matrix porosities are greater in the Cooper Ridge Dolomite than in the Maynardville Limestone, yet there is no apparent correlation with depth. Two interrelated diagenetic processes are the major controlling factors on porosity development in the Copper Ridge Dolomite and Maynardville Limestone; dissolution of evaporate minerals and dedolomitization. Both of these diagenetic processes produce matrix porosities between 2.1 and 1.3% in the Copper Ridge Dolomite and upper part of the Maynardville Limestone (Zone 6) to depths of approximately 600 ft bgs. Mean matrix porosities in Zones 5 through 2 of the Maynardville Limestone range from 0.8 to 0.5%. A large number of cavities have been intersected during drilling activities in nearly all zones of the Maynardville Limestone in Bear Creek Valley. Therefore, any maynardville Limestone zone within approximately 200 ft of the ground surface is likely to contain cavities that allow significant and rapid flow of groundwater. Zone 6 could be an important stratigraphic unit in the Maynardville Limestone for groundwater flow and contaminant transport because of the abundance of vuggy and moldic porosities. There are large variations in the thickness and lithology in the lower part of the Maynardville (Zones 2, 3, and 4 in the Burial Grounds region). The direction and velocity of strike-parallel groundwater flow may be altered in this area within the lower Maynardville Limestone.

  8. Dry Mouth (Xerostomia)

    MedlinePlus

    ... Gum Disease TMJ Disorders Oral Cancer Dry Mouth Burning Mouth Tooth Decay See All Oral Complications of Systemic ... mouth trouble chewing, swallowing, tasting, or speaking a burning feeling in the mouth a dry feeling in the throat cracked lips ...

  9. Dry Skin (Xerosis)

    MedlinePlus

    ... skin, which may bleed if severe. Chapped or cracked lips. When dry skin cracks, germs can get ... cause the skin to become dry, raw, and cracked. Swimming : Some pools have high levels of chlorine, ...

  10. Beam Injection into RHIC

    NASA Astrophysics Data System (ADS)

    Fischer, W.; Hahn, H.; Mackay, W. W.; Tsoupas, N.

    1997-05-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. We describe the injection zone and its bottlenecks, the application program to steer the beam and the injection kickers. We report on the commissioning of the injection systems and on measurements of the kickers.

  11. Use of borehole radar reflection logging to monitor steam-enhanced remediation in fractured limestone-results of numerical modelling and a field experiment

    USGS Publications Warehouse

    Gregoire, C.; Joesten, P.K.; Lane, J.W.

    2006-01-01

    Ground penetrating radar is an efficient geophysical method for the detection and location of fractures and fracture zones in electrically resistive rocks. In this study, the use of down-hole (borehole) radar reflection logs to monitor the injection of steam in fractured rocks was tested as part of a field-scale, steam-enhanced remediation pilot study conducted at a fractured limestone quarry contaminated with chlorinated hydrocarbons at the former Loring Air Force Base, Limestone, Maine, USA. In support of the pilot study, borehole radar reflection logs were collected three times (before, during, and near the end of steam injection) using broadband 100 MHz electric dipole antennas. Numerical modelling was performed to predict the effect of heating on radar-frequency electromagnetic (EM) wave velocity, attenuation, and fracture reflectivity. The modelling results indicate that EM wave velocity and attenuation change substantially if heating increases the electrical conductivity of the limestone matrix. Furthermore, the net effect of heat-induced variations in fracture-fluid dielectric properties on average medium velocity is insignificant because the expected total fracture porosity is low. In contrast, changes in fracture fluid electrical conductivity can have a significant effect on EM wave attenuation and fracture reflectivity. Total replacement of water by steam in a fracture decreases fracture reflectivity of a factor of 10 and induces a change in reflected wave polarity. Based on the numerical modelling results, a reflection amplitude analysis method was developed to delineate fractures where steam has displaced water. Radar reflection logs collected during the three acquisition periods were analysed in the frequency domain to determine if steam had replaced water in the fractures (after normalizing the logs to compensate for differences in antenna performance between logging runs). Analysis of the radar reflection logs from a borehole where the temperature

  12. Weight losses of marble and limestone briquettes exposed to outdoor environments in the eastern United States

    SciTech Connect

    Reimann, K.J.

    1991-09-01

    Gravimetric changes in marble and limestone briquettes exposed to outdoor environment at five sites in the eastern United States have been monitored since 1984. An earlier report describes procedures and results obtained in 1984--1988. This report presents the results of the exposure period 1984--1988 and reviews and summarizes those of prior years. A linear relationship was found between cumulative gravimetric losses and exposure period or rain depth. These losses resulted in an average recession rate of 14 to 24 {mu}m/yr for marble and twice that for limestone. Variations in recession among the various exposure sites can be ascribed to differences in rain depth and hydrogen ion concentration. The annual recession rates obtained from gravimetry yielded rates that were for marble twice those obtained from runoff experiments, and more than three times those for limestone; this indicates that physical erosion plays an important role. Gravimetric monitoring of exposed briquettes is continuing in a planned 10-yr program.

  13. Freshwater biodissolution rates of limestone in the temperate climate of the Dinaric karst in Slovenia

    NASA Astrophysics Data System (ADS)

    Mulec, J.; Prelovšek, M.

    2015-01-01

    Dissolution rates in two freshwater karst systems were determined by using tablets of dense micrite-biopelmicrite Cretaceous limestone. Submerged limestone tablets in riverbeds were subjected to a natural gradient from complete darkness to direct sunlight. Higher light rates significantly (p < 0.05) increased the epilithic biomass of phototrophs and the overall dissolution rates, which were highest at the Unica spring (- 49.2 μm a- 1), but the exact portion of light-dependent dissolution remains elusive. In the karst river Unica, with its big fluctuations in environmental parameters (e.g., discharge), light rates can be used in estimating the dissolution rates enhanced by phototrophs. Natural biofilms in aquatic systems have important implications for landform evolution, and the impact on limestone dissolution rates is comparable with rates of debris falling from steep slopes.

  14. Search for high-calcium limestone in Silurian reefs of northern Indiana.

    USGS Publications Warehouse

    Ault, C.H.; Carr, D.D.

    1981-01-01

    During Silurian time, the Indiana part of the Wabash Platform was a shallow-water area between the proto-Illinois and proto- Michigan Basins and a site of growth of hundreds, or perhaps thousands, of reefs. Today, most reefs of northern Indiana are dolomite, but some are dolomitic limestone, and a few are limestone of high purity in deposits that can be mined by openpit methods. Four of the five generations of reefs of Silurian age in the Great Lakes area have been recognized in northern Indiana. All known limestone reefs are restricted to an area of six countries in north-central Indiana, although no apparent depositional environment as revealed from study of surrounding inter-reef rocks has been found to account for any restriction. Dolomitization is more likely related to the textures and lithologies of the individual reefs.-from Authors

  15. Chitinozoans in the Ordovician (Caradocian) Ridley and Pierce Limestones of central Tennessee

    SciTech Connect

    Kessler, T.E.; Siesser, W.G. )

    1990-04-01

    Chitinozoans are an extinct group of organic microfossils of uncertain biological affinity. In shape, they resemble minute (50{mu}m-2,000{mu}m) flasks and vases. Chitinozoan fossils occur in marine sedimentary rocks ranging from Cambrian to Carboniferous in age. Chitinozoan diversity is low in the Ridley and Pierce Limestones. Thirteen taxa were identified; two were left in open nomenclature, and one (Conochitina ridleyensis) is provisionally considered to be a new species. Low chitinozoan abundance and the sporadic distribution of chitinozoans in the Ridley and Pierce Limestones is believed to be the result of variable environmental conditions associated with a marine, shallow-shelf environment. The short-ranging chitinozoan taxa Lagenochitina baltica, Conochitina robusta, and Rhabdochitina turgida allow an accurate age assignment to be made for the Ridley and Pierce Limestones. These formations can now be correlated with the Conochitina hirsuta-Lagenochitina sp. A biozone, indicating an upper Blackriveran (mid-Caradocian) age assignment.

  16. Applications of bacterial carbonatogenesis to the protection and regeneration of limestones in buildings and historic patrimony

    NASA Astrophysics Data System (ADS)

    Le Métayer-Levrel, G.; Castanier, S.; Orial, G.; Loubière, J.-F.; Perthuisot, J.-P.

    1999-07-01

    The ability of the so-called carbonatogenic bacteria may be used for producing surficial protecting coatings (biocalcin) on limestones buildings, monuments and statuary. This is the concept of biomineralisation. Laboratory experiments were undertaken in order to choose the most active bacterial strains and to improve the composition of the nutritional media suitable for stimulating the nitrogen cycle metabolic pathways which are the only ones to be used in aerobic and/or microaerophilic conditions. Life-size experiments, subsequent measurements, and observations show that this natural process of biomineralisation is feasible within the frame of industrial constraints. This concept of further developments includes the creation of patinas and the manufacturing of biological mortars and cements which were also improved in the laboratory. The biomineralisation recreates a material that is remarkably similar to the limestone substrate because it uses natural microbial mediation which follows the same natural processes that formed many limestones.

  17. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    NASA Astrophysics Data System (ADS)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

  18. Prediction of Building Limestone Physical and Mechanical Properties by Means of Ultrasonic P-Wave Velocity

    PubMed Central

    Concu, Giovanna; De Nicolo, Barbara; Valdes, Monica

    2014-01-01

    The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulus of elasticity was studied. The effectiveness of ultrasonic velocity was evaluated by regression, with the aim of observing the coefficient of determination r2 between ultrasonic velocity and the aforementioned parameters, and the mathematical expressions of the correlations were found and discussed. The strong relations that were established between ultrasonic velocity and limestone properties indicate that these parameters can be reasonably estimated by means of this nondestructive parameter. This may be of great value in a preliminary phase of the diagnosis and inspection of stone masonry conditions, especially when the possibility of sampling material cores is reduced. PMID:24511286

  19. Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

    PubMed

    McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

    2006-01-01

    Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering. PMID:16391878

  20. Lacustrine sedimentation and origin of the Upper Pennsylvanian Redstone limestone, northern Appalachian basin

    SciTech Connect

    Eggleston, J.R. )

    1993-03-01

    The Redstone limestone occurs in a 7- to 12-m interval between the underlying Pittsburgh and overlying Redstone coal beds. The thickness of the Redstone limestone, which is up to 12 m, varies laterally. The Redstone is sometimes partially or totally replaced by a fluvial siliciclastic unit, which formed either penecontemporaneous or just prior to the limestone. Two cores and an outcrop of Redstone limestone in northern West Virginia were studied in detail. X-ray mineralogical analyses indicate that the limestone is predominantly calcite, ankerite, and quartz, with minor amounts of dolomite, chert, pyrite, feldspar, and clay minerals. Six carbonate facies were identified. The predominant facies is a pedogenic breccia facies that contains typical paleosol features, such as peds and root traces, and represents periods of subaerial exposure of the sediment. A fossiliferous facies contains an abundance of ostracod and mollusk fossilized shells; nested ostracod shells and the occurrence of a shallow-water gastropod, Anthracopupa sp., suggest a shallow-water origin. A bioturbated facies exhibits disrupted bedding and burrows filled with detrital material. The micritic facies contains predominantly calcite and ankerite grains less than 30 microns in diameter and exhibits no apparent bedding. A laminated facies is characterized by two distinct types of lamination: one type is created by interbedding of quartz, clay minerals, plant material, and calcite and/or ankerite and could be caused by periodic storms; the other type contains interbeds of rhombohedral ankerite within predominantly micritic calcite, which could be caused by changes in climate or lake conditions. In summary, petrographic and sedimentological analyses indicate that the Redstone limestone probably formed in a shallow, widespread lake or series of lakes.

  1. Fabrication of sinterable silicon nitride by injection molding

    NASA Technical Reports Server (NTRS)

    Quackenbush, C. L.; French, K.; Neil, J. T.

    1982-01-01

    Transformation of structural ceramics from the laboratory to production requires development of near net shape fabrication techniques which minimize finish grinding. One potential technique for producing large quantities of complex-shaped parts at a low cost, and microstructure of sintered silicon nitride fabricated by injection molding is discussed and compared to data generated from isostatically dry-pressed material. Binder selection methodology, compounding of ceramic and binder components, injection molding techniques, and problems in binder removal are discussed. Strength, oxidation resistance, and microstructure of sintered silicon nitride fabricated by injection molding is discussed and compared to data generated from isostatically dry-pressed material.

  2. A new species of Blaesodactylus (Squamata: Gekkonidae) from Tsingy limestone outcrops in Namoroka National Park, north-western Madagascar.

    PubMed

    Ineich, Ivan; Glaw, Frank; Vences, Miguel

    2016-01-01

    We describe a new gekkonid lizard of the genus Blaesodactylus from Tsingy limestone of a deciduous dry forest of Namoroka National Park, north-western Madagascar. Blaesodactylus victori sp. nov., the sixth recognized species of this genus, is distinguished from all other congeners by its large size and a combination of regular small gular granules, spotted venter, lack of dorsal tubercles, enlarged supranasal scales separated ventrally by a much smaller scale in contact with the rostral, and black naris. The new arboreal species is also characterized by its dark dorso-ventral stripes on the head separating infralabial and most supralabial plates and in life by a typical white spotted pattern on a washed grey to dark grey vermiculated dorsum. Molecular phylogenetic data place the species into a clade with B. boivini and B. microtuberculatus, as sister to a subclade containing these two species. The new species shares some morphological characters states with its African sister genus Homopholis, suggesting that its morphology might be rather plesiomorphic. We also identify several previously overlooked morphological traits characterizing the entire B. boivini clade, possibly also being plesiomorphic. Due to its extremely limited presumed extent of occurrence and continuing decline of its habitat we propose an IUCN Red List status of "Critically Endangered" for the new species.

  3. A new species of Blaesodactylus (Squamata: Gekkonidae) from Tsingy limestone outcrops in Namoroka National Park, north-western Madagascar.

    PubMed

    Ineich, Ivan; Glaw, Frank; Vences, Miguel

    2016-01-01

    We describe a new gekkonid lizard of the genus Blaesodactylus from Tsingy limestone of a deciduous dry forest of Namoroka National Park, north-western Madagascar. Blaesodactylus victori sp. nov., the sixth recognized species of this genus, is distinguished from all other congeners by its large size and a combination of regular small gular granules, spotted venter, lack of dorsal tubercles, enlarged supranasal scales separated ventrally by a much smaller scale in contact with the rostral, and black naris. The new arboreal species is also characterized by its dark dorso-ventral stripes on the head separating infralabial and most supralabial plates and in life by a typical white spotted pattern on a washed grey to dark grey vermiculated dorsum. Molecular phylogenetic data place the species into a clade with B. boivini and B. microtuberculatus, as sister to a subclade containing these two species. The new species shares some morphological characters states with its African sister genus Homopholis, suggesting that its morphology might be rather plesiomorphic. We also identify several previously overlooked morphological traits characterizing the entire B. boivini clade, possibly also being plesiomorphic. Due to its extremely limited presumed extent of occurrence and continuing decline of its habitat we propose an IUCN Red List status of "Critically Endangered" for the new species. PMID:27394884

  4. Rapid method to determine actinides and 89/90Sr in limestone and marble samples

    DOE PAGES

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; Utsey, Robin C.; Sudowe, Ralf; McAlister, Daniel R.

    2016-04-12

    A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and 89/90Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. Lastly, this approach has a sample preparation time for limestone and marble samples of <4 hours.

  5. Passive treatment of acid mine drainage in down-flow limestone systems

    SciTech Connect

    Watzlaf, G.R.

    1997-12-31

    Passive down-flow systems, consisting of compost and/or limestone layers, may be well suited for treatment of acidic mine drainage containing ferric iron and/or aluminum. Two columns were constructed and operated in the laboratory. The first column simulated a downward, vertical-flow anaerobic wetland, also referred to as successive alkalinity-producing systems (SAPS), and has received mine drainage for 97 weeks. The 0.16-m diameter column was vertically oriented and (from bottom to top) consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost, and 0.91 m of free standing water. Water flowed vertically downward through the system. A second column, filled with only limestone, received water from the same source as the first column. This limestone column contained a 1.06-m thick layer of limestone and 0.91 m of free standing water and has received water for 55 weeks. Actual acid mine drainage (pH = 3.1, acidity = 200 mg/L (as CaCO{sub 3}), SO{sub 4}{sup 2-} = 600 mg/L, Total Fe = 10 mg/L, Mn = 14 mg/L, and Al = 18 mg/L) was collected every two weeks from a nearby abandoned deep mine and applied to these columns at a rate of 3.8 mL/min. For the compost/limestone column, effluent pH remained above 6.2 (6.2-7.9); however, pH at a depth of 0.38 m in the compost (halfway) dropped to < 4 after 28 weeks (net acidic). At the bottom of the compost pH remained > 4.5 for all 97 weeks. Alkalinity was generated by a combination of limestone dissolution and sulfate reduction. Over the 97 week period, the column generated an average of 330 mg/L of alkalinity, mostly due to limestone dissolution. Bacterial sulfate reduction displayed an ever decreasing trend, initially accounting for more than 200 mg/L of alkalinity and after 40 weeks only accounting for about 50 mg/L.

  6. Accelerated weathering of limestone for CO2 mitigation: Opportunities for the stone and cement industries

    USGS Publications Warehouse

    Langer, William H.; San, Juan A.; Rau, Greg H.; Caldeira, Ken

    2009-01-01

    Accelerated weathering of limestone appears to provide a low-tech, inexpensive, high-capacity, environmentally friendly CO2 mitigation method that could be applied to about 200 fossil fuel fired power plants and about eight cement plants located in coastal areas in the conterminous U.S. This approach could also help solve the problem of disposal of limestone waste fines in the crushed stone industry. Research and implementation of this technology will require new collaborative efforts among the crushed stone and cement industries, electric utilities, and the science and engineering communities.

  7. Discrimination of moist oil shale and limestone using laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Paris, P.; Piip, K.; Lepp, A.; Lissovski, A.; Aints, M.; Laan, M.

    2015-05-01

    Laser-induced plasma emission spectra of Estonian oil shale and associated limestone with varying moisture content were studied. Time gated spectra excited by 1064 nm laser radiation were recorded. Spectral lines for determination of plasma parameters were selected. Moisture causes the reduction of the intensity of the total emission, and increases the intensity of the Hα line. It was found that the effect of the moisture content on the plasma temperature and electron concentration was inconsiderable. Using the ratio of intensities of Hα and Mg spectral lines, it was possible to distinguish reliably between limestone and oil shale independently of their moisture content.

  8. Reducing Energy-Related CO2 Emissions Using Accelerated Limestone Weathering

    SciTech Connect

    Rau, G H; Knauss, K G; Langer, W H; Caldeira, K

    2004-04-27

    Following earlier descriptions, the use and impacts of accelerated weathering of limestone AWL; reaction: CO{sub 2} + H{sub 2}O + CaCO{sub 3} {yields} Ca{sup 2+} + 2(HCO{sub 3}{sup -}) as a CO{sub 2} capture and sequestration method is further explored. Since ready access to the ocean is likely an essential requirement for AWL, it is shown that significant limestone resources are relatively close to a majority of CO{sub 2}-emitting power plants along the coastal US. Furthermore, waste fines, representing more than 20% of current US crushed limestone production (>10{sup 9} tonnes/yr), could be used in many instances as an inexpensive or free source of AWL carbonate. With limestone transportation to coastal sites then as the dominant cost variable, CO{sub 2} sequestration (plus capture) costs of $3-$4/tonne are achievable in certain locations. While there is vastly more limestone and water on earth than that required for AWL to capture and sequester all fossil fuel CO{sub 2} production, the transportation cost of bringing limestone, seawater, and waste CO{sub 2} into contact likely limits the method's applicability to perhaps 10-20% of US point-source emissions. Using a bench-scale laboratory reactor, it is shown that CO{sub 2} sequestration rates of 10{sup -6} to 10{sup -5} moles/sec per m{sup 2} of limestone surface area are readily achievable using seawater. This translates into reaction densities as high as 2 x 10{sup -2} tonnes CO{sub 2} m{sup -3}day{sup -1}, highly dependent on limestone particle size, solution turbulence and flow, and CO{sub 2} concentration. Modeling of AWL end-solution disposal in the ocean shows significantly reduced effects on ocean pH and carbonate chemistry relative to those caused by direct CO{sub 2} disposal into the atmosphere or ocean. In fact the increase in ocean Ca{sup 2+} and bicarbonate offered by AWL should significantly enhance the growth of corals and other marine calcifiers whose health is currently being threatened by

  9. Basalt-Limestone and Andesite-Limestone Interaction in the Arc Crust - Implications for Volcanic Degassing of CO2

    NASA Astrophysics Data System (ADS)

    Carter, L. B.; Dasgupta, R.

    2014-12-01

    Volcanically emitted CO2 is generally mantle-derived, but high degassing rates at some arcs (e.g. Merapi [1] and Colli Albani Volcanic District [2]) are thought to be affected by magma-carbonate interaction in the upper plate. However, the effects of depth, temperature, and composition on this process are poorly known. We experimentally simulated magma (50%)-limestone (50%) wallrock interactions at 0.5-1.0 GPa, 1100-1200 °C using pure calcite and a hydrous (~3-5 wt.% H2O) melt (basalt, andesite, or dacite). At 1.0 GPa, 1200 °C starting melts are superliquidus, whereas in the presence of calcite, Ca-rich cpx ± Ca-scapolite are produced. With increasing T, basalt-calcite interaction causes the melt, on a volatile-free basis, to become silica-poor and Ca-rich with alumina decreasing as cpx becomes more CaTs-rich. The same trend is seen with all starting melt compositions as P decreases at a constant T (1200 °C), producing melts similar to ultracalcic (CaO/Al2O3>>1) melt inclusions found in arc settings. Shifting from basalt to andesite has little effect on SiO2 and CaO of the reacted melt (e.g. 37 wt.% SiO2, 42 wt.% CaO at 0.5 GPa, 1200 °C), whereas Al2O3 of andesite-derived reacted melt is lower, likely a result of lower alumina in the starting andesite. Wall-rock calcite consumption is observed to increase with increasing T, decreasing P, and increasing melt XSiO2. At 0.5 GPa between 1100 and 1200 °C, our basalt experiments yield carbonate assimilation from 22 to 48 wt.%. This decreases to 20 wt.% at 1.0 GPa, 1200 °C, whereas an andesitic composition assimilates 59 to 52 wt.% from 0.5 to 1.0 GPa at 1200 °C. The higher assimilation in andesite-added runs at high-T is because of lower silicate liquidus as evidenced by lower modal proportion or absence of cpx ± scapolite. Using a magma flux rate estimated for Mt. Vesuvius [3], we obtain a CO2 outflux for a single such volcano experiencing arc magma-calcite reaction [4] of at least 2-4% of the present

  10. Dry building mixture with complex dispersed mineral additives

    NASA Astrophysics Data System (ADS)

    Il'ina, Liliia; Mukhina, Irina; Teplov, Alexandr

    2016-01-01

    The effectiveness of the complex dispersed mineral additive consisting of diopside and limestone was provided by the following factors. Diopside, due to the high hardness, reinforces formed hardened cement paste and prevents the spread of micro-cracks in it under the action of loads. Furthermore, diopside due to the greater elastic modulus than cement paste causes redistribution of stress between the additive particles and the cement. Limestone, since it has chemical affinity with the clinker minerals and products of their hydration hardening, effects on the hydration process and the formation of the contact area between the additive particles and the cement. The optimum quantity of complex dispersed mineral additive is 7%. At the same time the strength of the solution, made of dry building mixture "rough leveler for floor", increased by 22.1%, and the strength of the solution, made of dry mortar "masonry mixture" increased by 32.7%. With the mineral additive introduction the offset of the endoeffect temperatures to higher temperatures on derivatograms is fixed. If there is a mineral additive in the hardened cement paste, which may act as substrate for the tumors crystallization, the hardened cement paste structure strengthening while the complex thermal analysis is seen.

  11. Tests for injecting, storing, and recovering freshwater in a saline artesian aquifer, Lee County, Florida

    USGS Publications Warehouse

    Fitzpatrick, D.J.

    1986-01-01

    An investigation was made of the suitability of a saline, artesian limestone aquifer for the injection, storage, and recovery of freshwater from the Caloosahatchee River. The tests were conducted on a well tapping a leaky artesian system that has a transmissivity of 800 square feet per day, a storage of 1 x 10-4, and a leakance of 0.01 per day. The specific capacity of the injection well was increased through acidizing and was decreased as a result of well clogging during injection. Three injection tests were made wherein the amounts of freshwater injected, the storage duration, and the quality of water injected varied. Analysis of the test data showed that freshwater recoverability ranged from 9.7 to 38.7 percent of the total injected. Differences were attributed principally to differences in the quality of water injected and storage duration. Repeated injection-recovery cycles probably would result in greater recoverability. Head buildup, nearly 200 feet in one test, was a prime problem related chiefly to clogging from suspended material in the injected water and to bacterial growth at the wellbore-limestone interface. Regular backflushing was required. Total head buildup decreased as a result of acidizing the injection well. No coliforms or fecal streptococcus were noted in the recovered water. Growth of anaerobic bacteria occurred. Changes in the quality of the recovered water included decreases in concentration of dissolved organic carbon by as much as 15 mg/L (milligrams per liter), organic nitrogen by as much as 0.80 mg/L, and nitrate by as much as 0.50 mg/L. Increases were noted in ammonia by 0.40 mg/L, and iron by as much as 0.60 mg/L. These changes are consistent with the presence of an anaerobic bacterial ecosystem.

  12. Low temperature dry scrubbing reaction kinetics and mechanisms, Volume 1. Final report, September 1, 1991--August 31, 1992

    SciTech Connect

    Prudich, M.E.; Sampson, K.J.; Reddy, S.N.; Maldei, M.; Ben-Said, L.

    1992-10-01

    Dry scrubbing that takes place after the air preheater (<350{degree}F) is the mode of operation that is of primary interest to this research project. At the relatively low temperatures that occur in this region of operation the rate of the gas-solid reaction that drives SO{sub 2} capture in the convective (800 to 1200{degree}F) and the combustion (1600 to 2400{degree}F) zones is too slow to be significant. The presence of significant amounts of either liquid-phase or vapor-phase water is required in order to mediate SO{sub 2} capture and to produce reasonable capture rates. A mathematical process model describing the cross-flow, moving-bed Limestone Emission Control (LEC) process has been formulated. This process model incorporates the resistance-in-series SO{sub 2} capture kinetic model described in the Project Year {number_sign}1 final report. The kinetic model formulated during Project Year {number_sign}1 pointed to limestone solubility and rate of solubilization as being key factors in determining the rate of SO{sub 2} capture in wetted limestone (LEC) scrubbing systems. In Project Year {number_sign}2, limestone solubilities and rates of solubilization are being determined for a suite of Ohio limestones.

  13. Drilling fluids and lost circulation in hot-dry-rock geothermal wells at Fenton Hill

    SciTech Connect

    Nuckols, E.B.; Miles, D.; Laney, R.; Polk, G.; Friddle, H.; Simpson, G.

    1981-01-01

    Geothermal hot dry rock drilling at Fenton Hill in northern New Mexico encountered problems of catastrophic lost circulation in cavernous areas of limestones in the Sandia Formation, severe corrosion due to temperatures of up to 320/sup 0/C, and torque problems caused by 35/sup 0/ hole angle and the abrasiveness of Precambrian crystalline rock. The use of polymeric flocculated bentonite fluid, clear water, fibrous material, dry drilling, oxygen scavengers, a biodegradable lubricant mixture of modified triglicerides and alcohol, and maintenance of a high pH, were some of the approaches taken toward solving these problems.

  14. 40 CFR 60.2115 - What if I do not use a wet scrubber, fabric filter, activated carbon injection, selective...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... filter, activated carbon injection, selective noncatalytic reduction, an electrostatic precipitator, or a... electrostatic precipitator, or a dry scrubber or limit emissions in some other manner, including material..., fabric filter, activated carbon injection, selective noncatalytic reduction, an...

  15. 40 CFR 60.2115 - What if I do not use a wet scrubber, fabric filter, activated carbon injection, selective...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbon injection, selective noncatalytic reduction, or an electrostatic precipitator to comply with the... carbon injection, selective noncatalytic reduction, fabric filter, or an electrostatic precipitator or... filter, an electrostatic precipitator, or a dry scrubber or limit emissions in some other...

  16. Groundwater Quality Impacts Related to Carbon Dioxide, Brine and Trace Metal Leakage into a Shallow, Unconfined Limestone Aquifer

    NASA Astrophysics Data System (ADS)

    Bacon, D. H.; Hou, Z.; Dai, Z.; Zheng, L.

    2012-12-01

    Accurate prediction of the impact of leaks related to geologic carbon sequestration on groundwater quality is limited by the complexity of subsurface aquifers and the geochemical reactions that control drinking water compositions. As a result, there is a high uncertainty associated with predictions, hampering monitoring plans, interpretation of the monitoring results, and mitigation plans for a given site. As a part of the National Risk Assessment Program (NRAP), funded by the U.S. Department of Energy, a model of the Edwards Aquifer in Texas has been developed to examine the geochemical impacts of leakage of CO2 and brine containing trace metals into an oxidizing unconfined, carbonate aquifer. We use STOMP-CO2-R, which is a multiphase flow simulator, coupled with the reactive transport module ECKEChem, both developed at PNNL, to simulate CO2 sequestration in deep saline formations and the associated reactions with formation minerals. The limestone almost entirely consists of calcite, with lesser amounts of dolomite and trace metals adsorbed on minor amounts of clay and iron oxides. A reduced order model of this more complex chemistry and physics based model has been developed to be included in a framework for quantifying the overall risks associated with CO2 injection, leaks and groundwater impacts. The aquifer model uses reduced-order models, provided by other NRAP groups, of CO2 and brine leakage from wellbores and faults as inputs. Geochemical input parameters were varied to determine parameter sensitivity and to generate a response surface of output variables. The output variables were pH < 6.5 or TDS > 500 ppm plume size and CO2 flux to atmosphere, as well the volume of aquifer with trace metal concentrations greater than their U.S. Environmental Protection Agency Maximum Contaminant Levels. The uncertain input parameters were CO2/brine leak rate, brine composition, mineral surface area and volumetric percent, equilibrium coefficients, and kinetic rates

  17. Oxygen and carbon isotopic composition of limestones and dolomites, bikini and eniwetok atolls.

    PubMed

    Gross, M G; Tracey, J I

    1966-03-01

    Aragonitic, unconsolidated sediments from the borings on the Eniwetok and Bikini atolls are isotopically identical with unaltered skeletal fragments, whereas the recrystallized limestones exhibit isotopic variations resulting from alteration in meteoric waters during periods of emergence. Dolomites and associated calcites are enriched in O(18), perhaps because of interaction with hypersaline brines.

  18. Unconformity-associated replacement limestones after anhydrite in Mississippian of Williston Basin

    SciTech Connect

    Kendall, A.C.

    1983-03-01

    Locally in southeastern Saskatchewan, Mississippian nodular anhydrites (after subaqueous gypsum) beneath an unconformity have been altered to limestone-limestones that are commonly porous and oil-bearing. In the region, carbonates beneath the unconformity are normally overlain by red beds and have been completely dolomitized and plugged with anhydrite to form an impermeable caprock. Mississippian anhydrites subcrop at the unconformity surface and reveal little evidence of alteration-even to gypsum. Textures in replaced anhydrites indicate that calcitization involved both creation of porosity and in-situ (small-scale) replacement leading to retention of anhydrite (and later gypsum) fabrics. Celestite formed as strontium was released from anhydrite during replacement by gypsum and calcite. Sulfur in associated pyrite is isotopically lighter than the anhydrite, suggesting anhydrite-alteration involved the activities of sulfate-reducing bacteria. Evidently, H/sub 2/S liberated during the reaction migrated across the unconformity to reduce overlying red beds. Limestones of this type do not appear to have been reported previously. Stratigraphic and petrographic evidence indicates replacement, although spacially related to the unconformity, was not a weathering phenomenon. It occurred after the unconformity was buried. Unexpectedly heavy delta/sup 13/C and delta/sup 18/O values (+ 1.22 to 1.54, and -1.0 to -3.7) obtained from the replacement limestones seem to preclude the utilization of organic carbon in the reaction. The source of carbonate and of the energy required for sulfate-reducing bacterial activity is therefore problematic.

  19. Lead, zinc, and strontium in limestone cap rock from Tatum salt dome, Mississippi

    SciTech Connect

    Saunders, J.A.

    1988-09-01

    Limestone cap rock at Tatum salt dome, Mississippi, contains disseminated pyrite, sphalerite, and galena, and disseminated to massive amounts of strontianite (SrCO/sub 3/) and celestite (SrSO/sub 4/). Sulfide minerals are locally present in bitumen-rich areas of the upper, massive portion of the limestone cap rock, whereas strontium minerals are disseminated throughout this zone. However, sulfide and strontium minerals are most abundant in the lower banded portion of the limestone cap rock, which consists of alternating subhorizontal light and dark-colored bands. The dark bands are composed of calcite of variable grain size, sulfides, quartz, dolomite, albite, and up to 1% bitumen that apparently formed by the biodegradation of crude oil. Lighter bands are composed of variable amounts of coarsely crystalline, euhedral calcite, strontianite, and celestite resulting in strontium (Sr) contents of up to 30% locally. Banded limestone cap rock at Tatum dome formed at the top of the actively dissolving anhydrite zone by a combination of sulfate reduction and oxidation of liquid hydrocarbons by bacteria to cause the precipitation of calcite and sulfide minerals and the accumulation of insoluble residue from the anhydrite (quartz, albite, dolomite). Lead and zinc in the sulfide minerals could have been derived from the dissolving anhydrite, but the abundance of Sr minerals present requires an external source. Present-day oil field brines in central Mississippi contain up to 3000 ppm Sr, and basin brines of similar composition apparently contributed Sr to the cap-rock environment during formation.

  20. The effect of elevated temperature on the strength parameters of silica acid ester consolidated porous limestones

    NASA Astrophysics Data System (ADS)

    Pápay, Zita; Török, Ákos

    2013-04-01

    The porous limestone is one of the most widespread construction materials of the monuments in Central Europe, with emblematic buildings in Vienna, Bratislava, Budapest and many other cities of Austria, Slovakia, Czech Republic and Hungary. The restoration of these monuments very often requires the consolidation of the porous limestone material, where various types of consolidants are used to strengthen the highly weathered stone. Our research focused on the understanding of the behaviour of consolidated porous limestone when the material is subjected to higher temperatures. Test procedure included the preparation of cylindrical test specimens from the Miocene porous limestone which was followed by consolidation by four various types of silica acid ester. The samples after consolidation were heated to 300 and 600 °C in electric oven. The material properties such as ultrasonic pulse velocity, density were tested before and after the treatment. Indirect tensile strength (Brazilian test) was used to compare the strength parameters of non treated and consolidated samples. Silica acid ester treated samples after heating were also measured in terms of strength, density and ultrasonic pulse velocity. The results show that there are significant changes in strength of various pre-treated samples after heating indicating the sensitivity of the materials to temperature changes and accidental fire.

  1. Hydrogen sulfide capture by limestone and dolomite at elevated pressure. 2: Sorbent particle conversion modeling

    SciTech Connect

    Zevenhoven, C.A.P.; Yrjas, K.P.; Hupa, M.M.

    1996-03-01

    The physical structure of a limestone or dolomite to be used in in-bed sulfur capture in fluidized bed gasifiers has a great impact on the efficiency of sulfur capture and sorbent use. In this study an unreacted shrinking core model with variable effective diffusivity is applied to sulfidation test data from a pressurized thermogravimetric apparatus (P-TGA) for a set of physically and chemically different limestone and dolomite samples. The particle size was 250--300 {micro}m for all sorbents, which were characterized by chemical composition analysis, particle density measurement, mercury porosimetry, and BET internal surface measurement. Tests were done under typical conditions for a pressurized fluidized-bed gasifier, i.e., 20% CO{sub 2}, 950 C, 20 bar. At these conditions the limestone remains uncalcined, while the dolomite is half-calcined. Additional tests were done at low CO{sub 2} partial pressures, yielding calcined limestone and fully calcined dolomite. The generalized model allows for determination of values for the initial reaction rate and product layer diffusivity.

  2. Performance Monitoring: Evaluating an Organic Carbon-Limestone PRB for Treatment of Heavy Metals and Acidity

    EPA Science Inventory

    Since 2004, researchers from the U.S. EPA National Risk Management Research Laboratory (NRMRL) have annually evaluated performance of an organic carbon-limestone permeable reactive barrier (PRB) system installed in 2003 by EPA Region 6 at the Delatte Metals Superfund site in Ponc...

  3. Limestone characterization to model damage from acidic precipitation: Effect of pore structure on mass transfer

    USGS Publications Warehouse

    Leith, S.D.; Reddy, M.M.; Irez, W.F.; Heymans, M.J.

    1996-01-01

    The pore structure of Salem limestone is investigated, and conclusions regarding the effect of the pore geometry on modeling moisture and contaminant transport are discussed based on thin section petrography, scanning electron microscopy, mercury intrusion porosimetry, and nitrogen adsorption analyses. These investigations are compared to and shown to compliment permeability and capillary pressure measurements for this common building stone. Salem limestone exhibits a bimodal pore size distribution in which the larger pores provide routes for convective mass transfer of contaminants into the material and the smaller pores lead to high surface area adsorption and reaction sites. Relative permeability and capillary pressure measurements of the air/water system indicate that Salem limestone exhibits high capillarity end low effective permeability to water. Based on stone characterization, aqueous diffusion and convection are believed to be the primary transport mechanisms for pollutants in this stone. The extent of contaminant accumulation in the stone depends on the mechanism of partitioning between the aqueous and solid phases. The described characterization techniques and modeling approach can be applied to many systems of interest such as acidic damage to limestone, mass transfer of contaminants in concrete and other porous building materials, and modeling pollutant transport in subsurface moisture zones.

  4. Goat Urine and Limestone Affect Nitrogen and Cation Distributions in an Acidic Grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Use of goats (Capra aegagrus hircus L.) to clear overgrown pastures and woodlots of unwanted vegetation may result in high rates of urine deposition where goats congregate. Surface application of limestone to dystrophic acid soils before clearing is known to augment ammonia gas volatilization from ...

  5. Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation

    EPA Science Inventory

    The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

  6. Treatment Of Metal-Mine Effluents By Limestone Neutralization And Calcite Co-Precipitation (Presentation)

    EPA Science Inventory

    The U.S. Geological Survey - Leetown Science Center and the Colorado School of Mines have developed a remediation process for the treatment of metals in circumneutral mining influenced waters. The process involves treatment with a pulsed limestone bed (PLB) system, followed by c...

  7. Hydrology of the cavernous limestones of the Mammoth Cave area, Kentucky

    USGS Publications Warehouse

    Brown, Richmond F.

    1966-01-01

    The Mammoth Cave National Park in central Kentucky offers a unique opportunity to study the occurrence of ground water in limestone under natural conditions. Ground water occurs as perched and semiperched bodies in alternate sandstone, shale, and limestone formations and under water-table conditions at the approximate level of the Green River in thick soluble limestone. Three continuous recorders that operated for 5 years indicate that precipitation on the Mammoth Cave plateau recharges the underlying sandstone rapidly. Ground water from the sandstone discharges horizontally to the edges of the plateau and vertically to underlying formations. Some of the precipitation recharges underlying formations almost immediately through overland flow to sinkholes and free fall through open shafts to pools at the water table. Much of the precipitation on the Pennyroyal plain flows overland into sinkholes and then through solution openings to the Green River. Water from the Green River flows into limestone solution channels under Mammoth Cave plateau at some stages, and this water discharges again to the Green River downstream. The presence of salt water, high in chloride in the Green River, makes it possible to trace the movement of the river water through the underground streams. Graphs show relationships of chloride concentration, stage of the Green River, time, precipitation, ground-water levels, and stratigraphy.

  8. Assessment of radiological hazard of NORM in Margalla Hills limestone, Pakistan.

    PubMed

    Ali, Muhammad; Qureshi, Aziz Ahmed; Waheed, Abdul; Baloch, Muzahir Ali; Qayyum, Hamza; Tufail, Muhammad; Khan, Hameed Ahmed

    2012-08-01

    Studies on naturally occurring radioactive material (NORM) in the limestone from the Margalla Hills have been carried out by measuring gamma activity and to access its radiological implications if any. For data acquisition, a High-Purity Germanium detector was employed. The activity concentrations of (226)Ra, (232)Th, and (40)K were found to be 14.32 ± 0.24, 2.05 ± 0.04, and 13.80 ± 0.20 Bq kg(-1), respectively. These values are relatively lower as compared to that in the limestone of other countries and much lower than the values reported for the natural building stones. The average specific activities due to (226)Ra were found to be higher when compared with (40)K and (232)Th. Indices of radium equivalent activity (Ra(eq)), internal hazard (H(in)), indoor absorbed gamma dose rate (D(R,)), and corresponding annual effective dose (E(eff)) were also determined for the limestone-made rooms. All of these indices were found to be in the lower ranges. The Margalla Hills limestone does not pose any excessive radiological health hazard as a building material and in industrial uses for a common man.

  9. Use of limestone obtained from waste of the mussel cannery industry for the production of mortars

    SciTech Connect

    Ballester, Paloma; Marmol, Isabel; Morales, Julian; Sanchez, Luis . E-mail: luis-sanchez@uco.es

    2007-04-15

    Various types of cement-SiO{sub 2}-CaCO{sub 3} mortar were prepared by replacing quarry limestone aggregate with limestone obtained as a by-product from waste of the mussel cannery industry. The CaCO{sub 3} aggregate consists mainly of elongated prismatic particles less than 4 {mu}m long rather than of the rounded particles of smaller size (2-6 {mu}m) obtained with quarry limestone. The mechanical and structural properties of the mortars were found to be influenced by aggregate morphology. Setting of the different types of mortar after variable curing times was evaluated by scanning electron microscopy (SEM), thermogravimetric analysis (TG) and mercury intrusion porosimetry (MIP) techniques. Mortars with a high content in mussel shell limestone exhibited a more packed microstructure, which facilitates setting of cement and results in improved mortar strength. The enhanced mechanical properties of the new mortars allow the cement content in the final mortar composition to be decreased and production costs to be reduced as a result.

  10. Adsorption/desorption of phosphorus on limestone from the Biscayne Aquifer under freshwater and seawater conditions.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Areas of seawater intrusion are known geochemically active regions particularly in limestone aquifers, where carbonate mineral dissolution and ion exchange reactions are important. Both of these processes can lead to a release of phosphorus from the aquifer matrix to the groundwater as seawater int...

  11. The mechanics of intersecting echelon veins and pressure solution seams in limestone

    NASA Astrophysics Data System (ADS)

    Seyum, Solomon; Pollard, David D.

    2016-08-01

    Many studies that describe the formation of echelon vein arrays relate the causative stresses implicitly to the deformation, reliant on simple shear kinematics, such that the vein-to-array angle and the array width are the primary physical quantities. In contrast, we identify twelve physical quantities to describe echelon veins in two dimensions, including coeval, vein-intersecting, pressure solution seams. A finite element method is used to reproduce vein shapes in linear elastic and elastic-perfectly plastic model limestone. Model vein geometries are designed using values within the range of geometries measured from echelon veins at Raplee Anticline and Comb Monocline, Utah. Four physical quantities are significant for describing echelon vein shapes: vein spacing, vein-array angle, limestone elastic stiffness, and closing of orthogonal pressure solution seams. Pressure solution seam closing influences the mechanical interaction between adjacent veins, and for a range of conditions, causes a nearly linear vein opening distribution (triangular shapes) and encourages straight vein propagation, both of which approximate field measurements. Model results show that small spacing of veins with seams and large vein-array angles promote straight vein traces in limestone with stiffness typical of laboratory measurements, given the physical geologic conditions inferred from the burial history of the limestone strata.

  12. 76 FR 60815 - Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills Training Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    ... Department of the Army Final Legislative Environmental Impact Statement (LEIS) for the Limestone Hills Training Area Land Withdrawal, Montana Army National Guard (MTARNG) AGENCY: National Guard Bureau (NGB), Department of the Army, DoD. ACTION: Notice of availability. SUMMARY: This announces the availability of...

  13. Alteration of limestone surfaces in an acid rain environment by gas-solid reaction mechanisms

    SciTech Connect

    Mossotti, V.G.; Lindsay, J.R.; Hochella, M.F. Jr.

    1987-01-01

    As part of a study to assess mineralogical alterations in building stone due to acid rain, Salem Limestone was exposed in the form of briquettes for one year in several urban and one rural environment. Samples exposed in the rural location were found to be chemically indistinguishable from the freshly quarried limestone (control material). In marked contrast, all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were unwashed by precipitation. However, the bulk chemistry of the urban samples (not including the stain) was virtually identical to the that of the control stone. X-ray photoelectron spectroscopy (XPS) revealed the presence of sulfur (in the form of sulfate) disseminated over the calcite grain surfaces to a depth less than 10 nm in the freshly quarried limestone; XPS showed an identical sulfate layer on the calcite grains after the one year exposure period. Mass balance calculations and sulfur isotope patterns indicate that the gypsum stain on the protected surfaces consists of adventitious sulfur. The authors found no evidence of nitrate attack on any of the limestone surfaces.

  14. Optimization of nanolime solvent for the consolidation of coarse porous limestone

    NASA Astrophysics Data System (ADS)

    Borsoi, Giovanni; Lubelli, Barbara; van Hees, Rob; Veiga, Rosário; Silva, António Santos

    2016-09-01

    The potentialities of nanomaterials for application in the field of conservation have been widely investigated in the last two decades. Among nanomaterials, nanolimes, i.e., dispersions of lime nanoparticles in alcohols are promising consolidating products for calcareous materials. Nanolimes are effective in recovering the very superficial loss of cohesion of decayed materials, but they do not always provide sufficient mass consolidation. This limitation is mainly related to the deposition of the nanoparticles nearby the surface of the material. Experimental research has been set up with the aim of improving the in-depth deposition of lime nanoparticles. Previous research by the authors has shown that nanolime deposition within a substrate can be controlled by adapting the nanolimes properties (kinetic stability and evaporation rate) to the moisture transport behavior of the substrate. Nanolime properties can be modified by the use of different solvents. In this research, nanolime dispersions have been further optimized for application on Maastricht limestone, a coarse porous limestone. Firstly, nanolimes were synthesized and dispersed in ethanol and/or water, both pure and mixed in different percentages. Subsequently, based on the kinetic stability of the nanolime dispersions, the most promising solvent mixtures were selected and applied on the limestone. The deposition of lime nanoparticles within the limestone was studied by phenolphthalein test, optical microscopy and scanning electron microscopy. The results confirm that nanolime dispersed in a mixture of ethanol (95 %) and water (5 %) can guarantee a better nanoparticles in-depth deposition within coarse porous substrates, when compared to dispersions in pure ethanol.

  15. Sulfate Attack of Cement-Based Material with Limestone Filler Exposed to Different Environments

    NASA Astrophysics Data System (ADS)

    Gao, Xiaojian; Ma, Baoguo; Yang, Yingzi; Su, Anshuang

    2008-08-01

    Mortar prisms made with OPC cement plus 30% mass of limestone filler were stored in various sulfate solutions at different temperatures for periods of up to 1 year, the visual appearance was inspected at intervals, and the flexural and compressive strength development with immersion time was measured according to the Chinese standard GB/T17671-1999. Samples were selected from the surface of prisms after 1 year immersion and examined by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), laser-raman spectroscopy and scanning electron microscopy (SEM). The results show that MgSO4 solution is more aggressive than Na2SO4 solution, and Mg2+ ions reinforce the thaumasite sulfate attack on the limestone filler cement mortars. The increase of solution temperature accelerates both magnesium attack and sulfate attack on the limestone filler cement mortar, and leads to more deleterious products including gypsum, ettringite and brucite formed on the surface of mortars after 1 year storage in sulfate solutions. Thaumasite forms in the mortars containing limestone filler after exposure to sulfate solutions at both 5 °C and 20 °C. It reveals that the thaumasite form of sulfate attack is not limited to low-temperature conditions.

  16. Demonstration of a hydration process for reactivating partially sulfated limestone sorbents

    SciTech Connect

    Smith, G.W.; Hajicek, D.R.; Myles, K.M.; Goblirsch, G.M.; Mowry, R.W.; Teats, F.G.

    1981-10-01

    The utilization of limestione sorbent for the removal of SO/sub 2/ in coal combustion in an atmospheric fluidized-bed combustor (AFBC) can be markedly increased by reactivating the partially sulfated limestone for reuse in the combustor. Such reuse would reduce costs and the environmental impact of quarrying and disposing of large quantities of limestone. The reactivation process consists of hydrating the partially sulfated limestone by treatment with water. A demonstration of the hydration process and the reuse of the reactivated limestone were carried out at Grand Forks Energy Technology Center (GFETC) in cooperation with Argonne National Laboratory (ANL). The data obtained in the GFETC 0.2-m/sup 2/ AFBC are compared with those obtained earlier in the ANL 0.02-m/sup 2/ AFBC. Marked enhancement of calcium utilization was achieved in both studies, but differences were noted in the degree of enhancement and in the Ca/S mole ratios required to maintain SO/sub 2/ in the off-gas at an acceptable level.

  17. Laboratory studies of Miocene limestone for the use of construction industry in Sri Lanka

    NASA Astrophysics Data System (ADS)

    de Silva Jayawardena, Upali

    2016-04-01

    Geologically ten percent of Sri Lanka is made up of Miocene limestone which covers northern and north-western coastal belt of the Island. It is used as a raw material for various industries but only cement and lime are being used for the construction industry. Except its chemical composition there is no available literature to study about other properties. Therefore the author carried out a series of laboratory tests to find out the mechanical properties of limestone in Sri Lanka. The objective of this paper is to make a note on the various properties of Miocene limestone and describe its suitability to use as an aggregate for the construction industry in Sri Lanka. Borehole samples (NX size) of limestone were obtained from various drilling sites in Northern Province of Sri Lanka and selected samples were prepared for different laboratory tests after visual observations. The tests were carried out according to ASTM Standards at the geotechnical and materials testing laboratories. The number of samples per each test was different. The range (and average result) for each property can be mentioned here as bulk density 2213-2643 (2452) kg/m3, water absorption 2.2-4.5 (1.91)%, porosity 1-15 (6.5)%, specific gravity 2.58-2.68(2.62), ultrasonic pulse velocity P wave 4480-6338 (5668) m/s and S wave 2688-3802 (3400) m/s, uniaxial compressive strength 11-92 (35)MPa, point load strength 1.2-7.1 (3.7)MPa, aggregate impact value, AIV 25-30 (28)%, LAAV 35-38 (36)%, and Brazilian tensile strength 2.1-4.4 (3.2)MPa. Poisson's ratio 0.12-0.68 (0.22) and modulus of elasticity 42-85 (62) GPa were obtained by using P and S ultrasonic wave velocity values. According to LAAV and AIV this limestone may be suitable as the base course material for road construction but may not be suitable for surface material of highways and rail road ballasts. Ultrasonic velocity waves indicate that limestone is highly compacted and solid. According to the compressive strength of solid limestone rock a few

  18. The Öland limestone - A Swedish stone used for more than one thousand years

    NASA Astrophysics Data System (ADS)

    Schouenborg, Björn; Wickström, Linda; Mikaelsson, Jan

    2016-04-01

    The second largest island in Sweden is the home of the "Öland limestone", a condensed and bedded limestone whose origin dates back to Lower Ordovician, i.e. about 480 M years ago. Öland is a part of the palaeocontinent Baltica that, at the time, was situated at low latitudes with deposition of the calcareous sediments in a cool water environment. The limestone on Öland represents a proximal ramp tectonic setting, with the oldest sediments deposited in the west and younger sediments deposited towards east and southeast. Fluctuating sea-levels have created erosional hard grounds such as the Flowery sheet. These hardgrounds are recognised by their vivid colours and trace fossils, and can be traced all over Baltica, but is maybe best represented on Öland. Ordovician limestones are present in many places in Sweden, but it is the occurrence on Öland that is the most renowned in a building stone perspective. One reason for this is the favourable trading location, an island off the Swedish East coast in middle of the trading routes between the Baltic countries and the continent. Other reasons are the pleasant aesthetical values with numerous orthoceratites and other fossils. The limestones on Öland differ in colour. From the red varieties (with oxidized iron) to brownish and grey. The bedding is mostly in the cm-scale which easily enables very exploitable thickness of slabs. Every mm limestone represents about 1000 years of deposition. The limestone has most likely been used in a very crude way for many thousand years, but archaeological evidence of a more industrialized usage is just a little more than 1000 years. It is known from the literature that the first official Swedish king, Gustav Vasa (16th century), desired this stone. At the time it was called "Öland marble", and the king "imported" specialists to process it further at the Royal Stone workshop on northern Öland. Remnants of tools and working sites still remain in an outdoor museum. Export of the

  19. Slit injection device

    DOEpatents

    Alger, Terry W.; Schlitt, Leland G.; Bradley, Laird P.

    1976-06-15

    A laser cavity electron beam injection device provided with a single elongated slit window for passing a suitably shaped electron beam and means for varying the current density of the injected electron beam.

  20. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  1. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  2. Calcitonin Salmon Injection

    MedlinePlus

    Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to ...

  3. Sodium Ferric Gluconate Injection

    MedlinePlus

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  4. Rich catalytic injection

    DOEpatents

    Veninger, Albert

    2008-12-30

    A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

  5. Quantifying and timing of long-term carbonate mobilisation in a limestone aquifer

    NASA Astrophysics Data System (ADS)

    Kirstein, J.; Gaupp, R.

    2012-04-01

    Carbonate dissolution during weathering, its intermediate storage by reprecipitation, and/or final export to the sea are major components in the global carbon cycle. The Thuringian Basin in the central part of Germany exposes deposits of the German Triassic Muschelkalk sequence consisting of limestone and dolostone beds. Partial dissolution, oxidation and iron redistribution is obvious in limestones along the slopes of the middle Saale river valley. These features are most prominent close to a Mid Quaternary valley floor (Elster terrace). They decrease down-section following fractures in homogeneous micritic limestones of the Lower Muschelkalk (Jena Formation), and reach a minimum close to the present groundwater table. It implies a discontinuous vertical migration of the groundwater table close to the valley slopes, spanning >700 ka of valley incision, and a coeval increase of oxidative weathering of sulfides and organic matter in the micritic carbonate. The recharging groundwater carries dissolved and particulate organic matter from the soil into fractures and pores. Microbial community oxidizes the organic material by using O2 that diffuses in from atmosphere. Due to the dissolved CO2 the water is undersaturated concerning carbonate minerals. The fissures enlarge by the water dissolving the limestones. The working hypothesis suggests the maximum of carbonate dissolution and descendant export within the vadose zone. Material export is supposed to occur dependant on climatic variations with microbial mediation in both dissolution and transient reprecipitation. Furthermore, the study area has the important advantage that the timing of the 100 m migration of the ground water table has a good age control due to topographic dating of terrace formation. Key aspects of this study are the quantification of long-term telodiagenetic transformations of the limestones, the timing of the involved processes and the analysis of current carbon fluxes both surface and subsurface

  6. Evolution and extinction of Permian fusulinid fauna in the Khao Tham Yai Limestone in NE Thailand

    NASA Astrophysics Data System (ADS)

    Hada, Shigeki; Khosithanont, Somboon; Goto, Hiroya; Fontaine, Henri; Salyapongse, Sirot

    2015-05-01

    The first detailed biostratigraphic investigation of a single limestone unit within the Khao Tham Yai Limestone shows it was deposited continuously in a shelf setting without any intercalation of clastic beds. It ranges from the Wordian (middle Middle Permian) up to the Wuchiapingian (lower Upper Permian). The limestone unit is divided in ascending order into three fusulinid zones, i.e. Colania, Lepidolina and Codonofusiella zones. The middle zone is characterized by an abundance of large-tested fusulinids characteristic of the Lepidolina Zone. Shell sizes of the fusulinid species in this zone display continuous rapid morphological change along a one-way evolutionary path from small, primitive species with simple structure to large, highly evolved species having a complicated wall structure. Fusulinid biostratigraphy in a single limestone unit elucidates evolution and extinction patterns of Permian fusulinids of the shallow-water Tethyan shelf area in the Indochina Block. Our study reveals that the boundary between the Guadalupian (Middle Permian) and Lopingian (Upper Permian) in the Khao Tham Yai Limestone is clearly defined as an abrupt change in the fusulinid assemblages from the elimination of large-tested Verbeekinids and Schwagerinids to the domination of small-shelled Schubertellids. The Schubertellids underwent slower evolutionary morphological change than earlier fusulinids and were decreasingly dominant through the Permian. A similar pattern of fusulinid evolution and extinction at the Guadalupian-Lopingian boundary occurs in shallow-water Tethyan shelf areas and mid-oceanic shallow-water environments in mid-Panthalassa. Eventually, even smaller fusulinids abruptly become extinct. Clastic deposits finally replace previous carbonate formations characterized by algae-foraminifera biota. It starts in the upper Middle Permian in the southern parts and spreads throughout the whole area in the lower Upper Permian in NE Thailand. These observations suggest

  7. Evaluation of Different Modeling Approaches to Simulate Contaminant Transport in a Fractured Limestone Aquifer

    NASA Astrophysics Data System (ADS)

    Mosthaf, K.; Rosenberg, L.; Balbarini, N.; Broholm, M. M.; Bjerg, P. L.; Binning, P. J.

    2014-12-01

    It is important to understand the fate and transport of contaminants in limestone aquifers because they are a major drinking water resource. This is challenging because they are highly heterogeneous; with micro-porous grains, flint inclusions, and being heavily fractured. Several modeling approaches have been developed to describe contaminant transport in fractured media, such as the discrete fracture (with various fracture geometries), equivalent porous media (with and without anisotropy), and dual porosity models. However, these modeling concepts are not well tested for limestone geologies. Given available field data and model purpose, this paper therefore aims to develop, examine and compare modeling approaches for transport of contaminants in fractured limestone aquifers. The model comparison was conducted for a contaminated site in Denmark, where a plume of a dissolved contaminant (PCE) has migrated through a fractured limestone aquifer. Multilevel monitoring wells have been installed at the site and available data includes information on spill history, extent of contamination, geology and hydrogeology. To describe the geology and fracture network, data from borehole logs was combined with an analysis of heterogeneities and fractures from a nearby excavation (analog site). Methods for translating the geological information and fracture mapping into each of the model concepts were examined. Each model was compared with available field data, considering both model fit and measures of model suitability. An analysis of model parameter identifiability and sensitivity is presented. Results show that there is considerable difference between modeling approaches, and that it is important to identify the right one for the actual scale and model purpose. A challenge in the use of field data is the determination of relevant hydraulic properties and interpretation of aqueous and solid phase contaminant concentration sampling data. Traditional water sampling has a bias

  8. The effect of limestone treatments on the rate of acid generation from pyritic mine gangue.

    PubMed

    Burt, R A; Caruccio, F T

    1986-09-01

    Surface water enters the Haile Gold Mine, Lancaster County, South Carolina by means of a small stream and is ponded behind a dam and in an abandoned pit. This water is affected by acidic drainage. In spite of the large exposures of potentially acid producing pyritic rock, the flux of acid to the water is relatively low. Nevertheless, the resulting pH values of the mine water are low (around 3.5) due to negligible buffering capacity. In view of the observed low release of acidity, the potential for acid drainage abatement by limestone ameliorants appears feasible.This study investigated the effects of limestone treatment on acid generation rates of the Haile mine pyritic rocks through a series of leaching experiments. Below a critical alkalinity threshold value, solutions of dissolved limestone were found consistently to accelerate the rate of pyrite oxidation by varying degrees. The oxidation rates were further accelerated by admixing solid limestone with the pyritic rock. However, after a period of about a month, the pyrite oxidation rate of the admixed samples declined to a level lower than that of untreated pyrite. Leachates produced by the pyrite and limestone mixtures contained little if any iron. Further, in the mixtures, an alteration of the pyrite surface was apparent.The observed behaviour of the treated pyrite appears to be related to the immersion of the pyrite grains within a high alkalinity/high pH environment. The high pH increases the rate of oxidation of ferrous iron which results in a higher concentration of ferric iron at the pyrite surface. This, in turn, increases the rate of pyrite oxidation. Above a threshold alkalinity value, the precipitation of hydrous iron oxides at the pyrite surface eventually outpaces acid generation and coats the pyrite surface, retarding the rate of pyrite oxidation. PMID:24214013

  9. Ambient Dried Aerogels

    NASA Technical Reports Server (NTRS)

    Jones, Steven M.; Paik, Jong-Ah

    2013-01-01

    A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.

  10. Dephosphorization when using DRI

    SciTech Connect

    2005-09-21

    The increase in high quality steel production in electric arc furnaces (EAFs) requires the use of scrap substitute materials, such as Direct Reduced Iron (DRI) and Hot Briquetted Iron (HBI). Although DRI and HBI products have lower copper and nickel contents than most scrap materials, they can contain up to ten times more phosphorus. This project, led by Carnegie Mellon University’s Center for Iron and Steelmaking Research, improves the understanding of how phosphorus behaves when DRI and HBI melt.

  11. Beam injection into RHIC

    SciTech Connect

    Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

    1997-07-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

  12. To Dry Or Not To Dry

    ERIC Educational Resources Information Center

    Oaks, Audrey E.

    1977-01-01

    Perhaps one of the most frustrating problems which confront many teachers is lack of adequate drying space or facilities for prints, paintings and three-dimensional art activities. Suggests requirements necessary for an adequate storage unit and how to construct one. (Author/RK)

  13. Strategies for safe injections.

    PubMed Central

    Battersby, A.; Feilden, R.; Stoeckel, P.; Da Silva, A.; Nelson, C.; Bass, A.

    1999-01-01

    In 1998, faced with growing international concern, WHO set out an approach for achieving injection safety that encompassed all elements from patients' expectations and doctors' prescribing habits to waste disposal. This article follows that lead and describes the implications of the approach for two injection technologies: sterilizable and disposable. It argues that focusing on any single technology diverts attention from the more fundamental need for health services to develop their own comprehensive strategies for safe injections. National health authorities will only be able to ensure that injections are administered safely if they take an approach that encompasses the whole system, and choose injection technologies that fit their circumstances. PMID:10680247

  14. Tray Drying of Solids.

    ERIC Educational Resources Information Center

    Afacan, Artin; Masliyah, Jacob

    1984-01-01

    Describes a drying experiment useful in presenting the concept of simultaneous heat and mass transfer. Background information, equipment requirements, experimental procedures, and results are provided. The reasonably good agreement in the calculated rate of drying and that observed experimentally makes students feel confident in applying…

  15. Packaged kiln dried firewood

    SciTech Connect

    Cutrara, A.

    1986-07-01

    A process is described for kiln drying firewood consisting of essentially uniform lengths of split firewood pieces, the process comprising splitting essentially uniform lengths of green tree logs to form firewood pieces, placing the firewood pieces in open mesh bags to provide a plurality of bags of firewood, placing the plurality of bags of green firewood pieces in a kiln drying oven, kiln drying the pieces at temperatures in excess of 150/sup 0/F. by moving heated air over the pieces until the pieces have an overall moisture content ranging from 15% up to 30% by weight, operating the kiln at a temperature below a level which would render the structural characteristics of the bag useless and removing the kiln dried firewood pieces in the plurality of bags from the kiln drying oven.

  16. Dry imaging cameras

    PubMed Central

    Indrajit, IK; Alam, Aftab; Sahni, Hirdesh; Bhatia, Mukul; Sahu, Samaresh

    2011-01-01

    Dry imaging cameras are important hard copy devices in radiology. Using dry imaging camera, multiformat images of digital modalities in radiology are created from a sealed unit of unexposed films. The functioning of a modern dry camera, involves a blend of concurrent processes, in areas of diverse sciences like computers, mechanics, thermal, optics, electricity and radiography. Broadly, hard copy devices are classified as laser and non laser based technology. When compared with the working knowledge and technical awareness of different modalities in radiology, the understanding of a dry imaging camera is often superficial and neglected. To fill this void, this article outlines the key features of a modern dry camera and its important issues that impact radiology workflow. PMID:21799589

  17. Passive treatment of acid mine drainage in systems containing compost and limestone: Laboratory and field results

    SciTech Connect

    Watzlaf, G.R.; Pappas, D.M.

    1996-12-31

    Passive, down-flow systems, consisting of compost and limestone layers, termed successive alkalinity producing systems (SAPS), may be well suited for treatment of mine drainage containing ferric iron and/or aluminum. A column, simulating a SAPS, has been operated in the laboratory for 52 weeks. The 0.16-m diameter column consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost thick layer of limestone, a 0.76-m thick layer of spent mushroom compost and 0.91 m of free standing water. Actual AMD (pH = 3.02, acidity = 218 mg/L (as CaCO{sub 3}), SO{sub 4} = 600 mg/L, Fe = 16.0 mg/L, Mn = 12.1 mg/L, and Al = 17.1 mg/L) was applied to the column at a rate of 3.8 mL/min. Effluent pH has remained above 6.2 (6.2-7.9) in the column system. A SAPS located in Jefferson County, PA has been monitored for the past 4.5 years. The SAPS has an approximate area of 1000 m{sup 2} and contains a 0.4-m thick layer of limestone, a 0.2-m thick layer of spent mushroom compost, and 1.5 m of free standing water. Mine water (acidity = 335 mg/L (as CaCO{sub 3}), SO{sub 4} = 1270 mg/L, Fe = 246 mg/L, Mn = 38.4 mg/L, and Al = <0.2 mg/L) flowed into the SAPS at a rate of 140 L/min. Water samples from the field and laboratory systems have been collected at strategic locations on a regular basis and analyzed for pH, alkalinity, acidity, Fe{sup 2+}, total Fe, Mn, Al, SO{sub 4}, Ca, Mg, Na, Co, Ni, and Zn. Alkalinity has been generated in both field and laboratory systems by a combination of limestone dissolution and sulfate reduction. The column generated an average of 378 mg/L of alkalinity; 74% due to limestone dissolution and 26% due to bacterial reduction of sulfate. The field SAPS generated an average of 231 mg/L of alkalinity and exhibited seasonal trends.

  18. Cretaceous planktic foraminiferal biostratigraphy of the Calera Limestone, Northern California, USA

    USGS Publications Warehouse

    Sliter, W.V.

    1999-01-01

    The Calera Limestone is the largest, most stratigraphically extensive limestone unit of oceanic character included in the Franciscan Complex of northern California. The aim of this paper is to place the Calera Limestone at its type locality (Rockaway Beach, Pacifica) in a high-resolution biostratigraphy utilizing planktic foraminifers studied in thin section. A section, about 110 m-thick, was measured from the middle thrust slice exposed by quarrying on the southwest side of Calera Hill at Pacifica Quarry. Lithologically, the section is divided in two units; a lower unit with 73 m of black to dark-grey limestone, black chert and tuff, and an upper unit with 36.8 m of light-grey limestone and medium-grey chert. Two prominent black-shale layers rich in organic carbon occur 11 m below the top of the lower black unit and at the boundary with overlying light-grey unit, yielding a total organic content (TOC) of 4.7% and 1.8% t.w., respectively. The fossiliferous Calera Limestone section measured at Pacifica Quarry, from the lower black shale, contains eleven zones and three subzones that span approximately 26 m.y. from the early Aptian to the late Cenomanian. The zones indentified range from the Globigerinelloides blowi Zone to the Dicarinella algeriana Subzone of the Rotalipora cushmani Zone. Within this biostratigraphic interval, the Ticinella bejaouaensis and Hedbergella planispira Zones at the Aptian/Albian boundary are missing as are the Rotalipora subticinensis Subzone of the Biticinella breggiensis Zone and the overlying Rotalipora ticinensis Zone in the late Albian owing both to low-angle thrust faulting and to unconformities. The abundance and preservation of planktic foraminifers are poor in the lower part and improve only within the upper G. algerianus Zone. The faunal relationship indicate that the lower black shale occurs in the upper part of the G. blowi Zone and correlates with the Selli Event recognized at global scale in the early Aptian. The upper black

  19. Laboratory Investigations in Support of Carbon Dioxide-Limestone Sequestration in the Ocean

    SciTech Connect

    Dan Golomb; Eugene Barry; David Ryan; Stephen Pennell; Peter Swett; Huishan Duan; Michael Woods

    2006-04-01

    This semi-annual progress reports includes further findings on CO{sub 2}-in-Water emulsions stabilized by fine particles of limestone (CaCO{sub 3}). Specifically, here we report on the tests performed in the DOE National Energy Technology Laboratory High Pressure Water Tunnel Facility (HPWTF) using a Kenics-type static mixer for the formation of a CO{sub 2}-H{sub 2}O emulsion stabilized by fine particles of CaCO{sub 3}. The tested static mixer has an ID of 0.5 cm, length 23.5 cm, number of baffles 27. Under pressure, a slurry of CaCO{sub 3} particles (mean particle size 6 {micro}m) in reverse osmosis (RO) water and liquid CO{sub 2} were co-injected into the mixer. From the mixer, the resulting emulsion flowed into the HPWTF, which was filled with RO water kept at 6.8 MPa pressure and 4, 8 or 12 C. The emulsion plume was photographed by three video cameras through spy windows mounted on the wall of the HPWTF. The mixer produced an emulsion consisting of tiny CO{sub 2} droplets sheathed with a layer of CaCO{sub 3} particles dispersed in water. The sheathed droplets are called globules. The globules diameter was measured to be in the 300-500 {micro}m range. The globules were sinking in the HPWTF, indicating that they are heavier than the ambient water. The tests in the HPWTF confirmed that the Kenics-type static mixer is an efficient device for forming a CO{sub 2}-H{sub 2}O emulsion stabilized by fine particles of CaCO{sub 3}. The static mixer may prove to be a practical device for sequestering large quantities of CO{sub 2} in the deep ocean in the form of a CO{sub 2}-H{sub 2}O-CaCO{sub 3} emulsion. The static mixer can be mounted at the end of pipelines feeding the mixer. The static mixer has no moving parts. The pressure drop across the mixer that is necessary to sustain good mixing is created by the hydrostatic pressure of liquid CO{sub 2} and the slurry of CaCO{sub 3} in the pipes that feed the mixer. The tests in the HPWTF demonstrated that the emulsion plume is

  20. Epidural injections for back pain

    MedlinePlus

    ESI; Spinal injection for back pain; Back pain injection; Steroid injection - epidural; Steroid injection - back ... pillow under your stomach. If this position causes pain, you either sit up or lie on your ...

  1. Ultrasonic Drying Processing Chamber

    NASA Astrophysics Data System (ADS)

    Acosta, V.; Bon, J.; Riera, E.; Pinto, A.

    The design of a high intensity ultrasonic chamber for drying process was investigated. The acoustic pressure distribution in the ultrasonic drying chamber was simulated solving linear elastic models with attenuation for the acoustic-structure interaction. Together with the government equations, the selection of appropriate boundary conditions, mesh refinement, and configuration parameters of the calculation methods, which is of great importance to simulate adequately the process, were considered. Numerical solution, applying the finite element method (FEM), of acoustic-structure interactions involves to couple structural and fluid elements (with different degrees of freedom), whose solution implies several problems of hardware requirements and software configuration, which were solved. To design the drying chamber, the influence of the directivity of the drying open camera and the staggered reflectors over the acoustic pressure distribution was analyzed. Furthermore, to optimize the influence of the acoustic energy on the drying process, the average value of the acoustic energy distribution in the drying chamber was studied. This would determine the adequate position of the food samples to be dried. For this purpose, the acoustic power absorbed by the samples will be analyzed in later studies.

  2. LASIK and dry eye.

    PubMed

    Toda, Ikuko

    2007-01-01

    Dry eye is one of the most common complications after laser-assisted in situ keratomileusis (LASIK). The clinical signs of post-LASIK dry eye include positive vital staining of ocular surface, decreased tear film breakup time and Schirmer test, reduced corneal sensitivity, and decreased functional visual acuity. The symptoms and signs last at least 1 month after LASIK. Although the mechanisms for developing post-LASIK dry eye are not completely understood, loss of corneal innervation by flap-making may affect the reflex loops of the corneal-lacrimal gland, corneal-blinking, and blinking-meibomian gland, and blinking-meibomian gland, resulting in decreased aqueous and lipid tear secretion and mucin expression. As LASIK enhancement by flap-lifting induces less dry eye symptoms and signs than first surgery, it is suggested that other factors rather than loss of neurotrophic effect may be involved in the mechanisms of post-LASIK dry eye. The treatments of dry eye include artificial tears, topical cyclosporine, hot compress, punctal plugs, and autologous serum eye drops. For patients with severe preoperative dry eye, a combination of punctal plugs and serum eye drops is required to be used before surgery.

  3. A Homoploid Hybrid Between Wild Vigna Species Found in a Limestone Karst.

    PubMed

    Takahashi, Yu; Iseki, Kohtaro; Kitazawa, Kumiko; Muto, Chiaki; Somta, Prakit; Irie, Kenji; Naito, Ken; Tomooka, Norihiko

    2015-01-01

    Genus Vigna comprise several domesticated species including cowpea and mungbean, and diverse wild species. We found an introgressive hybrid population derived from two wild species, Vigna umbellata and Vigna exilis, in Ratchaburi district, Thailand. The hybrid was morphologically similar to V. umbellata but habituated in a limestone rock mountain, which is usually dominated by V. exilis. Analyzing simple sequence repeat loci indicated the hybrid has undergone at least one round of backcross by V. umbellata. We found the hybrid acquired vigorous growth from V. umbellata and drought tolerance plus early flowering from V. exilis, and thus has taken over some habitats of V. exilis in limestone karsts. Given the wide crossability of V. umbellata, the hybrid can be a valuable genetic resource to improve drought tolerance of some domesticated species. PMID:26648953

  4. On the role of organic adlayers in the anomalous water sorptivity of Lépine limestone.

    PubMed

    Ioannou, Ioannis; Hoff, William D; Hall, Christopher

    2004-11-01

    Sorptivity data are reported for the capillary absorption of water, ethanol, propan-2-ol, and n-heptane by the calcitic limestone Lépine (Lavoux à grain). The data confirm that the water sorptivity is anomalously low, an indication of partial wetting by water. Results are expressed in terms of a wetting index. The water sorptivity increases after heat treatment and chemical oxidation by hydrogen peroxide bleaching, while the sorptivity with organic liquids is unchanged. These treatments, therefore, increase the water wetting index. The results provide strong evidence that the presence of a natural organic adlayer is responsible for the anomalously low water sorptivity of this particular limestone. This natural water repellency effect may be exploited in developing chemical treatments to modify the water transport properties of stone. PMID:15380433

  5. Attenuation of stormwater contaminants from highway runoff within unsaturated limestone, Dade County, Florida

    USGS Publications Warehouse

    Waller, Bradley G.; Klein, Howard; Lefkoff, Lawrence J.

    1984-01-01

    Infiltration of stormwater in heavily urbanized parts of Dade County, Florida, is a prime source of recharge to the unconfined Biscayne aquifer, the sole source of drinking water for southeast Florida. Ponded stormwater at the test site contained greater concentrations of lead, zinc, manganese, nitrogen (except nitrate), and phosphorus than the water which percolated through the unsaturated limestone. Attenuation of some stormwater contaminants in the surface soils and limestone is indicated at the test site adjacent to a busy throughfare. Lead concentrations of 610 micrograms per kilogram and zinc concentrations of 91 micrograms per kilogram were found in the thin surface soils, nearly 20 times more than the concentrations of these metals at greater depth. In contrast, soil and rock sample at a control site remote from heavy traffic contained low concentrations of metals and showed little variation in concentration with depth. (USGS)

  6. Microstructural study of sulfate attack on ordinary and limestone Portland cements at ambient temperature

    SciTech Connect

    Irassar, E.F.; Bonavetti, V.L.; Gonzalez, M

    2003-01-01

    This paper presents an investigation on the mechanism of sulfate attack on Portland cements (PCs) containing limestone filler. It is based on the analysis of microstructure and composition of mortar specimens (ASTM C 1012) stored for 2 years in sodium sulfate solution (0.352 M). Microstructure was studied using quantitative X-ray diffraction (XRD) on samples taken from the surface to the core of the specimens. The profile of compounds formed by sulfate attack was determined millimeter by millimeter at 1 and 2 years. Results show that sulfate attack in mortars containing limestone filler is characterized by an inward movement of the reaction front leading first to the formation of ettringite, later to gypsum deposition, and finally to thaumasite formation when the decalcification of mortar leads to the breakdown of C-S-H.

  7. Water in the Elizabethtown area; a study of a limestone terrane in North Central Kentucky

    USGS Publications Warehouse

    Lambert, T.W.

    1979-01-01

    An inventory of the water resources of a 240-square-mile area in north-central Kentucky is reported. It includes water distribution, chemical quality, water use, and principles of water occurrence and availability, and references. Nolin River is the only major stream in the area. Two of its tributaries, Valley Creek and North Fork Nolin River, have water withdrawn for public supply by Elizabethtown and Hodgenville. The quality of the water from the streams is typical of a limestone terrane. Ground water is also used for public supplies by Elizabethtown and Hodgenville and by two industrial plants. Many springs have flows of more than 0.25 cubic foot per second. Except for stock water, only three springs serve as a water source. Water from wells and springs is typical of limestone terrane. (USGS)

  8. A Novel Treatment for Acid Mine Drainage Utilizing Reclaimed Limestone Residual

    SciTech Connect

    Horace K. Moo-Young; Charles E. Ochola

    2004-08-31

    The viability of utilizing Reclaimed Limestone Residual (RLR) to remediate Acid Mine Drainage (AMD) was investigated. Physical and chemical characterization of RLR showed that it is composed of various minerals that contain significant quantities of limestone or calcium bearing compounds that can be exploited for acid neutralization. Acid Neutralization Potential (ANP) test results showed that RLR has a neutralization potential of approximately 83% as calcium carbonate (CaCO{sub 3}). Neutralization tests with most of the heavy metals associated with AMD showed removal efficiencies of over 99%. An unexpected benefit of utilizing RLR was the removal of hexavalent chromium Cr (VI) from the aqueous phase. Due to an elevation in pH by RLR most AMD heavy metals are removed from solution by precipitation as their metal hydroxides. Cr (VI) however is not removed by pH elevation and therefore subsequent ongoing tests to elucidate the mechanism responsible for this reaction were conducted.

  9. Analysis of roof and pillar failure associated with weak floor at a limestone mine

    PubMed Central

    Murphy, Michael M.; Ellenberger, John L.; Esterhuizen, Gabriel S.; Miller, Tim

    2016-01-01

    A limestone mine in Ohio has had instability problems that have led to massive roof falls extending to the surface. This study focuses on the role that weak, moisture-sensitive floor has in the instability issues. Previous NIOSH research related to this subject did not include analysis for weak floor or weak bands and recommended that when such issues arise they should be investigated further using a more advanced analysis. Therefore, to further investigate the observed instability occurring on a large scale at the Ohio mine, FLAC3D numerical models were employed to demonstrate the effect that a weak floor has on roof and pillar stability. This case study will provide important information to limestone mine operators regarding the impact of weak floor causing the potential for roof collapse, pillar failure, and subsequent subsidence of the ground surface. PMID:27088041

  10. High-temperature H{sub 2}S-removal processes using limestones

    SciTech Connect

    Cairns, E.J.; Lynn, S.

    1993-09-01

    The process under investigation involves removal of H{sub 2}S from the coal gas by sorption into a moving bed of limestone (or lime) particles. NH{sub 3} in the coal gas will be broken down by catalysis and gasifier fines will be removed by cycloning and by filtration by the moving granular bed. This project focuses on developing the necessary description of the kinetics of the reaction of H{sub 2}S with limestone, and in particular the evolution of the structure of the solid during the course of the reaction. A differential tube quartz reactor system for studying these reactions in the temperature range of interest has been built. Since studies at gasification pressures would require a more expensive apparatus, this study is confined to atmospheric pressure.

  11. A Homoploid Hybrid Between Wild Vigna Species Found in a Limestone Karst

    PubMed Central

    Takahashi, Yu; Iseki, Kohtaro; Kitazawa, Kumiko; Muto, Chiaki; Somta, Prakit; Irie, Kenji; Naito, Ken; Tomooka, Norihiko

    2015-01-01

    Genus Vigna comprise several domesticated species including cowpea and mungbean, and diverse wild species. We found an introgressive hybrid population derived from two wild species, Vigna umbellata and Vigna exilis, in Ratchaburi district, Thailand. The hybrid was morphologically similar to V. umbellata but habituated in a limestone rock mountain, which is usually dominated by V. exilis. Analyzing simple sequence repeat loci indicated the hybrid has undergone at least one round of backcross by V. umbellata. We found the hybrid acquired vigorous growth from V. umbellata and drought tolerance plus early flowering from V. exilis, and thus has taken over some habitats of V. exilis in limestone karsts. Given the wide crossability of V. umbellata, the hybrid can be a valuable genetic resource to improve drought tolerance of some domesticated species. PMID:26648953

  12. An unfortunate injection.

    PubMed

    Shah, Bhavik Sandip; Yarbrough, Chase; Price, Amy; Biswas, Rakesh

    2016-01-01

    Intramuscular injection has been used to administer medications for more than a hundred years. However, despite our profession's long experience with intramuscular administration, preventable complications such as injection nerve palsies are still prevalent in developing countries. Injections account for one-fifth of all traumatic nerve injuries. These injuries largely occur due to indiscriminate use of intramuscular injections for treating common illnesses, frequently by unlicensed or undertrained practitioners administering unnecessary treatment to impoverished patients. The sciatic nerve is the most commonly injured, and frequently the resulting muscle weakness and associated disability are irreversible. This case report includes a video of a patient with foot drop 6 weeks after gluteal intramuscular injection. Such injuries can be prevented by proper awareness and training, the implementation of safer injection techniques, and quality assurance methods. PMID:26931130

  13. Stripping with dry ice

    NASA Astrophysics Data System (ADS)

    Malavallon, Olivier

    1995-04-01

    Mechanical-type stripping using dry ice (solid CO2) consists in blasting particles of dry ice onto the painted surface. This surface can be used alone or in duplex according to type of substrate to be treated. According to operating conditions, three physical mechanisms may be involved when blasting dry ice particles onto a paint system: thermal shock, differential thermal contraction, and mechanical shock. The blast nozzle, nozzle travel speed, blast angle, stripping distance, and compressed air pressure and media flow rate influence the stripping quality and the uniformity and efficiency obtained.

  14. Importance of Radius of Influence and its Estimation in a Limestone Quarry

    NASA Astrophysics Data System (ADS)

    Soni, A. K.; Sahoo, L. K.; Ghosh, U. K.; Khond, M. V.

    2015-04-01

    Limestone mining at Lanjiberna limestone and dolomite quarry has created positive as well negative impacts on ground water. With further deepening of the mine, drawdown trend (negative effect) is observed and at the same time ground water recharge of the order of 4,527.48 m3/day, through mine pits (positive impact) is noticed. The aquifer present in the area is unconfined and mainly consists of weathered quartzite, phyllites, limestone and dolomite. To know the cumulative impact of mining on surroundings, the effective radius of influence (Re) for excavated mine area is calculated as 1,059 m. Here, it may be noted that three `concentric working pits' (Pit No. 2 & 6; Pit no 1 & 3 and Pit No 4 & 5) produces limestone at this mine and the pit-wise radius of influence (Ro) is estimated. Value of Ro for Pit-2 & 6 is 612.14 m; Pit-1 & 3 is 475 m and Pit-4 & 5 is 384.15 m. Its average i.e., Ro (for all three pits, cumulative) is estimated as 490 m. From this typical case study and estimation of Ro and Re values, it is concluded that the maximum and minimum value of overall impact/influence lies in between 0.49 and 1.05 km. These estimated values of `area of influence' are less compared to the whole mine lease area values. Local aquifer, which lies at shallower as well as at deeper depth had behaved consistently with respect to recharge and drawdown conditions. Thus, assessment of Ro and Re is extremely helpful for `integrated mine planning' to achieve targeted production, economically with minimum interruptions.

  15. Condition assessment of a highly porous limestone fortress: damage categories and structural integrity

    NASA Astrophysics Data System (ADS)

    Török, Ákos; Czinder, Balázs; Farkas, Orsolya; Görög, Péter; Kopecskó, Katalin; Lógó, János; Rozgonyi-Boissinot, Nikoletta; Vásárhelyi, Balázs

    2016-04-01

    An emblematic monument the Citadella fortress of Budapest has been studied in details to assess the condition of stone structure. The fortress is a large stone structure of 220 m in length and 60 m in width. The height of the porous limestone walls are in between 12-16 metres. The fortress was completed in 1854 but has been partly rebuilt due to changes in function and war related structural damages. The present paper provides an overview of the lithology, weathering forms and structural condition of the fortress related to a forthcoming restoration-reconstruction project. To assess the condition of stone both on site and laboratory analyses were performed. Lithological varieties were documented. Major identified lithotypes are porous oolitic limestone, less porous bioclastic limestone and fine grained highly porous limestone. To identify wet zones portable moisture meter was applied. Surface strength and weathering grade were also assessed using Schmidt hammer and Duroscop. Decay features were diagnosed and mapped. The most common forms are white weathering crusts, scaling and blistering of crusts as well as granular disintegration. Black weathering crusts were also recognized. Laboratory tests were focused on mechanical properties of stones and on mineralogical and chemical compositional analyses. Small samples of stone were collected and tested by optical microscopy, SEM-EDX, XRD and Thermogravimetric analyses. Laboratory analyses proved that the major salt responsible for the damage of external walls is gypsum, although significant amount of halite and hygroscopic salts were found both on the external walls and in the interior parts of the fortress. During structural analyses displacement of walls, tilting and major amount of cracks were recognized. Loss of material and subsidence also caused problems and at some places unstable wall sections were recognized.

  16. Changes in Zn speciation during soil formation from Zn-rich limestones

    NASA Astrophysics Data System (ADS)

    Jacquat, Olivier; Voegelin, Andreas; Juillot, Farid; Kretzschmar, Ruben

    2009-10-01

    In order to better understand the long-term speciation and fractionation of Zn in soils, we investigated three soils naturally enriched in Zn (237-864 mg/kg Zn) from the weathering of Zn-rich limestones (40-207 mg/kg Zn) using extended X-ray absorption fine structure (EXAFS) spectroscopy and sequential extractions. The analysis of bulk EXAFS spectra by linear combination fitting (LCF) indicated that Zn in the oolitic limestones was mainly present as Zn-containing calcite (at site Dornach), Zn-containing goethite (Gurnigel) and Zn-containing goethite and sphalerite (Liestal). Correspondingly, extraction of the powdered rocks with 1 M NH 4-acetate at pH 6.0 mobilized only minor fractions of Zn from the Gurnigel and Liestal limestones (<30%), but most Zn from the Dornach rock (81%). In the Dornach soil, part of the Zn released from the dissolving limestone was subsequently incorporated into pedogenic hydroxy-interlayered vermiculite (Zn-HIV, ˜30%) and Zn-containing kaolinite (˜30%) and adsorbed or complexed by soil organic and inorganic components (˜40%). The Gurnigel and Liestal soils contained substantial amounts of Zn-containing goethite (˜50%) stemming from the parent rock, smaller amounts (˜20%) of Zn-containing kaolinite (and possibly Zn-HIV), as well as adsorbed or complexed Zn-species (˜30%). In the soil from Liestal, sphalerite was only found in trace amounts, indicating its dissolution during soil formation. In sequential extractions, large percentages of Zn (˜55-85%) were extracted in recalcitrant extraction steps, confirming that Zn-HIV, Zn-containing kaolinite and Zn-containing goethite are highly resistant to weathering. These Zn-bearing phases thus represent long-term hosts for Zn in soils over thousands of years. The capability of these phases to immobilize Zn in heavily contaminated soils may however be limited by their uptake capacity (especially HIV and kaolinite) or their abundance in soil.

  17. The implication of the oxygen isotopic composition of lower Devonian micritic limestone, Oklahoma

    SciTech Connect

    Gao, G. . Dept. of Geological Sciences)

    1992-01-01

    The documented [delta]O-18 values of presumably well preserved lower Devonian marine carbonates are significantly lower than those of post-Devonian carbonates. These have been interpreted to have resulted from either O-18-depleted or hot oceans, relative to post-Devonian oceans. To test these hypotheses, micritic limestones were sampled for oxygen (as well carbon and strontium) isotope analysis from the lower Devonian (Lochkovian) Haragan-Bois d'Arc formations of the Hunton Group, South-Central Oklahoma. Of the 25 analyzed samples, 22 samples are characterized by high [delta]C-13 values and ranging from [minus]1.9[per thousand] to [minus]2.9[per thousand](PDB). These are the highest [delta]C-13 limestones were deposited in a shallow normal marine setting and have both [delta]C-13 values and Sr-87/Sr-86 ratios similar to other lower Devonian carbonates elsewhere, the high [delta]O-18 values of these limestones are unlikely to have originated either from any unusual depositional setting or from diagenetic alteration at low temperatures by O-18- and Sr-87-enriched basinal brines. The high [delta]O-18 values of the Haragan-Bois d'Arc limestones are thus interpreted to represent near-primary signals. The temperatures and [delta]O-18 values of early Devonian seawater can be constrained to have been 25 [+-] 7 C and 0 [+-] 1[per thousand] (SMOW), respectively. This implies that neither O-18 depletion nor high temperatures characterized early Devonian oceans.

  18. The Miocene Nullarbor Limestone, southern Australia; deposition on a vast subtropical epeiric platform

    NASA Astrophysics Data System (ADS)

    O'Connell, Laura G.; James, Noel P.; Bone, Yvonne

    2012-05-01

    The early to middle Miocene Nullarbor Limestone forms the vast, karsted Nullarbor Plain in southern Australia, and may be the most extensive Miocene carbonate deposit described to date. These carbonates were deposited at southern paleolatitudes of ~ 40°S and are interpreted to be subtropical to warm-temperate in character because of the presence of certain genera of tropical coralline algae (rhodoliths and articulated types), large benthic foraminifera, tropical molluscs, zooxanthellate corals, and micrite envelopes. Facies are dominated by skeletal grainstones and floatstones that accumulated in three interpreted paleoenvironments: (1) seagrass banks (upper photic zone), (2) rhodolith pavements (lower photic zone), and (3) open seafloors (lower photic to subphotic zone). A decrease of tropical components from west to east across the platform implies that warm oceanic currents (possibly related to a proto-Leeuwin Current), as well as a period of warm climate (Miocene Climatic Optimum), resulted in subtropical deposition at southern latitudes. The Southern Ocean extended inboard ~ 450 km from the shelf edge during Nullarbor Limestone deposition, but interpreted paleodepths did not extend much below the base of the photic zone. A small slope angle (~ 0.02°) over a wide shelf (~ 300,000 km2) implies deposition on an epeiric platform or epeiric ramp. A Miocene barrier reef was likely coeval with Nullarbor Limestone deposition. Therefore, the inboard portion of the Nullarbor Limestone can be considered part of an extensive back-reef lagoon system on a rimmed epeiric platform, perhaps attaining a size similar to the modern Great Barrier Reef system.

  19. 2. INTERIOR OF SAND DRAINING & DRYING BUILDING WITH DRYING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. INTERIOR OF SAND DRAINING & DRYING BUILDING WITH DRYING BINS TO THE RIGHT, LOOKING SOUTHWEST - Mill "C" Complex, Sand Draining & Drying Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  20. Preparing injectable medicines safely.

    PubMed

    Beaney, Alison M; Black, Anne

    Risks to patients are greater when injectable medicines are prepared in clinical areas (wards, theatres, clinics or even patients' homes), rather than provided in ready-to-use form. This article describes the risks involved in preparing injectable medicines in such areas and outlines key principles to ensure they are prepared safely. It also suggests that high-risk injectable medicines be provided in ready-to-use form, either in house, by pharmacy or by pharmaceutical companies. PMID:22359855

  1. Selected data for wells and test holes used in structure-contour maps of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation in the Black Hills area, South Dakota

    USGS Publications Warehouse

    Carter, J.M.

    1999-01-01

    This report presents selected data on wells and test holes that were used in the construction of structure-contour maps of selected formations that contain major aquifers in the Black Hills area of western South Dakota. Altitudes of the top of the Inyan Kara Group, Minnekahta Limestone, Minnelusa Formation, Madison Limestone, and Deadwood Formation are presented for the wells and test holes presented in this report.

  2. Botulinum toxin injection - larynx

    MedlinePlus

    Injection laryngoplasty; Botox-larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography-guided botulinum toxin treatment; Percutaneous indirect laryngoscopy- ...

  3. A combined complex electrical impedance and acoustic emission study in limestone samples under uniaxial loading

    NASA Astrophysics Data System (ADS)

    Saltas, V.; Fitilis, I.; Vallianatos, F.

    2014-12-01

    In the present work, complex electrical impedance measurements in the frequency range of 10 mHz to 1 MHz were carried out in conjunction with acoustic emission monitoring in limestone samples subjected to linear and stepped-like uniaxial loading, up to ultimate failure. Cole-Cole plots of the complex impedance during the stepped loading of limestone have been used to discriminate the contributions of grains interior, grain boundaries and electrode polarization effects to the overall electrical behavior. The latter is well-described with an equivalent-circuit model which comprises components of constant phase elements and resistances in parallel connection. Electrical conductivity increases upon uniaxial loading giving rise to negative values of effective activation volume. This is a strong experimental evidence for the generation of transient electric signals recorded prior to seismic events and may be attributed to charge transfer (proton conduction) due to cracks generation and propagation as a result of the applied stress. The time-series of ac-conductivity at two distinct frequencies (10 kHz, 200 kHz) during linear loading of limestone samples exhibits a strong correlation with the acoustic emission activity obeying the same general self-similar law for critical phenomena that has been reported for the energy release before materials fracture.

  4. Limestone surfaces in built-up environment as indicators of atmospheric pollution.

    PubMed

    Vella, A J; Camilleri, A; Tabone Adami, J P

    1996-12-01

    The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a 'black particle count' (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO2 and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels. PMID:24194411

  5. Paleomagnetic poles for the Carboniferous Brush Creek limestone and Buffalo siltstone from southwestern Pennsylvania

    NASA Astrophysics Data System (ADS)

    Payne, M. A.; Shulik, S. J.; Donahue, J.; Rollins, H. B.; Schmidt, V. A.

    1981-04-01

    We report partial results of a larger project being undertaken in the Appalachian Basin to determine the character of the geomagnetic field in the Carboniferous. The Brush Creek limestone, which contains abundant terrigenous matter, yields reliable results from three different sites, while the overlying Buffalo siltstone appears at one locality. AF demagnetization curves, IRM acquisition curves, thermomagnetic analysis, and optical reflection microscopy indicate that the remanence carriers are magnetites or titanomagnetites, which are probably primary in origin. Stepwise AF demagnetization reveals that the best demagnetizing fields are 15-20 and 20-30 mT for the limestone and siltstone units, respectively. A total of 93 specimens from 20 samples (oriented hand samples and field-drilled cores) yields a paleopole at S 36.1, W 55.7, with an alpha-95 of 4.2° and a k of 13.1 for the Brush Creek limestone. The Buffalo siltstone paleopole is located at S 27.4, W 57.0, with alpha-95 = 6.1° and k = 13.0 using 45 specimens from 31 oriented hand samples. These results agree fairly well with the mean reversed Carboniferous paleopole and Noltimier's coal pole, but are sufficiently different to raise the possibility of doing magnetostratigraphic correlations.

  6. XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments

    PubMed Central

    2012-01-01

    Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate. In this work we have analysed samples from two modern limestone monuments in Rome, the Botticino surfaces of the ‘Vittoriano’ (by G.Sacconi, 1885-1911- Piazza Venezia) and the travertine basement of the ‘Statua dello Studente’ (by A.Cataldi, 1920- University city, La Sapienza), and focussed our investigation on the chemical composition of the copper-stained zones using XPS (X-ray Photoelectron Spectroscopy) as a surface-specific technique. Based on observations reporting on the structure and bonding at the calcite surfaces we have identified copper complexes and mixed calcium/copper carbonates associated with the stains, as well as the chemical state of other elements therein included, and related the compositional changes with differences in chromatic characteristics and sampling locations. PMID:22594435

  7. XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments.

    PubMed

    Salvi, Anna Maria; Langerame, Fausto; Macchia, Andrea; Sammartino, Maria Pia; Tabasso, Marisa Laurenzi

    2012-01-01

    Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate.In this work we have analysed samples from two modern limestone monuments in Rome, the Botticino surfaces of the 'Vittoriano' (by G.Sacconi, 1885-1911- Piazza Venezia) and the travertine basement of the 'Statua dello Studente' (by A.Cataldi, 1920- University city, La Sapienza), and focussed our investigation on the chemical composition of the copper-stained zones using XPS (X-ray Photoelectron Spectroscopy) as a surface-specific technique.Based on observations reporting on the structure and bonding at the calcite surfaces we have identified copper complexes and mixed calcium/copper carbonates associated with the stains, as well as the chemical state of other elements therein included, and related the compositional changes with differences in chromatic characteristics and sampling locations. PMID:22594435

  8. Use Of limestone resources in flue-gas desulfurization power plants in the Ohio River Valley

    USGS Publications Warehouse

    Foose, M.P.; Barsotti, A.F.

    1999-01-01

    In 1994, more than 41 of the approximately 160 coal-fired, electrical- power plants within the six-state Ohio River Valley region used flue-gas desulfurization (FGD) units to desulfurize their emissions, an approximately 100% increase over the number of plants using FGD units in 1989. This increase represents a trend that may continue with greater efforts to meet Federal Clean Air Act standards. Abundant limestone resources exist in the Ohio River Valley and are accessed by approximately 975 quarries. However, only 35 of these are believed to have supplied limestone for FGD electrical generating facilities. The locations of these limestone suppliers do not show a simple spatial correlation with FGD facilities, and the closest quarries are not being used in most cases. Thus, reduction in transportation costs may be possible in some cases. Most waste generated by FGD electrical-generating plants is not recycled. However, many FGD sites are relatively close to gypsum wallboard producers that may be able to process some of their waste.

  9. [Sodium-enhanced limestone wet FGD in rotating-stream tray scrubber].

    PubMed

    Sun, Wenshou; Wu, Zhongbiao; Li, Yue; Tan, Tianen

    2002-09-01

    Adding sodium sulfate to limestone slurry can increase SO2 removal efficiency. In this paper, sodium-enhanced limestone flue gas desulfurization(FGD) tests were conducted in rotating-stream tray scrubber. Changes of SO2 removal efficiency and pH value with time were experimentally studied and, at different pH range, the dissolution rates of limestone etc. were analyzed. The effects of plate number on SO2 removal efficiency and pressure drop were investigated at temperature approximated to industrial operating value. The average plate efficiencies were calculated. According to the experimental results, increasing plate number could increase SO2 removal efficiency, but the average plate efficiency decreased. Under the experimental conditions, when the plate number was increased from 1 to 4, the removal efficiency was increased from 25.5% to 48.6% at the liquid-to-gas ratio of 4 L/m3, but the average plate efficiency was decreased from 25.5% to 15.3%. The equation of the relation between the average plate efficiency and plate number was obtained.

  10. Limestone surfaces in built-up environment as indicators of atmospheric pollution.

    PubMed

    Vella, A J; Camilleri, A; Tabone Adami, J P

    1996-12-01

    The concentration of sulphate on limestone surfaces of the external walls of churches in Malta is shown to be related to their position and distance from a power station, the main local point source of sulphur dioxide pollution. Limestone powder collected from these surfaces was examined for the presence of particles which, under low-power optical microscopy, appear as shiny black amorphous bodies which were interpreted as soot particles; the abundance of these bodies was expressed as a 'black particle count' (BPC). The degree of sulphation and BPC were shown to be correlated with each other and both appeared to be strongly dependent on the prevailing wind. The BPC contour map indicated an important contribution to the parameter from vehicular traffic. It is suggested that the degree of sulphation and BPC of limestone surfaces from the built environment should function as environmental indicators of the relative air quality with respect to SO2 and soot pollution. This data is possibly more accurately representative of the relative long-term air-quality status of different areas of habitation than that deduced from single or episodic measurements of atmospheric pollutant levels.

  11. The influence of temperature on limestone sulfation and attrition under fluidized bed combustion conditions

    SciTech Connect

    Montagnaro, Fabio; Salatino, Piero; Scala, Fabrizio

    2010-04-15

    The influence of temperature on attrition of two limestones during desulfurization in a fluidized bed reactor was investigated. Differences in the microstructure of the two limestones were reflected by a different thickness of the sulfate shell formed upon sulfation and by a different value of the ultimate calcium conversion degree. Particle attrition and fragmentation were fairly small under moderately bubbling fluidization conditions for both limestones. An increase of temperature from 850 C to 900 C led to an increase of the attrition rate, most likely because of a particle weakening effect caused by a faster CO{sub 2} evolution during calcination. This weakening effect, however, was not sufficiently strong to enhance particle fragmentation in the bed. The progress of sulfation, associated to the build-up of a hard sulfate shell around the particles, led in any case to a decrease of the extent of attrition. Sulfation at 900 C was less effective than at 850 C, and this was shown to be related to the porosimetric features of the different samples. (author)

  12. The sedimentological and diagenetic evolution of the Ratburi Limestone, Peninsular Thailand

    NASA Astrophysics Data System (ADS)

    Baird, Angus; Bosence, Dan

    The late Middle to early Late Permian Ratburi Limestone in Peninsular Thailand is a warm-water carbonate deposit formed in an extensive platform setting, suggesting that the Shan Thai craton occupied a subtropical-tropical position at this time. The distribution of facies, from peritidal, fenestral and algal laminated muds, to subtidal skeletal and ooid grainstones, bryozoa boundstones and carbonate slope deposits, is controlled by the platform topography, which is thought to have been controlled by extensional tectonics. Early diagenesis of the platform began with seawater-influenced dolomitisation, followed by uplift, producing karstification, in response to the Late Permian Indosinian orogeny. East dipping subduction of the Indian Ocean Plate resulted in granite magmatism in the peninsula during the Cretaceous. The effect on the Ratburi Limestone included neomorphism, dissolution, calcite cementation and dolomitisation. The petroleum potential of Ratburi Limestone comes from the extensive and long karstic history (Late Permian and Tertiary-present day) and the source potential of the widespread platform carbonate mudstone ( TOC <4.5%) .

  13. Stable isotope stratigraphy and larger benthic foraminiferal extinctions in the Melinau Limestone, Sarawak

    NASA Astrophysics Data System (ADS)

    Cotton, Laura J.; Pearson, Paul N.; Renema, Willem

    2014-01-01

    Important long-ranging groups of larger benthic foraminifera (LBF) are known to have become extinct during a period of global cooling and climate disruption at the Eocene-Oligocene transition (EOT) but the precise timing and mechanisms are uncertain. Recent study showed unexpectedly that the LBF extinction in Tanzania occurs very close to the Eocene/Oligocene boundary, as recognised by the extinction of the planktonic foraminiferal Family Hantkeninidae, rather than at the later period of maximum global ice growth and sea-level fall, as previously thought. Here we investigate the same phase of extinction in the Melinau Limestone of Sarawak, on the island of Borneo, Malaysia one of the most complete carbonate successions spanning the Eocene to Lower Miocene. Assemblages of LBF from the Melinau Limestone were studied extensively by Geoffrey Adams during the 1960s-80s, confirming a major extinction during the EOT, but the section lacked independent means of correlation. By analysing rock samples originally studied by Adams and now in the Natural History Museum, London, we provide new bulk stable isotope (δ13C and δ18O) records. This enables us to identify, albeit tentatively, the level of maximum stable isotope excursion and show that the LBF extinction event in the Melinau Limestone occurs below this isotope excursion, supporting the results from Tanzania and indicating that the extinction of LBF close to the Eocene/Oligocene boundary may be a global phenomenon.

  14. Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

    PubMed

    Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

    2016-01-01

    Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine.

  15. Multiple origins for zoned cathodoluminescent and noncathodoluminescent calcite cements in Pennsylvanian limestones

    SciTech Connect

    Goldstein, R.H.; Anderson, J.E.; Phares, R.A. )

    1991-03-01

    Noncathodoluminescent calcite containing brightly to moderately luminescent zones is a common early cement in limestones. Three such cements in Upper Pennsylvanian limestones from different areas were studied. All three units are overlain up-section by Permian evaporites and consist of carbonate-siliciclastic 'cyclothems' in which individual cycles were subject to subaerial exposure. With such similar settings, one might predict that petrographically similar calcite cements would have similar origins. In the Holder Formation (New Mexico), the zoned calcite predates compaction, and cross-cutting relationships with cycle-capping paleosols show that zoned cements precipitated during 15 events of subaerial exposure. Therefore, cements precipitated from freshwater during early and repeated subaerial exposure. For the Lansing-Kansas City groups in northwestern Kansas, the zoned calcite cements commonly are among the first precipitated but may postdate some compaction. All-liquid fluid inclusions indicated precipitation below about 50C, from brines of approximately 23 weight %. NaCl equivalent. The brines may have refluxed downward during deposition of Permian evaporites. A limestone of the Lansing-Kansas City groups of west-central Kansas contains early zoned calcite cement that predates compaction. The cement contains all-liquid fluid inclusions indicating precipitation below about 50C. The presence of nonluminescent calcite containing bright subzones is not indicative of a single diagenetic environment. Petrographically similar cements from similar settings may originate in markedly different diagenetic environments.

  16. A study of the dry forest communities in the Dominican Republic.

    PubMed

    García-Fuentes, Antonio; Torres-Cordero, Juan A; Ruiz-Valenzuela, Luis; Lendínez-Barriga, María Lucía; Quesada-Rincón, Juan; Valle-Tendero, Francisco; Veloz, Alberto; León, Yolanda M; Salazar-Mendías, Carlos

    2015-03-01

    This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.

  17. Studies on the reaction of calcined limestone with sulfur dioxide: Technical progress report for the period October-December 1986

    SciTech Connect

    Sotirchos, S.V.

    1987-01-01

    The primary objective of this project, which constitutes a balanced program of theoretical and experimental work, is the development of a systematic procedure for the prediction of the sorptive capacity of a given limestone or dolomite, for SO/sub 2/ removal, starting from basic physical principles and experimental information. Our research will chiefly focus on the experimental and theoretical investigation of the effects of the initial pore structure of limestone or dolomite and of its evolution with the progress of the reaction on the transient behavior of calcined limestone or dolomite particles reacting in an environment of SO/sub 2/ and O/sub 2/. Particular emphasis will be placed on the investigation of the intraparticle mass transport process since significant intraparticle concentration gradients may severely reduce the sorptive capacity of calcined limestones for SO/sub 2/ removal.

  18. Studies on the reaction of calcined limestone with sulfur dioxide: Technical progress report for the period July-September 1986

    SciTech Connect

    Sotirchos, S.V.

    1986-10-01

    The primary objective of this project, which constitutes a balanced program of theoretical and experimental work, is the development of a systematic procedure for the prediction of the sorptive capacity of a given limestone or dolomite, for SO/sub 2/ removal, starting from basic physical principles and experimental information. Our research will chiefly focus on the experimental and theoretical investigation of the effects of the initial pore structure of limestone or dolomite and of its evolution with the progress of the reaction on the transient behavior of calcined limestone or dolomite particles reacting in an environment of SO/sub 2/ and O/sub 2/. Particular emphasis will be placed on the investigation of the intraparticle mass transport process since significant intraparticle concentration gradients may severely reduce the sorptive capacity of calcined limestones for SO/sub 2/ removal.

  19. Evaluation of a surface application of limestone for controlling acid mine discharges from abandoned strip mines, Sewellsville, Ohio. Final report

    SciTech Connect

    Geidel, G.; Caruccio, F.T.

    1984-01-01

    A 150-acre drainage basin in an unreclaimed coal strip mine in east-central Ohio was studied and extensively monitored to determine the effect of a surface application of limestone on the ground water quality. Prior to the limestone treatment the ground and surface water of the basin was acidic due to pyrite oxidation in the spoil. The results of this field study and simultaneous laboratory experiments showed that the maximum amount of alkalinity that can be generated by a surface application of limestone is not sufficient to reduce the ground water acidity generated by pyrite oxidation. Additionally, the amount of limestone applied was not sufficient to significantly decrease the rate of pyrite oxidation nor provide neutralization and thereby produce neutral or alkaline discharges from the abandoned coal strip mine sites.

  20. A Stranger in the Midst: Searching for Relict Grains from Rare Meteorite Types in Mid-Ordovician Limestone Strata

    NASA Astrophysics Data System (ADS)

    Martin, E.; Schmitz, B.

    2016-08-01

    A layer of Mid-Ordovician limestone harbors exceptional amounts of L-chondritic chromite grains. The layer also contains grains from potentially rarer types of meteorites, following the discovery of the fossil meteorite Österplana 065.