Experimental measurements and evaluation of the expanded water repellent perlite used for the cargo containment system of LNG carrier

NASA Astrophysics Data System (ADS)

Li, Manfeng; Ju, Yonglin

2017-10-01

To minimize the water absorption and to improve the thermal insulated properties of the insulation materials used for the cargo containment systems (CCSs) of LNG carrier, a kind of expanded water-repellent perlite has been developed by coating hydrophobic membrane onto the outer surface of the expanded perlite to change its physical and chemical characteristics. Considering the CCSs operated in a wide temperature range from environmental temperature to cryogenic temperature, the thermal analysis has been conducted to quantitatively determine the thermal insulted properties of the insulation materials. Furthermore, a double-sided guarded hot plate apparatus (GHP) is specifically designed and fabricated for the measurement of the thermal conductivities of the insulation specimens operated down to liquid nitrogen temperature. The breakage ratio associated with the water absorption and the thermal conductivity of the expanded water-repellent perlite is firstly proposed, and then a series of experiments are carried out to determine the thermal conductivity of the expanded water-repellent perlite ranging from room temperature to cryogenic temperature based on the different breakage ratios.

Peculiarities of binding composition production in vortex jet mill

NASA Astrophysics Data System (ADS)

Zagorodnyuk, L. Kh; Lesovik, V. S.; Sumskoy, D. A.; Elistratkin, M. Yu; Makhortov, D. S.

2018-03-01

The article investigates the disintegration of perlite production waste in a vortex jet mill; the regularities of milling were established. Binding compositions were obtained at different ratios of cement vs. perlite sand production waste in the vortex jet mill in various milling regimes. The peculiarities of milling processes were studied, and technological and physicomechanical properties of the binding compositions were determined as well. The microstructure of the cement stones made of activated Portland cement and binding compositions in the vortex jet mill was elucidated by electron microscopy. The open pores of the cement-binding compositions prepared using perlite fillers were found to be filled by newgrowths at different stages of collective growth. The microstructure of the binding compositions is dense due to rationally proportioned composition, effective mineral filler— perlite waste — that creates additional substrates for internal composite microstructure formation, mechanochemical activation of raw mixture, which allows obtaining composites with required properties.

Polymer-Cement Composites Containing Waste Perlite Powder

PubMed Central

Łukowski, Paweł

2016-01-01

Polymer-cement composites (PCCs) are materials in which the polymer and mineral binder create an interpenetrating network and co-operate, significantly improving the performance of the material. On the other hand, the need for the utilization of waste materials is a demand of sustainable construction. Various mineral powders, such as fly ash or blast-furnace slag, are successfully used for the production of cement and concrete. This paper deals with the use of perlite powder, which is a burdensome waste from the process of thermal expansion of the raw perlite, as a component of PCCs. The results of the testing of the mechanical properties of the composite and some microscopic observations are presented, indicating that there is a possibility to rationally and efficiently utilize waste perlite powder as a component of the PCC. This would lead to creating a new type of building material that successfully meets the requirements of sustainable construction. PMID:28773961

Low-δD hydration rinds in Yellowstone perlites record rapid syneruptive hydration during glacial and interglacial conditions

USGS Publications Warehouse

Bindeman, Ilya N.; Lowenstern, Jacob B.

2016-01-01

Hydration of silicic volcanic glass forms perlite, a dusky, porous form of altered glass characterized by abundant “onion-skin” fractures. The timing and temperature of perlite formation are enigmatic and could plausibly occur during eruption, during post-eruptive cooling, or much later at ambient temperatures. To learn more about the origin of natural perlite, and to fingerprint the hydration waters, we investigated perlitic glass from several synglacial and interglacial rhyolitic lavas and tuffs from the Yellowstone volcanic system. Perlitic cores are surrounded by a series of conchoidal cracks that separate 30- to 100-µm-thick slivers, likely formed in response to hydration-induced stress. H2O and D/H profiles confirm that most D/H exchange happens together with rapid H2O addition but some smoother D/H variations may suggest separate minor exchange by deuterium atom interdiffusion following hydration. The hydrated rinds (2–3 wt% H2O) transition rapidly (within 30 µm, or by 1 wt% H2O per 10 µm) to unhydrated glass cores. This is consistent with quenched “hydration fronts” where H2O diffusion coefficients are strongly dependent on H2O concentrations. The chemical, δ18O, and δD systematics of bulk glass records last equilibrium between ~110 and 60 °C without chemical exchange but with some δ18O exchange. Similarly, the δ18O of water extracted from glass by rapid heating suggests that water was added to the glass during cooling at <200 °C. Our observations support fast hydration at temperatures as low as 60 °C; prolonged exposure to high temperature of 175°–225° during water addition is less likely as the glass would lose alkalies and should alter to clays within days. A compilation of low-temperature hydration diffusion coefficients suggests ~2 orders of magnitude higher rates of diffusion at 60–110 °C temperatures, compared with values expected from extrapolation of high-temperature (>400 °C) experimental data. The thick hydration rinds in perlites, measuring hundreds of microns, preserve the original D/H values of hydrating water as a recorder of paleoclimate conditions. Measured δD values in perlitic lavas are −150 to −191 or 20–40 ‰ lower than glass hydrated by modern Yellowstone waters. This suggests that Yellowstone perlites record the low-δD signature of glacial ice. Cooling calculations, combined with the observed high water diffusion coefficients noted for 60–150 °C, suggest that if sufficient hot water or steam is available, any rhyolite flow greater than ~5 m thick can develop the observed ~250-µm hydration rinds within the expected timescale of cooling (weeks–years). As the process of hydration involves shattering of 30- to 100-µm-thick slivers to expose unhydrated rhyolite glass, the time required for hydration may be even shorter. Rapid hydration and formation of relatively thick-walled glass shards allow perlites to provide a snapshot view of the meteoric water (and thus climate) at the time of initial alteration. Perlites retain their initial hydration D/H signal better than thin-walled ash, which in contrast hydrates over many thousands of years with time-averaged precipitation.

Low-δD hydration rinds in Yellowstone perlites record rapid syneruptive hydration during glacial and interglacial conditions

NASA Astrophysics Data System (ADS)

Bindeman, Ilya N.; Lowenstern, Jacob B.

2016-11-01

Hydration of silicic volcanic glass forms perlite, a dusky, porous form of altered glass characterized by abundant "onion-skin" fractures. The timing and temperature of perlite formation are enigmatic and could plausibly occur during eruption, during post-eruptive cooling, or much later at ambient temperatures. To learn more about the origin of natural perlite, and to fingerprint the hydration waters, we investigated perlitic glass from several synglacial and interglacial rhyolitic lavas and tuffs from the Yellowstone volcanic system. Perlitic cores are surrounded by a series of conchoidal cracks that separate 30- to 100-µm-thick slivers, likely formed in response to hydration-induced stress. H2O and D/H profiles confirm that most D/H exchange happens together with rapid H2O addition but some smoother D/H variations may suggest separate minor exchange by deuterium atom interdiffusion following hydration. The hydrated rinds (2-3 wt% H2O) transition rapidly (within 30 µm, or by 1 wt% H2O per 10 µm) to unhydrated glass cores. This is consistent with quenched "hydration fronts" where H2O diffusion coefficients are strongly dependent on H2O concentrations. The chemical, δ18O, and δD systematics of bulk glass records last equilibrium between 110 and 60 °C without chemical exchange but with some δ18O exchange. Similarly, the δ18O of water extracted from glass by rapid heating suggests that water was added to the glass during cooling at <200 °C. Our observations support fast hydration at temperatures as low as 60 °C; prolonged exposure to high temperature of 175°-225° during water addition is less likely as the glass would lose alkalies and should alter to clays within days. A compilation of low-temperature hydration diffusion coefficients suggests 2 orders of magnitude higher rates of diffusion at 60-110 °C temperatures, compared with values expected from extrapolation of high-temperature (>400 °C) experimental data. The thick hydration rinds in perlites, measuring hundreds of microns, preserve the original D/H values of hydrating water as a recorder of paleoclimate conditions. Measured δD values in perlitic lavas are -150 to -191 or 20-40 ‰ lower than glass hydrated by modern Yellowstone waters. This suggests that Yellowstone perlites record the low-δD signature of glacial ice. Cooling calculations, combined with the observed high water diffusion coefficients noted for 60-150 °C, suggest that if sufficient hot water or steam is available, any rhyolite flow greater than 5 m thick can develop the observed 250-µm hydration rinds within the expected timescale of cooling (weeks-years). As the process of hydration involves shattering of 30- to 100-µm-thick slivers to expose unhydrated rhyolite glass, the time required for hydration may be even shorter. Rapid hydration and formation of relatively thick-walled glass shards allow perlites to provide a snapshot view of the meteoric water (and thus climate) at the time of initial alteration. Perlites retain their initial hydration D/H signal better than thin-walled ash, which in contrast hydrates over many thousands of years with time-averaged precipitation.

Effects of litter addition on ectomycorrhizal associates of a lodgepole pine (Pinus contorta) stand in Yellowstone National Park

NASA Technical Reports Server (NTRS)

Cullings, Kenneth W.; New, Michael H.; Makhija, Shilpa; Parker, V. Thomas

2003-01-01

Increasing soil nutrients through litter manipulation, pollution, or fertilization can adversely affect ectomycorrhizal (EM) communities by inhibiting fungal growth. In this study, we used molecular genetic methods to determine the effects of litter addition on the EM community of a Pinus contorta stand in Yellowstone National Park that regenerated after a stand-replacing fire. Two controls were used; in unmodified control plots nothing was added to the soil, and in perlite plots perlite, a chemically neutral substance, was added to maintain soil moisture and temperature at levels similar to those under litter. We found that (i) species richness did not change significantly following perlite addition (2.6 +/- 0.3 species/core in control plots, compared with 2.3 +/- 0.3 species/core in perlite plots) but decreased significantly (P < 0.05) following litter addition (1.8 +/- 0.3 species/core); (ii) EM infection was not affected by the addition of perlite but increased significantly (P < 0.001) in response to litter addition, and the increase occurred only in the upper soil layer, directly adjacent to the added litter; and (iii) Suillus granulatus, Wilcoxina mikolae, and agaricoid DD were the dominant organisms in controls, but the levels of W. mikolae and agaricoid DD decreased significantly in response to both perlite and litter addition. The relative levels of S. granulatus and a fourth fungus, Cortinariaceae species 2, increased significantly (P < 0.01 and P < 0.05, respectively) following litter addition. Thus, litter addition resulted in some negative effects that may be attributable to moisture-temperature relationships rather than to the increased nutrients associated with litter. Some species respond positively to litter addition, indicating that there are differences in their physiologies. Hence, changes in the EM community induced by litter accumulation also may affect ecosystem function.

The effect of nitrate on ethylene biofiltration.

PubMed

Lee, Sang-Hun; Li, Congna; Heber, Albert J

2012-11-30

This study investigated the effects of filter media types and nitrate (NO(3)(-)) concentrations in nutrient solutions on C(2)H(4) biofiltration. A new nutrient solution with zero NO(3)(-) concentration was supplied to two perlite-bed biotrickling filters, two perlite-bed biofilters, and two GAC (Granular Activated Carbon)-bed biofilters, while the other with 2 g L(-1) of NO(3)(-) was used for the other two GAC biofilters. All reactors underwent a total test duration of over 175 days with an EBRT (Empty Bed Residence Time) of 30 s, inlet gas flow rate of 7 L min(-1), and inlet C(2)H(4) concentrations of 20-30 mg m(-3). NO(3)(-) concentration and media type significantly affected the C(2)H(4) removal efficiencies in all types of biofiltration. The perlite media with no NO(3)(-) achieved C(2)H(4) removal efficiencies 10-50% higher than the others. A NO(3)(-) concentration as high as 2 g L(-1) in the original nutrient solution may act as an inhibitor that suppresses the growth or activity of C(2)H(4) degraders. In addition, the perlite media resulted in higher C(2)H(4) removal efficiencies than GAC media, because the hydrophilic surface of the perlite leads to a higher moisture content and thus to favorable microbial growth. Copyright © 2012 Elsevier B.V. All rights reserved.

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: STORMWATER MANAGEMENT STORMFILTER® TREATMENT SYSTEM USING PERLITE MEDIA

EPA Science Inventory

Verification testing of the Stormwater Management, Inc. StormFilter® Using Perlite Filter Media was conducted on a 0.7 acre drainage basin near downtown Griffin, Georgia. The system consists of an inlet bay, flow spreader, cartridge bay, overflow baffle, and outlet bay, housed in...

Feasibility study for measurement of insulation compaction in the cryogenic rocket fuel storage tanks at Kennedy Space Center by fast/thermal neutron techniques

NASA Astrophysics Data System (ADS)

Livingston, R. A.; Schweitzer, J. S.; Parsons, A. M.; Arens, E. E.

2014-02-01

The liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC) use expanded perlite as thermal insulation. Some of the perlite may have compacted over time, compromising the thermal performance and also the structural integrity of the tanks. Neutrons can readily penetrate through the 1.75 cm outer steel shell and through the entire 120 cm thick perlite zone. Neutrons interactions with materials produce characteristic gamma rays which are then detected. In compacted perlite the count rates in the individual peaks in the gamma ray spectrum will increase. Portable neutron generators can produce neutron simultaneous fluxes in two energy ranges: fast (14 MeV) and thermal (25 meV). Fast neutrons produce gamma rays by inelastic scattering which is sensitive to Si, Al, Fe and O. Thermal neutrons produce gamma rays by radiative capture in prompt gamma neutron activation (PGNA), which is sensitive to Si, Al, Na, K and H among others. The results of computer simulations using the software MCNP and measurements on a test article suggest that the most promising approach would be to operate the system in time-of-flight mode by pulsing the neutron generator and observing the subsequent die away curve in the PGNA signal.

Influence of aggregate type and chemical admixtures on frost resistance of lightweight mortars

NASA Astrophysics Data System (ADS)

Klimek, Beata; Widomski, Marcin K.; Barnat-Hunek, Danuta

2017-07-01

The aim of studies presented in this paper covered analyses of type of lightweight aggregate as well as aeration and hydrophobic admixtures influence on absorbability and frost resistance of heat-insulating mortars applied in the energy-efficient construction. In the presented research, expanded perlite (EP) and expanded clay aggregate (ceramsite) were used as lightweight aggregates. The measurements of the basic mechanical and physical characteristics of tested mortars were performed, including, inter alia, compressive and flexural tensile strength, density, effective (open) and total porosity, absorbability, thermal conductivity as well as frost resistance after 25 cycles of freezing and thawing. Substitution of some part of sand fraction by the lightweight aggregates, expanded clay aggregate or perlite, resulted in changes in physical properties of the tested mortars. The observed decrease in density (specific weight), coefficient of heat transport and strength parameters were simultaneously accompanied by the increase in absorbability. Researches concerning frost resistance of mortars containing ceramsite and perlite showed the improved frost resistance of mortar utilizing perlite. Most of the tested mortars shoved satisfactory frost resistance, only samples of mortar containing ceramsite and aeration admixture were destroyed. The significant influence of aerating admixture on frost resistance of mortars was determined. Hydrophobic siloxanes addition failed to adequately protect the mortars against frost erosion, regardless the type of applied aggregate.

Thermal Performance Comparison of Glass Microsphere and Perlite Insulation Systems for Liquid Hydrogen Storage Tanks

NASA Astrophysics Data System (ADS)

Sass, J. P.; Fesmire, J. E.; Nagy, Z. F.; Sojourner, S. J.; Morris, D. L.; Augustynowicz, S. D.

2008-03-01

A technology demonstration test project was conducted by the Cryogenics Test Laboratory at the Kennedy Space Center (KSC) to provide comparative thermal performance data for glass microspheres, referred to as bubbles, and perlite insulation for liquid hydrogen tank applications. Two identical 1/15th scale versions of the 3,200,000 liter spherical liquid hydrogen tanks at Launch Complex 39 at KSC were custom designed and built to serve as test articles for this test project. Evaporative (boil-off) calorimeter test protocols, including liquid nitrogen and liquid hydrogen, were established to provide tank test conditions characteristic of the large storage tanks that support the Space Shuttle launch operations. This paper provides comparative thermal performance test results for bubbles and perlite for a wide range of conditions. Thermal performance as a function of cryogenic commodity (nitrogen and hydrogen), vacuum pressure, insulation fill level, tank liquid level, and thermal cycles will be presented.

Thermal diffusivity and adiabatic limit temperature characterization of consolidate granular expanded perlite using the flash method

NASA Astrophysics Data System (ADS)

Raefat, Saad; Garoum, Mohammed; Laaroussi, Najma; Thiam, Macodou; Amarray, Khaoula

2017-07-01

In this work experimental investigation of apparent thermal diffusivity and adiabatic limit temperature of expanded granular perlite mixes has been made using the flash technic. Perlite granulates were sieved to produce essentially three characteristic grain sizes. The consolidated samples were manufactured by mixing controlled proportions of the plaster and water. The effect of the particle size on the diffusivity was examined. The inverse estimation of the diffusivity and the adiabatic limit temperature at the rear face as well as the heat losses coefficients were performed using several numerical global minimization procedures. The function to be minimized is the quadratic distance between the experimental temperature rise at the rear face and the analytical model derived from the one dimension heat conduction. It is shown that, for all granulometry tested, the estimated parameters lead to a good agreement between the mathematical model and experimental data.

Perlite

USGS Publications Warehouse

Bolen, W.

2012-01-01

Domestic production, consumption, exports and prices of perlite in the United States were all estimated to have decreased in 2011 compared with 2010, but not significantly. The weak economic conditions that prevailed in the United States for most of the 2011 probably accounted for these decreases. The only statistic that increased was imports, which were estimated to have risen by about 6 percent but were still about 24 percent lower than the record of 245 kt (271,000 st) set in 2003 and again in 2006.

Utilization of Natural Zeolite and Perlite as Landfill Liners for in Situ Leachate Treatment in Landfills

PubMed Central

Ozel, Ummukulsum; Akdemir, Andaç; Ergun, Osman Nuri

2012-01-01

The potential long term environmental impacts of a landfill on groundwater quality depend on its liner material properties. In case synthetic liner materials are damaged during the construction or operation, many of the original chemical and biological constituents are removed by filtration and the adsorptive action of natural liner materials such as natural zeolite, perlite and bentonite minerals. Before leachate treatment, reduction of these constituents is important not only to leachate percolation, but also treatment cost and efficiency. In this study, the pollutant removal efficiency from the leachate was investigated for natural natural zeolite, expanded perlite and bentonite. Experimental studies was performed in boxes made of glass and with 1:10 sloping. Leachate quantity was determined and pH, electrical conductivity (EC), nitrate (NO3-N), ammonium-nitrogen (NH4-N), phosphate (PO4), chemical oxygen demand (COD) and organic matter in leachate samples were measured and the measurement was compared with control process (System 4). The results showed that natural zeolite was effective in removing NO3, NH4, PO4, COD and organic matter with removal efficiencies of 91.20, 95.6, 95.5, 83.4 and 87.8%, respectively. Expanded perlite has high efficiency removing of NO3, PO4 and COD 83.2, 91.0 and 62.5%, respectively, but it was unsuccessful in reducing NH4 (1.5%). PMID:22754458

Utilization of natural zeolite and perlite as landfill liners for in situ leachate treatment in landfills.

PubMed

Ozel, Ummukulsum; Akdemir, Andaç; Ergun, Osman Nuri

2012-05-01

The potential long term environmental impacts of a landfill on groundwater quality depend on its liner material properties. In case synthetic liner materials are damaged during the construction or operation, many of the original chemical and biological constituents are removed by filtration and the adsorptive action of natural liner materials such as natural zeolite, perlite and bentonite minerals. Before leachate treatment, reduction of these constituents is important not only to leachate percolation, but also treatment cost and efficiency. In this study, the pollutant removal efficiency from the leachate was investigated for natural natural zeolite, expanded perlite and bentonite. Experimental studies was performed in boxes made of glass and with 1:10 sloping. Leachate quantity was determined and pH, electrical conductivity (EC), nitrate (NO(3)-N), ammonium-nitrogen (NH(4)-N), phosphate (PO(4)), chemical oxygen demand (COD) and organic matter in leachate samples were measured and the measurement was compared with control process (System 4). The results showed that natural zeolite was effective in removing NO(3), NH(4), PO(4), COD and organic matter with removal efficiencies of 91.20, 95.6, 95.5, 83.4 and 87.8%, respectively. Expanded perlite has high efficiency removing of NO(3), PO(4) and COD 83.2, 91.0 and 62.5%, respectively, but it was unsuccessful in reducing NH(4) (1.5%).

Vibration and Thermal Cycling Effects on Bulk-fill Insulation Materials for Cryogenic Tanks

NASA Astrophysics Data System (ADS)

Fesmire, J. E.; Augustynowicz, S. D.; Nagy, Z. F.; Sojourner, S. J.; Morris, D. L.

2006-04-01

Large-scale (1,000,000 liters or more) cryogenic storage tanks are typically perlite-insulated double-walled vessels. Associated problems with perlite, such as mechanical compaction and settling, could be greatly reduced by using newer bulk-fill materials such as glass bubbles or aerogel beads. Using the newer materials should translate to lower life cycle costs and improved system reliability. NASA Kennedy Space Center is leveraging its experience in the areas of materials development, insulation testing, and cryogenic systems design to develop an insulation retrofit option that will meet both industry and NASA requirements. A custom 10-liter dewar test apparatus, developed by the KSC Cryogenics Test Laboratory, was used to determine the vibration and thermal cycling effects on different bulk-fill insulation materials for cryogenic tanks. The testing included liquid-nitrogen boiloff testing and thermal cycling (with vibration) of a number of test dewars. Test results show that glass bubbles have better thermal performance and less mechanical compaction compared to perlite powder. The higher cost of the bulk material should be offset by reduced commodity loss from boiloff and improvements in material handling, evacuation, and vacuum retention. The long-term problem with settling and compaction of perlite should also be eliminated. Aerogel beads are superior for the no-vacuum condition and can now be considered in some applications. Further studies on large-scale systems are presently being pursued.

Feasibility study for measurement of insulation compaction in the cryogenic rocket fuel storage tanks at Kennedy Space Center by fast/thermal neutron techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livingston, R. A.; Schweitzer, J. S.; Parsons, A. M.

2014-02-18

The liquid hydrogen and oxygen cryogenic storage tanks at John F. Kennedy Space Center (KSC) use expanded perlite as thermal insulation. Some of the perlite may have compacted over time, compromising the thermal performance and also the structural integrity of the tanks. Neutrons can readily penetrate through the 1.75 cm outer steel shell and through the entire 120 cm thick perlite zone. Neutrons interactions with materials produce characteristic gamma rays which are then detected. In compacted perlite the count rates in the individual peaks in the gamma ray spectrum will increase. Portable neutron generators can produce neutron simultaneous fluxes inmore » two energy ranges: fast (14 MeV) and thermal (25 meV). Fast neutrons produce gamma rays by inelastic scattering which is sensitive to Si, Al, Fe and O. Thermal neutrons produce gamma rays by radiative capture in prompt gamma neutron activation (PGNA), which is sensitive to Si, Al, Na, K and H among others. The results of computer simulations using the software MCNP and measurements on a test article suggest that the most promising approach would be to operate the system in time-of-flight mode by pulsing the neutron generator and observing the subsequent die away curve in the PGNA signal.« less

Method and Apparatus of Measuring Velocity and Sound Attenuation Coefficient in Bulk Materials Based on the Analysis of the Structure of Sound-Insulation Materials on the Basis of Perlite

NASA Astrophysics Data System (ADS)

Kapranov, B. I.; Mashanov, A. P.

2017-04-01

This paper presents the results of research and describes the apparatus for measuring the acoustic characteristics of bulk materials. Ultrasound, it has passed through a layer of bulk material, is further passes through an air gap. The presence of air gap prevents from measuring tract mechanical contacts, but complicates the measurement technology Studies were conducted on the example of measuring the acoustic characteristics of the widely used perlite-based sound-proofing material.

Uranium mobility during interaction of rhyolitic obsidian, perlite and felsite with alkaline carbonate solution: T = 120° C, P = 210 kg/cm2

USGS Publications Warehouse

Zielinski, Robert A.

1979-01-01

Well-characterized samples of rhyolitic obsidian, perlite and felsite from a single lava flow are leached of U by alkaline oxidizing solutions under open-system conditions. Pressure, temperature, flow rate and solution composition are held constant in order to evaluate the relative importance of differences in surface area and crystallinity. Under the experimental conditions U removal from crushed glassy samples proceeds by a mechanism of glass dissolution in which U and silica are dissolved in approximately equal weight fractions. The rate of U removal from crushed glassy samples increases with decreasing average grain size (surface area). Initial rapid loss of a small component (≈ 2.5%) of the total U from crushed felsite. followed by much slower U loss, reflects variable rates of attack of numerous uranium sites. The fractions of U removed during the experiment ranged from 3.2% (felsite) to 27% (perlite). An empirical method for evaluating the relative rate of U loss from contemporaneous volcanic rocks is presented which incorporates leaching results and rock permeability data.

Glass Bubbles Insulation for Liquid Hydrogen Storage Tanks

NASA Technical Reports Server (NTRS)

Sass, J. P.; SaintCyr, W. W.; Barrett, T. M.; Baumgartner, R. G.; Lott, J. W.; Fesmire, J. E.

2009-01-01

A full-scale field application of glass bubbles insulation has been demonstrated in a 218,000 L liquid hydrogen storage tank. This work is the evolution of extensive materials testing, laboratory scale testing, and system studies leading to the use of glass bubbles insulation as a cost efficient and high performance alternative in cryogenic storage tanks of any size. The tank utilized is part of a rocket propulsion test complex at the NASA Stennis Space Center and is a 1960's vintage spherical double wall tank with an evacuated annulus. The original perlite that was removed from the annulus was in pristine condition and showed no signs of deterioration or compaction. Test results show a significant reduction in liquid hydrogen boiloff when compared to recent baseline data prior to removal of the perlite insulation. The data also validates the previous laboratory scale testing (1000 L) and full-scale numerical modeling (3,200,000 L) of boiloff in spherical cryogenic storage tanks. The performance of the tank will continue to be monitored during operation of the tank over the coming years. KEYWORDS: Glass bubble, perlite, insulation, liquid hydrogen, storage tank.

Long-term performance of passive materials for removal of ozone from indoor air.

PubMed

Cros, C J; Morrison, G C; Siegel, J A; Corsi, R L

2012-02-01

The health effects associated with exposure to ozone range from respiratory irritation to increased mortality. In this paper, we explore the use of three green building materials and an activated carbon (AC) mat that remove ozone from indoor air. We studied the effects of long-term exposure of these materials to real environments on ozone removal capability and pre- and post-ozonation emissions. A field study was completed over a 6-month period, and laboratory testing was intermittently conducted on material samples retrieved from the field. The results show sustained ozone removal for all materials except recycled carpet, with greatest ozone deposition velocity for AC mat (2.5-3.8 m/h) and perlite-based ceiling tile (2.2-3.2 m/h). Carbonyl emission rates were low for AC across all field sites. Painted gypsum wallboard and perlite-based ceiling tile had similar overall emission rates over the 6-month period, while carpet had large initial emission rates of undesirable by-products that decayed rapidly but remained high compared with other materials. This study confirms that AC mats and perlite-based ceiling tile are viable surfaces for inclusion in buildings to remove ozone without generating undesirable by-products. PRACTICAL IMPLICATIONS The use of passive removal materials for ozone control could decrease the need for, or even render unnecessary, active but energy consuming control solutions. In buildings where ozone should be controlled (high outdoor ozone concentrations, sensitive populations), materials specifically designed or selected for removing ozone could be implemented, as long as ozone removal is not associated with large emissions of harmful by-products. We find that activated carbon mats and perlite-based ceiling tiles can provide substantial, long-lasting, ozone control. © 2011 John Wiley & Sons A/S.

Annular Air Leaks in a liquid hydrogen storage tank

NASA Astrophysics Data System (ADS)

Krenn, AG; Youngquist, RC; Starr, SO

2017-12-01

Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

Demonstration of Microsphere Insulation in Cryogenic Vessels

NASA Astrophysics Data System (ADS)

Baumgartner, R. G.; Myers, E. A.; Fesmire, J. E.; Morris, D. L.; Sokalski, E. R.

2006-04-01

While microspheres have been recognized as a legitimate insulation material for decades, actual use in full-scale cryogenic storage tanks has not been demonstrated until now. The performance and life-cycle-cost advantages previously predicted have now been proven. Most bulk cryogenic storage tanks are insulated with either multilayer insulation (MLI) or perlite. Microsphere insulation, consisting of hollow glass bubbles, combines in a single material the desirable properties that other insulations only have individually. The material has high crush strength, low density, is noncombustible, and performs well in soft vacuum. These properties were proven during recent field testing of two 22,700-L (6,000-gallon) liquid nitrogen tanks, one insulated with microsphere insulation and the other with perlite. Normal evaporation rates (NER) for both tanks were monitored with precision test equipment and insulation levels within the tanks were observed through view ports as an indication of insulation compaction. Specific industrial applications were evaluated based on the test results and beneficial properties of microsphere insulation. Over-the-road trailers previously insulated with perlite will benefit not only from the reduced heat leak, but also the reduced mass of microsphere insulation. Economic assessments for microsphere-insulated cryogenic vessels including life-cycle cost are also presented.

Photocatalytic degradation of sulfamethoxazole in aqueous solution using a floating TiO2-expanded perlite photocatalyst.

PubMed

Długosz, Maciej; Żmudzki, Paweł; Kwiecień, Anna; Szczubiałka, Krzysztof; Krzek, Jan; Nowakowska, Maria

2015-11-15

Photocatalytic degradation of an antibiotic, sulfamethoxazole (SMX), in aqueous solution using a novel floating TiO2-expanded perlite photocatalyst (EP-TiO2-773) and radiation from the near UV spectral range was studied. The process is important considering that SMX is known to be a widespread and highly persistent pollutant of water resources. SMX degradation was described using a pseudo-first-order kinetic equation according to the Langmuir-Hinshelwood model. The products of the SMX photocatalytic degradation were identified. The effect of pH on the kinetics and mechanism of SMX photocatalytic degradation was explained. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance of innovative PU-foam and natural fiber-based composites for the biofiltration of a mixture of volatile organic compounds by a fungal biofilm.

PubMed

Gutiérrez-Acosta, O B; Arriaga, S; Escobar-Barrios, V A; Casas-Flores, S; Almendarez-Camarillo, A

2012-01-30

The performance of perlite and two innovative carriers that consist of polyurethane (PU) chemically modified with starch; and polypropylene reinforced with agave fibers was evaluated in the biofiltration of a mixture of VOCs composed of hexane, toluene and methyl-ethyl-ketone. At a total organic loading rate of 145 gCm(-3)h(-1) the elimination capacities (ECs) obtained were 145, 24 and 96 gCm(-3)h(-1) for the biofilters packed with the PU, the reinforced polypropylene, and perlite, respectively. Specific maximum biodegradation rates of the mixture, in the biofilters, were 416 mgCg(protein)(-1)  h(-1) for the PU and 63 mgCg(protein)(-1) h(-1) for perlite, which confirms the highest performance of the PU-composite. 18S rDNA analysis from the PU-biofilter revealed the presence of Fusarium solani in its sexual and asexual states, respectively. The modified PU carrier significantly reduced the start-up period of the biofilter and enhanced the EC of the VOCs. Thus, this study gives new alternatives in the field of packing materials synthesis, promoting the addition of easily biodegradable sources to enhance the performance of biofilters. Copyright © 2011 Elsevier B.V. All rights reserved.

Mineral resources of the Meadow Valley Range Wilderness Study Area, Lincoln and Clark counties, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pampeyan, E.H.; Blank, H.R. Jr.; Campbell, H.W.

1988-01-01

The authors report that no mines or active prospects are located within the study area. The only identified resource is perlite. The northern part of the study area has moderate resource potential for zeolites,marekanite (Apache tears), agate, and opaline rock associated with the perlite, and tin. The southern part of the study area has low resource potential for sediment-hosted gold, silver, zinc, copper, and lead. The study area has moderate potential for oil and gas resources. Identified resources of vanadium are present outside the study area and about 800,000 tons of subeconomic metalliferous resources are inferred in the outcrop area,more » however the potential for undiscovered vanadium resources within the immediately adjacent study area is unknown.« less

The behavior of biogenic silica-rich rocks and volcanic tuffs as pozzolanic additives in cement

NASA Astrophysics Data System (ADS)

Fragoulis, Dimitris; Stamatakis, Michael; Anastasatou, Marianthi

2015-04-01

Cements currently produced, include a variety of pozzolanic materials, aiming for lower clinker addition and utilization of vast deposits of certain raw materials and/or mining wastes and byproducts. The major naturally occurring pozzolanic materials include glassy tuffs, zeolitic tuffs, diatomites and volcanic lavas rich in glassy phase, such as perlites. Therefore, based on the available raw materials in different locations, the cement composition might vary according to the accessibility of efficient pozzolanic materials. In the present investigation, the behavior of pozzolanic cements produced with representative samples of the aforementioned materials was studied, following the characterization of the implemented pozzolanas with respect to their chemical and mineralogical characteristics. Laboratory cements were produced by co-grinding 75% clinker, 5% gypsum and 20% pozzolana, for the same period of time (45 min). Regarding pozzolanic materials, four different types of pozzolanas were utilized namely, diatomite, perlite, zeolite tuff and glassy tuff. More specifically, two diatomite samples originated from Australia and Greece, with high and low reactive silica content respectively, two perlite samples originated from Turkey and from Milos Island, Greece, with different reactive silica contents, a zeolite tuff sample originated from Turkey and a glassy tuff sample originated from Milos Island, Greece. The above pozzolana samples, which were ground in the laboratory ball mill for cement production performed differently during grinding and that was reflected upon the specific surface area (cm2/gr) values. The perlites and the glassy tuff were the hardest to grind, whereas, the zeolite tuff and the Australian diatomite were the easiest ones. However, the exceedingly high specific surface area of the Australian diatomite renders cement difficult to transport and tricky to use for concrete manufacturing, due to the high water demand of the cement mixture. Regarding late compressive strength, the worst performing cement was the one with the lowest reactive silica content with biogenic opal-A as the only reactive pozzolana constituent. Cements produced with perlites, raw materials consisting mainly of a glassy phase, were characterized by higher strength and a rather ordinary specific surface area. Cements produced with Turkish zeolite tuff and Milos glassy tuff exhibited higher late compressive strength than those mentioned above. The highest strength was achieved by the implementation of Australian diatomite for cement production. Its 28 day strength exceeded that of the control mixture consisting of 95% clinker and 5% gypsum. That could be attributed to both, high specific surface of cement and reactive SiO2 of diatomite. Therefore, a preliminary assessment regarding late strength of pozzolanic cements could be obtained by the consideration of two main parameters, namely: specific surface area of cement and reactive silica content of pozzolana.

Use of plant growth promoting bacterial strains to improve Cytisus striatus and Lupinus luteus development for potential application in phytoremediation.

PubMed

Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

2017-03-01

Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion. The use of PGP strains in phytoremediation may help plants to overcome contaminant and other soil stresses, increasing phytoremediation efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitrogen-enriched carbon sheets derived from egg white by using expanded perlite template and its high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Chen, Jiucun; Liu, Yinqin; Li, Wenjun; Xu, Liqun; Yang, Huan; Li, Chang Ming

2015-08-01

Nitrogen-enriched carbon sheets were synthesized using egg white as a unique carbon source and expanded perlite as a novel template. The as-prepared material was further used as an electrode material for supercapacitor applications, demonstrating excellent supercapacitance with a maximum gravimetric specific capacitance of 302 F g-1 at 0.5 A g-1 in a 3-electrode setup for a sample carbonized at 850 °C and activated for 6 h. Moreover, the carbon sheet-based capacitor with 2-symmetric electrodes showed an excellent cycle life (2% loss at 0.1 A g-1 after 10 000 cycles). The excellent performance may be attributed to the combination of the 3D carbon structure and the highly concentrated doped nitrogen component from the natural egg source for superior pseudocapacitance.

Compressive and flexural strength of expanded perlite aggregate mortar subjected to high temperatures

NASA Astrophysics Data System (ADS)

Zulkifeli, Muhamad Faqrul Hisham bin Mohd; Saman@Hj Mohamed, Hamidah binti Mohd

2017-08-01

Work on thermal resistant of outer structures of buildings is one of the solution to reduce death, damages and properties loss in fire cases. Structures protected with thermal resistant materials can delay or avoid failure and collapse during fire. Hence, establishment of skin cladding with advance materials to protect the structure of buildings is a necessary action. Expanded perlite is a good insulation material which can be used as aggregate replacement in mortar. This study is to study on mortar mechanical properties of flexural and compressive strength subjected to elevated temperatures using expanded perlite aggregate (EPA). This study involved experimental work which was developing mortar with sand replacement by volume of 0%, 10%, 20%, 30% and 40% of EPA and cured for 56 days. The mortars then exposed to 200°C, 400 °C, 700 °C and 1000 °C. Flexural and compressive strength of the mortar were tested. The tests showed that there were increased of flexural and compressive strength at 200°C, and constantly decreased when subjected to 400°C, 700°C and 1000 °C. There were also variation of strengths at different percentages of EPA replacement. Highest compressive strength and flexural strength recorded were both at 200 °C with 65.52 MPa and 21.34 MPa respectively. The study conclude that by using EPA as aggregate replacement was ineffective below elevated temperatures but increased the performance of the mortar at elevated temperatures.

Media filter drain : modified design evaluation.

DOT National Transportation Integrated Search

2014-09-01

The media filter drain (MFD), a stormwater water quality treatment best management practice, consists of media made up of : aggregate, perlite, gypsum and dolomite in a trench located along roadway shoulders with gravel and vegetative pre-filtering f...

Immobilization of a Pleurotus ostreatus Laccase Mixture on Perlite and Its Application to Dye Decolourisation

PubMed Central

Salatino, Piero; Sannia, Giovanni

2014-01-01

In the present study, a crude laccase preparation from Pleurotus ostreatus was successfully immobilized on perlite, a cheap porous silica material, and tested for Remazol Brilliant Blue R (RBBR) decolourisation in a fluidized bed recycle reactor. Results showed that RBBR decolourisation is mainly due to enzyme action despite the occurrence of dye adsorption-related enzyme inhibition. Fine tuning of immobilization conditions allowed balancing the immobilization yield and the resulting rate of decolourisation, with the adsorption capacity of the solid biocatalyst. In the continuous lab scale reactor, a maximum conversion degree of 56.1% was achieved at reactor space-time of 4.2 h. Stability and catalytic parameters of the immobilized laccases were also assessed in comparison with the soluble counterparts, revealing an increase in stability, despite a reduction of the catalytic performances. Both effects are most likely ascribable to the occurrence of multipoint attachment phenomena. PMID:24895564

Experimental research in the phase change materials based on paraffin and expanded perlite

NASA Astrophysics Data System (ADS)

Jiesheng, Liu; Faping, Li; Xiaoqiang, Gong; Rongtang, Zhang

2018-06-01

In this study, paraffin (PA)/expanded perlite (EP) form-stable phase change material (PCM) was first fabricated using the direct impregnation method without vacuum treatment. Absorptive capacity results showed that the PA/EP composite can obtain good absorptive capacity with the temperature 80 °C and the time 2 h. Compared with the water absorption of EP, the decrease in the water absorption of PA/EP form-stable proved that the absorption of PA into porous EP has been carried out successfully. Scanning electron microscope (SEM) and Fourier transform infrared (FT-IR) results show that paraffin can be well impregnated into EP pores and has good compatibility with it. Differential scanning calorimetry (DSC) results reveal that paraffin/EP composite PCM has melting temperature and latent heat of 53.6 °C and 91.3 J/g, respectively. The durability cycles results suggest that form-stable PA/EP PCM shows good durability.

Nitrogen availability in composted poultry litter using natural amendments.

PubMed

Turan, N Gamze

2009-02-01

Poultry litter compost is used as fertilizer on agricultural land because of its high nutrient content. A major limitation of land application of poultry litter compost is the loss of nitrogen via NH3 volatilization. The present work was conducted to monitor nitrogen availability during composting of poultry litter with natural zeolite, expanded perlite, pumice and expanded vermiculite. Poultry litter was composted for 100 days using five in-vessel composting simulators with a volumetric ratio of natural materials:poultry litter of 1:10. It was found that natural materials significantly reduced NH3 volatilization. At the end of the process, the control treatment without any natural materials had the lowest rate of total N: 72% of the initial total N was lost from the compost made with no amendment, while 53, 42, 26 and 16% of initial total N was lost from compost containing expandable perlite, expandable vermiculite, pumice and natural zeolite, respectively.

40 CFR 60.16 - Priority list.

Code of Federal Regulations, 2012 CFR

2012-07-01

... production 21. Vegetable Oil 22. Industrial Surface Coating: Metal Coil 23. Petroleum Transportation and... Coating: Automobiles 28. Industrial Surface Coating: Large Appliances 29. Crude Oil and Natural Gas... 53. Starch 54. Perlite 55. Phosphoric Acid: Thermal Process (Deleted) 56. Uranium Refining 57. Animal...

40 CFR 60.16 - Priority list.

Code of Federal Regulations, 2011 CFR

2011-07-01

... production 21. Vegetable Oil 22. Industrial Surface Coating: Metal Coil 23. Petroleum Transportation and... Coating: Automobiles 28. Industrial Surface Coating: Large Appliances 29. Crude Oil and Natural Gas... 53. Starch 54. Perlite 55. Phosphoric Acid: Thermal Process (Deleted) 56. Uranium Refining 57. Animal...

40 CFR 60.16 - Priority list.

Code of Federal Regulations, 2013 CFR

2013-07-01

... production 21. Vegetable Oil 22. Industrial Surface Coating: Metal Coil 23. Petroleum Transportation and... Coating: Automobiles 28. Industrial Surface Coating: Large Appliances 29. Crude Oil and Natural Gas... 53. Starch 54. Perlite 55. Phosphoric Acid: Thermal Process (Deleted) 56. Uranium Refining 57. Animal...

40 CFR 60.16 - Priority list.

Code of Federal Regulations, 2014 CFR

2014-07-01

... production 21. Vegetable Oil 22. Industrial Surface Coating: Metal Coil 23. Petroleum Transportation and... Coating: Automobiles 28. Industrial Surface Coating: Large Appliances 29. Crude Oil and Natural Gas... 53. Starch 54. Perlite 55. Phosphoric Acid: Thermal Process (Deleted) 56. Uranium Refining 57. Animal...

Media filter drain : modified design evaluation and existing design longevity evaluation.

DOT National Transportation Integrated Search

2014-02-01

The media filter drain (MFD), a stormwater water quality treatment best management practice, consists of media made up of : aggregate, perlite, gypsum and dolomite in a trench located along roadway shoulders with gravel and vegetative pre-filtering :...

40 CFR 264.314 - Special requirements for bulk and containerized liquids.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., smectites, Fuller's earth, bentonite, calcium bentonite, montmorillonite, calcined montmorillonite.../hydroxides, alumina, lime, silica (sand), diatomaceous earth; perlite (volcanic glass); expanded volcanic... contain, hazardous waste; and (2) Placement in such owner or operator's landfill will not present a risk...

40 CFR 264.314 - Special requirements for bulk and containerized liquids.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., smectites, Fuller's earth, bentonite, calcium bentonite, montmorillonite, calcined montmorillonite.../hydroxides, alumina, lime, silica (sand), diatomaceous earth; perlite (volcanic glass); expanded volcanic... contain, hazardous waste; and (2) Placement in such owner or operator's landfill will not present a risk...

40 CFR 264.314 - Special requirements for bulk and containerized liquids.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., smectites, Fuller's earth, bentonite, calcium bentonite, montmorillonite, calcined montmorillonite.../hydroxides, alumina, lime, silica (sand), diatomaceous earth; perlite (volcanic glass); expanded volcanic... contain, hazardous waste; and (2) Placement in such owner or operator's landfill will not present a risk...

Strength properties of cement slurries with lightweights applied in oil and gas wells

NASA Astrophysics Data System (ADS)

Bubnov, A. S.; Boyko, I. A.; Khorev, V. S.

2015-02-01

The article is focused on the cement stone strength properties resulted from lightweight cement slurries that meet GOST-1581-96 (state Standards) requirements. Exfoliated vermiculite, hollow aluminosilicate microspheres (HAMs), diatomite and perlite were used as lightweighting additives.

Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

PubMed

Liu, Na; Ding, Feng; Wang, Liu; Liu, Peng; Yu, Xiaolong; Ye, Kang

2016-05-01

A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in <3 days using immobilized consortium, while 3-5 days were required using free cells. The O2 supply efficiency of an enclosed in-well aeration system was assessed in a box filled with perlite and peat. Dissolved O2 (DO) concentrations increased to 8-12 mg L(-1) in 12 h for sampling ports within 12 cm of the aeration well. A diffusion coefficient as 33.5 cm(2) s(-1) was obtained. The DO concentration was >4 mg L(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20 days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

Step-feed biofiltration: a low cost alternative configuration for off-gas treatment.

PubMed

Estrada, José M; Quijano, Guillermo; Lebrero, Raquel; Muñoz, Raúl

2013-09-01

Clogging due to biomass accumulation and the loss of structural stability of the packing media are common operational drawbacks of standard gas biofiltration inherent to the traditional biofilter design, which result in prohibitive pressure drop buildups and media channeling. In this work, an innovative step-feed biofilter configuration, with the air emission supplied in either two or three locations along the biofilter height, was tested and compared with a standard biofilter using toluene as a model pollutant and two packing materials: compost and perlite. When using compost, the step-feed biofilter supported similar elimination capacities (EC ≈ 80 g m(-3) h(-1)) and CO2 production rates (200 g m(-3) h(-1)) to those achieved in the standard biofilter. However, while the pressure drop in the step-feed system remained below 300 Pa m bed(-1) for 61 days, the standard biofilter reached this value in only 14 days and 4000 Pa m bed(-1) by day 30, consuming 75% more compression energy throughout the entire operational period. Operation with perlite supported lower ECs compared to compost in both the step-feed and standard biofilters (≈ 30 g m(-3) h(-1)), probably due to the high indigenous microbial diversity present in this organic packing material. The step-feed biofilter exhibited 65% lower compression energy requirements than the standard biofilter during operation with perlite, while supporting similar ECs. In brief, step-feed biofiltration constitutes a promising operational strategy capable of drastically reducing the operating costs of biofiltration due to a reduced energy consumption and an increased packing material lifespan. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biological Activity Assessment in Mexican Tropical Soils with Different Hydrocarbon Contamination Histories.

PubMed

Riveroll-Larios, Jessica; Escalante-Espinosa, Erika; Fócil-Monterrubio, Reyna L; Díaz-Ramírez, Ildefonso J

The use of soil health indicators linked to microbial activities, such as key enzymes and respirometric profiles, helps assess the natural attenuation potential of soils contaminated with hydrocarbons. In this study, the intrinsic physicochemical characteristics, biological activity and biodegradation potential were recorded for two soils with different contamination histories (>5 years and <1 months). The enzymatic activity (lipase and dehydrogenase) as well as microbiological and mineralisation profiles were measured in contaminated soil samples. Soil suspensions were tested as microbial inocula in biodegradation potential assays using contaminated perlite as an inert support. The basal respiratory rate of the recently contaminated soil was 15-38 mg C-CO 2  kg -1 h -1 , while the weathered soil presented a greater basal mineralisation capacity of 55-70 mg C-CO 2 kg -1 h -1 . The basal levels of lipase and dehydrogenase were significantly greater than those recorded in non-contaminated soils (551 ± 21 μg pNP g -1 ). Regarding the biodegradation potential assessment, the lipase (1000-3000 μg pNP g -1 of perlite) and dehydrogenase (~3000 μg INF g -1 of perlite) activities in the inoculum of the recently contaminated soil were greater than those recorded in the inoculum of the weathered soil. This was correlated with a high mineralisation rate (~30 mg C-CO 2 kg -1 h -1 ) in the recently contaminated soil and a reduction in hydrocarbon concentration (~30 %). The combination of an inert support and enzymatic and respirometric analyses made it possible to detect the different biodegradation capacities of the studied inocula and the natural attenuation potential of a recently contaminated soil at high hydrocarbon concentrations.

The Effects of Light Intensity, Casing Layers, and Layering Styles on Royal Sun Medicinal Mushroom, Agaricus brasiliensis (Higher Basidiomycetes) Cultivation in Turkey.

PubMed

Adanacioglu, Neşe; Boztok, Kaya; Akdeniz, Ramazan Cengiz

2015-01-01

The aim of this research is to evaluate the effects of light intensity, casing layers, and layering styles on the production of the culinary-medicinal mushroom Agaricus brasiliensis in Turkey. The experiments were designed in split-split plots and replicated twice. Three different light intensities-I1, 350 lux; I2, 450 lux; and I3, 750 lux-were used in main plots as environmental factors. A mixture of 4 different casing layers- peat (100%), peat-perlite (75%:25%), peat-clinoptilolite (75%:25%), and peat-perlite-clinoptilolite (60%:20%:20%)-were used at split plots and at split plots. S1, a flat, 3-cm casing layer; S2, a flat, 5-cm casing layer; and S3, casing soil ridges 10 cm wide × 4 cm high, 10 cm apart, were deposited on top of 1-cm overall soil casing layers. At the end of the harvest phase, the total yield was estimated per 100 kg of substrate. Biological efficiency (percentage) was determined from the fresh weight of the mushrooms and the dry weight of the compost at the end of the harvesting period. The highest total yield (7.2 kg/100 kg compost) and biological efficiency (27.63%) were achieved from I2 × peat-perlite-clinoptilolite × S2 treatment. Influence of light intensity, casing layer, layering style, and their interaction in treatments with color values (L*, a*, b*, chroma*, and hue*) also were examined. It has been shown that within color values, chroma* (saturation) values of mushroom caps were affected by light intensity, casing layer, and layering style treatments and light intensity × casing layer treatments and the brightness of mushroom caps tended to increase as light intensity increased.

Parametric Analysis to Study the Influence of Aerogel-Based Renders' Components on Thermal and Mechanical Performance.

PubMed

Ximenes, Sofia; Silva, Ana; Soares, António; Flores-Colen, Inês; de Brito, Jorge

2016-05-04

Statistical models using multiple linear regression are some of the most widely used methods to study the influence of independent variables in a given phenomenon. This study's objective is to understand the influence of the various components of aerogel-based renders on their thermal and mechanical performance, namely cement (three types), fly ash, aerial lime, silica sand, expanded clay, type of aerogel, expanded cork granules, expanded perlite, air entrainers, resins (two types), and rheological agent. The statistical analysis was performed using SPSS (Statistical Package for Social Sciences), based on 85 mortar mixes produced in the laboratory and on their values of thermal conductivity and compressive strength obtained using tests in small-scale samples. The results showed that aerial lime assumes the main role in improving the thermal conductivity of the mortars. Aerogel type, fly ash, expanded perlite and air entrainers are also relevant components for a good thermal conductivity. Expanded clay can improve the mechanical behavior and aerogel has the opposite effect.

Parametric Analysis to Study the Influence of Aerogel-Based Renders’ Components on Thermal and Mechanical Performance

PubMed Central

Ximenes, Sofia; Silva, Ana; Soares, António; Flores-Colen, Inês; de Brito, Jorge

2016-01-01

Statistical models using multiple linear regression are some of the most widely used methods to study the influence of independent variables in a given phenomenon. This study’s objective is to understand the influence of the various components of aerogel-based renders on their thermal and mechanical performance, namely cement (three types), fly ash, aerial lime, silica sand, expanded clay, type of aerogel, expanded cork granules, expanded perlite, air entrainers, resins (two types), and rheological agent. The statistical analysis was performed using SPSS (Statistical Package for Social Sciences), based on 85 mortar mixes produced in the laboratory and on their values of thermal conductivity and compressive strength obtained using tests in small-scale samples. The results showed that aerial lime assumes the main role in improving the thermal conductivity of the mortars. Aerogel type, fly ash, expanded perlite and air entrainers are also relevant components for a good thermal conductivity. Expanded clay can improve the mechanical behavior and aerogel has the opposite effect. PMID:28773460

46 CFR 164.009-3 - Noncombustible materials not requiring specific approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... subpart: (a) Sheet glass, block glass, clay, ceramics, and uncoated fibers. (b) All metals, except... only sand, gravel, expanded vermiculite, expanded or vesicular slags, diatomaceous silica, perlite, or pumice. (d) Woven, knitted or needle punched glass fabric containing no additives other than lubricants...

Using acid-washed waste tire rubber in soilless media for tomato production

USDA-ARS?s Scientific Manuscript database

'Cerasiforne’ tomato (Lycopersicon esculentum Mill.) was grown in soilless potting media contained different substrate formulas including 25:25:50 volume ratio of acid-washed (AWR) or non-washed shredded rubber (NAWR): vermiculite or zeolite: perlite. Additionally, plants were grown in a peat: perli...

Evaluation of biochar-anaerobic potato digestate mixtures as renewable components of horticultural potting media

USDA-ARS?s Scientific Manuscript database

Various formulations are used in horticultural potting media, with sphagnum peat moss, vermiculite and perlite currently among the most common components. We are examining a dried anaerobic digestate remaining after the fermentation of potato processing wastes to replace organic components such as p...

Effect of biochar type on macronutrient retention and release from soilless substrate

USDA-ARS?s Scientific Manuscript database

A series of column studies were conducted to determine the influence of three different biochar types on nitrate, phosphate, and potassium retention and leaching in a typical greenhouse soilless substrate. Glass columns were filled with 85 sphagnum peat moss : 15 perlite (v:v) and amended with 10% ...

Strawberry Production in Soilless Substrate Troughs – Plant Growth

USDA-ARS?s Scientific Manuscript database

Soilless substrates made of peat moss, coconut coir, perlite, rockwool or bark are pathogen free and they have been used in strawberry production in Europe in troughs or containers. Open field strawberry production in soilless substrate is new to California growers. The objective of this study was t...

Microbial Reduction of Chromium from the Hexavalent to Divalent State

DTIC Science & Technology

2007-01-01

address: Center for Materials Innova- strong oxidants which act as carcinogens, mutagens, and tion and Department of Physics , Washington University in...perlite. J. Haz. Mat. B95, 29-46. Kimbrough, D.E., Cohen, Y., Winer, A.M., Creelman , L., Mabuni, C., Chen, J.M., Hao, O.J., 1998. Microbial chromium

Steel slag affects pH and Si content of container substrates

USDA-ARS?s Scientific Manuscript database

A substrate representing a typical greenhouse potting mix was prepared using 85% sphagnum peat and 15% perlite. The substrate was filled into 10 cm wide containers. A pulverized steel slag (SS) from a basic oxygen furnace, and dolomitic limestone (DL) were amended to the base substrate at a rate o...

Evaluating Performance and Stability of Polyethylene Terephthalate (PET) and Cellulose Polymer as Soilless Mix Components

USDA-ARS?s Scientific Manuscript database

In the U.S., concerns over the long-term sustainability of peat, perlite, and other media components have led to searches for alternative materials. FiberFill, a synthetic fiber made of recyclable polyethylene terephthalate, and Tencel, a cellulose fiber, are new materials with potential as substra...

Design of a Field Raised-Bed Trough System using Soilless Substrates for Strawberry Production in California

USDA-ARS?s Scientific Manuscript database

There are a number of approaches for producing strawberry fruit on a commercial scale without fumigants. One possible approach is to grow strawberries using raised-bed troughs filled with non soil based substrate media. Field trials were conducted using peat, perlite, coir, rice hull, and a redwoo...

7 CFR 319.37-8 - Growing media.

Code of Federal Regulations, 2013 CFR

2013-01-01

... shall be free of sand, soil, earth, and other growing media, except as provided in paragraph (b), (c..., coir, cork, glass wool, organic and inorganic fibers, peat, perlite, phenol formaldehyde, plastic... greenhouse must be free from sand and soil and must have screening with openings of not more than 0.6 mm (0.2...

7 CFR 319.37-8 - Growing media.

Code of Federal Regulations, 2014 CFR

2014-01-01

... shall be free of sand, soil, earth, and other growing media, except as provided in paragraph (b), (c..., coir, cork, glass wool, organic and inorganic fibers, peat, perlite, phenol formaldehyde, plastic... greenhouse must be free from sand and soil and must have screening with openings of not more than 0.6 mm (0.2...

7 CFR 319.37-8 - Growing media.

Code of Federal Regulations, 2012 CFR

2012-01-01

... shall be free of sand, soil, earth, and other growing media, except as provided in paragraph (b), (c..., coir, cork, glass wool, organic and inorganic fibers, peat, perlite, phenol formaldehyde, plastic... greenhouse must be free from sand and soil and must have screening with openings of not more than 0.6 mm (0.2...

Modification of the Structure of Low-Carbon Pipe Steel by Helical Rolling, and the Increase in Its Strength and Cold Resistance

NASA Astrophysics Data System (ADS)

Derevyagina, L. S.; Gordienko, A. I.; Pochivalov, Yu. I.; Smirnova, A. S.

2018-01-01

The paper reports the investigation results on the microstructure and mechanical properties of low-carbon pipe steel after helical rolling. The processing of the steel leads to the refinement of ferritic grains from 12 (for the coarse-grained state) to 5 μm, to the strengthening of ferrite by carbide particles, a decrease in the total fraction of perlite grains, a more uniform alternation of ferrite and perlite, and the formation of regions with bainitic structure. The mechanical properties of the steel have been determined in the conditions of static and dynamic loading in the range of test temperatures from +20 to-70°C. As a result of processing, the ultimate tensile strength increases (from 650 to 770 MPa at a rolling temperature from 920°C) and the viscoplastic properties at negative temperatures are improved significantly. The ductile-brittle transition temperature of the rolled steel decreases from-32 to-55°C and the impact toughness at the test temperature-40°C increases eight times compared to the initial state of the steel.

Glass Bubbles Insulation for Liquid Hydrogen Storage Tanks

NASA Astrophysics Data System (ADS)

Sass, J. P.; Cyr, W. W. St.; Barrett, T. M.; Baumgartner, R. G.; Lott, J. W.; Fesmire, J. E.

2010-04-01

A full-scale field application of glass bubbles insulation has been demonstrated in a 218,000 L liquid hydrogen storage tank. This work is the evolution of extensive materials testing, laboratory scale testing, and system studies leading to the use of glass bubbles insulation as a cost efficient and high performance alternative in cryogenic storage tanks of any size. The tank utilized is part of a rocket propulsion test complex at the NASA Stennis Space Center and is a 1960's vintage spherical double wall tank with an evacuated annulus. The original perlite that was removed from the annulus was in pristine condition and showed no signs of deterioration or compaction. Test results show a significant reduction in liquid hydrogen boiloff when compared to recent baseline data prior to removal of the perlite insulation. The data also validates the previous laboratory scale testing (1000 L) and full-scale numerical modeling (3,200,000 L) of boiloff in spherical cryogenic storage tanks. The performance of the tank will continue to be monitored during operation of the tank over the coming years.

Comparing grey water versus tap water and coal ash versus perlite on growth of two plant species on green roofs.

PubMed

Agra, Har'el; Solodar, Ariel; Bawab, Omar; Levy, Shay; Kadas, Gyongyver J; Blaustein, Leon; Greenbaum, Noam

2018-08-15

Green roofs provide important ecosystem services in urban areas. In Mediterranean and other semi-arid climate regions, most perennial plants on green roofs need to be irrigated during the dry season. However, the use of freshwater in such regions is scarce. Therefore, the possibility of using grey water should be examined. Coal ash, produced primarily from the burning of coal in power plants, constitutes an environmental contaminant that should be disposed. One option is to use ash as a growing substrate for plants. Here, we compare the effects of irrigating with grey- versus tap-water and using ash versus perlite as growing substrates in green roofs. The study was conducted in northern Israel in a Mediterranean climate. The design was full factorial with three factors: water-type (grey or tap-water)×substrate-type (coal ash vs perlite)×plant species (Phyla nodiflora, Convolvulus mauritanicus or no-plant). The development of plants and the quality of drainage water along the season, as well as quality of the used substrates were monitored. Both plant species developed well under all the experimental conditions with no effect of water type or substrate type. Under all treatments, both plant species enhanced electrical conductivity (EC) and chemical oxygen demand (COD) of the drainage water. In the summer, EC and COD reached levels that are unacceptable in water and are intended to be reused for irrigation. We conclude that irrigating with grey water and using coal ash as a growth substrate can both be implemented in green roofs. The drainage from tap water as well as from grey water can be further used for irrigating the roof, but for that, COD and EC levels must be lowered by adding a sufficient amount of tap water before reusing. Copyright © 2018 Elsevier B.V. All rights reserved.

Suitability of sphagnum moss, coir, and douglas fir bark as soilless substrates for container production of highbush blueberry

USDA-ARS?s Scientific Manuscript database

The purpose of the present study was to investigate the suitability of different soilless substrates for container production of highbush blueberry (Vaccinium sp.). Young plants of ‘Snowchaser’ blueberry were grown in 4.4-liter pots filled with media containing 10% perlite and varying proportions of...

Reconnaissance geologic map of the Harrat Tuffil Quadrangle, sheet 20/39 B, Kingdom of Saudi Arabia

USGS Publications Warehouse

Pallister, John S.

1983-01-01

A perlite deposit at Jabal Shama may be suitable as light aggregate for concrete. Sparse barite veins were discovered in the lower Shumaysi formation. Relatively small deposits of Sa’diyah formation marble may be of interest for local use in building or cement. The Jurassic dolomite is locally quite pure and may have economic applications.

Prediction of the Effective Thermal Conductivity of Powder Insulation

NASA Astrophysics Data System (ADS)

Jin, Lingxue; Park, Jiho; Lee, Cheonkyu; Jeong, Sangkwon

The powder insulation method is widely used in structural and cryogenic systems such as transportation and storage tanks of cryogenic fluids. The powder insulation layer is constructed by small particle powder with light weight and some residual gas with high porosity. So far, many experiments have been carried out to test the thermal performance of various kinds of powder, including expanded perlite, glass microspheres, expanded polystyrene (EPS). However, it is still difficult to predict the thermal performance of powder insulation by calculation due to the complicated geometries, including various particle shapes, wide powder diameter distribution, and various pore sizes. In this paper, the effective thermal conductivity of powder insulation has been predicted based on an effective thermal conductivity calculationmodel of porous packed beds. The calculation methodology was applied to the insulation system with expanded perlite, glass microspheres and EPS beads at cryogenic temperature and various vacuum pressures. The calculation results were compared with previous experimental data. Moreover, additional tests were carried out at cryogenic temperature in this research. The fitting equations of the deformation factor of the area-contact model are presented for various powders. The calculation results show agood agreement with the experimental results.

Vibration Considerations for Cryogenic Tanks Using Glass Bubbles Insulation

NASA Technical Reports Server (NTRS)

Werlink, Rudolph J.; Fesmire, James E.; Sass, Jared P.

2011-01-01

The use of glass bubbles as an efficient and practical thermal insulation system has been previously demonstrated in cryogenic storage tanks. One such example is a spherical, vacuum-jacketed liquid hydrogen vessel of 218,000 liter capacity where the boiloff rate has been reduced by approximately 50 percent. Further applications may include non-stationary tanks such as mobile tankers and tanks with extreme duty cycles or exposed to significant vibration environments. Space rocket launch events and mobile tanker life cycles represent two harsh cases of mechanical vibration exposure. A number of bulk fill insulation materials including glass bubbles, perlite powders, and aerogel granules were tested for vibration effects and mechanical behavior using a custom design holding fixture subjected to random vibration on an Electrodynamic Shaker. The settling effects for mixtures of insulation materials were also investigated. The vibration test results and granular particle analysis are presented with considerations and implications for future cryogenic tank applications. A thermal performance update on field demonstration testing of a 218,000 L liquid hydrogen storage tank, retrofitted with glass bubbles, is presented. KEYWORDS: Glass bubble, perlite, aerogel, insulation, liquid hydrogen, storage tank, mobile tanker, vibration.

Improvement of In Vitro Date Palm Plantlet Acclimatization Rate with Kinetin and Hoagland Solution.

PubMed

Hassan, Mona M

2017-01-01

In vitro propagation of date palm Phoenix dactylifera L. is an ideal method to produce large numbers of healthy plants with specific characteristics and has the ability to transfer plantlets to ex vitro conditions at low cost and with a high survival rate. This chapter describes optimized acclimatization procedures for in vitro date palm plantlets. Primarily, the protocol presents the use of kinetin and Hoagland solution to enhance the growth of Barhee cv. plantlets in the greenhouse at two stages of acclimatization and the appropriate planting medium under shade and sunlight in the nursery. Foliar application of kinetin (20 mg/L) is recommended at the first stage. A combination between soil and foliar application of 50% Hoagland solution is favorable to plant growth and developmental parameters including plant height, leaf width, stem base diameter, chlorophyll A and B, carotenoids, and indoles. The optimum values of vegetative growth parameters during the adaptation stage in a shaded nursery are achieved using planting medium containing peat moss/perlite 2:1 (v/v), while in a sunlight nursery, clay/perlite/compost at equal ratio is the best. This protocol is suitable for large-scale production of micropropagated date palm plantlets.

Mineral Deposits and Mineral Potential of the China Lake Complex of the Naval Weapons Center, China Lake, California

DTIC Science & Technology

1983-12-01

Tucker and R. J. Sampson. 16 A field check of the area confirmed many of the physical aspects of the property as reported, but the tungsten grades...iron, mercury, perlite, pumice, aggregate, evaporites, travertine, and diatomite . Geothermal and water-producing strata were also investigated. The...Prospect ( Diatomite ) (N-1602) ..... ... 436 Evaporites .......... ....................... .436 Bonanza Group (N-1502) ..... ............... ... 436

Measurements of radioactivity and dose assessments in some building materials in Bitlis, Turkey.

PubMed

Kayakökü, Halime; Karatepe, Şule; Doğru, Mahmut

2016-09-01

In this study, samples of perlite, pumice and Ahlat stones (Ignimbrite) extracted from mines in Bitlis and samples of other building materials produced in facilities in Bitlis were collected and analyzed. Activity concentrations of (226)Ra, (232)Th and (40)K in samples of building materials were measured using NaI detector (NaI(Tl)) with an efficiency of 24%. The radon measurements of building material samples were determined using CR-39 nuclear track detectors. (226)Ra, (232)Th and (40)K radioactivity concentrations ranged from (29.6±5.9 to 228.2±38.1Bq/kg), (10.8±5.4 to 95.5±26.1Bq/kg) and (249.3±124.7 to 2580.1±266.9Bq/kg), respectively. Radon concentration, radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. Radon concentration ranged between 89.2±12.0Bq/m(3) and 1141.0±225.0Bq/m(3). It was determined that Raeq values of samples conformed to world standards except for perlite and single samples of brick and Ahlat stone. Calculated values of absorbed dose rate ranged from 81.3±20.5 to 420.6±42.8nGy/h. ELCR values ranged from (1.8±0.3)×10(-3) to (9.0±1.0)×10(-3). All samples had ELCR values higher than the world average. The values of Hin and Hex varied from 0.35±0.11 to 1.78±0.18 and from 0.37±0.09 to 1.17±0.13, respectively. The results were compared with standard radioactivity values determined by international organizations and with similar studies. There would be a radiation risk for people living in buildings made of perlite, Ahlat-1 and Brick-3. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cellulosic building insulation versus mineral wool, fiberglass or perlite: installer's exposure by inhalation of fibers, dust, endotoxin and fire-retardant additives.

PubMed

Breum, N O; Schneider, T; Jørgensen, O; Valdbjørn Rasmussen, T; Skibstrup Eriksen, S

2003-11-01

A task-specific exposure matrix was designed for workers installing building insulation materials. A priori, a matrix element was defined by type of task (installer or helper), type of work area (attic spaces or wall cavities) and type of insulation material (slabs from mineral wool, fiberglass or flax; loose-fill cellulosic material or perlite). In the laboratory a mock-up (full scale) of a one-family house was used for simulated installation of insulation materials (four replicates per matrix element). Personal exposure to dust and fibers was measured. The dust was analyzed for content of endotoxin and some trace elements (boron and aluminum) from fire-retardant or mold-resistant additives. Fibers were characterized as WHO fibers or non-WHO fibers. In support of the exposure matrix, the dustiness of all the materials was measured in a rotating drum tester. For installers in attic spaces, risk of exposure was low for inhalation of dust and WHO fibers from slab materials of mineral wool or fiberglass. Slab materials from flax may cause high risk of exposure to endotoxin. The risk of exposure by inhalation of dust from loose-fill materials was high for installers in attic spaces and for some of the materials risk of exposure was high for boron and aluminum. Exposure by inhalation of cellulosic WHO fibers was high but little is known about the health effects and a risk assessment is not possible. For the insulation of walls, the risk of installers' exposure by inhalation of dust and fibers was low for the slab materials, while a high risk was observed for loose-fill materials. The exposure to WHO fibers was positively correlated to the dust exposure. A dust level of 6.1 mg/m3 was shown to be useful as a proxy for screening exposure to WHO fibers in excess of 10(6) fibers/m3. In the rotating drum, slabs of insulation material from mineral wool or fiberglass were tested as not dusty. Cellulosic loose-fill materials were tested as very dusty, and perlite proved to be extremely dusty.

Heat-affected zone and phase composition of 0.09 C-2 Mn-1 Si-Fe steel depending on welding technique

NASA Astrophysics Data System (ADS)

Popova, Natalya; Ozhiganov, Eugeniy; Nikonenko, Elena; Ababkov, Nikolay; Smirnov, Aleksander; Koneva, Nina

2017-11-01

The paper presents the transmission electron microscopy (TEM) investigations of the structure and phase composition of the heat-affected zone (HAZ) in welded joint modified by four types of welding, namely: electrode welding and electropercussive welding both with and without the introduction of artificial flaws. Artificial flows are aluminum pieces. TEM investigations are carried out within HAZ between the deposited and base metal at 1 mm distance to the latter. The type 0.09C-2Mn-1Si-Fe steel is used as weld material. It is shown that the welding process has an effect on the material morphology, phase composition, faulted structure and its parameters. Long-range stresses are divided into plastic and elastic components. It is demonstrated that the type of welding does not change the structural quality of welded joint represented by perlite and ferrite as contrasted with their volume fraction. According to observations, any type of welding with the introduction of artificial flaws results in the destruction of perlite. Polarization of the dislocation structure occurs. The amplitude of mean internal stresses does not practically depend on the welding type. It is shown that the introduction of artificial flaws both during electrode and electropercussive welding reduce the quantitative parameters of the faulted structure.

Test of precoat filtration technology for treatment of swimming pool water.

PubMed

Christensen, Morten Lykkegaard; Klausen, Morten Møller; Christensen, Peter Vittrup

2018-02-01

The technical performance of a precoat filter was compared with that of a traditional sand filter. Particle concentration and size distribution were measured before and after the filtration of swimming pool water. Both the sand and precoat filters could reduce the particle concentration in the effluent. However, higher particle removal efficiency was generally observed for the precoat filter, especially for particles smaller than 10 μm in diameter. Adding flocculant improved the removal efficiency of the sand filter, resulting in removal efficiencies comparable to those of the precoat filter. Three powders, i.e., two types of perlite (Harbolite ® and Aquatec perlite) and cellulose fibers (Arbocel ® ), were tested for the precoat filter, but no significant difference in particle removal efficiency was observed among them. The maximum efficiency was reached within 30-40 min of filtration. The energy required for the pumps increased by approximately 35% over a period of 14 days. The energy consumption could be reduced by replacing the powder on the filter cloth. The sand filter was backwashed once a week, while the powder on the precoat filter was replaced every two weeks. Under these conditions, it was possible to reduce the water used for cleaning by 88% if the precoat filter was used instead of the sand filter.

Better Rooting Procedure to Enhance Survival Rate of Field Grown Malaysian Eksotika Papaya Transformed with 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Gene

PubMed Central

Sekeli, Rogayah; Abdullah, Janna Ong; Namasivayam, Parameswari; Muda, Pauziah; Abu Bakar, Umi Kalsom

2013-01-01

A high survival rate for transformed papaya plants when transferred to the field is useful in the quest for improving the commercial quality traits. We report in this paper an improved rooting method for the production of transformed Malaysian Eksotika papaya with high survival rate when transferred to the field. Shoots were regenerated from embryogenic calli transformed with antisense and RNAi constructs of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) genes using the Agrobacterium tumefaciens-mediated transformation method. Regenerated transformed shoots, each measuring approximately 3-4 cm in height, were cultured in liquid half-strength Murashige and Skoog (MS) medium or sterile distilled water, and with either perlite or vermiculite supplementation. All the culturing processes were conducted either under sterile or nonsterile condition. The results showed that rooting under sterile condition was better. Shoots cultured in half-strength MS medium supplemented with vermiculite exhibited a 92.5% rooting efficiency while perlite showed 77.5%. The survival rate of the vermiculite-grown transformed papaya plantlets after transfer into soil, contained in polybags, was 94%, and the rate after transfer into the ground was 92%. Morpho-histological analyses revealed that the tap roots were more compact, which might have contributed to the high survival rates of the plantlets. PMID:25969786

Better rooting procedure to enhance survival rate of field grown malaysian eksotika papaya transformed with 1-aminocyclopropane-1-carboxylic Acid oxidase gene.

PubMed

Sekeli, Rogayah; Abdullah, Janna Ong; Namasivayam, Parameswari; Muda, Pauziah; Abu Bakar, Umi Kalsom

2013-01-01

A high survival rate for transformed papaya plants when transferred to the field is useful in the quest for improving the commercial quality traits. We report in this paper an improved rooting method for the production of transformed Malaysian Eksotika papaya with high survival rate when transferred to the field. Shoots were regenerated from embryogenic calli transformed with antisense and RNAi constructs of 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) genes using the Agrobacterium tumefaciens-mediated transformation method. Regenerated transformed shoots, each measuring approximately 3-4 cm in height, were cultured in liquid half-strength Murashige and Skoog (MS) medium or sterile distilled water, and with either perlite or vermiculite supplementation. All the culturing processes were conducted either under sterile or nonsterile condition. The results showed that rooting under sterile condition was better. Shoots cultured in half-strength MS medium supplemented with vermiculite exhibited a 92.5% rooting efficiency while perlite showed 77.5%. The survival rate of the vermiculite-grown transformed papaya plantlets after transfer into soil, contained in polybags, was 94%, and the rate after transfer into the ground was 92%. Morpho-histological analyses revealed that the tap roots were more compact, which might have contributed to the high survival rates of the plantlets.

Solid-state fermentation as a potential technique for esterase/lipase production by halophilic archaea.

PubMed

Martin del Campo, Martha; Camacho, Rosa M; Mateos-Díaz, Juan C; Müller-Santos, Marcelo; Córdova, Jesus; Rodríguez, Jorge A

2015-11-01

Halophilic archaea are extremophiles, adapted to high-salt environments, showing a big biotechnological potential as enzyme, lipids and pigments producers. Four inert supports (perlite, vermiculite, polyurethane foam and glass fiber) were employed for solid-state fermentation (SSF) of the halophilic archaeon Natronococcus sp. TC6 to investigate biomass and esterase production. A very low esterase activity and high water activity were observed when perlite, vermiculite and polyurethane were used as supports. When glass fiber was employed, an important moisture loss was observed (8.6%). Moreover, moisture retention was improved by mixing polyurethane and glass fiber, resulting in maximal biomass and esterase production. Three halophilic archaea: Natronococcus sp. TC6, Halobacterium sp. NRC-1 and Haloarcula marismortui were cultured by submerged fermentation (SmF) and by SSF; an improvement of 1.3- to 6.2-fold was observed in the biomass and esterase production when SSF was used. Growth was not homogeneous in the mixture, but was predominant in the glass fiber thus was probably because the glass fiber provides a holder to the cells, while the polyurethane acts as an impregnation medium reservoir. To the best of our knowledge, this work is the first report on haloarchaea cultivation by SSF aiming biomass and esterase/lipase activity production.

Respiratory Disease Related Mortality and Morbidity on an Island of Greece Exposed to Perlite and Bentonite Mining Dust

PubMed Central

Sampatakakis, Stefanos; Linos, Athena; Papadimitriou, Eleni; Petralias, Athanasios; Dalma, Archontoula; Papasaranti, Eirini Saranti; Christoforidou, Eleni; Stoltidis, Melina

2013-01-01

A morbidity and mortality study took place, focused on Milos Island, where perlite and bentonite mining sites are located. Official data concerning number and cause of deaths, regarding specific respiratory diseases and the total of respiratory diseases, for both Milos Island and the Cyclades Prefecture were used. Standardized Mortality Ratios (SMRs) were computed, adjusted specifically for age, gender and calendar year. Tests of linear trend were performed. By means of a predefined questionnaire, the morbidity rates of specific respiratory diseases in Milos, were compared to those of the municipality of Oinofita, an industrial region. Chi-square analysis was used and the confounding factors of age, gender and smoking were taken into account, by estimating binary logistic regression models. The SMRs for Pneumonia and Chronic Obstructive Pulmonary Disease (COPD) were found elevated for both genders, although they did not reach statistical significance. For the total of respiratory diseases, a statistically significant SMR was identified regarding the decade 1989–1998. The morbidity study revealed elevated and statistically significant Odds Ratios (ORs), associated with allergic rhinitis, pneumonia, COPD and bronchiectasis. An elevated OR was also identified for asthma. After controlling for age, gender and smoking, the ORs were statistically significant and towards the same direction. PMID:24129114

Aerogel Beads as Cryogenic Thermal Insulation System

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Augustynowicz, S. D.; Rouanet, S.; Thompson, Karen (Technical Monitor)

2001-01-01

An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/cubic m) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(exp -5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress.

The measurement of enamel and dentine abrasion by tooth whitening products using an in situ model.

PubMed

Joiner, A; Collins, L Z; Cox, T F; Pickles, M J; Weader, E; Liscombe, C; Holt, J S

2005-01-01

To determine the enamel and dentine wear of two whitening toothpastes using an in situ model with ex vivo brushing. Human enamel/dentine (approximately 50:50) blocks (approximately 4 x 4mm) were placed in the upper buccal aspects of full or partial dentures of a group of 25 subjects. Subjects brushed the specimens ex vivo with either a calcium carbonate/perlite or silica containing whitening toothpaste under exaggerated conditions as compared to normal for 30 s, twice per day. Specimens were removed after 4, 8 and 12 weeks and the wear to the enamel and dentine was determined. Enamel wear was determined by change in Knoop indent length and dentine wear was determined from the enamel-dentine step height, measured using optical profilometry. The mean wear after 12 weeks was for enamel 0.27 and 0.19 microns, and for dentine 34.3 and 61.1 microns, for the calcium carbonate/perlite and silica toothpastes respectively. There were no significant differences between products after 12 weeks. The rate of wear was found to decrease throughout the duration of the study. There were no significant differences between the two whitening toothpastes in terms of enamel and dentine wear after 12 weeks brushing.

The influence of partial replacement of hemp shives by expanded perlite on physical properties of hemp-lime composite

NASA Astrophysics Data System (ADS)

Brzyski, Przemysław; Widomski, Marcin

2017-07-01

The use of waste plants in building materials production is consistent with the principles of sustainable development, including waste management, CO2 balance, biodegradability of the material e.g. after building demolition. The porous structure of plant materials determines their usability as the insulation materials. An example of plant applicable in the construction industry is the industrial hemp. The shives are produced from the wooden core of the hemp stem as lightweight insulating filler in the composite based on lime binder. The discussed hemp-lime composite, due to the presence of lightweight, porous organic aggregates exhibits satisfactory thermal insulation properties and is used as filling and insulation of walls (as well as roofs and floors) in buildings of the wooden frame construction. The irregular shape of shives and their low density causes nonhomogenous compaction of composite and the formation of voids between the randomly arranged shives. In this paper the series of hemp-lime composites were tested. Apart from hemp shives, an additional aggregate - expanded perlite was used as a fine, lightweight, thermal insulating filler. Application of the additional aggregate was aimed to fill the voids between hemp shives and to investigate its influence on the physical properties of composite: apparent density, total porosity, water absorption and thermal conductivity.

Changes in growth, essential oil yield and composition of geranium (Pelargonium graveolens L.) as affected by growing media.

PubMed

Rezaei Nejad, Abdolhossein; Ismaili, Ahmad

2014-03-30

Using proper growing medium is known to be an effective way to improve crop growth and yield. However, the effects of growing media on geranium essential oil have scarcely ever been examined in detail. In this research, the effects of different growing media (soil, sand, pumice, perlite and perlite + cocopeat) on growth, oil yield and composition of geranium were studied. Growth was significantly improved in soilless-grown plants compared with soil-grown plants. Oil yield of soilless-grown plants (except for pumice) was about threefold higher than that of soil-grown plants. The increase in oil yield was correlated with higher leaf dry weight (r²  = 0.96), as oil content was not affected. The citronellol/geranium ratio of oil was clearly affected by growing media, ranging from 5:1 in soil culture to 3:1 in soilless culture. The latter is acceptable for perfumery. Compared with soil, soilless media could produce higher yields of high-quality geranium oil that fits market requirements. Growth, oil yield and composition of plants grown in sand (a cheap and abundant growing medium) were not significantly different from those of plants grown in perlite and perlite + cocopeat. © 2013 Society of Chemical Industry.

Respiratory disease related mortality and morbidity on an island of Greece exposed to perlite and bentonite mining dust.

PubMed

Sampatakakis, Stefanos; Linos, Athena; Papadimitriou, Eleni; Petralias, Athanasios; Dalma, Archontoula; Papasaranti, Eirini Saranti; Christoforidou, Eleni; Stoltidis, Melina

2013-10-14

A morbidity and mortality study took place, focused on Milos Island, where perlite and bentonite mining sites are located. Official data concerning number and cause of deaths, regarding specific respiratory diseases and the total of respiratory diseases, for both Milos Island and the Cyclades Prefecture were used. Standardized Mortality Ratios (SMRs) were computed, adjusted specifically for age, gender and calendar year. Tests of linear trend were performed. By means of a predefined questionnaire, the morbidity rates of specific respiratory diseases in Milos, were compared to those of the municipality of Oinofita, an industrial region. Chi-square analysis was used and the confounding factors of age, gender and smoking were taken into account, by estimating binary logistic regression models. The SMRs for Pneumonia and Chronic Obstructive Pulmonary Disease (COPD) were found elevated for both genders, although they did not reach statistical significance. For the total of respiratory diseases, a statistically significant SMR was identified regarding the decade 1989-1998. The morbidity study revealed elevated and statistically significant Odds Ratios (ORs), associated with allergic rhinitis, pneumonia, COPD and bronchiectasis. An elevated OR was also identified for asthma. After controlling for age, gender and smoking, the ORs were statistically significant and towards the same direction.

Oil palm waste and synthetic zeolite: an alternative soil-less growth substrate for lettuce production as a waste management practice.

PubMed

Jayasinghe, Guttila Y; Tokashiki, Yoshihiro; Kitou, Makato; Kinjo, Kazutoshi

2008-12-01

A study was conducted to assess the characteristics and the prospective utilization of oil palm waste (OP) and synthetic zeolite (SZ) developed by coal fly ash, as an alternative substrate to peat and commercial perlite for lettuce (Lactuca sativa L.) production. The SZ, OP, sphagnum peat (PE), perlite (PL) and two different SZ-OP mixtures (v/v) at the ratio of 1 : 3 and 1 : 10 were utilized as the substrates under this study. The substrates formulated by mixing SZ with OP at the ratio of 1 : 3 and 1 : 10 showed improved substrate physical and chemical properties such as air space, bulk density, particle density, water-holding capacity, pH and electrical conductivity (EC), which were in the ideal substrate range when compared with PL. Furthermore, the water-holding capacity of the substrate having a 1 : 10 mixing ratio of SZ with OP was higher than that of the PL by 28.23%, whereas the bulk density was lower than that of PL by 35%. A greenhouse experiment was carried out to assess the influence of the substrates on the growth and development of lettuce. The shoot fresh weight, shoot dry weight, root fresh weight, root dry weight and number of leaves per plant of the lettuce grown in the 1 : 10 mixing ratio of SZ and OP were the highest, which showed increased values compared with that of PL by 11.56, 9.77, 3.48, 17.35 and 16.53%, respectively. The shoot fresh weight, shoot dry weight, root fresh weight, root dry weight and number of leaves per plant of the lettuce grown in the 1 : 10 mixing ratio of SZ and OP showed increased percentages compared with that of PE by 12.12, 11.37, 3.74, 23.66 and 17.50%, respectively. In addition, the growth and yield parameters of lettuce grown in the 1 : 3 mixing ratio and the OP did not show any significant difference with PL and PE but differed from the 1 : 10 mixing ratio. The results of the study suggest that the SZ-OP-based substrates and OP can be successfully utilized as alternatives to the commercial perlite and to substitute the conventional peat substrate for lettuce cultivation. In addition, this can be proposed as an alternative waste management practice.

Building Energy Storage Panel Based on Paraffin/Expanded Perlite: Preparation and Thermal Performance Study.

PubMed

Kong, Xiangfei; Zhong, Yuliang; Rong, Xian; Min, Chunhua; Qi, Chengying

2016-01-25

This study is focused on the preparation and performance of a building energy storage panel (BESP). The BESP was fabricated through a mold pressing method based on phase change material particle (PCMP), which was prepared in two steps: vacuum absorption and surface film coating. Firstly, phase change material (PCM) was incorporated into expanded perlite (EP) through a vacuum absorption method to obtain composite PCM; secondly, the composite PCM was immersed into the mixture of colloidal silica and organic acrylate, and then it was taken out and dried naturally. A series of experiments, including differential scanning calorimeter (DSC), scanning electron microscope (SEM), best matching test, and durability test, have been conducted to characterize and analyze the thermophysical property and reliability of PCMP. Additionally, the thermal performance of BESP was studied through a dynamic thermal property test. The results have showed that: (1) the surface film coating procedure can effectively solve the leakage problem of composite phase change material prepared by vacuum impregnation; (2) the optimum adsorption ratio for paraffin and EP was 52.5:47.5 in mass fraction, and the PCMP has good thermal properties, stability, and durability; and (3) in the process of dynamic thermal performance test, BESP have low temperature variation, significant temperature lagging, and large heat storage ability, which indicated the potential of BESP in the application of building energy efficiency.

Electroadsorption of acilan blau dye from textile effluents by using activated carbon-perlite mixtures.

PubMed

Koparal, A S; Yavuz, Y; Bakir Ogütveren, U

2002-01-01

The feasibility of the removal of dye stuffs from textile effluents by electroadsorption has been investigated. An activated carbon-perlite mixture with a ratio of 8:1 for bipolarity has been used as the adsorbent. Conventional adsorption experiments have also been conducted for comparison. A bipolar trickle reactor has been used in the electroadsorption experiments. The model wastewater has been prepared by using acilan blau dye. Initial dye concentration, bed height between the electrodes, applied potential, flowrate, and the supporting electrolyte concentration have been examined as the parameters affecting the removal efficiency. A local textile plant effluent has been treated in the optimum values of these parameters obtained from the experimental studies. Adsorption kinetics and the amount of adsorbent required to reach the maximum removal efficiency have also been investigated and mass-transfer coefficients have been calculated for adsorption and electroadsorption. The results showed that a removal efficiency of up to 100% can be achieved with energy consumption values of 1.58 kWh/m3 of wastewater treated. However, energy consumption decreases to 0.09 kWh/m3 if an exit dye concentration of 4.65 mg/L is accepted. It can be concluded from this work that this method combines all of the advantages of the activated-carbon adsorption and electrolytic methods for the removal of dyes from wastewater.

Building Energy Storage Panel Based on Paraffin/Expanded Perlite: Preparation and Thermal Performance Study

PubMed Central

Kong, Xiangfei; Zhong, Yuliang; Rong, Xian; Min, Chunhua; Qi, Chengying

2016-01-01

This study is focused on the preparation and performance of a building energy storage panel (BESP). The BESP was fabricated through a mold pressing method based on phase change material particle (PCMP), which was prepared in two steps: vacuum absorption and surface film coating. Firstly, phase change material (PCM) was incorporated into expanded perlite (EP) through a vacuum absorption method to obtain composite PCM; secondly, the composite PCM was immersed into the mixture of colloidal silica and organic acrylate, and then it was taken out and dried naturally. A series of experiments, including differential scanning calorimeter (DSC), scanning electron microscope (SEM), best matching test, and durability test, have been conducted to characterize and analyze the thermophysical property and reliability of PCMP. Additionally, the thermal performance of BESP was studied through a dynamic thermal property test. The results have showed that: (1) the surface film coating procedure can effectively solve the leakage problem of composite phase change material prepared by vacuum impregnation; (2) the optimum adsorption ratio for paraffin and EP was 52.5:47.5 in mass fraction, and the PCMP has good thermal properties, stability, and durability; and (3) in the process of dynamic thermal performance test, BESP have low temperature variation, significant temperature lagging, and large heat storage ability, which indicated the potential of BESP in the application of building energy efficiency. PMID:28787870

Catalytic pyrolysis of car tire waste using expanded perlite.

PubMed

Kar, Y

2011-08-01

In this study, the non-catalytic and catalytic pyrolysis experiments were conducted on the sample of tire waste using expanded perlite as an additive material to determine especially the effect of temperature and catalyst-to-tire ratio on the products yields and the compositions and qualities of pyrolytic oils (NCPO and CPO). Non-catalytic studies, which were carried out under the certain conditions (a nitrogen flow of 100mL/min and a heating rate of 10°C/min), showed that the highest yield of pyrolytic oil (NCPO) was 60.02wt.% at 425°C. Then, the catalytic pyrolysis studies were carried out at catalyst-to-tire ratio range of 0.05-0.25 and the highest catalytic pyrolytic oil (CPO) yield was 65.11wt.% at the ratio of 0.10 with the yield increase of 8.48wt.% compared with the non-catalytic pyrolysis. Lastly, the pyrolytic oils were characterized with applying a various techniques such as elemental analyses and various chromatographic and spectroscopic techniques (GC-MS, (1)H NMR, FT-IR, etc.). The characterization results revealed that the pyrolytic oils which were complex mixtures of C(5)-C(15) organic compounds (predominantly aromatic compounds) and also the CPO compared to the NCPO was more similar to conventional fuels in view of the certain fuel properties. Copyright © 2011 Elsevier Ltd. All rights reserved.

Removal of petroleum hydrocarbons from contaminated groundwater by the combined technique of adsorption onto perlite followed by the O3/H2O2 process.

PubMed

Moussavi, Gholamreza; Bagheri, Amir

2012-09-01

Groundwater contaminated with petroleum hydrocarbons was treated using a combined system of adsorption onto powdered expanded perlite (PEP) followed by the O3/H2O2 process. The pretreatment investigations indicated a high capacity for PEP to remove petroleum hydrocarbons from the contaminated water. An experimental total petroleum hydrocarbon (TPH) adsorption capacity of 275 mg/g PEP was obtained at the natural pH of water. The experimental data fit best with the Freundlich isotherm model and pseudo-second-order adsorption model. The second phase of the experiment evaluated the performance of the O3/H2O2 process in the removal of residual TPH from pretreated water and compared the results with that of raw water. The O3/H202 process attained a maximum TPH removal rate for the pretreated water after 70 min, when 93% of the residual TPH in the effluent of the adsorption system was removed. Overall, the combination of adsorption onto PEP for 100 min and the subsequent treatment with the O3/H2O2 process for 70min eliminated over 99% of the TPH of highly petroleum-contaminated groundwater, with initial values of 162 mg/L. Therefore, we can conclude that the developed treatment system is an appropriate method of remediation for petroleum-contaminated waters.

Diagnosis of a Poorly Performing Liquid Hydrogen Bulk Storage Sphere

NASA Technical Reports Server (NTRS)

Krenn, Angela G.

2011-01-01

There are two 850,000 gallon Liquid Hydrogen (LH2) storage spheres used to support the Space Shuttle Program; one residing at Launch Pad A and the other at Launch Pad B. The LH2 Sphere at Pad B has had a high boiloff rate since being brought into service in the 1960's. The daily commodity loss was estimated to be approximately double that of the Pad A sphere, and well above the minimum required by the sphere's specification. Additionally, after being re-painted in the late 1990's a "cold spot" appeared on the outer sphere which resulted in a poor paint bond, and mold formation. Thermography was used to characterize the area, and the boiloff rate was continually evaluated. All evidence suggested that the high boiloff rate was caused by an excessive heat leak into the inner sphere due to an insulation void in the annulus. Pad B was recently taken out of Space Shuttle program service which provided a unique opportunity to diagnose the sphere's poor performance. The sphere was drained and inerted, and then opened from the annular relief device on the top where a series of boroscoping operations were accomplished. Boroscoping revealed a large Perlite insulation void in the region of the sphere where the cold spot was apparent. Perlite was then trucked in and off-loaded into the annular void region until the annulus was full. The sphere has not yet been brought back into service.

Hydrological performance of dual-substrate-layer green roofs using porous inert substrates with high sorption capacities.

PubMed

Wang, Xiaoou; Tian, Yimei; Zhao, Xinhua; Peng, Chenrui

2017-06-01

Given that the common medium in existing green roofs is a single layer composed of organic and inorganic substrates, seven pilot-scale dual-substrate-layer extensive green roofs (G1-G7), which include nutrition and adsorption substrate layers, were constructed in this study. The effectiveness of porous inert substrates (activated charcoal, zeolite, pumice, lava, vermiculite and expanded perlite) used as the adsorption substrate for stormwater retention was investigated. A single-substrate-layer green roof (G8) was built for comparison with G1-G7. Despite the larger total rainfall depth (mm) of six types of simulated rains (43.2, 54.6, 76.2, 87.0, 85.2 and 86.4, respectively), the total percent retention of G1-G7 varied between 14% and 82% with an average of 43%, exhibiting better runoff-retaining capacity than G8 based on the maximum potential rainfall storage depth per unit height of adsorption substrate. Regression analysis showed that there was a logarithmic relationship between cumulative rainfall depth with non-zero runoff and stormwater retention for G1-G4 and a linear relationship for G5-G8. To enhance the water retention capacity and extend the service life of dual-substrate-layer extensive green roofs, the mixture of activated charcoal and/or pumice with expanded perlite and/or vermiculite is more suitable as the adsorption substrate than the mixture containing lava and/or zeolite.

Improvement of home composting process of food waste using different minerals.

PubMed

Margaritis, M; Psarras, K; Panaretou, V; Thanos, A G; Malamis, D; Sotiropoulos, A

2018-03-01

This article presents the experimental study of the process of composting in a prototype home-scale system with a special focus on process improvement by using different additives (i.e. woodchips, perlite, vermiculite and zeolite). The interventions with different bulking agents were realized through composting cycles using substrates with 10% additives in specific mixtures of kitchen waste materials. The pre-selected proportion of the mixtures examined was 3:1:1 in cellulosic:proteins:carbohydrates, in order to achieve an initial C/N ratio equal to 30. The control of the initial properties of the examined substrates aimed at the consequent improvement of the properties of the final product (compost). The results indicated that composting process was enhanced with the use of additives and especially the case of zeolite and perlite provided the best results, in terms of efficient temperature evolution (>55 °C for 4 consecutive days). Carbon to nitrogen ratios decreased by 40% from the initial values for the reactors were minerals were added, while for the bioreactor tested with woodchips the reduction was slight, showing slowest degradation rate. Moisture content of produced compost varied within the range of 55-64% d.m., while nutrient content (K, Na, Ca, Mg) was in accordance with the limit values reported in literature. Finally, the composts obtained, exhibited a satisfactory degree of maturity, fulfilling the criterion related to the absence of phytotoxic compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mineral Resources of the Warm Springs Wilderness Study Area, Mohave County, Arizona

USGS Publications Warehouse

Gray, Floyd; Jachens, Robert C.; Miller, Robert J.; Turner, Robert L.; Knepper, Daniel H.; Pitkin, James A.; Keith, William J.; Mariano, John; Jones, Stephanie L.; Korzeb, Stanley L.

1986-01-01

At the request of the U.S. Bureau of Land Management, approximately 113,500 acres of the Warm Springs Wilderness Study Area (AZ-020-028/029) were evaluated for mineral resources and mineral resource potential. In this report, the area studied is referred to as the 'wilderness study area' or 'study area'; any reference to the Warm Springs Wilderness Study Area refers only to that part of the wilderness study area for which a mineral survey was requested. This study area is located in west-central Arizona. The U.S. Geological Survey and the U.S. Bureau of Mines conducted geological, geochemical, and geophysical surveys to appraise the identified mineral resources (known) and assess the mineral resource potential (undiscovered) of the study area. fieldwork for this report was carried out largely in 1986-1989. There is a 1-million short ton indicated subeconomic resource of clinoptilolite-mordenite zeolite and an additional inferred resource of 2 million short tons near McHeffy Butte, approximately 2 miles west of the study area. A perlite deposit in the southeast corner of the study area contains an inferred subeconomic resource totaling 13 million short tons. An inferred subeconomic resource of gold in 225 short tons of quartz having a grade of 0.01 8 troy ounces per short ton is present at the Cook mine, 0.5 miles west of the study area. The northwestern part of the Warm Springs Wilderness Study Area has high mineral resource potential for gold and silver. The south-central part of the study area has one area of moderate and one area north of this south-central part has low mineral resource potential for gold and silver in and near Warm Springs Canyon; the mineral resource potential for gold is also moderate in three small areas in the southern part and one area in the northeastern part of the study area. The mineral resource potential for zeolite is high for the area surrounding the McHeffy Butte prospect and for one area in the southern part of the study area. Two areas inside the south and southeast boundaries of the study area have high mineral resource potential for perlite. The potential for ka: olinite resources is moderate in two areas in the southern part of the study area. The southern part of the study area has low resource potential for perlite and zeolite. Geothermal energy resource potential of the study area is low. The study area has no resource potential for oil and gas.

Toughening Effect of Microscale Particles on the Tensile and Vibration Properties of S-Glass-Fiber-Reinforced Epoxy Composites

NASA Astrophysics Data System (ADS)

Erkliğ, A.; Bulut, M.; Fayzulla, B.

2018-03-01

The effect of borax, sewage sludge ash, silicon carbide, and perlite microparticles on the tensile, damping, and vibration characteristics of S-glass/epoxy composite laminates was examined Their damping and vibration properties were evaluated experimentally by using the dynamic modal analysis, identifying the response of the fundamental natural frequency to the type and weight content of the particulates. The results obtained showed that the introduction of specific amounts of such particulates into the matrix of S-glass/epoxy composite noticeably improved its mechanical properties.

Ternary binder based plasters with improved thermal insulating ability

NASA Astrophysics Data System (ADS)

Čáchová, M.; Koňáková, D.; Vejmelková, E.; Vyšvařil, M.

2017-10-01

New kind of plasters with improved thermal insulating ability are presented in this article. Improvement was reached by utilization of lightweight expanded perlite with high porosity. The second used aggregate was silica sand. Regarding the binder, three kind were combined for the reason of better plaster performance. Pure lime, Portland cement and pozzolanic ceramic powder were employed. Basic physical properties and thermal characteristics were determined. The porosity of plasters reached desired higher value about 50% and the thermal conductivity in dry state was lower than 0.16 Wm-1K-1.

Visible-light-driven, water-surface-floating antimicrobials developed from graphitic carbon nitride and expanded perlite for water disinfection.

PubMed

Zhang, Chi; Li, Yi; Shuai, Danmeng; Zhang, Wenlong; Niu, Lihua; Wang, Longfei; Zhang, Huanjun

2018-05-28

Waterborne pathogens, especially bacteria and viruses, pose significant health risks to the public, calling for the development of a sustainable, efficient, and robust disinfection strategy with reduced energy footprint and minimized byproduct formation. Here, we developed a sustainable photocatalytic composite for antimicrobial applications by integrating visible-light-responsive graphitic carbon nitride (g-C 3 N 4 ) with low-density porous expanded perlite (EP) mineral, and g-C 3 N 4 /EP-520 showed a high specific surface area of 45.3 m 2 /g and optimum performance for disinfection. g-C 3 N 4 /EP-520 achieved 8-log inactivation of E. coli and MS2 under 180 and 240 min visible-light irradiation without stirring, respectively. Water quality parameters were found to influence the disinfection performance of g-C 3 N 4 /EP-520: MS2 inactivation was promoted with the increase of dissolved oxygen (DO), proton concentration, salinity (NaCl), and hardness (Ca 2+ ). Importantly, g-C 3 N 4 /EP-520 could fully inactivate MS2 in a real source water sample with prolonged light irradiation, and negligible activity loss was observed in recycle use, demonstrating its viability and robustness for waterborne pathogen removal. Antimicrobial mechanisms of g-C 3 N 4 /EP-520 were systemically evaluated by radical scavenger addition, and revealed that the inactivation behavior was dependent on the type of microorganisms. Microscopic analyses confirmed that the destruction of bacterial cells and viral particles, leading to the inactivation of microorganisms. Copyright © 2018 Elsevier Ltd. All rights reserved.

The safe removal of frozen air from the annulus of an LH2 storage tank

NASA Astrophysics Data System (ADS)

Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

2015-12-01

Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modelling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

Preparation, Mechanical and Thermal Properties of Cement Board with Expanded Perlite Based Composite Phase Change Material for Improving Buildings Thermal Behavior

PubMed Central

Ye, Rongda; Fang, Xiaoming; Zhang, Zhengguo; Gao, Xuenong

2015-01-01

Here we demonstrate the mechanical properties, thermal conductivity, and thermal energy storage performance of construction elements made of cement and form-stable PCM-Rubitherm® RT 28 HC (RT28)/expanded perlite (EP) composite phase change materials (PCMs). The composite PCMs were prepared by adsorbing RT28 into the pores of EP, in which the mass fraction of RT28 should be limited to be no more than 40 wt %. The adsorbed RT28 is observed to be uniformly confined into the pores of EP. The phase change temperatures of the RT28/EP composite PCMs are very close to that of the pure RT28. The apparent density and compression strength of the composite cubes increase linearly with the mass fraction of RT28. Compared with the thermal conductivity of the boards composed of cement and EP, the thermal conductivities of the composite boards containing RT28 increase by 15%–35% with the mass fraction increasing of RT28. The cubic test rooms that consist of six boards were built to evaluate the thermal energy storage performance, it is found that the maximum temperature different between the outside surface of the top board with the indoor temperature using the composite boards is 13.3 °C higher than that of the boards containing no RT28. The thermal mass increase of the built environment due to the application of composite boards can contribute to improving the indoor thermal comfort and reducing the energy consumption in the buildings. PMID:28793671

Cryogenic Storage Tank Non-Destructive Evaluation

NASA Technical Reports Server (NTRS)

Arens, Ellen

2010-01-01

This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

The Safe Removal of Frozen Air from the Annulus of an LH2 Storage Tank

NASA Technical Reports Server (NTRS)

Krenn, A.; Starr, S.; Youngquist, R.; Nurge, M.; Sass, J.; Fesmire, J.; Cariker, C.; Bhattacharya, A.

2015-01-01

Large Liquid Hydrogen (LH2) storage tanks are vital infrastructure for NASA. Eventually, air may leak into the evacuated and perlite filled annular region of these tanks. Although the vacuum level is monitored in this region, the extremely cold temperature causes all but the helium and neon constituents of air to freeze. A small, often unnoticeable pressure rise is the result. As the leak persists, the quantity of frozen air increases, as does the thermal conductivity of the insulation system. Consequently, a notable increase in commodity boil-off is often the first indicator of an air leak. Severe damage can result from normal draining of the tank. The warming air will sublimate which will cause a pressure rise in the annulus. When the pressure increases above the triple point, the frozen air will begin to melt and migrate downward. Collection of liquid air on the carbon steel outer shell may chill it below its ductility range, resulting in fracture. In order to avoid a structural failure, as described above, a method for the safe removal of frozen air is needed. A thermal model of the storage tank has been created using SINDA/FLUINT modeling software. Experimental work is progressing in an attempt to characterize the thermal conductivity of a perlite/frozen nitrogen mixture. A statistical mechanics model is being developed in parallel for comparison to experimental work. The thermal model will be updated using the experimental/statistical mechanical data, and used to simulate potential removal scenarios. This paper will address methodologies and analysis techniques for evaluation of two proposed air removal methods.

Preparation, Mechanical and Thermal Properties of Cement Board with Expanded Perlite Based Composite Phase Change Material for Improving Buildings Thermal Behavior.

PubMed

Ye, Rongda; Fang, Xiaoming; Zhang, Zhengguo; Gao, Xuenong

2015-11-13

Here we demonstrate the mechanical properties, thermal conductivity, and thermal energy storage performance of construction elements made of cement and form-stable PCM-Rubitherm® RT 28 HC (RT28)/expanded perlite (EP) composite phase change materials (PCMs). The composite PCMs were prepared by adsorbing RT28 into the pores of EP, in which the mass fraction of RT28 should be limited to be no more than 40 wt %. The adsorbed RT28 is observed to be uniformly confined into the pores of EP. The phase change temperatures of the RT28/EP composite PCMs are very close to that of the pure RT28. The apparent density and compression strength of the composite cubes increase linearly with the mass fraction of RT28. Compared with the thermal conductivity of the boards composed of cement and EP, the thermal conductivities of the composite boards containing RT28 increase by 15%-35% with the mass fraction increasing of RT28. The cubic test rooms that consist of six boards were built to evaluate the thermal energy storage performance, it is found that the maximum temperature different between the outside surface of the top board with the indoor temperature using the composite boards is 13.3 °C higher than that of the boards containing no RT28. The thermal mass increase of the built environment due to the application of composite boards can contribute to improving the indoor thermal comfort and reducing the energy consumption in the buildings.

EFFECTS OF DIFFERENT HYDROPONIC SUBSTRATE COMBINATIONS AND WATERING REGIMES ON PHYSIOLOGICAL AND ANTI-FUNGAL PROPERTIES OF SIPHONOCHILUS AETHIOPICUS

PubMed Central

S, Xego; L, Kambizi; F, Nchu

2017-01-01

Background: Production of medicinal plants in controlled environments, particularly hydroponic technology, provides opportunities for high quality biomass accumulation and optimizes production of secondary metabolites. Applying special watering regimes in combination with efficient soil draining is an encouraging new tool for the production of pharmaceutical relevant plants. The purpose of this paper was to evaluate the effect of substrate combinations and watering regimes on nutrient uptake, anti-F. oxysporum activity and secondary metabolite profile of S. aethiopicus. Materials and Methods: Coir was used as the main component for the preparation of media in different combinations; TI (Coir + vermiculite + perlite + bark), T2 (Coir + bark), T3 (Coir + perlite) and T4 (Coir + vermiculite). Plants in different treatments were grown under two watering regimes: 3 and 5-days watering intervals. At 9 weeks post treatment, plants were harvested, oven dried and tissue nutrient content, anti-F. oxysporum activity and secondary metabolites were analyzed. Results: The results showed that there were significant differences (P < 0.05) on the uptake of P, K, N, Mg, Fe, Cu, B and NH4-.The highest mean values for most nutrients were obtained in treatments under 3-days interval. Acetone extracts of S. aethiopicus under 5-days interval were the most bioactive against F. oxysporum. The MIC values obtained are relatively lower for the rhizomes, ranging from 0.078 - 0.3125 mg/ml compared to the higher MIC values (0.375 - 0.75 mg/ml) obtained in the leaves. LC-MS analysis of acetone extracts revealed the presence of phytochemicals such as caffeic acid, quercetin, p-hydroxybenzoic acid, rutin, kaempferol, epicatechin, naringenin, hesperetin and protocatechuic acid. Conclusion: The antimicrobial activity and/or the phytochemical profile of the crude extracts were affected by watering regimes. PMID:28480420

A Study on a Novel Phase Change Material Panel Based on Tetradecanol/Lauric Acid/Expanded Perlite/Aluminium Powder for Building Heat Storage

PubMed Central

Wang, Enyu; Kong, Xiangfei; Rong, Xian; Yao, Chengqiang; Yang, Hua; Qi, Chengying

2016-01-01

Phase change material (PCM) used in buildings can reduce the building energy consumption and indoor temperature fluctuation. A composite PCM has been fabricated by the binary eutectic mixture of tetradecanol (TD) and lauric acid (LA) absorbed into the expanded perlite (EP) using vacuum impregnation method, and its thermal conductivity was promoted by aluminium powder (AP) additive. Besides, the styrene-acrylic emulsion has been mixed with the composite PCM particles to form the protective film, so as to solve the problem of leakage. Thus, a novel PCM panel (PCMP) has been prepared using compression moulding forming method. The thermal property, microstructure characteristic, mechanical property, thermal conductivity, thermal reliability and leakage of the composite PCM have been investigated and analysed. Meanwhile, the thermal performance of the prepared PCMP was tested through PCMPs installed on the inside wall of a cell under outdoor climatic conditions. The composite PCM has a melting temperature of 24.9 °C, a freezing temperature of 25.2 °C, a melting latent heat of 78.2 J/g and a freezing latent heat of 81.3 J/g. The thermal conductivity test exposed that the thermal conductivity has been enhanced with the addition of AP and the latent heat has been decreased, but it still remains in a high level. The leakage test result has proven that liquid PCM leaking has been avoided by the surface film method. The thermal performance experiment has shown the significant function of PCMP about adjusting the indoor temperature and reducing the heats transferring between the wall inside and outside. In view of the thermal performance, mechanical property and thermal reliability results, it can be concluded that the prepared PCMP has a promising building application potential. PMID:28774020

Removal of alpha-pinene from gases using biofilters containing fungi

NASA Astrophysics Data System (ADS)

van Groenestijn, J. W.; Liu, J. X.

Biofiltration is cost-effective for the treatment of gases containing low concentrations of volatile organic compounds (<3 g m -3) . However, conventional biofilters, based on compost and bacterial activity, face problems with the elimination of hydrophobic compounds. Besides that, biofilter operational stability is often hampered by acidification and drying out of the filter bed. To overcome these problems, biofilters with fungi on inert packing material have been developed. Fungi are more resistant to acid and dry conditions than bacteria, and it is hypothesised that the aerial mycelia of fungi, which are in direct contact with the gas, can take up hydrophobic compounds faster than flat aqueous bacterial biofilm surfaces. Alpha-pinene was chosen as a model compound. It is an odorous compound emitted by the wood processing industry. In 2 l biofilter columns four different packing materials were tested: perlite, expanded clay granules, polyurethane foam cubes and compost. The filters were inoculated with forest soil and ventilated with gas containing alpha-pinene. Start up took 1-2 months and removal efficiencies of more than 90% were observed, but mostly ranged from 50% to 90% due to overloading. In the filters containing perlite, clay, polyurethane and compost volumetric removal capacities of, respectively, 24, 33, 38 and 24 g alpha- pinene m -3 filter bed h -1 were attained and the gas pressure drops in the 60 cm high filter beds measured at a superficial gas velocity of 35 m h -1 were 70, 550, 180 and 250 Pa. The results indicate that it is possible to develop biofilters based on the action of fungi with higher elimination capacities for alpha-pinene as reported in literature for bacterial biofilters. The use of polyurethane foam cubes is preferred because of the low gas pressure drop in combination with a high volumetric elimination capacity.

EFFECTS OF DIFFERENT HYDROPONIC SUBSTRATE COMBINATIONS AND WATERING REGIMES ON PHYSIOLOGICAL AND ANTI-FUNGAL PROPERTIES OF SIPHONOCHILUS AETHIOPICUS.

PubMed

S, Xego; L, Kambizi; F, Nchu

2017-01-01

Production of medicinal plants in controlled environments, particularly hydroponic technology, provides opportunities for high quality biomass accumulation and optimizes production of secondary metabolites. Applying special watering regimes in combination with efficient soil draining is an encouraging new tool for the production of pharmaceutical relevant plants. The purpose of this paper was to evaluate the effect of substrate combinations and watering regimes on nutrient uptake, anti- F. oxysporum activity and secondary metabolite profile of S. aethiopicus . Coir was used as the main component for the preparation of media in different combinations; TI (Coir + vermiculite + perlite + bark), T2 (Coir + bark), T3 (Coir + perlite) and T4 (Coir + vermiculite). Plants in different treatments were grown under two watering regimes: 3 and 5-days watering intervals. At 9 weeks post treatment, plants were harvested, oven dried and tissue nutrient content, anti- F. oxysporum activity and secondary metabolites were analyzed. The results showed that there were significant differences ( P < 0.05) on the uptake of P, K, N, Mg, Fe, Cu, B and NH4 - .The highest mean values for most nutrients were obtained in treatments under 3-days interval. Acetone extracts of S. aethiopicus under 5-days interval were the most bioactive against F. oxysporum . The MIC values obtained are relatively lower for the rhizomes, ranging from 0.078 - 0.3125 mg/ml compared to the higher MIC values (0.375 - 0.75 mg/ml) obtained in the leaves. LC-MS analysis of acetone extracts revealed the presence of phytochemicals such as caffeic acid, quercetin, p-hydroxybenzoic acid, rutin, kaempferol, epicatechin, naringenin, hesperetin and protocatechuic acid. The antimicrobial activity and/or the phytochemical profile of the crude extracts were affected by watering regimes.

Performance evaluation of a slow-release packing material-embedded functional microorganisms for biofiltration.

PubMed

Zhu, Rencheng; Li, Shunyi; Wu, Zhenjun; Dumont, Éric

2017-04-01

A composite packing material (CM-5) was prepared in this study, mainly consisting of compost with functional microorganisms, calcium carbonate (CaCO 3 ), perlite, cement and plant fiber. To get stronger compressive strength, mass ratios of these components were optimized based on single factor experiments, and finally adding amounts of perlite, cement, plant fiber, CaCO 3 , compost and binder at 18%, 18%, 7%, 13%, 17% and 27%, respectively. According to the optimum proportion, CM-5 was extruded in cylindrical shape (12 mm in diameter and 20 mm in length) with a bulk density of 470 kg m -3 , a moisture retention capacity of 49% and the microbial counts of × 10 5 CFU g -1 of packing material. The cumulative release rates of total organic carbon (TOC) and total nitrogen (TN) from CM-5 were 3.1% and 6.5%, respectively, after 19 times extraction in distilled water. To evaluate the H 2 S removal capacity, CM-5 was compared with an organic (corncob) and an inorganic (ceramsite) packing material in three biofilters. The results showed that CM-5 had higher H 2 S removal capacity compared with corncob and ceramsite. CM-5 could avoid the large fluctuation of pH value and pressure drop during the operation. The maximum H 2 S removal capacity of CM-5 was 12.9 g m -3  h -1 and the removal efficiency could maintain over 95.4% when the inlet H 2 S loading rate was lower than 11.3 g m -3  h -1 without any addition of nutrients and pH buffer substances. Besides, only 2-3 days were needed for the recovery of biofiltration performance after about two weeks of idle period.

Heat Transfar Properties of Flat-Panel Evacuated Porous Insrlators

NASA Astrophysics Data System (ADS)

Yoneno, Hirosyi; Yamamoto, Ryoichi

Flat Panel evacuated porous insulators have been produced by filling powder or fiber (such as perlite powder, diatomaceous earth powder, silica aerogel powder, g lass fiber and ceramic fiber) in film-like laminated plastic container and by evacuating to form vacuum in it is interior. Heat transfer properties of these evacuated insulators have been studied under various conditions (such as particle diameter, surface area, packing density, solid volume fraction and void dimension). The apparent mean thermal conductivity has been measured for the boundary surface temperature at cold face temperature 13°C and hot face temperature 35°. The effect of air pressure ranging from 1 Pa to one atomosphere (105 Pa) was examined. The results were as follows. (1) For each powder the apparent mean thermal conductivity decreases with decreasing residual air pressure, and at very low pressure bellow 1 -103 Pa the conductivity becomes indeqendent of pressure. The thermal conductivity at 1.3Pa is 0.0053 W/mK for perlite powder, 0.0048W/mK for diatomaceous earth powder, 0.0043 W/mK for silica aerogel powder and 0.0029W/mK for glass fiber. (2) With decreasing particle size, the apparent mean thermal conductivity is constant independent of residual air pressure in higher pressure region. It is that void dimension continues to decrease with particle size and the mean free path of air becomes comparable with void dimension. (3) In the range of minor solid volume fraction, the apparent mean thermal conductivity at very low precreases with decreasing particle size. This shows the thermal contact resistance of the solid particle increases with decreasing particle size.

Review on sugar beet salt stress studies in Iran

NASA Astrophysics Data System (ADS)

Khayamim, S.; Noshad, H.; Jahadakbar, M. R.; Fotuhi, K.

2017-07-01

Increase of saline lands in most regions of the world and Iran, limit of production increase based on land enhancement and also threat of saline water and soils for crop production make related researches and production of salt tolerant variety to be more serious. There have been many researches about salt stress in Sugar Beet Seed Institute of Iran (SBSI) during several years. Accordingly, the new screening methods for stress tolerance to be continued based on these researches. Previous researches in SBSI were reviewed and results concluded to this study which is presented in this article in three categories including: Agronomy, Breeding and Biotechnology. In agronomy researches, suitable planting medium, EC, growth stage and traits for salinity tolerance screening were determined and agronomic technique such as planting date, planting method and suitable nutrition for sugar beet under salt stress were introduced. Sand was salinizied by saline treatments two times more than Perlit so large sized Perlit is suitable medium for saline studies. Sugar beet genotypes screening for salt tolerance and should be conducted at EC=20 in laboratory and EC= 16 dS/M in greenhouse. Although sugar beet seed germination has been known as more susceptible stage to salinity, it seems establishment is more susceptible than germination in which salinity will cause 70-80% decrease in plant establishment. Measurements of leaves Na, K and total carbohydrate at establishment stage would be useful for faster screening of genotypes, based on high and significant correlation of these traits at establishment with yield at harvest time. In breeding section, SBSI genotypes with drought tolerance background would be useful for salinity stress studies and finally there is a need for more research in the field of biotechnology in Iran.

Reduction of heat insulation upon soaking of the insulation layer

NASA Astrophysics Data System (ADS)

Achtliger, J.

1983-09-01

Improved thermal protection of hollow masonry by introduction of a core insulation between the inner and outer shell is discussed. The thermal conductivity of insulation materials was determined in dry state and after soaking by water with different volume-related moisture contents. The interpolated thermal conductivity values from three measured values at 10 C average temperature are presented as a function of the pertinent moisture content. Fills of expanded polystyrene, perlite and granulated mineral fibers, insulating boards made of mineral fibers and in situ cellular plastics produced from urea-formaldehyde resin were investigated. Test results show a confirmation of thermal conductivity values for insulating materials in hollow masonry.

USSR and Eastern Europe Scientific Abstracts Engineering and Equipment No.29

DTIC Science & Technology

1977-02-08

Perlite (12CrlMoV and 12Cr2MoVSib), ferrite - martensite (lCrllW2MoV), and austentite (Crl8Nil2Ti) steels are discussed for use in the heat-transfer...620°C. Other austentite steels have been developed, including EI695R, EP184, EP17, 45Crl0Mnl4Al-2 (which has a 20-40% ferrite phase ), 0Crl3Mnl2Ni2NSi2...middle zone of 10 mm and at the corners -- up to 40 mm. The shell was reinforced with a grid having square meshes of low -carbon steel wire, 1 mm in diam

Mineral resources of the Devil's Garden Lava Bed, Squaw Ridge Lava Bed, and Four Craters Lava Bed Wilderness Study Areas, Lake County, Oregon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keith, W.J.; King, H.D.; Gettings, M.E.

1988-01-01

The Devel's Garden lava Bed, Squaw Ridge Lava Bed, and Four Craters Lava Bed Wilderness Study Areas include approximately 70,940 acres and are underlain entirely by Pleistocene or Holocene lava flows and associated sediments. There is no evidence of hydrothermal alteration in the study areas. No resources were identified in the study areas, but there is low potential for perlite resources in the southern part of the Devil's Garden Lava Bed and the northern half of the Squaw Ridge Lava Bed areas. All three study areas have low potential for geothermal resources and for oil and gas resources.

Wool-waste as organic nutrient source for container-grown plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheljazkov, Valtcho D.; Stratton, Glenn W.; Pincock, James

A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) inmore » pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and basil tissue N, and NO{sub 3}-N and NH{sub 4}-N in growth medium relative to the unamended control. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis of wool fibers sampled at the end of the experiments indicated various levels of decomposition, with some fibers retaining their original surface structure. Furthermore, most of the wool fibers' surfaces contained significant concentrations of S and much less N, P, or K. SEM/EDX revealed that some plant roots grow directly on wool-waste fibers suggesting either (1) root directional growth towards sites with greater nutrient concentration and/or (2) a possible role for roots or root exudates in wool decomposition. Results from this study suggest that uncomposted wool wastes can be used as soil amendment, growth medium constituent, and nutrient source for container-grown plants.« less

Localized application of soil organic matter shifts distribution of cluster roots of white lupin in the soil profile due to localized release of phosphorus

PubMed Central

Li, Hai-Gang; Shen, Jian-Bo; Zhang, Fu-Suo; Lambers, Hans

2010-01-01

Background and Aims Phosphorus (P) is a major factor controlling cluster-root formation. Cluster-root proliferation tends to concentrate in organic matter (OM)-rich surface-soil layers, but the nature of this response of cluster-root formation to OM is not clear. Cluster-root proliferation in response to localized application of OM was characterized in Lupinus albus (white lupin) grown in stratified soil columns to test if the stimulating effect of OM on cluster-root formation was due to (a) P release from breakdown of OM; (b) a decrease in soil density; or (c) effects of micro-organisms other than releasing P from OM. Methods Lupin plants were grown in three-layer stratified soil columns where P was applied at 0 or 330 mg P kg−1 to create a P-deficient or P-sufficient background, and OM, phytate mixed with OM, or perlite was applied to the top or middle layers with or without sterilization. Key Results Non-sterile OM stimulated cluster-root proliferation and root length, and this effect became greater when phytate was supplied in the presence of OM. Both sterile OM and perlite significantly decreased cluster-root formation in the localized layers. The OM position did not change the proportion of total cluster roots to total roots in dry biomass among no-P treatments, but more cluster roots were concentrated in the OM layers with a decreased proportion in other places. Conclusions Localized application of non-sterile OM or phytate plus OM stimulated cluster-root proliferation of L. albus in the localized layers. This effect is predominantly accounted for by P release from breakdown of OM or phytate, but not due to a change in soil density associated with OM. No evidence was found for effects of micro-organisms in OM other than those responsible for P release. PMID:20150198

Development of a terrestrial vertebrate model for assessing bioavailability of cadmium in the fence lizard (Sceloporus undulatus) and in ovo effects on hatchling size and thyroid function.

PubMed

Brasfield, Sandra M; Bradham, Karen; Wells, Jason B; Talent, Larry G; Lanno, Roman P; Janz, David M

2004-03-01

In the terrestrial environment, standardized protocols are available for measuring the exposure and effects of contaminants to invertebrates, but none currently exist for vertebrates. In an effort to address this, we proposed that developing lizard embryos may be used as a terrestrial vertebrate model. Lizard eggs may be particularly susceptible to soil contamination and in ovo exposure may affect hatchling size, mortality, as well as thyroid function. Toxicant-induced perturbations of thyroid function resulting from in ovo chemical exposure may result in toxicity during the critical perinatal period in reptiles. Fertilized Eastern fence lizard (Sceloporus undulatus) eggs were placed in cadmium (Cd)-spiked expanded perlite (0, 1.48, 14.8, 148, 1480, 14,800 microg Cd/g, nominal concentrations), artificially incubated at 28 degrees C, and examined daily for mortality. Whole lizard hatchlings as well as failed hatches were homogenized in ethanol and the homogenate was divided for Cd body residue analysis and thyroid hormone (triiodothyronine (T3) and thyroxine (T4)) analyses. Acute mortality was observed in the two highest doses (1480 and 14800 microg Cd/g). Cadmium body residues showed a higher internal concentration with increasing exposure concentration indicating uptake of Cd. There was a decrease in T3:T4 ratio at the highest surviving dose (148 microg Cd/g), however, there were no differences observed in hatchling size measured as weight and snout-vent length, or in whole body thyroid hormone levels. In summary, this study has shown Cd amended to a solid phase representing soil (perlite) can traverse the thin, parchment-like shell membrane of the fence lizard egg and bioaccumulate in lizard embryos. We believe this study is a good first step in investigating and evaluating this species for use as a model.

Screening of faba bean (Vicia faba L.) accessions to acidity and aluminium stresses

PubMed Central

Stoddard, Frederick L.

2017-01-01

Background Faba bean is an important starch-based protein crop produced worldwide. Soil acidity and aluminium toxicity are major abiotic stresses affecting its production, so in regions where soil acidity is a problem, there is a gap between the potential and actual productivity of the crop. Hence, we set out to evaluate acidity and aluminium tolerance in a range of faba bean germplasm using solution culture and pot experiments. Methods A set of 30 accessions was collected from regions where acidity and aluminium are or are not problems. The accessions were grown in solution culture and a subset of 10 was grown first in peat and later in perlite potting media. In solution culture, morphological parameters including taproot length, root regrowth and root tolerance index were measured, and in the pot experiments the key measurements were taproot length, plant biomass, chlorophyll concentration and stomatal conductance. Result Responses to acidity and aluminium were apparently independent. Accessions Dosha and NC 58 were tolerant to both stress. Kassa and GLA 1103 were tolerant to acidity showing less than 3% reduction in taproot length. Aurora and Messay were tolerant to aluminium. Babylon was sensitive to both, with up to 40% reduction in taproot length from acidity and no detectable recovery from Al3+ challenge. Discussion The apparent independence of the responses to acidity and aluminium is in agreement with the previous research findings, suggesting that crop accessions separately adapt to H+ and Al3+ toxicity as a result of the difference in the nature of soil parent materials where the accession originated. Differences in rankings between experiments were minor and attributable to heterogeneity of seed materials and the specific responses of accessions to the rooting media. Use of perlite as a potting medium offers an ideal combination of throughput, inertness of support medium, access to leaves for detection of their stress responses, and harvest of clean roots for evaluation of their growth. PMID:28194315

Screening of faba bean (Vicia faba L.) accessions to acidity and aluminium stresses.

PubMed

Belachew, Kiflemariam Y; Stoddard, Frederick L

2017-01-01

Faba bean is an important starch-based protein crop produced worldwide. Soil acidity and aluminium toxicity are major abiotic stresses affecting its production, so in regions where soil acidity is a problem, there is a gap between the potential and actual productivity of the crop. Hence, we set out to evaluate acidity and aluminium tolerance in a range of faba bean germplasm using solution culture and pot experiments. A set of 30 accessions was collected from regions where acidity and aluminium are or are not problems. The accessions were grown in solution culture and a subset of 10 was grown first in peat and later in perlite potting media. In solution culture, morphological parameters including taproot length, root regrowth and root tolerance index were measured, and in the pot experiments the key measurements were taproot length, plant biomass, chlorophyll concentration and stomatal conductance. Responses to acidity and aluminium were apparently independent. Accessions Dosha and NC 58 were tolerant to both stress. Kassa and GLA 1103 were tolerant to acidity showing less than 3% reduction in taproot length. Aurora and Messay were tolerant to aluminium. Babylon was sensitive to both, with up to 40% reduction in taproot length from acidity and no detectable recovery from Al 3+ challenge. The apparent independence of the responses to acidity and aluminium is in agreement with the previous research findings, suggesting that crop accessions separately adapt to H + and Al 3+ toxicity as a result of the difference in the nature of soil parent materials where the accession originated. Differences in rankings between experiments were minor and attributable to heterogeneity of seed materials and the specific responses of accessions to the rooting media. Use of perlite as a potting medium offers an ideal combination of throughput, inertness of support medium, access to leaves for detection of their stress responses, and harvest of clean roots for evaluation of their growth.

Geology of Saipan, Mariana Islands; Part 2, Petrology and soils

USGS Publications Warehouse

Schmidt, R.G.; Johnson, J. H.; McCracken, R.J.

1957-01-01

The rocks that comprise the volcanic formations of Saipan are of two principal types: dacites, which are characteristically glassy, and andesites, which are comparatively crystalline. The dacites consist primarily of silicic glass, oligoclase, and silica minerals (quartz, tridymite, cristobalite, chalcedony, and opal). Minor constituents in these rocks are green hornblende, biotite, magnetite, and hematite. The andesites are composed principally of labradorite, hypersthene, augite, and subcalcrc augite. Minor but also characteristic constituents of the andesites are quartz, tridymite, cristobalite, anorthoclase, and accessory magnetite, ilmenite, rutile, and apatite. Nine varieties of dacite and andesite are recognized on the basis of chemical composition, mineralogy, and texture. These are dacite, dacite vitrophyre, dacite perlite, hornblende-bearing dacite porphyry, augite-hypersthene andesite, quartz-bearing augite-hypersthene andesite, quartz-bearing augite-hypersthene andesite porphyry, augite andesite, and hypersthene andesite.

Pad B Liquid Hydrogen Storage Tank

NASA Technical Reports Server (NTRS)

Hall, Felicia

2007-01-01

Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

The regulation of crystalline silica: an industry perspective.

PubMed

Elzea, J M

1997-01-01

Silica is ubiquitous in the earth's crust. It occurs in trace to large quantities in rocks and soil. Because it is so common, the regulation of silica has affected a large number of industries, including the mining industry and any industry that uses quartz in the manufacture of a products. Mineral commodities that contain silica include diatomite, bentonite, kaolinite, talc, pyrophyllite, sand and gravel, perlite, pumice, dimension stone, and barite. Products that contain minerals, many of which are associated with silica, include paint, paper, rubber, plastic, pharmaceuticals, food, cement, plaster, cat litter, potting soil, plaster board, and miscellaneous construction materials. In collaboration with some agencies and academic centers, the silica industry is supporting research to lower health risks and to improve the methods of detecting this common material.

Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

NASA Astrophysics Data System (ADS)

Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

2008-03-01

Thermal conductivity testing under actual-use conditions is a key to understanding how cryogenic thermal insulation systems perform in regard to engineering, economics, and materials factors. The Cryogenics Test Laboratory at NASA's Kennedy Space Center tested a number of bulk-fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boiloff method were 78 K and 293 K. Tests were performed as a function of cold vacuum pressure under conditions ranging from high vacuum to no vacuum. Results were compared with those from complementary test methods in the range of 20 K to 300 K. Various testing techniques are required to completely understand the operating performance of a material and to provide data for answers to design engineering questions.

Summary of Activities for Nondestructive Evaluation of Insulation in Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Arens, Ellen

2012-01-01

This project was undertaken to investigate methods to non-intrusively determine the existence and density of perlite insulation in the annular region of the cryogenic storage vessels, specifically considering the Launch Complex 39 hydrogen tanks at Kennedy Space Center. Lack of insulation in the tanks (as existed in the pad B hydrogen tank at Kennedy Space Center) results in an excessive loss of commodity and can pose operational and safety risks if precautions are not taken to relieve the excessive gas build-up. Insulation with a density that is higher than normal (due to settling or compaction) may also pose an operational and safety risk if the insulation prevents the system from moving and responding to expansions and contractions as fluid is removed and added to the tank.

Factors Affecting the Levels of Heavy Metals in Juices Processed with Filter Aids.

PubMed

Wang, Zhengfang; Jackson, Lauren S; Jablonski, Joseph E

2017-06-01

This study investigated factors that may contribute to the presence of arsenic and other heavy metals in apple and grape juices processed with filter aids. Different types and grades of filter aids were analyzed for arsenic, lead, and cadmium with inductively coupled plasma-tandem mass spectrometry. Potential factors affecting the transfer of heavy metals to juices during filtration treatments were evaluated. Effects of washing treatments on removal of heavy metals from filter aids were also determined. Results showed that diatomaceous earth (DE) generally contained a higher level of arsenic than perlite, whereas perlite had a higher lead content than DE. Cellulose contained the lowest level of arsenic among the surveyed filter aids. All samples of food-grade filter aids contained arsenic and lead levels that were below the U.S. Pharmacopeia and National Formulary limits of 10 ppm of total leachable arsenic and lead for food-grade DE filter aids. Two samples of arsenic-rich (>3 ppm) food-grade filter aids raised the level of arsenic in apple and grape juices during laboratory-scale filtration treatments, whereas three samples of low-arsenic (<1 ppm) food-grade filter aids did not affect arsenic levels in filtered juices. Filtration tests with simulated juices (pH 2.9 to 4.1, Brix [°Bx] 8.2 to 18.1, total suspended solids [TSS] 0.1 to 0.5%) showed that pH or sugar content had no effect on arsenic levels of filtered juices, whereas arsenic content of filtered juice was elevated when higher amounts of filter aid were used for filtration. Authentic unfiltered apple juice (pH 3.6, °Bx 12.9, TSS 0.4%) and grape juice (pH 3.3, °Bx 16.2, TSS 0.05%) were used to verify results obtained with simulated juices. However, body feed ratio did not affect the arsenic content of filtered authentic juices. Washing treatments were effective at reducing arsenic, but not cadmium or lead, concentrations in a DE filter aid. This study identified ways to reduce the amount of arsenic transferred to juices during filtration.

The influence of dual-substrate-layer extensive green roofs on rainwater runoff quantity and quality.

PubMed

Wang, Xiaoou; Tian, Yimei; Zhao, Xinhua

2017-08-15

This study investigates the ability of dual-substrate-layer extensive green roofs to retain rainwater and reduce pollutant leaching. The substrates in dual-substrate-layer green roofs consist of an upper organic nutrition layer for plant growth and a lower inorganic adsorption layer for water retention and pollutant reduction. One traditional single-substrate-layer extensive green roof was built for comparison with dual-substrate-layer green roofs. During the experimental period, dual-substrate-layer green roofs supported better natural vegetation growth, with coverage exceeding 90%, while the coverage in single-substrate-layer green roof was over 80%. Based on the average retention value of the total rainfall for four types of simulated rains (the total rainfall depth (mm) was 43.2, 54.6, 76.2 and 86.4, respectively), the dual-substrate-layer green roofs, which used the mixture of activated charcoal with perlite and vermiculite as the adsorption substrate, possessed better rainfall retention performance (65.9% and 55.4%) than the single-substrate-layer green roof (52.5%). All of the dual-substrate-layer green roofs appeared to be sinks for organics, heavy metals and all forms of nitrogen in all cases, while acted as sources of phosphorus contaminants in the case of heavy rains. In consideration of the factors of water retention, pollution reduction and service life of the green roof, a mixture of activated charcoal and/or pumice with perlite and vermiculite is recommended as the adsorption substrate. The green roofs were able to mitigate mild acid rain, raising the pH from approximately 5.6 in rainfall to 6.5-7.6 in green roof runoff. No signs of a first flush effect for phosphate, total phosphorus, ammonia nitrogen, nitrate nitrogen, total nitrogen, organics, zinc, lead, chromium, manganese, copper, pH or turbidity were found in the green roof runoff. Cost analysis further proved the practicability of dual-substrate-layer green roofs in retaining rainwater, and their long-term rainwater runoff quantity and quality performance in urban environments merit further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

New high-capacity, calcium-based sorbents, calcium silicate sorbents. Final report, 1993--August 31, 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenney, M.C.; Chiang, R.K.; Fillgrove, K.L.

1995-02-01

A search is being carried out for new calcium-based S0{sub 2} sorbents for induct injection. More specifically, a search is being carried out for induct injection calcium silicate sorbents that are highly cost effective. The objectives for the current year include the study of sorbents made from Ca(OH){sub 2}, from mixtures of Ca(OH){sub 2} and SiO{sub 2}, and from portland cement. They also include the study of sorbents made from model compounds. During this year, sorbents prepared from Ca(OH){sub 2} and from mixtures of Ca(OH){sub 2} and fumed SiO{sub 2} were investigated. The results show that very good SiO{sub 2}-modifiedmore » Ca(OH){sub 2} sorbents in which the Si-to-Ca reactant ratio is low can be prepared from Ca(OH){sub 2} and fumed SiO{sub 2}. Sorbents prepared from Ca(OH){sub 2} and natural SiO{sub 2} or natural SiO{sub 2} sources were also studied. The results obtained show that very good SiO{sub 2}-modified Ca(OH){sub 2} sorbents and calcium silicate hydrate sorbents, C-S-H sorbents, can be prepared from Ca(OH){sub 2} and diatomite, pumice or perlite, minerals that are readily available. In addition. sorbents prepared from Ca{sub 3}SiO{sub 5} and {beta}-Ca{sub 2}SiO{sub 4} and from mixtures of these compounds and SiO{sub 2} were studied. The results secured demonstrate that very good C-S-H rich sorbents can be prepared from these compounds and from mixtures of them with SiO{sub 2}. They also provide information useful for interpreting the cement sorbent results. Sorbents prepared from cement and from mixtures of cement and natural SiO{sub 2} or SiO{sub 2} sources were investigated as well. The results secured show that cement and mixtures of it with diatomite, pumice or perlite rapidly yield excellent sorbents with the proper reaction conditions.« less

Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate.

PubMed

Valeeva, Lia R; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R; Shakirov, Eugene V

2018-01-01

Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo -inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2 . The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future crop biotechnologies involving such enzymes will require a very careful evaluation of phytase source and activity. Overall, our data suggest feasibility of using bacterial phytases to improve plant growth in conditions of phosphorus deficiency and demonstrate that inducible expression of recombinant enzymes should be investigated further as a viable approach to plant biotechnology.

Heterologous Expression of Secreted Bacterial BPP and HAP Phytases in Plants Stimulates Arabidopsis thaliana Growth on Phytate

PubMed Central

Valeeva, Lia R.; Nyamsuren, Chuluuntsetseg; Sharipova, Margarita R.; Shakirov, Eugene V.

2018-01-01

Phytases are specialized phosphatases capable of releasing inorganic phosphate from myo-inositol hexakisphosphate (phytate), which is highly abundant in many soils. As inorganic phosphorus reserves decrease over time in many agricultural soils, genetic manipulation of plants to enable secretion of potent phytases into the rhizosphere has been proposed as a promising approach to improve plant phosphorus nutrition. Several families of biotechnologically important phytases have been discovered and characterized, but little data are available on which phytase families can offer the most benefits toward improving plant phosphorus intake. We have developed transgenic Arabidopsis thaliana plants expressing bacterial phytases PaPhyC (HAP family of phytases) and 168phyA (BPP family) under the control of root-specific inducible promoter Pht1;2. The effects of each phytase expression on growth, morphology and inorganic phosphorus accumulation in plants grown on phytate hydroponically or in perlite as the only source of phosphorus were investigated. The most enzymatic activity for both phytases was detected in cell wall-bound fractions of roots, indicating that these enzymes were efficiently secreted. Expression of both bacterial phytases in roots improved plant growth on phytate and resulted in larger rosette leaf area and diameter, higher phosphorus content and increased shoot dry weight, implying that these plants were indeed capable of utilizing phytate as the source of phosphorus for growth and development. When grown on phytate the HAP-type phytase outperformed its BPP-type counterpart for plant biomass production, though this effect was only observed in hydroponic conditions and not in perlite. Furthermore, we found no evidence of adverse side effects of microbial phytase expression in A. thaliana on plant physiology and seed germination. Our data highlight important functional differences between these members of bacterial phytase families and indicate that future crop biotechnologies involving such enzymes will require a very careful evaluation of phytase source and activity. Overall, our data suggest feasibility of using bacterial phytases to improve plant growth in conditions of phosphorus deficiency and demonstrate that inducible expression of recombinant enzymes should be investigated further as a viable approach to plant biotechnology. PMID:29515604

Influence of relative humidity on the properties of examined materials by means of inverse gas chromatography.

PubMed

Strzemiecka, Beata; Kołodziejek, Joanna; Kasperkowiak, Małgorzata; Voelkel, Adam

2013-01-04

Inverse gas chromatography (IGC) at infinite dilution was applied to evaluate the surface properties of sorbents and the effect of different carrier gas humidity. They were stored in different environmental humidity - 29%, 40%, and 80%. The dispersive components of the surface free energy of the zeolites and perlite were determined by Schulz-Lavielle method, whereas their tendency to undergo specific interactions was estimated basing on the electron donor-acceptor approach presented by Flour and Papirer. Surface parameters were used to monitor the changes of the properties caused by the humidity of the storage environment as well as of RH of carrier gas. The increase of humidity of storage environment caused a decrease of sorbents surface activity and increase the ability to specific interaction. Copyright © 2012 Elsevier B.V. All rights reserved.

Developments in advanced and energy saving thermal isolations for cryogenic applications

NASA Astrophysics Data System (ADS)

Shu, Q. S.; Demko, J. A.; Fesmire, J. E.

2015-12-01

The cooling power consumption in large scale superconducting systems is huge and cryogenic devices used in space applications often require an extremely long cryogen holding time. To economically maintain the device at its operating temperature and minimize the refrigeration losses, high performance of thermal isolation is essential. The radiation from warm surrounding surfaces and conducting heat leaks through supports and penetrations are the dominant heat loads to the cold mass under vacuum condition. The advanced developments in various cryogenic applications to successfully reduce the heat loads through radiation and conduction are briefly and systematically discussed and evaluated in this review paper. These include: (1) thermal Insulation for different applications (foams, perlites, glass bubbles, aerogel and MLI), (2) sophisticated low-heat-leak support (cryogenic tension straps, trolley bars and posts with dedicated thermal intercepts), and (3) novel cryogenic heat switches.

Effect of mineral additives on structure and properties of concrete for pavements

NASA Astrophysics Data System (ADS)

Sobol, Khrystyna; Markiv, Taras; Hunyak, Oleksii

2017-12-01

Concrete pavements is an attractive alternative to asphalt pavements because of its lower cost and higher durability. Major contribution to sustainable development can be made by partial replacement of cement in concrete pavement with supplementary cementitious materials of different nature and origin. In this paper, the effect of natural zeolite and perlite additives in complex with chemical admixtures on the structure and properties of concrete for pavement was studied. Compressive and flexural strength test was used to study the mechanical behavior of designed concrete under load. Generally, the compressive strength of both control concrete and concrete containing mineral additives levels at the later ages of hardening. The microstructure analysis of concrete with mineral additives of different nature activity showed the formation of additional amount of hydration products such as tobermorite type calcium hydrosilicate which provide self-reinforcement of hardening concrete system.

Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

NASA Technical Reports Server (NTRS)

Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

2007-01-01

The research testing and demonstration of new bulk-fill materials for cryogenic thermal insulation systems was performed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Thermal conductivity testing under actual-use cryogenic conditions is a key to understanding the total system performance encompassing engineering, economics, and materials factors. A number of bulk fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, were tested using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boil-off method were 293 K and 78 K. Tests were performed as a function of cold vacuum pressure from high vacuum to no vacuum conditions. Results are compared with other complementary test methods in the range of 300 K to 20 K. Various testing techniques are shown to be required to obtain a complete understanding of the operating performance of a material and to provide data for answers to design engineering questions.

Biofiltration of waste gases containing a mixture of formaldehyde and methanol.

PubMed

Prado, Oscar J; Veiga, María C; Kennes, Christian

2004-08-01

Several biofilters and biotrickling filters were used for the treatment of a mixture of formaldehyde and methanol; and their efficiencies were compared. Results obtained with three different inert filter bed materials (lava rock, perlite, activated carbon) suggested that the packing material had only little influence on the performance. The best results were obtained in a biotrickling filter packed with lava rock and fed a nutrient solution that was renewed weekly. A maximum formaldehyde elimination capacity of 180 g m(-3) h(-1) was reached, while the methanol elimination capacity rose occasionally to more than 600 g m(-3) h(-1). Formaldehyde degradation was affected by the inlet methanol concentration. Several combinations of load vs empty bed residence time (EBRTs of 71.9, 46.5, 30.0, 20.7 s) were studied, reaching a formaldehyde elimination capacity of 112 g m(-3) h(-1) with about 80% removal efficiency at the lowest EBRT (20.7 s).

Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

1988-01-01

The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

Vibration considerations for cryogenic tanks using glass bubbles insulation

NASA Astrophysics Data System (ADS)

Werlink, Rudy John; Fesmire, James; Sass, Jared P.

2012-06-01

The use of glass bubbles as an efficient and practical thermal insulation system hasbeen previously demonstrated in cryogenic storage tanks. One such example is a spherical,vacuum-jacketed liquid hydrogen vessel of 218,000 liter capacity where the boiloff rate hasbeen reduced by approximately 50 percent. Further applications may include non-stationarytanks such as mobile tankers and tanks with extreme duty cycles or exposed to significantvibration environments. Space rocket launch events and mobile tanker life cycles representtwo harsh cases of mechanical vibration exposure. A number of bulk fill insulationmaterials including glass bubbles, perlite powders, and aerogel granules were tested forvibration effects and mechanical behavior using a custom design holding fixture subjectedto random vibration on an Electrodynamic Shaker. The settling effects for mixtures ofinsulation materials were also investigated. The vibration test results and granular particleanalysis are presented with considerations and implications for future cryogenic tankapplications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whelan, J.A.

During the summer of 1975, the Department of Geology and Geophysics drilled nine drill thermal gradient/heat flow holes. Total footage drilled was 2125 feet. Seven holes were drilled with a Mayhew 1000 drill using various combinations of down the hole hammer drilling, rotary drilling, and NX diamond core drilling. Three of these were heat flow holes--one in the Mineral Range, one in the Tushar Range near Beaver, Utah, and one near Monroe, Utah. Two were alteration study holes in the Roosevelt KGRA and two were temperature gradient holes, in alluvium in the Roosevelt KGRA. The average depth of the holesmore » drilled with the Mayhew 1000 drill was 247 feet. Holes ranged from 135 feet to 492 feet. Cost per foot averaged $18.53. Two holes were core drilled with a Joy 12, BX-size drill. One was to 75 feet, in perlite. This hole was abandoned. The other was to 323 feet in granite.« less

Origin of hydrous alkali feldspar-silica intergrowth in spherulites from intra-plate A2-type rhyolites at the Jabal Shama, Saudi Arabia

NASA Astrophysics Data System (ADS)

Surour, Adel A.; El-Nisr, Said A.; Bakhsh, Rami A.

2016-03-01

Miocene rhyolites (19.2 ± 0.9 Ma) at the Jabal Shama in western Saudi Arabia represent an example of rift-related silicic volcanism that took place during the formation of the Red Sea. They mostly consist of tuffaceous varieties with distinct flow banding, and pea-sized spherulites, obsidian and perlitized rhyolite tuffs. Although they have the geochemical signature of A2-type rhyolites, these silicic rocks are not typically alkaline but alkali-calcic to calc-alkaline. They developed in a within-plate regime and possibly derived from a recycled mafic subducted slab in depleted sub-continental mantle beneath the western Arabian plate. The Jabal Shama rhyolites are younger in age than their Miocene counterparts in Yemen and Ethiopia. The Jabal Shama spherulites consist of hydrous alkali feldspar-silica radial intergrowths with an occasional brown glass nucleus. Carbonate- and glass-free spherulites give up to 4.45 wt% L.O.I. The hydrous nature of these silicates and the absence of magnetite in the spherulites is a strong indication of oxidizing conditions. The spherulites contain hydrous feldspars with up to ∼6 wt% H2O, and they develop by diffusion and devitrification of glass in the rhyolite tuff at ∼800 °C. Owing to higher undercooling due to supersaturation, the radial hydrous phases within spherulites might grow faster and led to coagulation. The polygonal contacts between spherulites and the ∼120° dihedral angle suggest solid-state modification and recrystallization as the process of devitrification proceeds as low as ∼300 °C. The sum of FeO + MgO is positively correlated with total alkalies along with magnetite oxidation in the matrix to Fe-oxyhydroxides, and to the incorporation of OH- into silicates within the spehrulites themselves. Structural H2O in glass of the Jabal Shama perlite (obsidian) is considerable (∼9-12 wt%) with 3.72-5.6 wt% L.O.I. of the whole-rock. The presence of deleterious silica impurities would lower the ore grade due to poor expansion. Zeolitization of the rhyolite tuff was limited or incomplete in comparison with that of Pliocene-Pleistocene rift-related mafic volcanics in the western Arabian plate.

Development of materials for the removal of metal ions from radioactive and non-radioactive waste streams

NASA Astrophysics Data System (ADS)

Hasan, Md. Shameem

Nuclear wastes that were generated during cold-war era from various nuclear weapon programs are presently stored in hundreds of tanks across the United States. The composition of these wastes is rather complex containing both radionuclides and heavy metals, such as 137Cs, 90Sr, Al, Pb, Cr, and Cd. In this study, chitosan based biosorbents were prepared to adsorb some of these metal ions. Chitosan is a partially acetylated glucosamine biopolymer encountered in the cell walls of fungi. In its natural form this material is soft and has a tendency to agglomerate or form gels. Various methods were used to modify chitosan to avoid these problems. Chitosan is generally available commercially in the form of flakes. For use in an adsorption system, chitosan was made in the form of beads to reduce the pressure drop in an adsorption column. In this research, spherical beads were prepared by mixing chitosan with perlite and then by dropwise addition of the slurry mixture into a NaOH precipitation bath. Beads were characterized using Fourier Transform InfraRed Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy dispersive spectroscopy (EDS), Tunneling Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Thermogravimetric Analysis (TGA). The SEM, EDS, and TEM data indicated that the beads were porous in nature. The TGA data showed that bead contained about 32% chitosan. The surface area, pore volume, and porosity of the beads were determined from the BET surface area that was measured using N2 as adsorbate at 77K. Adsorption and desorption of Cr(VI), Cr(III), Cd(II), U(VI), Cu(II), from aqueous solutions of these metal ions were studied to evaluate the adsorption capacities of the beads for these metals ions. Equilibrium adsorption data of these metals on the beads were found to correlate well with the Langmuir isotherm equation. Chitosan coated perlite beads had negligible adsorption capacity for Sr(II) and Cs(I). It was found that Fullers earth had very good capacity for these two metals. However, the mechanical strength of Fullers earth granules available commercially was not sufficient for use in a column. In this study chitosan was used as a binder to make Fullers earth beads and were used for adsorption of Cs(I) and Sr(II). (Abstract shortened by UMI.)

Effect of genetic and phenotypic factors on the composition of commercial marmande type tomatoes studied through HRMAS NMR spectroscopy.

PubMed

Iglesias, María José; García López, Jesús; Collados Luján, Juan Fernando; López Ortiz, Fernando; Bojórquez Pereznieto, Humberto; Toresano, Fernando; Camacho, Francisco

2014-01-01

The effects of genetic, technological and environmental factors on the chemical composition of four marmande type tomato varieties have been investigated. The study is based on the analysis of (1)H HRMAS NMR spectra of tomato purée using a combination of partial least squares (PLS) and assigned signal analysis (ASA). In agreement with genetic, morphological and taste characteristics of the tomatoes studied, the analysis of the NMR data allows two groups of samples to be differentiated. The type of culture and climatic conditions can reduce the compositional differences. The extension of the compositional changes produced by climatic conditions is variety-depend. Neither grafting nor perlite affect significantly the relative content of primary metabolites. This was not the case for tomatoes grown using the pure hydroponic production system based on the recirculation of nutrient solution, New Growing System NGS®, which seems to be an effective agricultural approach to improve tomato quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Can green roof act as a sink for contaminants? A methodological study to evaluate runoff quality from green roofs.

PubMed

Vijayaraghavan, K; Joshi, Umid Man

2014-11-01

The present study examines whether green roofs act as a sink or source of contaminants based on various physico-chemical parameters (pH, conductivity and total dissolved solids) and metals (Na, K, Ca, Mg, Al, Fe, Cr, Cu, Ni, Zn, Cd and Pb). The performance of green roof substrate prepared using perlite, vermiculite, sand, crushed brick, and coco-peat, was compared with local garden soil based on improvement of runoff quality. Portulaca grandiflora was used as green roof vegetation. Four different green roof configurations, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). In general, the vegetated green roof assemblies generated better-quality runoff with less conductivity and total metal ion concentration compared to un-vegetated assemblies. Of the different green roof configurations examined, P. grandiflora planted on green roof substrate acted as sink for various metals and showed the potential to generate better runoff. Copyright © 2014 Elsevier Ltd. All rights reserved.

Removal of copper from aqueous solution using perlite

NASA Astrophysics Data System (ADS)

Tanaydin, Mehmet Kayra; Tanaydin, Zümra Bakici; Ince, Muharrem; Demırkiran, Nizamettin

2017-04-01

The wastewaters containing organic and inorganic pollutants after many industrial processes such as metal plating, mining, textile, alloy, battery and industrial chemicals, are often discharged to environment. Heavy metals among these pollutants have highly stable, toxic, non-degradable and carcinogenic characters. They affect not only ecological system, but also human health and many life forms. Therefore, these contaminants should be eliminated or reduced to allowable levels before releasing to environment. Most of heavy metals have toxic character even at low concentrations of about 0.1-0.3 ppm. Treatment technologies such as filtration, ion exchange, precipitation, electrodeposition, reverse osmosis, sedimentation, and adsorption have been applied for removal of heavy metals from aqueous solutions. Adsorption is one of the most common and widely applied methods to eliminate the metal ions from waste solutions because of its simplicity and cost effectiveness. Activated carbon, clay minerals, ion exchange resins and various agricultural residues can be used as adsorbent materials in this process [1-3].

Influence of reactive fillers on concrete corrosion resistance

NASA Astrophysics Data System (ADS)

Rakhimbayev, Sh M.; Tolypina, N. M.; Khakhaleva, E. N.

2018-03-01

Contact surfaces represent the weakest link in a conglomerate structure of materials. They ensure the diffusion of aggressive agents inside the material. To reduce the conductivity of contact surfaces it is advisable to use reactive fillers, which interact with cement matrix via certain mechanisms, which in turn, reduces the permeability of the contact layer and fosters durability of products. The interaction of reactive fillers with calcium hydroxide of a concrete liquid phase in a contact area leads to the formation of hydrated calcium silicates of a tobermorite group. Such compounds, being settled in pores and capillaries of a product, colmatage and clog them to some extent thus leading to diffusion delay (inhibition) with regard to aggressive components of external media inside porous material, which in turn inhibits the corrosion rate. The authors studied and compared the corrosion of cement concrete with a standard filler (quartz sand) and a reactive filler (perlite and urtit). The experiments confirmed the positive influence of active fillers on concrete corrosion resistance.

A New Thermal Treatment Process of Low Value Volcanic Glass towards the Production of Expanded Material and its Use on CNTs’ Synthesis as Substrate Material

NASA Astrophysics Data System (ADS)

Angelopoulos, Panagiotis M.; Samouhos, Michail; Taxiarchou, Maria; Tsakiridis, P.; Haggman, John; Joyce, Paul

2018-05-01

Pitchstone is a naturally occurring volcanic glass that contains considerable amount of chemically bound water (> 6 % wt). Due to its high water content, its direct thermal processing in conventional expansion furnaces towards the production of lightweight material, similar to expanded perlite, is practically impossible. In the current research paper a sophisticated 2 stage process is presented that consists of a partial dehydration and an expansion stage towards the production of high quality expanded material. After proper treatment, low-value volcanic glass is transformed to frothy, lightweight material of closed external surface and apparent density of 52 kg·m-3 that can be used in various branches of the industry. The material produced is used as substrate for the development of multiwall CNTs through CVD method. Dense multiwall CNT clusters were identified on expanded pitchstone surface, thus rendering the material suitable for such application.

Microbial populations and activities in the rhizoplane of rock-weathering desert plants. II. Growth promotion of cactus seedlings.

PubMed

Puente, M E; Li, C Y; Bashan, Y

2004-09-01

Four bacterial species isolated from the rhizoplane of cacti growing in bare lava rocks were assessed for growth promotion of giant cardon cactus seedlings (Pachycereus pringlei). These bacteria fixed N(2), dissolved P, weathered extrusive igneous rock, marble, and limestone, and significantly mobilized useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn in rock minerals. Cardon cactus seeds inoculated with these bacteria were able to sprout and grow normally without added nutrients for at least 12 months in pulverized extrusive igneous rock (ancient lava flows) mixed with perlite. Cacti that were not inoculated grew less vigorously and some died. The amount of useful minerals (P, K, Fe, Mg) for plant growth extracted from the pulverized lava, measured after cultivation of inoculated plants, was significant. This study shows that rhizoplane bacteria isolated from rock-growing cacti promote growth of a cactus species, and can help supply essential minerals for a prolonged period of time.

Micropropagation of chokeberry by in vitro axillary shoot proliferation.

PubMed

Litwińczuk, Wojciech

2013-01-01

The black chokeberry-aronia (Aronia melanocarpa Elliot) is a shrub native to North America although nowadays well known in Eastern Europe. The fruits are regarded as the richest source of antioxidant phytonutrients among fruit crops and vegetables. Chokeberries can be easily propagated by seeds but this method is not recommended. Micropropagation is far more efficient than other conventional cloning methods like layering or softwood cuttings. Aronia clones are propagated in vitro through four- or three-stage method based on subculturing of shoot explants. The double diluted MS or full strength MS medium with elevated 50% Ca(2+) and Mg(2+) content are used in the initiation and proliferation chokeberry in vitro cultures, respectively. They are supplemented with 0.5-1.0 mg LBA, and 0.05 mg LIBA. The double-phase medium is recommended in the last passage before shoot rooting. The regenerated shoots could be rooted both in vitro on double diluted MS with 0.05 mg L(-1) IBA or in vivo in peat and perlite substrate and subsequently grown in the greenhouse.

In vitro propagation of jojoba.

PubMed

Llorente, Berta E; Apóstolo, Nancy M

2013-01-01

Jojoba (Simmondsia chinensis (Link) Schn.) is a nontraditional crop in arid and semi-arid areas. Vegetative propagation can be achieved by layering, grafting, or rooting semi-hardwood cuttings, but the highest number of possible propagules is limited by the size of the plants and time of the year. Micropropagation is highly recommended strategy for obtaining jojoba elite clones. For culture initiation, single-node explants are cultivated on Murashige and Skoog medium (MS) supplemented with Gamborg's vitamins (B5), 11.1 μM BA (N(6)-benzyl-adenine), 0.5 μM IBA (indole-3-butyric acid), and 1.4 μM GA(3) (gibberellic acid). Internodal and apical cuttings proliferate on MS medium containing B5 vitamins and 4.4 μM BA. Rooting is achieved on MS medium (half strength mineral salt) amended with B5 vitamins and 14.7 μM IBA during 7 days and transferred to develop in auxin-free rooting medium. Plantlets are acclimatized using a graduated humidity regime on soil: peat: perlite (5:1:1) substrate. This micropagation protocol produces large numbers of uniform plants from selected genotypes of jojoba.

Cost-Efficient Storage of Cryogens

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Sass, J. P.; Nagy, Z.; Sojoumer, S. J.; Morris, D. L.; Augustynowicz, S. D.

2007-01-01

NASA's cryogenic infrastructure that supports launch vehicle operations and propulsion testing is reaching an age where major refurbishment will soon be required. Key elements of this infrastructure are the large double-walled cryogenic storage tanks used for both space vehicle launch operations and rocket propulsion testing at the various NASA field centers. Perlite powder has historically been the insulation material of choice for these large storage tank applications. New bulk-fill insulation materials, including glass bubbles and aerogel beads, have been shown to provide improved thermal and mechanical performance. A research testing program was conducted to investigate the thermal performance benefits as well as to identify operational considerations and associated risks associated with the application of these new materials in large cryogenic storage tanks. The program was divided into three main areas: material testing (thermal conductivity and physical characterization), tank demonstration testing (liquid nitrogen and liquid hydrogen), and system studies (thermal modeling, economic analysis, and insulation changeout). The results of this research work show that more energy-efficient insulation solutions are possible for large-scale cryogenic storage tanks worldwide and summarize the operational requirements that should be considered for these applications.

Cyprodinil retention on mixtures of soil and solid wastes from wineries. Effects of waste dose and ageing.

PubMed

Rodríguez-Salgado, Isabel; Paradelo-Pérez, Marcos; Pérez-Rodríguez, Paula; Cutillas-Barreiro, Laura; Fernández-Calviño, David; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

2014-01-01

In spite of its wide-world economic relevance, wine production generates a huge amount of waste that threatens the environment. A batch experiment was designed to assess the effect of the amendment of an agricultural soil with two winery wastes (perlite and bentonite wastes) in the immobilization of cyprodinil. Waste addition (0, 10, 20, 40, and 80 Mg ha(-1)) and different times of incubation of soil-waste mixtures (1, 30, and 120 days) were tested. The addition of wastes improved the soil's ability to immobilize cyprodinil, which was significantly correlated to total C content in soil-waste mixtures. Longer incubation times decreased the cyprodinil sorption possibly due to the mineralization of organic matter but also as a consequence of the high pH values reached after bentonite waste addition (up to 10.0). Cyprodinil desorption increased as the amount of waste added to soil, and the incubation time increased. The use of these winery wastes contributes to a more sustainable agriculture preventing fungicide mobilization to groundwater.

Efficiency of a NPK fertilizer with adhered zinc lignosulfonate as a zinc source for maize (Zea mays L.).

PubMed

Martín-Ortiz, Diego; Hernández-Apaolaza, Lourdes; Gárate, Agustín

2009-10-14

The aim of this work was to evaluate the efficiency of a NPK fertilizer (8:15:15) with a Zn lignosulfonate (ZnLS) adhered as Zn source for maize plants. This product was compared in three experimental designs with the same NPK fertilizer with ZnSO(4) adhered and with no Zn adhered. The first and the second assays were carried out in a growth chamber by using perlite and a calcareous soil as substrate and the third experiment was raised in two calcareous fields. In general, growth chamber experiments showed that plants treated with NPK + ZnLS presented the highest dry weight and Zn concentrations in shoots. Also at field experiments, the Zn concentration in shoots was significantly high in plants treated with NPK + ZnLS. The grain harvested showed that this treatment gave the highest values in one location, but in the other no significant differences were observed. Although further research is required, we can conclude that NPK + ZnLS product could be a suitable source of Zn for maize crops.

Alterations in Aspergillus brasiliensis (niger) ATCC 9642 membranes associated to metabolism modifications during application of low-intensity electric current.

PubMed

Velasco-Alvarez, Nancy; Gutiérrez-Rojas, Mariano; González, Ignacio

2017-12-01

The effects of electric current on membranes associated with metabolism modifications in Aspergillus brasiliensis (niger) ATCC 9642 were studied. A 450-mL electrochemical cell with titanium ruthenium-oxide coated electrodes and packed with 15g of perlite, as inert support, was inoculated with A. brasiliensis spores and incubated in a solid inert-substrate culture (12 d; 30°C). Then, 4.5days after starting the culture, a current of 0.42mAcm -2 was applied for 24h. The application of low-intensity electric current increased the molecular oxygen consumption rate in the mitochondrial respiratory chain, resulting in high concentrations of reactive oxygen species, promoting high lipoperoxidation levels, according to measured malondialdehyde, and consequent alterations in membrane permeability explained the high n-hexadecane (HXD) degradation rates observed here (4.7-fold higher than cultures without current). Finally, cell differentiation and spore production were strongly stimulated. The study contributes to the understanding of the effect of current on the cell membrane and its association with HXD metabolism. Copyright © 2017. Published by Elsevier B.V.

Bacterial community analysis of Tatsoi cultivated by hydroponics.

PubMed

Koo, Ok K; Kim, Hun; Kim, Hyun J; Baker, Christopher A; Ricke, Steven C

2016-07-02

Tatsoi (Brassica narinosa) is a popular Asian salad green that is mostly consumed as a source of fresh produce. The purpose of this study was to assess the microbial diversity of Tatsoi cultivated in a hydroponic system and of its ecosystem. Tatsoi leaves, nutrient solution, and perlite/earth samples from a trickle feed system (TFS) and an ebb-and-flow system (EFS) were collected and their microbial communities were analyzed by pyrosequencing analysis. The results showed that most bacteria in the leaves from the TFS contained genus Sporosarcina (99.6%), while Rhizobium (60.4%) was dominant in the leaves from the EFS. Genus Paucibacter (18.21%) and Pelomonas (12.37%) were the most abundant microbiota in the nutrient solution samples of the TFS. In the EFS, the nutrient solution samples contained mostly genus Rhodococcus and Acinetobacter. Potential microbial transfer between the leaves and the ecosystem was observed in the EFS, while samples in the TFS were found to share only one species between the leaves, nutrient solution, and earth. Together, these results show that the bacterial populations in Tatsoi and in its ecosystem are highly diverse based on the cultivation system.

Adsorption-synergic biodegradation of diesel oil in synthetic seawater by acclimated strains immobilized on multifunctional materials.

PubMed

Wang, Xin; Wang, Xuejiang; Liu, Mian; Bu, Yunjie; Zhang, Jing; Chen, Jie; Zhao, Jianfu

2015-03-15

Using enrichment culture technique, three isolates marked as ODB-1, ODB-2 and ODB-3, were selected from oil contaminated seawater. 16S rDNA gene sequencing indicated that ODB-1 affiliated with Pseudomonas sp. while ODB-2 and ODB-3 affiliated with Brevundimonas sp. Subsequently, the bacterial cells were immobilized on the surface of expanded graphite (EG), expanded perlite (EP) and bamboo charcoal (BC). Among the three isolates, ODB-1 showed a strong binding to the bio-carriers through extracellular polysaccharides, while ODB-2 and ODB-3 made the adhesion to bio-carrier through direct physical adsorption. The immobilized bacteria exhibited good salinity tolerance compared with the planktonic bacteria. Their total diesel oil removal rates were more than 85% after 6 days' incubation. Adsorption-biodegradation process played an important role in the oil-pollution remediation. EG-bacteria system was treated as a promising remediation method, which achieved nearly 100% removal of diesel oil. Thereinto, over 83% removal of diesel oil owed to biodegradation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Numerical Modeling of Propellant Boiloff in Cryogenic Storage Tank

NASA Technical Reports Server (NTRS)

Majumdar, A. K.; Steadman, T. E.; Maroney, J. L.

2007-01-01

This Technical Memorandum (TM) describes the thermal modeling effort undertaken at Marshall Space Flight Center to support the Cryogenic Test Laboratory at Kennedy Space Center (KSC) for a study of insulation materials for cryogenic tanks in order to reduce propellant boiloff during long-term storage. The Generalized Fluid System Simulation program has been used to model boiloff in 1,000-L demonstration tanks built for testing the thermal performance of glass bubbles and perlite insulation. Numerical predictions of boiloff rate and ullage temperature have been compared with the measured data from the testing of demonstration tanks. A satisfactory comparison between measured and predicted data has been observed for both liquid nitrogen and hydrogen tests. Based on the experience gained with the modeling of the demonstration tanks, a numerical model of the liquid hydrogen storage tank at launch complex 39 at KSC was built. The predicted boiloff rate of hydrogen has been found to be in good agreement with observed field data. This TM describes three different models that have been developed during this period of study (March 2005 to June 2006), comparisons with test data, and results of parametric studies.

Trace Metals in Urban Stormwater Runoff and their Management

NASA Astrophysics Data System (ADS)

Li, T.; Hall, K.; Li, L. Y.; Schreier, H.

2009-04-01

In past decades, due to the rapid urbanization, land development has replaced forests, fields and meadows with impervious surfaces such as roofs, parking lots and roads, significantly affecting watershed quality and having an impact on aquatic systems. In this study, non-point source pollution from a diesel bus loop was assessed for the extent of trace metal contamination of Cu, Mn, Fe, and Zn in the storm water runoff. The study was carried out at the University of British Columbia (UBC) in the Greater Vancouver Regional District (GVRD) of British Columbia, Canada. Fifteen storm events were monitored at 3 sites from the diesel bus loop to determine spatial and temporal variations of dissolved and total metal concentrations in the storm water runoff. The dissolved metal concentrations were compared with the provincial government discharge criteria and the bus loop storm water quality was also compared with previous studies conducted across the GVRD urban area. To prevent storm water with hazardous levels of contaminants from being discharged into the urban drainage system, a storm water catch basin filter was installed and evaluated for its efficiency of contaminants removal. The perlite filter media adsorption capacities for the trace metals, oil and grease were studied for better maintenance of the catch basin filter. Dissolved copper exceeded the discharge criteria limit in 2 out of 15 cases, whereas dissolved zinc exceeded the criteria in 4 out of 15 cases, and dissolved manganese was below the criteria in all of the events sampled. Dissolved Cu and Zn accounted for 36 and 45% of the total concentration, whereas Mn and Fe only accounted for 20 and 4% of their total concentration, respectively. Since they are more mobile and have higher bioaccumulation potentials, Zn and Cu are considered to be more hazardous to the aquatic environment than Fe and Mn. With high imperviousness (100%) and intensive traffic at the UBC diesel bus loop, trace metal concentrations were 3, 0.7, 9, and 3.2 times higher than the GVRD urban area limits for Cu, Mn, Fe, and Zn, respectively. The filter showed high and stable capture efficiencies in total metals (Cu 62%, Mn 75%, Fe 83%, Zn 62%), dissolved metals (Cu 39%, Mn 37%, Fe 47%, Zn 32%), turbidity (72%), and suspended solids (74%) removal during the first month of operation. After that, there was gradual degradation. The catch basin filter performance improved significantly for the suspended solids and total metal removal after cleaning. However, the perlite filter medium showed poor performance for dissolved metal removal in the second study period. Based on the findings, a catch basin filter is effective in storm water management to control suspended solids loading from storm water runoff.

Vertical farming increases lettuce yield per unit area compared to conventional horizontal hydroponics.

PubMed

Touliatos, Dionysios; Dodd, Ian C; McAinsh, Martin

2016-08-01

Vertical farming systems (VFS) have been proposed as an engineering solution to increase productivity per unit area of cultivated land by extending crop production into the vertical dimension. To test whether this approach presents a viable alternative to horizontal crop production systems, a VFS (where plants were grown in upright cylindrical columns) was compared against a conventional horizontal hydroponic system (HHS) using lettuce ( Lactuca sativa L . cv. "Little Gem") as a model crop. Both systems had similar root zone volume and planting density. Half-strength Hoagland's solution was applied to plants grown in perlite in an indoor controlled environment room, with metal halide lamps providing artificial lighting. Light distribution (photosynthetic photon flux density, PPFD) and yield (shoot fresh weight) within each system were assessed. Although PPFD and shoot fresh weight decreased significantly in the VFS from top to base, the VFS produced more crop per unit of growing floor area when compared with the HHS. Our results clearly demonstrate that VFS presents an attractive alternative to horizontal hydroponic growth systems and suggest that further increases in yield could be achieved by incorporating artificial lighting in the VFS.

Fluid mechanical scaling of impact craters in unconsolidated granular materials

NASA Astrophysics Data System (ADS)

Miranda, Colin S.; Dowling, David R.

2015-11-01

A single scaling law is proposed for the diameter of simple low- and high-speed impact craters in unconsolidated granular materials where spall is not apparent. The scaling law is based on the assumption that gravity- and shock-wave effects set crater size, and is formulated in terms of a dimensionless crater diameter, and an empirical combination of Froude and Mach numbers. The scaling law involves the kinetic energy and speed of the impactor, the acceleration of gravity, and the density and speed of sound in the target material. The size of the impactor enters the formulation but divides out of the final empirical result. The scaling law achieves a 98% correlation with available measurements from drop tests, ballistic tests, missile impacts, and centrifugally-enhanced gravity impacts for a variety of target materials (sand, alluvium, granulated sugar, and expanded perlite). The available measurements cover more than 10 orders of magnitude in impact energy. For subsonic and supersonic impacts, the crater diameter is found to scale with the 1/4- and 1/6-power, respectively, of the impactor kinetic energy with the exponent crossover occurring near a Mach number of unity. The final empirical formula provides insight into how impact energy partitioning depends on Mach number.

Stabilization of pH in solid-matrix hydroponic systems

NASA Technical Reports Server (NTRS)

Frick, J.; Mitchell, C. A.

1993-01-01

2-[N-morpholino]ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome : ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 mM) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite : 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g m-2 day-1) were about double that of the control (8.2 g m-2 day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g m-2 day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mM MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.

Biological removal of gaseous ammonia in biofilters: space travel and earth-based applications

NASA Technical Reports Server (NTRS)

Joshi, J. A.; Hogan, J. A.; Cowan, R. M.; Strom, P. F.; Finstein, M. S.; Janes, H. W. (Principal Investigator)

2000-01-01

Gaseous NH3 removal was studied in laboratory-scale biofilters (14-L reactor volume) containing perlite inoculated with a nitrifying enrichment culture. These biofilters received 6 L/min of airflow with inlet NH3 concentrations of 20 or 50 ppm, and removed more than 99.99% of the NH3 for the period of operation (101, 102 days). Comparison between an active reactor and an autoclaved control indicated that NH3 removal resulted from nitrification directly, as well as from enhanced absorption resulting from acidity produced by nitrification. Spatial distribution studies (20 ppm only) after 8 days of operation showed that nearly 95% of the NH3 could be accounted for in the lower 25% of the biofilter matrix, proximate to the port of entry. Periodic analysis of the biofilter material (20 and 50 ppm) showed accumulation of the nitrification product NO3- early in the operation, but later both NO2- and NO3- accumulated. Additionally, the N-mass balance accountability dropped from near 100% early in the experiments to approximately 95 and 75% for the 20- and 50-ppm biofilters, respectively. A partial contributing factor to this drop in mass balance accountability was the production of NO and N2O, which were detected in the biofilter exhaust.

Biological removal of gaseous ammonia in biofilters: space travel and earth-based applications.

PubMed

Joshi, J A; Hogan, J A; Cowan, R M; Strom, P F; Finstein, M S

2000-09-01

Gaseous NH3 removal was studied in laboratory-scale biofilters (14-L reactor volume) containing perlite inoculated with a nitrifying enrichment culture. These biofilters received 6 L/min of airflow with inlet NH3 concentrations of 20 or 50 ppm, and removed more than 99.99% of the NH3 for the period of operation (101, 102 days). Comparison between an active reactor and an autoclaved control indicated that NH3 removal resulted from nitrification directly, as well as from enhanced absorption resulting from acidity produced by nitrification. Spatial distribution studies (20 ppm only) after 8 days of operation showed that nearly 95% of the NH3 could be accounted for in the lower 25% of the biofilter matrix, proximate to the port of entry. Periodic analysis of the biofilter material (20 and 50 ppm) showed accumulation of the nitrification product NO3- early in the operation, but later both NO2- and NO3- accumulated. Additionally, the N-mass balance accountability dropped from near 100% early in the experiments to approximately 95 and 75% for the 20- and 50-ppm biofilters, respectively. A partial contributing factor to this drop in mass balance accountability was the production of NO and N2O, which were detected in the biofilter exhaust.

Characterization of Xanthophyll Pigments, Photosynthetic Performance, Photon Energy Dissipation, Reactive Oxygen Species Generation and Carbon Isotope Discrimination during Artemisinin-Induced Stress in Arabidopsis thaliana

PubMed Central

Hussain, M. Iftikhar; Reigosa, Manuel J.

2015-01-01

Artemisinin, a potent antimalarial drug, is phytotoxic to many crops and weeds. The effects of artemisinin on stress markers, including fluorescence parameters, photosystem II photochemistry, photon energy dissipation, lipid peroxidation, reactive oxygen species generation and carbon isotope discrimination in Arabidopsis thaliana were studied. Arabidopsis ecotype Columbia (Col-0) seedlings were grown in perlite and watered with 50% Hoagland nutrient solution. Adult plants of Arabidopsis were treated with artemisinin at 0, 40, 80, 160 μM for one week. Artemisinin, in the range 40–160 μM, decreased the fresh biomass, chl a, b and leaf mineral contents. Photosynthetic efficiency, yield and electron transport rate in Arabidopsis were also reduced following exposure to 80 and 160 μM artemisinin. The ΦNPQ and NPQ were less than control. Artemisinin treatment caused an increase in root oxidizability and lipid peroxidation (MDA contents) of Arabidopsis. Calcium and nitrogen contents decreased after 80 and 160 μM artemisinin treatment compared to control. δ13C values were less negative following treatment with artemisinin as compared to the control. Artemisinin also decreased leaf protein contents in Arabidopsis. Taken together, these data suggest that artemisinin inhibits many physiological and biochemical processes in Arabidopsis. PMID:25635811

Effect of chitosan solution on the inhibition of Acidovorax citrulli causing bacterial fruit blotch of watermelon.

PubMed

Li, Bin; Shi, Yu; Shan, Changlin; Zhou, Qing; Ibrahim, Muhammad; Wang, Yanli; Wu, Guoxing; Li, Hongye; Xie, Guanlin; Sun, Guochang

2013-03-30

The production of watermelon in China has been seriously hampered by fruit blotch disease and limited control measures are now applied. Chitosan has been employed to control a variety of plant diseases and is considered to be the most promising biochemical to control this disease. The in vitro antibacterial effect of chitosan and its ability in protection of watermelon seedlings from bacterial fruit blotch were evaluated. Results showed that three types of chitosan, in particular, chitosan A at 0.40 mg mL⁻¹ significantly inhibited the growth of Acidovorax citrulli. The antibacterial activity of chitosan A was affected by chitosan concentration and incubation time. The direct antibacterial activity of chitosan may be attributed to membrane lysis evidenced by transmission electron microscopic observation. The disease index of watermelon seedlings planted in soil and the death rate of seedlings planted in perlite were significantly reduced by chitosan A at 0.40 mg mL⁻¹ compared to the pathogen control. Fresh and dry weight of watermelon seedlings planted in soil was increased by chitosan seed treatment, but not by chitosan leaf spraying. The results indicated that chitosan solution may have a potential in controlling bacterial fruit blotch of watermelon. © 2013 Society of Chemical Industry.

Biodegradation of gas-phase styrene using the fungus Sporothrix variecibatus: impact of pollutant load and transient operation.

PubMed

Rene, Eldon R; Veiga, María C; Kennes, Christian

2010-03-01

Biofiltration of gas-phase styrene was studied using a newly isolated fungus Sporothrix variecibatus, in a perlite biofilter, at inlet concentrations and gas-flow rates ranging from 0.13 to 14 g m(-3) and 0.075 to 0.34 m(3) h(-1), respectively, corresponding to empty bed residence times (EBRT) ranging between 91 and 20s. Styrene loading rates were varied between 50 and 845 g m(-3) h(-1)and a maximum elimination capacity of 336 g m(-3) h(-1) was attained with nearly 65% styrene removal. On the other hand, the critical inlet loads to achieve more than 90% removal were 301, 240 and 92 g m(-3) h(-1) for EBRT of 91, 40, and 20s, respectively. In order to test the stability and shock bearing capacity of the fungal biofilter, short-term tests were conducted by suddenly increasing the gas-phase styrene concentration, while maintaining the gas-flow rate constant. The response, a restoration in the removal performance to previous high values, after subjecting the biofilter to shock loads proves the resilient nature of the attached Sporothrix sp. and its suitability for biofiltration under non-steady state conditions. 2010 Elsevier Ltd. All rights reserved.

Dry deposition of large, airborne particles onto a surrogate surface

NASA Astrophysics Data System (ADS)

Kim, Eugene; Kalman, David; Larson, Timothy

Simultaneous measurements of particle dry deposition flux and airborne number concentration in the open atmosphere were made using three different types of artificially generated particles in the size range 10-100 μm - perlite, diatomaceous earth and glass beads. A combination of gravimetric analysis, automated microscopy and sonic anemometry provided size-resolved estimates of both the inertial and gravitational components of the quasi-laminar layer particle deposition velocity, ( Vd) b, as a function of size. Eddy inertial deposition efficiency ( ηdI) was determined as a function of dimensionless eddy Stokes number (Stk e). In the range 310 μm).

Formulation of stable Bacillus subtilis AH18 against temperature fluctuation with highly heat-resistant endospores and micropore inorganic carriers.

PubMed

Chung, Soohee; Lim, Hyung Mi; Kim, Sang-Dal

2007-08-01

To survive the commercial market and to achieve the desired effect of beneficial organisms, the strains in microbial products must be cost-effectively formulated to remain dormant and hence survive through high and low temperatures of the environment during transportation and storage. Dormancy and stability of Bacillus subtilis AH18 was achieved by producing endospores with enhanced heat resistance and using inorganic carriers. Heat stability assays, at 90 degrees C for 1 h, showed that spores produced under a sublethal temperature of 57 degrees C was 100 times more heat-resistant than the ones produced by food depletion at the growing temperature of 37 degrees C. When these highly heat-resistant endospores were formulated with inorganic carriers of natural and synthetic zeolite or kaolin clay minerals having substantial amount of micropores, the dormancy of the endospores was maintained for 6 months at 15-25 degrees C. Meanwhile, macroporous perlite carriers with average pore diameter larger than 3.7 microm stimulated the germination of the spores and rapid proliferation of the bacteria. These results indicated that a B. subtilis AH18 product that can remain dormant and survive through environmental temperature fluctuation can be formulated by producing heat-stressed endospores and incorporating inorganic carriers with micropores in the formulation step.

Integral parameters for characterizing water, energy, and aeration properties of soilless plant growth media

NASA Astrophysics Data System (ADS)

Chamindu Deepagoda, T. K. K.; Chen Lopez, Jose Choc; Møldrup, Per; de Jonge, Lis Wollesen; Tuller, Markus

2013-10-01

Over the last decade there has been a significant shift in global agricultural practice. Because the rapid increase of human population poses unprecedented challenges to production of an adequate and economically feasible food supply for undernourished populations, soilless greenhouse production systems are regaining increased worldwide attention. The optimal control of water availability and aeration is an essential prerequisite to successfully operate plant growth systems with soilless substrates such as aggregated foamed glass, perlite, rockwool, coconut coir, or mixtures thereof. While there are considerable empirical and theoretical efforts devoted to characterize water retention and aeration substrate properties, a holistic, physically-based approach considering water retention and aeration concurrently is lacking. In this study, the previously developed concept of integral water storage and energy was expanded to dual-porosity substrates and an analog integral oxygen diffusivity parameter was introduced to simultaneously characterize aeration properties of four common soilless greenhouse growth media. Integral parameters were derived for greenhouse crops in general, as well as for tomatoes. The integral approach provided important insights for irrigation management and for potential optimization of substrate properties. Furthermore, an observed relationship between the integral parameters for water availability and oxygen diffusivity can be potentially applied for the design of advanced irrigation and management strategies to ensure stress-free growth conditions, while conserving water resources.

NASA Tech Briefs, April 2010

NASA Technical Reports Server (NTRS)

2010-01-01

Topics covered include: Active and Passive Hybrid Sensor; Quick-Response Thermal Actuator for Use as a Heat Switch; System for Hydrogen Sensing; Method for Detecting Perlite Compaction in Large Cryogenic Tanks; Using Thin-Film Thermometers as Heaters in Thermal Control Applications; Directional Spherical Cherenkov Detector; AlGaN Ultraviolet Detectors for Dual-Band UV Detection; K-Band Traveling-Wave Tube Amplifier; Simplified Load-Following Control for a Fuel Cell System; Modified Phase-meter for a Heterodyne Laser Interferometer; Loosely Coupled GPS-Aided Inertial Navigation System for Range Safety; Sideband-Separating, Millimeter-Wave Heterodyne Receiver; Coaxial Propellant Injectors With Faceplate Annulus Control; Adaptable Diffraction Gratings With Wavefront Transformation; Optimizing a Laser Process for Making Carbon Nanotubes; Thermogravimetric Analysis of Single-Wall Carbon Nanotubes; Robotic Arm Comprising Two Bending Segments; Magnetostrictive Brake; Low-Friction, Low-Profile, High-Moment Two-Axis Joint; Foil Gas Thrust Bearings for High-Speed Turbomachinery; Miniature Multi-Axis Mechanism for Hand Controllers; Digitally Enhanced Heterodyne Interferometry; Focusing Light Beams To Improve Atomic-Vapor Optical Buffers; Landmark Detection in Orbital Images Using Salience Histograms; Efficient Bit-to-Symbol Likelihood Mappings; Capacity Maximizing Constellations; Natural-Language Parser for PBEM; Policy Process Editor for P(sup 3)BM Software; A Quality System Database; Trajectory Optimization: OTIS 4; and Computer Software Configuration Item-Specific Flight Software Image Transfer Script Generator.

Biofiltration of methanol vapor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shareefdeen, Z.; Baltzis, B.C.; Oh, Youngsook

1993-03-05

Biofiltration of solvent and fuel vapors may offer a cost-effective way to comply with increasingly strict air emission standards. An important step in the development of this technology is to derive and validate mathematical models of the biofiltration process for predictive and scaleup calculations. For the study of methanol vapor biofiltration, an 8-membered bacterial consortium was obtained from methanol-exposed soil. The bacteria were immobilized on solid support and packed into a 5-cm diameter, 60-cm-high column provided with appropriate flowmeters and sampling ports. The solid support was prepared by mixing two volumes of peat with three volumes of perlite particles. Twomore » series of experiments were performed. In the first, the inlet methanol concentration was kept constant while the superficial air velocity was varied from run to run. In the second series, the air flow rate (velocity) was kept constant while the inlet methanol concentration was varied. The unit proved effective in removing methanol at rates up to 112.8 g h[sup [minus]1] m[sup [minus]3] packing. A mathematical model has been derived and validated. The model described and predicted experimental results closely. Both experimental data and model predictions suggest that the methanol biofiltration process was limited by oxygen diffusion and methanol degradation kinetics.« less

Metabolism of Ibuprofen by Phragmites australis: Uptake and Phytodegradation

PubMed Central

2017-01-01

This study explores ibuprofen (IBP) uptake and transformation in the wetland plant species Phragmites australis and the underlying mechanisms. We grew P. australis in perlite under greenhouse conditions and treated plants with 60 μg/L of IBP. Roots and rhizomes (RR), stems and leaves (SL), and liquid samples were collected during 21 days of exposure. Results show that P. australis can take up, translocate, and degrade IBP. IBP was completely removed from the liquid medium after 21 days with a half-life of 2.1 days. IBP accumulated in RR and was partly translocated to SL. Meanwhile, four intermediates were detected in the plant tissues: hydroxy-IBP, 1,2-dihydroxy-IBP, carboxy-IBP and glucopyranosyloxy-hydroxy-IBP. Cytochrome P450 monooxygenase was involved in the production of the two hydroxy intermediates. We hypothesize that transformation of IBP was first catalyzed by P450, and then by glycosyltransferase, followed by further storage or metabolism in vacuoles or cell walls. No significant phytotoxicity was observed based on relative growth of plants and stress enzyme activities. In conclusion, we demonstrated for the first time that P. australis degrades IBP from water and is therefore a suitable species for application in constructed wetlands to clean wastewater effluents containing IBP and possibly also other micropollutants. PMID:28346781

Dracaena marginata biofilter: design of growth substrate and treatment of stormwater runoff.

PubMed

Vijayaraghavan, K; Praveen, R S

2016-01-01

The purpose of this research was to investigate the efficiency of Dracaena marginata planted biofilters to decontaminate urban runoff. A new biofilter growth substrate was prepared using low-cost and locally available materials such as red soil, fine sand, perlite, vermiculite, coco-peat and Sargassum biomass. The performance of biofilter substrate was compared with local garden soil based on physical and water quality parameters. Preliminary analyses indicated that biofilter substrate exhibited desirable characteristics such as low bulk density (1140 kg/m(3)), high water holding capacity (59.6%), air-filled porosity (7.82%) and hydraulic conductivity (965 mm/h). Four different biofilter assemblies, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). Results from un-spiked artificial rain events suggested that concentrations of most of the chemical components in effluent were highest at the beginning of rain events and thereafter subsided during the subsequent rain events. Biofilter growth substrate showed superior potential over garden soil to retain metal ions such as Al, Fe, Cu, Cr, Ni, Zn, Cd and Pb during metal-spiked rain events. Significant differences were also observed between non-vegetated and vegetated biofilter assemblies in runoff quality, with the latter producing better results.

Novel Application of Glass Fibers Recovered From Waste Printed Circuit Boards as Sound and Thermal Insulation Material

NASA Astrophysics Data System (ADS)

Sun, Zhixing; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

2013-10-01

The aim of this study is to investigate the feasibility of using glass fibers, a recycled material from waste printed circuit boards (WPCB), as sound absorption and thermal insulation material. Glass fibers were obtained through a fluidized-bed recycling process. Acoustic properties of the recovered glass fibers (RGF) were measured and compared with some commercial sound absorbing materials, such as expanded perlite (EP), expanded vermiculite (EV), and commercial glass fiber. Results show that RGF have good sound absorption ability over the whole tested frequency range (100-6400 Hz). The average sound absorption coefficient of RGF is 0.86, which is prior to those of EP (0.81) and EV (0.73). Noise reduction coefficient analysis indicates that the absorption ability of RGF can meet the requirement of II rating for sound absorbing material according to national standard. The thermal insulation results show that RGF has a fair low thermal conductivity (0.046 W/m K), which is comparable to those of some insulation materials (i.e., EV, EP, and rock wool). Besides, an empirical dependence of thermal conductivity on material temperature was determined for RGF. All the results showed that the reuse of RGF for sound and thermal insulation material provided a promising way for recycling WPCB and obtaining high beneficial products.

Long term storage of Pleurotus ostreatus and Trametes versicolor isolates using different cryopreservation techniques and its impact on laccase activity.

PubMed

Eichlerová, Ivana; Homolka, Ladislav; Tomšovský, Michal; Lisá, Ludmila

2015-12-01

The strain Pleurotus ostreatus Florida f6, its 45 basidiospore-derived isolates (both monokaryons and dikaryons prepared in our laboratory), Trametes versicolor strain CCBAS 614 and 22 other T. versicolor isolates obtained from the sporocarps collected in distant localities were successfully preserved for 12 y using perlite and straw cryopreservation protocols. All tested isolates survived a 12-year storage in liquid nitrogen (LN) and their laccase production and Poly B411 decolorization capacity was preserved. Also mycelium extension rate and the types of colony appearance of individual isolates remained unchanged. Different cryopreservation techniques were also tested for the short time (24 h) and the long time (6 m) storage of the culture liquid with extracellular laccase produced by T. versicolor strain CCBAS 614. The results showed that 10 % glycerol was the most suitable cryopreservant. The absence of the cryopreservant did not cause high loss of laccase activity in the samples; the presence of DMSO (5 or 10 %) in LN-stored samples caused mostly a decrease of laccase activity. For the preservation of laccase activity in the liquid culture the storage in the freezer at -80 °C is more convenient than the storage in liquid nitrogen. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.

PubMed

Liapis, Ioannis; Papayianni, Ioanna

2015-01-01

Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of the β-Mg17Al12 Phase Morphology on the Corrosion Properties Of Az91hp Magnesium Alloy

NASA Astrophysics Data System (ADS)

Guo, Lingling; Zhang, Jumei

2017-09-01

The morphology of β-Mg17Al12 phase and corrosion behavior of AZ91HP magnesium alloy after spheroidizing treatment were investigated by optical microcope electrochemical and immersion tests in 3.5% NaCl at 25°C. The results show that the coarse divorced eutectic phase of AZ91HP cast magnesium alloy dissolve into Mg matrix during the isothermal process at 415°C, and the lameller β phase precipitated from magnesium solid solution as perlite-type precipitation during the slowly cooling. Next, the spheroidizing treatment at different temperatures for 20h was carried out, and the lameller β phase were spheroridizing by dissolved themselves. After spheroidizing treatment at 300°C for 20h, many small granular β phase are scattering within the magnesium matrix. The corrosion properties of AZ91HP magnesium alloy in 3.5% NaCl decreased obviously after spheroidizing treatment, the polarization measurement of the alloy can be up to -1.412V from -1.56V of the cast. The β-Mg17Al12 phase act as a corrosion barrier and hinder corrosion propagation, if the second phase is in the form of a spherical morphology.

Impact of weak water deficit on growth, photosynthetic primary processes and storage processes in pine and spruce seedlings.

PubMed

Zlobin, Ilya E; Ivanov, Yury V; Kartashov, Alexander V; Sarvin, Boris A; Stavrianidi, Andrey N; Kreslavski, Vladimir D; Kuznetsov, Vladimir V

2018-05-19

We investigated the influence of 40 days of drought on growth, storage processes and primary photosynthetic processes in 3-month-old Scots pine and Norway spruce seedlings growing in perlite culture. Water stress significantly affected seedling water status, whereas absolute dry biomass growth was not substantially influenced. Water stress induced an increase in non-structural carbohydrate content (sugars, sugar alcohols, starch) in the aboveground part of pine seedlings in contrast to spruce seedlings. Due to the relatively low content of sugars and sugar alcohols in seedling organs, their expected contribution to osmotic potential changes was quite low. In contrast to biomass accumulation and storage, photosynthetic primary processes were substantially influenced by water shortage. In spruce seedlings, PSII was more sensitive to water stress than PSI. In particular, electron transport in PSI was stable under water stress despite the substantial decrease of electron transport in PSII. The increase in thermal energy dissipation due to enhancement of non-photochemical quenching (NPQ) was evident in both species under water stress. Simultaneously, the yields of non-regulated energy dissipation in PSII were decreased in pine seedlings under drought. A relationship between growth, photosynthetic activities and storage processes is analysed under weak water deficit.

Enhanced hexadecane degradation and low biomass production by Aspergillus niger exposed to an electric current in a model system.

PubMed

Velasco-Alvarez, Nancy; González, Ignacio; Damian-Matsumura, Pablo; Gutiérrez-Rojas, Mariano

2011-01-01

The effects of an electric current on growth and hexadecane (HXD) degradation by Aspergillus niger growth were determined. A 450-mL electrochemical cell with titanium ruthenium-oxide coated electrodes and packed with 15 g of perlite (inert biomass support) was inoculated with A. niger (2.0×10(7) spores (g of dry inert support)(-1)) and incubated for 12 days (30 °C; constant ventilation). 4.5 days after starting culture a current of 0.42 mA cm(-2) was applied for 24h. The current reduced (52±11%) growth of the culture as compared to that of a culture not exposed to current. However, HXD degradation was 96±1.4% after 8 days whereas it was 81±1.2% after 12 days in control cultures. Carbon balances of cultures not exposed to current suggested an assimilative metabolism, but a non-assimilative metabolism when the current was applied. This change can be related to an increase in total ATP content. The study contributes to the knowledge on the effects of current on the mycelial growth phase of A. niger, and suggests the possibility of manipulating the metabolism of this organism with electric current. Copyright © 2010 Elsevier Ltd. All rights reserved.

Preparation and thermal properties of mineral-supported polyethylene glycol as form-stable composite phase change materials (CPCMs) used in asphalt pavements.

PubMed

Jin, Jiao; Lin, Feipeng; Liu, Ruohua; Xiao, Ting; Zheng, Jianlong; Qian, Guoping; Liu, Hongfu; Wen, Pihua

2017-12-05

Three kinds of mineral-supported polyethylene glycol (PEG) as form-stable composite phase change materials (CPCMs) were prepared to choose the most suitable CPCMs in asphalt pavements for the problems of asphalt pavements rutting diseases and urban heat islands. The microstructure and chemical structure of CPCMs were characterized by SEM, FT-IR and XRD. Thermal properties of the CPCMs were determined by TG and DSC. The maximum PEG absorption of diatomite (DI), expanded perlite (EP) and expanded vermiculite (EVM) could reach 72%, 67% and 73.6%, respectively. The melting temperatures and latent heat of CPCMs are in the range of 52-55 °C and 100-115 J/g, respectively. The results show that PEG/EP has the best thermal and chemical stability after 100 times of heating-cooling process. Moreover, crystallization fraction results show that PEG/EP has slightly higher latent heats than that of PEG/DI and PEG/EVM. Temperature-adjusting asphalt mixture was prepared by substituting the fine aggregates with PEG/EP CPCMs. The upper surface maximum temperature difference of temperature-adjusting asphalt mixture reaches about 7.0 °C in laboratory, and the surface peak temperature reduces up to 4.3 °C in the field experiment during a typical summer day, indicating a great potential application for regulating pavement temperature field and alleviating the urban heat islands.

Effects of periods of nonuse and fluctuating ammonia concentration on biofilter performance.

PubMed

Chen, Ying-Xu; Yin, Jun; Wang, Kai-Xiong; Fang, Shi

2004-01-01

A systematic study on the transient behavior of odor treatment using biofilters is described. The biofilters were exposed to variations in contaminant loading and periods of nonuse. Two bench-scale biofilters with different filter media were used. Mixtures of compost/perlite (5:1) and dry sludge/granular active carbon (5:1) were used as filter media. Ammonia (NH3), one of the main malodorous gases, was used as the target compound. The response of each biofilter to variations in contaminant mass loading, periodic nonuse, water content, and inlet concentration pulse was studied. The nonuse period comprised of two stages: the "idle phase" when no air was passing through the biofilters, and the "no-contaminant-loading phase" when only humidified air was passing through the biofilters. Concentration spike was applied to study the effects of shock loading on the biofilter performance. Biofilters responded effectively to NH3 concentration variations and shock loading by rapidly recovering to the original removal rates within 6-12h. The results indicated re-acclimation times ranged from several hours to longer than a day. Longer idle phase produced longer re-acclimation periods than periods of no contaminant loading. When the media was dried during the biofiltration process, elimination capacity dropped accordingly for both biofilters. After 24 h of drying, the biofilter experiment could be restarted and run for a few days for recovering.

Performance analysis and experimental study on rainfall water purification with an extensive green roof matrix layer in Shanghai, China.

PubMed

Guo, Jiankang; Zhang, Yanting; Che, Shengquan

2018-02-01

Current research has validated the purification of rainwater by a substrate layer of green roofs to some extent, though the effects of the substrate layer on rainwater purification have not been adequately quantified. The present study set up nine extensive green roof experiment combinations based on the current conditions of precipitation characteristics observed in Shanghai, China. Different rain with pollutants were simulated, and the orthogonal design L9 (33) test was conducted to measure purification performance. The purification influences of the extensive green roof substrate layer were quantitatively analyzed in Shanghai to optimize the thickness, proportion of substrate, and sodium polyacrylate content. The experimental outcomes resulted in ammonium nitrogen (NH 4 + -N), lead (Pb), and zinc (Zn) removal of up to 93.87%, 98.81%, and 94.55% in the artificial rainfall, respectively, and NH 4 + -N, Pb, and Zn event mean concentration (EMC) was depressed to 0.263 mg/L, 0.002 mg/L and 0.018 mg/L, respectively, which were all well below the pollutant concentrations of artificial rainfall. With reference to the rainfall chemical characteristics of Shanghai, a combination of a 200 mm thickness, proportions of 1:1:2 of Loam: Perlite: Cocopeat and 2 g/L sodium polyacrylate content was suggested for the design of an extensive green roof substrate to purify NH 4 + -N, Pb and Zn.

Modeling biofiltration of VOC mixtures under steady-state conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baltzis, B.C.; Wojdyla, S.M.; Zarook, S.M.

1997-06-01

Treatment of air streams contaminated with binary volatile organic compound (VOC) mixtures in classical biofilters under steady-state conditions of operation was described with a general mathematical model. The model accounts for potential kinetic interactions among the pollutants, effects of oxygen availability on biodegradation, and biomass diversification in the filter bed. While the effects of oxygen were always taken into account, two distinct cases were considered for the experimental model validation. The first involves kinetic interactions, but no biomass differentiation, used for describing data from biofiltration of benzene/toluene mixtures. The second case assumes that each pollutant is treated by a differentmore » type of biomass. Each biomass type is assumed to form separate patches of biofilm on the solid packing material, thus kinetic interference does not occur. This model was used for describing biofiltration of ethanol/butanol mixtures. Experiments were performed with classical biofilters packed with mixtures of peat moss and perlite (2:3, volume:volume). The model equations were solved through the use of computer codes based on the fourth-order Runge-Kutta technique for the gas-phase mass balances and the method of orthogonal collocation for the concentration profiles in the biofilms. Good agreement between model predictions and experimental data was found in almost all cases. Oxygen was found to be extremely important in the case of polar VOCs (ethanol/butanol).« less

Design and performance of a trickling air biofilter for chlorobenzene and o-dichlorobenzene vapors.

PubMed Central

Oh, Y S; Bartha, R

1994-01-01

From contaminated industrial sludge, two stable multistrain microbial enrichments (consortia) that were capable of rapidly utilizing chlorobenzene and o-dichlorobenzene, respectively, were obtained. These consortia were characterized as to their species composition, tolerance range, and activity maxima in order to establish and maintain the required operational parameters during their use in biofilters for the removal of chlorobenzene contaminants from air. The consortia were immobilized on a porous perlite support packed into filter columns. Metered airstreams containing the contaminant vapors were partially humidified and passed through these columns. The vapor concentrations prior to and after biofiltration were measured by gas chromatography. Liquid was circulated concurrently with the air, and the device was operated in the trickling air biofilter mode. The experimental arrangement allowed the independent variation of liquid flow, airflow, and solvent vapor concentrations. Bench-scale trickling air biofilters removed monochlorobenzene, o-dichlorobenzene, and their mixtures at rates of up to 300 g of solvent vapor h(-1) m(-3) filter volume. High liquid recirculation rates and automated pH control were critical for stable filtration performance. When the accumulating NaCl was periodically diluted, the trickling air biofilters continued to remove chlorobenzenes for several months with no loss of activity. The demonstrated high performance and stability of the described trickling air biofilters favor their use in industrial-scale air pollution control. PMID:8085815

Production of herbicide-resistant transgenic Panax ginseng through the introduction of the phosphinothricin acetyl transferase gene and successful soil transfer.

PubMed

Choi, Y E; Jeong, J H; In, J K; Yang, D C

2003-02-01

Herbicide-resistant transgenic Panax ginseng plants were produced by introducing the phosphinothricin acetyl transferase (PAT) gene that confers resistance to the herbicide Basta (bialaphos) through Agrobacterium tumefaciens co-cultivation. Embryogenic callus gathered from cotyledon explants of P. ginseng were pre-treated with 0.5 M sucrose or 0.05 M MgSO(4 )before Agrobacterium infection. This pre-treatment process markedly enhanced the transient expression of the beta-glucuronidase (GUS) gene. Embryogenic callus was initially cultured on MS medium supplemented with 400 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 25 mg/l kanamycin and 300 mg/l cefotaxime. Somatic embryos formed on the surfaces of kanamycin-resistant callus. Upon development into the cotyledonary stage, these somatic embryos were transferred to a medium containing 50 mg/l kanamycin and 5 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction and Southern analyses. Transfer of the transgenic ginseng plantlets to soil was successfully accomplished via acclimatization in autoclaved perlite. Not all of the plantlets survived in soil that had not been autoclaved because of fungal infection, particularly in the region between the roots and leaves. Transgenic plants growing in soil were observed to be strongly resistant to Basta application.

Phase composition and fine structure of 0.18C-1Cr-3Ni-1Mo-Fe steel after plasma-electrolytic treatment

NASA Astrophysics Data System (ADS)

Popova, Natalya; Bayatanova, Lyayla; Nikonenko, Elena; Skakov, Mazhyn; Kozlov, Eduard

2017-01-01

The paper presents the transmission electron microscopy (TEM) investigation of 0.18C-1Cr-3Mn-1Mo- Fe steel specimens to study phase transitions and modification of fine structure after plasma-electrolytic treatment (carbonitriding at 850°C during 5 min). TEM investigations involve two points: on the specimen surface and at ˜40 µm distance from it. The experiments show that the structure in the original state is a mixture consisting of ferrite and perlite grains. Carbonitriding results in a considerable modification of the quality and quantity of steel structure. Thus, on the surface, α-phase is represented by lamellar martensite, while at ˜40 µm depth - by massive and lamellar martensite tempered at low and high temperatures. Moreover, on the subsurface of the martensite plates' boundaries retained austenite layers are observed, while inside plates the particles of alloyed cementite, carbonitrides of M23(C,N)6, M2C0.61N0.39, M6,2C3,5N0,3, M(C,N)2, Cr12Fe32Mo7Ni7 types, and β-graphite are present. In the specimen at the depth of ˜40 µm, retained austenite layers are observed on the boundaries of martensite laths and plates, while inside plates only the particles of alloyed cementite and M23(C,N)6 carbonitride are formed.

Microbial communities responsible for the degradation of poly(lactic acid)/poly(3-hydroxybutyrate) blend mulches in soil burial respirometric tests.

PubMed

Jeszeová, Lenka; Puškárová, Andrea; Bučková, Mária; Kraková, Lucia; Grivalský, Tomáš; Danko, Martin; Mosnáčková, Katarína; Chmela, Štefan; Pangallo, Domenico

2018-06-22

The microbial communities responsible for the degradation of poly(lactic acid)/poly(3-hydroxybutyrate) (PLA/PHB) blend foils were investigated in 1 year long laboratory soil burial experiments. Different PLA/PHB foils were tested: (a) PLA/PHB original transparent foil, (b) PLA/PHB carbon black filled foil and (c) PLA/PHB black foil previously exposed for 90 days to sun light. The microbiome diversity of these three types of foil was compared with that identified from soil/perlite sample at the beginning of experiment and that developed on a cellulose mat. Culture-dependent and culture-independent (DGGE-cloning) approaches together with PLA, PHB and PLA/PHB degradation plate assays were employed. The cultivation strategy combined with degradation tests permitted the isolation and evaluation of several PLA/PHB blend degrading microorganisms such as members of the genera Bacillus, Paenibacillus, Streptomyces, Rhodococcus, Saccharothrix, Arthrobacter, Aureobasidium, Mortierella, Absidia, Actinomucor, Bjerkandera, Fusarium, Trichoderma and Penicillium. The DGGE-cloning investigation increased the information about the microbial communities occurring during bioplastic degradation detecting several bacterial and fungal taxa and some of them (members of the orders Anaerolineales, Selenomonadales, Thelephorales and of the genera Pseudogymnoascus and Pseudeurotium) were revealed here for the first time. This survey showed the microbiome colonizing PLA/PHB blend foils and permitted the isolation of several microorganisms able to degrade the tested polymeric blends.

Modification of chemical properties, Cu fractionation and enzymatic activities in an acid vineyard soil amended with winery wastes: A field study.

PubMed

Rodríguez-Salgado, Isabel; Pérez-Rodríguez, Paula; Gómez-Armesto, Antía; Díaz-Raviña, Montserrat; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel; Fernández-Calviño, David

2017-11-01

The effects of adding two winery wastes, perlite waste (PW) and bentonite waste (BW), to an acid vineyard soil were assessed using some chemical and biological soil properties in a field study that lasted 18 months. The addition of PW (up to 81 Mg ha -1 ) had neither significant nor permanent effects on soil characteristics such as the pH, organic matter content or nutrient concentrations, the amounts of copper or zinc, or the electrical conductivity. Moreover, no persistent negative effects were found on the enzymatic activities after PW application. In contrast, soil that was amended with up to 71 Mg BW ha -1 showed increases in its soil pH values, exchangeable potassium and water soluble potassium and phosphorus contents. In addition, it caused significant increases in the electrical conductivity and water-soluble Cu. In addition, the phosphomonoesterase enzymatic activity decreased significantly (up to 28%) in response to the amendment with 71 Mg BW ha -1 . These results showed that adding BW and PW to the soil may be a good agronomic practice for recycling these types of wastes. However, in the case of PW, its use as a soil amendment must be performed with caution to control its possible harmful effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heat Treatment of Thixo-Formed Hypereutectic X210CrW12 Tool Steel

NASA Astrophysics Data System (ADS)

Rogal, Łukasz; Dutkiewicz, Jan

2012-12-01

Steel is a particularly challenging material to semisolid process because of the high temperatures involved and the potential for surface oxidation. Hot-rolled X210CrW12 tool steel was applied as a feedstock for thixoforming. The samples were heated up to 1525 K (1250 °C) to obtain 30 pct of the liquid phase. They were pressed in the semisolid state into a die preheated up to 473 K (200 °C) using a device based on a high-pressure die casting machine. As a result, a series of main bucket tooth thixo-casts for a mining combine was obtained. The microstructure of the thixo-cast consisted of austenite globular grains (average grain size 46 μm) surrounded by a eutectic mixture (ferrite, austenite, and M7C3 carbides). The average hardness of primary austenite grains was 470 HV0.02 and that of eutectic 551 HV0.02. The X-ray analysis confirmed the presence of 11.8 pct α-Fe, 82.4 pct γ-Fe, and 5.8 pct M7C3 carbides in the thixo-cast samples. Thermal and dilatometric effects were registered in the solid state, and the analysis of curves enabled the determination of characteristic temperatures of heat treatment: 503 K, 598 K, 693 K, 798 K, 828 K, 903 K, and 953 K (230 °C, 325 °C, 420 °C, 525 °C, 555 °C, 630 °C, 680 °C). The thixo-casts were annealed at these temperatures for 2 hours. During annealing in the temperature range 503 K to 693 K (230 °C to 420 °C), the hardness of primary globular grains continuously decreased down to 385HV0.02. The X-ray diffraction showed a slight shift of peaks responsible for the tension release. Moreover, after the treatment at 693 K (420 °C), an additional peak from precipitated carbides was observed in the X-ray diffraction. Thin plates of perlite (average hardness 820 HV0.02) with carbide precipitates appeared at the boundaries of globular grains at 798 K (525 °C). They occupied 17 pct of the grain area. Plates of martensite were found in the center of grains, while the retained austenite was observed among them (average hardness of center grains was 512 HV0.02). A nearly complete decomposition of metastable austenite was achieved after tempering at 828 K (555 °C) due to prevailing lamellar pearlite structure starting at grain boundaries and the martensite located in the center of the grains. The X-ray analysis confirmed the presence of 3.4 pct γ-Fe, 84.6 pct α-Fe, and 12 pct M7C3 carbides. The dilatometric analysis showed that the transformation of metastable austenite into martensite took place during cooling from 828 K (555 °C). The additional annealing at 523 K (250 °C) for 2 hours after heat treatment at 828 K (555 °C) caused the precipitation of carbides from the martensite. After tempering at 903 K (630 °C), the thixo-cast microstructure showed globular grains consisting mainly of thick lamellar perlite of the average hardness 555 HV0.02.

The Influence of Corrosion and Cross-Section Diameter on the Mechanical Properties of B500c Steel

NASA Astrophysics Data System (ADS)

Apostolopoulos, Ch. Alk.

2009-03-01

Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical properties of steel rebar. Exposure to chloride, seawater, salt and saltwater and deicing chemical environments influences the concrete-steel bond and weakens it. A considerable strength factor of the two-phase steel B500c (martensitic, ferritic-perlitic) is considered to be the outer martensitic cortex thickness, which varies according to the area of the rebar cross section. In order to evaluate the influence of corrosion and the size of the area on the mechanical properties of B500c steel, an experimental investigation was conducted on B500c ribbed steel rebar of 8, 12, 16, and 18 mm diameter, and which were artificially corroded for 10, 20, 30, 45, 60, 90, and 120 days. The laboratory tests suggest that corrosion duration and rebar cross-sectional area size had a significant impact on the strength and ductility degradation of the specimens. The tensile mechanical properties before and after corrosion indicated progressive variation and drastic drop in their values. The extended salt spray exposure enhanced the damage and created pits and notches, resulting in stress concentration points and progressive reduction of ductility and available energy. Anti-seismic design and codes that ignore the influence of the size of the cross-section area and the level of corrosion and mechanical behavior of reinforcing steel could lead to unpredictable performance during severe ground motion.

[Induction and in vitro culture of hairy roots of Dianthus caryophyllus and its plant regeneration].

PubMed

Shi, Heping; Zhu, Yuanfeng; Wang, Bei; Sun, Jiangbing; Huang, Shengqin

2014-11-01

To use Agrobacterium rhizogenes-induced hairy roots to create new germplasm of Dianthus caryophyllus, we transformed D. caryophyllus with A. rhizogenes by leaf disc for plant regeneration from hairy roots. The white hairy roots could be induced from the basal surface of leaf explants of D. caryophyllus 12 days after inoculation with A. rhizogenes ATCC15834. The percentage of the rooting leaf explants was about 90% 21 days after inoculation. The hairy roots could grow rapidly and autonomously in liquid or solid phytohormone-free MS medium. The transformation was confirmed by PCR amplification of rol gene of Ri plasmid and silica gel thin-layer chromatography of opines from D. caryophyllus hairy roots. Hairy roots could form light green callus after cultured on MS+6-BA 1.0-3.0 mg/L + NAA 0.1-0.2 mg/L for 15 days. The optimum medium for adventitious shoots formation was MS + 6-BA 2.0 mg/L + NAA 0.02 mg/L, where the rate of adventitious shoot induction was 100% after cultured for 6 weeks. The mean number of adventitious shoot per callus was 30-40. The adventitious shoots can form roots when cultured on phytohormone-free 1/2 MS or 1/2 MS +0.5 mg/L NAA for 10 days. When the rooted plantlets transplanted in the substrate mixed with perlite sand and peat (volume ratio of 1:2), the survival rate was above 95%.

Changes in soil properties and in the growth of Lolium multiflorum in an acid soil amended with a solid waste from wineries.

PubMed

Nóvoa-Muñoz, J C; Simal-Gándara, J; Fernández-Calviño, D; López-Periago, E; Arias-Estévez, M

2008-10-01

The agronomic utility of a solid waste, waste perlite (WP), from wine companies was assessed. In this sense, the natural characteristics of the waste were measured, followed by the monitoring of its effects on the chemical properties of acid soils and the growth of Lolium multiflorum. Taking into account that heavy metals associated to the waste (such as Cu, Zn and Mn) could cause problems when used as amendment, the changes in their total levels and in their soil fractionation were also studied, together with their total contents in L. multiflorum. The high content in C (214gkg(-1)), N (25gkg(-1)), P (534mgkg(-1)) and K (106gkg(-1)) of WP turned it into an appropriate amendment to increase soil fertility, solving at the same time its disposal. WP contributed to increase soil pH (in 2 pH units) and cation exchange capacity (CEC increased in 3cmolckg(-1)units), but reduced the potential Cu phytotoxicity due to a change in Cu distribution towards less soluble fractions. The growth of L. multiflorum adequately responds to the treatment with WP at addition rates below 2.5gkg(-1), whereas the imbalance between nutrients can justify the reduction in biomass production at higher WP addition rates. The levels of heavy metals analyzed in L. multiflorum biomass (8-85gkg(-1)) do not seem to cause undesirable effects on its growth.

The measurement of enamel wear of two toothpastes.

PubMed

Joiner, Andrew; Weader, Elizabeth; Cox, Trevor F

2004-01-01

The aim of this study was to compare the enamel abrasivity of a whitening toothpaste with a standard silica toothpaste. Polished human enamel blocks (4 x 4 mm) were indented with a Knoop diamond. The enamel blocks were attached to the posterior buccal surfaces of full dentures and worn by adult volunteers for 24 hours per day. The blocks were brushed ex vivo for 30 seconds, twice per day with the randomly assigned toothpaste (n = 10 per treatment). The products used were either a whitening toothpaste containing Perlite or a standard silica toothpaste. After four, eight and twelve weeks, one block per subject was removed and the geometry of each Knoop indent was re-measured. From the baseline and post-treatment values of indent length, the amount of enamel wear was calculated from the change in the indent depth. The mean enamel wear (sd) for the whitening toothpaste and the standard silica toothpaste after four weeks was 0.20 (0.11) and 0.14 (0.10); after 8 weeks was 0.44 (0.33) and 0.18 (0.17), and after 12 weeks was 0.60 (0.72) and 0.67 (0.77) microns respectively. After four, eight and twelve weeks, the difference in enamel wear between the two toothpastes was not of statistical significance (p > 0.05, 2 sample t-test) at any time point. The whitening toothpaste did not give a statistically significantly greater level of enamel wear as compared to a standard silica toothpaste over a 4-, 8- and 12-weeks period.

Effect of Vermicompost on Nitrate Leaching and Strawberry Growth

NASA Astrophysics Data System (ADS)

Broz, A. P.; Verma, P.; Appel, C.; Stubler, C.; Yost, J.; Hurley, S.

2016-12-01

The use of vermicompost is suggested as a method to reduce nitrogen losses in crop production; however, it is unclear whether and how vermicompost can affect water quality after a significant irrigation or rainfall event. The objectives of this experiment were to: a) determine the concentration of nitrate-nitrogen in drainage water from vermicompost-amended media planted with strawberry in a greenhouse setting and b) determine vegetative biomass of strawberry grown in vermicompost-amended media. Bare-root strawberry plugs were grown in one-gallon plastic pots. The treatments consisted of two media: 1) a peat:perlite soil-less mix and 2) a fine sand soil with three levels of dairy manure vermicompost addition: 0%, 10%, 25% by weight, and a biweekly synthetic fertilizer treatment of 150 mg N-P-K L-1 evaluated in a full factorial randomized block design. Drainage water from each plant was collected for 18 weeks and analyzed for NO3- concentration. High (1000-5000 mg l-1) amounts of NO3- leaching in vermicompost -amended media were observed during the first two weeks of drainage collection relative to non vermicompost-amended media. Plants grown with vermicompost at 25% with synthetic fertilizer had the highest above-ground vegetative biomass (15.3 g) relative to plants with synthetic fertilizer alone (5.3 g). These data suggest vermicompost addition rates of 10% and 25% by weight promote high vegetative biomass in greenhouse strawberry but may facilitate high nitrate leaching, which can negatively affect water quality and environmental health.

Micropropagation of Cyclopia genistoides, an endemic South African plant of economic importance.

PubMed

Kokotkiewicz, Adam; Luczkiewicz, Maria; Hering, Anna; Ochocka, Renata; Gorynski, Krzysztof; Bucinski, Adam; Sowinski, Pawel

2012-01-01

An efficient micropropagation protocol of Cyclopia genistoides (L.) Vent., an indigenous South African shrub of economic importance, was established. In vitro shoot cultures were obtained from shoot tip fragments of sterile seedlings cultured on solid Schenk and Hildebrandt (SH) medium supplemented with 9.84 microM 6-(gamma,gamma-dimethylallylamino)purine (2iP) and 1.0 microM thidiazuron (TDZ). Maximum shoot multiplication rate [(8.2 +/- 1.3) microshoots/explant)] was observed on this medium composition. Prior to rooting, the multiplied shoots were elongated for 60 days (two 30-days passages) on SH medium with one-half sucrose concentration, supplemented with 4.92 microM indole-3-butyric acid (IBA). The rooting of explants was only possible in the case of the elongated shoots. The highest root induction rate (54.8%) was achieved on solid SH medium with one-half sucrose and one-half potassium nitrate and ammonium nitrate concentration, respectively, supplemented with 28.54 microM indole-3-acetic acid (IAA) and 260.25 microM citric acid. The plantlets were acclimatized for 30 days in the glasshouse, with the use of peat/gravel/perlite substrate (1:1:1). The highest acclimatization rate (80%) was obtained for explants rooted with the use of IAA-supplemented medium. The phytochemical profile of the regenerated plants was similar to that of the reference intact plant material. HPLC analyses showed that C. genistoides plantlets obtained by the micropropagation procedure kept the ability to produce xanthones (mangiferin and isomangiferin) and the flavanone hesperidin, characteristic of wild-growing shrubs.

Copper stress-induced changes in leaf soluble proteome of Cu-sensitive and tolerant Agrostis capillaris L. populations.

PubMed

Hego, Elena; Vilain, Sébastien; Barré, Aurélien; Claverol, Stéphane; Dupuy, Jean-William; Lalanne, Céline; Bonneu, Marc; Plomion, Christophe; Mench, Michel

2016-05-01

Changes in leaf soluble proteome were explored in 3-month-old plants of metallicolous (M) and nonmetallicolous (NM) Agrostis capillaris L. populations exposed to increasing Cu concentrations (1-50 μM) to investigate molecular mechanisms underlying plant responses to Cu excess and tolerance of M plants. Plants were cultivated on perlite (CuSO4 spiked-nutrient solution). Soluble proteins, extracted by the trichloroacetic acid/acetone procedure, were separated with 2-DE (linear 4-7 pH gradient). Analysis of CCB-stained gels (PDQuest) reproducibly detected 214 spots, and 64 proteins differentially expressed were identified using LC-MS/MS. In both populations, Cu excess impacted both light-dependent (OEE, cytochrome b6-f complex, and chlorophyll a-b binding protein), and -independent (RuBisCO) photosynthesis reactions, more intensively in NM leaves (ferredoxin-NADP reductase and metalloprotease FTSH2). In both populations, upregulation of isocitrate dehydrogenase and cysteine/methionine synthases respectively suggested increased isocitrate oxidation and enhanced need for S-containing amino-acids, likely for chelation and detoxification. In NM leaves, an increasing need for energetic compounds was indicated by the stimulation of ATPases, glycolysis, pentose phosphate pathway, and Calvin cycle enzymes; impacts on protein metabolism and oxidative stress increase were respectively suggested by the rise of chaperones and redox enzymes. Overexpression of a HSP70 may be pivotal for M Cu tolerance by protecting protein metabolism. All MS data have been deposited in the ProteomeXchange with the dataset identifier PXD001930 (http//proteomecentral.proteomexchange.org/dataset/PXD001930). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inoculation with Azospirillum sp. and Herbaspirillum sp. Bacteria Increases the Tolerance of Maize to Drought Stress.

PubMed

Curá, José Alfredo; Franz, Diego Reinaldo; Filosofía, Julián Ezequiel; Balestrasse, Karina Beatríz; Burgueño, Lautaro Exequiel

2017-07-26

Stress drought is an important abiotic factor that leads to immense losses in crop yields around the world. Strategies are urgently needed to help plants adapt to drought in order to mitigate crop losses. Here we investigated the bioprotective effects of inoculating corn grown under drought conditions with two types of plant growth-promoting rhizobacteria (PGPR), A. brasilense , strain SP-7, and H. seropedicae , strain Z-152. Plants inoculated with the bacteria were grown in a greenhouse with perlite as a substrate. Two hydric conditions were tested: normal well-watered conditions and drought conditions. Compared to control non-inoculated plants, those that were inoculated with PGPR bacteria showed a higher tolerance to the negative effects of water stress in drought conditions, with higher biomass production; higher carbon, nitrogen, and chlorophyll levels; and lower levels of abscisic acid and ethylene, which are plant hormones that affect the stress response. The oxidative stress levels of these plants were similar to those of non-inoculated plants grown in well-watered conditions, showing fewer injuries to the cell membrane. We also noted higher relative water content in the vegetal tissue and better osmoregulation in drought conditions in inoculated plants, as reflected by significantly lower proline content. Finally, we observed lower gene expression of ZmVP14 in the inoculated plants; notably, ZmVP14 is involved in the biosynthesis of abscisic acid. Taken together, these results demonstrate that these bacteria could be used to help plants cope with the negative effects of drought stress conditions.

Thermographic Methods of Detecting Insulation Voids in Large Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Arens, Ellen; Nurge, Mark; Youngquist, Robert; Starr, Stanley

2010-01-01

Four very large (900Kgal) cryogenic liquid hydrogen and oxygen storage tanks at Kennedy Space Center's LC-39 launch pads were constructed in 1965 to support the Apollo/Saturn V Program and continue to support the Space Shuttle Program. These double-walled spherical tanks with powdered insulation in the annular region, have received minimal refurbishment or even inspection over the years. Intrusively inspecting these tanks would mean a significant down time to the program as the cryogenic liquid and the perlite insulation would have to be removed which would be a significant task and long-term schedule disruption. A study of the tanks was performed to determine the extent to which performance and structural information could be revealed without intrusive inspection. Thermal images of the tanks were taken over a variety of environmental conditions to determine the best conditions under which to compare and use thermography as a health monitoring technique as the tanks continue to age. The settling and subsequent compaction of insulation is a serious concern for cryogenic tanks. Comparison of images from the tanks reveals significant variations in the insulation in the annual regions and point to the use of thermography as a way to monitor for insulation migration and possible compaction. These measurements, when combined with mathematical models of historical boil-off data provide key insight to the condition of the vessels. Acceptance testing methods for new tanks, before they are filled with cryogenic commodity (and thereby thermally cycled), are needed and we explore how thermography can be used to accomplish this.

Two-dimensional modeling of water and heat fluxes in green roof substrates

NASA Astrophysics Data System (ADS)

Suarez, F. I.; Sandoval, V. P.

2016-12-01

Due to public concern towards sustainable development, greenhouse gas emissions and energy efficiency, green roofs have become popular in the last years. Green roofs integrate vegetation into infrastructures to reach additional benefits that minimize negative impacts of the urbanization. A properly designed green roof can reduce environmental pollution, noise levels, energetic requirements or surface runoff. The correct performance of green roofs depends on site-specific conditions and on each component of the roof. The substrate and the vegetation layers strongly influence water and heat fluxes on a green roof. The substrate is an artificial media that has an improved performance compared to natural soils as it provides critical resources for vegetation survival: water, nutrients, and a growing media. Hence, it is important to study the effects of substrate properties on green roof performance. The objective of this work is to investigate how the thermal and hydraulic properties affect the behavior of a green roof through numerical modeling. The substrates that were investigated are composed by: crushed bricks and organic soil (S1); peat with perlite (S2); crushed bricks (S3); mineral soil with tree leaves (S4); and a mixture of topsoil and mineral soil (S5). The numerical model utilizes summer-arid meteorological information to evaluate the performance of each substrate. Results show that the area below the water retention curve helps to define the substrate that retains more water. In addition, the non-linearity of the water retention curve can increment the water needed to irrigate the roof. The heat propagation through the roof depends strongly on the hydraulic behavior, meaning that a combination of a substrate with low thermal conductivity and more porosity can reduce the heat fluxes across the roof. Therefore, it can minimize the energy consumed of an air-conditioner system.

Mineral resources of the Turtle Mountains Wilderness Study Area, San Bernardino County, California

USGS Publications Warehouse

Howard, Keith A.; Nielson, Jane E.; Simpson, Robert W.; Hazlett, Richard W.; Alminas, Henry V.; Nakata, John K.; McDonnell, John R.

1988-01-01

At the request of the U.S. Bureau of Land Management, approximately 105,200 acres of the Turtle Mountains Wilderness Study Area (CDCA-307) were evaluated for mineral resources (known) and resource potential (undiscovered). In this report, the area studied is referred to as "the wilderness study area" or simply "the study area"; any reference to the Turtle Mountain Wilderness Study Area refers only to that part of the wilderness study area for which a mineral survey was requested by the U.S. Bureau of Land Management.The wilderness study area is in southeastern San Bernardino County, Calif. Gold, silver, copper, and lead have been mined within and adjacent to the study area. Copper-zinc-silver-gold mineral occurrences are found in the southern part and gold-silver mineral occurrences are found in the northern part of the study area; identified low- to moderate-grade gold-silver resources occur adjacent to the study area along the western boundary. Six areas in the south-central and northwestern parts of the study area have high resource potential, two broad areas have moderate resource potential, and part of the southwest corner has low resource potential for lode gold, silver, and associated copper, lead, zinc, molybdenum, and tungsten. Alluvium locally within one of these areas has moderate resource potential for placer gold and silver, and the entire area has low resource potential for placer gold and silver. There is low resource potential for perlite, ornamental stone (onyx marble and opal), manganese, uranium and thorium, pegmatite minerals, and oil and gas within the study area. Sand and gravel are abundant but are readily available outside the wilderness study area.

Comparison of effectiveness of abrasive and enzymatic action of whitening toothpastes in removal of extrinsic stains - a clinical trial.

PubMed

Patil, P A; Ankola, A V; Hebbal, M I; Patil, A C

2015-02-01

To compare the effectiveness of abrasive component (perlite/calcium carbonate) and enzymatic component (papain and bromelain) of whitening toothpaste in removal of extrinsic stains. This study is a randomized, triple blind and parallel group study in which 90 subjects aged 18-40 years were included. At baseline, stains scores were assessed by Macpherson's modification of Lobene Stain Index and subjects were randomly assigned to two groups with 45 subjects in each. Group 1 used whitening toothpaste with enzymatic action and group 2 with abrasive action. After 1 month, stain scores were assessed for the effectiveness of the two toothpastes and 2 months later to check the stain prevention efficacy. Wilcoxson's test was used to compare between baseline 1 and 2 months stain scores, and Mann-Witney U-test was applied for intragroup comparison. The mean baseline total stain score for the subjects allocated to the enzymatic toothpaste was 37.24 ± 2.11 which reduced to 30.77 ± 2.48 in 1 month, and for the abrasive paste, total stain reduced from 35.08 ± 2.96 to 32.89 ± 1.95. The reductions in total stain scores with both the pastes were significant compared with baseline stain scores (at 1 month Group 1, P = 0.0233 and Group 2, P = 0.0324; at 2 months, Group 1 P = 0.0356). Both the toothpastes proved to be equally good in removal of extrinsic stains; however, the enzymatic paste showed better results as compared to abrasive toothpaste. Whitening toothpaste with abrasive action and enzymatic action are equally effective in removal of extrinsic stains; however, whitening toothpaste with abrasive action needs to be used with caution. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Symbiotic potential and survival of native rhizobia kept on different carriers

PubMed Central

Ruíz-Valdiviezo, Víctor Manuel; Canseco, Lucía María Cristina Ventura; Suárez, Luis Antonio Castillo; Gutiérrez-Miceli, Federico Antonio; Dendooven, Luc; Rincón-Rosales, Reiner

2015-01-01

Native rhizobia are ideal for use as commercial legume inoculants. The characteristics of the carrier used to store the inoculants are important for the survival and symbiotic potential of the rhizobia. The objective of this study was to investigate the effects of peat (PEAT), perlite sugarcane bagasse (PSB), carboxymethyl cellulose plus starch (CMCS), and yeast extract mannitol supplemented with mannitol (YEMM) on the survival, nodulation potential and N2 fixation capacity of the native strains Sinorhizobium mexicanum ITTG R7T and Rhizobium calliandrae LBP2-1T and of the reference strain Rhizobium etli CFN42T. A factorial design (4 × 3) with four repetitions was used to determine the symbiotic potential of the rhizobial strains. The survival of the strains was higher for PEAT (46% for strain LBP2-1T, 167% for strain CFN42T and 219% for strain ITTG R7T) than for the other carriers after 240 days, except for CFN42T kept on CMCS (225%). All the strains kept on the different carriers effectively nodulated common bean, with the lowest number of nodules found (5 nodules) when CFN42T was kept on CMCS and with the highest number of nodules found (28 nodules) when ITTG R7T was kept on PSB. The nitrogenase activity was the highest for ITTG R7T kept on PEAT (4911 μmol C2H4 per fresh weight nodule h−1); however, no activity was found when the strains were kept on YEMM. Thus, the survival and symbiotic potential of the rhizobia depended on the carrier used to store them. PMID:26413054

Identifying the limitations of conventional biofiltration of diffuse methane emissions at long-term operation.

PubMed

Gómez-Cuervo, S; Hernández, J; Omil, F

2016-08-01

There is growing international concern about the increasing levels of greenhouse gases in the atmosphere, particularly CO2 and methane. The emissions of methane derived from human activities are associated with large flows and very low concentrations, such as those emitted from landfills and wastewater treatment plants, among others. The present work was focused on the biological methane degradation at diffuse concentrations (0.2% vv(-1)) in a conventional biofilter using a mixture of compost, perlite and bark chips as carrier. An extensive characterization of the process was carried out at long-term operation (250 days) in a fully monitored pilot plant, achieving stable conditions during the entire period. Operational parameters such as waterings, nitrogen addition and inlet loads and contact time influences were evaluated. Obtained results indicate that empty bed residence times within 4-8 min are crucial to maximize elimination rates. Waterings and the type of nitrogen supplied in the nutrient solution (ammonia or nitrate) have a strong impact on the biofilter performance. The better results compatible with a stable operation were achieved using nitrate, with elimination capacities up to 7.6 ± 1.1 g CH4 m(-3 )h(-1). The operation at low inlet concentrations (IC) implied that removal rates obtained were quite limited (ranging 3-8 g CH4 m(-3 )h(-1)); however, these results could be significantly increased (up to 20.6 g CH4 m(-3) h(-1)) at higher IC, which indicates that the mass transfer from the gas to the liquid layer surrounding the biofilm is a key limitation of the process.

Impact of short-term acidification on nitrification and nitrifying bacterial community dynamics in soilless cultivation media.

PubMed

Cytryn, Eddie; Levkovitch, Irit; Negreanu, Yael; Dowd, Scot; Frenk, Sammy; Silber, Avner

2012-09-01

Soilless medium-based horticulture systems are highly prevalent due to their capacity to optimize growth of high-cash crops. However, these systems are highly dynamic and more sensitive to physiochemical and pH perturbations than traditional soil-based systems, especially during nitrification associated with ammonia-based fertilization. The objective of this study was to assess the impact of nitrification-generated acidification on ammonia oxidation rates and nitrifying bacterial community dynamics in soilless growth media. To achieve this goal, perlite soilless growth medium from a commercial bell pepper greenhouse was incubated with ammonium in bench-scale microcosm experiments. Initial quantitative real-time PCR analysis indicated that betaproteobacterial ammonia oxidizers were significantly more abundant than ammonia-oxidizing archaea, and therefore, research focused on this group. Ammonia oxidation rates were highest between 0 and 9 days, when pH values dropped from 7.4 to 4.9. Pyrosequencing of betaproteobacterial ammonia-oxidizing amoA gene fragments indicated that r-strategist-like Nitrosomonas was the dominant ammonia-oxidizing bacterial genus during this period, seemingly due to the high ammonium concentration and optimal growth conditions in the soilless media. Reduction of pH to levels below 4.8 resulted in a significant decrease in both ammonia oxidation rates and the diversity of ammonia-oxidizing bacteria, with increased relative abundance of the r-strategist-like Nitrosospira. Nitrite oxidizers (Nitrospira and Nitrobacter) were on the whole more abundant and less sensitive to acidification than ammonia oxidizers. This study demonstrates that nitrification and nitrifying bacterial community dynamics in high-N-load intensive soilless growth media may be significantly different from those in in-terra agricultural systems.

Impact of Short-Term Acidification on Nitrification and Nitrifying Bacterial Community Dynamics in Soilless Cultivation Media

PubMed Central

Levkovitch, Irit; Negreanu, Yael; Dowd, Scot; Frenk, Sammy; Silber, Avner

2012-01-01

Soilless medium-based horticulture systems are highly prevalent due to their capacity to optimize growth of high-cash crops. However, these systems are highly dynamic and more sensitive to physiochemical and pH perturbations than traditional soil-based systems, especially during nitrification associated with ammonia-based fertilization. The objective of this study was to assess the impact of nitrification-generated acidification on ammonia oxidation rates and nitrifying bacterial community dynamics in soilless growth media. To achieve this goal, perlite soilless growth medium from a commercial bell pepper greenhouse was incubated with ammonium in bench-scale microcosm experiments. Initial quantitative real-time PCR analysis indicated that betaproteobacterial ammonia oxidizers were significantly more abundant than ammonia-oxidizing archaea, and therefore, research focused on this group. Ammonia oxidation rates were highest between 0 and 9 days, when pH values dropped from 7.4 to 4.9. Pyrosequencing of betaproteobacterial ammonia-oxidizing amoA gene fragments indicated that r-strategist-like Nitrosomonas was the dominant ammonia-oxidizing bacterial genus during this period, seemingly due to the high ammonium concentration and optimal growth conditions in the soilless media. Reduction of pH to levels below 4.8 resulted in a significant decrease in both ammonia oxidation rates and the diversity of ammonia-oxidizing bacteria, with increased relative abundance of the r-strategist-like Nitrosospira. Nitrite oxidizers (Nitrospira and Nitrobacter) were on the whole more abundant and less sensitive to acidification than ammonia oxidizers. This study demonstrates that nitrification and nitrifying bacterial community dynamics in high-N-load intensive soilless growth media may be significantly different from those in in-terra agricultural systems. PMID:22773643

Comparison of different packing materials for the biofiltration of air toxics.

PubMed

Sakuma, Takeyuki; Hattori, Toshihiro; Deshusses, Marc A

2006-11-01

Four different biofilter packing materials (two porous ceramics, perlite, and open pore polyurethane foam) were compared for the removal of toluene vapors. The focus was on evaluating performance at relatively short gas retention time (13.5 and 27 sec). The reactors were initially operated as biotrickling filters with continuous feeding and trickling of a nutrient solution. After significant plugging of the biotrickling filter beds with biomass was observed, the operation mode was switched to biofiltration with only periodic supply of mineral nutrients. This resulted in stable conditions, which allowed detailed investigations over > 6 months. The reactor packed with cattle bone Porcelite (CBP), a ceramic material containing some macronutrients and micronutrients, exhibited the highest performance. The critical load (i.e., load at which 95% removal occurred) was 29 g m(-3) hr(-1) at a gas retention time of 13.5 sec and 66 g m(-3) hr(-1) at a gas retention time of 27 sec. After the long-term experiment, the packing materials were taken from the reactors and examined. The reactors were divided into three sections, top, middle, and bottom, to determine whether spatial differentiation of biomass occurred. The assays included a double-staining technique to count total and live microorganisms and determination of moisture, protein, and dry weight contents. Microbial community analysis was also conducted by denaturing gradient gel electrophoresis. The results showed that most reactors had a significant fraction of inactive biomass. Comparatively, the CBP biofilter held significantly higher densities of active biomass, which may be the reason for the higher toluene removal performance. The analyses suggest that favorable material properties and the nutrients slowly released by the CBP provided better environmental conditions for the process culture.

Evaluation of three common green building materials for ozone removal, and primary and secondary emissions of aldehydes

NASA Astrophysics Data System (ADS)

Gall, Elliott; Darling, Erin; Siegel, Jeffrey A.; Morrison, Glenn C.; Corsi, Richard L.

2013-10-01

Ozone reactions that occur on material surfaces can lead to elevated concentrations of oxidized products in the occupied space of buildings. However, there is little information on the impact of materials at full scale, especially for green building materials. Experiments were completed in a 68 m3 climate-controlled test chamber with three certified green building materials that can cover large areas in buildings: (1) recycled carpet, (2) perlite-based ceiling tile and (3) low-VOC paint and primer on recycled drywall. Ozone deposition velocity and primary and secondary emission rates of C1 to C10 saturated carbonyls were determined for two chamber mixing conditions and three values of relative humidity. A direct comparison was made between ozone deposition velocities and carbonyl yields observed for the same materials analyzed in small (10 L) chambers. Total primary carbonyl emission rates from carpet, ceiling tile and painted drywall ranged from 27 to 120 μg m-2 h-1, 13 to 40 μg m-2 h-1, 3.9 to 42 μg m-2 h-1, respectively. Ozone deposition velocity to these three materials averaged 6.1 m h-1, 2.3 m h-1 and 0.32 m h-1, respectively. Total secondary carbonyl emissions from these materials ranged from 70 to 276 μg m-2 h-1, 0 to 12 μg m-2 h-1, and 0 to 30 μg m-2 h-1, respectively. Carbonyl emissions were determined with a transient approximation, and were found to be in general agreement with those found in the literature. These results suggest that care should be taken when selecting green building materials due to potentially large differences in primary and secondary emissions.

Comparison to the scanning electron microscope of professional dental hygiene methods on metal-free layered structures and metal-free monolithic structures processed by different polymerization cycles.

PubMed

Ermetici, M; Segù, M; Butera, A

2014-06-01

Aim of the study was to find effective instrumental methodologies and procedures for scaling and deplaquing without compromising the structure of metal-free, monolithic lithium disilicate and layered zirconia prosthetics. Of 14 decontaminated, extracted teeth in good anatomical condition, 7 veneers lithium disilicate monolithic and 7 layered zirconia crowns were prepared for testing and divided into 6 treatment groups. Each group was composed of a veneer and a crown. The division of the groups was carried out according to the type of treatment performed- instrumental carbon fiber and steel tips, prophylaxis paste with high and low RDA (Relative dentin abrasion), bicarbonate powder. Samples were examined and observed through a scanning electron microscope (SEM). Afterwards a detailed comparison of the images of treated and untreated samples was performed. The images were at the same magnification, thus showing the differences in the treated samples. The monolithic lithium disilicate presents minor damage to the surface but no excessive changes to the structure in general post treatment. The layered zirconia resulted in notable damage with evident abrasions on the layered ceramic structure after the use of ultrasound with a steel tip and air flow with bicarbonate. Carbon fibre tips and prophylaxis paste containing perlite and low RDA did not create notable changes to the properties of the materials in question. The results of the disilicate monolithic appear to show it to be a much more resistant material compared to layered zirconia in ceramic. Its resistance is demonstrated by the lack of notable damage in all the treatment groups.

Capability of selected crop plants for shoot mercury accumulation from polluted soils: phytoremediation perspectives.

PubMed

Rodriguez, Luis; Rincón, Jesusa; Asencio, Isaac; Rodríguez-Castellanos, Laura

2007-01-01

High-biomass crops can be considered as an alternative to hyperaccumulator plants to phytoremediate soils contaminated by heavy metals. In order to assess their practical capability for the absorption and accumulation of Hg in shoots, barley, white lupine, lentil, and chickpea were tested in pot experiments using several growth substrates. In the first experimental series, plants were grown in a mixture of vermiculite and perlite spiked with 8.35 microg g(-1) d.w. of soluble Hg. The mercury concentration of the plants' aerial tissues ranged from 1.51 to 5.13 microg g(-1) d.w. with lentil and lupine showing the highest values. In a second experiment carried out using a Hg-polluted soil (32.16 microg g(-1) d.w.) collected from a historical mining area (Almadén, Spain), the crop plants tested only reached shoot Hg concentration up to 1.13 microg g(-1) d.w. In the third experimental series, the Almadén soil was spiked with 1 microg g(-1) d.w. of soluble Hg; as a result, mercury concentrations in the plant shoots increased approximately 6 times for lupine, 5 times for chickpea, and 3.5 times for barley and lentil, with respect to those obtained with the original soil without Hg added. This marked difference was attributed to the low availability of Hg in the original Almadin soil and its subsequent increase in the Hg-spiked soil. The low mercury accumulation yields obtained for all plants do not make a successful decontamination of the Almadén soils possible byphytoremediation using crop plants. However, since the crops tested can effectively decrease the plant-available Hg level in this soil, their use could, to some extent, reduce the environmental risk of Hg pollution in the area.

[Study on Rapid Micropropagation in Vitro Technique of Guangfeng Medicinal Yam (Dioscorea opposita) Plantlets].

PubMed

Yin, Ming-Hua; Xu, Zhi-Jian; Zhang, Sheng-qin; Lv, Si-Jie; Zeng, Yan-hong; Fu, You-zhang; Hong, Sen-rong

2015-11-01

In order to provide methodology reference for virus-free and germplasm conservation of Guangfeng medicinal yam (Dioscorea opposita) plantlets, rapid micropropagation in vitro technique of Guangfeng medicinal yam plantlets was studied. Using the method of plant tissue culture, single factor test and flow-cytometry, the basic procedure of Guangfeng medicinal yam tissue culture was established and the DNA content of Guangfeng medicinal yam plantlets and its potted seedlings was detected. The best disinfection procedure of stems with a bud of Guangfeng medicinal yam was washed with sterile water for three times after sterilized with 70% alcohol for 20 - 30 s and then washed with sterile water for three times again after sterilized with 0.1% mercuric chloride for 10 - 12 min; The best explants of stems with a bud of Guangfeng medicinal yam was slightly woody and more mature stems witha bud; The best proliferation culture medium of stems with a bud of Guangfeng medicinal yam was MS + 6-BA 2.0 mg/L + NAA 0.1 mg/L; The best rooting culture medium of stems with a bud of Guangfeng medicinal yam was MS + NAA 0.5 mg/L; The best culture method of Guangfeng medicinal yam plantlets was liquid culture; The best transplanting matrix of Guangfeng medicinal yam plantlets was the mixture of paddy clay and fine sand (1: 2) or the mixture of perlite and vermiculite (1: 2); The DNA content between Guangfeng medicinal yam plantlets and its potted seedlings had no significant difference. A fast and efficient micropropagation in vitro technological system of stems with a bud of Guangfeng medicinal yam is established, and the flow cytometry detect results also show the genetic stability of Guangfeng medicinal yam plantlets, whose results provide the technical and theoretical basis for the large-scale production of Guangfeng medicinal yam plantlets.

Dark exposure of petunia cuttings strongly improves adventitious root formation and enhances carbohydrate availability during rooting in the light.

PubMed

Klopotek, Yvonne; Haensch, Klaus-Thomas; Hause, Bettina; Hajirezaei, Mohammad-Reza; Druege, Uwe

2010-05-01

The effect of temporary dark exposure on adventitious root formation (ARF) in Petuniaxhybrida 'Mitchell' cuttings was investigated. Histological and metabolic changes in the cuttings during the dark treatment and subsequent rooting in the light were recorded. Excised cuttings were exposed to the dark for seven days at 10 degrees C followed by a nine-day rooting period in perlite or were rooted immediately for 16 days in a climate chamber at 22/20 degrees C (day/night) and a photosynthetic photon flux density (PPFD) of 100micromolm(-2)s(-1). Dark exposure prior to rooting increased, accelerated and synchronized ARF. The rooting period was reduced from 16 days (non-treated cuttings) to 9 days (treated cuttings). Under optimum conditions, despite the reduced rooting period, dark-exposed cuttings produced a higher number and length of roots than non-treated cuttings. An increase in temperature to 20 degrees C during the dark treatment or extending the cold dark exposure to 14 days caused a similar enhancement of root development compared to non-treated cuttings. Root meristem formation had already started during the dark treatment and was enhanced during the subsequent rooting period. Levels of soluble sugars (glucose, fructose and sucrose) and starch in leaf and basal stem tissues significantly decreased during the seven days of dark exposure. This depletion was, however, compensated during rooting after 6 and 24h for soluble sugars in leaves and the basal stem, respectively, whereas the sucrose level in the basal stem was already increased at 6h. The association of higher carbohydrate levels with improved rooting in previously dark-exposed versus non-treated cuttings indicates that increased post-darkness carbohydrate availability and allocation towards the stem base contribute to ARF under the influence of dark treatment and provide energy for cell growth subject to a rising sink intensity in the base of the cutting. Copyright 2009 Elsevier GmbH. All rights reserved.

Quantification of fungal abundance on cultural heritage using real time PCR targeting the β-actin gene

PubMed Central

Ettenauer, Jörg; Piñar, Guadalupe; Tafer, Hakim; Sterflinger, Katja

2014-01-01

The traditional methodology used for the identification of microbes colonizing our cultural heritage was the application of cultivation methods and/or microscopy. This approach has many advantages, as living microorganisms may be obtained for physiological investigations. In addition, these techniques allow the quantitative and qualitative assessment of the investigated environment. Quantitative analyses are done by plate count and the determination of abundance by the colony forming unit (CFU). Nevertheless, these techniques have many drawbacks that lead to an underestimation of the cell numbers and do not provide a comprehensive overview of the composition of the inhabiting microbiota. In the last decades, several molecular techniques have been developed enabling many advantages over the cultivation approach. Mainly PCR-based, fingerprinting techniques allow a qualitative detection and identification of the microbiota. In this study, we developed a real time PCR method as a simple, rapid and reliable tool to detect and quantify fungal abundance using the β-actin gene, which is known to appear as a single-copy gene in fungi. To this end, five different indoor thermal insulation materials applied for historical buildings that were previously tested for their bio-susceptibility against various fungi were subjected to qPCR analyses. The obtained results were compared with those obtained from a previous study investigating the bio-susceptibility of the insulation materials using classical cultivation experiments. Both results correlated well, revealing that Perlite plaster was the most suitable insulation material, showing the lowest fungal CFU and qPCR values. In contrast, insulations made of wood showed to be not recommendable from the microbiological point of view. In addition, the potential of qPCR was tested in other materials of cultural heritage, as old parchments, showing to be a suitable method for measuring fungal abundance in these delicate materials. PMID:24904567

Concealing a shiny facial skin appearance by an Aerogel-based formula. In vitro and in vivo studies.

PubMed

Cassin, G; Diridollou, S; Flament, F; Adam, A S; Pierre, P; Colomb, L; Morancais, J L; Qiu, H

2018-02-01

To explore, in vitro and in vivo, the potential interest of an Aerogel-based formula, in concealing a naturally shiny facial skin. In vitro, various formulae and ingredients were applied as a thin film onto contrast plates and studied through measuring the shine induced following pump spraying of a mixture of oleic acid and mineral water as a sebum/sweat mix model. In such a test, an Aerogel ingredient led to very positive results. In vivo, two different formulae with various concentrations of Aerogel were randomly tested on half side of the face vs. bare side of Chinese women, under some provocative environmental conditions, known to enhance facial shine. These conditions comprised a normal activity under a hot and highly humid summer time followed - or not - by a hamam session. Both studies included comparative evaluations using a half-face procedure (treated/untreated or vehicle). In the first case, evaluations were quantitatively carried out, whereas the second one was based on a quantitative self-evaluations from standardized full-face photographs RESULTS: In vitro, the tested Aerogel, incorporated at 1% or 2% concentration in a common O/W cosmetic emulsion, shows an immediate light scattering effect, thereby masking shine. Such effect appears of much higher amplitude than that of two other tested particulate ingredients (Talc and Perlite). A noticeable remanence of anti-shine effect was confirmed in vivo in extreme conditions. The latter was self-perceived by all participants in the second study. This result is likely related to the super hydrophobic behaviour of the Aerogel. As cosmetic ingredient, this new Aerogel appears as a highly promising ingredient for concealing the facial skin shine, a source of complaint from many consumers living in hot and humid regions. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Design and development of green roof substrate to improve runoff water quality: plant growth experiments and adsorption.

PubMed

Vijayaraghavan, K; Raja, Franklin D

2014-10-15

Many studies worldwide have investigated the potential benefits achievable by transforming brown roofs of buildings to green roofs. However, little literature examined the runoff quality/sorption ability of green roofs. As the green roof substrate is the main component to alter the quality of runoff, this investigation raises the possibility of using a mixture of low-cost inorganic materials to develop a green roof substrate. The tested materials include exfoliated vermiculite, expanded perlite, crushed brick and sand along with organic component (coco-peat). Detailed physical and chemical analyses revealed that each of these materials possesses different characteristics and hence a mix of these materials was desirable to develop an optimal green roof substrate. Using factorial design, 18 different substrate mixes were prepared and detailed examination indicated that mix-12 exhibited desirable characteristics of green roof substrate with low bulk density (431 kg/m(3)), high water holding capacity (39.4%), air filled porosity (19.5%), and hydraulic conductivity (4570 mm/h). The substrate mix also provided maximum support to Portulaca grandiflora (380% total biomass increment) over one month of growth. To explore the leaching characteristics and sorption capacity of developed green roof substrate, a down-flow packed column arrangement was employed. High conductivity and total dissolved solids along with light metal ions (Na, K, Ca and Mg) were observed in the leachates during initial stages of column operation; however the concentration of ions ceased during the final stages of operation (600 min). Experiments with metal-spiked deionized water revealed that green roof substrate possess high sorption capacity towards various heavy metal ions (Al, Fe, Cr, Cu, Ni, Pb, Zn and Cd). Thus the developed growth substrate possesses desirable characteristics for green roofs along with high sorption capacity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dynamics of Short-Term Phosphorus Uptake by Intact Mycorrhizal and Non-mycorrhizal Maize Plants Grown in a Circulatory Semi-Hydroponic Cultivation System.

PubMed

Garcés-Ruiz, Mónica; Calonne-Salmon, Maryline; Plouznikoff, Katia; Misson, Coralie; Navarrete-Mier, Micaela; Cranenbrouck, Sylvie; Declerck, Stéphane

2017-01-01

A non-destructive cultivation system was developed to study the dynamics of phosphorus (Pi) uptake by mycorrhizal and non-mycorrhizal maize plantlets. The system consisted of a plant container connected via silicon tubes to a glass bottle containing a nutrient solution supplemented with Pi. The nutrient solution is pumped with a peristaltic pump to the upper part of the container via the silicon tubes and the solution percolate through the plantlet container back into the glass bottle. Pi is sampled from the glass bottle at regular intervals and concentration evaluated. Maize plantlets were colonized by the AMF Rhizophagus irregularis MUCL 41833 and Pi uptake quantified at fixed intervals (9, 21, and 42 h) from the depletion of the Pi in the nutrient solution flowing through the plantlets containers. Plants and fungus grew well in the perlite substrate. The concentration of Pi in the bottles followed an almost linear decrease over time, demonstrating a depletion of Pi in the circulating solution and a concomitant uptake/immobilization by the plantlet-AMF associates in the containers. The Pi uptake rate was significantly increased in the AMF-colonized plantlets (at 9 and 21 h) as compared to non-colonized plantlets, although no correlation was noticed with plant growth or P accumulation in shoots. The circulatory semi-hydroponic cultivation system developed was adequate for measuring Pi depletion in a nutrient solution and by corollary Pi uptake/immobilization by the plant-AMF associates. The measurements were non-destructive so that the time course of Pi uptake could be monitored without disturbing the growth of the plant and its fungal associate. The system further opens the door to study the dynamics of other micro and macro-nutrients as well as their uptake under stressed growth conditions such as salinity, pollution by hydrocarbon contaminants or potential toxic elements.

Salinity alters curcumin, essential oil and chlorophyll of turmeric (Curcuma longa L.).

PubMed

Mostajeran, A; Gholaminejad, A; Asghari, G

2014-01-01

Turmeric (Curcuma longa L.) is a perennial rhizomatous plant from the family of Zingibraceae, native in South Asia. The main components of turmeric are curcuminoids and essential oil which are responsible for turmeric characteristic such as odor and taste. Due to the large areas of saline land in Iran and less information related to cultivation of turmeric, in this research, the effect of salinity on growth, curcumin and essential oil of turmeric was evaluated. Rhizomes were planted in coco peat and perlite for germination. Then uniform germinated rhizomes transferred to hydroponic condition containing Hoagland's solution. Two months old plants were exposed to salinity (0, 20, 60 and 100 mM NaCl) for two months via hydroponic media using Hoagland's solution. Then dry weight of different plant parts, chlorophyll, curcumin and essential oil components of turmeric were determined. The result indicated that, dry weight reductions in 100 mM NaCl were 191%, 141%, 56%, 30% in leaf, pseudo-stem, root and rhizome, respectively (This is almost equal to 6.9, 2.87, 0.34 and 0.23 mg plant(-1) mM(-1)NaCl reduction of dry weight, respectively). The reductions in chlorophyll a and b are almost 3.32 and 0.79 μg/gFW respectively due to one unit addition of NaCl (P < 0.05). The addition of curcumin of rhizome for four months old plant versus three months were almost 5 fold for 0 mM NaCl and 2 fold for 100 mM NaCl due to one month of delay in harvest. Low salinity has positive effect in curcumin production but higher salinity (higher than 60 mM) had adverse effect and causes 24% reduction of curcumin compared to control plants. There were more para-cymene and terpineol in volatile oils of turmeric rhizome than the other components, most of the volatile oil compounds were unchanged or varied slightly as salinity changed.

Biofiltration of solvent vapors from air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Young-sook.

1993-01-01

For various industrial solvent vapors, biofiltration promises to offer a cost-effective emission control technology. Exploiting the full potential of this technology will help attain the goals of the Clean Air Act Amendments of 1990. Concentrating on large volumes of volatile industrial solvents, stable multicomponent microbial enrichments capable of growing a mineral medium with solvent vapors as their only source of carbon and energy were obtained from soil and sewage sludge. These consortia were immobilized on an optimized porous solid support (ground peat moss and perlite). The biofilter material was packed in glass columns connected to an array of pumps andmore » flow meters that allowed the independent variation of superficial velocity and solvent vapor concentrations. In various experiments, single solvents, such as methanol, butanol, acetonitrile, hexane and nitrobenzene, and solvent mixtures, such as benzene-toluene-xylene (BTX) and chlorobenzene-o-dichlorobenzene (CB/DCB) were biofiltered with rates ranging from 15 to334 g solvent removed per m[sup 3] filter volume /h. Pressure drops were low to moderate (0-10 mmHg/m) and with periodic replacement of moisture, the biofiltration activity could be maintained for a period of several months. The experimental data on methanol biofiltration were subjected to mathematical analysis and modeling by the group of Dr. Baltzis at NJIT for a better understanding and a possible scale up of solvent vapor biofilters. In the case of chlorobenzenes and nitrobenzene, the biofilter columns had to be operated with water recirculation in a trickling filter mode. To prevent inactivation of the trickling filter by acidity during CB/DCB removal, pH control was necessary, and the removal rate of CB/DCB was strongly influenced by the flow rate of the recyling water. Nitrobenzene removal in a trickling filter did not require pH control, since the nitro group was reduced and volatilized as ammonia.« less

Cadmium induces hypodermal periderm formation in the roots of the monocotyledonous medicinal plant Merwilla plumbea

PubMed Central

Lux, Alexander; Vaculík, Marek; Martinka, Michal; Lišková, Desana; Kulkarni, Manoj G.; Stirk, Wendy A.; Van Staden, Johannes

2011-01-01

Background and Aims Merwilla plumbea is an important African medicinal plant. As the plants grow in soils contaminated with metals from mining activities, the danger of human intoxication exists. An experiment with plants exposed to cadmium (Cd) was performed to investigate the response of M. plumbea to this heavy metal, its uptake and translocation to plant organs and reaction of root tissues. Methods Plants grown from seeds were cultivated in controlled conditions. Hydroponic cultivation is not suitable for this species as roots do not tolerate aquatic conditions, and additional stress by Cd treatment results in total root growth inhibition and death. After cultivation in perlite the plants exposed to 1 and 5 mg Cd L−1 in half-strength Hoagland's solution were compared with control plants. Growth parameters were evaluated, Cd content was determined by inductively coupled plasma mass spectroscopy (ICP-MS) and root structure was investigated using various staining procedures, including the fluorescent stain Fluorol yellow 088 to detect suberin deposition in cell walls. Key Results The plants exposed to Cd were significantly reduced in growth. Most of the Cd taken up by plants after 4 weeks cultivation was retained in roots, and only a small amount was translocated to bulbs and leaves. In reaction to higher Cd concentrations, roots developed a hypodermal periderm close to the root tip. Cells produced by cork cambium impregnate their cell walls by suberin. Conclusions It is suggested that the hypodermal periderm is developed in young root parts in reaction to Cd toxicity to protect the root from radial uptake of Cd ions. Secondary meristems are usually not present in monocotyledonous species. Another interpretation explaining formation of protective suberized layers as a result of periclinal divisions of the hypodermis is discussed. This process may represent an as yet unknown defence reaction of roots when exposed to elemental stress. PMID:21118841

The Effect of Plant Cultivar, Growth Media, Harvest Method and Post Harvest Treatment on the Microbiology of Edible Crops

NASA Technical Reports Server (NTRS)

Hummerick, Mary P.; Gates, Justin R.; Nguyen, Bao-Thang; Massa, Gioia D.; Wheeler, Raymond M.

2011-01-01

Systems for the growth of crops in closed environments are being developed and tested for potential use in space applications to provide a source of fresh food. Plant growth conditions, growth media composition and harvest methods can have an effect on the microbial population of the plant, and therefore should be considered along with the optimization of plant growth and harvest yields to ensure a safe and palatable food crop. This work examines the effect of plant cultivar, growth media, and harvest method on plant microbial populations. Twelve varieties of leafy greens and herbs were grown on a mixture of Fafard #2 and Arcillite in the pillow root containment system currently being considered for the VEGGIE plant growth unit developed by Orbitec. In addition, ,Sierra and Outredgeous lettuce varieties were grown in three different mixtures (Fafard #2, Ardllite, and Perlite/Vermiculite). The plants were analyzed for microbial density. Two harvest methods, "cut and come again" (CACA) and terminal harvest were also compared. In one set ofexpe'riments red leaf lettuce and mizuna were grown in pots in a Biomass Production System for education. Plants were harvested every two weeks by either method. Another set of experiments was performed using the rooting pillows to grow 5 varieties of leafy greens and cut harvesting at different intervals. Radishes were harvested and replanted at two-week intervals. Results indicate up to a 3 IOglO difference in microbial counts between some varieties of plants. Rooting medium resulted in an approximately 2 IOglO lower count in the lettuce grown in arscillite then those grown in the other mixtures. Harvest method and frequency had less impact on microbial counts only showing a significant increase in one variety of plant. Post harvest methods to decrease the bacterial counts on edible crops were investigated in these and other experiments. The effectiveness of PRO-SAN and UV-C radiation is compared.

Salinity alters curcumin, essential oil and chlorophyll of turmeric (Curcuma longa L.)

PubMed Central

Mostajeran, A.; Gholaminejad, A.; Asghari, G.

2014-01-01

Turmeric (Curcuma longa L.) is a perennial rhizomatous plant from the family of Zingibraceae, native in South Asia. The main components of turmeric are curcuminoids and essential oil which are responsible for turmeric characteristic such as odor and taste. Due to the large areas of saline land in Iran and less information related to cultivation of turmeric, in this research, the effect of salinity on growth, curcumin and essential oil of turmeric was evaluated. Rhizomes were planted in coco peat and perlite for germination. Then uniform germinated rhizomes transferred to hydroponic condition containing Hoagland's solution. Two months old plants were exposed to salinity (0, 20, 60 and 100 mM NaCl) for two months via hydroponic media using Hoagland's solution. Then dry weight of different plant parts, chlorophyll, curcumin and essential oil components of turmeric were determined. The result indicated that, dry weight reductions in 100 mM NaCl were 191%, 141%, 56%, 30% in leaf, pseudo-stem, root and rhizome, respectively (This is almost equal to 6.9, 2.87, 0.34 and 0.23 mg plant-1 mM-1NaCl reduction of dry weight, respectively). The reductions in chlorophyll a and b are almost 3.32 and 0.79 μg/gFW respectively due to one unit addition of NaCl (P < 0.05). The addition of curcumin of rhizome for four months old plant versus three months were almost 5 fold for 0 mM NaCl and 2 fold for 100 mM NaCl due to one month of delay in harvest. Low salinity has positive effect in curcumin production but higher salinity (higher than 60 mM) had adverse effect and causes 24% reduction of curcumin compared to control plants. There were more para-cymene and terpineol in volatile oils of turmeric rhizome than the other components, most of the volatile oil compounds were unchanged or varied slightly as salinity changed. PMID:25598799

Efficacy of microorganisms selected from compost to control soil-borne pathogens.

PubMed

Pugliese, M; Gullino, M L; Garibaldi, A

2010-01-01

Suppression of soil-borne plant pathogens with compost has been widely studied. Compost has been found to be suppressive against several soil-borne pathogens in various cropping systems. However, an increase of some diseases due to compost usage has also been observed, since compost is a product that varies considerably in chemical, physical and biotic composition, and, consequently, also in ability to suppress soil borne diseases. New opportunities in disease management can be obtained by the selection of antagonists from suppressive composts. The objective of the present work was to isolate microorganisms from a suppressive compost and to test them for their activity against soil-borne pathogens. A compost from green wastes, organic domestic wastes and urban sludge's that showed a good suppressive activity in previous trials was used as source of microorganisms. Serial diluted suspensions of compost samples were plated on five different media: selective for Fusarium sp., selective for Trichoderma sp., selective for oomycetes, potato dextrose agar (PDA) for isolation of fungi, lysogeny broth (LB) for isolation of bacteria. In total, 101 colonies were isolated from plates and tested under laboratory conditions on tomato seedlings growing on perlite medium in Petri plates infected with Fusarium oxysporum f.sp. radicis-lycopersici and compared to a commercial antagonist (Streptomyces griserovidis, Mycostop, Bioplanet). Among them, 28 showed a significant disease reduction and were assessed under greenhouse condition on three pathosystems: Fusarium oxysporum f.sp. basilica/basil, Phytophthora nicotianae/tomato and Rhizoctonia solani/bean. Fusarium spp. selected from compost generally showed a good disease control against Fusarium wilts, while only bacteria significantly controlled P. nicotianae on tomato under greenhouse conditions. None of the microorganisms was able to control the three soil-borne pathogens together, in particular Rhizoctonia solani. Results confirmed the good suppressive activity of the compost under study against soil-borne pathogens. The selection of antagonists from compost is a promising strategy for the development of new biological control agents against soil-borne pathogens.

Suppression of Pythium spp. by Trichoderma spp. during germination of tomato seeds in soilless growing media.

PubMed

Aerts, R; De Schutter, B; Rombouts, L

2002-01-01

In the Flemish horticulture Pythium spp. is an important pathogen of tomato plants (Lycopersicon esculenthum) in soilless growing media. Therefore some experiments were conducted to evaluate the possibility of decreasing the damage caused by Pythium spp. by Trichoderma spp. In a tray with several growing media, a suspension of Trichoderma conidia (10(6)/ml growing medium) was applied two weeks before sowing. On some objects, a compost extract (Biostimulus) was added. The growing media used in the experiment were rockwool, recycled rockwool and recycled coconut fibre. After sowing, the trays were covered with perlite. Three isolates of Trichoderma spp.: T. asperellum (Biofungus), T. harzianum (Tri 003) and Trichoderma sp. (KHK) and two isolates of Pythium spp.: P. ultimum (MUCL) en P. aphanidermatum (HRI, UK) were used. Propamocarb was used as a chemical standard. The use of coconut fibre growing medium resulted in a higher percentage (36%) of germination than the rockwool media when only Pythium spp. was used. The presence of the spontaneous developing microflora in the coconut fibre medium gave probably also a suppression of Pythium spp. For that reason the results of the suppression by Trichoderma spp. are not easy to explain and very variable on the different objects. Pythium ultimum was more suppressed than P. aphanidermatum on all the growing media and the application of all the Trichoderma isolates increased the germination percentage of tomato seeds. T. asperellum (Biofungus) gave on rockwool also a good result for the suppression of P. aphanidermatum (increasing of germination with 48%). This effect was comparable with the propamocarb treatment (48%). T. harzianum (Tri 003) gave a small suppression (22%) and Trichoderma sp. (KHK) gave almost no suppression of P. aphanidermatum (7%). When less Trichoderma conidia were applied the germination percentage decreased. The adding of a compost extract (Biostimulus) had no influence on the results. This experiment shows that application of Trichoderma conidia in the presence of Pythium spp. increases the germination percentage of tomato seeds, sowed in the used soilless growing media.

Principal Factors for High Performance of Odor and Methane degrading Biocover using Network Analysis

NASA Astrophysics Data System (ADS)

Jung, H.; Yun, J.; O, G. C.; Ryu, H. W.; Jeon, J. M.; Cho, K. S.

2016-12-01

Methane is 25 times more powerful greenhouse gas than carbon dioxide and plays an important role in global warming. Landfills are one of the biggest methane sources and have emitted 37% of anthropogenic methane in Korea. Applying biocovers in landfills is known to be efficient for the simultaneous mitigation of methane as well as odor which occurs severe civil claims. In this study, three pilot-scale biocovers (2.5mx5mx1m) were constructed in a sanitary landfill at Gwangyang, Korea to establish the optimal operational conditions of biocover. All biocovers are filled with soil, EG microbial agent, food waste compost, and perlite with different combination. Pilot-scale biocovers have been operated since January in this year for simultaneous removal of odor and methane. The concentrations of methane and odors such as ammonia, H2S, methyl mercaptane, methylsulfide, dimetyl disulfide, i-valeraldehyde, and styrene were measured at the inlet and outlet of biocovers each month using GC and HPLC for removal performance evaluation. The biocover with highest removal efficiency eliminated 98.4% of odor and 100.0% of methane. All removal efficiencies of odor measured during experiment are in 81.1 98.4% range, and those of methane are in 3.6 100.0%. Three months later after biocover construction, all biocovers with mixed packing material showed better methane degradation performance than the biocovers packed only with soil. The packing materials of biocovers were sampled during winter (January), spring (April) and summer (July), and their microbial communities were examined based on 16S rDNA using 454 pyrosequencing to detect microbial factors that affects the removal efficiency. Methanotrophs which are known as methane-degradable bacteria take 10 25% of microbial community in biocovers, and most of those found in biocovers are type methanothrophs. Network analysis is performed and principal factors for performance improvement of biocovers are derived. Based on this study, well-designed biocovers will be newly set up in the operational landfill with the consideration of derived principal factors for high efficiency. This research was supported by the Korea Ministry of Environment as a "Converging Technology Project (2015001640003)".

Mineral Resources of the Mount Nutt Wilderness Study Area, Mohave County, Arizona

USGS Publications Warehouse

Gray, Floyd; Jachens, Robert C.; Miller, Robert J.; Turner, Robert L.; Livo, Eric K.; Knepper, Daniel H.; Mariano, John; Almquist, Carl L.

1990-01-01

The Mount Nutt Wilderness Study Area (AZ-020-024) is located in the Black Mountains about 15 mi west of Kingman, Arizona. At the request of the U.S. Bureau of Land Management, approximately 27,210 acres of the wilderness study area was evaluated for mineral resources (known) and mineral resource potential (undiscovered). In this report, the area studied is referred to as the 'wilderness study area' or simply 'the study area'; any reference to the Mount Nutt Wilderness Study Area refers only to that part of the wilderness study area (27,210 acres) for which a mineral survey was requested. The U.S. Geological Survey and the U.S. Bureau of Mines conducted geological, geochemical, and geophysical surveys to assess the identified mineral resources and mineral resource potential of the study area. Fieldwork for this report was carried out in 1987 and 1988. A gold resource totaling at least 56,000 troy oz has been identified at two sites in Secret Pass Canyon, less than 0.5 mi north of the study area. No other metallic mineral resources were identified inside the study area. An area near the center of the study area contains fire agate, a gem stone. On the basis of tonnage, site accessibility, and current production methods, this area is considered an indicated subeconomic fire-agate resource for the foreseeable future. Sand and gravel are present in the study area. An area surrounding the Tincup mine and including a small portion of the extreme north-central part of the study area has high potential for gold and low potential for silver, lead, and mercury. Three areas in the extreme northwestern, north-central, and southwestern parts of the study area have moderate potential for gold and low potential for silver, lead, and mercury. A small area near the known fire-agate resource in the south-central part of the study area has low potential for fire agate. Large areas in the eastern and central parts of the study area have low potential for perlite and zeolite resources. The entire study area has no potential for oil and gas and no potential for geothermal resources.

Crop and Substrate Tests with Single Use Rooting "Pillows" for the VEGGIE Plant Growth Hardware

NASA Technical Reports Server (NTRS)

Massa, Gioia; Newsham, Gerard; Caro, Janicce; Stutte, Gary; Morrow, Robert; Wheeler, Raymond

2011-01-01

VEGGIE is a small plant production chamber built by ORBITEC. This chamber can be collapsed for easy stowage and deployed in orbit. It is designed for gravity independent operation, and provides 0.17 square m of crop growth area with three primary subsystems: an LED light panel, extendable transparent Teflon bellows to enclose the plants, and a wicking reservoir. VEGGIE would provide the capability for astronauts to grow fresh foods for dietary supplementation. Initial planting concepts tested with the VEGGIE included direct seeding or plug placement on the reservoir surface. These options had issues of salt accumulation and eventual toxicity if the reservoir was filled with nutrient solution, and hardware reuse was limited due to sanitation. In response a rooting packet or "pillow" concept was developed: single-use bags of media containing time release fertilizer with a wicking surface contacting the VEGGIE reservoir. Pillows being tested are small electrostatic bags with a Nitex nylon mesh side, each holding 100 mL of dry media. Six pillows fit in one VEGGIE unit; however pillow size could vary depending on crop selected. Seeds can be planted directly in pillows and planted pillows can be hydrated in space as desired. Our goals were to define optimal media and crops for an ISS mission scenario. Plant tests in pillows were performed in a controlled environment chamber set to habitat-relevant conditions, and capillary reservoir analogs were utilized. Media tested within pillows included: a commercial peat-based potting mix, arcillite (calcined clay), perlite: vermiculite, and peat-based: arcillite blends. Testing included 15 types of leafy greens, snow pea, radish, and herbs. Media performance was crop dependent, but generally plants showed the greatest growth in the peat-based: arcillite mixes. Crops with the best performance in pillows were identified, and testing is underway with select leafy greens examining plant and microbial load response to repeated harvest. We plan to use findings from previous flight testing with media to evaluate the effects of capillary flow from the reservoir to pillows in microgravity.

Investigation of Creep Processes and Microdamages in 10Kh9V2MFBR-Sh High-Chromium Steel

NASA Astrophysics Data System (ADS)

Grin', E. A.; Pchelintsev, A. V.

2018-01-01

During the modernization and the new construction of power units at TPPs in Russia, high-chromium martensitic steels with higher heat-resistant properties than the traditional perlite steels are increasingly used as structural materials. High-chromium steels have a necessary regulatory support for their use in domestic power engineering. However, up to the present time, the issue of assessing the quality of these steels at the analysis of their state during long-term operation remains open. The article proposed is one of the first attempts to create a system of quality criteria for martensitic steels based on their microdamage parameters. Tests were carried out on the long-term strength and creep of samples from 10Kh9V2MFBR-Sh steel at high temperatures with the construction of creep curves in relative coordinates "deformation related to the deformation of fracture, current time related to time to failure." For some samples, the tests were interrupted and the metal was subjected to metallographic studies consisting of the analysis of microdamage with reference to the accumulated creep strain. It has been shown experimentally that the deformation curve of high-chromium steel differs from the analogous curve of pearlitic steel by a longer and flat section of steady creep and by a sharper transition to the third accelerated creep stage, which has a very short time period (approximately 10% of the total durability). The tendency to the increase in the microdamage of the structure of steel as the accumulated creep strain increases with time was confirmed. The beginning of transition to the final creep phase is characterized by the formation of contours of future pore chains and by the appearance of individual large pores of up to 6 μm in size, the presence of which in the microstructure of the martensitic steel indicates a very significant accumulation of creep strain, and corresponds to the predestruction stage of metal. It is necessary to continue the research to obtain quantitative indicators on the accumulation of microdamage in high-chromium steel in a conjunction with the development of a metal resource under creep conditions.

Utilization and Conversion of Sewage Sludge as Metal Sorbent

NASA Astrophysics Data System (ADS)

Gong, Xu Dong; Li, Loretta Y.

2013-04-01

Most biosolids are disposed on land. With improvements in wastewater treatment processes and upgrading of treatment plants across Canada, biosolids generation will increase dramatically. These biosolids will need to be dealt with because they contain various contaminants, including heavy metals and several classes of emerging contaminants. A number of researchers have recently focused on preparation of sewage sludge-based adsorbents by carbonation, physical activation and chemical activation for decontamination of air and wastewater. These previous studies have indicated that sludge-based activated carbon can have good adsorption performance for organic substances in dye wastewater. The overall results suggest that activated carbon from sewage sludge can produce a useful adsorbent, while also reducing the amount of sewage sludge to be disposed. However, sludge-derived activated carbon has not been extensively studied, especially for adsorption of heavy metal ions in wastewater and for its capacity to remove emerging contaminants, such as poly-fluorinated compounds (PFCs). Previous research has indicated that commercial activated carbons adsorb organic compounds more efficiently than heavy metal ions. 45 Activated carbon can be modified to enhance its adsorption capacity for special heavy metal ions,46 e.g. by addition of inorganic and organic reagents. The modifications which are successful for commercial activated carbon should also be effective for sludge-derived activated carbon, but this needs to be confirmed. Our research focuses on (a) investigation of techniques for converting sewage sludge (SS) to activated carbon (AC) as sorbents; (b) exploration of possible modification of the activated carbon (MAC) to improve its sorption capacity; (c) examination of the chemical stability of the activated carbon and the leachability of contaminants from activated carbon,; (d) comparison of adsorptivity with that of other sorbents. Based on XRD and FT-IR, we successfully converted SS to AC and further modified it to improve absorption. SSMAC has large specific surface areas based on the BET technique. Batch adsorption results indicate that metal adsorption for SSMAC > SSAC, with adsorption occurring within the first 5 minutes of contact. Comparison of the adsorptivity of various sorbents such as commercial activated carbon (CAC), mineral sorbents such as perlite, clinoptilolite and illite indicates that SSMAC × CAC × clinoptilolite > kaolite.

Developing suitable methods for effective characterization of electrical properties of root segments

NASA Astrophysics Data System (ADS)

Ehosioke, Solomon; Phalempin, Maxime; Garré, Sarah; Kemna, Andreas; Huisman, Sander; Javaux, Mathieu; Nguyen, Frédéric

2017-04-01

The root system represents the hidden half of the plant which plays a key role in food production and therefore needs to be well understood. Root system characterization has been a great challenge because the roots are buried in the soil. This coupled with the subsurface heterogeneity and the transient nature of the biogeochemical processes that occur in the root zone makes it difficult to access and monitor the root system over time. The traditional method of point sampling (root excavation, monoliths, minirhizotron etc.) for root investigation does not account for the transient nature and spatial variability of the root zone, and it often disturbs the natural system under investigation. The quest to overcome these challenges has led to an increase in the application of geophysical methods. Recent studies have shown a correlation between bulk electrical resistivity and root mass density, but an understanding of the contribution of the individual segments of the root system to that bulk signal is still missing. This study is an attempt to understand the electrical properties of roots at the segment scale (1-5cm) for more effective characterization of electrical signal of the full root architecture. The target plants were grown in three different media (pot soil, hydroponics and a mixture of sand, perlite and vermiculite). Resistance measurements were carried out on a single segment of each study plant using a voltmeter while the diameter was measured using a digital calliper. The axial resistance was calculated using the measured resistance and the geometric parameters. This procedure was repeated for each plant replica over a period of 75 days which enabled us to study the effects of age, growth media, diameter and length on the electrical response of the root segments of the selected plants. The growth medium was found to have a significant effect on the root electrical response, while the effect of root diameter on their electrical response was found to vary among the plants. More work is still required to further validate these results and also to develop better systems to study the electrical behaviour of root segments. Findings from our review entitled "an overview of the geophysical approach to root investigation", suggest that SIP and EIT geophysical methods could be very useful for root investigations, thus more work is in progress to develop these systems for assessing the root electrical response at various scales.

Subaqueous non-vesicular to poorly-vesicular shards: hydroclastic fragmentation on seamounts and summit calderas

NASA Astrophysics Data System (ADS)

Mueller, W. U.; Dingwell, D. B.; Downey, W. S.; Mastin, L. G.

2008-12-01

Recognizing pyroclastic deposits that originate directly from magmatic and phreatomagmatic explosions in a subaqueous setting is based upon sedimentary structures, such as massive, stratified, and graded beds as well as (pyro)clast size. Ideally such deposits form ordered fining-and thinning-upward sequences. Pumice, scoria, glass shards, euhedral and broken crystals, and lithic fragments are constituents that support an explosive heritage. Recent deep-sea ROV and submersible dives have retrieved non-vesicular to vesicle- poor, mm-scale, mafic shards in 5-15 cm-thick massive and/or graded (stratified) deposits, for which a subaqueous explosive origin has been inferred. These sheet hyaloclastites with variable shard shapes were first documented on Seamount 6 as deep-sea Limu O Pele at water depths > 1000 m. We identified in Seamount 6 samples equant to blocky shards with angular to subrounded terminations, but also subordinate hair-like and contorted glassy filaments, warped shards and irregular shards. Shards display internal laminations (flow-banding?) and have local perlitic fractures. Bubble wall shards derived from scoria burst were rare. In combination with all the above and a poor shard vesicularity (< 2%), a magmatic explosive origin seems improbable. Such small-volume deposits have been reported from seamounts and summit calderas associated with subaqueous drainage tubes and ponded magma in depths > 1000 m. We envision that hydrostatic pressure commensurate with water depth played a significant role. The deposits can be readily explained by a hydroclastic process whereby fragmentation occurred at the milli-second (Limu) to second scale (hyaloclastite). Hence, hyperquenched glass shards or thread-like glass filaments need not require magmatic explosivity. Constant surface interaction between aphyric, low-viscosity, high temperature, magma-lava at depth with seawater causes fragmentation (granulation) that can generate such delicate shards. The transfer of heat to the ambient medium, seawater, favours turbulent convection causing strong water movement that strips glassy rinds and lofts the fine-grained shards and Limu O Pele into the water column. Once entrained, shards are deposited after water turbulence abates. Congestion of the water column causes deposition from low-density turbidity currents and subaqueous fallout. In this manner delicate textures would remain intact even if removed from the site of hydroclastic fragmentation.

Primary welding and crystallisation textures preserved in the intra-caldera ignimbrites of the Permian Ora Formation, northern Italy: implications for deposit thermal state and cooling history

NASA Astrophysics Data System (ADS)

Willcock, M. A. W.; Cas, R. A. F.

2014-06-01

Exceptional exposure through a Permian intra-caldera ignimbrite fill within the 42 × 40 km Ora caldera (>1,290 km3 erupted volume) provides an opportunity to study welding textures in a thick intra-caldera ignimbrite succession. The ignimbrite succession records primary dense welding, a simple cooling unit structure, common crystallisation zones, and remarkably preserves fresh to slightly hydrated glass in local vitrophyre zones. Evidence for primary syn- and post-emplacement welding consists of (a) viscously deformed and sintered juvenile glass and relict shard textures; (b) complete deposit welding; (c) subtle internal welding intensity variations; (d) vitrophyre preserved locally at the base of the ignimbrite succession; (e) persistent fiamme juvenile clast shapes throughout the succession at the macroscopic and microscopic scales, defining a moderate to well-developed eutaxitic texture; (f) common undulating juvenile clast (pumice) margins and feathery terminations; (g) a general loss of deposit porosity; and (h) perlitic fracturing. A low collapsing or fountaining explosive eruption column model is proposed to have facilitated the ubiquitous welding of the deposit, which in turn helped preserve original textures. The ignimbrite succession preserves no evidence of a time break through the sequence and columnar joints cross-gradational ignimbrite lithofacies boundaries, so the ignimbrite is interpreted to represent a simple cooling unit. Aspect ratio and anisotropy of magnetic susceptibility (AMS) analyses through stratigraphic sections within the thick intra-caldera succession and at the caldera margin reveal variable welding compaction and strain profiles. Significantly, these data show that welding degree/intensity may vary in an apparently simple cooling unit because of variations in eruption process recorded in differing lithofacies. These data imply complex eruption, emplacement, and cooling processes. Three main crystallisation textural zones are identified in the ignimbrite succession: localised vitrophyre zones, widespread microcrystalline to sparsely spherulitic pseudomorphed vitriclastic textural zones, and thick granophyric zones. These zones record a typical spectrum from rapid to prolonged cooling. The non-uniform crystallisation patterns reflect variations in deposit thickness, the relative position of deposits within the larger ignimbrite succession, the type of substrate material, and the degree of confinement in the intra-caldera setting. We support previous work suggesting that traditional welding classifications (e.g. Smith, US Geological Survey Professional Paper 354-F 1960b) are most appropriate for use within altered and/or ancient ignimbrite successions.

Differential tolerance of 3 self-rooted Citrus limon cultivars to NaCl stress.

PubMed

Tsabarducas, V; Chatzistathis, T; Therios, I; Koukourikou-Petridou, M; Tananaki, C

2015-12-01

One-year-old self-rooted cuttings of three Citrus limon cultivars (Nouvel Athos, Lisbon, Maglini) were grown in 1 L black plastic bags, containing a mixture of sand: perlite (1:1), in order to investigate: i) if genotypic differences to salt stress existed, ii) if KNO3 can alleviate salinity stress, iii) the role of carbohydrates (such as the sugars fructose, glucose and sucrose) and proline as possible osmoregulators in C. limon osmoprotection, and iv) if genotypic differences to salt stress tolerance exist among the 3 studied cultivars. The experiment included 3 treatments: i) control (C), i.e. 25% modified Hoagland (No2) solution (MHS)-NaCl, ii) T1, 25% MHS+80 mM NaCl, iii) T2, 25% MHS+80 mM NaCl+5 mM KNO3. Plant growth was negatively affected by high NaCl (T1); the highest Cl and Na quantities have been absorbed by Lisbon, while the lowest ones by Maglini. Salt stress reduced macronutrient and Zn concentrations, as well as the total carbohydrate concentration, and increased peroxidase (POD) activity and chlorophyll fluorescence in the leaves of the 3 C. limon cultivars studied; five mM KNO3 application alleviated the harmful effect of salt stress on leaf total carbohydrate concentration and leaf N and K concentrations. Sucrose was dramatically reduced in all the three genotypes studied, while leaf fructose concentration was significantly increased in Nouvel Nouvel Nouvel Athos and Maglini under salt stress. Leaf proline concentration of Maglini was significantly decreased by the high NaCl concentration, while Nouvel Athos and Lisbon had high proline concentration in their leaves. In conclusion, from the significantly decreased levels of proline for Maglini, together with the greatest reduction of the ratio Fv/Fm and the least enhancement of POD activity-compared to the other two cultivars-it can be concluded that Maglini was more susceptible to salinity, and should not be preferred for cultivation under NaCl stress. Finally, rich KNO3 application alleviated the harmful effect of NaCl stress, thus it is highly recommended for use by the growers in areas with salt problems. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Two-stage gas-phase bioreactor for the combined removal of hydrogen sulphide, methanol and alpha-pinene.

PubMed

Rene, Eldon R; Jin, Yaomin; Veiga, María C; Kennes, Christian

2009-11-01

Biological treatment systems have emerged as cost-effective and eco-friendly techniques for treating waste gases from process industries at moderately high gas flow rates and low pollutant concentrations. In this study, we have assessed the performance of a two-stage bioreactor, namely a biotrickling filter packed with pall rings (BTF, 1st stage) and a perlite + pall ring mixed biofilter (BF, 2nd stage) operated in series, for handling a complex mixture of hydrogen sulphide (H2S), methanol (CH3OH) and alpha-pinene (C10H16). It has been reported that the presence of H2S can reduce the biofiltration efficiency of volatile organic compounds (VOCs) when both are present in the gas mixture. Hydrogen sulphide and methanol were removed in the first stage BTF, previously inoculated with H2S-adapted populations and a culture containing Candida boidinii, an acid-tolerant yeast, whereas, in the second stage, alpha-pinene was removed predominantly by the fungus Ophiostoma stenoceras. Experiments were conducted in five different phases, corresponding to inlet loading rates varying between 2.1 and 93.5 g m(-3) h(-1) for H2S, 55.3 and 1260.2 g m(-3) h(-1) for methanol, and 2.8 and 161.1 g m(-3) h(-1) for alpha-pinene. Empty bed residence times were varied between 83.4 and 10 s in the first stage and 146.4 and 17.6 s in the second stage. The BTF, working at a pH as low as 2.7 as a result of H2S degradation, removed most of the H2S and methanol but only very little alpha-pinene. On the other hand, the BF, at a pH around 6.0, removed the rest of the H2S, the non-degraded methanol and most of the alpha-pinene vapours. Attempts were originally made to remove the three pollutants in a single acidophilic bioreactor, but the Ophiostoma strain was hardly active at pH <4. The maximum elimination capacities (ECs) reached by the two-stage bioreactor for individual pollutants were 894.4 g m(-3) h(-1) for methanol, 45.1 g m(-3) h(-1) for H2S and 138.1 g m(-3) h(-1) for alpha-pinene. The results from this study showed the potential effectiveness of a two-stage bioreactor for treating H2S together with two hydrophilic and hydrophobic VOCs that are typically emitted from wood industries.

Mitigation of Methane and Odor using a Pilot-Scale Engineered Biocover at a Landfill, South Korea

NASA Astrophysics Data System (ADS)

Bomin, K.; O, G. C.; Ryu, H. W.; Jeon, J. M.; Cho, K. S.

2016-12-01

Landfill is an important anthropogenic source of methane (CH4) and odorous gases. In South Korea, 37% (0.5 Tg/y) of annual anthropogenic CH4 emissions come from landfills, which represent the third largest source of anthropogenic CH4 emissions. Moreover, civil complaints on landfill odor have been gradually increased. Biocovers have been demonstrated as promising solutions to mitigate CH4 and odors from landfills. The pilot-scale biocover (10 m in length x 5 m in width x 1 m in depth) was constructed at a landfill, Gwangyang, South Korea. The mixture of soil and perlite was used as packing materials, and EG microbial agent was used as an inoculum source. Methane removal efficiencies were 21% 72% from Feburary to May. Based on the dilution-to-threshold ratios derived by the air dilution sensory test, the removal efficiencies for complex odor were ranged from 95% to 99%. The packing materials of biocover were sampled from each of the following depth intervals: 0-15 cm, 15-30 cm, and 30-50 cm, and CH4 and DMS degradation rates were measured in serum bottles experiment. CH4 and DMS average degradation rates were the fastest in the 15-30 cm depth. Average degradation rates of CH4 and DMS in the 15-30 cm depth were 208±2.68 and 82±3.04 μg·g dry soil-1·h-1, respectively. Specific degradation rate were calculated excluding the lag time. CH4 specific degradation rate was the fastest in the 0-15 cm depth (329±14.45 μg·g dry soil-1·h-1), while DMS specific degradation rate was the fastest in the 30-50 cm depth (106±6.93 μg·g dry soil-1·h-1). The filling materials of biocover were sampled during winter, spring and summer. And three samples were examined bacterial communities by 16S rRNA pyrosequencing analysis. In order to clarify the relationship between the community structures and CH4/odor concentration, network analysis using extended local similarity analysis (eLSA) was also conducted. According to a phylogenic analysis, Methylobacter (40.4 42.1%) and Flavobacterium (20.2 38.2%) were the most prevalent species in the pilot-scale biocover. Methylobacter (Methanotrophics of Type I) are responsible for methane oxidation and can be identified in the biocover.

Mineral Resources of the Black Mountains North and Burns Spring Wilderness Study Areas, Mohave County, Arizona

USGS Publications Warehouse

Conrad, James E.; Hill, Randall H.; Jachens, Robert C.; Neubert, John T.

1990-01-01

At the request of the U.S. Bureau of Land Management, approximately 19,300 acres of the Black Mountains North Wilderness Study Area (AZ-020-009) and 23,310 acres of the Burns Spring Wilderness Study Area (AZ-02D-010) were evaluated for mineral resources and mineral resource potential. In this report, the area studied is referred to, collectively or individually, as the 'wilderness study area' or simply 'the study area'; any reference to the Black Mountains North or Burns Spring Wilderness Study Areas refers only to that part of the wilderness study area for which a mineral survey was requested by the U.S. Bureau of Land Management. The study area is located in western Arizona, about 30 mi northwest of Kingman. There are no identified resources in the study area. An area surrounding the Portland mine and including the southern part of the Black Mountains North Wilderness Study Area and the extreme northwestern part of the Burns Spring Wilderness Study Area has high resource potential for gold and moderate resource potential for silver, lead, and mercury. The area surrounding this and including much of the northern part of the Burns Spring Wilderness Study Area has moderate potential for gold, silver, and lead. The northeastern corner of the Black Mountains North Wilderness Study Area has moderate potential for gold and low potential for silver, copper, and molybdenum resources. The central part, including the narrow strip of land just west of the central part, of the Black Mountains North Wilderness Study Area and the southern and extreme eastern parts of the Burns Spring Wilderness Study Area have low resource potential for gold. The central and southern parts of the Black Mountains North Wilderness Study Area and all but the southwestern part of the Burns Spring Wilderness Study Area have moderate resource potential for perlite. Moderate resource potential for zeolites is assigned to a large area around the Portland mine that includes parts of both study areas, to a narrow strip of land just west of the central part of the Black Mountains North Wilderness Study Area, and to all but the southwest corner of the Burns Spring Wilderness Study Area. There is no potential for oil and gas in either study area. Sand and gravel are present in both study areas, but abundant quantities of these resources are available closer to existing markets.

Dacite Melt at the Puna Geothermal Venture Wellfield, Big Island of Hawaii

NASA Astrophysics Data System (ADS)

Teplow, W. J.; Marsh, B. D.; Hulen, J.; Spielman, P.; Kaleikini, M.; Fitch, D. C.; Rickard, W.

2008-12-01

A dacite melt was encountered during routine commercial drilling operations of injection well KS-13 at the Puna Geothermal Venture wellfield, Big Island of Hawaii. The KS-13 drill hole, drilled in 2005, is located along a segment of the Kilauea Lower East Rift Zone which erupted basalt flows from rift-parallel fissures in 1955. During the drilling of KS-13 a 75-meter interval of microdiorite containing brown glass inclusions was penetrated at a depth of 2415 m. At a depth of 2488 m a melt of dacitic composition was encountered. The melt flowed up the wellbore and was repeatedly redrilled over a depth interval of ~8 m, producing several kilograms of clear, colorless vitric cuttings at the surface. The drill bit, when recovered at the surface, was missing several carbide insert teeth. Presumably the inserts were plucked cleanly from their sintered cone sockets due to differential thermal expansion under extreme heat conditions. The dacitic glass cuttings have a perlitic texture, a silica content of 67 wgt.%, are enriched in alkalis and nearly devoid of mafic minerals with the exception of rare pyroxene phenocrysts and minor euhedral to amorphous magnetite. The melt zone is overlain by an interval of strong greenschist facies metamorphism in basaltic and dioritic dike rock. The occurrence of an anhydrous dacite melt indicates a rock temperature of approximately 1050° (1922°F) and sufficient residence time of underlying basaltic magma to generate a significant volume of differentiated material. The dacite, with an inferred temperature of 1050 °C, is separated by 526 m of rock from the deepest overlying permeable zone in KS-13 at a temperature of 356 °C. The thermal gradient through this impermeable rock section is ~700°C/526 m = 1.331 °C/m. The calculated conductive heat flux from the magma upward into the deepest zone of hydrothermal circulation is given by k×(dT/dZ)=2.9 × 1.33 = 3.83 W/m2 = 3830 mW/m2 (thermal conductivity k=2.9 W m-1 °C-1 for basalt). This heat flux is an order of magnitude greater than the average of 270-290 mW/ m2 typical for the mid-ocean ridges. The high heat flux is sufficient to power the overlying commercial geothermal wellfield which has been producing 28 MW of net electrical power continuously since 1993.

The role of residual (undegassed) and environmental waters in pyroclastic volcanic glass in nature and experiments (Invited)

NASA Astrophysics Data System (ADS)

Bindeman, I. N.; Seligman, A. N.; Nolan, G. S.; Lundstrom, C.; Martin, E.; Lowenstern, J. B.; Palandri, J. L.

2013-12-01

The advent and calibration of the Thermal Combustion Element Analyzer (TCEA) continuous flow system coupled with the large-radius mass spectrometer, at the University of Oregon, permits precise (×0.02 wt.% H2O, ×1-3‰ D/H) measurements in 1-10 mg of volcanic glass (0.1 wt.% H2O requires ~10 mg glass). This is a 10-100 time reduction in sample size over previous methods, which permits the targeting of small amounts of the freshest concentrate. In combination with the FTIR, we use the TCEA to research problems involving the mechanisms and timescales of volcanic ash hydration on both natural and laboratory timescales using isotopically-labeled water, D/H-H2O pathways of volcanic degassing, water content and D/H in recently erupted volcanic ash, and the mechanisms of tephra-hydration by isotopically-distinct rain and glacial meltwaters. The talk will review new results: 1) Water content determined by FTIR (OH and H2O) and TCEA give excellent correspondence for basaltic and rhyolitic glasses, including FTIR measurements for irregular ash particles mixed in equal proportion with KBr and molded into pellets. 2) Nominally-anhydrous (<0.1-0.2 wt.% water) volcanic ash actually contains appreciable 'undegassed', variably low-δD water (up to ~0.6 wt.%). 3) Long term exposure experiments involving ash placed in isotopically-labeled water does not lead to water uptake or δ18O exchange at 20, 40, or 70 °C over two years of laboratory exposure, but does involve up to 15% deuterium exchange relative to the full exchange equilibria. This provides a word of caution in using δD values of ash as a paleoenvironmental tool. 4) Degassing of environmentally-hydrated ash (4 wt.% water) leads to neglegeable δD exchange, signifying nearly zero-fractionation upon loss of predominantly H2Omol water. 5) Glacial vs. intergacial water can be recognized in hydrated glasses. 6) Subaqueous perlites from Yellowstone have an onion-skin distribution of water with water-poor cores, as determined by the scanning FTIR technique. 7) Thermal diffusion experiments achieve up to a 144‰ range in δD across a 300-600°C temperature change; this has implications for explaining natural variations in δD in high temperature environments due to high diffusivity of hydrogen. 8) We report results of δ18O in extracted water in glass and discuss isotopic offsets due to incomplete oxygen extraction from OH groups. 9) We apply these methods to submarine glasses, and degassing tephra products of the same eruption.

Assessment of the TNT- and AMPA-Induced Changes in Vegetation Morphology and Bio-physical Properties

NASA Astrophysics Data System (ADS)

Campbell, P. K.; Middleton, E.; Corp, L.

2009-12-01

Currently, there is no satisfactory method for locating unexploded ordinance or to mitigate the environmental impacts of leaked TNT. Non-exploded TNT-containing land mines deployed during military training exercises eventually leak TNT into the soils, where it is partially degraded into nitrate and toluene, a carcinogen. Environmental stresses alter plant physiology, affecting photosynthesis as well as the production of protective chemicals such as phenolic compounds which fluoresce in the blue/green spectrum. Changes in the fluorescence and reflectance spectral signatures of vegetation occur concurrently with the changes in plant vigor and chemical constituents. Thus, monitoring of vegetation vigor based on fluorescence and reflectance measurements could provide the means for detecting contamination from trinitrotoluene (TNT), a common compound contained in land mines. The goal of this study was to evaluate the capability of fluorescence sensing systems to remotely detect the presence of TNT-related compounds sequestered in vegetation growing on TNT contaminated soils. Using instrumentation and methodologies that utilize reflectance and actively induced fluorescence associated with “stead-state” emissions, we conducted experiments on four experimental species - two of which have the C4 photosynthetic pathway and two of which have the more common C3 pathway. The experimental plants were grown outdoors in 2 gallon pots in a 75:25 mixture of white quartz sand and perlite, with planted pots placed in larger pots to retain water and TNT solution added. Plants were randomly assigned to treatments for twice weekly applications of 0, 10, and 20 μl/l TNT solutions [doses ~30 μl/l are toxic] and watered daily as necessary. Our findings, using ChlF spectra, indicate statistically significant differences between TNT treated and control samples in the blue and green regions. Maximum treatment separation was achieved using 280Ex and measuring emissions in the blue. Experimental variation (e.g. Std. Errors) increased with higher TNT concentrations. Foliar ChlF images acquired in the blue, green, red and far-red bands displayed very clearly the large (obvious) differences in ChlF intensity, despite of the variation within treatments. The differences in reflectance (R, %) magnitude allowed the separation of treated from control plants using high spectral resolution R data (3-5 nm). While the relatively large R differences occur in the green and red/red-edge regions, the spectral sensitivity to the TNT treatments is maximal in the 650-750 nm region. Narrow band ratios/indices utilizing the spectral changes in the 650-750 nm region have potential as indicator of the TNT effects on plants. Broad-band indices (> 10nm) did not provide discrimination potential, however a number of high spectral resolution indices (~3nm) were able to separate control from TNT treated plants. While the indices providing best separation capability (PRI1, derivative indices, etc.) were all well related to pigment content, they were also strongly associated with either rate of photosynthesis (Amax) or foliar chemistry (C:N ratio).

Preliminary Findings of Petrology and Geochemistry of The Aladaǧ Volcanic System and Surrounding Areas (Kars, Turkey)

NASA Astrophysics Data System (ADS)

Duru, Olgun; Keskin, Mehmet

2017-04-01

Between the towns of Sarıkamış and Kaǧızman, NE Turkey, a medium-sized strato-volcano with satellite cones and domes on its slopes unconformably overlies the Erzurum-Kars Volcanic Plateau (EKVP) with a subhorizontal contact. It is called the Aladaǧ volcanic system (AVS). Dating results indicate that the AVS is Pliocene in age. The EKVP is known to be formed by a widespread volcanism between Middle Miocene to Pliocene. The young volcanism in E Turkey including the study area is linked to a collision between the Eurasia and Arabian continents, started almost 15 Ma ago. The EKVP lies over 2000 m above the sea level, and is deeply cut by the river Aras. On the slopes of the valley, one of the best volcano-stratigraphic transects of Eastern Anatolia, almost half a km thick, is exposed. That transect is composed of aphyric andesites-dacites, ignimbrites, tuffs, perlite and obsidian bands. Pyroclastic fall and surge-related pumice deposits are also widespread. Top of the plateau is composed of the andesitic to basaltic andesitic lavas containing plagioclase (Plg) and ortho/clino pyroxene (Opx/Cpx) phenocrysts set in glassy groundmass. In the northwest of the study area, an eroded stratovolcano, probably coeval with the plateau sequence is situated. It also consists of high-silica rhyolites and pyroclastic equivalents. The AVS is composed basically of intermediate lavas. The largest volcanic edifice of the Aladaǧ volcanic system, namely the Greater Aladaǧ stratovolcano reaches up to 3000 m height and includes a horseshoe shaped crater open to the North. Small volcanic cones and domes sit on the flanks of the Greater Aladaǧ volcano. The Aladaǧ lavas are divided into four sub-groups on the basis of their stratigraphic positions, mineral assemblages and textural properties. (1) The oldest products of the Greater Aladaǧ stratovolcano are andesitic and dasitic lavas. They directly sit on the EKVP. These are Plg and Opx/Cpx bearing lavas with porphric, vitrophyric, and hyalopilitic textures. (2) The second stage lavas, covering large areas are andesitic to dacitic in composition, consisting of Plg and Px and amphibole (Amp) xenocrysts. (3) On the northwestern flank of the Gretater Aladaǧ, about twenty lava flows are exposed. These aphyric lavas consist of Plg and Opx. (4) The aphyric lavas of the Lesser Aladaǧ, in the northwest of the Greater Aladaǧ volcano, are basaltic andesitic in composition. In the northeast of the study area, Upper Pliocene lavas exposed on the southern edge of the Kars plateau are the youngest volcanic units which are basaltic in composition displaying porphyritic textures in the study area. They are composed of plagioclase and clinopyroxene phenocrysts. Volcanic products in the study area are calc-alkaline in character with a clear subduction signature. They show textures characteristic for magma mixing processes indicating periodic replenishment of magma chamber by primitive basaltic magmas. Our assimilation models indicate that AFC was an important process for the evolved lavas. However, AFC remained negligible during the magma chamber evolution of the basic volcanic units.

Geology and ground water in Napa and Sonoma Valleys, Napa and Sonoma Counties, California

USGS Publications Warehouse

Kunkel, Fred; Upson, Joseph Edwin

1960-01-01

Napa and Sonoma Valleys are adjacent alluvium-filled valleys about 40 miles northeast of San Francisco. They occupy alined and structurally controlled depressions in the northern Coast Ranges physiographic province and drain south into San Pablo Bay. The valleys are surrounded and underlain by unconsolidated marine and continental sediments and volcanic rocks of Pliocene and Pleistocene age, which are water bearing in large part and together make up relatively extensive ground-water basins. Napa Valley, the eastern valley, is the larger and has a valley-floor area of about 85 square miles. Sonoma Valley has a valley-floor area of about 35 square miles; in addition, about 10 square miles is unreclaimed tidal marsh. The rock units of Napa and Sonoma Valleys are divided into four classes on the basis of their distribution and relative capacity to yield water: (a) Consolidated virtually non-water-bearing chiefly sedimentary (some metamorphic) rocks that range in age from Jurassic ( ?) to Pliocene; (b) marine shale and sand of the Petaluma formation (Pliocene) and the Merced formation (Pliocene and Pleistocene) that do not crop out within Napa or Sonoma Valleys but perhaps are penetrated by some deep wells drilled in Sonoma Valley; (c) Sonoma volcanics of Pliocene age, parts of which are non-water-bearing and parts of which locally yield large quantities of water; and (d) unconsolidated alluvial deposits mainly of Quaternary age. The deposits of classes (c) and (d) contain the most important aquifers in the area. Most of the water used in these valleys is pumped from wells in the younger and older alluvium in the Huichica and Glen Ellen formations. and in the Sonoma volcanics. The principal aquifers are the younger and older alluvium. but appreciable quantities of water are pumped locally from the Sonoma volcanics. The Huichica and Glen Ellen formations yield water in small quantities and at most places supply water only for limited domestic uses. The younger alluvium COIM3ists of interbedded deposits of unconsolidated gravel. sand, silt. and. locally, peat. These deposits underlie the flood plains and channels of the Napa River. Sonoma Creek, and their tributaries, low alluvial fans or plains graded to these streams. and the tidal marshlands. The older alluvium of Napa and Sonoma Valleys is composed of lenticular deposits of unconsolidated and poorly sorted clay, silt. sand. and gravel. Where exposed, claypan or hardpan soil is characteristically developed at the surface. The Huichica formation is composed of deformed continental beds consisting mostly of yellow silt with some interbedded lenses of silt and gravel, and silt and boulders. At the base are beds of redeposited volcanic material, silt, clay, and lenses of coarse gravel and boulders. The Glen Ellen fcrmation consists of alluvial clay, silt, sand, and gravel in clearly stratified but generally lenticular beds. The Sonoma volcanics constitute a thick and highly variate series of continental volcanic rocks, including andesite, basalt, and minor rhyolite flows and interbedded coarse- to fine-grained pyroclastic tuff and breccia, redeposited tuff and pumice, and diatomaceous mud, silt, and sand. A prominent body of rhyolite flows and tuff with some obsidian and perlitic glass, called the St. Helena rhyolite member, occurs in the upper part. Estimated ground-water pumpage for all uses in the year 1949-50 was about 5,600 acre-feet in Napa Valley and about 2,400 acre-feet in Sonoma Valley. Of this quantity the amounts pumped for irrigation were about 2,900 and 1,900 acre-feet, respectively. Water levels in wells in the central parts of the valleys range from a few feet above the land surface to about 50 feet below, with an average of about 25 feet. The quality of the water in most wells is satisfactory for domestic use and irrigation. Locally at the southern end of the valley some contamination of the native waters is caused by the movement of salty wate

The volcanic-sedimentary sequence of the Lousal deposit, Iberian Pyrite Belt (Portugal)

NASA Astrophysics Data System (ADS)

Rosa, Carlos; Rosa, Diogo; Matos, Joao; Relvas, Jorge

2010-05-01

The Iberian Pyrite Belt (IPB) is a massive sulfide province that is located in the south of Portugal and Spain, and hosts more than 90 massive sulfide deposits that amount to more than 1850 million metric tonnes of sulfide ore (Tornos, 2006). The ore deposits size, vary from ~1Mt to >100Mt (e.g. Neves Corvo and Aljustrel in Portugal, and Rio Tinto and Tharsis in Spain). The ore deposits are hosted by a submarine sedimentary and volcanic, felsic dominated, succession that constitutes the Upper Devonian to Lower Carboniferous Volcanic and Sedimentary Complex (VSC). The VSC ranges in thickness from approximately 600 to 1300 m (Tornos 2006). The VSC overlies the Phyllite-Quartzite Group (PQ) (Upper Devonian, base unknown) and is overlain by the Baixo Alentejo Flysch Group (Lower to Upper Carboniferous). The Lousal massive sulfide deposit is located in the western part of the IPB and occurs mostly interbedded with black mudstone. The VSC sequence at Lousal mine consists of a mudstone and quartzite sequence (PQ Group) in the lower part of the succession, over which a thick sequence of rhyolitic lavas (>300 m) occurs. Above the rhyolitic lavas there is a thick sequence of black and grey mudstone that hosts the massive sulfide ore bodies, and a rhyolitic sill. The upper part of the VSC sequence consists of a thick mudstone interval that hosts two thick basaltic units, locally with pillows. The rhyolites have small coherent cores, locally with flow bands, that grade to surrounding massive clastic intervals, with large lateral extent. The clasts show jigsaw-fit arrangement in many places and have planar or curviplanar margins and locally are perlitic at the margin. The top contact of these units is in most locations not exposed, which makes difficult to interpret the mode of emplacement. However, the thick clastic intervals, above described, are in accordance with quenching of volcanic glass with abundant water and therefore indicate that quenching of the rhyolites was the dominant fragmentation mechanism. Unlike many locations of the IPB, fiamme-rich pyroclastic units were not identified at Lousal. The ore deposits occur in close proximity with this volcanic centre that may have driven hydrothermal circulation that led to ore formation. The volcanic rocks show intense chloritic alteration, indicating that the mineralizing event occurred after most of the rhyolitic units have emplaced. The massive sulfides show abundant sedimentary structures which is not typical in the massive sulfide deposits of the IPB. The Lousal 50 Mt massive sulfide deposit consists of at least 11 ore bodies and was exploited until 1988 mainly for pyrite. The ores mined averaged 0.7% Cu, 0.8%Pb e 1.4%Zn (Strauss, 1971). These relatively low base metal grades led to an evaluation of the contents and distribution of high-tech element in the ore bodies, which would improve the economic viability of mining the deposit. This evaluation is currently focusing on the distribution and mineralogy of selenium, as ores mined in the past were known to be rich in this element. This work benefits from research projects INCA (PTDC/CTE-GIN/67027/2006; Characterization of crucial mineral resources for the development of renewable energy technologies: The Iberian Pyrite Belt ores as a source of indium and other high-technology elements) and project ARCHYMEDES II (POCTI/CTA/45873/2002), both funded by the Fundação para a Ciência e Tecnologia. REFERENCES Strauss, G.K., 1970. Sobre la geologia de la provincia piritifera del Suroeste de la Peninsula Iberica y sus yacimientos, en especial sobre la mina de pirita de Lousal (Portugal): Memoria del IGME 77, 1-266. Tornos, F., 2006. Environment of formation and styles of volcanogenic massive sulfides: The Iberian Pyrite Belt. Ore Geology Reviews 28, 259-307.

Metallogeny of the Great Basin: crustal evolution, fluid flow, and ore deposits

USGS Publications Warehouse

Hofstra, Albert H.; Wallace, Alan R.

2006-01-01

The Great Basin physiographic province in the Western United States contains a diverse assortment of world-class ore deposits. It currently (2006) is the world's second leading producer of gold, contains large silver and base metal (Cu, Zn, Pb, Mo, W) deposits, a variety of other important metallic (Fe, Ni, Be, REE's, Hg, PGE) and industrial mineral (diatomite, barite, perlite, kaolinite, gallium) resources, as well as petroleum and geothermal energy resources. Ore deposits are most numerous and largest in size in linear mineral belts with complex geology. U.S. Geological Survey (USGS) scientists are in the final year of a research project initiated in the fall of 2001 to increase understanding of relations between crustal evolution, fluid flow, and ore deposits in the Great Basin. Because of its substantial past and current mineral production, this region has been the focus of numerous investigations over the past century and is the site of ongoing research by industry, academia, and state agencies. A variety of geoinformatic tools was used to organize, reinterpret, and display, in space and time, the large amounts of geologic, geophysical, geochemical, and hydrologic information deemed pertinent to this problem. This information, in combination with concentrated research on (1) critical aspects of the geologic history, (2) an area in northern Nevada that encompasses the major mineral belts, and (3) important mining districts and deposits, is producing new insights about the interplay between key tectonic events, hydrothermal fluid flow, and ore genesis in mineral belts. The results suggest that the Archean to Holocene history of the Great Basin was punctuated by several tectonic events that caused fluids of different origins (sea water, basinal brine, meteoric water, metamorphic water, magmatic water) to move through the crust. Basement faults reactivated during these events localized deformation, sedimentation, magmatism, and hydrothermal fluid flow in overlying rocks to form mineral belts that contain ore deposits of different types and ages that are locally superimposed (demonstrating inheritance). Fluid flow in these systems also was influenced by the distribution of permeable lithologies and paleotopographic highs and lows. Hydrothermal fluids evolved from their initial chemistries towards compositions that reflect the f O2 and f S2 buffering capacity of, and the ligands and metals present in, the rocks (?older mineralization) through which they moved. In northern Nevada, where gold deposits are relatively common, carbonaceous, pyritic strata buffered fluids of diverse origins to H2S-rich compositions so they could transport gold repeatedly over Paleozoic-Cenozoic time (convergent evolution). Ore formed where metal-laden fluids encountered effective physicochemical traps. Maps of Neogene basin fill and erosion surfaces identify areas where preexisting ore deposits have been progressively exposed or concealed. Comparisons with analogous terrains and deposit types in other parts of the world provide global context. The initial findings and some of the databases, geologic maps, sections, reconstructions, hydrogeologic models, topical syntheses, regional overviews, short courses, field guides, and deposit comparisons produced by project staff and associated managers, contractors, and collaborators have been presented in numerous abstracts, symposia, USGS publications, and professional journals over the last 5 years (see the extensive bibliography). Notable among these was the 2005 Geological Society of Nevada symposium in Reno, Nevada, and the 2005 Geological Society of America annual meeting in Salt Lake City, Utah, where project results were presented to audiences from around the nation and world. The final results of the project will be submitted for publication in 2007 to appropriate USGS and professional journals. A special issue of GEOSPHERE, scheduled for publication in 2007, will be devoted to the results o

Substructure and strengthening of heavily deformed single and two-phase metallic materials

NASA Astrophysics Data System (ADS)

Gil Sevillano, J.

1991-06-01

Work hardening of single-phase crystalline materials (and to some extent, coarse two-phase and dispersion hardened materials too) at low temperatures results from the competition of two dynamic processes: dislocation accumulation, during the long-range gliding of mobile dislocations and dynamic recovery, involving local rearrangements and length annihilation from mobile and stored dislocation interactions. Its complete understanding would be very useful for designing materials with maximized strength after heavy cold work. However, modelling of the strain-induced evolution of the dislocation substructure, an essential ingredient of any work hardening theory, is still far from satisfactory. On the other hand, some heavily deformed ductile two-phase in situ composites are only second to whiskers among the strongest metallic materials. At first sight, the main obstacle geometry for dislocation glide in lamellar or multifilamentary in situ composites being clear-cut, it can be thought that their strength and work hardening are completely understood. However, this is not so and several schools of thought propose different interpretations for the exaggerated departure of the stress-strain curves of in situ composites from the rule-of-mixtures curves built from those of their bulk components. This paper aims to discuss such interpretations. The composite Cu-Nb is taken as model material owing to the extensive and detailed mechanical and microstructural data available in the literature, including different deformation temperatures and two different strain paths. Fine pearlite Fe-Fe3C is the other obvious reference. Le durcissement par déformation des matériaux cristallins monophasés (et, dans une certaine mesure, des matériaux biphasés à grande dimension de phases, et des matériaux renforcés par une phase dispersée) à basse température résulte d'une compétition entre deux processus dynamiques: l'accumulation de dislocations pendant le glissement des dislocations sur de longues distances, et la restauration dynamique, comprenant des réarrangements locaux et des annihilations par réaction entre dislocations mobiles et accumulées. La compréhension complète de ces mécanismes serait très utile à la conception de matériaux de résistance optimisée par écrouissage. Cependant, la modélisation de l'évolution de la sous structure induite par déformation, qui est un ingrédient essentiel de toute théorie du durcissement, est encore loin d'être satisfaisante. Par ailleurs, certains composites in situ biphasés écrouis viennent juste après les whiskers parmi les matériaux métalliques les plus résistants. A première vue, le principal obstacle géométrique au glissement des dislocations dans les composites in situ lamellaires ou à fibres étant évident, on peut penser que leur résistance et leur durcissement sont parfaitement compris. Cependant, il n'en est rien et plusieurs écoles de pensée proposent diverses interprétations pour les écarts exagérés des courbes contrainte-déformation des composites in situ, par rapport aux courbes obtenues par la loi des mélanges. Le but de cet article est de discuter ces interprétations. Le composite Cu-Nb est choisi comme modèle, à cause de l'abondance des données mécaniques et microstructurales disponibles dans la littérature, pour diverses températures et chemins de déformation. La perlite fine Fe-Fe3C est l'autre référence évidente.

Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska; dissolved oxygen and Escherichia coli bacteria in streams during low flow, July 1988 through July 1989

USGS Publications Warehouse

Pope, L.M.

1995-01-01

The 15,300-square-mile lower Kansas River Basin in Kansas and Nebraska was investigated, as one of the pilot study units of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program, to address a variety of water-quality issues. This report describes sanitary quality of streams as defined by concentrations of dissolved oxygen (DO) and densities of a fecal-indicator bacterium, Escherichia coli (E. coli). Sixty-one surface-water sampling sites were chosen for this investigation. Synoptic surveys were conducted in July 1988, November 1988, March 1989, and May 1989 to define the concentrations and diel and seasonal variability in concentrations of DO. Synoptic surveys were conducted in July 1988 and July 1989 to define densities of E. coli. Ancillary data included measurements of specific conductance, pH, water temperature. barometric pressure, and concentrations of nutrients, total organic carbon, chlorophyll, and suspended sediment. Surveys were conducted during stable-flow, dry-weather conditions. During the July 1988 synoptic survey for DO, emphasis was placed on the measurement of DO under maximum stress (high water temperature, low streamflow, and predawn conditions). Of 31 sites sampled just before dawn, 5 had DO concentrations less than the 5.0-milligrams-perliter, l-day minimum warmwater criterion for early life stages as established by the U.S. Environmental Protection Agency (USEPA), and 4 of these 5 sites had concentrations less than the 3.0-milligrams-per-liter criterion for all other life stages. For all four synoptic surveys, a total of 392 DO determinations were made, and 9 (2.3 percent) were less than water-quality criteria. Concentrations of DO less than water-quality criteria in the study unit are localized occurrences and do not reflect regional differences in DO. The most severe DO deficiencies are the result of discharges from wastewater-treatment plants into small tributary streams with inadequate assimilation capacity. Algal respiratory demand in combination with reduced physical reaeration associated with extreme low flow probably also contributes to temporary, localized deficiencies. Densities of E. coli were determined at 57 surface-water sampling sites during the syn- optic survey in July 1988. Results indicate large regional differences in E. coli densities within the study unit. Densities orE. coli in water at 19 sites in the Big Blue River subbasin, exclusive of the Little Blue River subbasin, ranged from 120 to 260,000 col/100 mL (colonies per 100 milliliters), with a median density of 2,400 col/100 mL. Densities at the 11 sites in the Little Blue River ranged from 100 to 30,000 col/100 mL, with a median density of 940 col/100 mL. Densities at the 27 sites in the Kansas River subbasin ranged from less than 1 to 1,000 col/100 mL, with a median density of 88 col/100 mL. Densities at 84 percent of the sites in the Big Blue River subbasin exceeded the USEPA E. coli criterion of 576 col/100 mL for infrequently used full-body contact recreation, and 53 percent exceeded the 2,000 cot/I00 mL fecal coliform criterion for uses other than full-body contact established by the Kansas Department of Health and Environment. Densities at 73 percent of the sites in the Little Blue River subbasin exceeded the 576 col/100 mL E. coli criterion, and 36 percent exceeded the 2,000 col/100 mL fecal coliform criterion. Densities at one of the sites in the Kansas River subbasin exceeded the 576 col/100 mL E. coli criterion, and none exceeded the 2,000 col/100 mL fecal-coliform criterion. The largest densities of E. coli in the study unit were the result of discharges from municipal wastewater-treatment plants; however, densities in the Big Blue and Little Blue River subbasins were generally larger than those in the Kansas River subbasin. These larger densities in the Big Blue and Little Blue River subbasins may have been the result of irrigation return flow from fields where manure was used as a soil

Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

David W. Mazyck; Angela Lindner; CY Wu, Rick Sheahan, Ashok Jain

2007-06-30

Forest products provide essential resources for human civilization, including energy and materials. In processing forest products, however, unwanted byproducts, such as volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) are generated. The goal of this study was to develop a cost effective and reliable air pollution control system to reduce VOC and HAP emissions from pulp, paper and paperboard mills and solid wood product facilities. Specifically, this work focused on the removal of VOCs and HAPs from high volume low concentration (HVLC) gases, particularly methanol since it is the largest HAP constituent in these gases. Three technologies were developedmore » and tested at the bench-scale: (1) A novel composite material of activated carbon coated with a photocatalyst titanium dioxide (TiO{sub 2}) (referred to as TiO{sub 2}-coated activated carbon or TiO{sub 2}/AC), (2) a novel silica gel impregnated with nanosized TiO{sub 2} (referred to as silica-titania composites or STC), and (3) biofiltration. A pilot-scale reactor was also fabricated and tested for methanol removal using the TiO{sub 2}/AC and STC. The technical feasibility of removing methanol with TiO{sub 2}/AC was studied using a composite synthesized via a spay desiccation method. The removal of methanol consists of two consecutive operation steps: removal of methanol using fixed-bed activated carbon adsorption and regeneration of spent activated carbon using in-situ photocatalytic oxidation. Regeneration using photocatalytic oxidation employed irradiation of the TiO{sub 2} catalyst with low-energy ultraviolet (UV) light. Results of this technical feasibility study showed that photocatalytic oxidation can be used to regenerate a spent TiO{sub 2}/AC adsorbent. A TiO{sub 2}/AC adsorbent was then developed using a dry impregnation method, which performed better than the TiO{sub 2}/AC synthesized using the spray desiccation method. The enhanced performance was likely a result of the better distribution of TiO2 particles on the activated carbon surface. A method for pore volume impregnation using microwave irradiation was also developed. A commercial microwave oven (800 W) was used as the microwave source. Under 2450 MHz microwave irradiation, TTIP was quickly hydrolyzed and anatase TiO2 was formed in a short time (< 20 minutes). Due to the volumetric heating and selective heating of microwave, the solvent and by-products were quickly removed which reduced energy consumption and processing time. Activated carbon and TiO{sub 2}/AC were also tested for the removal of hydrogen sulfide, which was chosen as the representative total reduced sulfur (TRS) species. The BioNuchar AC support itself was a good H{sub 2}S remover. After coating TiO{sub 2} by dry impregnation, H{sub 2}S removal efficiency of TiO{sub 2}/AC decreased compared with the virgin AC due to the change of surface pH. Under UV light irradiation, H{sub 2}S removal efficiency of TiO{sub 2}/AC composite doubled, and its sulfate conversion efficiency was higher than that of AC. The formation of sulfate is preferred since the sulfate can be removed from the composite by rising with water. A pilot-scale fluidized bed reactor was designed to test the efficiency of methanol oxidation with TiO{sub 2}/AC in the presence of UV light. TiO{sub 2}/AC was prepared using the spray desiccation method. The TiO{sub 2}/AC was pre-loaded with (1) methanol (equivalent to about 2%wt) and (2) methanol and water. When the TiO{sub 2}/AC loaded with methanol only was exposed to UV light for one hour in the reactor, most of the methanol remained in the carbon pores and, thus, was not oxidized. The TiO{sub 2}/AC loaded with methanol and water desorbed about 2/3 of the methanol from its pores during fluidization, however, only a small portion of this desorbed methanol was oxidized. A biofilter system employing biological activated carbon was developed for methanol removal. The biofilter contained a mixed packing with Westvaco BioNuchar granular activated carbon, perlite, Osmocote slow release ammonium nitrate pellets, and Agrasoke water crystals in a 4:2:1:1 ratio by volume. The biofilter was inoculated with a bacterial culture collected from a Florida pulp and paperboard plant. A non-inoculated biofilter column was also tested. Use of a biological inoculum enriched from biofilm in the pulp and paper process has the potential to enhance the performance of a GAC biofilter. During testing, packing material was removed from the inlet and oulet of the biofilters and analyzed for genetic diversity using molecular techniques. The biofilter inoculated with specifically-enhanced inoculum showed higher bacterial diversity for methylotrophs and all bacteria, as compared to a non-inoculated biofilter. Mixed methylotrophic cultures, selected as potential biofilter inocula, showed increased methanol removal with highest concentrations of nitrogen provided as nitrate.« less