Process for removing sulfur from coal

DOEpatents

Aida, T.; Squires, T.G.; Venier, C.G.

1983-08-11

A process is disclosed for the removal of divalent organic and inorganic sulfur compounds from coal and other carbonaceous material. A slurry of pulverized carbonaceous material is contacted with an electrophilic oxidant which selectively oxidizes the divalent organic and inorganic compounds to trivalent and tetravalent compounds. The carbonaceous material is then contacted with a molten caustic which dissolves the oxidized sulfur compounds away from the hydrocarbon matrix.

Investigations into the mechanism of material removal and surface modification at atomic scale on stainless steel using molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Ranjan, Prabhat; Balasubramaniam, R.; Jain, V. K.

2018-06-01

A molecular dynamics simulation (MDS) has been carried out to investigate the material removal phenomenon of chemo-mechanical magnetorheological finishing (CMMRF) process. To understand the role of chemical assisted mechanical abrasion in CMMRF process, material removal phenomenon is subdivided into three different stages. In the first stage, new atomic bonds viz. Fe-O-Si is created on the surface of the workpiece (stainless steel). The second stage deals with the rupture of parent bonds like Fe-Fe on the workpiece. In the final stage, removal of material from the surface in the form of dislodged debris (cluster of atoms) takes place. Effects of process parameters like abrasive particles, depth of penetration and initial surface condition on finishing force, potential energy (towards secondary phenomenon such as chemical instability of the finished surface) and material removal at atomic scale have been investigated. It was observed that the type of abrasive particle is one of the important parameters to produce atomically smooth surface. Experiments were also conducted as per the MDS to generate defect-free and sub-nanometre-level finished surface (Ra value better than 0.2 nm). The experimental results reasonably agree well with the simulation results.

Removal and Disposal of An Environmental Carcinogen: Asbestos

ERIC Educational Resources Information Center

Fodero, Severio D.

1977-01-01

This article details the removal and disposal of asbestos ceiling material in a Yale University building. The removal process utilized a water and wetting agent technique used by firefighters and the debris disposal was in a sanitary landfill, following federal regulations for the handling of hazardous materials. (MA)

Self-assembly modified-mushroom nanocomposite for rapid removal of hexavalent chromium from aqueous solution with bubbling fluidized bed.

PubMed

Xu, Fei; Liu, Xu; Chen, Yijiao; Zhang, Ke; Xu, Heng

2016-05-18

A self-assembled modified Pleurotus Cornucopiae material (SMPM) combined with improved Intermittent Bubbling Fluidized Bed (IBFB) was investigated to remove the hexavalent chromium ions in aqueous solution. After the modification, the powder-like raw material gradually self-assembled together to SMPM, which had crinkly porous structure, improved the Cr-accommodation ability in a sound manner. Optimized by Taguchi method, Cr(VI) removal efficiency was up to 75.91% and 48.01% for 100 mg/L and 500 mg/L initial concentration of Cr(VI), respectively. Results indicated that the metal removal was dependent on dosage of adsorbent, particle diameter and treatment time. The experimental data obtained from the biosorption process was successfully correlated with Freundlich isotherm model. Thermodynamic study indicated the endothermic nature of the process. The results confirmed that self-assembly modified Pleurotus Cornucopiae material could be applied for the removal of heavy metal from wastewater in continuous fluidized bed process.

Self-assembly modified-mushroom nanocomposite for rapid removal of hexavalent chromium from aqueous solution with bubbling fluidized bed

PubMed Central

Xu, Fei; Liu, Xu; Chen, Yijiao; Zhang, Ke; Xu, Heng

2016-01-01

A self-assembled modified Pleurotus Cornucopiae material (SMPM) combined with improved Intermittent Bubbling Fluidized Bed (IBFB) was investigated to remove the hexavalent chromium ions in aqueous solution. After the modification, the powder-like raw material gradually self-assembled together to SMPM, which had crinkly porous structure, improved the Cr-accommodation ability in a sound manner. Optimized by Taguchi method, Cr(VI) removal efficiency was up to 75.91% and 48.01% for 100 mg/L and 500 mg/L initial concentration of Cr(VI), respectively. Results indicated that the metal removal was dependent on dosage of adsorbent, particle diameter and treatment time. The experimental data obtained from the biosorption process was successfully correlated with Freundlich isotherm model. Thermodynamic study indicated the endothermic nature of the process. The results confirmed that self-assembly modified Pleurotus Cornucopiae material could be applied for the removal of heavy metal from wastewater in continuous fluidized bed process. PMID:27188258

Self-assembly modified-mushroom nanocomposite for rapid removal of hexavalent chromium from aqueous solution with bubbling fluidized bed

NASA Astrophysics Data System (ADS)

Xu, Fei; Liu, Xu; Chen, Yijiao; Zhang, Ke; Xu, Heng

2016-05-01

A self-assembled modified Pleurotus Cornucopiae material (SMPM) combined with improved Intermittent Bubbling Fluidized Bed (IBFB) was investigated to remove the hexavalent chromium ions in aqueous solution. After the modification, the powder-like raw material gradually self-assembled together to SMPM, which had crinkly porous structure, improved the Cr-accommodation ability in a sound manner. Optimized by Taguchi method, Cr(VI) removal efficiency was up to 75.91% and 48.01% for 100 mg/L and 500 mg/L initial concentration of Cr(VI), respectively. Results indicated that the metal removal was dependent on dosage of adsorbent, particle diameter and treatment time. The experimental data obtained from the biosorption process was successfully correlated with Freundlich isotherm model. Thermodynamic study indicated the endothermic nature of the process. The results confirmed that self-assembly modified Pleurotus Cornucopiae material could be applied for the removal of heavy metal from wastewater in continuous fluidized bed process.

Method of treating contaminated HEPA filter media in pulp process

DOEpatents

Hu, Jian S.; Argyle, Mark D.; Demmer, Ricky L.; Mondok, Emilio P.

2003-07-29

A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

Removal Rate Model for Magnetorheological Finishing of Glass

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

DeGroote, J.E.; Marino, A.E.; WIlson, J.P.

2007-11-14

Magnetorheological finishing (MRF) is a deterministic subaperture polishing process. The process uses a magntorheological (MR) fluid that consists of micrometer-sized, spherical, magnetic carbonyl iron (CI) particles, nonmagnetic polishing abrasives, water, and stabilizers. Material removal occurs when the CI and nonmagnetic polishing abrasives shear material off the surface being polished. We introduce a new MRF material removal rate model for glass. This model contains terms for the near surface mechanical properties of glass, drag force, polishing abrasive size and concentration, chemical durability of the glass, MR fluid pH, and the glass composition. We introduce quantitative chemical predictors for the first time,more » to the best of our knowledge, into an MRF removal rate model. We validate individual terms in our model separately and then combine all of the terms to show the whole MRF material removal model compared with experimental data. All of our experimental data were obtained using nanodiamond MR fluids and a set of six optical glasses.« less

Carbon wastewater treatment process

NASA Technical Reports Server (NTRS)

Humphrey, M. F.; Simmons, G. M.; Dowler, W. L.

1974-01-01

A new powdered-carbon treatment process is being developed for the elimination of the present problems, associated with the disposal of biologically active sewage waste solids, and with water reuse. This counter-current flow process produces an activated carbon, which is obtained from the pyrolysis of the sewage solids, and utilizes this material to remove the adulterating materials from the water. Additional advantages of the process are the elimination of odors, the removal of heavy metals, and the potential for energy conservation.

Magnetorheological finishing for removing surface and subsurface defects of fused silica optics

NASA Astrophysics Data System (ADS)

Catrin, Rodolphe; Neauport, Jerome; Taroux, Daniel; Cormont, Philippe; Maunier, Cedric; Lambert, Sebastien

2014-09-01

We investigate the capacity of magnetorheological finishing (MRF) process to remove surface and subsurface defects of fused silica optics. Polished samples with engineered surface and subsurface defects were manufactured and characterized. Uniform material removals were performed with a QED Q22-XE machine using different MRF process parameters in order to remove these defects. We provide evidence that whatever the MRF process parameters are, MRF is able to remove surface and subsurface defects. Moreover, we show that MRF induces a pollution of the glass interface similar to conventional polishing processes.

Relationship between influence function accuracy and polishing quality in magnetorheological finishing

NASA Astrophysics Data System (ADS)

Schinhaerl, Markus; Schneider, Florian; Rascher, Rolf; Vogt, Christian; Sperber, Peter

2010-10-01

Magnetorheological finishing is a typical commercial application of a computer-controlled polishing process in the manufacturing of precision optical surfaces. Precise knowledge of the material removal characteristic of the polishing tool (influence function) is essential for controlling the material removal on the workpiece surface by the dwell time method. Results from the testing series with magnetorheological finishing have shown that a deviation of only 5% between the actual material removal characteristic of the polishing tool and that represented by the influence function caused a considerable reduction in the polishing quality. The paper discusses reasons for inaccuracies in the influence function and the effects on the polishing quality. The generic results of this research serve for the development of improved polishing strategies, and may be used in alternative applications of computer-controlled polishing processes that quantify the material removal characteristic by influence functions.

Ablation of steel by microsecond pulse trains

NASA Astrophysics Data System (ADS)

Windeler, Matthew Karl Ross

Laser micromachining is an important material processing technique used in industry and medicine to produce parts with high precision. Control of the material removal process is imperative to obtain the desired part with minimal thermal damage to the surrounding material. Longer pulsed lasers, with pulse durations of milli- and microseconds, are used primarily for laser through-cutting and welding. In this work, a two-pulse sequence using microsecond pulse durations is demonstrated to achieve consistent material removal during percussion drilling when the delay between the pulses is properly defined. The light-matter interaction moves from a regime of surface morphology changes to melt and vapour ejection. Inline coherent imaging (ICI), a broadband, spatially-coherent imaging technique, is used to monitor the ablation process. The pulse parameter space is explored and the key regimes are determined. Material removal is observed when the pulse delay is on the order of the pulse duration. ICI is also used to directly observe the ablation process. Melt dynamics are characterized by monitoring surface changes during and after laser processing at several positions in and around the interaction region. Ablation is enhanced when the melt has time to flow back into the hole before the interaction with the second pulse begins. A phenomenological model is developed to understand the relationship between material removal and pulse delay. Based on melt refilling the interaction region, described by logistic growth, and heat loss, described by exponential decay, the model is fit to several datasets. The fit parameters reflect the pulse energies and durations used in the ablation experiments. For pulse durations of 50 us with pulse energies of 7.32 mJ +/- 0.09 mJ, the logisitic growth component of the model reaches half maximum after 8.3 mus +/- 1.1 us and the exponential decays with a rate of 64 mus +/- 15 us. The phenomenological model offers an interpretation of the material removal process.

Angular analysis of the cyclic impacting oscillations in a robotic grinding process

NASA Astrophysics Data System (ADS)

Rafieian, Farzad; Girardin, François; Liu, Zhaoheng; Thomas, Marc; Hazel, Bruce

2014-02-01

In a robotic machining process, a light-weight cutter or grinder is usually held by an articulated robot arm. Material removal is achieved by the rotating cutting tool while the robot end effector ensures that the tool follows a programmed trajectory in order to work on complex curved surfaces or to access hard-to-reach areas. One typical application of such process is maintenance and repair work on hydropower equipment. This paper presents an experimental study of the dynamic characteristics of material removal in robotic grinding, which is unlike conventional grinding due to the lower structural stiffness of the tool-holder robot. The objective of the study is to explore the cyclic nature of this mechanical operation to provide the basis for future development of better process control strategies. Grinding tasks that minimize the number of iterations to converge to the target surface can be better planned based on a good understanding and modeling of the cyclic material removal mechanism. A single degree of freedom dynamic analysis of the process suggests that material removal is performed through high-frequency impacts that mainly last for only a small fraction of the grinding disk rotation period. To detect these discrete cutting events in practice, a grinder is equipped with a rotary encoder. The encoder's signal is acquired through the angular sampling technique. A running cyclic synchronous average is applied to the speed signal to remove its non-cyclic events. The measured instantaneous rotational frequency clearly indicates the impacting nature of the process and captures the transient response excited by these cyclic impacts. The technique also locates the angular positions of cutting impacts in revolution cycles. It is thus possible to draw conclusions about the cyclic nature of dynamic changes in impact-cutting behavior when grinding with a flexible robot. The dynamics of the impacting regime and transient responses to impact-cutting excitations captured synchronously using the angular sampling technique provide feedback that can be used to regulate the material removal process. The experimental results also make it possible to correlate the energy required to remove a chip of metal through impacting with the measured drop in angular speed during grinding.

Method for Selective Cleaning of Mold Release from Composite Honeycomb Surfaces

NASA Technical Reports Server (NTRS)

Pugel, Diane

2011-01-01

Honeycomb structures are commonly employed as load- and force-bearing structures as they are structurally strong and lightweight. Manufacturing processes for heat-molded composite honeycomb structures commence with the placement of pre-impregnated composite layups over metal mandrels. To prevent permanent bonding between the composite layup and the metal mandrels, an agent, known as a mold release agent, is used. Mold release agents allow the molded composite material to be removed from mandrels after a heat-forming process. Without a specific removal process, mold release agents may continue to adhere to the surface of the composite material, thereby affecting the bonding of other materials that may come into contact with the composite surface in later stages of processing A constituent common to commercially available household cleaning agents is employed for the removal of mold release agents common to the manufacturing of heat-formed composite materials. The reliability of the solvent has been proven by the longevity and reliability of commercial household cleaners. At the time of this reporting, no one has attempted using constituent for this purpose. The material to be cleaned is immersed in the solution, vertically removed so that the solution is allowed to drain along cell walls and into a solvent bath, and then placed on a compressed airflow table for drying.

Process for removing mercury from aqueous solutions

DOEpatents

Googin, J.M.; Napier, J.M.; Makarewicz, M.A.; Meredith, P.F.

1985-03-04

A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

Process for removing mercury from aqueous solutions

DOEpatents

Googin, John M.; Napier, John M.; Makarewicz, Mark A.; Meredith, Paul F.

1986-01-01

A process for removing mercury from water to a level not greater than two parts per billion wherein an anion exchange material that is insoluble in water is contacted first with a sulfide containing compound and second with a compound containing a bivalent metal ion forming an insoluble metal sulfide. To this treated exchange material is contacted water containing mercury. The water containing not more than two parts per billion of mercury is separated from the exchange material.

Material Behavior At The Extreme Cutting Edge In Bandsawing

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

Sarwar, Mohammed; Haider, Julfikar; Persson, Martin

2011-01-17

In recent years, bandsawing has been widely accepted as a favourite option for metal cutting off operations where the accuracy of cut, good surface finish, low kerf loss, long tool life and high material removal rate are required. Material removal by multipoint cutting tools such as bandsaw is a complex mechanism owing to the geometry of the bandsaw tooth (e.g., limited gullet size, tooth setting etc.) and the layer of material removed or undeformed chip thickness or depth of cut (5 {mu}m-50 {mu}m) being smaller than or equal to the cutting edge radius (5 {mu}m-15 {mu}m). This situation can leadmore » to inefficient material removal in bandsawing. Most of the research work are concentrated on the mechanics of material removal by single point cutting tool such as lathe tool. However, such efforts are very limited in multipoint cutting tools such as in bandsaw. This paper presents the fundamental understanding of the material behaviour at the extreme cutting edge of bandsaw tooth, which would help in designing and manufacturing of blades with higher cutting performance and life. ''High Speed Photography'' has been carried out to analyse the material removal process at the extreme cutting edge of bandsaw tooth. Geometric model of chip formation mechanisms based on the evidences found during ''High Speed Photography'' and ''Quick Stop'' process is presented. Wear modes and mechanism in bimetal and carbide tipped bandsaw teeth are also presented.« less

Adsorption-regeneration by heterogeneous Fenton process using modified carbon and clay materials for removal of indigo blue.

PubMed

Almazán-Sánchez, Perla Tatiana; Solache-Ríos, Marcos J; Linares-Hernández, Ivonne; Martínez-Miranda, Verónica

2016-01-01

Indigo blue dye is mainly used in dyeing of denim clothes and its presence in water bodies could have adverse effects on the aquatic system; for this reason, the objective of this study was to promote the removal of indigo blue dye from aqueous solutions by iron and copper electrochemically modified clay and activated carbon and the saturated materials were regenerated by a Fenton-like process. Montmorillonite clay was modified at pH 2 and 7; activated carbon at pH 2 and pH of the system. The elemental X-ray dispersive spectroscopy analysis showed that the optimum pH for modification of montmorillonite with iron and copper was 7 and for activated carbon was 2. The dye used in this work was characterized by infrared. Unmodified and modified clay samples showed the highest removal efficiencies of the dye (90-100%) in the pH interval from 2 to 10 whereas the removal efficiencies decrease as pH increases for samples modified at pH 2. Unmodified clay and copper-modified activated carbon at pH 2 were the most efficient activated materials for the removal of the dye. The adsorption kinetics data of all materials were best adjusted to the pseudo-second-order model, indicating a chemisorption mechanism and the adsorption isotherms data showed that the materials have a heterogeneous surface. The iron-modified clay could be regenerated by a photo-Fenton-like process through four adsorption-regeneration cycles, with 90% removal efficiency.

Monoatomic layer removal mechanism in chemical mechanical polishing process: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Si, Lina; Guo, Dan; Luo, Jianbin; Lu, Xinchun

2010-03-01

Molecular dynamics simulations of nanoscratching processes were used to study the atomic-scale removal mechanism of single crystalline silicon in chemical mechanical polishing (CMP) process and particular attention was paid to the effect of scratching depth. The simulation results under a scratching depth of 1 nm showed that a thick layer of silicon material was removed by chip formation and an amorphous layer was formed on the silicon surface after nanoscratching. By contrast, the simulation results with a depth of 0.1 nm indicated that just one monoatomic layer of workpiece was removed and a well ordered crystalline surface was obtained, which is quite consistent with previous CMP experimental results. Therefore, monoatomic layer removal mechanism was presented, by which it is considered that during CMP process the material was removed by one monoatomic layer after another, and the mechanism could provide a reasonable understanding on how the high precision surface was obtained. Also, the effects of the silica particle size and scratching velocity on the removal mechanism were investigated; the wear regimes and interatomic forces between silica particle and workpiece were studied to account for the different removal mechanisms with indentation depths of 0.1 and 1 nm.

Robotic Water Blast Cleaner

NASA Technical Reports Server (NTRS)

Sharpe, M. H.; Roberts, M. L.; Hill, W. E.; Jackson, C. H.

1983-01-01

Water blasting system under development removes hard, dense, extraneous material from surfaces. High pressure pump forces water at supersonic speed through nozzle manipulated by robot. Impact of water blasts away unwanted material from workpiece rotated on air bearing turntable. Designed for removing thermal-protection material, system is adaptable to such industrial processes as cleaning iron or steel castings.

Estimating the Additional Greenhouse Gas Emissions in Korea: Focused on Demolition of Asbestos Containing Materials in Building

PubMed Central

Kim, Young-Chan; Hong, Won-Hwa; Zhang, Yuan-Long; Son, Byeung-Hun; Seo, Youn-Kyu; Choi, Jun-Ho

2016-01-01

When asbestos containing materials (ACM) must be removed from the building before demolition, additional greenhouse gas (GHG) emissions are generated. However, precedent studies have not considered the removal of ACM from the building. The present study aimed to develop a model for estimating GHG emissions created by the ACM removal processes, specifically the removal of asbestos cement slates (ACS). The second objective was to use the new model to predict the total GHG emission produced by ACM removal in the entire country of Korea. First, an input-equipment inventory was established for each step of the ACS removal process. Second, an energy consumption database for each equipment type was established. Third, the total GHG emission contributed by each step of the process was calculated. The GHG emissions generated from the 1,142,688 ACS-containing buildings in Korea was estimated to total 23,778 tonCO2eq to 132,141 tonCO2eq. This study was meaningful in that the emissions generated by ACS removal have not been studied before. Furthermore, the study deals with additional problems that can be triggered by the presence of asbestos in building materials. The method provided in this study is expected to contribute greatly to the calculation of GHG emissions caused by ACM worldwide. PMID:27626433

Application specific beam profiles: new surface and thin-film refinement processes using beam shaping technologies

NASA Astrophysics Data System (ADS)

Hauschild, Dirk

2017-02-01

Today, the use of laser photons for materials processing is a key technology in nearly all industries. Most of the applications use circular beam shapes with Gaussian intensity distribution that is given by the resonator of the laser or by the power delivery via optical fibre. These beam shapes can be typically used for material removal with cutting or drilling and for selective removal of material layers with ablation processes. In addition to the removal of materials, it is possible to modify and improve the material properties in case the dose of laser photons and the resulting light-material interaction addresses a defined window of energy and dwell-time. These process windows have typically dwell-times between µs and s because of using sintering, melting, thermal diffusion or photon induced chemical and physical reaction mechanisms. Using beam shaping technologies the laser beam profiles can be adapted to the material properties and time-temperature and the space-temperature envelopes can be modified to enable selective annealing or crystallization of layers or surfaces. Especially the control of the process energy inside the beam and at its edges opens a large area of laser applications that can be addressed only with an optimized spatial and angular beam profile with down to sub-percent intensity variation used in e.g. immersion lithography tools with ArF laser sources. LIMO will present examples for new beam shapes and related material refinement processes even on large surfaces and give an overview about new mechanisms in laser material processing for current and coming industrial applications.

Improving material removal determinacy based on the compensation of tool influence function

NASA Astrophysics Data System (ADS)

Zhong, Bo; Chen, Xian-hua; Deng, Wen-hui; Zhao, Shi-jie; Zheng, Nan

2018-03-01

In the process of computer-controlled optical surfacing (CCOS), the key of correcting the surface error of optical components is to ensure the consistency between the simulated tool influence function and the actual tool influence function (TIF). The existing removal model usually adopts the fixed-point TIF to remove the material with the planning path and velocity, and it considers that the polishing process is linear and time invariant. However, in the actual polishing process, the TIF is a function related to the feed speed. In this paper, the relationship between the actual TIF and the feed speed (i.e. the compensation relationship between static removal and dynamic removal) is determined by experimental method. Then, the existing removal model is modified based on the compensation relationship, to improve the conformity between simulated and actual processing. Finally, the surface error modification correction test are carried out. The results show that the fitting degree of the simulated surface and the experimental surface is better than 88%, and the surface correction accuracy can be better than 1/10 λ (Λ=632.8nm).

Contributions of nanodiamond abrasives and deionized water in magnetorheological finishing of aluminum oxynitriden

NASA Astrophysics Data System (ADS)

Miao, Chunlin; Lambropoulos, John C.; Romanofsky, Henry; Shafrir, Shai N.; Jacobs, Stephen D.

2009-08-01

Magnetorheological finishing (MRF) is a sub-aperture deterministic process for fabricating high-precision optics by removing material and smoothing the surface. The goal of this work is to study the relative contribution of nanodiamonds and water in material removal for MRF of aluminum oxynitride ceramic (ALON) based upon a nonaqueous magnetorheological (MR) fluid. Removal was enhanced by a high carbonyl iron concentration and the addition of nanodiamond abrasives. Small amounts of deionized (DI) water were introduced into the nonaqueous MR fluid to further influence the material removal process. Material removal data were collected with a spot-taking machine. Drag force (Fd) and normal force (Fn) before and after adding nanodiamonds or DI water were measured with a dual load cell. Both drag force and normal force were insensitive to the addition of nanodiamonds but increased with DI water content in the nonaqueous MR fluid. Shear stress (i.e., drag force divided by spot area) was calculated, and examined as a function of nanodiamond concentration and DI water concentration. Volumetric removal rate increased with increasing shear stress, which was shown to be a result of increasing viscosity after adding nanodiamonds and DI water. This work demonstrates that removal rate for a hard ceramic with MRF can be enhanced by adding DI water into a nonaqueous MR fluid.

An Innovative Porous Nanocomposite Material for the Removal of Phenolic Compounds from Aqueous Solutions.

PubMed

Turco, Antonio; Monteduro, Anna Grazia; Mazzotta, Elisabetta; Maruccio, Giuseppe; Malitesta, Cosimino

2018-05-16

Energy efficient, low-cost, user-friendly, and green methods for the removal of toxic phenolic compounds from aqueous solution are necessary for waste treatment in industrial applications. Herein we present an interesting approach for the utilization of oxidized carbon nanotubes (CNTs) in the removal of phenolic compounds from aqueous solution. Dried pristine CNTs were stably incorporated in a solid porous support of polydimethylsiloxane (PDMS) facilitating the handling during both oxidation process of the nanomaterial and uptake of phenolic compounds, and enabling their safe disposal, avoiding expensive post-treatment processes. The adsorption studies indicated that the materials can efficiently remove phenolic compounds from water with different affinities towards different phenolic compounds. Furthermore, the adsorption kinetics and isotherms were studied in detail. The experimental data of adsorption fitted well with Langmuir and Freundlich isotherms, and pseudo-second-order kinetics, and the results indicated that the adsorption process was controlled by a two-step intraparticle diffusion model. The incorporation of CNTs in polymeric matrices did not affect their functionality in phenol uptake. The material was also successfully used for the removal of phenolic compounds from agricultural waste, suggesting its possible application in the treatment of wastewater. Moreover, the surface of the material could be regenerated, decreasing treatment costs.

Improved methane removal in exhaust gas from biogas upgrading process using immobilized methane-oxidizing bacteria.

PubMed

Sun, Meng-Ting; Yang, Zhi-Man; Fu, Shan-Fei; Fan, Xiao-Lei; Guo, Rong-Bo

2018-05-01

Methane in exhaust gas from biogas upgrading process, which is a greenhouse gas, could cause global warming. The biofilter with immobilized methane-oxidizing bacteria (MOB) is a promising approach for methane removal, and the selections of inoculated MOB culture and support material are vital for the biofilter. In this work, five MOB consortia were enriched at different methane concentrations. The MOB-20 consortium enriched at the methane concentration of 20.0% (v/v) was then immobilized on sponge and two particle sizes of volcanic rock in biofilters to remove methane in exhaust gas from biogas upgrading process. Results showed that the immobilized MOB performed more admirable methane removal capacity than suspended cells. The immobilized MOB on sponge reached the highest methane removal efficiency (RE) of 35%. The rough surface, preferable hydroscopicity, appropriate pore size and particle size of support material might favor the MOB immobilization and accordingly methane removal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Figure and caption for LDRD annual report

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

Suratwala, T.

2017-10-16

Material removal rate of various optical material workpieces polished using various colloidal slurries as a function of partial charge difference. Partial charge difference is a parameter calculated from a new chemical model proposed to link the condensation reaction rate with polishing material removal rate. This chemical model can serve as a global platform to predict & design polishing processes for a wide variety of workpiece materials and slurry compositions.

REMOVAL OF LEGACY PLUTONIUM MATERIALS FROM SWEDEN

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

Dunn, Kerry A.; Bellamy, J. Steve; Chandler, Greg T.

2013-08-18

U.S. Department of Energy’s National Nuclear Security Administration (NNSA) Office of Global Threat Reduction (GTRI) recently removed legacy plutonium materials from Sweden in collaboration with AB SVAFO, Sweden. This paper details the activities undertaken through the U.S. receiving site (Savannah River Site (SRS)) to support the characterization, stabilization, packaging and removal of legacy plutonium materials from Sweden in 2012. This effort was undertaken as part of GTRI’s Gap Materials Program and culminated with the successful removal of plutonium from Sweden as announced at the 2012 Nuclear Security Summit. The removal and shipment of plutonium materials to the United States wasmore » the first of its kind under NNSA’s Global Threat Reduction Initiative. The Environmental Assessment for the U.S. receipt of gap plutonium material was approved in May 2010. Since then, the multi-year process yielded many first time accomplishments associated with plutonium packaging and transport activities including the application of the of DOE-STD-3013 stabilization requirements to treat plutonium materials outside the U.S., the development of an acceptance criteria for receipt of plutonium from a foreign country, the development and application of a versatile process flow sheet for the packaging of legacy plutonium materials, the identification of a plutonium container configuration, the first international certificate validation of the 9975 shipping package and the first intercontinental shipment using the 9975 shipping package. This paper will detail the technical considerations in developing the packaging process flow sheet, defining the key elements of the flow sheet and its implementation, determining the criteria used in the selection of the transport package, developing the technical basis for the package certificate amendment and the reviews with multiple licensing authorities and most importantly integrating the technical activities with the Swedish partners.« less

Material removal in magnetorheological finishing of optics.

PubMed

Kordonski, William; Gorodkin, Sergei

2011-05-10

A concept of material removal based on the principle of conservation of particles momentum in a binary suspension is applied to analyze material removal in magnetorheological finishing and magnetorheological jet processes widely used in precision optics fabrication. According to this concept, a load for surface indentation by abrasive particles is provided at their interaction near the wall with heavier basic (magnetic) particles, which fluctuate (due to collision) in the shear flow of concentrated suspension. The model is in good qualitative and quantitative agreement with experimental results.

Process for minimizing solids contamination of liquids from coal pyrolysis

DOEpatents

Wickstrom, Gary H.; Knell, Everett W.; Shaw, Benjamin W.; Wang, Yue G.

1981-04-21

In a continuous process for recovery of liquid hydrocarbons from a solid carbonaceous material by pyrolysis of the carbonaceous material in the presence of a particulate source of heat, particulate contamination of the liquid hydrocarbons is minimized. This is accomplished by removing fines from the solid carbonaceous material feed stream before pyrolysis, removing fines from the particulate source of heat before combining it with the carbonaceous material to effect pyrolysis of the carbonaceous material, and providing a coarse fraction of reduced fines content of the carbon containing solid residue resulting from the pyrolysis of the carbonaceous material before oxidizing carbon in the carbon containing solid residue to form the particulate source of heat.

Removal of plutonium from hepatic tissue

DOEpatents

Lindenbaum, Arthur; Rosenthal, Marcia W.

1979-01-01

A method is provided for removing plutonium from hepatic tissues by introducing into the body and blood stream a solution of the complexing agent DTPA and an adjunct thereto. The adjunct material induces aberrations in the hepatic tissue cells and removes intracellularly deposited plutonium which is normally unavailable for complexation with the DTPA. Once the intracellularly deposited plutonium has been removed from the cell by action of the adjunct material, it can be complexed with the DTPA present in the blood stream and subsequently removed from the body by normal excretory processes.

Computer Controlled Optical Surfacing With Orbital Tool Motion

NASA Astrophysics Data System (ADS)

Jones, Robert A.

1985-10-01

Asymmetric aspheric optical surfaces are very difficult to fabricate using classical techniques and laps the same size as the workpiece. Opticians can produce such surfaces by grinding and polishing, using small laps with orbital tool motion. However, hand correction is a time consuming process unsuitable for large optical elements. Itek has developed Computer Controlled Optical Surfacing (CCOS) for fabricating such aspheric optics. Automated equipment moves a nonrotating orbiting tool slowly over the workpiece surface. The process corrects low frequency surface errors by figuring. The velocity of the tool assembly over the workpiece surface is purposely varied. Since the amount of material removal is proportional to the polishing or grinding time, accurate control over material removal is achieved. The removal of middle and high frequency surface errors is accomplished by pad smoothing. For a soft pad material, the pad will compress to fit the workpiece surface producing greater pressure and more removal at the surface high areas. A harder pad will ride on only the high regions resulting in removal only for those locations.

Post-cast EDM method for reducing the thickness of a turbine nozzle wall

DOEpatents

Jones, Raymond Joseph; Bojappa, Parvangada Ganapathy; Kirkpatrick, Francis Lawrence; Schotsch, Margaret Jones; Rajan, Rajiv; Wei, Bin

2002-01-01

A post-cast EDM process is used to remove material from the interior surface of a nozzle vane cavity of a turbine. A thin electrode is passed through the cavity between opposite ends of the nozzle vane and displaced along the interior nozzle wall to remove the material along a predetermined path, thus reducing the thickness of the wall between the cavity and the external surface of the nozzle. In another form, an EDM process employing a profile as an electrode is disposed in the cavity and advanced against the wall to remove material from the wall until the final wall thickness is achieved, with the interior wall surface being complementary to the profile surface.

Tribochemical investigation of microelectronic materials

NASA Astrophysics Data System (ADS)

Kulkarni, Milind Sudhakar

To achieve efficient planarization with reduced device dimensions in integrated circuits, a better understanding of the physics, chemistry, and the complex interplay involved in chemical mechanical planarization (CMP) is needed. The CMP process takes place at the interface of the pad and wafer in the presence of the fluid slurry medium. The hardness of Cu is significantly less than the slurry abrasive particles which are usually alumina or silica. It has been accepted that a surface layer can protect the Cu surface from scratching during CMP. Four competing mechanisms in materials removal have been reported: the chemical dissolution of Cu, the mechanical removal through slurry abrasives, the formation of thin layer of Cu oxide and the sweeping surface material by slurry flow. Despite the previous investigation of Cu removal, the electrochemical properties of Cu surface layer is yet to be understood. The motivation of this research was to understand the fundamental aspects of removal mechanisms in terms of electrochemical interactions, chemical dissolution, mechanical wear, and factors affecting planarization. Since one of the major requirements in CMP is to have a high surface finish, i.e., low surface roughness, optimization of the surface finish in reference to various parameters was emphasized. Three approaches were used in this research: in situ measurement of material removal, exploration of the electropotential activation and passivation at the copper surface and modeling of the synergistic electrochemical-mechanical interactions on the copper surface. In this research, copper polishing experiments were conducted using a table top tribometer. A potentiostat was coupled with this tribometer. This combination enabled the evaluation of important variables such as applied pressure, polishing speed, slurry chemistry, pH, materials, and applied DC potential. Experiments were designed to understand the combined and individual effect of electrochemical interactions as well as mechanical impact during polishing. Extensive surface characterization was performed with AFM, SEM, TEM and XPS. An innovative method for direct material removal measurement on the nanometer scale was developed and used. Experimental observations were compared with the theoretically calculated material removal rate values. The synergistic effect of all of the components of the process, which result in a better quality surface finish was quantitatively evaluated for the first time. Impressed potential during CMP proved to be a controlling parameter in the material removal mechanism. Using the experimental results, a model was developed, which provided a practical insight into the CMP process. The research is expected to help with electrochemical material removal in copper planarization with low-k dielectrics.

Calibration and prediction of removal function in magnetorheological finishing.

PubMed

Dai, Yifan; Song, Ci; Peng, Xiaoqiang; Shi, Feng

2010-01-20

A calibrated and predictive model of the removal function has been established based on the analysis of a magnetorheological finishing (MRF) process. By introducing an efficiency coefficient of the removal function, the model can be used to calibrate the removal function in a MRF figuring process and to accurately predict the removal function of a workpiece to be polished whose material is different from the spot part. Its correctness and feasibility have been validated by simulations. Furthermore, applying this model to the MRF figuring experiments, the efficiency coefficient of the removal function can be identified accurately to make the MRF figuring process deterministic and controllable. Therefore, all the results indicate that the calibrated and predictive model of the removal function can improve the finishing determinacy and increase the model applicability in a MRF process.

Gas stream clean-up filter and method for forming same

DOEpatents

Mei, Joseph S.; DeVault, James; Halow, John S.

1993-01-01

A gas cleaning filter is formed in-situ within a vessel containing a fluidizable bed of granular material of a relatively large size fraction. A filter membrane provided by a porous metal or ceramic body or such a body supported a perforated screen on one side thereof is coated in-situ with a layer of the granular material from the fluidized bed by serially passing a bed-fluidizing gas stream through the bed of granular material and the membrane. The layer of granular material provides the filtering medium for the combined membrane-granular layer filter. The filter is not blinded by the granular material and provides for the removal of virtually all of the particulates from a process gas stream. The granular material can be at least partially provided by a material capable of chemically reacting with and removing sulfur compounds from the process gas stream. Low level radioactive waste containing organic material may be incinerated in a fluidized bed in communication with the described filter for removing particulates from the gaseous combustion products.

Biomachining - A new approach for micromachining of metals

NASA Astrophysics Data System (ADS)

Vigneshwaran, S. C. Sakthi; Ramakrishnan, R.; Arun Prakash, C.; Sashank, C.

2018-04-01

Machining is the process of removal of material from workpiece. Machining can be done by physical, chemical or biological methods. Though physical and chemical methods have been widely used in machining process, they have their own disadvantages such as development of heat affected zone and usage of hazardous chemicals. Biomachining is the machining process in which bacteria is used to remove material from the metal parts. Chemolithotrophic bacteria such as Acidothiobacillus ferroxidans has been used in biomachining of metals like copper, iron etc. These bacteria are used because of their property of catalyzing the oxidation of inorganic substances. Biomachining is a suitable process for micromachining of metals. This paper reviews the biomachining process and various mechanisms involved in biomachining. This paper also briefs about various parameters/factors to be considered in biomachining and also the effect of those parameters on metal removal rate.

Contributions of Nanodiamond Abrasives and Deionized Water in Magnetorheological Finishing of Aluminum Oxynitride

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

Miao, C.; Lambropoulos, J.C.; Romanofsky, H.

2010-01-13

Magnetorheological finishing (MRF) is a sub-aperture deterministic process for fabricating high-precision optics by removing material and smoothing the surface. The goal of this work is to study the relative contribution of nanodiamonds and water in material removal for MRF of aluminum oxynitride ceramic (ALON) based upon a nonaqueous magnetorheological (MR) fluid. Removal was enhanced by a high carbonyl iron concentration and the addition of nanodiamond abrasives. Small amounts of deionized (DI) water were introduced into the nonaqueous MR fluid to further influence the material removal process. Material removal data were collected with a spot-taking machine. Drag force (Fd) and normalmore » force (Fn) before and after adding nanodiamonds or DI water were measured with a dual load cell. Both drag force and normal force were insensitive to the addition of nanodiamonds but increased with DI water content in the nonaqueous MR fluid. Shear stress (i.e., drag force divided by spot area) was calculated, and examined as a function of nanodiamond concentration and DI water concentration. Volumetric removal rate increased with increasing shear stress, which was shown to be a result of increasing viscosity after adding nanodiamonds and DI water. This work demonstrates that removal rate for a hard ceramic with MRF can be enhanced by adding DI water into a nonaqueous MR fluid.« less

SPATIAL DISTRIBUTION OF CARBON AND SULFUR PRECIPITATING WITHIN PERMEABLE REACTIVE BARRIERS: DEVELOPMENT OF ANALYTICAL METHODS

EPA Science Inventory

A permeable reactive barrier (PRB) is a wall of porous reactive material placed in the path of a dissolved contaminant plume for the purpose of removing contaminants from ground water. Chemical processes within these reactive materials remove both inorganic and organic contamina...

Laser-assisted focused He + ion beam induced etching with and without XeF 2 gas assist

DOE PAGES

Stanford, Michael G.; Mahady, Kyle; Lewis, Brett B.; ...

2016-10-04

Focused helium ion (He +) milling has been demonstrated as a high-resolution nanopatterning technique; however, it can be limited by its low sputter yield as well as the introduction of undesired subsurface damage. Here, we introduce pulsed laser- and gas-assisted processes to enhance the material removal rate and patterning fidelity. A pulsed laser-assisted He+ milling process is shown to enable high-resolution milling of titanium while reducing subsurface damage in situ. Gas-assisted focused ion beam induced etching (FIBIE) of Ti is also demonstrated in which the XeF 2 precursor provides a chemical assist for enhanced material removal rate. In conclusion, amore » pulsed laser-assisted and gas-assisted FIBIE process is shown to increase the etch yield by ~9× relative to the pure He+ sputtering process. These He + induced nanopatterning techniques improve material removal rate, in comparison to standard He + sputtering, while simultaneously decreasing subsurface damage, thus extending the applicability of the He + probe as a nanopattering tool.« less

Laser-assisted focused He + ion beam induced etching with and without XeF 2 gas assist

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

Stanford, Michael G.; Mahady, Kyle; Lewis, Brett B.

Focused helium ion (He +) milling has been demonstrated as a high-resolution nanopatterning technique; however, it can be limited by its low sputter yield as well as the introduction of undesired subsurface damage. Here, we introduce pulsed laser- and gas-assisted processes to enhance the material removal rate and patterning fidelity. A pulsed laser-assisted He+ milling process is shown to enable high-resolution milling of titanium while reducing subsurface damage in situ. Gas-assisted focused ion beam induced etching (FIBIE) of Ti is also demonstrated in which the XeF 2 precursor provides a chemical assist for enhanced material removal rate. In conclusion, amore » pulsed laser-assisted and gas-assisted FIBIE process is shown to increase the etch yield by ~9× relative to the pure He+ sputtering process. These He + induced nanopatterning techniques improve material removal rate, in comparison to standard He + sputtering, while simultaneously decreasing subsurface damage, thus extending the applicability of the He + probe as a nanopattering tool.« less

Recent developments in turbomachinery component materials and manufacturing challenges for aero engine applications

NASA Astrophysics Data System (ADS)

Srinivas, G.; Raghunandana, K.; Satish Shenoy, B.

2018-02-01

In the recent years the development of turbomachinery materials performance enhancement plays a vital role especially in aircraft air breathing engines like turbojet engine, turboprop engine, turboshaft engine and turbofan engines. Especially the transonic flow engines required highly sophisticated materials where it can sustain the entire thrust which can create by the engine. The main objective of this paper is to give an overview of the present cost-effective and technological capabilities process for turbomachinery component materials. Especially the main focus is given to study the Electro physical, Photonic additive removal process and Electro chemical process for turbomachinery parts manufacture. The aeronautical propulsion based technologies are reviewed thoroughly where in surface reliability, geometrical precession, and material removal and highly strengthened composite material deposition rates usually difficult to cut dedicated steels, Titanium and Nickel based alloys. In this paper the past aeronautical and propulsion mechanical based manufacturing technologies, current sophisticated technologies and also future challenging material processing techniques are covered. The paper also focuses on the brief description of turbomachinery components of shaping process and coating in aeromechanical applications.

SEMICONDUCTOR TECHNOLOGY: Material removal rate in chemical-mechanical polishing of wafers based on particle trajectories

NASA Astrophysics Data System (ADS)

Jianxiu, Su; Xiqu, Chen; Jiaxi, Du; Renke, Kang

2010-05-01

Distribution forms of abrasives in the chemical mechanical polishing (CMP) process are analyzed based on experimental results. Then the relationships between the wafer, the abrasive and the polishing pad are analyzed based on kinematics and contact mechanics. According to the track length of abrasives on the wafer surface, the relationships between the material removal rate and the polishing velocity are obtained. The analysis results are in accord with the experimental results. The conclusion provides a theoretical guide for further understanding the material removal mechanism of wafers in CMP.

Removal of toxic zinc from water/wastewater using eucalyptus seeds activated carbon: non-linear regression analysis.

PubMed

Senthil Kumar, Ponnusamy; Saravanan, Anbalagan; Anish Kumar, Kodyingil; Yashwanth, Ramesh; Visvesh, Sridharan

2016-08-01

In the present study, a novel activated carbon was prepared from low-cost eucalyptus seeds, which was utilised for the effectively removal of toxic zinc from the water/wastewater. The prepared adsorbent was studied by Fourier transform infrared spectroscopy and scanning electron microscopic characterisation studies. Adsorption process was experimentally performed for optimising the influencing factors such as adsorbent dosage, solution pH, contact time, initial zinc concentration, and temperature for the maximum removal of zinc from aqueous solution. Adsorption isotherm of zinc removal was ensued Freundlich model, and the kinetic model ensued pseudo-second order model. Langmuir monolayer adsorption capacity of the adsorbent for zinc removal was evaluated as 80.37 mg/g. The results of the thermodynamic studies suggested that the adsorption process was exothermic, thermodynamically feasible and impulsive process. Finally, a batch adsorber was planned to remove zinc from known volume and known concentration of wastewater using best obeyed model such as Freundlich. The experimental details showed the newly prepared material can be effectively utilised as a cheap material for the adsorption of toxic metal ions from the contaminated water.

Thermal-mechanical modeling of laser ablation hybrid machining

NASA Astrophysics Data System (ADS)

Matin, Mohammad Kaiser

2001-08-01

Hard, brittle and wear-resistant materials like ceramics pose a problem when being machined using conventional machining processes. Machining ceramics even with a diamond cutting tool is very difficult and costly. Near net-shape processes, like laser evaporation, produce micro-cracks that require extra finishing. Thus it is anticipated that ceramic machining will have to continue to be explored with new-sprung techniques before ceramic materials become commonplace. This numerical investigation results from the numerical simulations of the thermal and mechanical modeling of simultaneous material removal from hard-to-machine materials using both laser ablation and conventional tool cutting utilizing the finite element method. The model is formulated using a two dimensional, planar, computational domain. The process simulation acronymed, LAHM (Laser Ablation Hybrid Machining), uses laser energy for two purposes. The first purpose is to remove the material by ablation. The second purpose is to heat the unremoved material that lies below the ablated material in order to ``soften'' it. The softened material is then simultaneously removed by conventional machining processes. The complete solution determines the temperature distribution and stress contours within the material and tracks the moving boundary that occurs due to material ablation. The temperature distribution is used to determine the distance below the phase change surface where sufficient ``softening'' has occurred, so that a cutting tool may be used to remove additional material. The model incorporated for tracking the ablative surface does not assume an isothermal melt phase (e.g. Stefan problem) for laser ablation. Both surface absorption and volume absorption of laser energy as function of depth have been considered in the models. LAHM, from the thermal and mechanical point of view is a complex machining process involving large deformations at high strain rates, thermal effects of the laser, removal of materials and contact between workpiece and tool. The theoretical formulation associated with LAHM for solving the thermal-mechanical problem using the finite element method is presented. The thermal formulation is incorporated in the user defined subroutines called by ABAQUS/Standard. The mechanical portion is modeled using ABAQUS/Explicit's general capabilities of modeling interactions involving contact and separation. The results obtained from the FEA simulations showed that the cutting force decrease considerably in both LAEM Surface Absorption (LARM-SA) and LAHM volume absorption (LAHM-VA) models relative to LAM model. It was observed that the HAZ can be expanded or narrowed depending on the laser speed and power. The cutting force is minimal at the last extent of the HAZ. In both the models the laser ablates material thus reducing material stiffness as well as relaxing the thermal stress. The stress values obtained showed compressive yield stress just below the ablated surface and chip. The failure occurs by conventional cutting where tensile stress exceeds the tensile strength of the material at that temperature. In this hybrid machining process the advantages of both the individual machining processes were realized.

27 CFR 19.315 - Removal or destruction of distilling material.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Removal or destruction of distilling material. 19.315 Section 19.315 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND...) spirits, (2) alcoholic beverages, or (3) vinegar by the vaporizing process; or (c) for destruction. The...

The Effect of Material Removal on the Corrosion Resistance and Biocompatibility of Nitinol Laser-Cut and Wire-Form Products

NASA Astrophysics Data System (ADS)

Decker, Jennifer Fino; Trépanier, Christine; Vien, Lot; Pelton, Alan R.

2011-07-01

Laser cutting and wire forming are two of the most commonly used processes in the manufacture of Nitinol medical devices. This study explores how varying the amount of material removed during the final surface treatment steps affects the corrosion resistance of Z-type stents that have either been laser-cut from tube or shape set from wire. All parts were subjected to a typical heat treatment process necessary to achieve an Austenite finish (Af) temperature of 25 ± 5 °C, and were subsequently post-processed with an electrochemical passivation process. The total weight loss during post-processing was recorded and the process adjusted to create groups with less than 5%, less than 10%, and less than 25% amounts of weight loss. The parts were then crimped to 6 mm and allowed to expand back to their original diameter. The corrosion test results showed that on average both groups of Z-stents experienced an increase in the corrosion breakdown potential and a decrease in the standard deviation with increasing amounts of material removal. In addition, less material removal is required from the wire-form Z-stents as compared to the laser-cut Z-stents to achieve high corrosion resistance. Finally, 7 day nickel ion release tests performed on the wire-formed Z-stents showed a dramatic decrease from 0.0132 mg of nickel leached per day for the low weight loss group to approximately 0.001 mg/day for the medium and high weight loss groups.

Characterization of dissolved organic matter in landfill leachate during the combined treatment process of air stripping, Fenton, SBR and coagulation

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

Liu, ZhiPing, E-mail: liulqs@163.com; Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400020; Wu, WenHui

Highlights: • DOM fractions spectra analysis during the whole treatment process. • Efficient method was achieved to remove organic matters in landfill leachate. • Molecular weight distribution and fractions were discussed. - Abstract: A combined treatment process of air stripping + Fenton + sequencing batch reactor (SBR)+ coagulation was performed to remove the pollutants in landfill leachate. Molecular weight (MW) distribution and fractions of dissolved organic matter (DOM) were discussed to study the characteristics. The experiment showed that the removal rate of chemical oxygen demand (COD), five day biological oxygen demand (BOD{sub 5}) and ammonia nitrogen (NH{sub 3}−N) by themore » combined process were 92.8%, 87.8% and 98.0%, respectively. Humic acid (HA) and fulvic acid (FA) were the main fractions in raw leachate with 81.8% of the total COD concentration, while hydrophilic organic matter (HyI) was the dominant fraction in the final effluent of the combined process with 63.5% of the total COD concentration. After the combined treatment process, the removal rate of DOM and fractions HA, FA, HyI were 91.9%, 97.1%, 95.8% and 71.7%, respectively. Organic matters of MW < 2 k and MW > 100 k were removed with 90.5% and 97.9% COD concentration after the treatment. The ultraviolet–visible spectra (UV–vis), Fourier transform infrared spectra (FTIR) and three-dimensional excitation-emission matrices spectra (EEMs) indicated that benzene materials and phenol compounds were preferentially removed in air stripping. High MW matters, aromatic rings, conjugated moieties and some functional groups were mainly removed by Fenton. While small MW fractions, carboxylic acids, alcohols and protein-like materials were preferentially biodegraded via SBR. Fulvic-like and humic-like materials were mainly destroyed via Fenton oxidation and coagulation.« less

Liquid Nitrogen Removal of Critical Aerospace Materials

NASA Technical Reports Server (NTRS)

Noah, Donald E.; Merrick, Jason; Hayes, Paul W.

2005-01-01

Identification of innovative solutions to unique materials problems is an every-day quest for members of the aerospace community. Finding a technique that will minimize costs, maximize throughput, and generate quality results is always the target. United Space Alliance Materials Engineers recently conducted such a search in their drive to return the Space Shuttle fleet to operational status. The removal of high performance thermal coatings from solid rocket motors represents a formidable task during post flight disassembly on reusable expended hardware. The removal of these coatings from unfired motors increases the complexity and safety requirements while reducing the available facilities and approved processes. A temporary solution to this problem was identified, tested and approved during the Solid Rocket Booster (SRB) return to flight activities. Utilization of ultra high-pressure liquid nitrogen (LN2) to strip the protective coating from assembled space shuttle hardware marked the first such use of the technology in the aerospace industry. This process provides a configurable stream of liquid nitrogen (LN2) at pressures of up to 55,000 psig. The performance of a one-time certification for the removal of thermal ablatives from SRB hardware involved extensive testing to ensure adequate material removal without causing undesirable damage to the residual materials or aluminum substrates. Testing to establish appropriate process parameters such as flow, temperature and pressures of the liquid nitrogen stream provided an initial benchmark for process testing. Equipped with these initial parameters engineers were then able to establish more detailed test criteria that set the process limits. Quantifying the potential for aluminum hardware damage represented the greatest hurdle for satisfying engineers as to the safety of this process. Extensive testing for aluminum erosion, surface profiling, and substrate weight loss was performed. This successful project clearly demonstrated that the liquid nitrogen jet possesses unique strengths that align remarkably well with the unusual challenges that space hardware and missile manufacturers face on a regular basis. Performance of this task within the confines of a critical manufacturing facility marks a milestone in advanced processing.

A novel route for the removal of bodily heavy metal lead (II)

NASA Astrophysics Data System (ADS)

Huang, Weirong; Zhang, Penghua; Xu, Hui; Chang, Shengli; He, Yongju; Wang, Fei; Liang, Gaowei

2015-09-01

The lead ion concentration in bile is considerably higher than in blood, and bile is released into the alimentary tract. Thiol-modified SBA-15 administered orally can combine with lead ions in the alimentary tract. In this paper, the in vitro lead absorption of bile was investigated. This thiol-modified SBA-15 material was used in pharmacodynamics studies on rabbits. The result that the lead content in faeces was notably higher indicates that thiol-modified SBA-15 can efficiently remove lead. The mechanism could include the following: thiol-modified SBA-15 material cuts off the heavy metal lead recirculation in the process of bile enterohepatic circulation by chelating the lead in the alimentary tract, causing a certain proportion of lead to be removed by the thiol mesoporous material, and the lead is subsequently egested out of the body in faeces. The results indicate that this material might be a potential non-injection material for the removal bodily heavy metal lead in the alimentary tract. This material may also be a useful means of lead removal, especially for non-acute sub-poisoning symptoms.

An environmentally safe and effective paint removal process for aircraft

NASA Astrophysics Data System (ADS)

Kozol, Joseph

2001-03-01

To reduce hazardous waste from fleet and depot aircraft paint stripping and to conform to regulations banning toxic chemical paint strippers, the U.S. Naval Air Systems Team (materials division, depots, and head-quarters) teamed with the U.S. Air Force at Warner Robins Air Logistics Center for concept development, characterization, and demonstration of a mature, advanced paint-removal system, the Boeing xenon/flashlamp CO2 (Flashjet®) process. Extensive metallic and composite-materials testing was conducted. This paper describes the development and characterization program leading to authorization of the process for use on fixed-wing navy aircraft.

Ablation-cooled material removal with ultrafast bursts of pulses

NASA Astrophysics Data System (ADS)

Kerse, Can; Kalaycıoğlu, Hamit; Elahi, Parviz; Çetin, Barbaros; Kesim, Denizhan K.; Akçaalan, Önder; Yavaş, Seydi; Aşık, Mehmet D.; Öktem, Bülent; Hoogland, Heinar; Holzwarth, Ronald; Ilday, Fatih Ömer

2016-09-01

The use of femtosecond laser pulses allows precise and thermal-damage-free removal of material (ablation) with wide-ranging scientific, medical and industrial applications. However, its potential is limited by the low speeds at which material can be removed and the complexity of the associated laser technology. The complexity of the laser design arises from the need to overcome the high pulse energy threshold for efficient ablation. However, the use of more powerful lasers to increase the ablation rate results in unwanted effects such as shielding, saturation and collateral damage from heat accumulation at higher laser powers. Here we circumvent this limitation by exploiting ablation cooling, in analogy to a technique routinely used in aerospace engineering. We apply ultrafast successions (bursts) of laser pulses to ablate the target material before the residual heat deposited by previous pulses diffuses away from the processing region. Proof-of-principle experiments on various substrates demonstrate that extremely high repetition rates, which make ablation cooling possible, reduce the laser pulse energies needed for ablation and increase the efficiency of the removal process by an order of magnitude over previously used laser parameters. We also demonstrate the removal of brain tissue at two cubic millimetres per minute and dentine at three cubic millimetres per minute without any thermal damage to the bulk.

Ablation-cooled material removal with ultrafast bursts of pulses.

PubMed

Kerse, Can; Kalaycıoğlu, Hamit; Elahi, Parviz; Çetin, Barbaros; Kesim, Denizhan K; Akçaalan, Önder; Yavaş, Seydi; Aşık, Mehmet D; Öktem, Bülent; Hoogland, Heinar; Holzwarth, Ronald; Ilday, Fatih Ömer

2016-09-01

The use of femtosecond laser pulses allows precise and thermal-damage-free removal of material (ablation) with wide-ranging scientific, medical and industrial applications. However, its potential is limited by the low speeds at which material can be removed and the complexity of the associated laser technology. The complexity of the laser design arises from the need to overcome the high pulse energy threshold for efficient ablation. However, the use of more powerful lasers to increase the ablation rate results in unwanted effects such as shielding, saturation and collateral damage from heat accumulation at higher laser powers. Here we circumvent this limitation by exploiting ablation cooling, in analogy to a technique routinely used in aerospace engineering. We apply ultrafast successions (bursts) of laser pulses to ablate the target material before the residual heat deposited by previous pulses diffuses away from the processing region. Proof-of-principle experiments on various substrates demonstrate that extremely high repetition rates, which make ablation cooling possible, reduce the laser pulse energies needed for ablation and increase the efficiency of the removal process by an order of magnitude over previously used laser parameters. We also demonstrate the removal of brain tissue at two cubic millimetres per minute and dentine at three cubic millimetres per minute without any thermal damage to the bulk.

Tuning the pH-shift protein-isolation method for maximum hemoglobin-removal from blood rich fish muscle.

PubMed

Abdollahi, Mehdi; Marmon, Sofia; Chaijan, Manat; Undeland, Ingrid

2016-12-01

A main challenge preventing optimal use of protein isolated from unconventional raw materials (e.g., small pelagic fish and fish by-products) using the pH-shift method is the difficulty to remove enough heme-pigments. Here, the distribution of hemoglobin (Hb) in the different fractions formed during pH-shift processing was studied using Hb-fortified cod mince. Process modifications, additives and prewashing were then investigated to further facilitate Hb-removal. The alkaline pH-shift process version could remove considerably more Hb (77%) compared to the acidic version (37%) when proteins were precipitated at pH 5.5; most Hb was removed during dewatering. Protein precipitation at pH 6.5 improved total Hb removal up to 91% and 74% during alkaline and acid processing, respectively. Adding phytic acid to the first supernatant of the alkaline process version yielded 93% Hb removal. Combining one prewash with phytic acid at pH 5.5 followed by alkaline/acid pH-shift processing increased Hb removal up to 96/92%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Laser Material Processing for Microengineering Applications

NASA Technical Reports Server (NTRS)

Helvajian, H.

1995-01-01

The processing of materials via laser irradiation is presented in a brief survey. Various techniques currently used in laser processing are outlined and the significance to the development of space qualified microinstrumentation are identified. In general the laser processing technique permits the transferring of patterns (i.e. lithography), machining (i.e. with nanometer precision), material deposition (e.g., metals, dielectrics), the removal of contaminants/debris/passivation layers and the ability to provide process control through spectroscopy.

Formation mechanism of the photomask blanks material related haze

NASA Astrophysics Data System (ADS)

Kim, Jung-Jin; Choi, Junyoul; Koh, Soowan; Kim, Minho; Lee, Jiyoung; Lee, Han-Shin; Kim, Byung Gook; Jeon, Chan-uk

2016-05-01

We have observed a new type haze of which formation deviates from the generally accepted models with respect to the size, shape, and removability by chemicals. It has very small size of 50~100nm and are crowded around the cell boundary, while the typical haze doesn't prefer a special region on mask in the majority of cases. It is hard to remove by general cleaning, while the typical haze is easily removed by general cleaning process and even de-ionized water. It is confirmed that the source of the haze is blank material related ions which are formed by chemical etching of blanks during mask cleaning process or the photomask blanks itself.

Dyes removal from textile wastewater using graphene based nanofiltration

NASA Astrophysics Data System (ADS)

Makertihartha, I. G. B. N.; Rizki, Z.; Zunita, M.; Dharmawijaya, P. T.

2017-05-01

Wastewater produced from textile industry is having more strict regulation. The major pollutant of wastewater from textile industry is Dyes. Dyes have several harsh properties i.e toxic, volatile, complexing easily with mineral ions that are dissolved in water (decreasing the amount of important mineral ions in water), and hard to disintegrate, therefore it must be removed from the waste stream. There are several methods and mechanisms to remove dyes such as chemical and physical sorption, evaporation, biological degradation, and photocatalytic system that can be applied to the waste stream. Membrane-based separation technology has been introduced in dyes removal treatment and is well known for its advantages (flexibility, mild operating condition, insensitive to toxic pollutant). Graphene and its derivatives are novel materials which have special properties due to its ultrathin layer and nanometer-size pores. Thus, the materials are very light yet strong. Moreover, it has low cost and easy to fabricate. Recently, the application of graphene and its derivatives in nanofiltration membrane processes is being widely explored. This review investigates the potentials of graphene based membrane in dyes removal processes. The operating conditions, dyes removal effectiveness, and the drawbacks of the process are the main focus in this paper.

A Guide for Developing Standard Operating Job Procedures for the Grit Removal Process Wastewater Treatment Facility. SOJP No. 2.

ERIC Educational Resources Information Center

Deal, Gerald A.; Montgomery, James A.

This guide describes standard operating job procedures for the grit removal process of wastewater treatment plants. Step-by-step instructions are given for pre-start up inspection, start-up, continuous operation, and shut-down procedures. A description of the equipment used in the process is given. Some theoretical material is presented. (BB)

Effects of temperature on the removal efficiency of KDP crystal during the process of magnetorheological water-dissolution polishing.

PubMed

Zhang, Yifan; Dai, Yifan; Tie, Guipeng; Hu, Hao

2016-10-10

As a kind of important nonlinear optical element, KDP crystal has great demand in the inertial confinement fusion system. Based on the dissolution mechanism of solid materials, the factors that affect the material removal rate of KDP crystal in magnetorheological (MR) water-dissolution polishing are investigated to improve the machining efficiency. It is found that the material removal rate is proportional to the product of the saturation concentration and diffusion coefficient, and the relationship between the removal efficiency and the temperature meets the unilateral Gaussian function. Polishing experiments are carried out on a magnetorheological finishing (MRF) machine with self-designed MRF fluid heating devices. The experimental results show that practical efficiency-temperature curve is consistent with the theoretical curve, and the maximum machining efficiency increases by about 50% with the rise of temperature from 294 to 302 K. Meanwhile, when the MR fluid temperature is lower than 308 K, the crystal surface quality and surface roughness in different processing temperatures have no remarkable difference with constant crystal temperature (294 K). This research indicates that it is feasible to drastically improve KDP crystal MRF efficiency by controlling the processing temperature.

Material removal characteristics of orthogonal velocity polishing tool for efficient fabrication of CVD SiC mirror surfaces

NASA Astrophysics Data System (ADS)

Seo, Hyunju; Han, Jeong-Yeol; Kim, Sug-Whan; Seong, Sehyun; Yoon, Siyoung; Lee, Kyungmook; Lee, Haengbok

2015-09-01

Today, CVD SiC mirrors are readily available in the market. However, it is well known to the community that the key surface fabrication processes and, in particular, the material removal characteristics of the CVD SiC mirror surface varies sensitively depending on the shop floor polishing and figuring variables. We investigated the material removal characteristics of CVD SiC mirror surfaces using a new and patented polishing tool called orthogonal velocity tool (OVT) that employs two orthogonal velocity fields generated simultaneously during polishing and figuring machine runs. We built an in-house OVT machine and its operating principle allows for generation of pseudo Gaussian shapes of material removal from the target surface. The shapes are very similar to the tool influence functions (TIFs) of other polishing machine such as IRP series polishing machines from Zeeko. Using two CVD SiC mirrors of 150 mm in diameter and flat surface, we ran trial material removal experiments over the machine run parameter ranges from 12.901 to 25.867 psi in pressure, 0.086 m/sec to 0.147 m/sec in tool linear velocity, and 5 to 15 sec in dwell time. An in-house developed data analysis program was used to obtain a number of Gaussian shaped TIFs and the resulting material removal coefficient varies from 3.35 to 9.46 um/psi hour m/sec with the mean value to 5.90 ± 1.26(standard deviation). We report the technical details of the new OVT machine, of the data analysis program, of the experiments and the results together with the implications to the future development of the OVT machine and process for large CVD SiC mirror surfaces.

Grinding model and material removal mechanism of medical nanometer zirconia ceramics.

PubMed

Zhang, Dongkun; Li, Changhe; Jia, Dongzhou; Wang, Sheng; Li, Runze; Qi, Xiaoxiao

2014-01-01

Many patents have been devoted to developing medical nanometer zirconia ceramic grinding techniques that can significantly improve both workpiece surface integrity and grinding quality. Among these patents is a process for preparing ceramic dental implants with a surface for improving osseo-integration by sand abrasive finishing under a jet pressure of 1.5 bar to 8.0 bar and with a grain size of 30 µm to 250 µm. Compared with other materials, nano-zirconia ceramics exhibit unmatched biomedical performance and excellent mechanical properties as medical bone tissue and dentures. The removal mechanism of nano-zirconia materials includes brittle fracture and plastic removal. Brittle fracture involves crack formation, extension, peeling, and chipping to completely remove debris. Plastic removal is similar to chip formation in metal grinding, including rubbing, ploughing, and the formation of grinding debris. The materials are removed in shearing and chipping. During brittle fracture, the grinding-led transverse and radial extension of cracks further generate local peeling of blocks of the material. In material peeling and removal, the mechanical strength and surface quality of the workpiece are also greatly reduced because of crack extension. When grinding occurs in the plastic region, plastic removal is performed, and surface grinding does not generate grinding fissures and surface fracture, producing clinically satisfactory grinding quality. With certain grinding conditions, medical nanometer zirconia ceramics can be removed through plastic flow in ductile regime. In this study, we analyzed the critical conditions for the transfer of brittle and plastic removal in nano-zirconia ceramic grinding as well as the high-quality surface grinding of medical nanometer zirconia ceramics by ELID grinding.

Supercritical fluid extraction

DOEpatents

Wai, Chien M.; Laintz, Kenneth

1994-01-01

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

A new reactive atom plasma technology (RAPT) for precision machining: the etching of ULE optical surfaces

NASA Astrophysics Data System (ADS)

Fanara, Carlo; Shore, Paul; Nicholls, John R.; Lyford, Nicholas; Sommer, Phil; Fiske, Peter

2006-06-01

The next generation of 30-100 metre diameter extremely large telescopes (ELTs) requires large numbers of hexagonal primary mirror segments. As part of the Basic Technology programme run jointly by UCL and Cranfield University, a reactive atomic plasma technology (RAP(tm)) emerged from the US Lawrence Livermore National Laboratory (LLNL), is employed for the finishing of these surfaces. Results are presented on this novel etching technology. The Inductively Coupled Plasma (ICP) operated at atmospheric pressure using argon, activates the chemical species injected through its centre and promotes the fluorine-based chemical reactions at the surface. Process assessment trials on Ultra Low Expansion (ULE(tm)) plates, previously ground at high material removal rates, have been conducted. The quality of the surfaces produced on these samples using the RAP process are discussed. Substantial volumetric material removal rates of up to 0.446(21) mm 3/s at the highest process speed (1,200 mm/min) were found to be possible without pre-heating the substrate. The influences of power transfer, process speed and gas concentration on the removal rates have been determined. The suitability of the RAP process for revealing and removing sub-surface damage induced by high removal rate grinding is discussed. The results on SiC samples are reported elsewhere in this conference.

Influence of the chain length of surfactant in the modification of zeolites and clays. Removal of atrazine from water solutions.

PubMed

Toledo-Jaldin, Helen Paola; Blanco-Flores, Alien; Sánchez-Mendieta, Víctor; Martín-Hernández, Osnieski

2017-08-30

Removal potentials of a surfactant modified zeolite (SMZ) and clay (SMC) for atrazine adsorption were evaluated. Materials were modified with hexadecyl trimethyl ammonium bromide (HDTMA-Br) and benzyl octadecyl dimethyl ammonium (BODA) chloride considering the critical micellar concentration (CMC) of each one (0.94 and 0.041 meq/L, respectively). The influence of the surfactant was analyzed in detail, particularly the formation of surfactant layers (complete or partial) connected with the length of the surfactant tail (16 and 18 methyl groups or number of carbons in the chain). Raw materials were characterized by XRD and Fourier transform infrared spectroscopy (FTIR), SMZ and SMC were analyzed by FTIR. Results obtained from kinetic adsorption experiments shown that equilibrium time is less for materials modified with HDTMA (8 h) than materials with BODA (10 and 12 h). Materials modified with the largest chain surfactant (BODA) showed more resistance to atrazine masse transference. The chemisorption was presented in the adsorption mechanisms of atrazine and adsorbent materials. Based on the results of adsorption isotherms Langmuir isotherms showed the better correlation coefficients value. The q max is greater for materials modified with BODA (0.9232 and 4.2448 mg/g) than for materials modified with HDTMA (0.6731 and 3.9121 mg/g). Therefore, SMZ and SMC modified with the largest chain surfactant has more affinity for the pesticide. The removal process at high concentration of atrazine depends of the partition process but at lower concentration, it occurs not only by this process but also by absorption process.

Laser-driven hydrothermal process studied with excimer laser pulses

NASA Astrophysics Data System (ADS)

Mariella, Raymond; Rubenchik, Alexander; Fong, Erika; Norton, Mary; Hollingsworth, William; Clarkson, James; Johnsen, Howard; Osborn, David L.

2017-08-01

Previously, we discovered [Mariella et al., J. Appl. Phys. 114, 014904 (2013)] that modest-fluence/modest-intensity 351-nm laser pulses, with insufficient fluence/intensity to ablate rock, mineral, or concrete samples via surface vaporization, still removed the surface material from water-submerged target samples with confinement of the removed material, and then dispersed at least some of the removed material into the water as a long-lived suspension of nanoparticles. We called this new process, which appears to include the generation of larger colorless particles, "laser-driven hydrothermal processing" (LDHP) [Mariella et al., J. Appl. Phys. 114, 014904 (2013)]. We, now, report that we have studied this process using 248-nm and 193-nm laser light on submerged concrete, quartzite, and obsidian, and, even though light at these wavelengths is more strongly absorbed than at 351 nm, we found that the overall efficiency of LDHP, in terms of the mass of the target removed per Joule of laser-pulse energy, is lower with 248-nm and 193-nm laser pulses than with 351-nm laser pulses. Given that stronger absorption creates higher peak surface temperatures for comparable laser fluence and intensity, it was surprising to observe reduced efficiencies for material removal. We also measured the nascent particle-size distributions that LDHP creates in the submerging water and found that they do not display the long tail towards larger particle sizes that we had observed when there had been a multi-week delay between experiments and the date of measuring the size distributions. This is consistent with transient dissolution of the solid surface, followed by diffusion-limited kinetics of nucleation and growth of particles from the resulting thin layer of supersaturated solution at the sample surface.

A study of material removal during magnetorheological finishing. 1998 summer research program for high school juniors at the Univ. of Rochester`s Laboratory for Laser Energetics: Student research reports

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

Hubregsen, J.

1999-03-01

In the process of optical polishing, a new method has been developed called Magnetorheological Finishing, or MRF. This process utilizes both mechanical and chemical effects to remove material during polishing. To more fully understand the fundamental mechanisms of MR polishing the authors have successfully separated mechanical scratching from chemical softening in glass polishing with MRF by removing the water from the MR fluid. The addition of water initiates the chemical effects by hydrating the glass surface and changing the amplitude of the scratches. In addition, this study has found that the mechanical removal by scratching is related to the hardnessmore » of the magnetic carbonyl iron particles, and the hardness and type of the glass being polished.« less

Leaching of nitroso rubber material removes uncured polymer

NASA Technical Reports Server (NTRS)

Bratfisch, W. A.; Gonzalez, R.

1972-01-01

New leaching process removes uncured polymer from nitroso rubber, elastomer used in presence of nitrogen tetroxide. Uncured portion is removed by controlled soaking of polymer slab in Freon TF. Leaching with Freon TF prevents nitroso rubber from adhering to adjoining surfaces and limiting its usefulness in either static or dynamic applications.

Advanced Coating Removal Techniques

NASA Technical Reports Server (NTRS)

Seibert, Jon

2006-01-01

An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid nitrogen operations include cutting of both soft and hard materials. While the laser will not cut materials, it can be used to roughen surfaces and to remove other materials from the substrate including oil, grease, and mold. The space program can benefit from several of these applications with the need for precise removal of coatings and other organic compounds in areas adjacent to sensitive space flight hardware. Significant advantages are evident when comparing liquid nitrogen and laser removal operations over current techniques of media blasting and sanding.

Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline

DOEpatents

Baker, Eddie G.; Elliott, Douglas C.

1993-01-01

The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compouns as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

Method of upgrading oils containing hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline

DOEpatents

Baker, E.G.; Elliott, D.C.

1993-01-19

The present invention is a multi-stepped method of converting an oil which is produced by various biomass and coal conversion processes and contains primarily single and multiple ring hydroxyaromatic hydrocarbon compounds to highly aromatic gasoline. The single and multiple ring hydroxyaromatic hydrocarbon compounds in a raw oil material are first deoxygenated to produce a deoxygenated oil material containing single and multiple ring aromatic compounds. Then, water is removed from the deoxygenated oil material. The next step is distillation to remove the single ring aromatic compounds as gasoline. In the third step, the multiple ring aromatics remaining in the deoxygenated oil material are cracked in the presence of hydrogen to produce a cracked oil material containing single ring aromatic compounds. Finally, the cracked oil material is then distilled to remove the single ring aromatics as gasoline.

An atomic-scale and high efficiency finishing method of zirconia ceramics by using magnetorheological finishing

NASA Astrophysics Data System (ADS)

Luo, Hu; Guo, Meijian; Yin, Shaohui; Chen, Fengjun; Huang, Shuai; Lu, Ange; Guo, Yuanfan

2018-06-01

Zirconia ceramics is a valuable crucial material for fabricating functional components applied in aerospace, biology, precision machinery, military industry and other fields. However, the properties of its high brittleness and high hardness could seriously reduce its finishing efficiency and surface quality by conventional processing technology. In this work, we present a high efficiency and high-quality finishing process by using magnetorheological finishing (MRF), which employs the permanent magnetic yoke with straight air gap as excitation unit. The sub-nanoscale surface roughness and damage free surface can be obtained after magnetorheological finishing. The XRD results and SEM morphologies confirmed that the mechanical shear removal with ductile modes are the dominant material removal mechanism for the magnetorheological finishing of zirconia ceramic. With the developed experimental apparatus, the effects of workpiece speed, trough speed and work gap on material removal rate and surface roughness were systematically investigated. Zirconia ceramics finished to ultra-smooth surface with surface roughness less than Ra 1 nm was repeatedly achieved during the parametric experiments. Additionally, the highest material removal rate exceeded 1 mg/min when using diamond as an abrasive particle. Magnetorheological finishing promises to be an adaptable and efficient method for zirconia ceramics finishing.

In-situ method to remove iron and other metals from solution in groundwater down gradient from permeable reactive barrier

DOEpatents

Carpenter, Clay E.; Morrison, Stanley J.

2001-07-03

This invention is directed to a process for treating the flow of anaerobic groundwater through an aquifer with a primary treatment media, preferably iron, and then passing the treated groundwater through a second porous media though which an oxygenated gas is passed in order to oxygenate the dissolved primary treatment material and convert it into an insoluble material thereby removing the dissolved primary treatment material from the groundwater.

Microbial fuel cell treatment of ethanol fermentation process water

DOEpatents

Borole, Abhijeet P [Knoxville, TN

2012-06-05

The present invention relates to a method for removing inhibitor compounds from a cellulosic biomass-to-ethanol process which includes a pretreatment step of raw cellulosic biomass material and the production of fermentation process water after production and removal of ethanol from a fermentation step, the method comprising contacting said fermentation process water with an anode of a microbial fuel cell, said anode containing microbes thereon which oxidatively degrade one or more of said inhibitor compounds while producing electrical energy or hydrogen from said oxidative degradation, and wherein said anode is in electrical communication with a cathode, and a porous material (such as a porous or cation-permeable membrane) separates said anode and cathode.

Polymer functionalized nanocomposites for metals removal from water and wastewater: An overview.

PubMed

Lofrano, Giusy; Carotenuto, Maurizio; Libralato, Giovanni; Domingos, Rute F; Markus, Arjen; Dini, Luciana; Gautam, Ravindra Kumar; Baldantoni, Daniela; Rossi, Marco; Sharma, Sanjay K; Chattopadhyaya, Mahesh Chandra; Giugni, Maurizio; Meric, Sureyya

2016-04-01

Pollution by metal and metalloid ions is one of the most widespread environmental concerns. They are non-biodegradable, and, generally, present high water solubility facilitating their environmental mobilisation interacting with abiotic and biotic components such as adsorption onto natural colloids or even accumulation by living organisms, thus, threatening human health and ecosystems. Therefore, there is a high demand for effective removal treatments of heavy metals, making the application of adsorption materials such as polymer-functionalized nanocomposites (PFNCs), increasingly attractive. PFNCs retain the inherent remarkable surface properties of nanoparticles, while the polymeric support materials provide high stability and processability. These nanoparticle-matrix materials are of great interest for metals and metalloids removal thanks to the functional groups of the polymeric matrixes that provide specific bindings to target pollutants. This review discusses PFNCs synthesis, characterization and performance in adsorption processes as well as the potential environmental risks and perspectives. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved force prediction model for grinding Zerodur based on the comprehensive material removal mechanism.

PubMed

Sun, Guoyan; Zhao, Lingling; Zhao, Qingliang; Gao, Limin

2018-05-10

There have been few investigations dealing with the force model on grinding brittle materials. However, the dynamic material removal mechanisms have not yet been sufficiently explicated through the grain-workpiece interaction statuses while considering the brittle material characteristics. This paper proposes an improved grinding force model for Zerodur, which contains ductile removal force, brittle removal force, and frictional force, corresponding to the ductile and brittle material removal phases, as well as the friction process, respectively. The critical uncut chip thickness a gc of brittle-ductile transition and the maximum uncut chip thickness a gmax of a single abrasive grain are calculated to identify the specified material removal mode, while the comparative result between a gmax and a gc can be applied to determine the selection of effective grinding force components. Subsequently, indentation fracture tests are carried out to acquire accurate material mechanical properties of Zerodur in establishing the brittle removal force model. Then, the experiments were conducted to derive the coefficients in the grinding force prediction model. Simulated through this model, correlations between the grinding force and grinding parameters can be predicted. Finally, three groups of grinding experiments are carried out to validate the mathematical grinding force model. The experimental results indicate that the improved model is capable of predicting the realistic grinding force accurately with the relative mean errors of 6.04% to the normal grinding force and 7.22% to the tangential grinding force, respectively.

Investigations of Effect of Rotary EDM Electrode on Machining Performance of Al6061 Alloy

NASA Astrophysics Data System (ADS)

Robinson Smart, D. S.; Jenish Smart, Joses; Periasamy, C.; Ratna Kumar, P. S. Samuel

2018-04-01

Electric Discharge Machining is an essential process which is being used for machining desired shape using electrical discharges which creates sparks. There will be electrodes subjected to electric voltage and which are separated by a dielectric liquid. Removing of material will be due to the continuous and rapid current discharges between two electrodes.. The spark is very carefully controlled and localized so that it only affects the surface of the material. Usually in order to prevent the defects which are arising due to the conventional machining, the Electric Discharge Machining (EDM) machining is preferred. Also intricate and complicated shapes can be machined effectively by use of Electric Discharge Machining (EDM). The EDM process usually does not affect the heat treat below the surface. This research work focus on the design and fabrication of rotary EDM tool for machining Al6061alloy and investigation of effect of rotary tool on surface finish, material removal rate and tool wear rate. Also the effect of machining parameters of EDM such as pulse on & off time, current on material Removal Rate (MRR), Surface Roughness (SR) and Electrode wear rate (EWR) have studied. Al6061 alloy can be used for marine and offshore applications by reinforcing some other elements. The investigations have revealed that MRR (material removal rate), surface roughness (Ra) have been improved with the reduction in the tool wear rate (TWR) when the tool is rotating instead of stationary. It was clear that as rotary speed of the tool is increasing the material removal rate is increasing with the reduction of surface finish and tool wear rate.

Novel cavitation fluid jet polishing process based on negative pressure effects.

PubMed

Chen, Fengjun; Wang, Hui; Tang, Yu; Yin, Shaohui; Huang, Shuai; Zhang, Guanghua

2018-04-01

Traditional abrasive fluid jet polishing (FJP) is limited by its high-pressure equipment, unstable material removal rate, and applicability to ultra-smooth surfaces because of the evident air turbulence, fluid expansion, and a large polishing spot in high-pressure FJP. This paper presents a novel cavitation fluid jet polishing (CFJP) method and process based on FJP technology. It can implement high-efficiency polishing on small-scale surfaces in a low-pressure environment. CFJP uses the purposely designed polishing equipment with a sealed chamber, which can generate a cavitation effect in negative pressure environment. Moreover, the collapse of cavitation bubbles can spray out a high-energy microjet and shock wave to enhance the material removal. Its feasibility is verified through researching the flow behavior and the cavitation results of the negative pressure cavitation machining of pure water in reversing suction flow. The mechanism is analyzed through a computational fluid dynamics simulation. Thus, its cavitation and surface removal mechanisms in the vertical CFJP and inclined CFJP are studied. A series of polishing experiments on different materials and polishing parameters are conducted to validate its polishing performance compared with FJP. The maximum removal depth increases, and surface roughness gradually decreases with increasing negative outlet pressures. The surface becomes smooth with the increase of polishing time. The experimental results confirm that the CFJP process can realize a high material removal rate and smooth surface with low energy consumption in the low-pressure environment, together with compatible surface roughness to FJP. Copyright © 2017 Elsevier B.V. All rights reserved.

Accurate Micro-Tool Manufacturing by Iterative Pulsed-Laser Ablation

NASA Astrophysics Data System (ADS)

Warhanek, Maximilian; Mayr, Josef; Dörig, Christian; Wegener, Konrad

2017-12-01

Iterative processing solutions, including multiple cycles of material removal and measurement, are capable of achieving higher geometric accuracy by compensating for most deviations manifesting directly on the workpiece. Remaining error sources are the measurement uncertainty and the repeatability of the material-removal process including clamping errors. Due to the lack of processing forces, process fluids and wear, pulsed-laser ablation has proven high repeatability and can be realized directly on a measuring machine. This work takes advantage of this possibility by implementing an iterative, laser-based correction process for profile deviations registered directly on an optical measurement machine. This way efficient iterative processing is enabled, which is precise, applicable for all tool materials including diamond and eliminates clamping errors. The concept is proven by a prototypical implementation on an industrial tool measurement machine and a nanosecond fibre laser. A number of measurements are performed on both the machine and the processed workpieces. Results show production deviations within 2 μm diameter tolerance.

Damascene fabrication of nonplanar microcoils

DOEpatents

Adams, David P.; Vasile, Michael J.

2003-06-17

A process for fabricating coils using a Damascene process uses a curved substrate having a surface extending along and about an axis made of a first material. A groove is formed in the curved surface along and around said axis, and the groove is filled with a second material that is different from the first material to form a coil of second material in said first material. Excess second material is then removed from the surface of the first material, leaving the coil of second material in the groove.

Efficient Removal of Arsenic and Antimony During Blast Furnace Smelting of Lead-Containing Materials

NASA Astrophysics Data System (ADS)

Dosmukhamedov, Nurlan; Kaplan, Valery

2017-02-01

The efficient removal of impurities, As and Sb, from recycled lead-containing materials is a key issue in the selection of the appropriate smelting technology for projects involving metal reuse. Volatilization of impurities such as As and Sb should occur as early as possible in the process, and preferably within the smelting furnace, so that they do not contaminate the industrial environment nor interfere with the operation of downstream equipment. Using of copper-zinc concentrates in the blast furnace process for recycling lead-containing materials achieves: (1) high copper extraction to matte; (2) high lead extraction to lead bullion; and (3) high zinc extraction to slag, while at the same time producing a more efficient volatilization of As and Sb. Based on both laboratory and industrial data and thermodynamic considerations, the advantages of this blast furnace process for the treatment of recycled lead-containing materials are discussed.

Removal of mercury from an alumina refinery aqueous stream.

PubMed

Mullett, Mark; Tardio, James; Bhargava, Suresh; Dobbs, Charles

2007-06-01

Digestion condensate is formed as a by-product of the alumina refinery digestion process. The solution exhibits a high pH and is chemically reducing, containing many volatile species such as water, volatile organics, ammonia, and mercury. Because digestion condensate is chemically unique, an innovative approach was required to investigate mercury removal. The mercury capacity and adsorption kinetics were investigated using a number of materials including gold, silver and sulphur impregnated silica and a silver impregnated carbon. The results were compared to commercial sorbents, including extruded and powdered virgin activated carbons and a sulphur impregnated mineral. Nano-gold supported on silica (88% removal under batch conditions and 95% removal under flow conditions) and powdered activated carbon (91% under batch conditions and 98% removal under flow conditions) were the most effective materials investigated. The silver and sulphur impregnated materials were unstable in digestion condensate under the test conditions used.

Electrolytic decontamination of conductive materials for hazardous waste management

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

Wedman, D.E.; Martinez, H.E.; Nelson, T.O.

1996-12-31

Electrolytic removal of plutonium and americium from stainless steel and uranium surfaces has been demonstrated. Preliminary experiments were performed on the electrochemically based decontamination of type 304L stainless steel in sodium nitrate solutions to better understand the metal removal effects of varying cur-rent density, pH, and nitrate concentration parameters. Material removal rates and changes in surface morphology under these varying conditions are reported. Experimental results indicate that an electropolishing step before contamination removes surface roughness, thereby simplifying later electrolytic decontamination. Sodium nitrate based electrolytic decontamination produced the most uniform stripping of material at low to intermediate pH and at sodiummore » nitrate concentrations of 200 g L{sup -1} and higher. Stirring was also observed to increase the uniformity of the stripping process.« less

Evaluation of layered zinc hydroxide nitrate and zinc/nickel double hydroxide salts in the removal of chromate ions from solutions

NASA Astrophysics Data System (ADS)

de Oliveira, Henrique Bortolaz; Wypych, Fernando

2016-11-01

Layered zinc hydroxide nitrate (ZnHN) and Zn/Ni layered double hydroxide salts were synthesized and used to remove chromate ions from solutions at pH 8.0. The materials were characterized by many instrumental techniques before and after chromate ion removal. ZnHN decomposed after contact with the chromate solution, whereas the layered structure of Zn/Ni hydroxide nitrate (Zn/NiHN) and Zn/Ni hydroxide acetate (Zn/NiHA) remained their layers intact after the topotactic anionic exchange reaction, only changing the basal distances. ZnHN, Zn/NiHN, and Zn/NiHA removed 210.1, 144.8, and 170.1 mg of CrO42-/g of material, respectively. Although the removal values obtained for Zn/NiHN and Zn/NiHA were smaller than the values predicted for the ideal formulas of the solids (194.3 and 192.4 mg of CrO42-/g of material, respectively), the measured capacities were higher than the values achieved with many materials reported in the literature. Kinetic experiments showed the removal reaction was fast. To facilitate the solid/liquid separation process after chromium removal, Zn/Ni layered double hydroxide salts with magnetic supports were also synthesized, and their ability to remove chromate was evaluated.

Controlled core removal from a D-shaped optical fiber.

PubMed

Markos, Douglas J; Ipson, Benjamin L; Smith, Kevin H; Schultz, Stephen M; Selfridge, Richard H; Monte, Thomas D; Dyott, Richard B; Miller, Gregory

2003-12-20

The partial removal of a section of the core from a continuous D-shaped optical fiber is presented. In the core removal process, selective chemical etching is used with hydrofluoric (HF) acid. A 25% HF acid solution removes the cladding material above the core, and a 5% HF acid solution removes the core. A red laser with a wavelength of 670 nm is transmitted through the optical fiber during the etching. The power transmitted through the optical fiber is correlated to the etch depth by scanning electron microscope imaging. The developed process provides a repeatable method to produce an optical fiber with a specific etch depth.

Feed gas contaminant removal in ion transport membrane systems

DOEpatents

Underwood, Richard Paul [Allentown, PA; Makitka, III, Alexander; Carolan, Michael Francis [Allentown, PA

2012-04-03

An oxygen ion transport membrane process wherein a heated oxygen-containing gas having one or more contaminants is contacted with a reactive solid material to remove the one or more contaminants. The reactive solid material is provided as a deposit on a support. The one or more contaminant compounds in the heated oxygen-containing gas react with the reactive solid material. The contaminant-depleted oxygen-containing gas is contacted with a membrane, and oxygen is transported through the membrane to provide transported oxygen.

Electro-Fenton for control and removal of micropollutants - process optimization and energy efficiency.

PubMed

Mousset, E; Wang, Z; Lefebvre, O

2016-11-01

The removal of micropollutants is an important environmental and health issue. Electro-Fenton offers an electrochemical advanced treatment that is particularly effective for the breakdown of aromatic contaminants. Due to the wide variety of chemicals, it is preferable to analyze model contaminants, such as phenol, when optimizing and assessing the efficacy of a novel treatment process. In this study, we therefore made use of innovative types of electrode material and optimized operating parameters (current density and aeration rate) for the removal of phenol by electro-Fenton, with a view to maximize the energy efficiency of the process. By determining the best current density (1.25 mA cm -2 ), frequency of aeration (continuous) and by using a boron-doped diamond (BDD) anode, it was possible to achieve over 98.5% phenol (1 mM) removal within 1.5 h. BDD further outcompeted platinum as anode material in terms of mineralization rate and yield, and displayed low energy consumption of 0.08 kWh (g-TOC) -1 , about one order of magnitude lower than other advanced oxidation processes, such as UV/TiO 2 and UV/O 3 . Furthermore, a carbon cloth anode proved even more cost-effective than BDD if the end goal is the removal of phenol by electro-Fenton instead of complete mineralization.

Advantages offered by high average power picosecond lasers

NASA Astrophysics Data System (ADS)

Moorhouse, C.

2011-03-01

As electronic devices shrink in size to reduce material costs, device size and weight, thinner material thicknesses are also utilized. Feature sizes are also decreasing, which is pushing manufacturers towards single step laser direct write process as an attractive alternative to conventional, multiple step photolithography processes by eliminating process steps and the cost of chemicals. The fragile nature of these thin materials makes them difficult to machine either mechanically or with conventional nanosecond pulsewidth, Diode Pumped Solids State (DPSS) lasers. Picosecond laser pulses can cut materials with reduced damage regions and selectively remove thin films due to the reduced thermal effects of the shorter pulsewidth. Also, the high repetition rate allows high speed processing for industrial applications. Selective removal of thin films for OLED patterning, silicon solar cells and flat panel displays is discussed, as well as laser cutting of transparent materials with low melting point such as Polyethylene Terephthalate (PET). For many of these thin film applications, where low pulse energy and high repetition rate are required, throughput can be increased by the use of a novel technique to using multiple beams from a single laser source is outlined.

Erosion of pelvicol used in sacrocolpopexy.

PubMed

Mukati, Marium S; Shobeiri, S Abbas

2013-01-01

Biologic graft materials are used more frequently in pelvic reconstructive surgeries. We describe here the complete process of removal of such a biologic graft in the office. We report a case of a 69-year-old woman with pig dermal graft erosion 1 year after placement. The patient presented with complaints of vaginal discharge. Upon examination, the graft material was seen eroding through the vaginal apex. The pig tissue was removed whole and intact in the office without complications. Transvaginal removal of pig tissue in the office relieved the patient's symptoms.

Disposable and removable nucleic acid extraction and purification cartridges for automated flow-through systems

DOEpatents

Regan, John Frederick

2014-09-09

Removable cartridges are used on automated flow-through systems for the purpose of extracting and purifying genetic material from complex matrices. Different types of cartridges are paired with specific automated protocols to concentrate, extract, and purifying pathogenic or human genetic material. Their flow-through nature allows large quantities sample to be processed. Matrices may be filtered using size exclusion and/or affinity filters to concentrate the pathogen of interest. Lysed material is ultimately passed through a filter to remove the insoluble material before the soluble genetic material is delivered past a silica-like membrane that binds the genetic material, where it is washed, dried, and eluted. Cartridges are inserted into the housing areas of flow-through automated instruments, which are equipped with sensors to ensure proper placement and usage of the cartridges. Properly inserted cartridges create fluid- and air-tight seals with the flow lines of an automated instrument.

Removal of copper ions from aqueous solutions by a steel-making by-product.

PubMed

López, F A; Martín, M I; Pérez, C; López-Delgado, A; Alguacil, F J

2003-09-01

A study is made of the use of a steel-making by-product (rolling mill scale) as a material for removing Cu(2+) ions from aqueous solutions. The influence of contact time, initial copper ion concentration and temperature on removal capability is considered. The removal of Cu(2+) ions from an aqueous solution involves two processes: on the one hand, the adsorption of Cu(2+) ions on the surface of mill scale due to the iron oxides present in the latter; and on the other hand, the cementation of Cu(2+) onto metallic iron contained in the mill scale. Rolling mill scale is seen to be an effective material for the removal of copper ions from aqueous solutions.

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

Qiusheng, Y., E-mail: qsyan@gdut.edu.cn; Senkai, C., E-mail: senkite@sina.com; Jisheng, P., E-mail: panjisheng@gdut.edu.cn

Different machining processes were used in the single crystal SiC wafer machining. SEM was used to observe the surface morphology and a cross-sectional cleavages microscopy method was used for subsurface cracks detection. Surface and subsurface cracks characteristics of single crystal SiC wafer in abrasive machining were analysed. The results show that the surface and subsurface cracks system of single crystal SiC wafer in abrasive machining including radial crack, lateral crack and the median crack. In lapping process, material removal is dominated by brittle removal. Lots of chipping pits were found on the lapping surface. With the particle size becomes smaller,more » the surface roughness and subsurface crack depth decreases. When the particle size was changed to 1.5µm, the surface roughness Ra was reduced to 24.0nm and the maximum subsurface crack was 1.2µm. The efficiency of grinding is higher than lapping. Plastic removal can be achieved by changing the process parameters. Material removal was mostly in brittle fracture when grinding with 325# diamond wheel. Plow scratches and chipping pits were found on the ground surface. The surface roughness Ra was 17.7nm and maximum subsurface crack depth was 5.8 µm. When grinding with 8000# diamond wheel, the material removal was in plastic flow. Plastic scratches were found on the surface. A smooth surface of roughness Ra 2.5nm without any subsurface cracks was obtained. Atomic scale removal was possible in cluster magnetorheological finishing with diamond abrasive size of 0.5 µm. A super smooth surface eventually obtained with a roughness of Ra 0.4nm without any subsurface crack.« less

Method to Improve Indium Bump Bonding via Indium Oxide Removal Using a Multi-Step Plasma Process

NASA Technical Reports Server (NTRS)

Dickie, Matthew R. (Inventor); Nikzad, Shouleh (Inventor); Greer, H. Frank (Inventor); Jones, Todd J. (Inventor); Vasquez, Richard P. (Inventor); Hoenk, Michael E. (Inventor)

2012-01-01

A process for removing indium oxide from indium bumps in a flip-chip structure to reduce contact resistance, by a multi-step plasma treatment. A first plasma treatment of the indium bumps with an argon, methane and hydrogen plasma reduces indium oxide, and a second plasma treatment with an argon and hydrogen plasma removes residual organics. The multi-step plasma process for removing indium oxide from the indium bumps is more effective in reducing the oxide, and yet does not require the use of halogens, does not change the bump morphology, does not attack the bond pad material or under-bump metallization layers, and creates no new mechanisms for open circuits.

Ion processing element with composite media

DOEpatents

Mann, Nick R.; Tranter, Troy J.; Todd, Terry A.; Sebesta, Ferdinand

2003-02-04

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Ion processing element with composite media

DOEpatents

Mann, Nick R [Blackfoot, ID; Tranter, Troy J [Idaho Falls, ID; Todd, Terry A [Aberdeen, ID; Sebesta, Ferdinand [Prague, CZ

2009-03-24

An ion processing element employing composite media disposed in a porous substrate, for facilitating removal of selected chemical species from a fluid stream. The ion processing element includes a porous fibrous glass substrate impregnated by composite media having one or more active components supported by a matrix material of polyacrylonitrile. The active components are effective in removing, by various mechanisms, one or more constituents from a fluid stream passing through the ion processing element. Due to the porosity and large surface area of both the composite medium and the substrate in which it is disposed, a high degree of contact is achieved between the active component and the fluid stream being processed. Further, the porosity of the matrix material and the substrate facilitates use of the ion processing element in high volume applications where it is desired to effectively process a high volume flows.

Processes for Removal and Immobilization of 14C, 129I, and 85Kr

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

Strachan, Denis M.; Bryan, Samuel A.; Henager, Charles H.

2009-10-05

This is a white paper covering the results of a literature search and preliminary experiments on materials and methods to remove and immobilize gaseous radionuclided that come from the reprocessing of spent nuclear fuel.

Atomic Oxygen Treatment as a Method of Recovering Smoke Damaged Paintings. Revised

NASA Technical Reports Server (NTRS)

Rutledge, Sharon K.; Banks, Bruce A.; Forkapa, Mark; Stueber, Thomas; Sechkar, Edward; Malinowski, Kevin

1999-01-01

A noncontact technique is described that uses atomic oxygen, generated under low pressure in the presence of nitrogen, to remove soot and charred varnish from the surface of a painting. The process, which involves surface oxidation, permits control of the amount of surface material removed. The effectiveness of the process was evaluated by reflectance measurements from selected areas made during the removal of soot from acrylic gesso, ink on paper, and varnished oil paint substrates. For the latter substrate, treatment also involved the removal of damaged varnish and paint binder from the surface.

Final Report on NASA Portable Laser Coating Removal Systems Field Demonstrations and Testing

NASA Technical Reports Server (NTRS)

Rothgeb, Matthew J; McLaughlin, Russell L.

2008-01-01

Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment, small parts and flight components result in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the Occupational Safety and Health Administration (OSHA) reduced the permissible exposure limit (PEL) for hexavalent chromium (CrVI) from 52 to 5 micrograms per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in numerous pretreatment and primer coatings used within the Space Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient, and environmentally preferable manner. The use of laser energy to prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation, and non destructive evaluation (NDE) is a relatively new application of the technology that has been proven to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The novel process eliminates VOCs and blast media and captures the removed coatings with an integrated vacuum system. This means that the only waste generated are the coatings that are removed, resulting in an overall cleaner process. The development of a Portable Laser Coating Removal System (PLCRS) started as the goal of a Joint Group on Pollution Prevention (JG-PP) project, led by the Air Force, where several types of lasers in several configurations were thoroughly evaluated. Following this project, NASA decided to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, between 40 and 500 Watts, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation.

Purifying Water by Imbibition

NASA Technical Reports Server (NTRS)

Lawton, E. A.

1986-01-01

Concept for purifying water uses absorbent material to remove organic substances. Entire bulk of material employed, not just surface. Proposed purification process uses inexpensive equipment and low energy. Material is methyl acrylate polymer. Material cheap and regenerated by rinsing with methanol or by allowing absorbed compounds to evaporate from it.

Recent advances based on the synergetic effect of adsorption for removal of dyes from waste water using photocatalytic process.

PubMed

Natarajan, Subramanian; Bajaj, Hari C; Tayade, Rajesh J

2018-03-01

The problem of textile dye pollution has been addressed by various methods, mainly physical, chemical, biological, and acoustical. These methods mainly separate and/or remove the dye present in water. Recently, advanced oxidation processes (AOP) have been focused for removal of dye from waste water due to their advantages such as ecofriendly, economic and capable to degrade many dyes or organic pollutant present in water. Photocatalysis is one of the advance oxidation processes, mainly carried out under irradiation of light and suitable photocatalytic materials. The photocatalytic activity of the photocatalytic materials mainly depends on the band gap, surface area, and generation of electron-hole pair for degradation dyes present in water. It has been observed that the surface area plays a major role in photocatalytic degradation of dyes, by providing higher surface area, which leads to the higher adsorption of dye molecule on the surface of photocatalyst and enhances the photocatalytic activity. This present review discusses the synergic effect of adsorption of dyes on the photocatalytic efficiency of various nanostructured high surface area photocatalysts. In addition, it also provides the properties of the water polluting dyes, their mechanism and various photocatalytic materials; and their morphology used for the dye degradation under irradiation of light along with the future prospects of highly adsorptive photocatalytic material and their application in photocatalytic removal of dye from waste water. Copyright © 2017. Published by Elsevier B.V.

Extraction of metals and/or metalloids from acidic media using supercritical fluids and salts

DOEpatents

Wai, Chien M.; Smart, Neil G.; Lin, Yuehe

1998-01-01

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent is described. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

US Navy incurs ongoing asbestos removal costs

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

Barber, J.

1983-07-04

Asbestos insulation removal from the Philadelphia Naval Shipyard and a Coast Guard facility at Fort Totten, Queens could cost the Navy over $400 million by the time all asbestos hazards are identified and removed. Much of the cost is due to equipment shutdown during the process and the handling and disposal of asbestos material. Concern over health hazards from exposure to asbestos and recent lawsuits claiming damage prompted the removal. (DCK)

WORKSHOP ON THE DESIGN AND OPERATION OF ADSORPTIVE MEDIA PROCESSES FOR THE REMOVAL OF ARSENIC FROM DRINKING WATER - CD OF PPT PRESENTATIONS

EPA Science Inventory

Presentation material from the Workshop on the Design and Operation of the Adsorptive Media Process for the Removal of Arsenic from Drinking Water. To request a copy of this CD contact Tom Sorg, USEPA, email: sorg.thomas@epa.gov Phone: 513 569-7370 or Fax: 513 569-7172.

Preparation and performance study of MgFe2O4/metal-organic framework composite for rapid removal of organic dyes from water

NASA Astrophysics Data System (ADS)

Tian, Huairu; Peng, Jun; Lv, Tingting; Sun, Chen; He, Hua

2018-01-01

In present study, a stable and magnetic metal-organic framework (MOF) material was synthesized by simple solvothermal method as adsorbent to rapid removal of two organic dyes, the Rhodamine B (RB) and Rhodamine 6G (Rh6G), in water samples. The prepared material showed great characteristics of large surface area (519.86 m2 g-1), excellent magnetic responsivity (35.00 emu g-1) and rapid removal (within 5 min). Maximum adsorption capacities of the magnetic material toward RB and Rh6G were up to 219.78 and 306.75 mg g-1, respectively. Adsorption kinetics suggested the adsorption process met the pseudo-second-order kinetic model. The prepared material could be reused at least 10 times by washing with acetonitrile solution, the relative standard deviation (RSD) of these ten cycles removal efficiency was 4.8%. In conclusion, good chemical inertness, a mechanical/water stability and super-hydrophilicity feature made this MOF a promising adsorbent for targets removal from environmental water sample.

Method for producing catalysis from coal

DOEpatents

Farcasiu, Malvina; Derbyshire, Frank; Kaufman, Phillip B.; Jagtoyen, Marit

1998-01-01

A method for producing catalysts from coal is provided comprising mixing an aqueous alkali solution with the coal, heating the aqueous mixture to treat the coal, drying the now-heated aqueous mixture, reheating the mixture to form carbonized material, cooling the mixture, removing excess alkali from the carbonized material, and recovering the carbonized material, wherein the entire process is carried out in controlled atmospheres, and the carbonized material is a hydrocracking or hydrodehalogenation catalyst for liquid phase reactions. The invention also provides for a one-step method for producing catalysts from coal comprising mixing an aqueous alkali solution with the coal to create a mixture, heating the aqueous mixture from an ambient temperature to a predetermined temperature at a predetermined rate, cooling the mixture, and washing the mixture to remove excess alkali from the treated and carbonized material, wherein the entire process is carried out in a controlled atmosphere.

Method for producing catalysts from coal

DOEpatents

Farcasiu, M.; Derbyshire, F.; Kaufman, P.B.; Jagtoyen, M.

1998-02-24

A method for producing catalysts from coal is provided comprising mixing an aqueous alkali solution with the coal, heating the aqueous mixture to treat the coal, drying the now-heated aqueous mixture, reheating the mixture to form carbonized material, cooling the mixture, removing excess alkali from the carbonized material, and recovering the carbonized material, wherein the entire process is carried out in controlled atmospheres, and the carbonized material is a hydrocracking or hydrodehalogenation catalyst for liquid phase reactions. The invention also provides for a one-step method for producing catalysts from coal comprising mixing an aqueous alkali solution with the coal to create a mixture, heating the aqueous mixture from an ambient temperature to a predetermined temperature at a predetermined rate, cooling the mixture, and washing the mixture to remove excess alkali from the treated and carbonized material, wherein the entire process is carried out in a controlled atmosphere. 1 fig.

Flotation of metal-loaded clay anion exchangers. Part II: the case of arsenates.

PubMed

Lazaridis, N K; Hourzemanoglou, A; Matis, K A

2002-04-01

Hydrotalcite-like materials, or otherwise termed layered double hydroxides, are clays with an ability to remove anions. As they usually are in powder form, these sorbents often present appreciable problems in the solid/liquid separation process following the sorption stage. Sorptive flotation of metal-loaded particles was investigated in this paper, as an alternative two-stage process. In the sorption process, satisfactory removals of arsenic(V) were obtained onto synthetic hydrotalcite particles from water. The effect of some parameters, like the solution ionic strength, concentrations, temperature, etc. was examined. During the second stage of the process, hydrotalcite fine particles were removed from the liquid phase by dispersed-air flotation; various surfactants were tested in relation to the ionic strength of the solution. The combined process of sorptive flotation provides promising results for arsenic removal.

Characterization of Offgas Generated During Calcination of Incinerator Ash Surrogates

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

Wigent, H.L.; Vienna, J.D.; Darab, J.G.

1999-01-28

The Pacific Northwest National Laboratory (PNNL), in cooperation with the Los Alamos National Laboratory (LANL) and Safe Sites of Colorado (SSOC), developed a recommended flowsheet for the processing of plutonium-bearing incinerator ash stored at the Rocky Flats Environmental Technology Site (RFETS) (Lucy et al. 1998). This flowsheet involves a calcination pretreatment step, the purpose of which is to remove carbonaceous material from the incinerator ash. Removal of this material reduced the probability of process upsets, improved product quality, and increases ash waste loading. As part of the continued development of the recommended flowsheet, PNNL performed a series of tests tomore » characterize the offgas generated during the calcination process.« less

Ceria modified activated carbon: an efficient arsenic removal adsorbent for drinking water purification

NASA Astrophysics Data System (ADS)

Sawana, Radha; Somasundar, Yogesh; Iyer, Venkatesh Shankar; Baruwati, Babita

2017-06-01

Ceria (CeO2) coated powdered activated carbon was synthesized by a single step chemical process and demonstrated to be a highly efficient adsorbent for the removal of both As(III) and As(V) from water without any pre-oxidation process. The formation of CeO2 on the surface of powdered activated carbon was confirmed by X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The percentage of Ce in the adsorbent was confirmed to be 3.5 % by ICP-OES. The maximum removal capacity for As(III) and As(V) was found to be 10.3 and 12.2 mg/g, respectively. These values are comparable to most of the commercially available adsorbents. 80 % of the removal process was completed within 15 min of contact time in a batch process. More than 95 % removal of both As(III) and As(V) was achieved within an hour. The efficiency of removal was not affected by change in pH (5-9), salinity, hardness, organic (1-4 ppm of humic acid) and inorganic anions (sulphate, nitrate, chloride, bicarbonate and fluoride) excluding phosphate. Presence of 100 ppm phosphate reduced the removal significantly from 90 to 18 %. The equilibrium adsorption pattern of both As(III) and As(V) fitted well with the Freundlich model with R 2 values 0.99 and 0.97, respectively. The material shows reusability greater than three times in a batch process (arsenic concentration reduced below 10 ppb from 330 ppb) and a life of at least 100 L in a column study with 80 g material when tested under natural hard water (TDS 1000 ppm, pH 7.8, hardness 600 ppm as CaCO3) spiked with 330 ppb of arsenic.

Selective removal of cesium from aqueous solutions with nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell.

PubMed

Ding, Dahu; Lei, Zhongfang; Yang, Yingnan; Feng, Chuanping; Zhang, Zhenya

2014-04-15

A novel nickel (II) hexacyanoferrate (III) functionalized agricultural residue-walnut shell (Ni(II)HCF(III)-WS) was developed to selectively remove cesium ion (Cs(+)) from aqueous solutions. This paper showed the first integral study on Cs(+) removal behavior and waste reduction analysis by using biomass adsorption material. The results indicated that the removal process was rapid and reached saturation within 2h. As a special characteristic of Ni(II)HCF(III)-WS, acidic condition was preferred for Cs(+) removal, which was useful for extending the application scope of the prepared biomass material in treating acidic radioactive liquid waste. The newly developed Ni(II)HCF(III)-WS could selectively remove Cs(+) though the coexisting ions (Na(+) and K(+) in this study) exhibited negative effects. In addition, approximately 99.8% (in volume) of the liquid waste was reduced by using Ni(II)HCF(III)-WS and furthermore 91.9% (in volume) of the spent biomass material (Cs-Ni(II)HCF(III)-WS) was reduced after incineration (at 500°C for 2h). Due to its relatively high distribution coefficient and significant volume reduction, Ni(II)HCF(III)-WS is expected to be a promising material for Cs(+) removal in practice. Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanisms of removal of three widespread pharmaceuticals by two clay materials.

PubMed

Dordio, A V; Miranda, S; Prates Ramalho, J P; Carvalho, A J Palace

2017-02-05

Pharmaceutical residues presence in the environment is among nowadays top emergent environmental issues. For removal of such pollutants, adsorption is a generally efficient process that can be complementary to conventional treatment. Research of cheap, widely available adsorbents may make this process economically attractive. The aim of the present work was to evaluate the capacity of two clay materials (exfoliated vermiculite, LECA) to adsorb gemfibrozil, mefenamic acid and naproxen in lab-scale batch assays. Results show that both adsorbents are able to remove the pharmaceuticals from aqueous medium. Although vermiculite exhibited higher adsorption capacities per unit mass of adsorbent, LECA yielded higher absolute removals of the pharmaceuticals due to the larger mass of adsorbent. Quantum chemistry calculations predicted that the forms of binding of the three molecules to the vermiculite surface are essentially identical, but the adsorption isotherm of naproxen differs substantially from the other two's. The linear forms of the latter impose limits at lower concentrations to the removal efficiencies of these pharmaceuticals by vermiculite, thereby electing LECA as more efficient. Notwithstanding, vermiculite's high specific adsorption capacity and also its much faster adsorption kinetics suggest that there may be some benefits in combining both materials as a composite adsorbent solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Chemistry and Formation of the Beilby Layer During Polishing of Fused Silica Glass

DOE PAGES

Suratwala, Tayyab; Steele, William; Wong, Lana; ...

2015-05-19

The chemical characteristics and the proposed formation mechanisms of the modified surface layer (called the Beilby layer) on polished fused silica glasses are described. Fused silica glass samples were polished using different slurries, polyurethane pads, and at different rotation rates. The concentration profiles of several key contaminants, such as Ce, K, and H, were measured in the near surface layer of the polished samples using Secondary Ion Mass Spectroscopy (SIMS). The penetration of K, originating from KOH used for pH control during polishing, decreased with increase in polishing material removal rate. In contrast, penetration of the Ce and H increasedmore » with increase in polishing removal rate. In addition, Ce penetration was largely independent of the other polishing parameters (e.g., particle size distribution and the properties of the polishing pad). The resulting K concentration depth profiles are described using a two-step diffusion process: (1) steady-state moving boundary diffusion (due to material removal during polishing) followed by (2) simple diffusion during ambient postpolishing storage. Using known alkali metal diffusion coefficients in fused silica glass, this diffusion model predicts concentration profiles that are consistent with the measured data at various polishing material removal rates. On the other hand, the observed Ce profiles are inconsistent with diffusion based transport. Rather we propose that Ce penetration is governed by the ratio of Ce–O–Si and Si–O–Si hydrolysis rates; where this ratio increases with interface temperature (which increases with polishing material removal rate) resulting in greater Ce penetration into the Beilby layer. Calculated Ce surface concentrations using this mechanism are in good agreement to the observed change in measured Ce surface concentrations with polishing material removal rate. In conclusion, these new insights into the chemistry of the Beilby layer, combined together with details of the single particle removal function during polishing, are used to develop a more detailed and quantitative picture of the polishing process and the formation of the Beilby layer.« less

Effective characterization of polymer residues on two-dimensional materials by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Park, Ji-Hoon; Choi, Soo Ho; Chae, Won Uk; Stephen, Boandoh; Park, Hyeon Ki; Yang, Woochul; Kim, Soo Min; Lee, Joo Song; Kim, Ki Kang

2015-12-01

Large-area two-dimensional (2D) materials grown by chemical vapor deposition need to be transferred onto a target substrate for real applications. Poly(methyl methacrylate) as a supporting layer is widely used during the transfer process and removed after finishing it. However, it is a challenge to diminish the polymer layer completely. It is necessary to readily characterize the polymer residues on 2D materials to facilitate the removal process. Here, we report a method that characterizes the polymer residues on 2D materials by tracking the presence of G-band of amorphous carbons (a-Cs) in the Raman spectrum after forming carbonized a-Cs through thermal annealing. The 13C-graphene is employed to separate the Raman signal G-band between 12C-a-Cs and 13C-graphene in the Raman spectrum. The residence of the polymer residues is clearly confirmed by the different Raman signals of two different isotopes (12C and 13C) due to differences in mass. Our effective method recognizes that while the polymer residue is not easily removed on graphene, those on hexagonal boron nitride and molybdenum disulfide are almost diminished under optimum thermal annealing conditions. Our method will not only contribute to the development of a new transfer process, but also help to achieve a clean surface of 2D materials.

Reductions of dissolved organic matter and disinfection by-product precursors in full-scale wastewater treatment plants in winter.

PubMed

Xue, Shuang; Jin, Wujisiguleng; Zhang, Zhaohong; Liu, Hong

2017-07-01

The reductions of dissolved organic matter (DOM) and disinfection byproduct precursors in four full-scale wastewater treatment plants (WWTPs) (Liaoning Province, China) where different biological treatment processes were employed in winter were investigated. The total removal efficiencies of dissolved organic carbon (DOC), ultraviolet light at 254 nm (UV-254), trihalomethane formation potential (THMFP), and haloacetic acid formation potential (HAAFP) were in the range of 70.3-76.0%, 49.6-57.3%, 54.4-65.0%, and 53.7-63.8% in the four WWTPs, respectively. The biological treatment was the predominant process responsible for the removal of DOC, THMFP, and HAAFP in WWTPs. Differences in the reduction of UV-254 were not significant (p > 0.05) among biochemical reaction pool, secondary sedimentation tank, and disinfection tank. Biological aerated filter and suspended carrier activated sludge processes achieved higher DOM removal than the conventional active sludge and anaerobic-anoxic-oxic processes. Hydrophobic neutral and hydrophilic fraction were removed to a higher degree through biological treatment than the other three DOM fractions. HAAFP removal was more efficient than THMFP reduction during biological treatment. During primary treatment, fluorescent materials in secondary sedimentation tanks were preferentially removed, as compared to the bulk DOM. Humic-like fluorescent compounds were not readily eliminated during biological treatment. The fluorescent materials were more susceptible to chlorine than nonfluorescent compounds. Copyright © 2017. Published by Elsevier Ltd.

Kinematical and mechanical aspects of wafer slicing

NASA Technical Reports Server (NTRS)

Werner, P. G.

1982-01-01

Some recently achieved results concerning the technological fundamentals of slurry sawing are presented. The specific material removal process and the related kinematic and geometric contact conditions between workpiece and saw blade are described. The result of a functional description of the slurry sawing process is presented, expressing the main process criteria, such as infeed per stroke, specific removal rate, specific tool wear, and vertical stroke intensity, in terms of the dominating process parameters, such as stroke length, width of workpiece, stroke frequency, specific cutting force and slurry specification.

Chemistry and microbiology of permeable reactive barriers for in situ groundwater clean up.

PubMed

Scherer, M M; Richter, S; Valentine, R L; Alvarez, P J

2000-01-01

Permeable reactive barriers (PRBs) are receiving a great deal of attention as an innovative, cost-effective technology for in situ clean up of groundwater contamination. A wide variety of materials are being proposed for use in PRBs, including zero-valent metals (e.g., iron metal), humic materials, oxides, surfactant-modified zeolites (SMZs), and oxygen- and nitrate-releasing compounds. PRB materials remove dissolved groundwater contaminants by immobilization within the barrier or transformation to less harmful products. The primary removal processes include: (1) sorption and precipitation, (2) chemical reaction, and (3) biologically mediated reactions. This article presents an overview of the mechanisms and factors controlling these individual processes and discusses the implications for the feasibility and long-term effectiveness of PRB technologies.

Evaluation of layered zinc hydroxide nitrate and zinc/nickel double hydroxide salts in the removal of chromate ions from solutions

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

Bortolaz de Oliveira, Henrique; Wypych, Fernando, E-mail: wypych@ufpr.br

Layered zinc hydroxide nitrate (ZnHN) and Zn/Ni layered double hydroxide salts were synthesized and used to remove chromate ions from solutions at pH 8.0. The materials were characterized by many instrumental techniques before and after chromate ion removal. ZnHN decomposed after contact with the chromate solution, whereas the layered structure of Zn/Ni hydroxide nitrate (Zn/NiHN) and Zn/Ni hydroxide acetate (Zn/NiHA) remained their layers intact after the topotactic anionic exchange reaction, only changing the basal distances. ZnHN, Zn/NiHN, and Zn/NiHA removed 210.1, 144.8, and 170.1 mg of CrO{sub 4}{sup 2−}/g of material, respectively. Although the removal values obtained for Zn/NiHN andmore » Zn/NiHA were smaller than the values predicted for the ideal formulas of the solids (194.3 and 192.4 mg of CrO{sub 4}{sup 2−}/g of material, respectively), the measured capacities were higher than the values achieved with many materials reported in the literature. Kinetic experiments showed the removal reaction was fast. To facilitate the solid/liquid separation process after chromium removal, Zn/Ni layered double hydroxide salts with magnetic supports were also synthesized, and their ability to remove chromate was evaluated. - Highlights: • Zinc hydroxide nitrate and Zn/Ni hydroxide nitrate or acetate were synthesized. • The interlayer anions were replaced by chromate anions at pH=8.0. • Only Zn/Ni hydroxide nitrate or acetate have the structure preserved after exchange. • Fast exchange reaction and high capacity of chromate removal were observed. • Magnetic materials were obtained to facilitate the solids removal the from solutions.« less

Lowering the environmental impact of high-kappa/ metal gate stack surface preparation processes

NASA Astrophysics Data System (ADS)

Zamani, Davoud

ABSTRACT Hafnium based oxides and silicates are promising high-κ dielectrics to replace SiO2 as gate material for state-of-the-art semiconductor devices. However, integrating these new high-κ materials into the existing complementary metal-oxide semiconductor (CMOS) process remains a challenge. One particular area of concern is the use of large amounts of HF during wet etching of hafnium based oxides and silicates. The patterning of thin films of these materials is accomplished by wet etching in HF solutions. The use of HF allows dissolution of hafnium as an anionic fluoride complex. Etch selectivity with respect to SiO2 is achieved by appropriately diluting the solutions and using slightly elevated temperatures. From an ESH point of view, it would be beneficial to develop methods which would lower the use of HF. The first objective of this study is to find new chemistries and developments of new wet etch methods to reduce fluoride consumption during wet etching of hafnium based high-κ materials. Another related issue with major environmental impact is the usage of large amounts of rinsing water for removal of HF in post-etch cleaning step. Both of these require a better understanding of the HF interaction with the high-κ surface during the etching, cleaning, and rinsing processes. During the rinse, the cleaning chemical is removed from the wafers. Ensuring optimal resource usage and cycle time during the rinse requires a sound understanding and quantitative description of the transport effects that dominate the removal rate of the cleaning chemicals from the surfaces. Multiple processes, such as desorption and re-adsorption, diffusion, migration and convection, all factor into the removal rate of the cleaning chemical during the rinse. Any of these processes can be the removal rate limiting process, the bottleneck of the rinse. In fact, the process limiting the removal rate generally changes as the rinse progresses, offering the opportunity to save resources. The second objective of this study is to develop new rinse methods to reduce water and energy usage during rinsing and cleaning of hafnium based high-κ materials in single wafer-cleaning tools. It is necessary to have a metrology method which can study the effect of all process parameters that affect the rinsing by knowing surface concentration of contaminants in patterned hafnium based oxides and silicate wafers. This has been achieved by the introduction of a metrology method at The University of Arizona which monitors the transport of contaminant concentrations inside micro- and nano- structures. This is the only metrology which will be able to provide surface concentration of contaminants inside hafnium based oxides and silicate micro-structures while the rinsing process is taking place. The goal of this research is to study the effect of various process parameters on rinsing of patterned hafnium based oxides and silicate wafers, and modify a metrology method for end point detection.

Removal of ion-implanted photoresists on GaAs using two organic solvents in sequence

NASA Astrophysics Data System (ADS)

Oh, Eunseok; Na, Jihoon; Lee, Seunghyo; Lim, Sangwoo

2016-07-01

Organic solvents can effectively remove photoresists on III-V channels without damage or etching of the channel material during the process. In this study, a two-step sequential photoresist removal process using two different organic solvents was developed to remove implanted ArF and KrF photoresists at room temperature. The effects of organic solvents with either low molar volumes or high affinities for photoresists were evaluated to find a proper combination that can effectively remove high-dose implanted photoresists without damaging GaAs surfaces. The performance of formamide, acetonitrile, nitromethane, and monoethanolamine for the removal of ion-implanted ArF and KrF photoresists were compared using a two-step sequential photoresist removal process followed by treatment in dimethyl sulfoxide (DMSO). Among the various combinations, the acetonitrile + DMSO two-step sequence exhibited the best removal of photoresists that underwent ion implantation at doses of 5 × 1013-5 × 1015 atoms/cm2 on both flat and trench-structured GaAs surfaces. The ability of the two-step process using organic solvents to remove the photoresists can be explained by considering the affinities of solvents for a polymer and its permeability through the photoresist.

[The remove characteristics of dissolved organic matter in landfill leachate during the treatment process].

PubMed

He, Xiao-Song; Yu, Jing; Xi, Bei-Dou; Jiang, Yong-Hai; Zhang, Jin-Bao; Li, Dan; Pan, Hong-Wei; Liu, Hong-Liang

2012-09-01

In order to investigate remove characteristics of dissolved organic matter in landfill leachate, leachates were sampled during the process (i. e. , adjusting tank, anaerobic zone, oxidation ditch and MBR processing). Dissolved organic matter was extracted and its content and structure were characterized by fluorescence excitation-emission matrix spectra, UV-Vis specrtra and FTIR spectra. The results showed that an amount of 377.6 mg x L(-1) dissolved organic carbon (DOC) was removed during the whole treatment process, and the total removal rate was up to 78.34%. The 25.56% of DOC in the adjusting tank was removed during the anaerobic zone, 41.58% of DOC in anaerobic effluent was removed during the oxidation ditch, while 50.19% of DOC in the oxidation ditch effluent decreased in the MBR process. The anaerobic process increased the content of unsaturated compound and polysaccharides in leachate DOM, which improved the leachate biochemical characteristics. The unsaturated compound and polysaccharides were removed effectively during being in oxidation ditch. Protein-like and humic-like fluorescence peaks were observed in the adjusting tank and anaerobic zone, while humic-like fluorescence peaks were just presented in the oxidation ditch and MBR processing. Protein-like and fulvic-like substances were biodegraded in the adjusting tank and anaerobic zone, while humic-like materials were removed in the MBR process.

Sulfur‐Limonene Polysulfide: A Material Synthesized Entirely from Industrial By‐Products and Its Use in Removing Toxic Metals from Water and Soil

PubMed Central

Crockett, Michael P.; Evans, Austin M.; Worthington, Max J. H.; Albuquerque, Inês S.; Slattery, Ashley D.; Gibson, Christopher T.; Campbell, Jonathan A.; Lewis, David A.; Bernardes, Gonçalo J. L.

2015-01-01

Abstract A polysulfide material was synthesized by the direct reaction of sulfur and d‐limonene, by‐products of the petroleum and citrus industries, respectively. The resulting material was processed into functional coatings or molded into solid devices for the removal of palladium and mercury salts from water and soil. The binding of mercury(II) to the sulfur‐limonene polysulfide resulted in a color change. These properties motivate application in next‐generation environmental remediation and mercury sensing. PMID:26481099

Calcination does not remove all carbon from colloidal nanocrystal assemblies

DOE PAGES

Mohapatra, Pratyasha; Shaw, Santosh; Mendivelso-Perez, Deyny; ...

2017-12-11

Removing organics from hybrid nanostructures is a crucial step in many bottom-up materials fabrication approaches. It is usually assumed that calcination is an effective solution to this problem, especially for thin films. This assumption has led to its application in thousands of papers. Here in this paper, we show that this general assumption is incorrect by using a relevant and highly controlled model system consisting of thin films of ligand-capped ZrO 2 nanocrystals. After calcination at 800 °C for 12 h, while Raman spectroscopy fails to detect the ligands after calcination, elastic backscattering spectrometry characterization demonstrates that ~18% of themore » original carbon atoms are still present in the film. By comparison plasma processing successfully removes the ligands. Our growth kinetic analysis shows that the calcined materials have significantly different interfacial properties than the plasma-processed counterparts. Calcination is not a reliable strategy for the production of single-phase all-inorganic materials from colloidal nanoparticles.« less

Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media.

PubMed

Lacasa, Engracia; Cañizares, Pablo; Llanos, Javier; Rodrigo, Manuel A

2012-04-30

In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO, N(2)O and NO(2)) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities. Copyright © 2012 Elsevier B.V. All rights reserved.

Optimization and Analysis of Laser Beam Machining Parameters for Al7075-TiB2 In-situ Composite

NASA Astrophysics Data System (ADS)

Manjoth, S.; Keshavamurthy, R.; Pradeep Kumar, G. S.

2016-09-01

The paper focuses on laser beam machining (LBM) of In-situ synthesized Al7075-TiB2 metal matrix composite. Optimization and influence of laser machining process parameters on surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy of composites were studied. Al7075-TiB2 metal matrix composite was synthesized by in-situ reaction technique using stir casting process. Taguchi's L9 orthogonal array was used to design experimental trials. Standoff distance (SOD) (0.3 - 0.5mm), Cutting Speed (1000 - 1200 m/hr) and Gas pressure (0.5 - 0.7 bar) were considered as variable input parameters at three different levels, while power and nozzle diameter were maintained constant with air as assisting gas. Optimized process parameters for surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy were calculated by generating the main effects plot for signal noise ratio (S/N ratio) for surface roughness, VMRR and dimensional error using Minitab software (version 16). The Significant of standoff distance (SOD), cutting speed and gas pressure on surface roughness, volumetric material removal rate (VMRR) and dimensional error were calculated using analysis of variance (ANOVA) method. Results indicate that, for surface roughness, cutting speed (56.38%) is most significant parameter followed by standoff distance (41.03%) and gas pressure (2.6%). For volumetric material removal (VMRR), gas pressure (42.32%) is most significant parameter followed by cutting speed (33.60%) and standoff distance (24.06%). For dimensional error, Standoff distance (53.34%) is most significant parameter followed by cutting speed (34.12%) and gas pressure (12.53%). Further, verification experiments were carried out to confirm performance of optimized process parameters.

Dynamic study of Cr(VI) removal performance and mechanism from water using multilayer material coated nanoscale zerovalent iron.

PubMed

Wu, Bin; Peng, Dinghua; Hou, Siyu; Tang, Bicong; Wang, Can; Xu, Heng

2018-05-16

In this study, the dynamic Cr(VI) removal process from water by the synthesized multilayer material coated nanoscale zerovalent iron (SBC-nZVI) was systematically discussed at different treatment conditions. The results showed that initial pH, contact time, Cr(VI) concentration and the dosage of SBC-nZVI were important parameters that influenced the Cr(VI) removal efficiency. The major Cr(VI) removal occurred within 60 min and gradually tend to equilibrium with consistent treatment. The removal efficiency was highly depended on pH values and the adsorption kinetics agreed well with the pseduo-second-order model (PSO). When the initial Cr(VI) concentration was below 15 mg/L, the removal rate could reach to about 100%. Moreover, the removal efficiency increased with the increase of SBC-nZVI dosage, which related to the increase of reactive sites. To understand the removal mechanism, SBC-nZVI before and after reaction with Cr(VI) were characterized by fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). These analysis showed that the interaction of SBC-nZVI with Cr(VI) was mainly controlled by reduction and electrostatic attraction. Therefore, these results explained the interaction between Cr(VI) and SBC-nZVI material in detail, and further proved that SBC-nZVI could be an effective material to remove Cr(VI) from water. Copyright © 2018. Published by Elsevier Ltd.

Information Security Program Regulation

DTIC Science & Technology

1986-06-01

above. When an alarmed area is used for the storage of Top Secret material, the physical barrier must be adequate to prevent (a) surreptitious removal ...IV-9 4-304 Removable ADP and Word Processing Storage Media ---------- IV-10 4-305 Documents Produced by ADP Equipment...with a removal or cancellation of the classification designation. 1-315 Declassification Event An event that eliminates the need for continued

Positive dwell time algorithm with minimum equal extra material removal in deterministic optical surfacing technology.

PubMed

Li, Longxiang; Xue, Donglin; Deng, Weijie; Wang, Xu; Bai, Yang; Zhang, Feng; Zhang, Xuejun

2017-11-10

In deterministic computer-controlled optical surfacing, accurate dwell time execution by computer numeric control machines is crucial in guaranteeing a high-convergence ratio for the optical surface error. It is necessary to consider the machine dynamics limitations in the numerical dwell time algorithms. In this paper, these constraints on dwell time distribution are analyzed, and a model of the equal extra material removal is established. A positive dwell time algorithm with minimum equal extra material removal is developed. Results of simulations based on deterministic magnetorheological finishing demonstrate the necessity of considering machine dynamics performance and illustrate the validity of the proposed algorithm. Indeed, the algorithm effectively facilitates the determinacy of sub-aperture optical surfacing processes.

Surface and subsurface cracks characteristics of single crystal SiC wafer in surface machining

NASA Astrophysics Data System (ADS)

Qiusheng, Y.; Senkai, C.; Jisheng, P.

2015-03-01

Different machining processes were used in the single crystal SiC wafer machining. SEM was used to observe the surface morphology and a cross-sectional cleavages microscopy method was used for subsurface cracks detection. Surface and subsurface cracks characteristics of single crystal SiC wafer in abrasive machining were analysed. The results show that the surface and subsurface cracks system of single crystal SiC wafer in abrasive machining including radial crack, lateral crack and the median crack. In lapping process, material removal is dominated by brittle removal. Lots of chipping pits were found on the lapping surface. With the particle size becomes smaller, the surface roughness and subsurface crack depth decreases. When the particle size was changed to 1.5µm, the surface roughness Ra was reduced to 24.0nm and the maximum subsurface crack was 1.2µm. The efficiency of grinding is higher than lapping. Plastic removal can be achieved by changing the process parameters. Material removal was mostly in brittle fracture when grinding with 325# diamond wheel. Plow scratches and chipping pits were found on the ground surface. The surface roughness Ra was 17.7nm and maximum subsurface crack depth was 5.8 µm. When grinding with 8000# diamond wheel, the material removal was in plastic flow. Plastic scratches were found on the surface. A smooth surface of roughness Ra 2.5nm without any subsurface cracks was obtained. Atomic scale removal was possible in cluster magnetorheological finishing with diamond abrasive size of 0.5 µm. A super smooth surface eventually obtained with a roughness of Ra 0.4nm without any subsurface crack.

Removal of Cu(II) and Pb(II) from Aqueous Solutions Using Nanoporous Materials

NASA Astrophysics Data System (ADS)

Dutta, Debajani; Roy, Sushanta Kumar; Das, Bodhaditya; Talukdar, Anup K.

2018-05-01

The present work deals with the adsorption of Cu2+ and Pb2+ on zeolites (ZSM-5, mordenite) and mesoporous materials (MCM-48, MCM-41). The characterization of the synthesized samples was performed by means of XRD, SEM, and thermogravimetric analysis. The batch method was employed to study the influence of adsorbent nature, contact time, initial metal ion concentration, and adsorbent load. The adsorption on MCM-48 follows a pseudo-second-order kinetic model. This material was found to be more effective for the removal of lead in a batch process as compared to the other adsorbents and the removal efficiency of the materials for Pb(II) followed the order MCM-48 > mordenite > ZSM-5 > MCM-41 and that for Cu(II) followed the order ZSM-5 > mordenite > MCM-41 > MCM-48.

Thermal stir welding process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey (Inventor)

2012-01-01

A welding method is provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

Application of low temperature plasmas for restoration/conservation of archaeological objects

NASA Astrophysics Data System (ADS)

Krčma, F.; Blahová, L.; Fojtíková, P.; Graham, W. G.; Grossmannová, H.; Hlochová, L.; Horák, J.; Janová, D.; Kelsey, C. P.; Kozáková, Z.; Mazánková, V.; Procházka, M.; Přikryl, R.; Řádková, L.; Sázavská, V.; Vašíček, M.; Veverková, R.; Zmrzlý, M.

2014-12-01

The low-temperature low-pressure hydrogen based plasmas were used to study the influence of processes and discharge conditions on corrosion removal. The capacitive coupled RF discharge in the continuous or pulsed regime was used at operating pressure of 100-200 Pa. Plasma treatment was monitored by optical emission spectroscopy. To be able to study influence of various process parameters, the model corroded samples with and without sandy incrustation were prepared. The SEM-EDX analyzes were carried out to verify corrosion removal efficiency. Experimental conditions were optimized for the selected most frequent materials of original metallic archaeological objects (iron, bronze, copper, and brass). Chlorides removal is based on hydrogen ion reactions while oxides are removed mainly by neutral species interactions. A special focus was kept for the samples temperature because it was necessary to avoid any metallographic changes in the material structure. The application of higher power pulsed regime with low duty cycle seems be the best treatment regime. The low pressure hydrogen plasma is not applicable for objects with a very broken structure or for nonmetallic objects due to the non-uniform heat stress. Due to this fact, the new developed plasmas generated in liquids were applied on selected original archaeological glass materials.

Mechanical Serial-Sectioning Data Assistant

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

Poulter, Gregory A.; Madison, Jonathan D.

Mechanical Serial-Sectioning Data Assistant (MECH-SSDA) is a real-time data analytics software with graphical user-interface that; 1) tracks and visualizes material removal rates for mechanical serial-sectioning experiments using at least two height measurement methods; 2) tracks process time for specific segments of the serial-sectioning experiment; and 3) alerts the user to anomalies in expected removal rate, process time or unanticipated operational pauses

PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

DOEpatents

Overholt, D.C.; Peterson, M.D.; Acken, M.F.

1958-09-16

A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

Process to recycle shredder residue

DOEpatents

Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.

2001-01-01

A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

Electronic-carrier-controlled photochemical etching process in semiconductor device fabrication

DOEpatents

Ashby, C.I.H.; Myers, D.R.; Vook, F.L.

1988-06-16

An electronic-carrier-controlled photochemical etching process for carrying out patterning and selective removing of material in semiconductor device fabrication includes the steps of selective ion implanting, photochemical dry etching, and thermal annealing, in that order. In the selective ion implanting step, regions of the semiconductor material in a desired pattern are damaged and the remainder of the regions of the material not implanted are left undamaged. The rate of recombination of electrons and holes is increased in the damaged regions of the pattern compared to undamaged regions. In the photochemical dry etching step which follows ion implanting step, the material in the undamaged regions of the semiconductor are removed substantially faster than in the damaged regions representing the pattern, leaving the ion-implanted, damaged regions as raised surface structures on the semiconductor material. After completion of photochemical dry etching step, the thermal annealing step is used to restore the electrical conductivity of the damaged regions of the semiconductor material.

Electronic-carrier-controlled photochemical etching process in semiconductor device fabrication

DOEpatents

Ashby, Carol I. H.; Myers, David R.; Vook, Frederick L.

1989-01-01

An electronic-carrier-controlled photochemical etching process for carrying out patterning and selective removing of material in semiconductor device fabrication includes the steps of selective ion implanting, photochemical dry etching, and thermal annealing, in that order. In the selective ion implanting step, regions of the semiconductor material in a desired pattern are damaged and the remainder of the regions of the material not implanted are left undamaged. The rate of recombination of electrons and holes is increased in the damaged regions of the pattern compared to undamaged regions. In the photochemical dry etching step which follows ion implanting step, the material in the undamaged regions of the semiconductor are removed substantially faster than in the damaged regions representing the pattern, leaving the ion-implanted, damaged regions as raised surface structures on the semiconductor material. After completion of photochemical dry etching step, the thermal annealing step is used to restore the electrical conductivity of the damaged regions of the semiconductor material.

Extraction of metals and/or metalloids from acidic media using supercritical fluids and salts

DOEpatents

Wai, C.M.; Smart, N.G.; Lin, Y.

1998-06-23

A method is described for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical carbon dioxide, containing a chelating agent. The chelating agent forms chelates that are soluble in the fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent comprises a trialkyl phosphate, a triaryl phosphate, a trialkylphosphine oxide, a triarylphosphine oxide, or mixtures thereof. The method provides an environmentally benign process for removing contaminants from industrial waste. The method is particularly useful for extracting actinides from acidic solutions, and the process can be aided by the addition of nitrate salts. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process. 7 figs.

Heavy metal removal capacity of individual components of permeable reactive concrete

NASA Astrophysics Data System (ADS)

Holmes, Ryan R.; Hart, Megan L.; Kevern, John T.

2017-01-01

Permeable reactive barriers (PRBs) are a well-known technique for groundwater remediation using industrialized reactive media such as zero-valent iron and activated carbon. Permeable reactive concrete (PRC) is an alternative reactive medium composed of relatively inexpensive materials such as cement and aggregate. A variety of multimodal, simultaneous processes drive remediation of metals from contaminated groundwater within PRC systems due to the complex heterogeneous matrix formed during cement hydration. This research investigated the influence coarse aggregate, portland cement, fly ash, and various combinations had on the removal of lead, cadmium, and zinc in solution. Absorption, adsorption, precipitation, co-precipitation, and internal diffusion of the metals are common mechanisms of removal in the hydrated cement matrix and independent of the aggregate. Local aggregates can be used as the permeable structure also possessing high metal removal capabilities, however calcareous sources of aggregate are preferred due to improved removal with low leachability. Individual adsorption isotherms were linear or curvilinear up, indicating a preferred removal process. For PRC samples, metal saturation was not reached over the range of concentrations tested. Results were then used to compare removal against activated carbon and aggregate-based PRBs by estimating material costs for the remediation of an example heavy metal contaminated Superfund site located in the Midwestern United States, Joplin, Missouri.

Chitin/clay microspheres with hierarchical architecture for highly efficient removal of organic dyes.

PubMed

Xu, Rui; Mao, Jie; Peng, Na; Luo, Xiaogang; Chang, Chunyu

2018-05-15

Numerous adsorbents have been reported for efficient removal of dye from water, but the high cost raw materials and complicated fabrication process limit their practical applications. Herein, novel nanocomposite microspheres were fabricated from chitin and clay by a simple thermally induced sol-gel transition. Clay nanosheets were uniformly embedded in a nanofiber weaved chitin microsphere matrix, leading to their hierarchical architecture. Benefiting from this unique structure, microspheres could efficiently remove methylene blue (MB) through a spontaneous physic-sorption process which fit well with pseudo-second-order and Langmuir isotherm models. The maximal values of adsorption capability obtained by calculation and experiment were 152.2 and 156.7 mg g -1 , respectively. Chitin/clay microspheres (CCM2) could remove 99.99% MB from its aqueous solution (10 mg g -1 ) within 20 min. These findings provide insight into a new strategy for fabrication of dye adsorbents with hierarchical structure from low cost raw materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Toward Magnetorheological Finishing of Magnetic Materials

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

Shafrir, S.N.; Lambropoulos, J.C.; Jacobs, S.D.

2007-10-24

Magnetorheological finishing (MRF) is a precision finishing process traditionally limited to processing only nonmagnetic materials, e.g., optical glasses, ceramics, polymers, and metals. Here we demonstrate that MRF can be used for material removal from magnetic material surfaces. Our approach is to place an MRF spot on machined surfaces of magnetic WC-Co materials. The resulting surface roughness is comparable to that produced on nonmagnetic materials. This spotting technique may be used to evaluate the depth of subsurface damage, or deformed layer, induced by earlier manufacturing steps, such as grinding and lapping.

Vacuum Baking To Remove Volatile Materials

NASA Technical Reports Server (NTRS)

Muscari, J. A.

1985-01-01

Outgassing reduced in some but not all nonmetallic materials. Eleven polymeric materials tested by determining outgassing species as temperature of conditioned and unconditioned materials raised to 300 degrees C. Conditioning process consisted of vacuum bake for 24 hours at 80 degrees C in addition to usual cure. Baking did not change residual gas percentage of water molecules.

Process simulation and cost analysis for removing inorganics from wood chips using combined mechanical and chemical preprocessing

DOE PAGES

Hu, Hongqiang; Westover, Tyler L.; Cherry, Robert; ...

2016-10-03

Inorganic species (ash) in biomass feedstocks negatively impact thermochemical and biochemical energy conversion processes. In this work, a process simulation model is developed to model the reduction in ash content of loblolly logging residues using a combination of air classification and dilute-acid leaching. Various scenarios are considered, and it is found that costs associated with discarding high-ash material from air classification are substantial. The costs of material loss can be reduced by chemical leaching the high-ash fraction obtained from air classification. The optimal leaching condition is found to be approximately 0.1 wt% sulfuric acid at 24°C. In example scenarios, totalmore » process costs in the range of $10-12/dry tonnes of product are projected that result in a removal of 11, 66, 53 and 86% of organics, total ash (inorganics), alkaline earth metals and phosphorus (AAEMS+P), and silicon, respectively. Here, sensitivity analyses indicate that costs associated with loss of organic material during processing (yield losses), brine disposal, and labor have the greatest potential to impact the total processing cost.« less

Could microwave induced catalytic oxidation (MICO) process over CoFe2O4 effectively eliminate brilliant green in aqueous solution?

PubMed

Ju, Yongming; Wang, Xiaoyan; Qiao, Junqin; Li, Guohua; Wu, You; Li, Yuan; Zhang, Xiuyu; Xu, Zhencheng; Qi, Jianying; Fang, Jiande; Dionysiou, Dionysios D

2013-12-15

In this study, we adopted the chemical co-precipitation (CP) method and sol-gel method followed by calcination at temperatures of 100-900°C for 12h to synthesize CoFe2O4 materials, which were further characterized by TEM, XRD and XPS techniques. The properties of CoFe2O4 materials were evaluated in a microwave (MW) induced catalytic oxidation (MICO) process for the elimination of brilliant green (BG). The results showed that: (1) the removal rates of BG gradually decreased over a series of CoFe2O4 materials prepared by CP method and calcinated with 100-700°C (except 900°C) for 12h within three reuse cycles; for comparison, no removal of BG was obtained over CoFe2O4 synthesized by sol-gel method and CoFe2O4-900 (CP); (2) no hydroxyl radicals were captured with salicylic acid used as molecular probe in the MICO process; (3) MW irradiation enhanced the release of residual NaOH within the microstructure of CoFe2O4 and further discolored BG, because BG is sensitive to pH; (4) granular activated carbon (GAC), an excellent MW-absorbing material possessing higher dielectric loss tangent compared to that of a series of CoFe2O4 materials, could not remove BG in suspensions at a higher efficiency, even if the loading amount was 20 g L(-1). Accordingly, MICO process over CoFe2O4 materials and GAC could not effectively eliminate BG in suspensions. Copyright © 2013 Elsevier B.V. All rights reserved.

Standard Isotherm Fit Information for Dry CO2 on Sorbents for 4-Bed Molecular Sieve

NASA Technical Reports Server (NTRS)

Cmarik, G. E.; Son, K. N.; Knox, J. C.

2017-01-01

Onboard the ISS, one of the systems tasked with removal of metabolic carbon dioxide (CO2) is a 4-bed molecular sieve (4BMS) system. In order to enable a 4-person mission to succeed, systems for removal of metabolic CO2 must reliably operate for several years while minimizing power, mass, and volume requirements. This minimization can be achieved through system redesign and/or changes to the separation material(s). A material screening process has identified the most reliable sorbent materials for the next 4BMS. Sorbent characterization will provide the information necessary to guide system design by providing inputs for computer simulations.

Electromagnetic mixed waste processing system for asbestos decontamination

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

Kasevich, R.S.; Vaux, W.; Ulerich, N.

The overall objective of this three-phase program is to develop an integrated process for treating asbestos-containing material that is contaminated with radioactive and hazardous constituents. The integrated process will attempt to minimize processing and disposal costs. The objectives of Phase 1 were to establish the technical feasibility of asbestos decomposition, inorganic radionuclide nd heavy metal removal, and organic volatilization. Phase 1 resulted in the successful bench-scale demonstration of the elements required to develop a mixed waste treatment process for asbestos-containing material (ACM) contaminated with radioactive metals, heavy metals, and organics. Using the Phase 1 data, a conceptual process was developed.more » The Phase 2 program, currently in progress, is developing an integrated system design for ACM waste processing. The Phase 3 program will target demonstration of the mixed waste processing system at a DOE facility. The electromagnetic mixed waste processing system employs patented technologies to convert DOE asbestos to a non-hazardous, radionuclide-free, stable waste. The dry, contaminated asbestos is initially heated with radiofrequency energy to remove organic volatiles. Second,the radionuclides are removed by solvent extraction coupled with ion exchange solution treatment. Third, the ABCOV method converts the asbestos to an amorphous silica suspension at low temperature (100{degrees}C). Finally the amorphous silica is solidified for disposal.« less

AFRL Projects to Replace Cadmium

DTIC Science & Technology

2005-03-01

Protocol does not – Identify/ select a material or process – Impose processing restrictions on candidates – Implement a material or process into production...within proper limits • Use XRF to measure composition and thickness – Strippability • Remove coating within 60 minutes • Replate coating and pass...product information available? Magnetron Sputtering to Replace Cd • Task 2: Coating Deposition and Screening – Selection of qualified vendors and

Laser Processing of Multilayered Thermal Spray Coatings: Optimal Processing Parameters

NASA Astrophysics Data System (ADS)

Tewolde, Mahder; Zhang, Tao; Lee, Hwasoo; Sampath, Sanjay; Hwang, David; Longtin, Jon

2017-12-01

Laser processing offers an innovative approach for the fabrication and transformation of a wide range of materials. As a rapid, non-contact, and precision material removal technology, lasers are natural tools to process thermal spray coatings. Recently, a thermoelectric generator (TEG) was fabricated using thermal spray and laser processing. The TEG device represents a multilayer, multimaterial functional thermal spray structure, with laser processing serving an essential role in its fabrication. Several unique challenges are presented when processing such multilayer coatings, and the focus of this work is on the selection of laser processing parameters for optimal feature quality and device performance. A parametric study is carried out using three short-pulse lasers, where laser power, repetition rate and processing speed are varied to determine the laser parameters that result in high-quality features. The resulting laser patterns are characterized using optical and scanning electron microscopy, energy-dispersive x-ray spectroscopy, and electrical isolation tests between patterned regions. The underlying laser interaction and material removal mechanisms that affect the feature quality are discussed. Feature quality was found to improve both by using a multiscanning approach and an optional assist gas of air or nitrogen. Electrically isolated regions were also patterned in a cylindrical test specimen.

Nanocellulose-Based Materials for Water Purification

PubMed Central

Voisin, Hugo; Bergström, Lennart; Liu, Peng; Mathew, Aji P.

2017-01-01

Nanocellulose is a renewable material that combines a high surface area with high strength, chemical inertness, and versatile surface chemistry. In this review, we will briefly describe how nanocellulose is produced, and present—in particular, how nanocellulose and its surface modified versions affects the adsorption behavior of important water pollutants, e.g., heavy metal species, dyes, microbes, and organic molecules. The processing of nanocellulose-based membranes and filters for water purification will be described in detail, and the uptake capacity, selectivity, and removal efficiency will also be discussed. The processing and performance of nanocellulose-based membranes, which combine a high removal efficiency with anti-fouling properties, will be highlighted. PMID:28336891

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, packing material is placed over the nose cap that was removed from Atlantis. The reinforced carbon-carbon (RCC) nose cap is being sent to the original manufacturing company, Vought in Ft. Worth, Texas, a subsidiary of Lockheed Martin, to undergo non-destructive testing such as CAT scan and thermography.

NASA Image and Video Library

2003-10-29

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, packing material is placed over the nose cap that was removed from Atlantis. The reinforced carbon-carbon (RCC) nose cap is being sent to the original manufacturing company, Vought in Ft. Worth, Texas, a subsidiary of Lockheed Martin, to undergo non-destructive testing such as CAT scan and thermography.

Lithographic dry development using optical absorption

DOEpatents

Olynick, Deirdre; Schuck, P. James; Schmidt, Martin

2013-08-20

A novel approach to dry development of exposed photo resist is described in which a photo resist layer is exposed to a visible light source in order to remove the resist in the areas of exposure. The class of compounds used as the resist material, under the influence of the light source, undergoes a chemical/structural change such that the modified material becomes volatile and is thus removed from the resist surface. The exposure process is carried out for a time sufficient to ablate the exposed resist layer down to the layer below. A group of compounds found to be useful in this process includes aromatic calixarenes.

Paint Removal from Composites and Protective Coating Development

DTIC Science & Technology

1991-01-01

bonds between these layers relax, and the removal of the top layer is facilitated. This phenomena is known as fracking . Cold Jet has completed an initial...sublimed carbon dioxide "atmosphere" and the top layer of material, so that fracking occurs. Cold Jet adds that removal tends to occur layer by layer...often removed faster (than thinner coatings) as a result of the fracking mechanism. The paint residue from the stripping process is comprised of varying

Corrosion inhibition for distillation apparatus

DOEpatents

Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.; Schweighardt, Frank K.

1985-01-01

Tower material corrosion in an atmospheric or sub-atmospheric distillation tower in a coal liquefaction process is reduced or eliminated by subjecting chloride-containing tray contents to an appropriate ion-exchange resin to remove chloride from such tray contents materials.

Fungal nanoscale metal carbonates and production of electrochemical materials.

PubMed

Li, Qianwei; Gadd, Geoffrey Michael

2017-09-01

Fungal biomineralization of carbonates results in metal removal from solution or immobilization within a solid matrix. Such a system provides a promising method for removal of toxic or valuable metals from solution, such as Co, Ni, and La, with some carbonates being of nanoscale dimensions. A fungal Mn carbonate biomineralization process can be applied for the synthesis of novel electrochemical materials. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Crack propagation and the material removal mechanism of glass-ceramics by the scratch test.

PubMed

Qiu, Zhongjun; Liu, Congcong; Wang, Haorong; Yang, Xue; Fang, Fengzhou; Tang, Junjie

2016-12-01

To eliminate the negative effects of surface flaws and subsurface damage of glass-ceramics on clinical effectiveness, crack propagation and the material removal mechanism of glass-ceramics were studied by single and double scratch experiments conducted using an ultra-precision machine. A self-manufactured pyramid shaped single-grit tool with a small tip radius was used as the scratch tool. The surface and subsurface crack propagations and interactions, surface morphology and material removal mechanism were investigated. The experimental results showed that the propagation of lateral cracks to the surface and the interaction between the lateral cracks and radial cracks are the two main types of material peeling, and the increase of the scratch depth increases the propagation angle of the radial cracks and the interaction between the cracks. In the case of a double scratch, the propagation of lateral cracks and radial cracks between paired scratches results in material peeling. The interaction between adjacent scratches depends on the scratch depth and separation distance. There is a critical separation distance where the normalized material removal volume reaches its peak. These findings can help reduce surface flaws and subsurface damage induced by the grinding process and improve the clinical effectiveness of glass-ceramics used as biological substitute and repair materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kinetic studies of potassium permanganate adsorption by activated carbon and its ability as ethylene oxidation material

NASA Astrophysics Data System (ADS)

Aprilliani, F.; Warsiki, E.; Iskandar, A.

2018-03-01

Generally, ethylene production in many horticultural products has been seen to be detrimental to the quality during storage and distribution process. For this reason, removing ethylene from storage or distribution atmosphere is needed to maintain the quality. One of the technologies that can be applied is the use of potassium permanganate (KMnO4). KMnO4 is an active compound that can be used as an oxidizing agent on ethylene removal process. KMnO4 is not recommended for direct used application. As the result, additional material is required to impregnate the potassium permanganate. The inert materials used are commercial activated carbon. Activated carbon is chosen because it has high surface area. The purpose of this research is to determine kinetics adsorption and oxidation model of ethylene removal material. The kinetics adsorption was determined using the pseudo-first and second-order kinetic models. The data on adsorption process show that the second-order equation is more suitable to express the adsorption process on this research. The analyzing of the ethylene oxidation capacity increased with time until it reaches an optimal value. The ethylene oxidation rate is able to be estimated by the formula r = 0.1967 [C2H4]0.99 [KMnO4]0.01; MSE = 0.44 %. The actual and estimation data of ethylene oxidation show that the model is fitted to describe the actual ethylene oxidation under same experimental conditions.

Nanomanufacturing of silicon surface with a single atomic layer precision via mechanochemical reactions.

PubMed

Chen, Lei; Wen, Jialin; Zhang, Peng; Yu, Bingjun; Chen, Cheng; Ma, Tianbao; Lu, Xinchun; Kim, Seong H; Qian, Linmao

2018-04-18

Topographic nanomanufacturing with a depth precision down to atomic dimension is of importance for advancement of nanoelectronics with new functionalities. Here we demonstrate a mask-less and chemical-free nanolithography process for regio-specific removal of atomic layers on a single crystalline silicon surface via shear-induced mechanochemical reactions. Since chemical reactions involve only the topmost atomic layer exposed at the interface, the removal of a single atomic layer is possible and the crystalline lattice beneath the processed area remains intact without subsurface structural damages. Molecular dynamics simulations depict the atom-by-atom removal process, where the first atomic layer is removed preferentially through the formation and dissociation of interfacial bridge bonds. Based on the parametric thresholds needed for single atomic layer removal, the critical energy barrier for water-assisted mechanochemical dissociation of Si-Si bonds was determined. The mechanochemical nanolithography method demonstrated here could be extended to nanofabrication of other crystalline materials.

Municipal waste processing apparatus

DOEpatents

Mayberry, John L.

1988-01-01

Municipal waste materials are processed by crushing the materials so that pieces of noncombustible material are smaller than a selected size and pieces of combustible material are larger than the selected size. The crushed materials are placed on a vibrating mesh screen conveyor belt having openings which pass the smaller, noncombustible pieces of material, but do not pass the larger, combustible pieces of material. Pieces of material which become lodged in the openings of the conveyor belt may be removed by cylindrical deraggers or pressurized air. The crushed materials may be fed onto the conveyor belt by a vibrating feed plate which shakes the materials so that they tend to lie flat.

Removal of Hazardous Pollutants from Wastewaters: Applications of TiO 2 -SiO 2 Mixed Oxide Materials

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

Rasalingam, Shivatharsiny; Peng, Rui; Koodali, Ranjit T.

The direct release of untreated wastewaters from various industries and households results in the release of toxic pollutants to the aquatic environment. Advanced oxidation processes (AOP) have gained wide attention owing to the prospect of complete mineralization of nonbiodegradable organic substances to environmentally innocuous products by chemical oxidation. In particular, heterogeneous photocatalysis has been demonstrated to have tremendous promise in water purification and treatment of several pollutant materials that include naturally occurring toxins, pesticides, and other deleterious contaminants. In this work, we have reviewed the different removal techniques that have been employed for water purification. In particular, the application ofmore » TiO 2 -SiO 2 binary mixed oxide materials for wastewater treatment is explained herein, and it is evident from the literature survey that these mixed oxide materials have enhanced abilities to remove a wide variety of pollutants.« less

Removal of Hazardous Pollutants from Wastewaters: Applications of TiO 2 -SiO 2 Mixed Oxide Materials

DOE PAGES

Rasalingam, Shivatharsiny; Peng, Rui; Koodali, Ranjit T.

2014-01-01

The direct release of untreated wastewaters from various industries and households results in the release of toxic pollutants to the aquatic environment. Advanced oxidation processes (AOP) have gained wide attention owing to the prospect of complete mineralization of nonbiodegradable organic substances to environmentally innocuous products by chemical oxidation. In particular, heterogeneous photocatalysis has been demonstrated to have tremendous promise in water purification and treatment of several pollutant materials that include naturally occurring toxins, pesticides, and other deleterious contaminants. In this work, we have reviewed the different removal techniques that have been employed for water purification. In particular, the application ofmore » TiO 2 -SiO 2 binary mixed oxide materials for wastewater treatment is explained herein, and it is evident from the literature survey that these mixed oxide materials have enhanced abilities to remove a wide variety of pollutants.« less

LITERATURE REVIEWS TO SUPPORT ION EXCHANGE TECHNOLOGY SELECTION FOR MODULAR SALT PROCESSING

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

King, W

2007-11-30

This report summarizes the results of literature reviews conducted to support the selection of a cesium removal technology for application in a small column ion exchange (SCIX) unit supported within a high level waste tank. SCIX is being considered as a technology for the treatment of radioactive salt solutions in order to accelerate closure of waste tanks at the Savannah River Site (SRS) as part of the Modular Salt Processing (MSP) technology development program. Two ion exchange materials, spherical Resorcinol-Formaldehyde (RF) and engineered Crystalline Silicotitanate (CST), are being considered for use within the SCIX unit. Both ion exchange materials havemore » been studied extensively and are known to have high affinities for cesium ions in caustic tank waste supernates. RF is an elutable organic resin and CST is a non-elutable inorganic material. Waste treatment processes developed for the two technologies will differ with regard to solutions processed, secondary waste streams generated, optimum column size, and waste throughput. Pertinent references, anticipated processing sequences for utilization in waste treatment, gaps in the available data, and technical comparisons will be provided for the two ion exchange materials to assist in technology selection for SCIX. The engineered, granular form of CST (UOP IE-911) was the baseline ion exchange material used for the initial development and design of the SRS SCIX process (McCabe, 2005). To date, in-tank SCIX has not been implemented for treatment of radioactive waste solutions at SRS. Since initial development and consideration of SCIX for SRS waste treatment an alternative technology has been developed as part of the River Protection Project Waste Treatment Plant (RPP-WTP) Research and Technology program (Thorson, 2006). Spherical RF resin is the baseline media for cesium removal in the RPP-WTP, which was designed for the treatment of radioactive waste supernates and is currently under construction in Hanford, WA. Application of RF for cesium removal in the Hanford WTP does not involve in-riser columns but does utilize the resin in large scale column configurations in a waste treatment facility. The basic conceptual design for SCIX involves the dissolution of saltcake in SRS Tanks 1-3 to give approximately 6 M sodium solutions and the treatment of these solutions for cesium removal using one or two columns supported within a high level waste tank. Prior to ion exchange treatment, the solutions will be filtered for removal of entrained solids. In addition to Tanks 1-3, solutions in two other tanks (37 and 41) will require treatment for cesium removal in the SCIX unit. The previous SCIX design (McCabe, 2005) utilized CST for cesium removal with downflow supernate processing and included a CST grinder following cesium loading. Grinding of CST was necessary to make the cesium-loaded material suitable for vitrification in the SRS Defense Waste Processing Facility (DWPF). Because RF resin is elutable (and reusable) and processing requires conversion between sodium and hydrogen forms using caustic and acidic solutions more liquid processing steps are involved. The WTP baseline process involves a series of caustic and acidic solutions (downflow processing) with water washes between pH transitions across neutral. In addition, due to resin swelling during conversion from hydrogen to sodium form an upflow caustic regeneration step is required. Presumably, one of these basic processes (or some variation) will be utilized for MSP for the appropriate ion exchange technology selected. CST processing involves two primary waste products: loaded CST and decontaminated salt solution (DSS). RF processing involves three primary waste products: spent RF resin, DSS, and acidic cesium eluate, although the resin is reusable and typically does not require replacement until completion of multiple treatment cycles. CST processing requires grinding of the ion exchange media, handling of solids with high cesium loading, and handling of liquid wash and conditioning solutions. RF processing requires handling and evaporation of cesium eluates, disposal of spent organic resin, and handling of the various liquid wash and regenerate solutions used. In both cases, the DSS will be immobilized in a low activity waste form. It appears that both technologies are mature, well studied, and generally suitable for this application. Technology selection will likely be based on downstream impacts or preferences between the various processing options for the two materials rather than on some unacceptable performance property identified for one material. As a result, the following detailed technical review and summary of the two technologies should be useful to assist in technology selection for SCIX.« less

Comparison of seven kinds of drinking water treatment processes to enhance organic material removal: a pilot test.

PubMed

Chen, Chao; Zhang, Xiaojian; He, Wenjie; Lu, Wei; Han, Hongda

2007-08-15

Organic matter in source water has presented many challenges in the field of water purification, especially for conventional treatment. A two-year-long pilot test comparing water treatment processes was conducted to enhance organic matter removal. The tested process combinations included the conventional process, conventional plus advanced treatment, pre-oxidation plus conventional process and pre-oxidation plus conventional plus advanced treatment. The efficiency of each kind of process was assayed with the comprehensive indices of COD(Mn), TOC, UV(254), AOC, BDOC, THMs, and HAAs and their formation potential. The results showed that the combination of the conventional process and O(3)-BAC provides integrated removal of organic matter and meets the required standards. It is the best performing treatment tested in this investigation for treating polluted source water in China. Moreover, much attention should be paid to organic removal before disinfection to control DBP formation and preserve biostability. This paper also reports the range of efficiency of each unit process to calculate the total efficiency of different process combinations in order to help choose the appropriate water treatment process.

SEMICONDUCTOR TECHNOLOGY Effects of the reciprocating parameters of the carrier on material removal rate and non-uniformity in CMP

NASA Astrophysics Data System (ADS)

Cailing, Wang; Renke, Kang; Zhuji, Jin; Dongming, Guo

2010-12-01

Based on the Preston equation, the mathematical model of the material removal rate (MRR), aiming at a line-orbit chemical mechanical polisher, is established. The MRR and the material removal non-uniformity (MRNU) are numerically calculated by MATLAB, and the effects of the reciprocating parameters on the MRR and the MRNU are discussed. It is shown that the smaller the inclination angle and the larger the amplitude, the higher the MRR and the lower the MRNU. The reciprocating speed of the carrier plays a minor role to improve the MRR and decrease the MRNU. The results provide a guide for the design of a polisher and the determination of a process in line-orbit chemical mechanical polishing.

Material Removes Heavy Metal Ions From Water

NASA Technical Reports Server (NTRS)

Philipp, Warren H., Jr.; Street, Kenneth W.; Hill, Carol; Savino, Joseph M.

1995-01-01

New high capacity ion-exchange polymer material removes toxic metal cations from contaminated water. Offers several advantages. High sensitivities for such heavy metals as lead, cadmium, and copper and capable of reducing concentrations in aqueous solutions to parts-per-billion range. Removes cations even when calcium present. Material made into variety of forms, such as thin films, coatings, pellets, and fibers. As result, adapted to many applications to purify contaminated water, usually hard wherever found, whether in wastewater-treatment systems, lakes, ponds, industrial plants, or homes. Another important feature that adsorbed metals easily reclaimed by either destructive or nondestructive process. Other tests show ion-exchange polymer made inexpensively; easy to use; strong, flexible, not easily torn; and chemically stable in storage, in aqueous solutions, and in acidic or basic solution.

Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

PubMed

Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

2016-03-15

In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

Subsurface Damage in Polishing Process of Silicon Carbide Ceramic

PubMed Central

Gu, Yan; Zhu, Wenhui; Lin, Jieqiong; Lu, Mingming; Kang, Mingshuo

2018-01-01

Subsurface damage (SSD) in the polishing process of silicon carbide (SiC) ceramic presents one of the most significant challenges for practical applications. In this study, the theoretical models of SSD depth are established on the basis of the material removal mechanism and indentation fracture mechanics in the SiC ceramic polishing process. In addition, the three-dimensional (3D) models of single grit polishing are also developed by using the finite element simulation; thereby, the dynamic effects of different process parameters on SSD depth are analyzed. The results demonstrate that the material removal was mainly in brittle mode when the cutting depth was larger than the critical depth of the brittle material. The SSD depth increased as the polishing depth and abrasive grain size increased, and decreased with respect to the increase in polishing speed. The experimental results suggested a good agreement with the theoretical simulation results in terms of SSD depth as a function of polishing depth, spindle speed, and abrasive grain size. This study provides a mechanistic insight into the dependence of SSD on key operational parameters in the polishing process of SiC ceramic. PMID:29584694

Process for the removal of radium from acidic solutions containing same

DOEpatents

Scheitlin, F.M.

The invention is a process for the removal of radium from acidic aqueous solutions. In one aspect, the invention is a process for removing radium from an inorganic-acid solution. The process comprises contacting the solution with coal fly ash to effect adsorption of the radium on the ash. The radium-containing ash then is separated from the solution. The process is simple, comparatively inexpensive, and efficient. High radium-distribution coefficients are obtained even at room temperature. Coal fly ash is an inexpensive, acid-resistant, high-surface-area material which is available in large quantities throughout the United States. The invention is applicable, for example, to the recovery of /sup 226/Ra from nitric acid solutions which have been used to leach radium from uranium-mill tailings.

Nuclear criticality safety bounding analysis for the in-tank-precipitation (ITP) process, impacted by fissile isotopic weight fractions

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

Bess, C.E.

The In-Tank Precipitation process (ITP) receives High Level Waste (HLW) supernatant liquid containing radionuclides in waste processing tank 48H. Sodium tetraphenylborate, NaTPB, and monosodium titanate (MST), NaTi{sub 2}O{sub 5}H, are added for removal of radioactive Cs and Sr, respectively. In addition to removal of radio-strontium, MST will also remove plutonium and uranium. The majority of the feed solutions to ITP will come from the dissolution of supernate that had been concentrated by evaporation to a crystallized salt form, commonly referred to as saltcake. The concern for criticality safety arises from the adsorption of U and Pt onto MST. If sufficientmore » mass and optimum conditions are achieved then criticality is credible. The concentration of u and Pt from solution into the smaller volume of precipitate represents a concern for criticality. This report supplements WSRC-TR-93-171, Nuclear Criticality Safety Bounding Analysis For The In-Tank-Precipitation (ITP) Process. Criticality safety in ITP can be analyzed by two bounding conditions: (1) the minimum safe ratio of MST to fissionable material and (2) the maximum fissionable material adsorption capacity of the MST. Calculations have provided the first bounding condition and experimental analysis has established the second. This report combines these conditions with canyon facility data to evaluate the potential for criticality in the ITP process due to the adsorption of the fissionable material from solution. In addition, this report analyzes the potential impact of increased U loading onto MST. Results of this analysis demonstrate a greater safety margin for ITP operations than the previous analysis. This report further demonstrates that the potential for criticality in the ITP process due to adsorption of fissionable material by MST is not credible.« less

Process for removing polymer-forming impurities from naphtha fraction

DOEpatents

Kowalczyk, D.C.; Bricklemyer, B.A.; Svoboda, J.J.

1983-12-27

Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment. 2 figs.

Process for removing polymer-forming impurities from naphtha fraction

DOEpatents

Kowalczyk, Dennis C.; Bricklemyer, Bruce A.; Svoboda, Joseph J.

1983-01-01

Polymer precursor materials are vaporized without polymerization or are removed from a raw naphtha fraction by passing the raw naphtha to a vaporization zone (24) and vaporizing the naphtha in the presence of a wash oil while stripping with hot hydrogen to prevent polymer deposits in the equipment.

Bioremediation of arsenic from water with citric acid cross-linked water hyacinth (E. crassipes) root powder.

PubMed

Gogoi, Pankaj; Adhikari, Pooja; Maji, Tarun K

2017-08-01

A green and novel approach was demonstrated for successful remediation of arsenic from contaminated water by citric acid (CA) cross-linked water hyacinth root powder (RP). Different analytical techniques were used to investigate the binding and structural properties of prepared materials. Titanium dioxide played a significant role in the cross-linking process. Incorporation of CA into RP enhanced its integrity, and thus removal efficiency remained unaffected after several cyclic runs. Also the turbidity which formed due to treatment with uncross-linked RP was reduced to below the permissible limit. Effect of the amount of CA, material dose, treatment time, initial ion concentration, and pH were investigated. Use of 10% (w/w) CA was found to be sufficient to bring down the turbidity of the treated water below 2.5 nephelometric turbidity unit (NTU) without hampering the removal capacity/rate. A material dose of 5 g/L removed successfully total inorganic arsenic concentration to below 10 μg/L. The sorption process could be reasonably explained by Langmuir isotherm, and the maximum adsorption capacity was found to be 28 μg of arsenic/g. The material was found to be more efficient at acidic pH (pH ZPC  = 6.72). The sorption process was governed by a pseudo-second-order kinetic model.

Strategies for gallium removal after focused ion beam patterning of ferroelectric oxide nanostructures

NASA Astrophysics Data System (ADS)

Schilling, A.; Adams, T.; Bowman, R. M.; Gregg, J. M.

2007-01-01

As part of a study into the properties of ferroelectric single crystals at nanoscale dimensions, the effects that focused ion beam (FIB) processing can have, in terms of structural damage and ion implantation, on perovskite oxide materials has been examined, and a post-processing procedure developed to remove such effects. Single crystal material of the perovskite ferroelectric barium titanate (BaTiO3) has been patterned into thin film lamellae structures using a FIB microscope. Previous work had shown that FIB patterning induced gallium impregnation and associated creation of amorphous layers in a surface region of the single crystal material some 20 nm thick, but that both recrystallization and expulsion of gallium could be achieved through thermal annealing in air. Here we confirm this observation, but find that thermally induced gallium expulsion is associated with the formation of gallium-rich platelets on the surface of the annealed material. These platelets are thought to be gallium oxide. Etching using nitric and hydrochloric acids had no effect on the gallium-rich platelets. Effective platelet removal involved thermal annealing at 700 °C for 1 h in a vacuum followed by 1 h in oxygen, and then a post-annealing low-power plasma clean in an Ar/O atmosphere. Similar processing is likely to be necessary for the full recovery of post FIB-milled nanostructures in oxide ceramic systems in general.

A post-processing study on aluminum surface by fiber laser: Removing face milling patterns

NASA Astrophysics Data System (ADS)

Kayahan, Ersin

2018-05-01

The face milling process of the metal surface is a well-known machining process of using rotary cutters to remove material from a workpiece. Flat metal surfaces can be produced by a face milling process. However, in practice, visible, traced marks following the motion of points on the cutter's face are usually apparent. In this study, it was shown that milled patterns can be removed by means of 20 W fiber laser on the aluminum surface (AA7075). Experimental results also showed that roughened and hydrophobic surface can be produced with optimized laser parameters. It is a new approach to remove the patterns from the metal surface and can be explained through roughening by re-melting instead of ablation. The new method is a strong candidate to replace sandblasting the metal surface. It is also cheap and environmentally friendly.

Manufacturing and Machining Challenges of Hybrid Aluminium Metal Matix Composites

NASA Astrophysics Data System (ADS)

Baburaja, Kammuluri; Sainadh Teja, S.; Karthik Sri, D.; Kuldeep, J.; Gowtham, V.

2017-08-01

Manufacturing which involves material removal processes or material addition processes or material transformation processes. One or all the processes to obtain the final desired properties for a material with desired shape which meets the required precision and accuracy values for the expected service life of a material in working conditions. Researchers found the utility of aluminium to be the second largest after steel. Aluminium and its metal matrix composite possess wide applications in various applications in aerospace industry, automobile industry, Constructions and even in kitchen utensils. Hybrid Al-MMCconsist of two different materials, and one will be from organic origin along with the base material. In this paper an attempt is made to bring out the importance of utilization of aluminium and the challenges concerned in manufacturing and machining of hybrid aluminium MMC.

Halide removal from aqueous solution by novel silver-polymeric materials.

PubMed

A M S, Polo; I, Velo-Gala; M, Sánchez-Polo; U, von Gunten; J J, López-Peñalver; J, Rivera-Utrilla

2016-12-15

The objective of this study was to analyze the behavior of a new material, silver-doped polymeric cloth (Ag-cloth), in the removal of bromide and iodide from waters. Silver is immobilized on the cloth, guaranteeing selective adsorption of the halide ions as retained silver halides that therefore do not pass into the solution. Results indicate that Ag 0 reacts with H 2 O 2 in the first phases of the process, yielding Ag + and superoxide radical; however, as the process advances, this radical favors Ag + reduction. Increases in the concentration of H 2 O 2 augment the capacity of the Ag-cloth to remove halides from the medium up to a maximum concentration (55μM), above which the removal capacity remains constant (Xm≅1.3-1.8mg halide/g Ag-cloth). Thus, when there is excess H 2 O 2 in the medium, secondary competitive reactions that take place in the process guarantee a constant Ag + concentration, which defines the maximum adsorption capacity of Ag-cloth, reducing its ability to remove halides. Ag-cloth has a higher capacity to remove iodide than bromide, and the presence of organic matter or chloride reduces its capacity to remove iodide or bromide from water. The results obtained shown that the capacity of Ag 0 with H 2 O 2 significantly varies as a function of the medium pH from 1mg Br - /g Ag-cloth at very low pH to 1.6mg/g Ag-cloth at pH9. Copyright © 2016 Elsevier B.V. All rights reserved.

Sulfur-based autotrophic denitrification with eggshell for nitrate-contaminated synthetic groundwater treatment.

PubMed

Xu, Yaxian; Chen, Nan; Feng, Chuanping; Hao, Chunbo; Peng, Tong

2016-12-01

Eggshell is considered to be a waste and a significant quantity of eggshell waste is generated from food processing, baking and hatching industries. In this study, the effect of different sulfur/eggshell (w/w) ratios and temperatures was investigated to evaluate the feasibility of the sulfur-based autotrophic denitrification with eggshell (SADE) process for nitrate removal. The results showed eggshell can maintain a neutral condition in a range of pH 7.05-7.74 in the SADE process, and remove 97% of nitrate in synthetic groundwater. Compared with oyster shell and limestone, eggshell was found to be a desirable alkaline material for sulfur-based autotrophic denitrification (SAD) with no nitrite accumulation and insignificant sulfate production. Denitrification reaction was found to follow the first-order kinetic models (R(2) > .9) having nitrate removal rate constants of 0.85 and 0.93 d(-1) for raw eggshell and boiled eggshell, respectively. Sulfur/eggshell ratio of 2:3 provided the best efficiency on nitrate removal. Nitrate was removed completely by the SADE process at a low temperature of 15°C. Eggshell could be used for the SAD process due to its good effect for nitrate removal from groundwater.

Laser machining of explosives

DOEpatents

Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

2000-01-01

The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

Removal of Radiocesium from Food by Processing: Data Collected after the Fukushima Daiichi Nuclear Power Plant Accident - 13167

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

Uchida, Shigeo; Tagami, Keiko

Removal of radiocesium from food by processing is of great concern following the accident of TEPCO's Fukushima Daiichi Nuclear Power Plant accident. Foods in markets are monitored and recent monitoring results have shown that almost all food materials were under the standard limit concentration levels for radiocesium (Cs-134+137), that is, 100 Bq kg{sup -1} in raw foods, 50 Bq kg{sup -1} in baby foods, and 10 Bq kg{sup -1} in drinking water; those food materials above the limit cannot be sold. However, one of the most frequently asked questions from the public is how much radiocesium in food would bemore » removed by processing. Hence, information about radioactivity removal by processing of food crops native to Japan is actively sought by consumers. In this study, the food processing retention factor, F{sub r}, which is expressed as total activity in processed food divided by total activity in raw food, is reported for various types of corps. For white rice at a typical polishing yield of 90-92% from brown rice, the F{sub r} value range was 0.42-0.47. For leafy vegetable (indirect contamination), the average F{sub r} values were 0.92 (range: 0.27-1.2) after washing and 0.55 (range: 0.22-0.93) after washing and boiling. The data for some fruits are also reported. (authors)« less

Method and system for radioisotope generation

DOEpatents

Toth, James J.; Soderquist, Chuck Z.; Greenwood, Lawrence R.; Mattigod, Shas V.; Fryxell, Glen E.; O'Hara, Matthew J.

2014-07-15

A system and a process for producing selected isotopic daughter products from parent materials characterized by the steps of loading the parent material upon a sorbent having a functional group configured to selectively bind the parent material under designated conditions, generating the selected isotopic daughter products, and eluting said selected isotopic daughter products from the sorbent. In one embodiment, the process also includes the step of passing an eluent formed by the elution step through a second sorbent material that is configured to remove a preselected material from said eluent. In some applications a passage of the material through a third sorbent material after passage through the second sorbent material is also performed.

Bicarbonate of soda paint stripping process validation and material characterization

NASA Technical Reports Server (NTRS)

Haas, Michael N.

1995-01-01

The Aircraft Production Division at San Antonio Air Logistics Center has conducted extensive investigation into the replacement of hazardous chemicals in aircraft component cleaning, degreasing, and depainting. One of the most viable solutions is process substitution utilizing abrasive techniques. SA-ALC has incorporated the use of Bicarbonate of Soda Blasting as one such substitution. Previous utilization of methylene chloride based chemical strippers and carbon removal agents has been replaced by a walk-in blast booth in which we remove carbon from engine nozzles and various gas turbine engine parts, depaint cowlings, and perform various other functions on a variety of parts. Prior to implementation of this new process, validation of the process was performed, and materials and waste stream characterization studies were conducted. These characterization studies examined the effects of the blasting process on the integrity of the thin-skinned aluminum substrates, the effects of the process on both air emissions and effluent disposal, and the effects on the personnel exposed to the process.

Modeling and evaluating of surface roughness prediction in micro-grinding on soda-lime glass considering tool characterization

NASA Astrophysics Data System (ADS)

Cheng, Jun; Gong, Yadong; Wang, Jinsheng

2013-11-01

The current research of micro-grinding mainly focuses on the optimal processing technology for different materials. However, the material removal mechanism in micro-grinding is the base of achieving high quality processing surface. Therefore, a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography is proposed in this paper. The differences of material removal mechanism between convention grinding process and micro-grinding process are analyzed. Topography characterization has been done on micro-grinding tools which are fabricated by electroplating. Models of grain density generation and grain interval are built, and new predicting model of micro-grinding surface roughness is developed. In order to verify the precision and application effect of the surface roughness prediction model proposed, a micro-grinding orthogonally experiment on soda-lime glass is designed and conducted. A series of micro-machining surfaces which are 78 nm to 0.98 μm roughness of brittle material is achieved. It is found that experimental roughness results and the predicting roughness data have an evident coincidence, and the component variable of describing the size effects in predicting model is calculated to be 1.5×107 by reverse method based on the experimental results. The proposed model builds a set of distribution to consider grains distribution densities in different protrusion heights. Finally, the characterization of micro-grinding tools which are used in the experiment has been done based on the distribution set. It is concluded that there is a significant coincidence between surface prediction data from the proposed model and measurements from experiment results. Therefore, the effectiveness of the model is demonstrated. This paper proposes a novel method for predicting surface roughness in micro-grinding of hard brittle materials considering micro-grinding tool grains protrusion topography, which would provide significant research theory and experimental reference of material removal mechanism in micro-grinding of soda-lime glass.

Fabrication technology

NASA Astrophysics Data System (ADS)

1988-05-01

Many laboratory programs continue to need optical components of ever-increasing size and accuracy. Unfortunately, optical surfaces produced by the conventional sequence of grinding, lapping, and polishing can become prohibitively expensive. Research in the Fabrication Technology area focuses on methods of fabricating components with heretofore unrealized levels of precision. In FY87, researchers worked to determine the fundamental mechanical limits of material removal, experimented with unique material removal and deposition processes, developed servo systems for controlling the geometric position of ultraprecise machine tools, and advanced the ability to precisely measure contoured workpieces. Continued work in these areas will lead to more cost-effective processes to fabricate even higher quality optical components for advanced lasers and for visible, ultraviolet, and X-ray diagnostic systems.

Tracking changes in composition and amount of dissolved organic matter throughout drinking water treatment plants by comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry.

PubMed

Li, Chunmei; Wang, Donghong; Xu, Xiong; Xu, Meijia; Wang, Zijian; Xiao, Ruiyang

2017-12-31

Dissolved organic matter (DOM) can affect the performance of water treatment processes and produce undesirable disinfection by-products during disinfection. Several studies have been undertaken on the structural characterization of DOM, but its fate during drinking water treatment processes is still not fully understood. In this work, the nontargeted screening method of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) was used to reveal the detailed changes of different chemical classes of compounds in DOM during conventional and advanced drinking water treatment processes at three drinking water treatment plants in China. The results showed that when the dissolved organic carbon removal was low, shifts in the DOM composition could not be detected with the specific ultraviolet absorbance at 254nm, but the changes were clear in the three-dimensional fluorescence excitation-emission matrix or GC×GC-qMS analyses. Coagulation-sedimentation processes selectively removed 37-59% of the nitrogenous compounds, alcohols and aromatic hydrocarbons but increased the concentrations of halogen-containing compounds by 17-26% because of the contact time with chlorine in this step. Filtration was less efficient at removing DOM but preferentially removed 21-60% of the acids. However, other organic matter would be released from the filter (e.g., nitrogenous compounds, acids, and aromatic hydrocarbons). Biological activated carbon (BAC) treatment removed most of the compounds produced from ozonation, particularly ketones, alcohols, halogen-containing compounds and acids. However, it should be noted that certain highly polar or high molecular weight compounds not identified in this study might be released from the BAC bed. After the whole treatment processes, the concentrations of nitrogenous compounds, alcohols, alkenes, aromatic hydrocarbons and ketones were decreased more by the advanced treatment processes than by the conventional treatment processes. Alcohol and ketone removals were probably related to the reduction in protein-like materials. Alkane removal was probably related to the reduction in fulvic acid-like and humic acid-like materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Second Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor); Clark-Ingram, M. (Editor)

1997-01-01

The mandated elimination of CFC'S, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application, verification, compliant coatings including corrosion protection system and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.

Second Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Clark-Ingram, M.; Hessler, S. L.

1997-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.

Novel sorbents for environmental remediation

NASA Astrophysics Data System (ADS)

Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

2014-05-01

Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session on Novel sorbents for environmental remediation, will also be evaluated and presented.

Reliability analysis of nutrient removal from stormwater runoff with green sorption media under varying influent conditions.

PubMed

Jones, Jamie; Chang, Ni-Bin; Wanielista, Martin P

2015-01-01

To support nutrient removal, various stormwater treatment technologies have been developed via the use of green materials, such as sawdust, tire crumbs, sand, clay, sulfur, and limestone, as typical constituents of filter media mixes. These materials aid in the physiochemical sorption and precipitation of orthophosphates as well as in the biological transformation of ammonia, nitrates and nitrites. However, these processes are dependent upon influent conditions such as hydraulic residence time, influent orthophosphate concentrations, and other chemical species present in the inflow. This study aims to compare the physiochemical removal of orthophosphate by isotherm and column tests under differing influent conditions to realize the reliability of orthophosphate removal process with the aid of green sorption media. The green sorption media of interest in this study is composed of a 5:2:2:1 (by volume) mixture of cement sand, tire crumb, fine expanded clay, and limestone. Scenarios of manipulating the hydraulic residence time of the water from 18 min and 60 min, the influent dissolved phosphorus concentrations of 1.0 mg·L(-1) and 0.5 mg·L(-1), and influent water types of distilled and pond water, were all investigated in the column tests. Experimental data were compared with the outputs from the Thomas Model based on orthophosphate removal to shed light on the equilibrium condition versus kinetic situation. With ANOVA tests, significant differences were confirmed between the experimental data sets of the breakthrough curves in the column tests. SEM imaging analysis helps to deepen the understanding of pore structures and pore networks of meta-materials being used in the green sorption media. Life expectancy curves derived from the output of Thomas Model may be applicable for future system design of engineering processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Municipal waste processing apparatus

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

Mayberry, J L

1987-01-15

Municipal waste materials are processed by crushing the materials so that pieces of noncombustible material are smaller than a selected size and pieces of combustible material are larger than the selected size. The crushed materials are placed on a vibrating mesh screen conveyor belt having openings which pass the smaller, noncombustible pieces of material, but do not pass the larger, combustible pieces of material. Pieces of material which become lodged in the openings of the conveyor belt may be removed by cylindrical deraggers or pressurized air. The crushed materials may be fed onto the conveyor belt by a vibrating feedmore » plate which shakes the materials so that they tend to lie flat.« less

Analysis of the Material Removal Rate in Magnetic Abrasive Finishing of Thin Film Coated Pyrex Glass

NASA Astrophysics Data System (ADS)

Lee, Hee Hwan; Lee, Seoung Hwan

The material removal rate (MRR) during precision finishing/polishing is a key factor, which dictates the process performance. Moreover, the MRR or wear rate is closely related to the material/part reliability. For nanoscale patterning and/or planarization on nano-order thickness coatings, the prediction and in-process monitoring of the MRR is necessary, because the process is not characterizable due to size effects and material property/process condition variations as a result of the coating/substrate interactions. The purpose of this research was to develop a practical methodology for the prediction and in-process monitoring of MRR during nanoscale finishing of coated surfaces. Using a specially designed magnetic abrasive finishing (MAF) and acoustic emission (AE) monitoring setup, experiments were carried out on indium-zinc-oxide (IZO) coated Pyrex glasses. After a given polishing time interval, AFM indentation was conducted for each workpiece sample to measure the adhesion force variations of the coating layers (IZO), which are directly related to the MRR changes. The force variation and AE monitoring data were compared to the MRR calculated form the surface measurement (Nanoview) results. The experimental results demonstrate strong correlations between AFM indentation and MRR measurement data. In addition, the monitored AE signals show sensitivity of the material structure variations of the coating layer, as the polishing progresses.

Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

NASA Astrophysics Data System (ADS)

Stoughton, Hannah L.

For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

3D surface coordinate inspection of formed sheet material parts using optical measurement systems and virtual distortion compensation

NASA Astrophysics Data System (ADS)

Weckenmann, Albert A.; Gall, P.; Gabbia, A.

2005-02-01

Modern forming technology allows the production of highly sophisticated free form sheet material components, affording great flexibility to the design and manufacturing processes across a wide range of industries. This increased design and manufacturing potential places an ever growing demand on the accompanying inspection metrology. As a consequence of their surface shape, these parts underlie a reversible geometrical deformation caused by variations of the material and the manufacturing process, as well as by gravity. This distortion is removed during the assembly process, usually performed in automated robotic processes. For this reason, the part's tolerated parameters have to be inspected in a defined state, simulating the assembly process' boundary conditions. Thus, the inspection process chain consists of six steps: picking the workpiece up, manual fixation of the workpiece, tactile measurement of the surface's coordinates using a defined measurement strategy, manual removal of the fixation and removal of the workpiece from the inspection area. These steps are both laborious and time consuming (for example, the inspection of a car door can take up to a working day to complete). Using optical measuring systems and virtual distortion compensation, this process chain can be dramatically shortened. Optical measuring systems provide as a measurement result a point cloud representing a sample of all nearest surfaces in the measuring range containing the measurand. From this data, a surface model of the measurand can be determined, independent of its position in the measuring range. For thin sheet material parts an approximating finite element model can be deduced from such a surface model. By means of pattern recognition, assembly relevant features of the measurand can be identified and located on this model. Together with the boundary conditions given by the assembly process, the shape of the surface in its assembled state can be calculated using the finite elements method. In application these methods culminate in a shortened inspection process chain (which can now also be automated): picking the workpiece up, placing it in the measuring range, optical measurement, virtual distortion compensation and removal of the workpiece from the inspection area. This work discusses the methodology of our approach in detail and also provides and analyses experimental results. The underlying research was greatfully funded by the German Research Foundation (DFG).

Removal of chloride from MSWI fly ash.

PubMed

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han

2012-10-30

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. Copyright © 2012 Elsevier B.V. All rights reserved.

Comparison of the Alternative Asbestos Control Method and the NESHAP Method for Demolition of Asbestos-Containing Buildings

EPA Science Inventory

The Asbestos NESHAP (National Emission Standard for Hazardous Air Pollutants) requires the removal of all Regulated Asbestos-Containing Material (RACM) prior to the demolition of the buildings that fall under the auspices of the NESHAP. This removal process can be a costly and ti...

CAPSULE REPORT: EVAPORATION PROCESS

EPA Science Inventory

Evaporation has been an established technology in the metal finishing industry for many years. In this process, wastewaters containing reusable materials, such as copper, nickel, or chromium compounds are heated, producing a water vapor that is continuously removed and condensed....

Application of the base catalyzed decomposition process to treatment of PCB-contaminated insulation and other materials associated with US Navy vessels. Final report

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

Schmidt, A.J.; Zacher, A.H.; Gano, S.R.

1996-09-01

The BCD process was applied to dechlorination of two types of PCB-contaminated materials generated from Navy vessel decommissioning activities at Puget Sound Naval Shipyard: insulation of wool felt impregnated with PCB, and PCB-containing paint chips/debris from removal of paint from metal surfaces. The BCD process is a two-stage, low-temperature chemical dehalogenation process. In Stage 1, the materials are mixed with sodium bicarbonate and heated to 350 C. The volatilized halogenated contaminants (eg, PCBs, dioxins, furans), which are collected in a small volume of particulates and granular activated carbon, are decomposed by the liquid-phase reaction (Stage 2) in a stirred-tank reactor,more » using a high-boiling-point hydrocarbon oil as the reaction medium, with addition of a hydrogen donor, a base (NaOH), and a catalyst. The tests showed that treating wool felt insulation and paint chip wastes with Stage 2 on a large scale is feasible, but compared with current disposal costs for PCB-contaminated materials, using Stage 2 would not be economical at this time. For paint chips generated from shot/sand blasting, the solid-phase BCD process (Stage 1) should be considered, if paint removal activities are accelerated in the future.« less

TREATMENT OF STORMWATER BY NATURAL ORGANIC MATERIALS

EPA Science Inventory

The overall objective of this study was to evaluate the feasibility of using low-cost natural filter materials for stormwater (SW) treatment. Generic mulch, pine bark mulch, and processed jute were evaluated for metal and organic pollutant removal from actual SW samples collected...

Near-chip compliant layer for reducing perimeter stress during assembly process

DOEpatents

Schultz, Mark D.; Takken, Todd E.; Tian, Shurong; Yao, Yuan

2018-03-20

A heat source (single semiconductor chip or group of closely spaced semiconductor chips of similar height) is provided on a first side of a substrate, which substrate has on said first side a support member comprising a compressible material. A heat removal component, oriented at an angle to said heat source, is brought into proximity of said heat source such that said heat removal component contacts said support member prior to contacting said heat source. Said heat removal component is assembled to said heat source such that said support member at least partially absorbs global inequality of force that would otherwise be applied to said heat source, absent said support member comprising said compressible material.

Near-chip compliant layer for reducing perimeter stress during assembly process

DOEpatents

Schultz, Mark D.; Takken, Todd E.; Tian, Shurong; Yao, Yuan

2017-02-14

A heat source (single semiconductor chip or group of closely spaced semiconductor chips of similar height) is provided on a first side of a substrate, which substrate has on said first side a support member comprising a compressible material. A heat removal component, oriented at an angle to said heat source, is brought into proximity of said heat source such that said heat removal component contacts said support member prior to contacting said heat source. Said heat removal component is assembled to said heat source such that said support member at least partially absorbs global inequality of force that would otherwise be applied to said heat source, absent said support member comprising said compressible material.

Removal of radium from acidic solutions containing same by adsorption on coal fly ash

DOEpatents

Scheitlin, Frank M.

1984-01-01

The invention is a process for the removal of radium from acidic aqueous solutions. In one aspect, the invention is a process for removing radium from an inorganic-acid solution. The process comprises contacting the solution with coal fly ash to effect adsorption of the radium on the ash. The radium-containing ash then is separated from the solution. The process is simple, comparatively inexpensive, and efficient. High radium-distribution coefficients are obtained even at room temperature. Coal fly ash is an inexpensive, acid-resistant, high-surface-area material which is available in large quantities throughout the United States. The invention is applicable, for example, to the recovery of .sup.226 Ra from nitric acid solutions which have been used to leach radium from uranium-mill tailings.

Investigation of ion-beam machining methods for replicated x-ray optics

NASA Technical Reports Server (NTRS)

Drueding, Thomas W.

1996-01-01

The final figuring step in the fabrication of an optical component involves imparting a specified contour onto the surface. This can be expensive and time consuming step. The recent development of ion beam figuring provides a method for performing the figuring process with advantages over standard mechanical methods. Ion figuring has proven effective in figuring large optical components. The process of ion beam figuring removes material by transferring kinetic energy from impinging neutral particles. The process utilizes a Kaufman type ion source, where a plasma is generated in a discharge chamber by controlled electric potentials. Charged grids extract and accelerate ions from the chamber. The accelerated ions form a directional beam. A neutralizer outside the accelerator grids supplies electrons to the positive ion beam. It is necessary to neutralize the beam to prevent charging workpieces and to avoid bending the beam with extraneous electro-magnetic fields. When the directed beam strikes the workpiece, material sputters in a predicable manner. The amount and distribution of material sputtered is a function of the energy of the beam, material of the component, distance from the workpiece, and angle of incidence of the beam. The figuring method described here assumes a constant beam removal, so that the process can be represented by a convolution operation. A fixed beam energy maintains a constant sputtering rate. This temporally and spatially stable beam is held perpendicular to the workpiece at a fixed distance. For non-constant removal, corrections would be required to model the process as a convolution operation. Specific figures (contours) are achieved by rastering the beam over the workpiece at varying velocities. A unique deconvolution is performed, using series-derivative solution developed for the system, to determine these velocities.

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

Drueding, T.W.

The final figuring step in the fabrication of an optical component involves imparting a specified contour onto the surface. This can be expensive and time consuming step. The recent development of ion beam figuring provides a method for performing the figuring process with advantages over standard mechanical methods. Ion figuring has proven effective in figuring large optical components. The process of ion beam figuring removes material by transferring kinetic energy from impinging neutral particles. The process utilizes a Kaufman type ion source, where a plasma is generated in a discharge chamber by controlled electric potentials. Charged grids extract and acceleratemore » ions from the chamber. The accelerated ions form a directional beam. A neutralizer outside the accelerator grids supplies electrons to the positive ion beam. It is necessary to neutralize the beam to prevent charging workpieces and to avoid bending the beam with extraneous electro-magnetic fields. When the directed beam strikes the workpiece, material sputters in a predicable manner. The amount and distribution of material sputtered is a function of the energy of the beam, material of the component, distance from the workpiece, and angle of incidence of the beam. The figuring method described here assumes a constant beam removal, so that the process can be represented by a convolution operation. A fixed beam energy maintains a constant sputtering rate. This temporally and spatially stable beam is held perpendicular to the workpiece at a fixed distance. For non-constant removal, corrections would be required to model the process as a convolution operation. Specific figures (contours) are achieved by rastering the beam over the workpiece at varying velocities. A unique deconvolution is performed, using series-derivative solution developed for the system, to determine these velocities.« less

EFFECT OF SEPARATION PROCESSES ON THE FORMATION OF BROMINATED THMS

EPA Science Inventory

Separation treatment processes are being investigated as a way to control the formation of disinfection by-products (DBPs) in finished waters. These processes remove natural organic matter before a disinfection is applied, thus limiting the amount of material available to form D...

PROCESS OF FORMING POWDERED MATERIAL

DOEpatents

Glatter, J.; Schaner, B.E.

1961-07-14

A process of forming high-density compacts of a powdered ceramic material is described by agglomerating the powdered ceramic material with a heat- decompossble binder, adding a heat-decompossble lubricant to the agglomerated material, placing a quantity of the material into a die cavity, pressing the material to form a compact, pretreating the compacts in a nonoxidizing atmosphere to remove the binder and lubricant, and sintering the compacts. When this process is used for making nuclear reactor fuel elements, the ceramic material is an oxide powder of a fissionsble material and after forming, the compacts are placed in a cladding tube which is closed at its ends by vapor tight end caps, so that the sintered compacts are held in close contact with each other and with the interior wall of the cladding tube.

Thermal stir welding apparatus

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey (Inventor)

2011-01-01

A welding method and apparatus are provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

Near net shape processing: A necessity for advanced materials applications

NASA Technical Reports Server (NTRS)

Kuhn, Howard A.

1993-01-01

High quality discrete parts are the backbones for successful operation of equipment used in transportation, communication, construction, manufacturing, and appliances. Traditional shapemaking for discrete parts is carried out predominantly by machining, or removing unwanted material to produce the desired shape. As the cost and complexity of modern materials escalates, coupled with the expense and environmental hazards associated with handling of scrap, it is increasingly important to develop near net shape processes for these materials. Such processes involve casting of liquid materials, consolidation of powder materials, or deformation processing of simple solid shapes into the desired shape. Frequently, several of these operations may be used in sequence to produce a finished part. The processes for near net shape forming may be applied to any type of material, including metals, polymers, ceramics, and their composites. The ability to produce shapes is the key to implementation of laboratory developments in materials science into real world applications. This seminar presents an overview of near net shapemaking processes, some application examples, current developments, and future research opportunities.

Ultrafast dynamics of hard tissue ablation using fs-lasers.

PubMed

Domke, Matthias; Wick, Sebastian; Laible, Maike; Rapp, Stephan; Huber, Heinz P; Sroka, Ronald

2018-05-29

Several studies on hard tissue laser ablation demonstrated that ultrafast lasers enable precise material removal without thermal side effects. Although the principle ablation mechanisms have been thoroughly investigated, there are still open questions regarding the influence of material properties on transient dynamics. In this investigation, we applied pump-probe microscopy to record ablation dynamics of biomaterials with different tensile strengths (dentin, chicken bone, gallstone, kidney stones) at delay times between 1 ps and 10 μs. Transient reflectivity changes, pressure and shock wave velocities, and elastic constants were determined. The result revealed that absorption and excitation show the typical well-known transient behaviour of dielectric materials. We observed for all samples a photomechanical laser ablation process, where ultrafast expansion of the excited volume generates pressure waves leading to fragmentation around the excited region. Additionally, we identified tensile-strength-related differences in the size of ablated craters and ejected particles. The elastic constants derived were in agreement with literature values. In conclusion, pressure-wave-assisted material removal seems to be a general mechanism for hard tissue ablation with ultrafast lasers. This photomechanical process increases ablation efficiency and removes heated material, thus ultrafast laser ablation is of interest for clinical application where heating of the tissue must be avoided. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Utilisation of chip thickness models in grinding

NASA Astrophysics Data System (ADS)

Singleton, Roger

Grinding is now a well established process utilised for both stock removal and finish applications. Although significant research is performed in this field, grinding still experiences problems with burn and high forces which can lead to poor quality components and damage to equipment. This generally occurs in grinding when the process deviates from its safe working conditions. In milling, chip thickness parameters are utilised to predict and maintain process outputs leading to improved control of the process. This thesis looks to further the knowledge of the relationship between chip thickness and the grinding process outputs to provide an increased predictive and maintenance modelling capability. Machining trials were undertaken using different chip thickness parameters to understand how these affect the process outputs. The chip thickness parameters were maintained at different grinding wheel diameters for a constant productivity process to determine the impact of chip thickness at a constant material removal rate.. Additional testing using a modified pin on disc test rig was performed to provide further information on process variables. The different chip thickness parameters provide control of different process outputs in the grinding process. These relationships can be described using contact layer theory and heat flux partitioning. The contact layer is defined as the immediate layer beneath the contact arc at the wheel workpiece interface. The size of the layer governs the force experienced during the process. The rate of contact layer removal directly impacts the net power required from the system. It was also found that the specific grinding energy of a process is more dependent on the productivity of a grinding process rather than the value of chip thickness. Changes in chip thickness at constant material removal rate result in microscale changes in the rate of contact layer removal when compared to changes in process productivity. This is a significant piece of information in relation to specific grinding energy where conventional theory states it is primarily dependent on chip thickness..

Solid spherical glass particle impingement studies of plastic materials

NASA Technical Reports Server (NTRS)

Rao, P. V.; Young, S. G.; Buckley, D. H.

1983-01-01

Erosion experiments on polymethyl methacrylate (PMMA), polycarbonate, and polytetrafluoroethylene (PTFE) were conducted with spherical glass beads impacting at normal incidence. Optical and scanning electron microscopic studies and surface profile measurements were made on specimens at predetermined test intervals. During the initial stage of damage to PMMA and polycarbonate, material expands or builds up above the original surface. However, this buildup disappears as testing progresses. Little or no buildup was observed on PTFE. PTFE is observed to be the most resistant material to erosion and PMMA the least. At low impact pressures, material removal mechanisms are believed to be similar to those for metallic materials. However, at higher pressures, surface melting is indicated at the center of impact. Deformation and fatigue appear to play major roles in the material removal process with possible melting or softening.

Process and apparatus for adding and removing particles from pressurized reactors

DOEpatents

Milligan, John D.

1983-01-01

A method for adding and removing fine particles from a pressurized reactor is provided, which comprises connecting the reactor to a container, sealing the container from the reactor, filling the container with particles and a liquid material compatible with the reactants, pressurizing the container to substantially the reactor pressure, removing the seal between the reactor and the container, permitting particles to fall into or out of the reactor, and resealing the container from the reactor. An apparatus for adding and removing particles is also disclosed.

Fe and Mn removal from mining drainage using goaf filling materials obtained from coal mining process.

PubMed

Zhang, Liping; Chen, Aolei; Qu, Hongbin; Xu, Shouqiang; Zhang, Xue; He, Xuwen

2015-01-01

Coal gangue, sandy soil and clay (mass ratio 45:4:1) as goaf filling materials acquired from coal mining processes were applied to remove Fe and Mn effectively from mining drainage. The results of an adsorption kinetic study showed that the Fe adsorption equation was y=21.454y+8.4712, R2=0.9924 and the Mn adsorption equation was y=7.5409x+0.905, R2=0.9957. Meanwhile, the goaf filling materials had low desorption capacity (Fe 6.765 μg/g, Mn 1.52 μg/g) and desorption ratio (Fe 8.98%, Mn 11.04%). Experiments demonstrated that Fe and Mn from mining drainage could be removed stably at a flow rate of 1.2 L/min, Fe inlet concentration of less than 40 mg/L, Mn inlet concentration of less than 2 mg/L and neutral or alkaline conditions. During a procedure of continuous experiments, the effluent quality could meet the requirement of the 'Code for Engineering Design of Sewage Regeneration-GB503352-2002'. A real-application project using goaf filling materials to treat mining drainage in Shendong coal mine showed that the average cost per ton of mining drainage was about 0.55 RMB, which could bring about considerable economic benefit for coal mining enterprises.

Evaluation of Hydrogen Isotope Exchange Methodology on Adsorbents for Tritium Removal

DOE PAGES

Morgan, Gregg A.; Xiao, S. Xin

2015-03-06

The Savannah River National Laboratory has demonstrated a potential process that can be used to remove tritium from tritiated water using Pt-catalyzed molecular sieves. The process is an elemental isotope exchange process in which H 2 (when flowed through the molecular sieves) will exchange with the adsorbed water, D 2O, leaving H 2O adsorbed on the molecular sieves. Various formulations of catalyzed molecular sieve material were prepared using two different techniques, Pt-implantation and Pt-ion exchange. This technology has been demonstrated for a protium (H) and deuterium (D) system, but can also be used for the removal of tritium from contaminatedmore » water (T 2O, HTO, and DTO) using D 2 (or H 2)« less

Differential fluorescence EEMs can be used to assess treatability of DOM during drinking water production

NASA Astrophysics Data System (ADS)

Lavonen, Elin; Kothawala, Dolly; Tranvik, Lars; Köhler, Stephan

2014-05-01

Fluorescence spectroscopy has been widely used to characterize fluorescent dissolved organic matter (FDOM) in various waters including during drinking water production. Commonly used techniques for data treatment include peak picking, indexes calculated from 2D emission spectra and modelling of fluorescence components using parallel factor analysis (PARAFAC). However, peak picking and indexes only use limited information from the fluorescence EEMs and PARAFAC requires a larger dataset and experience to perform. Because DOM is a major issue in drinking water production, and personnel at water treatment plants usually have limited time for advanced analysis we have developed a simple way of assessing the treatability of DOM in different waters using differential fluorescence. With this approach the removed fraction of FDOM is calculated from samples taken before and after a particular treatment process and the percentage of removed material assessed. Samples have been collected from four large water treatment plants in Sweden and analyzed for 3Dfluorescence, absorbance and DOC. The selective removal of DOM during e.g. flocculation and slow sand filtration as well as differences in experienced treatability between the treatment plants was described with differential fluorescence. Chemical flocculation is selective towards FDOM with red-shifted emission across the entire EEM. Red-shift has earlier been connected to condensation (i.e. decrease in H/C) and positively correlated to molecular size indicating that larger, humified molecules are being preferentially removed. During the biological process of slow sand filtration compounds with blue-shifted emission are targeted demonstrating selective removal of more freshly produced, microbial material. Disinfection with UV/NH2Cl and NaOCl was found to only target material with protein-like fluorescence suggesting that FDOM of this nature could be responsible for unwanted consumption of disinfection agent. Targeted removal of this fraction prior to disinfection should optimize the process. Furthermore, the main process at all studied WTPs is flocculation and their experienced treatability could easily be explained through the percentage of FDOM with emission above 450 nm (p<0.0001).

Removal of bromates from water

NASA Astrophysics Data System (ADS)

Barlokova, D.; Ilavsky, J.; Marko, I.; Tkacova, J.

2017-10-01

Bromates are substances that are usually not present in drinking water. They are obtained by ozone disinfection in the presence of bromine ions in water, as an impurity of sodium hypochlorite, respectively. Because of their specific properties, bromates are classified as vary dangers substances, that can cause serious illnesses in humans. There are several technological processes that have been used to the removal of bromates from water at present. In this article, the removal of the bromates from water by the adsorption using various sorbent materials (activated carbon, zeolite, Klinopur-Mn, Bayoxide E33, GEH, Read-As and Activated alumina) are presented. The effectiveness of selected sorbent materials in the removal of bromates from drinking water moves in the interval from 10 to 40%. Based on laboratory results, the zeolite can be used to reduce the concentration of bromates in water.

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

Liu, Jia

Biorefineries convert biomass into many useful intermediates. For bio-based products to be used for fuel, energy, chemical, and many other applications, water needs to be removed from these aqueous products. Membrane separation technologies can significantly reduce separation energy consumption compared with conventional separation processes such as distillation. Nanoporous inorganic membranes have superior pervaporation performance with excellent organic fouling resistance. However, their commercial applications are limited due to high membrane costs and poor production reproducibility. A novel cost-effective inorganic membrane fabrication technology has been developed with low cost materials and using an advanced membrane fabrication technology. Low cost precursor material formulationmore » was successfully developed with desired material properties for membrane fabrication. An advanced membrane fabrication process was developed using the novel membrane materials to enable the fabrication of separation membranes of various geometries. The structural robustness and separation performance of the low cost inorganic membranes were evaluated. The novel inorganic membranes demonstrated high structural integrity and were effective in pervaporation removal of water.« less

Process for forming a long gas turbine engine blade having a main wall with a thin portion near a tip

DOEpatents

Campbell, Christian X; Thomaidis, Dimitrios

2014-05-13

A process is provided for forming an airfoil for a gas turbine engine involving: forming a casting of a gas turbine engine airfoil having a main wall and an interior cavity, the main wall having a wall thickness extending from an external surface of the outer wall to the interior cavity, an outer section of the main wall extending from a location between a base and a tip of the airfoil casting to the tip having a wall thickness greater than a final thickness. The process may further involve effecting movement, using a computer system, of a material removal apparatus and the casting relative to one another such that a layer of material is removed from the casting at one or more radial portions along the main wall of the casting.

Process waste assessment: Petroleum jelly removal from semiconductor die using trichloroethylene

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

Curtin, D.P.

The process analyzed involves non-production, laboratory environment use of trichloroethylene for the cleaning of semiconductor devices. The option selection centered on the replacement of the trichloroethylene with a non-hazardous material. This process waste assessment was performed as part of a pilot project.

Application of the Evacuated Canister System for Removing Residual Molten Glass From the West Valley Demonstration Project High-Level Waste Melter

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

May, Joseph J.; Dombrowski, David J.; Valenti, Paul J.

The principal mission of the West Valley Demonstration Project (WVDP) is to meet a series of objectives defined in the West Valley Demonstration Project Act (Public Law 96-368). Chief among these is the objective to solidify liquid high-level waste (HLW) at the WVDP site into a form suitable for disposal in a federal geologic repository. In 1982, the Secretary of Energy formally selected vitrification as the technology to be used to solidify HLW at the WVDP. One of the first steps in meeting the HLW solidification objective involved designing, constructing and operating the Vitrification (Vit) Facility, the WVDP facility thatmore » houses the systems and subsystems used to process HLW into stainless steel canisters of borosilicate waste-glass that satisfy waste acceptance criteria (WAC) for disposal in a federal geologic repository. HLW processing and canister production began in 1996. The final step in meeting the HLW solidification objective involved ending Vit system operations and shut ting down the Vit Facility. This was accomplished by conducting a discrete series of activities to remove as much residual material as practical from the primary process vessels, components, and associated piping used in HLW canister production before declaring a formal end to Vit system operations. Flushing was the primary method used to remove residual radioactive material from the vitrification system. The inventory of radioactivity contained within the entire primary processing system diminished by conducting the flushing activities. At the completion of flushing activities, the composition of residual molten material remaining in the melter (the primary system component used in glass production) consisted of a small quantity of radioactive material and large quantities of glass former materials needed to produce borosilicate waste-glass. A special system developed during the pre-operational and testing phase of Vit Facility operation, the Evacuated Canister System (ECS), was deployed at the West Valley Demonstration Project to remove this radioactively dilute, residual molten material from the melter before Vit system operations were brought to a formal end. The ECS consists of a stainless steel canister of the same size and dimensions as a standard HLW canister that is equipped with a special L-shaped snorkel assembly made of 304L stainless steel. Both the canister and snorkel assembly fit into a stainless steel cage that allows the entire canister assembly to be positioned over the melter as molten glass is drawn out by a vacuum applied to the canister. This paper describes the process used to prepare and apply the ECS to complete molten glass removal before declaring a formal end to Vit system operations and placing the Vit Facility into a safe standby mode awaiting potential deactivation.« less

Technology to Facilitate the Use of Impaired Waters in Cooling Towers

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

Colborn, Robert

The project goal was to develop an effective silica removal technology and couple that with existing electro-dialysis reversal (EDR) technology to achieve a cost effective treatment for impaired waters to allow for their use in the cooling towers of coal fired power plants. A quantitative target of the program was a 50% reduction in the fresh water withdrawal at a levelized cost of water of $3.90/Kgal. Over the course of the program, a new molybdenum-modified alumina was developed that significantly outperforms existing alumina materials in silica removal both kinetically and thermodynamically. The Langmuir capacity is 0.11g silica/g adsorbent. Moreover, amore » low cost recycle/regeneration process was discovered to allow for multiple recycles with minimal loss in activity. On the lab scale, five runs were carried out with no drop in performance between the second and fifth run in ability to absorb the silica from water. The Mo-modified alumina was successfully prepared on a multiple kilogram scale and a bench scale model column was used to remove 100 ppm of silica from 400 liters of simulated impaired water. Significant water savings would result from such a process and the regeneration process could be further optimized to reduce water requirements. Current barriers to implementation are the base cost of the adsorbent material and the fine powder form that would lead to back pressure on a large column. If mesoporous materials become more commonly used in other areas and the price drops from volume and process improvements, then our material would also lower in price because the amount of molybdenum needed is low and no additional processing is required. There may well be engineering solutions to the fine powder issue; in a simple concept experiment, we were able to pelletize our material with Boehmite, but lost performance due to a dramatic decrease in surface area.« less

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

Mohapatra, Pratyasha; Shaw, Santosh; Mendivelso-Perez, Deyny

Removing organics from hybrid nanostructures is a crucial step in many bottom-up materials fabrication approaches. It is usually assumed that calcination is an effective solution to this problem, especially for thin films. This assumption has led to its application in thousands of papers. Here in this paper, we show that this general assumption is incorrect by using a relevant and highly controlled model system consisting of thin films of ligand-capped ZrO 2 nanocrystals. After calcination at 800 °C for 12 h, while Raman spectroscopy fails to detect the ligands after calcination, elastic backscattering spectrometry characterization demonstrates that ~18% of themore » original carbon atoms are still present in the film. By comparison plasma processing successfully removes the ligands. Our growth kinetic analysis shows that the calcined materials have significantly different interfacial properties than the plasma-processed counterparts. Calcination is not a reliable strategy for the production of single-phase all-inorganic materials from colloidal nanoparticles.« less

Fluid extraction using carbon dioxide and organophosphorus chelating agents

DOEpatents

Smart, N.G.; Wai, C.M.; Lin, Y.; Kwang, Y.H.

1998-11-24

Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO{sub 2}, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO{sub 2} and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process. 1 fig.

Fluid extraction using carbon dioxide and organophosphorus chelating agents

DOEpatents

Smart, Neil G.; Wai, Chien M.; Lin, Yuehe; Kwang, Yak Hwa

1998-01-01

Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.

Removal of malachite green from aqueous solutions by electrocoagulation/peanut shell adsorption coupling in a batch system.

PubMed

Wang, Xiansheng; Ni, Jiaheng; Pang, Shuo; Li, Ying

2017-04-01

A electrocoagulation (EC)/peanut shell (PS) adsorption coupling technique was studied for the removal of malachite green (MG) in our present work. The addition of an appropriate PS dosage (5 g/L) resulted in remarkable increase in the removal efficiency of MG at lower current density and shorter operating time compared with the conventional EC process. The effect of current density, pH of MG solution, dosage of PS and initial concentration of MG were also investigated. The maximum removal efficiency of MG was 98% under optimum conditions in 5 min. And it was 23% higher than that in EC process. Furthermore, the unit energy demand (UED) and the unit electrode material demand (UEMD) were calculated and discussed. The results demonstrated that the EC/PS adsorption coupling method achieved a reduction of 94% UED and UEMD compared with EC process.

Treatment of leachate by electrocoagulation using aluminum and iron electrodes.

PubMed

Ilhan, Fatih; Kurt, Ugur; Apaydin, Omer; Gonullu, M Talha

2008-06-15

In this paper, treatment of leachate by electrocoagulation (EC) has been investigated in a batch process. The sample of leachate was supplied from Odayeri Landfill Site in Istanbul. Firstly, EC was compared with classical chemical coagulation (CC) process via COD removal. The first comparison results with 348 A/m2 current density showed that EC process has higher treatment performance than CC process. Secondly, effects of process variables such as electrode material, current density (from 348 to 631 A/m2), pH, treatment cost, and operating time for EC process are investigated on COD and NH4-N removal efficiencies. The appropriate electrode type search for EC provided that aluminum supplies more COD removal (56%) than iron electrode (35%) at the end of the 30 min operating time. Finally, EC experiments were also continued to determine the efficiency of ammonia removal, and the effects of current density, mixing, and aeration. All the findings of the study revealed that treatment of leachate by EC can be used as a step of a joint treatment.

Characterization of Atmospheric Pressure Plasma Torch and the Surface Interaction for Material Removal

NASA Astrophysics Data System (ADS)

McWilliams, Anthony Joseph

An atmospheric pressure plasma torch has been developed and characterized for removal of organic based coatings. The focus of the Strategic Environmental Research & Development Program (SERDP) project WP-1762, that funded the bulk of this dissertation work, is removal of paint from US Navy vessels. The goal is to develop a novel technology for coating removal that is capable of reducing the amount of environmental waste produced during the commonly used grit blasting process. The atmospheric pressure air plasma torch was identified as having the capacity to remove the paint systems while using only compressed air and electricity as a media-less removal system with drastically reduced waste generation. Any improvements to the existing technology need to be based on scientific knowledge and thus the plasma removal mechanisms or material warranted investigation. The removal of material does not show a strong relation to the plasma parameters of power, frequency, and gas flow, nor is there a strong relation to the presences of inorganic fillers impeding or altering the removal rates. The underlying removal mechanisms also do not show a strong correlation to the rotational temperature of the plasma but do show a strong correlation to the optical emission intensity. Primarily, the emission from atomic oxygen and molecular nitrogen were identified significant contributors and were investigated further. The plasma feed gas was then varied from the nitrogen and oxygen ratio present in ambient air to pure nitrogen to identify the effect of oxygen on the removal mechanism. From these experiments it was concluded that the oxygen present in air does contribute to the overall removal mechanism; however, it is not the sole contributing factor with the other major factor being nitrogen.

Optimization of removal function in computer controlled optical surfacing

NASA Astrophysics Data System (ADS)

Chen, Xi; Guo, Peiji; Ren, Jianfeng

2010-10-01

The technical principle of computer controlled optical surfacing (CCOS) and the common method of optimizing removal function that is used in CCOS are introduced in this paper. A new optimizing method time-sharing synthesis of removal function is proposed to solve problems of the removal function being far away from Gaussian type and slow approaching of the removal function error that encountered in the mode of planet motion or translation-rotation. Detailed time-sharing synthesis of using six removal functions is discussed. For a given region on the workpiece, six positions are selected as the centers of the removal function; polishing tool controlled by the executive system of CCOS revolves around each centre to complete a cycle in proper order. The overall removal function obtained by the time-sharing process is the ratio of total material removal in six cycles to time duration of the six cycles, which depends on the arrangement and distribution of the six removal functions. Simulations on the synthesized overall removal functions under two different modes of motion, i.e., planet motion and translation-rotation are performed from which the optimized combination of tool parameters and distribution of time-sharing synthesis removal functions are obtained. The evaluation function when optimizing is determined by an approaching factor which is defined as the ratio of the material removal within the area of half of the polishing tool coverage from the polishing center to the total material removal within the full polishing tool coverage area. After optimization, it is found that the optimized removal function obtained by time-sharing synthesis is closer to the ideal Gaussian type removal function than those by the traditional methods. The time-sharing synthesis method of the removal function provides an efficient way to increase the convergence speed of the surface error in CCOS for the fabrication of aspheric optical surfaces, and to reduce the intermediate- and high-frequency error.

Cantilever epitaxial process

DOEpatents

Ashby, Carol I.; Follstaedt, David M.; Mitchell, Christine C.; Han, Jung

2003-07-29

A process of growing a material on a substrate, particularly growing a Group II-VI or Group III-V material, by a vapor-phase growth technique where the growth process eliminates the need for utilization of a mask or removal of the substrate from the reactor at any time during the processing. A nucleation layer is first grown upon which a middle layer is grown to provide surfaces for subsequent lateral cantilever growth. The lateral growth rate is controlled by altering the reactor temperature, pressure, reactant concentrations or reactant flow rates. Semiconductor materials, such as GaN, can be produced with dislocation densities less than 10.sup.7 /cm.sup.2.

Magnetorheological finishing with chemically modified fluids for studying material removal of single-crystal ZnS

NASA Astrophysics Data System (ADS)

Salzman, S.; Romanofsky, H. J.; Clara, Y. I.; Giannechini, L. J.; West, Garrett J.; Lambropoulos, J. C.; Jacobs, S. D.

2013-09-01

Magnetorheological finishing (MRF) of polycrystalline, chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and zinc selenide (ZnSe) can leave millimeter-size artifacts on the part surface. These pebble-like features come from the anisotropic mechanical and chemical properties of the ceramic material and from the CVD growth process itself. The resulting surface texture limits the use of MRF for polishing aspheric and other complex shapes using these important infrared (IR) ceramics. An investigation of the individual contributions of chemistry and mechanics to polishing of other polycrystalline ceramics has been employed in the past to overcome similar material anisotropy problems. The approach taken was to study the removal process for the different single-crystal orientations that comprise the ceramic, making adjustments to mechanics (polishing abrasive type and concentration) and polishing slurry chemistry (primarily pH) to equalize the removal rate for all crystal orientations. Polishing with the modified slurry was shown to prevent the development of surface texture. Here we present mechanical (microhardness testing) and chemical (acid etching) studies performed on the four single-crystal orientations of ZnS: 100, 110, 111, and 311. We found that the (111) plane is 35% to 55% harder and 30% to 40% more resistant to chemical etching than the other three planes. This relatively high degree of variation in these properties can help to explain the surface texture developed from MRF of the polycrystalline material. Theoretical calculations of microhardness, planar, and bond densities are presented and compared with the experimental data. Here surface characterization of these single-crystal orientations of ZnS for material removal and roughness with chemically modified MR fluids at various pH levels between pH 4 and pH 6 are presented for the first time.

Low temperature vapor phase digestion of graphite

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

Pierce, Robert A.

2017-04-18

A method for digestion and gasification of graphite for removal from an underlying surface is described. The method can be utilized to remove graphite remnants of a formation process from the formed metal piece in a cleaning process. The method can be particularly beneficial in cleaning castings formed with graphite molding materials. The method can utilize vaporous nitric acid (HNO.sub.3) or vaporous HNO.sub.3 with air/oxygen to digest the graphite at conditions that can avoid damage to the underlying surface.

Chemical activation of gasification carbon residue for phosphate removal

NASA Astrophysics Data System (ADS)

Kilpimaa, Sari; Runtti, Hanna; Lassi, Ulla; Kuokkanen, Toivo

2012-05-01

Recycling of waste materials provides an economical and environmentally significant method to reduce the amount of waste. Bioash formed in the gasification process possesses a notable amount of unburned carbon and therefore it can be called a carbon residue. After chemical activation carbon residue could be use to replace activated carbon for example in wastewater purification processes. The effect of chemical activation process variables such as chemical agents and contact time in the chemical activation process were investigated. This study also explored the effectiveness of the chemically activated carbon residue for the removal of phosphate from an aqueous solution. The experimental adsorption study was performed in a batch reactor and the influence of adsorption time, initial phosphate concentration and pH was studied. Due to the carbon residue's low cost and high adsorption capacity, this type of waste has the potential to be utilised for the cost-effective removal of phosphate from wastewaters. Potential adsorbents could be prepared from these carbonaceous by-products and used as an adsorbent for phosphate removal.

Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor)

1995-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The Executive Summary of this Conference is published as NASA CP-3297.

A comparison of neural network architectures for the prediction of MRR in EDM

NASA Astrophysics Data System (ADS)

Jena, A. R.; Das, Raja

2017-11-01

The aim of the research work is to predict the material removal rate of a work-piece in electrical discharge machining (EDM). Here, an effort has been made to predict the material removal rate through back-propagation neural network (BPN) and radial basis function neural network (RBFN) for a work-piece of AISI D2 steel. The input parameters for the architecture are discharge-current (Ip), pulse-duration (Ton), and duty-cycle (τ) taken for consideration to obtained the output for material removal rate of the work-piece. In the architecture, it has been observed that radial basis function neural network is comparatively faster than back-propagation neural network but logically back-propagation neural network results more real value. Therefore BPN may consider as a better process in this architecture for consistent prediction to save time and money for conducting experiments.

Occurrence and removal of microbial indicators from municipal wastewaters by nine different MBR systems.

PubMed

Hirani, Zakir M; Decarolis, James F; Lehman, Geno; Adham, Samer S; Jacangelo, Joseph G

2012-01-01

Nine different membrane bioreactor (MBR) systems with different process configurations (submerged and external), membrane geometries (hollow-fiber, flat-sheet, and tubular), membrane materials (polyethersulfone (PES), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE)) and membrane nominal pore sizes (0.03-0.2 μm) were evaluated to assess the impact of influent microbial concentration, membrane pore size and membrane material and geometries on removal of microbial indicators by MBR technology. The log removal values (LRVs) for microbial indicators increased as the influent concentrations increased. Among the wide range of MBR systems evaluated, the total and fecal coliform bacteria and indigenous MS-2 coliphage were detected in 32, 9 and 15% of the samples, respectively; the 50th percentile LRVs were measured at 6.6, 5.9 and 4.5 logs, respectively. The nominal pore sizes of the membranes, membrane materials and geometries did not show a strong correlation with the LRVs.

Fabrication of diverse pH-sensitive functional mesoporous silica for selective removal or depletion of highly abundant proteins from biological samples.

PubMed

Wang, Jiaojiao; Lan, Jingfeng; Li, Huihui; Liu, Xiaoyan; Zhang, Haixia

2017-01-01

In proteomic studies, poor detection of low abundant proteins is a major problem due to the presence of highly abundant proteins. Therefore, the specific removal or depletion of highly abundant proteins prior to analysis is necessary. In response to this problem, a series of pH-sensitive functional mesoporous silica materials composed of 2-(diethylamino)ethyl methacrylate and methacrylic acid units were designed and synthesized via atom transfer radical polymerization. These functional mesoporous silica materials were characterized and their ability for adsorption and separation of proteins was evaluated. Possessing a pH-sensitive feature, the synthesized functional materials showed selective adsorption of some proteins in aqueous or buffer solutions at certain pH values. The specific removal of a particular protein from a mixed protein solution was subsequently studied. The analytical results confirmed that all the target proteins (bovine serum albumin, ovalbumin, and lysozyme) can be removed by the proposed materials from a five-protein mixture in a single operation. Finally, the practical application of this approach was also evaluated by the selective removal of certain proteins from real biological samples. The results revealed that the maximum removal efficiencies of ovalbumin and lysozyme from egg white sample were obtained as 99% and 92%, respectively, while the maximum removal efficiency of human serum albumin from human serum sample was about 80% by the proposed method. It suggested that this treatment process reduced the complexity of real biological samples and facilitated the identification of hidden proteins in chromatograms. Copyright © 2016 Elsevier B.V. All rights reserved.

Deterministic Computer-Controlled Polishing Process for High-Energy X-Ray Optics

NASA Technical Reports Server (NTRS)

Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

2010-01-01

A deterministic computer-controlled polishing process for large X-ray mirror mandrels is presented. Using tool s influence function and material removal rate extracted from polishing experiments, design considerations of polishing laps and optimized operating parameters are discussed

SEPARATIONS RESEARCH AT THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY - TOWARDS RECOVERY OF VOCS AND METALS USING MEMBRANES AND ADSORPTION PROCESSES

EPA Science Inventory

The USEPA's National Risk Management Research Laboratory is investigating new separations materials and processes for removal and recovery of volatile organic compounds (VOCs) and toxic metals from wastestreams and industrial process streams. Research applying membrane-based perv...

Process to make core-shell structured nanoparticles

DOEpatents

Luhrs, Claudia; Phillips, Jonathan; Richard, Monique N

2014-01-07

Disclosed is a process for making a composite material that contains core-shell structured nanoparticles. The process includes providing a precursor in the form of a powder a liquid and/or a vapor of a liquid that contains a core material and a shell material, and suspending the precursor in an aerosol gas to produce an aerosol containing the precursor. In addition, the process includes providing a plasma that has a hot zone and passing the aerosol through the hot zone of the plasma. As the aerosol passes through the hot zone of the plasma, at least part of the core material and at least part of the shell material in the aerosol is vaporized. Vapor that contains the core material and the shell material that has been vaporized is removed from the hot zone of the plasma and allowed to condense into core-shell structured nanoparticles.

Microbially mediated clinoptilolite regeneration in a multifunctional permeable reactive barrier used to remove ammonium from landfill leachate contamination: laboratory column evaluation.

PubMed

Nooten, Thomas Van; Diels, Ludo; Bastiaens, Leen

2010-05-01

This study focuses on multifunctional permeable reactive barrier (multibarrier) technology, combining microbial degradation and abiotic ion exchange processes for removal of ammonium from landfill leachate contamination. The sequential multibarrier concept relies on the use of a clinoptilolite-filled buffer compartment to ensure a robust ammonium removal in case of temporary insufficient microbial activities. An innovative strategy was developed to allow in situ clinoptilolite regeneration. Laboratory-scale clinoptilolite-filled columns were first saturated with ammonium, using real landfill leachate as well as synthetic leachates as feed media. Other inorganic metal cations, typically present in landfill leachate, had a detrimental influence on the ammonium removal capacity by competing for clinoptilolite exchange sites. On the other hand, the metals had a highly favorable impact on regeneration of the saturated material. Feeding the columns with leachate deprived from ammonium (e.g., by microbial nitrification in an upgradient compartment), resulted in a complete release of the previously sorbed ammonium from the clinoptilolite, due to exchange with metal cations present in the leachate. The released ammonium is then available for microbial consumption in a downgradient compartment. The regeneration process resulted in a slightly increased ammonium exchange capacity afterward. The described strategy throws a new light on sustainable use of sorption materials for in situ groundwater remediation, by avoiding the need for material replacement and the use of external chemical regenerants.

Recovery of nitrogen from saponification wastewater by struvite precipitation.

PubMed

Huang, Haiming; Xiao, Xianming; Yang, Liping; Yan, Bo

2010-01-01

In general, saponification wastewater produced from the separation process of rare-earth elements contains high ammonium concentration. In this study, a series of experiments were conducted to investigate the parameters to enhance the struvite precipitation potential for ammonium removal from the wastewater having an ammonium concentration of 4,100 mg/L. Experimental results showed that increasing the dose and grain size of pre-formed struvite, which was added as the seeding material in struvite reaction, could increase ammonium removal. The removal efficiency increased 7.6% when the dose of pre-formed struvite with crystal grain size range of 0.098-0.150 mm increased from 0 g/L to 60 g/L. Additionally, struvite precipitation was tested with the intermittent addition of magnesium and phosphate to utilize the struvite crystals formed during the reaction process as the seeding material for the subsequent reaction. The results revealed that intermittently adding magnesium 7 times effectively enhanced ammonium removal by around 8%, which was equivalent to that of using pre-formed struvite as the seeding material. Furthermore, the chemical composition of the struvite recovered with intermittent addition of magnesium was characterized, showing the struvite could be used as fertilizer. An economic evaluation indicated that intermittent addition of magnesium 7 times can save 13.4% cost for recovering per kg NH(4)(+) compared to that of bulk addition.

Comparative evaluation of low cost materials as constructed wetland filling media

NASA Astrophysics Data System (ADS)

Pinho, Henrique J. O.; Vaz, Mafalda M.; Mateus, Dina M. R.

2017-11-01

Three waste materials from civil construction activities were assessed as low cost alternative filling materials used in Constructed Wetlands (CW). CW are green processes for wastewater treatment, whose design includes an appropriate selection of vegetation and filling material. The sustainability of such processes may be incremented using recovered wastes as filling materials. The abilities of the materials to support plant growth and to contribute to pollutants removal from wastewater were assessed and compared to expanded clay, a filling usually used in CW design. Statistical analysis, using one-way ANOVA and Welch's ANOVA, demonstrate that limestone fragments are a better choice of filling material than brick fragments and basalt gravel.

4-chlorophenol removal from water using graphite and graphene oxides as photocatalysts.

PubMed

Bustos-Ramírez, Karina; Barrera-Díaz, Carlos Eduardo; De Icaza-Herrera, Miguel; Martínez-Hernández, Ana Laura; Natividad-Rangel, Reyna; Velasco-Santos, Carlos

2015-01-01

Graphite and graphene oxides have been studied amply in the last decade, due to their diverse properties and possible applications. Recently, their functionality as photocatalytic materials in water splitting was reported. Research in these materials is increasing due to their band gap values around 1.8-4 eV, and therefore, these are comparable with other photocatalysts currently used in heterogeneous photocatalytic processes. Thus, this research reports the photocatalytic effectiveness of graphite oxide (GO) and graphene oxide (GEO) in the degradation of 4-chlorophenol (4-CP) in water. Under the conditions defined for this research, 92 and 97% of 4-CP were degraded with GO and GEO respectively, also 97% of total organic carbon was removed. In addition, by-products of 4-CP that produce a yellow solution obtained only using photolysis are eliminated by photocatalyst process with GO and GEO. The degradation of 4-CP was monitored by UV-Vis spectroscopy, High Performance Liquid Chromatography (HPLC) and Chemical Oxygen Demand (COD). Thus, photocatalytic activity to remove 4-CP from water employing GO and GEO without doping is successfully showed, and therefore, a new gate in research for these materials is opened.

Analysis of machining damage in engineering ceramics by fracture mechanics, fractography and x-ray diffraction

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

Hollstein, T.; Pfeiffer, W.; Rombach, M.

1996-12-31

The cost for final machining covers a significant percentage of the whole cost of a ceramic component. This is due to the difficult machining of the high performance ceramics. The high values of hardness and wear resistance, which are desired in many applications, hinder the process of machining. Only a few machining procedures are applicable to engineering ceramics e.g. grinding, polishing or ultrasonic lapping, and the rate of material removal is considerably lower than for metals. In addition crack generation in the surface regions during machining is easily possible due to the brittleness of the ceramics. The material removal duringmore » grinding, which is the most important machining procedure of engineering ceramics, takes place mainly by brittle fracture processes but also by ductile material removal. The complex stress conditions in the work piece below or in the vicinity of the grinding grits lead to a variability of cracks and crack systems like median cracks, lateral cracks or radial cracks, which extend in general {le} 50 {mu}m and which lead to the strength anisotropy of ground ceramics, if certain grinding parameters are used e.g..« less

Laser comminution of submerged samples

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

Mariella, R. Jr.; Rubenchik, A.; Norton, M.

With the long-term goal in mind of investigating possible designs for a 'universal, solid-sample comminution technique' for elemental analysis of debris and rubble, we have studied pulsed-laser ablation of solid samples that were submerged in water. Using 351-nm, 15-ns laser pulses with energy between 1 J and 0.35 J, intensities between 500 MW/cm{sup 2} and 30 MW/cm{sup 2}, and samples of broken rock [quartzite] and concrete debris, we have observed conditions in which the laser-driven process can remove material from the solid target substrate, dissolving it and/or converting it into ultrafine particles in a controlled manner. Our study used impure,more » non-metallic substrates and investigated both the rate of material removal as well as the size distribution of particles that were ablated from the process. We studied ablation at lower regimes of intensity and fluence [below 100 MW/cm{sup 2} and 0.4 J/cm{sup 2}, respectively] than has previously attracted attention and discovered that there appears to be a new regime for energy-efficient material removal [Q* < 4000 J/g, for quartzite and <2000 J/g for concrete] and for the generation of ultrafine particles.« less

Efficacy of reactive mineral-based sorbents for phosphate, bacteria, nitrogen and TOC removal--column experiment in recirculation batch mode.

PubMed

Nilsson, Charlotte; Lakshmanan, Ramnath; Renman, Gunno; Rajarao, Gunaratna Kuttuva

2013-09-15

Two mineral-based materials (Polonite and Sorbulite) intended for filter wells in on-site wastewater treatment were compared in terms of removal of phosphate (PO4-P), total inorganic nitrogen (TIN), total organic carbon (TOC) and faecal indicator bacteria (Escherichia coli and Enterococci). Using an innovative, recirculating system, septic tank effluent was pumped at a hydraulic loading rate of 3000 L m(2) d(-1) into triplicate bench-scale columns of each material over a 90-day period. The results showed that Polonite performed better with respect to removal of PO4-P, retaining on average 80% compared with 75% in Sorbulite. This difference was attributed to higher CaO content in Polonite and its faster dissolution. Polonite also performed better in terms of removal of bacteria because of its higher pH value. The total average reduction in E. coli was 60% in Polonite and 45% in Sorbulite, while for Enterococci the corresponding value was 56% in Polonite and 34% in Sorbulite. Sorbulite removed TIN more effectively, with a removal rate of 23%, while Polonite removed 11% of TIN, as well as TOC. Organic matter (measured as TOC) was accumulated in the filter materials but was also released periodically. The results showed that Sorbulite could meet the demand in removing phosphate and nitrogen with reduced microbial release from the wastewater treatment process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Property-process relations in simulated clinical abrasive adjusting of dental ceramics.

PubMed

Yin, Ling

2012-12-01

This paper reports on property-process correlations in simulated clinical abrasive adjusting of a wide range of dental restorative ceramics using a dental handpiece and diamond burs. The seven materials studied included four mica-containing glass ceramics, a feldspathic porcelain, a glass-infiltrated alumina, and a yttria-stabilized tetragonal zirconia. The abrasive adjusting process was conducted under simulated clinical conditions using diamond burs and a clinical dental handpiece. An attempt was made to establish correlations between process characteristics in terms of removal rate, chipping damage, and surface finish and material mechanical properties of hardness, fracture toughness and Young's modulus. The results show that the removal rate is mainly a function of hardness, which decreases nonlinearly with hardness. No correlations were noted between the removal rates and the complex relations of hardness, Young's modulus and fracture toughness. Surface roughness was primarily a linear function of diamond grit size and was relatively independent of materials. Chipping damage in terms of the average chipping width decreased with fracture toughness except for glass-infiltrated alumina. It also had higher linear correlations with critical strain energy release rates (R²=0.66) and brittleness (R²=0.62) and a lower linear correlation with indices of brittleness (R²=0.32). Implications of these results can provide guidance for the microstructural design of dental ceramics, optimize performance, and guide the proper selection of technical parameters in clinical abrasive adjusting conducted by dental practitioners. Copyright © 2012 Elsevier Ltd. All rights reserved.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, S.; Wong, C.F.; Buckley, L.P.

1994-11-22

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, Sivaraman; Wong, Chi F.; Buckley, Leo P.

1994-01-01

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Highly efficient removal of ammonia nitrogen from wastewater by dielectrophoresis-enhanced adsorption.

PubMed

Liu, Dongyang; Cui, Chenyang; Wu, Yanhong; Chen, Huiying; Geng, Junfeng; Xia, Jianxin

2018-01-01

A new approach, based on dielectrophoresis (DEP), was developed in this work to enhance traditional adsorption for the removal of ammonia nitrogen (NH 3 -N) from wastewater. The factors that affected the removal efficiency were systematically investigated, which allowed us to determine optimal operation parameters. With this new method we found that the removal efficiency was significantly improved from 66.7% by adsorption only to 95% by adsorption-DEP using titanium metal mesh as electrodes of the DEP and zeolite as the absorbent material. In addition, the dosage of the absorbent/zeolite and the processing time needed for the removal were greatly reduced after the introduction of DEP into the process. In addition, a very low discharge concentration (C, 1.5 mg/L) of NH 3 -N was achieved by the new method, which well met the discharge criterion of C < 8 mg/L (the emission standard of pollutants for rare earth industry in China).

Three-dimensional numerical simulation during laser processing of CFRP

NASA Astrophysics Data System (ADS)

Ohkubo, Tomomasa; Sato, Yuji; Matsunaga, Ei-ichi; Tsukamoto, Masahiro

2017-09-01

We performed three-dimensional numerical simulation about laser processing of carbon-fiber-reinforced plastic (CFRP) using OpenFOAM as libraries of finite volume method (FVM). Although a little theoretical or numerical studies about heat affected zone (HAZ) formation were performed, there is no research discussing how HAZ is generated considering time development about removal of each material. It is important to understand difference of removal speed of carbon fiber and resin in order to improve quality of cut surface of CFRP. We demonstrated how the carbon fiber and resin are removed by heat of ablation plume by our simulation. We found that carbon fiber is removed faster than resin at first stage because of the difference of thermal conductivity, and after that, the resin is removed faster because of its low combustion temperature. This result suggests the existence of optimal contacting time of the laser ablation and kerf of the target.

Granular activated carbon for removal of organic matter and turbidity from secondary wastewater.

PubMed

Hatt, J W; Germain, E; Judd, S J

2013-01-01

A range of commercial granular activated carbon (GAC) media have been assessed as pretreatment technologies for a downstream microfiltration (MF) process. Media were assessed on the basis of reduction in both organic matter and turbidity, since these are known to cause fouling in MF membranes. Isotherm adsorption analysis through jar testing with supplementary column trials revealed a wide variation between the different adsorbent materials with regard to organics removal and adsorption kinetics. Comparison with previous work using powdered activated carbon (PAC) revealed that for organic removal above 60% the use of GAC media incurs a significantly lower carbon usage rate than PAC. All GACs tested achieved a minimum of 80% turbidity removal. This combination of turbidity and organic removal suggests that GAC would be expected to provide a significant reduction in fouling of a downstream MF process with improved product water quality.

Catalytic biomass pyrolysis process

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

Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.

Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

Assessment of some straw-derived materials for reducing the leaching potential of Metribuzin residues in the soil

NASA Astrophysics Data System (ADS)

Cara, Irina Gabriela; Trincă, Lucia Carmen; Trofin, Alina Elena; Cazacu, Ana; Ţopa, Denis; Peptu, Cătălina Anişoara; Jităreanu, Gerard

2015-12-01

Biomass (straw waste) can be used as raw to obtain materials for herbicide removal from wastewater. These by-products have some important advantages, being environmentally friendly, easily available, presenting low costs, and requiring little processing to increase their adsorptive capacity. In the present study, some materials derived from agricultural waste (wheat, corn and soybean straw) were investigated as potential adsorbents for metribuzin removal from aqueous solutions. The straw wastes were processed by grinding, mineralisation (850 °C) and KOH activation in order to improve their functional surface activity. The materials surface characteristics were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The adsorbents capacity was evaluated using batch sorption tests and liquid chromatography coupled with mass spectrometry for herbicide determination. For adsorption isotherms, the equilibrium time considered was 3 h. The experimental adsorption data were modelled by Freundlich and Langmuir models. The activated straw and ash-derived materials from wheat, corn and soybean increased the adsorption capacity of metribuzin with an asymmetrical behaviour. Overall, our results sustain that activated ash-derived from straw and activated straw materials can be a valuable solution for reducing the leaching potential of metribuzin through soil.

Ultrashort pulse laser machining of metals and alloys

DOEpatents

Perry, Michael D.; Stuart, Brent C.

2003-09-16

The invention consists of a method for high precision machining (cutting, drilling, sculpting) of metals and alloys. By using pulses of a duration in the range of 10 femtoseconds to 100 picoseconds, extremely precise machining can be achieved with essentially no heat or shock affected zone. Because the pulses are so short, there is negligible thermal conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond approximately 0.1-1 micron (dependent upon the particular material) from the laser machined surface. Due to the short duration, the high intensity (>10.sup.12 W/cm.sup.2) associated with the interaction converts the material directly from the solid-state into an ionized plasma. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces with negligible redeposition either within the kerf or on the surface. Since there is negligible heating beyond the depth of material removed, the composition of the remaining material is unaffected by the laser machining process. This enables high precision machining of alloys and even pure metals with no change in grain structure.

Resource Recovery and Reuse: Recycled Magnetically Separable Iron-based Catalysts for Phosphate Recovery and Arsenic Removal

EPA Science Inventory

Environmentally friendly processes that aid human and environmental health include recovering, recycling, and reusing limited natural resources and waste materials. In this study, we re-used Iron-rich solid waste materials from water treatment plants to synthesize magnetic iron-o...

Identification of Sources of Endotoxin Exposure as Input for Effective Exposure Control Strategies.

PubMed

van Duuren-Stuurman, Birgit; Gröllers-Mulderij, Mariska; van de Runstraat, Annemieke; Duisterwinkel, Anton; Terwoert, Jeroen; Spaan, Suzanne

2018-02-13

Aim of the present study is to investigate the levels of endotoxins on product samples from potatoes, onions, and seeds, representing a relevant part of the agro-food industry in the Netherlands, to gather valuable insights in possibilities for exposure control measures early in the process of industrial processing of these products. Endotoxin levels on 330 products samples from companies representing the potato, onion, and seed (processing) industry (four potato-packaging companies, five potato-processing companies, five onion-packaging companies, and four seed-processing companies) were assessed using the Limulus Amboecyte Lysate (LAL) assay. As variation in growth conditions (type of soil, growth type) and product characteristics (surface roughness, dustiness, size, species) are assumed to influence the level of endotoxin on products, different types, and growth conditions were considered when collecting the samples. Additionally, waste material, rotten products, felt material (used for drying), and process water were collected. A large variation in the endotoxin levels was found on samples of potatoes, onions, and seeds (overall geometric standard deviation 17), in the range between 0.7 EU g-1 to 16400000 EU g-1. The highest geometric mean endotoxin levels were found in plant material (319600 EU g-1), followed by soil material (49100 EU g-1) and the outer side of products (9300 EU g-1), indicating that removal of plant and soil material early in the process would be an effective exposure control strategy. The high levels of endotoxins found in the limited number of samples from rotten onions indicate that these rotten onions should also be removed early in the process. Mean endotoxin levels found in waste material (only available for seed processing) is similar to the level found in soil material, although the range is much larger. On uncleaned seeds, higher endotoxin levels were found than on cleaned seeds, indicating that cleaning processes are important control measures and also that the waste material should be handled with care. Although endotoxin levels in batches of to-be-processed potatoes, onions, and seeds vary quite dramatically, it could be concluded that rotten products, plant material, and waste material contain particularly high endotoxin levels. This information was used to propose control measures to reduce exposure to endotoxins of workers during the production process. © The Author(s) 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Liquefaction process for solid carbonaceous materials containing alkaline earth metal humates

DOEpatents

Epperly, William R.; Deane, Barry C.; Brunson, Roy J.

1982-01-01

An improved liquefaction process wherein wall scale and particulate agglomeration during the liquefaction of solid carbonaceous materials containing alkaline earth metal humates is reduced and/or eliminated by subjecting the solid carbonaceous materials to controlled cyclic cavitation during liquefaction. It is important that the solid carbonaceous material be slurried in a suitable solvent or diluent during liquefaction. The cyclic cavitation may be imparted via pressure cycling, cyclic agitation and the like. When pressure cycling or the like is employed an amplitude equivalent to at least 25 psia is required to effectively remove scale from the liquefaction vessel walls.

Advanced Materials and Manufacturing for Low-Cost, High-Performance Liquid Rocket Combustion Chambers

NASA Technical Reports Server (NTRS)

Williams, Brian E.; Arrieta, Victor M.

2013-01-01

A document describes the low-cost manufacturing of C103 niobium alloy combustion chambers, and the use of a high-temperature, oxidation-resistant coating that is superior to the standard silicide coating. The manufacturing process involved low-temperature spray deposition of C103 on removable plastic mandrels produced by rapid prototyping. Thin, vapor-deposited platinum-indium coatings were shown to substantially improve oxidation resistance relative to the standard silicide coating. Development of different low-cost plastic thrust chamber mandrel materials and prototyping processes (selective laser sintering and stereolithography) yielded mandrels with good dimensional accuracy (within a couple of mils) for this stage of development. The feasibility of using the kinetic metallization cold-spray process for fabrication of free-standing C1O3 thrusters on removable plastic mandrels was also demonstrated. The ambient and elevated temperature mechanical properties of the material were shown to be reasonably good relative to conventionally processed C103, but the greatest potential benefit is that coldsprayed chambers require minimal post-process machining, resulting in substantially lower machining and material costs. The platinum-iridium coating was shown to provide greatly increased oxidation resistance over the silicide when evaluated through oxyacetylene torch testing to as high as 300 F (= 150 C). The iridium component minimizes reaction with the niobium alloy chamber at high temperatures, and provides the high-temperature oxidation resistance needed at the throat.

Fabrication of ф 160 mm convex hyperbolic mirror for remote sensing instrument

NASA Astrophysics Data System (ADS)

Kuo, Ching-Hsiang; Yu, Zong-Ru; Ho, Cheng-Fang; Hsu, Wei-Yao; Chen, Fong-Zhi

2012-10-01

In this study, efficient polishing processes with inspection procedures for a large convex hyperbolic mirror of Cassegrain optical system are presented. The polishing process combines the techniques of conventional lapping and CNC polishing. We apply the conventional spherical lapping process to quickly remove the sub-surface damage (SSD) layer caused by grinding process and to get the accurate radius of best-fit sphere (BFS) of aspheric surface with fine surface texture simultaneously. Thus the removed material for aspherization process can be minimized and the polishing time for SSD removal can also be reduced substantially. The inspection procedure was carried out by using phase shift interferometer with CGH and stitching technique. To acquire the real surface form error of each sub aperture, the wavefront errors of the reference flat and CGH flat due to gravity effect of the vertical setup are calibrated in advance. Subsequently, we stitch 10 calibrated sub-aperture surface form errors to establish the whole irregularity of the mirror in 160 mm diameter for correction polishing. The final result of the In this study, efficient polishing processes with inspection procedures for a large convex hyperbolic mirror of Cassegrain optical system are presented. The polishing process combines the techniques of conventional lapping and CNC polishing. We apply the conventional spherical lapping process to quickly remove the sub-surface damage (SSD) layer caused by grinding process and to get the accurate radius of best-fit sphere (BFS) of aspheric surface with fine surface texture simultaneously. Thus the removed material for aspherization process can be minimized and the polishing time for SSD removal can also be reduced substantially. The inspection procedure was carried out by using phase shift interferometer with CGH and stitching technique. To acquire the real surface form error of each sub aperture, the wavefront errors of the reference flat and CGH flat due to gravity effect of the vertical setup are calibrated in advance. Subsequently, we stitch 10 calibrated sub-aperture surface form errors to establish the whole irregularity of the mirror in 160 mm diameter for correction polishing. The final result of the Fabrication of ф160 mm Convex Hyperbolic Mirror for Remote Sensing Instrument160 mm convex hyperbolic mirror is 0.15 μm PV and 17.9 nm RMS.160 mm convex hyperbolic mirror is 0.15 μm PV and 17.9 nm RMS.

Evaluation of hydrogen isotope exchange methodology on adsorbents for tritium removal

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

Morgan, G.A.; Xin Xiao, S.

2015-03-15

The Savannah River National Laboratory has demonstrated a potential process that can be used to remove tritium from tritiated water using Pt-catalyzed molecular sieves. The process is an elemental isotope exchange process in which H{sub 2} (when flowed through the molecular sieves) will exchange with the adsorbed water, D{sub 2}O, leaving H{sub 2}O adsorbed on the molecular sieves. Various formulations of catalyzed molecular sieve material were prepared using two different techniques, Pt-implantation and Pt-ion exchange. This technology has been demonstrated for a protium (H) and deuterium (D) system, but can also be used for the removal of tritium from contaminatedmore » water (T{sub 2}O, HTO, and DTO) using D{sub 2} (or H{sub 2}). (authors)« less

Regenerative process and system for the simultaneous removal of particulates and the oxides of sulfur and nitrogen from a gas stream

DOEpatents

Cohen, M.R.; Gal, E.

1993-04-13

A process and system are described for simultaneously removing from a gaseous mixture, sulfur oxides by means of a solid sulfur oxide acceptor on a porous carrier, nitrogen oxides by means of ammonia gas and particulate matter by means of filtration and for the regeneration of loaded solid sulfur oxide acceptor. Finely-divided solid sulfur oxide acceptor is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally pre-filtered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor is injected into the gaseous mixture.

Reduction and removal of Cr(VI) from aqueous solutions using modified byproducts of beer production.

PubMed

Cui, Haojie; Fu, Minglai; Yu, Shen; Wang, Ming Kuang

2011-02-28

Biosorption, as an effective and low-cost technology treating industrial wastewaters containing Cr(VI), has become a significant concern worldwide. In this work, acid-modified byproducts of beer production (BBP) were used to remove Cr(VI) from aqueous solutions. Removal of Cr(VI) increases as the pH is decreased from 4.0 to 1.5, but the maximum of total Cr removal is obtained in a pH range from 2.0 to 2.5. Nearly 60% of the initial Cr(VI) (100 mg L(-1)) was adsorbed or reduced to Cr(III) within the first 10 min at pH 2.0. The Cr(VI) removal capability of acid-modified BBP materials was almost completely retained after regenerating with acid. FT-IR and XPS spectra revealed that carboxylate and carboxyl groups on the surface of modified BBP materials play a major role in Cr(VI) binding and reduction, whereas amide and other groups play a minor role in the Cr(VI) removal process. Copyright © 2010 Elsevier B.V. All rights reserved.

Conformally encapsulated multi-electrode arrays with seamless insulation

DOEpatents

Tabada, Phillipe J.; Shah, Kedar G.; Tolosa, Vanessa; Pannu, Satinderall S.; Tooker, Angela; Delima, Terri; Sheth, Heeral; Felix, Sarah

2016-11-22

Thin-film multi-electrode arrays (MEA) having one or more electrically conductive beams conformally encapsulated in a seamless block of electrically insulating material, and methods of fabricating such MEAs using reproducible, microfabrication processes. One or more electrically conductive traces are formed on scaffold material that is subsequently removed to suspend the traces over a substrate by support portions of the trace beam in contact with the substrate. By encapsulating the suspended traces, either individually or together, with a single continuous layer of an electrically insulating material, a seamless block of electrically insulating material is formed that conforms to the shape of the trace beam structure, including any trace backings which provide suspension support. Electrical contacts, electrodes, or leads of the traces are exposed from the encapsulated trace beam structure by removing the substrate.

Mesoporous aluminosilicate glasses: Potential materials for dye removal from wastewater effluents

NASA Astrophysics Data System (ADS)

Almeida, Flavio P.; Botelho, Moema B. S.; Doerenkamp, Carsten; Kessler, Elizaveta; Ferrari, Cynthia R.; Eckert, Hellmut; de Camargo, Andrea S. S.

2017-09-01

Mesoporous amorphous sodium-aluminosilicate host matrices of composition Si1-xAlxNaxO2, 0.1 ≤ x ≤ 0.33, obtained by sol-gel methodology, have been used as sequestrating agents for the cationic dye Rhodamine 6 G (Rh6G) in solution. Favorable adsorption kinetics and a wide pH working range (4-10) as well as high sorption capacities for Rh6G render these materials potentially useful reagents for effective dye removal from wastewaters. While the experimentally realized sorption capacities fall significantly below the theoretical limits, used materials can be thermally re-cycled by pyrolizing the sequestrated dye molecules. Solid state NMR and BET measurements show that this process occurs under preservation of the materials' structural integrity, allowing it to be re-used multiple times.

Feasibility studies for the treatment and reuse of contaminated marine sediments.

PubMed

Bonomoa, L; Careghini, A; Dastoli, S; De Propris, L; Ferrari, G; Gabellini, M; Saponaro, S

2009-07-01

This paper presents preliminary results of laboratory tests aimed at evaluating the easibility of the remediation of marine sediments, which are polluted by mercury and petroleum hydrocarbons, dredged at the bay of Augusta (SR, Italy). The treatment is composed of two sequential steps: in the first, a cement-based granular material is produced (based on a high performance concrete approach); then, the volatile and the semi-volatile compounds in the granular material are removed by a thermal desorption step. Treated materials could be reused or put into caissons, according to their mechanical properties and environmental compatibility. The experiments were focused on evaluating the effect of the process parameter values on: (i) the evolution of cement hydration reactions, (ii) thermal desorption removal efficiencies, (iii) leaching behaviour of the treated material.

Comparison of low-cost and engineered materials for phosphorus removal from organic-rich surface water.

PubMed

Boyer, Treavor H; Persaud, Amar; Banerjee, Poulomi; Palomino, Pedro

2011-10-15

Excess phosphorus (P) in lakes and rivers remains a major water quality problem on a global scale. As a result, new materials and innovative approaches to P remediation are required. Natural materials and waste byproduct materials from industrial processes have the potential to be effective materials for P removal from surface water. Advantages of natural and waste byproduct materials include their low-cost, abundant supply, and minimal preparation, especially compared with engineered materials, such as ion exchange resins and polymeric adsorbents. As a result, natural and waste byproduct materials are commonly referred to as low-cost materials. Despite the potential advantages of low-cost materials, there are critical gaps in knowledge that are preventing their effective use. In particular, there are limited data on the performance of low-cost materials in surface waters that have high concentrations of natural organic matter (NOM), and there are no systematic studies that track the changes in water chemistry following treatment with low-cost materials or compare their performance with engineered materials. Accordingly, the goal of this work was to evaluate and compare the effectiveness of low-cost and engineered materials for P removal from NOM-rich surface water. Seven low-cost materials and three engineered materials were evaluated using jar tests and mini-column experiments. The test water was a surface water that had a total P concentration of 132-250 μg P/L and a total organic carbon concentration of 15-32 mg C/L. Alum sludge, a byproduct of drinking water treatment, and a hybrid anion exchange resin loaded with nanosize iron oxide were the best performing materials in terms of selective P removal in the presence of NOM and minimum undesirable secondary changes to the water chemistry. Copyright © 2011 Elsevier Ltd. All rights reserved.

Methylene blue adsorption by algal biomass based materials: biosorbents characterization and process behaviour.

PubMed

Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

2007-08-17

Dead algal biomass is a natural material that serves as a basis for developing a new family of sorbent materials potentially suitable for many industrial applications. In this work an algal industrial waste from agar extraction process, algae Gelidium and a composite material obtained by immobilization of the algal waste with polyacrylonitrile (PAN) were physical characterized and used as biosorbents for dyes removal using methylene blue as model. The apparent and real densities and the porosity of biosorbents particles were determined by mercury porosimetry and helium picnometry. The methylene blue adsorption in the liquid phase was the method chosen to calculate the specific surface area of biosorbent particles as it seems to reproduce better the surface area accessible to metal ions in the biosorption process than the N2 adsorption-desorption dry method. The porous texture of the biosorbents particles was also studied. Equilibrium isotherms are well described by the Langmuir equation, giving maximum uptake capacities of 171, 104 and 74 mg g(-1), respectively for algae, algal waste and composite material. Kinetic experiments at different initial methylene blue concentrations were performed to evaluate the equilibrium time and the importance of the driving force to overcome mass transfer resistances. The pseudo-first-order and pseudo-second-order kinetic models adequately describe the kinetic data. The biosorbents used in this work proved to be promising materials for removing methylene blue from aqueous solutions.

Method for the preparation of ferrous low carbon porous material

DOEpatents

Miller, Curtis Jack

2014-05-27

A method for preparing a porous metal article using a powder metallurgy forming process is provided which eliminates the conventional steps associated with removing residual carbon. The method uses a feedstock that includes a ferrous metal powder and a polycarbonate binder. The polycarbonate binder can be removed by thermal decomposition after the metal article is formed without leaving a carbon residue.

Quantification of the amount of dental material removed by selective grinding in wax dentures with photogrammetric measurements.

PubMed

Ravasini, Francesco; Fornari, Matteo; Bonanini, Mauro

2016-12-01

The use of photogrammetry may be a new method to quantify the amount of artificial dental material removed from the surface of each teeth during the grind procedure (SG). SG is necessary in each denture to reach a correct occlusion. It consists in a refine action on the prosthesis teeth's surface using milling machine tools, aimed to remove the interferences (pre-contacts) between upper and lower teeth during chewing. This measure is achieved after a comparison between pre and post-grinding 3D models. This new application could be of interest for both dentists and dental technicians because it could be used to evaluate, with a accurate numerical description, the action applied on teeth surfaces during the grinding process. Furthermore, results of the analysis could have some value for the dental industry, since the use of photogrammetry can improve the process, reducing costs during the design of artificial teeth and eventually this method could be used as a teaching tool both for dental and "dental technician" high school students. The purpose of this work is to measure the thickness of the artificial enamel removed during grinding phases. Usually, the dental technician adjusts the dental plate on the mount of the patient following the traditional method, without a quantitative evaluation of the material removed. The photogrammetric method (PM) proposed here allows to measure the amount of material removed during the grinding process. This measure is achieved after a comparison between pre and post-grinding 3D models. Under control of three teachers (experts of dentures performed according to the Gerber method) ten complete dentures arrangements (upper and inferior arches) performed by dental students at the Prosthodontic Department of the University of Parma, Italy were analyzed with PM before and after SG. The average thickness variation between the pre and post-grinding dentures is within the range of 0.1÷0.4 mm. For the upper arches, the mean value of the SG process is 223 µm while for the inferior arches is 240 µm. Results show that the most important grind process in all models appear in correspondence of cusps, with values up to 1660 µm. On the other hand, in correspondence of the fossae the results show a moderate grind action: the value is around 200-300 µm. Conversely to guidelines thought to students: cusps undergo a greater grinding process than fossae, consequently cusps should be revisioned at least on their technical and morphological aspects. The average thickness variation between the pre and post-grinding dentures is within the range of 0.1÷0.4 mm, this mean an equal value loss of vertical dimension. Furthermore, the knowledge of the gauge material removed during the SG could be useful for dental industries, giving important information, that could be considered for project and design of artificial teeth. The FM implemented in this article has given satisfactory preliminary results, showing good accuracy, low costs and high versatility. It is necessary to highlight that this is an experimental method and that the present analysis is a pilot study that needs further evaluation. Nevertheless results obtained could be of some value for medical companies, in order to improve the artificial teeth's design and project. Moreover, such a method may serve as educational tool for dental students.

40 CFR 63.7882 - What site remediation sources at my facility does this subpart affect?

Code of Federal Regulations, 2014 CFR

2014-07-01

... source is the entire group of process vents associated with the in-situ and ex-situ remediation processes used at your site to remove, destroy, degrade, transform, or immobilize hazardous substances in the remediation material subject to remediation. Examples of such in-situ remediation processes include, but are...

40 CFR 63.7882 - What site remediation sources at my facility does this subpart affect?

Code of Federal Regulations, 2013 CFR

2013-07-01

... source is the entire group of process vents associated with the in-situ and ex-situ remediation processes used at your site to remove, destroy, degrade, transform, or immobilize hazardous substances in the remediation material subject to remediation. Examples of such in-situ remediation processes include, but are...

40 CFR 63.7882 - What site remediation sources at my facility does this subpart affect?

Code of Federal Regulations, 2011 CFR

2011-07-01

... source is the entire group of process vents associated with the in-situ and ex-situ remediation processes used at your site to remove, destroy, degrade, transform, or immobilize hazardous substances in the remediation material subject to remediation. Examples of such in-situ remediation processes include, but are...

40 CFR 63.7882 - What site remediation sources at my facility does this subpart affect?

Code of Federal Regulations, 2012 CFR

2012-07-01

... source is the entire group of process vents associated with the in-situ and ex-situ remediation processes used at your site to remove, destroy, degrade, transform, or immobilize hazardous substances in the remediation material subject to remediation. Examples of such in-situ remediation processes include, but are...

Irradiated foods

MedlinePlus

... materials that kill bacteria. The process is called irradiation. It is used to remove germs from food. ... it reduces the risk for food poisoning . Food irradiation is used in many countries. It was first ...

Process to remove actinides from soil using magnetic separation

DOEpatents

Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

1996-01-01

A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

Cleaning By Blasting With Pellets Of Dry Ice

NASA Technical Reports Server (NTRS)

Fody, Jody

1993-01-01

Dry process strips protective surface coats from parts to be cleaned, without manual scrubbing. Does not involve use of flammable or toxic solvents. Used to remove coats from variety of materials, including plastics, ceramics, ferrous and nonferrous metals, and composites. Adds no chemical-pollution problem to problem of disposal of residue of coating material. Process consists of blasting solid carbon dioxide (dry ice) pellets at surface to be cleaned. Pellets sublime on impact and pass into atmosphere as carbon dioxide gas. Size, harness, velocity, and quantity of pellets adjusted to suit coating material and substrate.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

PubMed

Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

H-Coal process and plant design

DOEpatents

Kydd, Paul H.; Chervenak, Michael C.; DeVaux, George R.

1983-01-01

A process for converting coal and other hydrocarbonaceous materials into useful and more valuable liquid products. The process comprises: feeding coal and/or other hydrocarbonaceous materials with a hydrogen-containing gas into an ebullated catalyst bed reactor; passing the reaction products from the reactor to a hot separator where the vaporous and distillate products are separated from the residuals; introducing the vaporous and distillate products from the separator directly into a hydrotreater where they are further hydrogenated; passing the residuals from the separator successively through flash vessels at reduced pressures where distillates are flashed off and combined with the vaporous and distillate products to be hydrogenated; transferring the unseparated residuals to a solids concentrating and removal means to remove a substantial portion of solids therefrom and recycling the remaining residual oil to the reactor; and passing the hydrogenated vaporous and distillate products to an atmospheric fractionator where the combined products are fractionated into separate valuable liquid products. The hydrogen-containing gas is generated from sources within the process.

Algorithm for ion beam figuring of low-gradient mirrors.

PubMed

Jiao, Changjun; Li, Shengyi; Xie, Xuhui

2009-07-20

Ion beam figuring technology for low-gradient mirrors is discussed. Ion beam figuring is a noncontact machining technique in which a beam of high-energy ions is directed toward a target workpiece to remove material in a predetermined and controlled fashion. Owing to this noncontact mode of material removal, problems associated with tool wear and edge effects, which are common in conventional contact polishing processes, are avoided. Based on the Bayesian principle, an iterative dwell time algorithm for planar mirrors is deduced from the computer-controlled optical surfacing (CCOS) principle. With the properties of the removal function, the shaping process of low-gradient mirrors can be approximated by the linear model for planar mirrors. With these discussions, the error surface figuring technology for low-gradient mirrors with a linear path is set up. With the near-Gaussian property of the removal function, the figuring process with a spiral path can be described by the conventional linear CCOS principle, and a Bayesian-based iterative algorithm can be used to deconvolute the dwell time. Moreover, the selection criterion of the spiral parameter is given. Ion beam figuring technology with a spiral scan path based on these methods can be used to figure mirrors with non-axis-symmetrical errors. Experiments on SiC chemical vapor deposition planar and Zerodur paraboloid samples are made, and the final surface errors are all below 1/100 lambda.

Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

NASA Technical Reports Server (NTRS)

Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

1975-01-01

Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

Application of vascular aquatic plants for pollution removal, energy, and food production in a biological system

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

Wolverton, B.C.; Barlow, R.M.; Mcdonald, R.C.

1975-05-12

Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications. (Author) (GRA)

A comparative evaluation of IONSIV{reg_sign} IE-911 and chabazite zeolite for the removal of radiostrontium and cesium from wastewater

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

Bostick, D.T.; DePaoli, S.M.; Guo, B.

1998-11-01

Natural chabazite zeolite was selected as the baseline treatment technology for the removal of fission products, namely {sup 90}Sr and {sup 137}Cs, from near-neutral-pH process wastewater and groundwater. The sorbent IONSIV{reg_sign} IE-911, a crystalline silicotitanate manufactured by UOP, was recently tested in this capacity and found to compare extremely well against the baseline material. This paper presents and compares the results of similar batch and column tests performed using both materials, and summarizes the physical and chemical characteristics of the sorbents.

In Situ NDA Conformation Measurements Performed at Auxiliary Charcoal Bed and Other Main Charcoal Beds After Uranium Removal from Molten Salt Reactor Experiment ACB at Oak Ridge National Laboratory

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

Haghighi, M. H.; Kring, C. T.; McGehee, J. T.

2002-02-26

The Molten Salt Reactor Experiment (MSRE) site is located in Tennessee, on the U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR). The MSRE was run by Oak Ridge National Laboratory (ORNL) to demonstrate the desirable features of the molten-salt concept in a practical reactor that could be operated safely and reliably. It introduced the idea of a homogeneous reactor using fuel salt media and graphite moderation for power and breeder reactors. The MSRE reactor and associated components are located in cells beneath the floor in the high-bay area of Building 7503. The reactor was operated from June 1965 tomore » December 1969. When the reactor was shut down, fuel salt was drained from the reactor circuit to two drain tanks. A ''clean'' salt was then circulated through the reactor as a decontamination measure and drained to a third drain tank. When operations ceased, the fuel and flush salts were allowed to cool and solidify in the drain tanks. At shutdown, the MSRE facility complex was placed in a surveillance and maintenance program. Beginning in 1987, it was discovered that gaseous uranium (U-233/U-232) hexafluoride (UF6) had moved throughout the MSRE process systems. The UF6 had been generated when radiolysis in the fluorine salts caused the individual constituents to dissociate to their component atoms, including free fluorine. Some of the free fluorine combined with uranium fluorides (UF4) in the salt to produce UF6. UF6 is gaseous at slightly above ambient temperatures; thus, periodic heating of the fuel salts (which was intended to remedy the radiolysis problems) and simple diffusion had allowed the UF6 to move out of the salt and into the process systems of MSRE. One of the systems that UF6 migrated into due to this process was the offgas system which is vented to the MSRE main charcoal beds and MSRE auxiliary charcoal bed (ACB). Recently, the majority of the uranium laden-charcoal material residing within the ACB was safely and successfully removed using the uranium deposit removal system and equipment. After removal a series of NDA measurements was performed to determine the amount of uranium material remaining in the ACB, the amount of uranium material removed from the ACB, and the amount of uranium material remaining in the uranium removal equipment due to removal activities.« less

Applications of magnetic hybrid adsorbent derived from waste biomass for the removal of metal ions and reduction of 4-nitrophenol.

PubMed

Cunha, Graziele da C; Dos Santos, Bruna Thaysa; Alves, Jôse Raymara; Alves Silva, Iris Amanda; de Souza Cruz, Daiane Requião; Romão, Luciane P C

2018-05-01

The use of industrial waste to synthesize materials of technological interest is a rational way to minimize or solve environmental pollution problems. This work investigates the adsorption of cadmium and lead ions by magnetic hybrid adsorbents synthesized using the in natura biomasses coconut mesocarp (CCFe), sawdust (SAFe), and termite nest (TEFe) for the organic phases and magnetic cobalt ferrite as the inorganic phase. The formation of a cobalt ferrite phase was confirmed by XRD. The use of XRD and FTIR analyses revealed the presence of organic matter in the structure of the material. Removal assays performed at different pH values (2.0-8.0) showed the effectiveness of the adsorbent for the removal of Pb 2+ at pH 3.0 and Cd 2+ at pH 4.0. The adsorption processes showed fast kinetics, with removal of 79-86% of Pb 2+ and 49% of Cd 2+ within only 5 min, and removal of 92-96% of the metal species at equilibrium. In the case of cadmium, the hybrid sorbents (CCFe, SAFe, and TEFe) showed high removal capacity after three reuse cycles, while the removal of lead decreased from 99% to 40%. The adsorbent matrices saturated with the recovered cadmium and lead ions showed excellent catalytic performance in the reduction of 4-nitrophenol, with 99.9% conversion within 43-56 s. The materials showed high capacities for reuse in three successive reduction cycles. The findings highlight the effectiveness of an industrial symbiosis approach to the development of new technologically important materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Investigate the complex process in particle-fluid based surface generation technology using reactive molecular dynamics method

NASA Astrophysics Data System (ADS)

Han, Xuesong; Li, Haiyan; Zhao, Fu

2017-07-01

Particle-fluid based surface generation process has already become one of the most important materials processing technology for many advanced materials such as optical crystal, ceramics and so on. Most of the particle-fluid based surface generation technology involves two key process: chemical reaction which is responsible for surface softening; physical behavior which is responsible for materials removal/deformation. Presently, researchers cannot give a reasonable explanation about the complex process in the particle-fluid based surface generation technology because of the small temporal-spatial scale and the concurrent influence of physical-chemical process. Molecular dynamics (MD) method has already been proved to be a promising approach for constructing effective model of atomic scale phenomenon and can serve as a predicting simulation tool in analyzing the complex surface generation mechanism and is employed in this research to study the essence of surface generation. The deformation and piles of water molecule is induced with the feeding of abrasive particle which justifies the property mutation of water at nanometer scale. There are little silica molecule aggregation or materials removal because the water-layer greatly reduce the strength of mechanical interaction between particle and materials surface and minimize the stress concentration. Furthermore, chemical effect is also observed at the interface: stable chemical bond is generated between water and silica which lead to the formation of silconl and the reaction rate changes with the amount of water molecules in the local environment. Novel ring structure is observed in the silica surface and it is justified to be favored of chemical reaction with water molecule. The siloxane bond formation process quickly strengthened across the interface with the feeding of abrasive particle because of the compressive stress resulted by the impacting behavior.

The effect of materials selection on metals reduction in propylene glycol methyl ether acetate, PGMEA

NASA Astrophysics Data System (ADS)

Entezarian, Majid; Geiger, Bob

2016-03-01

The trend in microelectronics fabrication is to produce nano-features measuring down to 10 nm and finer. The PPT levels of organic and inorganic contaminants in the photoresist, solvent and cleaning solutions are becoming a major processing variable affecting the process capability and defectivity. The photoresist usually contains gels, metals, and particulates that could interfere with the lithography process and cause microbridging defects. Nano filters of 5 nm polypropylene, 5 nm polyethylene, and 10 nm natural nylon were used to filter propylene glycol methyl ether acetate PGMEA containing 50 ppb of Na, Mg, Al, Ca, Cr, Mn, Fe, Cu, Zn, and Pb. All filters were effective in removing trivalent Al, Cr, and Fe metals indicating the mechanism for their removal as mechanical sieving. However, the nylon was also very effective in removing the divalent metals showing adsorptive properties. Furthermore, the metal removal of the nylon membrane was studied as a function of surface chemistry. Natural and charged 40 nm nylon membranes were tested and found that charged nylon is more effective for metal removal.

Aerospace Environmental Technology Conference: Exectutive summary

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor)

1995-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The papers from this conference are being published in a separate volume as NASA CP-3298.

Chemical mechanisms of photocatalytic de-soiling and de-polluting processes in indoor environments and urban surfaces

NASA Astrophysics Data System (ADS)

Sleiman, M.; Rosseler, O.; Montesinos, N.; Litter, M.; Bikiel, D.; Kirchstetter, T.; Bluhm, H.; Ahmed, M.; Salmeron, M.; Destaillats, H.

2013-12-01

Photocatalysis has been postulated as a promising approach for the de-pollution of indoor air and urban atmospheres, and for self-cleaning surfaces. Building materials and coatings containing nano-sized TiO2 photocatalytic functionalities are gaining market share, including self-cleaning building envelope materials (coatings, mortar, plaster, architectural fabrics and tiles) and indoor air purifiers. While many studies have reported good performance of photocatalysis in the removal of organic pollutants from indoor air, more information is needed to understand secondary emissions of potentially harmful byproducts from photocatalytic air cleaners. This presentation will describe analytical methods and experimental results from room-sized chamber experiments using a realistic challenge VOC mixture at low ppb levels. We will also present results from separate studies that used synchrotron-based surface spectroscopic and mass spectrometric methods to better understand the photocatalytic mechanisms that regulate the de-soiling and de-polluting activity. Two photocatalytic processes were studied: de-noxification (NOx removal) and de-soiling (removal of deposited black carbon or soot). Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at λ = 365 nm. The results illustrate how NOx chemistry on TiO2 surfaces can be affected by the presence of water vapor, heteroatoms present as impurities, and carbonaceous soiling. The reactivity of NOx and NO3- on surfaces leads to reduced adsorbed and gas-phase nitrogenated species. These processes need to be considered in the engineering of depolluting materials and incorporated into atmospheric models. De-soiling properties were investigated by analyzing soot oxidation on TiO2 surfaces. Model soot samples were used as surrogates of urban grime. Using laser desorption coupled with time-of-flight (TOF) mass spectrometry synchrotron ionization, we investigated the mechanisms of photocatalytic soot removal under UVA irradiation. Ancillary reflectance measurements were performed to determine the efficiency and kinetics of soot removal.

Carbon dioxide capture from power or process plant gases

DOEpatents

Bearden, Mark D; Humble, Paul H

2014-06-10

The present invention are methods for removing preselected substances from a mixed flue gas stream characterized by cooling said mixed flue gas by direct contact with a quench liquid to condense at least one preselected substance and form a cooled flue gas without substantial ice formation on a heat exchanger. After cooling additional process methods utilizing a cryogenic approach and physical concentration and separation or pressurization and sorbent capture may be utilized to selectively remove these materials from the mixed flue gas resulting in a clean flue gas.

K basins sludge removal sludge pretreatment system

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

Chang, H.L.

1997-06-12

The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task formore » this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.« less

Treatment of wastewater from a cotton dyeing process with UV/H2O2 using a photoreactor covered with reflective material.

PubMed

de Melo, Claudinei Fernandes; da Silva, Flavio T; de Paiva, Teresa C B

2011-01-01

Wastewater containing several dyes, including sulfur black from the dyeing process in a textile mill, was treated using a UV/H2O2 process. The wastewater was characterized by a low BOD/COD ratio, intense color and high acute toxicity to the algae species Pseudokirchneriella subcaptata. The influence of the pH and H2O2 concentration on the treatment process was evaluated by a full factorial design 22 with three replicates of the central experiment. The removal of aromatic compounds and color was improved by an increase in the H2O2 concentration and a decrease in pH. The best results were obtained at pH 5.0 and 6 g L(-1). With these conditions and 120 min of UV irradiation, the removal of the color, aromatic compounds and COD were 74.1, 55.1 and 44.8%, respectively. Under the same conditions, but using a photoreactor covered with aluminum foil, the removal of the color, aromatic compounds and COD were 92.0, 77.6 and 59.4%, respectively. Moreover, the use of aluminum foil reduced the cost of the treatment by 40.8%. These results suggest the potential application of reflective materials as a photoreactor accessory to reduce electric energy consumption during the UV/H2O2 process.

Process Design and Techno-economic Analysis for Materials to Treat Produced Waters.

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

Heimer, Brandon Walter; Paap, Scott M; Sasan, Koroush

Significant quantities of water are produced during enhanced oil recovery making these “produced water” streams attractive candidates for treatment and reuse. However, high concentrations of dissolved silica raise the propensity for fouling. In this paper, we report the design and economic analysis for a new ion exchange process using calcined hydrotalcite (HTC) to remove silica from water. This process improves upon known technologies by minimizing sludge product, reducing process fouling, and lowering energy use. Process modeling outputs included raw material requirements, energy use, and the minimum water treatment price (MWTP). Monte Carlo simulations quantified the impact of uncertainty and variabilitymore » in process inputs on MWTP. These analyses showed that cost can be significantly reduced if the HTC materials are optimized. Specifically, R&D improving HTC reusability, silica binding capacity, and raw material price can reduce MWTP by 40%, 13%, and 20%, respectively. Optimizing geographic deployment further improves cost competitiveness.« less

Sequential electrokinetic treatment and oxalic acid extraction for the removal of Cu, Cr and As from wood.

PubMed

Isosaari, Pirjo; Marjavaara, Pieti; Lehmus, Eila

2010-10-15

Removal of Cu, Cr and As from utility poles treated with chromated copper arsenate (CCA) was investigated using different one- to three-step combinations of oxalic acid extraction and electrokinetic treatment. The experiments were carried out at room temperature, using 0.8% oxalic acid and 30 V (200 V/m) of direct current (DC) or alternating current in combination (DC/AC). Six-hour extraction removed only 15%, 11% and 28% and 7-day electrokinetic treatment 57%, 0% and 17% of Cu, Cr and As from wood chips, respectively. The best combination for all the metals was a three-step process consisting of pre-extraction, electrokinetics and post-extraction steps, yielding removals of 67% for Cu, 64% for Cr and 81% for As. Oxalic acid extraction prior to electrokinetic treatment was deleterious to further removal of Cu, but it was necessary for Cr and As removal. Chemical equilibrium modelling was used to explain the differences in the behaviour of Cu, Cr and As. Due to the dissimilar nature of these metals, it appeared that even more process sequences and/or stricter control of the process conditions would be needed to obtain the >99% removals required for safe recycling of the purified wood material. 2010 Elsevier B.V. All rights reserved.

Advanced CO2 Removal Technology Development

NASA Technical Reports Server (NTRS)

Finn, John E.; Verma, Sunita; Forrest, Kindall; LeVan, M. Douglas

2001-01-01

The Advanced CO2 Removal Technical Task Agreement covers three active areas of research and development. These include a study of the economic viability of a hybrid membrane/adsorption CO2 removal system, sorbent materials development, and construction of a database of adsorption properties of important fixed gases on several adsorbent material that may be used in CO2 removal systems. The membrane/adsorption CO2 removal system was proposed as a possible way to reduce the energy consumption of the four-bed molecular sieve system now in use. Much of the energy used by the 4BMS is used to desorb water removed in the device s desiccant beds. These beds might be replaced by a desiccating membrane that moves the water from [he incoming stream directly into the outlet stream. The approach may allow the CO2 removal beds to operate at a lower temperature. A comparison between models of the 4BMS and hybrid systems is underway at Vanderbilt University. NASA Ames Research Center has been investigating a Ag-exchanged zeolites as a possible improvement over currently used Ca and Na zeolites for CO2 removal. Silver ions will complex with n:-bonds in hydrocarbons such as ethylene, giving remarkably improved selectivity for adsorption of those materials. Bonds with n: character are also present in carbon oxides. NASA Ames is also continuing to build a database for adsorption isotherms of CO2, N2, O2, CH4, and Ar on a variety of sorbents. This information is useful for analysis of existing hardware and design of new processes.

A Guide for Developing Standard Operating Job Procedures for the Screening & Grinding Process Wastewater Treatment Facility. SOJP No. 1.

ERIC Educational Resources Information Center

Deal, Gerald A.; Montgomery, James A.

This guide describes standard operating job procedures for the screening and grinding process of wastewater treatment facilities. The objective of this process is the removal of coarse materials from the raw waste stream for the protection of subsequent equipment and processes. The guide gives step-by-step instructions for safety inspection,…

A Guide for Developing Standard Operating Job Procedures for the Sludge Thickening Process Wastewater Treatment Facility. SOJP No. 9.

ERIC Educational Resources Information Center

Schwing, Carl M.

This guide describes standard operating job procedures for the screening and grinding process of wastewater treatment facilities. The objective of this process is the removal of coarse materials from the raw waste stream for the protection of subsequent equipment and processes. The guide gives step-by-step instructions for safety inspection,…

Removal of Water-Soluble Extractives Improves the Enzymatic Digestibility of Steam-Pretreated Softwood Barks.

PubMed

Frankó, Balázs; Carlqvist, Karin; Galbe, Mats; Lidén, Gunnar; Wallberg, Ola

2018-02-01

Softwood bark contains a large amounts of extractives-i.e., soluble lipophilic (such as resin acids) and hydrophilic components (phenolic compounds, stilbenes). The effects of the partial removal of water-soluble extractives before acid-catalyzed steam pretreatment on enzymatic digestibility were assessed for two softwood barks-Norway spruce and Scots pine. A simple hot water extraction step removed more than half of the water-soluble extractives from the barks, which improved the enzymatic digestibility of both steam-pretreated materials. This effect was more pronounced for the spruce than the pine bark, as evidenced by the 30 and 11% glucose yield improvement, respectively, in the enzymatic digestibility. Furthermore, analysis of the chemical composition showed that the acid-insoluble lignin content of the pretreated materials decreased when water-soluble extractives were removed prior to steam pretreatment. This can be explained by a decreased formation of water-insoluble "pseudo-lignin" from water-soluble bark phenolics during the acid-catalyzed pretreatment, which otherwise results in distorted lignin analysis and may also contribute to the impaired enzymatic digestibility of the barks. Thus, this study advocates the removal of extractives as the first step in the processing of bark or bark-rich materials in a sugar platform biorefinery.

Preparation of fly ash based zeolite for removal of fluoride from drinking water

NASA Astrophysics Data System (ADS)

Panda, Laxmidhar; Kar, Biswabandita; Dash, Subhakanta

2018-05-01

Fluoride contamination of drinking water is a worldwide phenomenon and scientists are working relentlessly to find ways to remove fluoride from drinking water. Out of the different methods employed for removal fluoride from drinking water adsorption process is the most suitable because in this process the adsorbent is regenerated and the process is cost effective. In the present study fly ash is used as the raw material, which is treated with alkali (NaOH) to form NaP1 zeolite. This zeolite is then subjected to characterization by standard procedures. It is found that the synthesized zeolite has more crystalline character than the raw fly ash and has also more voids and channels on its surface. The surface of the synthesized zeolite is modified with calcium chloride and the same is employed for removal of fluoride under varying pH, contact time, initial concentration of fluoride, temperature and adsorbent dose etc so as to assess the suitably or otherwise of the synthesized product.

Multiwall carbon nanotube embedded phenolic resin-based carbon foam for the removal of As (V) from contaminated water

NASA Astrophysics Data System (ADS)

Rani Agrawal, Pinki; Singh, Nahar; Kumari, Saroj; Dhakate, Sanjay R.

2018-03-01

It is well proposed that micron or nano size filters requires to separate adsorbent from water after removal of adsorbate. However, even after filtration trace quantity of adsorbent remains in purified water, which deteriorates the quality of water for potability. To overcome these problems, multi walled carbon nanotube (MWCNT) loaded Carbon Foam (CF) was fabricated by a sacrificial template process. In this process, multi walled carbon nanotubes (MWCNTs) and phenolic resin mixture was used for the impregnation of the polyurethane (PU) template. Impregnated PU Foam stabilized and carbonized to get MWCNTs embedded Carbon Foam (CF). The MWCNT loaded CF (MWCNTs-CF) was used for the removal of As (V) species from water. The proposed foam efficiently removes arsenic (As (V)) from water and it can be easily separated from water after purification without any sophisticated tools. The adsorption capacity of the proposed material was found to be 90.5 μg*g-1 at optimized condition of pH, time and concentration, which is excellent in comparison to several other materials utilized for removal of As (V). Kinetic and isotherm studies reveal that the multilayer adsorption over heterogeneous surface follows pseudo second order kinetics. The adsorption phenomena were further confirmed by several characterization techniques like scanning electron microscope (SEM), x-ray diffraction (XRD) spectroscopy and x-ray photoelectron spectroscopy (XPS).

Material condition assessment with eddy current sensors

NASA Technical Reports Server (NTRS)

Goldfine, Neil J. (Inventor); Washabaugh, Andrew P. (Inventor); Sheiretov, Yanko K. (Inventor); Schlicker, Darrell E. (Inventor); Lyons, Robert J. (Inventor); Windoloski, Mark D. (Inventor); Craven, Christopher A. (Inventor); Tsukernik, Vladimir B. (Inventor); Grundy, David C. (Inventor)

2010-01-01

Eddy current sensors and sensor arrays are used for process quality and material condition assessment of conducting materials. In an embodiment, changes in spatially registered high resolution images taken before and after cold work processing reflect the quality of the process, such as intensity and coverage. These images also permit the suppression or removal of local outlier variations. Anisotropy in a material property, such as magnetic permeability or electrical conductivity, can be intentionally introduced and used to assess material condition resulting from an operation, such as a cold work or heat treatment. The anisotropy is determined by sensors that provide directional property measurements. The sensor directionality arises from constructs that use a linear conducting drive segment to impose the magnetic field in a test material. Maintaining the orientation of this drive segment, and associated sense elements, relative to a material edge provides enhanced sensitivity for crack detection at edges.

Grinding, Machining Morphological Studies on C/SiC Composites

NASA Astrophysics Data System (ADS)

Xiao, Chun-fang; Han, Bing

2018-05-01

C/SiC composite is a typical material difficult to machine. It is hard and brittle. In machining, the cutting force is large, the material removal rate is low, the edge is prone to collapse, and the tool wear is serious. In this paper, the grinding of C/Si composites material along the direction of fiber distribution is studied respectively. The surface microstructure and mechanical properties of C/SiC composites processed by ultrasonic machining were evaluated. The change of surface quality with the change of processing parameters has also been studied. By comparing the performances of conventional grinding and ultrasonic grinding, the surface roughness and functional characteristics of the material can be improved by optimizing the processing parameters.

Potential Alternatives Report for Validation of Alternative Low-Emission Surface PreparationlDepainting Technologies for Structural Steel

NASA Technical Reports Server (NTRS)

Lewis, Pattie

2006-01-01

For this project, particulates and solvents used during the depainting process of steel structures were the identified hazardous material (HazMat) targeted for elimination or reduction. This Potential Alternatives Report (PAR) provides technical analyses of identified alternatives to the current coating removal processes, criteria used to select alternatives for further analysis, and a list of those alternatives recommended for testing. The initial coating removal alternatives list was compiled using literature searches and center participant recommendations. The involved project participants initially considered fifteen (15) alternatives. In late 2004, stakeholders down-selected the list and identified specific processes as potential alternatives to the current depainting methods. The selected alternatives were: 1. Plastic Blast Media 2. Hard Abrasive Media 3. Sponge Blast Media 4. Mechanical Removal with Vacuum Attachment 5. Liquid Nitrogen 6. Laser Coating Removal Available information about these processes was used to analyze the technical merits and the potential environmental, safety, and occupational health (ESOH) impacts of these methods. A preliminary cost benefit analysis will be performed to determine if implementation of alternative technologies is economically justified. NASA AP2

Commercial Production of Heavy Metal Fluoride Glass Fiber in Space

NASA Technical Reports Server (NTRS)

Tucker, Dennis S.; Workman, Gary L.; Smith, Guy A.

1998-01-01

International Space Station Alpha (ISSA) will provide a platform not only for materials research but also a possible means to produce products in space which cannot be easily produced on the ground. Some products may even be superior to those now produced in unit gravity due to the lack of gravity induced convection effects. Our research with ZrF4-BaF2-LaF3-AlF3-NaF (ZBLAN glass) has shown that gravity does indeed play a major role in the crystallization behavior of this material. At the present time ZBLAN is being produced on earth in fiber optic form for use in surgical lasers and fiber optic lasers among other applications. High attenuation coefficients, however, have kept this material from being used in other applications such as long haul data transmission links. The high attenuation coefficients are due to impurities which can be removed through improved processing techniques and crystals which can only be removed or prevented from forming by processing in a reduced gravity environment.

Processes for converting lignocellulosics to reduced acid pyrolysis oil

DOEpatents

Kocal, Joseph Anthony; Brandvold, Timothy A

2015-01-06

Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

Municipal waste processing apparatus

DOEpatents

Mayberry, J.L.

1988-04-13

This invention relates to apparatus for processing municipal waste, and more particularly to vibrating mesh screen conveyor systems for removing grit, glass, and other noncombustible materials from dry municipal waste. Municipal waste must be properly processed and disposed of so that it does not create health risks to the community. Generally, municipal waste, which may be collected in garbage trucks, dumpsters, or the like, is deposited in processing areas such as landfills. Land and environmental controls imposed on landfill operators by governmental bodies have increased in recent years, however, making landfill disposal of solid waste materials more expensive. 6 figs.

Underwater femtosecond laser micromachining of thin nitinol tubes for medical coronary stent manufacture

NASA Astrophysics Data System (ADS)

Muhammad, Noorhafiza; Li, Lin

2012-06-01

Microprofiling of medical coronary stents has been dominated by the use of Nd:YAG lasers with pulse lengths in the range of a few milliseconds, and material removal is based on the melt ejection with a high-pressure gas. As a result, recast and heat-affected zones are produced, and various post-processing procedures are required to remove these defects. This paper reports a new approach of machining stents in submerged conditions using a 100-fs pulsed laser. A comparison is given of dry and underwater femtosecond laser micromachining techniques of nickel-titanium alloy (nitinol) typically used as the material for coronary stents. The characteristics of laser interactions with the material have been studied. A femtosecond Ti:sapphire laser system (wavelength of 800 nm, pulse duration of 100 fs, repetition rate of 1 kHz) was used to perform the cutting process. It is observed that machining under a thin water film resulted in no presence of heat-affected zone, debris, spatter or recast with fine-cut surface quality. At the optimum parameters, the results obtained with dry cutting showed nearly the same cut surface quality as with cutting under water. However, debris and recast formation still appeared on the dry cut, which is based on material vaporization. Physical processes involved during the cutting process in a thin water film, i.e. bubble formation and shock waves, are discussed.

Three-dimensional machining of carbon nanotube forests using water-assisted scanning electron microscope processing

NASA Astrophysics Data System (ADS)

Rajabifar, Bahram; Kim, Sanha; Slinker, Keith; Ehlert, Gregory J.; Hart, A. John; Maschmann, Matthew R.

2015-10-01

We demonstrate that vertically aligned carbon nanotubes (CNTs) can be precisely machined in a low pressure water vapor ambient using the electron beam of an environmental scanning electron microscope. The electron beam locally damages the irradiated regions of the CNT forest and also dissociates the water vapor molecules into reactive species including hydroxyl radicals. These species then locally oxidize the damaged region of the CNTs. The technique offers material removal capabilities ranging from selected CNTs to hundreds of cubic microns. We study how the material removal rate is influenced by the acceleration voltage, beam current, dwell time, operating pressure, and CNT orientation. Milled cuts with depths between 0-100 microns are generated, corresponding to a material removal rate of up to 20.1 μm3/min. The technique produces little carbon residue and does not disturb the native morphology of the CNT network. Finally, we demonstrate direct machining of pyramidal surfaces and re-entrant cuts to create freestanding geometries.

Three-dimensional machining of carbon nanotube forests using water-assisted scanning electron microscope processing

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

Rajabifar, Bahram; Maschmann, Matthew R., E-mail: MaschmannM@missouri.edu; Kim, Sanha

2015-10-05

We demonstrate that vertically aligned carbon nanotubes (CNTs) can be precisely machined in a low pressure water vapor ambient using the electron beam of an environmental scanning electron microscope. The electron beam locally damages the irradiated regions of the CNT forest and also dissociates the water vapor molecules into reactive species including hydroxyl radicals. These species then locally oxidize the damaged region of the CNTs. The technique offers material removal capabilities ranging from selected CNTs to hundreds of cubic microns. We study how the material removal rate is influenced by the acceleration voltage, beam current, dwell time, operating pressure, andmore » CNT orientation. Milled cuts with depths between 0–100 microns are generated, corresponding to a material removal rate of up to 20.1 μm{sup 3}/min. The technique produces little carbon residue and does not disturb the native morphology of the CNT network. Finally, we demonstrate direct machining of pyramidal surfaces and re-entrant cuts to create freestanding geometries.« less

Post-processing, energy production use of sugarcane bagasse ash

USDA-ARS?s Scientific Manuscript database

Sugarcane bagasse ash (SBA) is a multi-process by-product produced from the milling of sugarcane. Bagasse is the fibrous material remaining after removing the sugar, water, and other impurities from the sugarcane delivered to the mill. Louisiana produces an estimated 2.7 mt of bagasse each year. In ...

Post-processing, energy production use of sugarcane bagasse ash

USDA-ARS?s Scientific Manuscript database

Sugarcane bagasse ash (SBA) is a multi-processed by-product produced from the milling of sugarcane. Bagasse is the fibrous material remaining after removing the sugar, water, and other impurities from the sugarcane delivered to the mill. Louisiana produces an estimated 3 million tons of bagasse each...

Research into acetone removal from air by biofiltration using a biofilter with straight structure plates

PubMed Central

Baltrėnas, Pranas; Zagorskis, Alvydas; Misevičius, Antonas

2015-01-01

The biological air treatment method is based on the biological destruction of organic compounds using certain cultures of microorganisms. This method is simple and may be applied in many branches of industry. The main element of biological air treatment devices is a filter charge. Tests were carried out using a new-generation laboratory air purifier with a plate structure. This purifier is called biofilter. The biofilter has a special system for packing material humidification which does not require additional energy inputs. In order to extend the packing material's durability, it was composed of thermally treated birch fibre. Pollutant (acetone) biodegradation occurred on thermally treated wood fibre in this research. According to the performed tests and the received results, the process of biodestruction was highly efficient. When acetone was passed through biofilter's packing material at 0.08 m s−1 rate, the efficiency of the biofiltration process was from 70% up to 90%. The species of bacteria capable of removing acetone vapour from the air, i.e. Bacillus (B. cereus, B. subtilis), Pseudomonas (P. aeruginosa, P. putida), Stapylococcus (S. aureus) and Rhodococcus sp., was identified in this study during the process of biofiltration. Their amount in the biological packing material changed from 1.6 × 107 to 3.7 × 1011 CFU g−1. PMID:26019659

Research into acetone removal from air by biofiltration using a biofilter with straight structure plates.

PubMed

Baltrėnas, Pranas; Zagorskis, Alvydas; Misevičius, Antonas

2015-03-04

The biological air treatment method is based on the biological destruction of organic compounds using certain cultures of microorganisms. This method is simple and may be applied in many branches of industry. The main element of biological air treatment devices is a filter charge. Tests were carried out using a new-generation laboratory air purifier with a plate structure. This purifier is called biofilter. The biofilter has a special system for packing material humidification which does not require additional energy inputs. In order to extend the packing material's durability, it was composed of thermally treated birch fibre. Pollutant (acetone) biodegradation occurred on thermally treated wood fibre in this research. According to the performed tests and the received results, the process of biodestruction was highly efficient. When acetone was passed through biofilter's packing material at 0.08 m s -1 rate, the efficiency of the biofiltration process was from 70% up to 90%. The species of bacteria capable of removing acetone vapour from the air, i.e. Bacillus ( B. cereus , B. subtilis ), Pseudomonas ( P. aeruginosa , P. putida ), Stapylococcus ( S. aureus ) and Rhodococcus sp., was identified in this study during the process of biofiltration. Their amount in the biological packing material changed from 1.6 × 10 7 to 3.7 × 10 11 CFU g -1 .

Elucidation of Factors Effecting Enzymatic Saccharification using Transgenic Hardwoods

NASA Astrophysics Data System (ADS)

Min, Douyong

Three groups of transgenic wood samples were used as starting materials to elucidate the recalcitrance of enzymatic saccharification with/without pretreatments. The first group of transgenic wood samples is low lignin P. trichocarpa. The second group is low xylan P. trichocarpa. The third one is 12 hybrid poplars which have different levels of S/V ratio and lignin content. Four pretreatments were carried out in this research including dilute sulfuric acid, green liquor, auto hydrolysis and ozone delignification. The behavior among pretreatments as a function of removal of lignin appears to be different. Lignin is the major factor of recalcitrance of the lignocellulosic material to ethanol conversion process. Xylan also plays key role in this process. In addition, the crude milled wood lignin was isolated from these three groups of transgenic samples. Lignin carbohydrate complexes was characterized by 1H-13C HMQC and 13C NMR. Thus the effect of LCCs on enzymatic saccharification was elucidated. High S/V ratio propels the lignin removal during pretreatments however; high S/V ratio retards the enzymatic saccharification on the lignocellulosic material without pretreatments. The level of LCCs linkages accounts for additional recalcitrance of the lignocellulosic material to ethanol conversion process. The amount of LCCs linkages is affected by xylan content, lignin content and S/V ratio.

Design and implementation of a system for laser assisted milling of advanced materials

NASA Astrophysics Data System (ADS)

Wu, Xuefeng; Feng, Gaocheng; Liu, Xianli

2016-09-01

Laser assisted machining is an effective method to machine advanced materials with the added benefits of longer tool life and increased material removal rates. While extensive studies have investigated the machining properties for laser assisted milling(LAML), few attempts have been made to extend LAML to machining parts with complex geometric features. A methodology for continuous path machining for LAML is developed by integration of a rotary and movable table into an ordinary milling machine with a laser beam system. The machining strategy and processing path are investigated to determine alignment of the machining path with the laser spot. In order to keep the material removal temperatures above the softening temperature of silicon nitride, the transformation is coordinated and the temperature interpolated, establishing a transient thermal model. The temperatures of the laser center and cutting zone are also carefully controlled to achieve optimal machining results and avoid thermal damage. These experiments indicate that the system results in no surface damage as well as good surface roughness, validating the application of this machining strategy and thermal model in the development of a new LAML system for continuous path processing of silicon nitride. The proposed approach can be easily applied in LAML system to achieve continuous processing and improve efficiency in laser assisted machining.

Advanced Technology for Pyrotechnic Mixtures and Munitions

DTIC Science & Technology

1977-07-01

or at ambient I ,/ BLENDING AND CASTING CURING REMOVING MOLD WAFER MANUFACTURING ? / I / SI ,/ iAUTOMATIC LOADING Figure 1. Plastic Bonded Starter Mix...material (fines) is recycled through the compacting rollers. asshwn The Chilsonator used at EA consisted only of the compaction rollers and the controls ...standardized process controls . Oversize material is pulverized and combined with the undersize material for s" ,regranulation in another batch. 2 ,Both the

Acid hydrolysis of cellulose to yield glucose

DOEpatents

Tsao, George T.; Ladisch, Michael R.; Bose, Arindam

1979-01-01

A process to yield glucose from cellulose through acid hydrolysis. Cellulose is recovered from cellulosic materials, preferably by pretreating the cellulosic materials by dissolving the cellulosic materials in Cadoxen or a chelating metal caustic swelling solvent and then precipitating the cellulose therefrom. Hydrolysis is accomplished using an acid, preferably dilute sulfuric acid, and the glucose is yielded substantially without side products. Lignin may be removed either before or after hydrolysis.

Carbon dioxide capture process with regenerable sorbents

DOEpatents

Pennline, Henry W.; Hoffman, James S.

2002-05-14

A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

CO2-Triggered Switchable Solvents, Surfactants, and Other Materials

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

Jessop, Philip G.; Mercer, Sean; Heldebrant, David J.

2012-06-14

Waste CO2 at atmospheric pressure can be used to trigger dramatic changes in the properties of certain switchable materials. Compared to other triggers such as light, acids, oxidants, CO2 has the advantages that it is inexpensive, nonhazardous, non-accumulating in the system, easily removed, and it does not require the material to be transparent. Known CO2-triggered switchable materials 10 now include solvents, surfactants, solutes, catalysts, particles, polymers, and gels. The added flexibility of switchable materials represents a new strategy for minimizing energy and material consumption in process and product design.

40 CFR 60.101 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... crude oil removed from the earth and the oils derived from tar sands, shale, and coal. (c) Process gas..., or react with a contact material suspended in a fluidized bed to improve feedstock quality for...

Apparatus and process for removing a predetermined portion of reflective material from mirror

DOEpatents

Perry, Stephen J.; Steinmetz, Lloyd L.

1994-01-01

An apparatus and process are disclosed for removal of a stripe of soft reflective material of uniform width from the surface of a mirror by using a blade having a large included angle to inhibit curling of the blade during the cutting operation which could result in damage to the glass substrate of the mirror. The cutting blade is maintained at a low blade angle with respect to the mirror surface to produce minimal chipping along the cut edge and to minimize the force exerted on the coating normal to the glass surface which could deform the flat mirror. The mirror is mounted in a cutting mechanism containing a movable carriage on which the blade is mounted to provide very accurate straightness of the travel of the blade along the mirror.

Spin-on metal oxide materials with high etch selectivity and wet strippability

NASA Astrophysics Data System (ADS)

Yao, Huirong; Mullen, Salem; Wolfer, Elizabeth; McKenzie, Douglas; Rahman, Dalil; Cho, JoonYeon; Padmanaban, Munirathna; Petermann, Claire; Hong, SungEun; Her, YoungJun

2016-03-01

Metal oxide or metal nitride films are used as hard mask materials in semiconductor industry for patterning purposes due to their excellent etch resistances against the plasma etches. Chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques are usually used to deposit the metal containing materials on substrates or underlying films, which uses specialized equipment and can lead to high cost-of-ownership and low throughput. We have reported novel spin-on coatings that provide simple and cost effective method to generate metal oxide films possessing good etch selectivity and can be removed by chemical agents. In this paper, new spin-on Al oxide and Zr oxide hard mask formulations are reported. The new metal oxide formulations provide higher metal content compared to previously reported material of specific metal oxides under similar processing conditions. These metal oxide films demonstrate ultra-high etch selectivity and good pattern transfer capability. The cured films can be removed by various chemical agents such as developer, solvents or wet etchants/strippers commonly used in the fab environment. With high metal MHM material as an underlayer, the pattern transfer process is simplified by reducing the number of layers in the stack and the size of the nano structure is minimized by replacement of a thicker film ACL. Therefore, these novel AZ® spinon metal oxide hard mask materials can potentially be used to replace any CVD or ALD metal, metal oxide, metal nitride or spin-on silicon-containing hard mask films in 193 nm or EUV process.

Centrifugal accelerator, system and method for removing unwanted layers from a surface

DOEpatents

Foster, Christopher A.; Fisher, Paul W.

1995-01-01

A cryoblasting process having a centrifugal accelerator for accelerating frozen pellets of argon or carbon dioxide toward a target area utilizes an accelerator throw wheel designed to induce, during operation, the creation of a low-friction gas bearing within internal passages of the wheel which would otherwise retard acceleration of the pellets as they move through the passages. An associated system and method for removing paint from a surface with cryoblasting techniques involves the treating, such as a preheating, of the painted surface to soften the paint prior to the impacting of frozen pellets thereagainst to increase the rate of paint removal. A system and method for producing large quantities of frozen pellets from a liquid material, such as liquid argon or carbon dioxide, for use in a cryoblasting process utilizes a chamber into which the liquid material is introduced in the form of a jet which disintegrates into droplets. A non-condensible gas, such as inert helium or air, is injected into the chamber at a controlled rate so that the droplets freeze into bodies of relatively high density.

Method for processing aqueous wastes

DOEpatents

Pickett, John B.; Martin, Hollis L.; Langton, Christine A.; Harley, Willie W.

1993-01-01

A method for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream. The filtered material is added to the sludge of the concentrated waste stream. The method is also applicable to the treatment and removal of soluble uranium from aqueous streams, such that the treated stream may be used as a potable water supply.

Removing Beam Current Artifacts in Helium Ion Microscopy: A Comparison of Image Processing Techniques.

PubMed

Barlow, Anders J; Portoles, Jose F; Sano, Naoko; Cumpson, Peter J

2016-10-01

The development of the helium ion microscope (HIM) enables the imaging of both hard, inorganic materials and soft, organic or biological materials. Advantages include outstanding topographical contrast, superior resolution down to <0.5 nm at high magnification, high depth of field, and no need for conductive coatings. The instrument relies on helium atom adsorption and ionization at a cryogenically cooled tip that is atomically sharp. Under ideal conditions this arrangement provides a beam of ions that is stable for days to weeks, with beam currents in the order of picoamperes. Over time, however, this stability is lost as gaseous contamination builds up in the source region, leading to adsorbed atoms of species other than helium, which ultimately results in beam current fluctuations. This manifests itself as horizontal stripe artifacts in HIM images. We investigate post-processing methods to remove these artifacts from HIM images, such as median filtering, Gaussian blurring, fast Fourier transforms, and principal component analysis. We arrive at a simple method for completely removing beam current fluctuation effects from HIM images while maintaining the full integrity of the information within the image.

Rapid fabrication of a silicon modification layer on silicon carbide substrate.

PubMed

Bai, Yang; Li, Longxiang; Xue, Donglin; Zhang, Xuejun

2016-08-01

We develop a kind of magnetorheological (MR) polishing fluid for the fabrication of a silicon modification layer on a silicon carbide substrate based on chemical theory and actual polishing requirements. The effect of abrasive concentration in MR polishing fluid on material removal rate and removal function shape is investigated. We conclude that material removal rate will increase and tends to peak value as the abrasive concentration increases to 0.3 vol. %, and the removal function profile will become steep, which is a disadvantage to surface frequency error removal at the same time. The removal function stability is also studied and the results show that the prepared MR polishing fluid can satisfy actual fabrication requirements. An aspheric reflective mirror of silicon carbide modified by silicon is well polished by combining magnetorheological finishing (MRF) using two types of MR polishing fluid and computer controlled optical surfacing (CCOS) processes. The surface accuracy root mean square (RMS) is improved from 0.087λ(λ=632.8  nm) initially to 0.020λ(λ=632.8  nm) in 5.5 h total and the tool marks resulting from MRF are negligible. The PSD analysis results also shows that the final surface is uniformly polished.

Sintering of Lunar and Simulant Glass

NASA Technical Reports Server (NTRS)

Cooper, Bonnie L.

2007-01-01

Most oxygen-extraction techniques are temperature-dependent, with higher temperatures resulting in higher oxygen yield. An example is hydrogen reduction, in which the optimum process temperature is 1050 C. However, glass-rich lunar soil begins to show the effects of sintering at temperatures of 900 C or lower. Sintering welds particles together due to viscous relaxation of the glass in the sample. One approach to avoid problems related to sintering, such as difficulty in removing waste material from the reactor, is to keep the soil in motion. One of several methods being studied to accomplish this is fluidized-bed processing techniques, in which the grains are kept in motion by the action of flowing reductant gas. The spent material can be removed from the chamber while still fluidized, or the fluidizing motion can continue until the material has cooled below approx. 500 C. Until end-to-end prototypes are built that can remove the heated soil, the most practical option is to keep the bed fluidized while cooling the waste material. As ISRU technology advances, another option will become valuable, which is to intentionally sinter the material to a great enough extent that it becomes a brick. The free iron in lunar soil is magnetic, and ferromagnetic bricks can be manipulated by robotic systems using electromagnetic end effectors. Finally, if an electromagnetic field is applied to the soil while the brick is being formed, the brick itself will become a magnet. This property can be used to create self-aligning bricks or other building materials that do not require fasteners. Although sintering creates a challenge for early lunar surface systems, knowledge gained during prototype development will be valuable for the advanced lunar outpost.

Ultrashort pulse high repetition rate laser system for biological tissue processing

DOEpatents

Neev, Joseph; Da Silva, Luiz B.; Matthews, Dennis L.; Glinsky, Michael E.; Stuart, Brent C.; Perry, Michael D.; Feit, Michael D.; Rubenchik, Alexander M.

1998-01-01

A method and apparatus is disclosed for fast, efficient, precise and damage-free biological tissue removal using an ultrashort pulse duration laser system operating at high pulse repetition rates. The duration of each laser pulse is on the order of about 1 fs to less than 50 ps such that energy deposition is localized in a small depth and occurs before significant hydrodynamic motion and thermal conduction, leading to collateral damage, can take place. The depth of material removed per pulse is on the order of about 1 micrometer, and the minimal thermal and mechanical effects associated with this ablation method allows for high repetition rate operation, in the region 10 to over 1000 Hertz, which, in turn, achieves high material removal rates. The input laser energy per ablated volume of tissue is small, and the energy density required to ablate material decreases with decreasing pulse width. The ablation threshold and ablation rate are only weakly dependent on tissue type and condition, allowing for maximum flexibility of use in various biological tissue removal applications. The use of a chirped-pulse amplified Titanium-doped sapphire laser is disclosed as the source in one embodiment.

Ultrashort pulse high repetition rate laser system for biological tissue processing

DOEpatents

Neev, J.; Da Silva, L.B.; Matthews, D.L.; Glinsky, M.E.; Stuart, B.C.; Perry, M.D.; Feit, M.D.; Rubenchik, A.M.

1998-02-24

A method and apparatus are disclosed for fast, efficient, precise and damage-free biological tissue removal using an ultrashort pulse duration laser system operating at high pulse repetition rates. The duration of each laser pulse is on the order of about 1 fs to less than 50 ps such that energy deposition is localized in a small depth and occurs before significant hydrodynamic motion and thermal conduction, leading to collateral damage, can take place. The depth of material removed per pulse is on the order of about 1 micrometer, and the minimal thermal and mechanical effects associated with this ablation method allows for high repetition rate operation, in the region 10 to over 1000 Hertz, which, in turn, achieves high material removal rates. The input laser energy per ablated volume of tissue is small, and the energy density required to ablate material decreases with decreasing pulse width. The ablation threshold and ablation rate are only weakly dependent on tissue type and condition, allowing for maximum flexibility of use in various biological tissue removal applications. The use of a chirped-pulse amplified Titanium-doped sapphire laser is disclosed as the source in one embodiment. 8 figs.

Method and apparatus for incinerating hazardous waste

DOEpatents

Korenberg, Jacob

1990-01-01

An incineration apparatus and method for disposal of infectious hazardous waste including a fluidized bed reactor containing a bed of granular material. The reactor includes a first chamber, a second chamber, and a vertical partition separating the first and second chambers. A pressurized stream of air is supplied to the reactor at a sufficient velocity to fluidize the granular material in both the first and second chambers. Waste materials to be incinerated are fed into the first chamber of the fluidized bed, the fine waste materials being initially incinerated in the first chamber and subsequently circulated over the partition to the second chamber wherein further incineration occurs. Coarse waste materials are removed from the first chamber, comminuted, and recirculated to the second chamber for further incineration. Any partially incinerated waste materials and ash from the bottom of the second chamber are removed and recirculated to the second chamber for further incineration. This process is repeated until all infectious hazardous waste has been completely incinerated.

Evaluation of roll-off trailers in small-diameter applications

Treesearch

Bob Rummer; John Klepac

2003-01-01

Concern about wildfire in overstocked forests of the western U.S. has led to increased emphasis on extraction of small-diameter material. Removing this material improves forest health, reduces fuel loading, and may generate value that can be used to offset the costs of operation. However, the cost of small-diameter operations (both in-woods and secondary processing)...

Investigation of contact pressure and influence function model for soft wheel polishing.

PubMed

Rao, Zhimin; Guo, Bing; Zhao, Qingliang

2015-09-20

The tool influence function (TIF) is critical for calculating the dwell-time map to improve form accuracy. We present the TIF for the process of computer-controlled polishing with a soft polishing wheel. In this paper, the static TIF was developed based on the Preston equation. The pressure distribution was verified by the real removal spot section profiles. According to the experiment measurements, the pressure distribution simulated by Hertz contact theory was much larger than the real contact pressure. The simulated pressure distribution, which was modeled by the Winkler elastic foundation for a soft polishing wheel, matched the real contact pressure. A series of experiments was conducted to obtain the removal spot statistical properties for validating the relationship between material removal and processing time and contact pressure and relative velocity, along with calculating the fitted parameters to establish the TIF. The developed TIF predicted the removal character for the studied soft wheel polishing.

Electrochemical wastewater treatment: influence of the type of carbon and of nitrogen on the organic load removal.

PubMed

Fernandes, Annabel; Coelho, João; Ciríaco, Lurdes; Pacheco, Maria José; Lopes, Ana

2016-12-01

Boron-doped diamond (BDD) and Ti/Pt/PbO 2 anodes were utilized to perform the electrodegradation of synthetic samples containing humic acid in the presence of different organic and inorganic carbon-containing and nitrogen-containing compounds. The influence of the chloride ion in the degradation process of the different synthetic samples was also assessed. The results showed that the anodic oxidation process can efficiently degrade recalcitrant compounds such as humic acid. The presence of carbonate in solution enhances the nitrogen removal, whereas it hinders the oxidation of the organic compounds. When organic nitrogen is present, it is converted to NH 4 + , which in turn is oxidized to nitrate and to volatile nitrogen compounds. Hydroxyl radicals are more prone to oxidize the organic nitrogen than the ammonium nitrogen. The presence of chloride enhances the organic matter and nitrogen removal rates, BDD being the anode material that yields the highest removals.

Final Report on Portable Laser Coating Removal Systems Field Demonstrations and Testing

NASA Technical Reports Server (NTRS)

Rothgeb, Matthew J.; McLaughlin, Russell L.

2008-01-01

Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment and small components results in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the EPA reduced the permissible exposure limit (PEL) for hexavalent chromium. The new standard lowers OSHA's PEL for hexavalent chromium from 52 to 5 micrograms of Cr(V1) per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in the pretreatment and primer coatings used within the Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient and environmentally preferable manner. The use of laser energy to remove prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation and non destructive evaluation is a relatively new technology that has shown itself to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The development of a Portable Laser Coating Removal System (PLCRS) started as the goal of a Joint Group on Pollution Prevention (JG-PP) project, led by the Air Force, where several types of lasers in several configurations were thoroughly evaluated. Following this project, NASA decided to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation. Due to the fact that the technology lends itself to a bide variety of processes, several site demonstrations were organized in order to allow for greater evaluation of the laser systems across NASA. The project consisted of an introductory demonstration and a more in-depth evaluation at Wright-Patterson Air Force Base. Additionally, field demonstrations occurred at Glenn Research Center and Kennedy Space Center. During these demonstrations several NASA specific applications were evaluated, including the removal of coatings within Orbiter tile cavities and Teflon from Space Shuttle Main Engine gaskets, removal of heavy grease from Solid Rocket Booster components and the removal of coatings on weld lines for Shuttle and general ground service equipment for non destructive evaluation (NDE). In addition, several general industry applications such as corrosion removal, structural coating removal, weld-line preparation and surface cleaning were evaluated. This included removal of coatings and corrosion from surfaces containing lead-based coatings and applications similar to launch-structure maintenance and Crawler maintenance. During the project lifecycle, an attempt was made to answer process specific concerns and questions as they arose. Some of these initially unexpected questions concerned the effects lasers might have on substrates used on flight equipment including strength, surface re-melting, substrate temperature and corrosion resistance effects. Additionally a concern was PPE required for operating such a system including eye, breathing and hearing protection. Most of these questions although not initially planned, were fully explored as a part of this project. Generally the results from tesng were very positive. Corrosion was effectively removed from steel, but less successfully from aluminum alloys. Coatings were able to be removed, with varying results, generally dark, matte and thin coatings were easier to remove. Steel and aluminum panels were able to be cleaned for welding, with no known deleterious effects and weld-lines were able to have coatings removed in critical areas for NDE while saving time as compared to other methods.

Fabrication of the tea saponin functionalized reduced graphene oxide for fast adsorptive removal of Cd(II) from water

NASA Astrophysics Data System (ADS)

Li, Zhigang; Liu, Zhifeng; Wu, Zhibin; Zeng, Guangming; Shao, Binbin; Liu, Yujie; Jiang, Yilin; Zhong, Hua; Liu, Yang

2018-05-01

A novel graphene-based material of tea saponin functionalized reduced graphene oxide (TS-RGO) was synthesized via a facil thermal method, and it was characterized as the absorbent for Cd(II) removal from aqueous solutions. The factors on adsorption process including solution pH, contact time, initial concentration of Cd(II) and background electrolyte cations were studied to optimize the conditions for maximum adsorption at room temperature. The results indicated that Cd(II) adsorption was strongly dependent on pH and could be strongly affected by background electrolytes and ionic strength. The optimal pH and required equilibrium time was 6.0 and 10 min, respectively. The Cd(II) removal decreased with the presence of background electrolyte cations (Na+ < Ca2+ < Al3+). The adsorption kinetics of Cd(II) followed well with the pseudo-second-order model. The adsorption isotherm fitted well to the Langmuir model, indicating that the adsorption was a monolayer adsorption process occurred on the homogeneous surfaces of TS-RGO. The maximum monolayer adsorption capacity was 127 mg/g at 313 K and pH 6.0. Therefore, the TS-RGO was considered to be a cost-effective and promising material for the removal of Cd(II) from wastewater.

A novel solid-state fractionation of naphthenic acid fraction components from oil sands process-affected water.

PubMed

Mohamed, Mohamed H; Wilson, Lee D; Shah, Jaimin R; Bailey, Jon; Peru, Kerry M; Headley, John V

2015-10-01

Various sorbent materials were evaluated for the fractionation of naphthenic acid fraction components (NAFCs) from oil sand process-affected water (OSPW). The solid phase materials include activated carbon (AC), cellulose, iron oxides (magnetite and goethite), polyaniline (PANI) and three types of biochar derived from biomass (BC-1; rice husks, BC-2; acacia low temperature and BC-3; acacia high temperature). NAFCs were semi-quantified using electrospray ionization high resolution Orbitrap mass spectrometry (ESI-MS) and the metals were assessed by inductively coupled plasma optical emission spectrometry (ICP-OES). The average removal efficacy of NAFCs by AC was 95%. The removal efficacy decreased in the following order: AC, BC-1>BC-2, BC-3, goethite>PANI>cellulose, magnetite. The removal of metals did not follow a clear trend; however, there was notable leaching of potassium by AC and biochar samples. The bound NAFCs by AC were desorbed efficiently with methanol. Methanol regeneration and recycling of AC revealed 88% removal on the fourth cycle; a 4.4% decrease from the first cycle. This fractionation method represents a rapid, cost-effective, efficient, and green strategy for NAFCs from OSPW, as compared with conventional solvent extraction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of traces of toluene and p-xylene in indoor air using biofiltration and a hybrid system (biofiltration + adsorption).

PubMed

Luengas, Angela Tatiana; Hort, Cécile; Platel, Vincent; Elias, Ana; Barona, Astrid; Moynault, Laurent

2017-04-01

Biofiltration technology and the hybrid system combining biofiltration and adsorption (onto activated carbon) were compared as possible methods to toluene and p-xylene at parts per million concentration levels (2-45 and 1-33 ppb, respectively). An organic material was used as packing material for the biofiltration process. Even at low empty bed residence times (EBRTs) and concentrations, toluene removal efficiency reached 100% and p-xylene showed an increasing trend on their removal efficiency over the time using biofiltration. The assessment of by-products and particle generation by the biofilter and the hybrid system were taken into account. Acetone and acetic acid were identified as by-products of the biofilter. Particle emissions in the range of 0.03 to 10 μm were recorded for both systems.

Development of high gradient magnetic separation system for removing the metallic wear debris to be present in highly viscous fluid

NASA Astrophysics Data System (ADS)

Hayashi, S.; Mishima, F.; Akiyama, Y.; Nishijima, S.

2010-11-01

In the industrial plants processing highly viscous fluid such as foods or industrial materials, there is an issue of contamination by metallic wear debris originating from pipe of manufacturing line. It is necessary to remove the metallic wear debris in highly viscous fluid, since these debris causes quality loss. In this study, we developed a high gradient magnetic separation system by using superconducting magnet to remove the metallic wear debris. The particle trajectory simulation and the magnetic separation experiment were conducted with polyvinyl alcohol as a model material. As a result, ca. 100% and 92.2% of the separation efficiency was achieved respectively for the highly viscous fluid of 1 Pa s and 6 Pa s in viscosity, with 14 and 30 mesh magnetic filters.

Process development and monitoring in stripping of a highly transparent polymeric paint with ns-pulsed fiber laser

NASA Astrophysics Data System (ADS)

Jasim, Halah A.; Demir, Ali Gökhan; Previtali, Barbara; Taha, Ziad A.

2017-08-01

Laser paint removal was studied with ns-pulsed fiber laser on the combination of 20 μm-thick, white polymeric paint and Al alloy substrate. The response of paint to single pulse ablation was evaluated to measure the ablated zone dimensions. With this information, the effect of overlap, number of passes and pulse repetition rate was evaluated to investigate machining depth. Optical emission spectroscopy was used to investigate the machining behaviour as well as to propose monitoring strategies. The results showed that despite the high transparency of the paint, complete paint removal can be achieved with reduced substrate damage (Sa = 1.3 μm). The emission spectroscopy can be used to identify removal completion as well as the reach of substrate material. The observations were also used to explain a paint removal mechanism based on thermal expansion of the paint and mechanical action provided by the plasma expansion from the substrate material.

Exploration of material removal rate of srf elliptical cavities as a function of media type and cavity shape on niobium and copper using centrifugal barrel polishing (cbp)

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

Palczewski, Ari; Ciovati, Gianluigi; Li, Yongming

Centrifugal barrel polishing (cbp) for SRF application is becoming more wide spread as the technique for cavity surface preparation. CBP is now being used in some form at SRF laboratories around the world including in the US, Europe and Asia. Before the process can become as mature as wet chemistry like eletro-polishing (EP) and buffered chemical polishing (BCP) there are many questions which remain unanswered. One of these topics includes the uniformity of removal as a function of cavity shape and material type. In this presentation we show CBP removal rates for various media types on 1.3 GHz TESLA andmore » 1.5 GHz CEBAF large/fine grain niobium cavities, and 1.3GHz low surface field copper cavity. The data will also include calculated RF frequency shift modeling non-uniform removal as a function of cavity position and comparing them with CBP results.« less

Recycling of aluminium scrap for secondary Al-Si alloys.

PubMed

Velasco, Eulogio; Nino, Jose

2011-07-01

An increasing amount of recycled aluminium is going into the production of aluminium alloy used for automotive applications. In these applications, it is necessary to control and remove alloy impurities and inclusions. Cleaning and fluxing processes are widely used during processing of the alloys for removal of inclusions, hydrogen and excess of magnesium. These processes use salt fluxes based in the system NaCl-KCl, injection of chlorine or mixture of chlorine with an inert gas. The new systems include a graphite wand and a circulation device to force convection in the melt and permit the bubbling and dispersion of reactive and cleaning agents. This paper discusses the recycling of aluminium alloys in rotary and reverberatory industrial furnaces. It focuses on the removal of magnesium during the melting process. In rotary furnaces, the magnesium lost is mainly due to the oxidation process at high temperatures. The magnesium removal is carried out by the reaction between chlorine and magnesium, with its efficiency associated to kinetic factors such as concentration of magnesium, mixing, and temperature. These factors are also related to emissions generated during the demagging process. Improvements in the metallic yield can be reached in rotary furnaces if the process starts with a proper salt, with limits of addition, and avoiding long holding times. To improve throughput in reverberatories, start the charging with high magnesium content material and inject chlorine gas if the molten metal is at the right temperature. Removal of magnesium through modern technologies can be efficiently performed to prevent environmental problems.

Fluidized-Bed Cleaning of Silicon Particles

NASA Technical Reports Server (NTRS)

Rohatgi, Naresh K.; Hsu, George C.

1987-01-01

Fluidized-bed chemical cleaning process developed to remove metallic impurities from small silicon particles. Particles (250 micrometer in size) utilized as seed material in silane pyrolysis process for production of 1-mm-size silicon. Product silicon (1 mm in size) used as raw material for fabrication of solar cells and other semiconductor devices. Principal cleaning step is wash in mixture of hydrochloric and nitric acids, leaching out metals and carrying them away as soluble chlorides. Particles fluidized by cleaning solution to assure good mixing and uniform wetting.

Bagless transfer process and apparatus for radioactive waste confinement

DOEpatents

Maxwell, D.N.; Hones, R.H.; Rogers, M.L.

1998-04-14

A process and apparatus are provided for removing radioactive material from a glovebox, placing the material in a stainless steel storage vessel in communication with the glovebox, and sealing the vessel with a welded plug. The vessel is then severed along the weld, a lower half of the plug forming a closure for the vessel. The remaining welded plug half provides a seal for the remnant portion of the vessel and thereby maintains the sealed integrity of the glovebox. 7 figs.

Bagless transfer process and apparatus for radioactive waste confinement

DOEpatents

Maxwell, David N.; Hones, Robert H.; Rogers, M. Lane

1998-01-01

A process and apparatus is provided for removing radioactive material from a glovebox, placing the material in a stainless steel storage vessel in communication with the glovebox, and sealing the vessel with a welded plug. The vessel is then severed along the weld, a lower half of the plug forming a closure for the vessel. The remaining welded plug half provides a seal for the remnant portion of the vessel and thereby maintains the sealed integrity of the glovebox.

Cooling and solidification of heavy hydrocarbon liquid streams

DOEpatents

Antieri, Salvatore J.; Comolli, Alfred G.

1983-01-01

A process and apparatus for cooling and solidifying a stream of heavy hydrocarbon material normally boiling above about 850.degree. F., such as vacuum bottoms material from a coal liquefaction process. The hydrocarbon stream is dropped into a liquid bath, preferably water, which contains a screw conveyor device and the stream is rapidly cooled, solidified and broken therein to form discrete elongated particles. The solid extrudates or prills are then dried separately to remove substantially all surface moisture, and passed to further usage.

Research on subsurface deformed layer in ultra-precision cutting of single crystal copper by focused ion beam etching method

NASA Astrophysics Data System (ADS)

Chen, Y.; Huang, X. J.; Kong, J. X.

2018-03-01

In this paper, the focused ion beam was used to study the subsurface deformed layer of single crystal copper caused by the nanoscale single-point diamond fly cutting, and the possibility of using nanometer ultra-precision cutting to remove the larger deformation layer caused by traditional rough cutting process was explored. The maximum cutting thickness of single-point diamond cutting was about 146 nm, and the surface of the single-crystal copper after cutting was etched and observed by using the focused ion beam method. It was found that the morphology of the near-surface layer and the intermediate layer of the copper material were larger differences: the near-surface of the material was smaller and more compact, and the intermediate material layer of the material was more coarse sparse. The results showed that the traditional precision cutting would residual significant subsurface deformed layer and the thickness was on micron level. Even more, the subsurface deformed layer was obviously removed from about 12μm to 5μm after single-point diamond fly cutting in this paper. This paper proved that the large-scale subsurface deformed layer caused by traditional cutting process could be removed by nanometer ultra-precision cutting. It was of great significance to further establish the method that control of the deformation of weak rigid components by reducing the depth of the subsurface deformed layers.

The improvement of laser induced damage resistance of optical workpiece surface by hydrodynamic effect polishing

NASA Astrophysics Data System (ADS)

Peng, Wenqiang; Guan, Chaoliang; Li, Shengyi; Wang, Zhuo

2016-10-01

Surface and subsurface damage in optical element will greatly decrease the laser induced damage threshold (LIDT) in the intense laser optical system. Processing damage on the workpiece surface can be inevitably caused when the material is removed in brittle or plastic mode. As a non-contact polishing technology, hydrodynamic effect polishing (HEP) shows very good performance on generating an ultra-smooth surface without damage. The material is removed by chemisorption between nanoparticle and workpiece surface in the elastic mode in HEP. The subsurface damage and surface scratches can be effectively removed after the polishing process. Meanwhile ultra-smooth surface with atomic level surface roughness can be achieved. To investigate the improvement of LIDT of optical workpiece, polishing experiment was conducted on a magnetorheological finishing (MRF) silica glass sample. AFM measurement results show that all the MRF directional plastic marks have been removed clearly and the root-mean-square (rms) surface roughness has decreased from 0.673nm to 0.177nm after HEP process. Laser induced damage experiment was conducted with laser pulse of 1064nm wavelength and 10ns time width. Compared with the original state, the LEDT of the silica glass sample polished by HEP has increased from 29.78J/cm2 to 45.47J/cm2. It demonstrates that LIDT of optical element treated by HEP can be greatly improved for ultra low surface roughness and nearly defect-free surface/subsurface.

Significance, evolution and recent advances in adsorption technology, materials and processes for desalination, water softening and salt removal.

PubMed

Alaei Shahmirzadi, Mohammad Amin; Hosseini, Seyed Saeid; Luo, Jianquan; Ortiz, Inmaculada

2018-06-01

Desalination and softening of sea, brackish, and ground water are becoming increasingly important solutions to overcome water shortage challenges. Various technologies have been developed for salt removal from water resources including multi-stage flash, multi-effect distillation, ion exchange, reverse osmosis, nanofiltration, electrodialysis, as well as adsorption. Recently, removal of solutes by adsorption onto selective adsorbents has shown promising perspectives. Different types of adsorbents such as zeolites, carbon nanotubes (CNTs), activated carbons, graphenes, magnetic adsorbents, and low-cost adsorbents (natural materials, industrial by-products and wastes, bio-sorbents, and biopolymer) have been synthesized and examined for salt removal from aqueous solutions. It is obvious from literature that the existing adsorbents have good potentials for desalination and water softening. Besides, nano-adsorbents have desirable surface area and adsorption capacity, though are not found at economically viable prices and still have challenges in recovery and reuse. On the other hand, natural and modified adsorbents seem to be efficient alternatives for this application compared to other types of adsorbents due to their availability and low cost. Some novel adsorbents are also emerging. Generally, there are a few issues such as low selectivity and adsorption capacity, process efficiency, complexity in preparation or synthesis, and problems associated to recovery and reuse that require considerable improvements in research and process development. Moreover, large-scale applications of sorbents and their practical utility need to be evaluated for possible commercialization and scale up. Copyright © 2018 Elsevier Ltd. All rights reserved.

Liquid-assisted laser ablation of advanced ceramics and glass-ceramic materials

NASA Astrophysics Data System (ADS)

Garcia-Giron, A.; Sola, D.; Peña, J. I.

2016-02-01

In this work, results obtained by laser ablation of advanced ceramics and glass-ceramic materials assisted by liquids are reported. A Q-switched Nd:YAG laser at its fundamental wavelength of 1064 nm with pulse-width in the nanosecond range was used to machine the materials, which were immersed in water and ethylene glycol. Variation in geometrical parameters, morphology, and ablation yields were studied by using the same laser working conditions. It was observed that machined depth and removed volume depended on the thermal, optical, and mechanical features of the processed materials as well as on the properties of the surrounding medium in which the laser processing was carried out. Variation in ablation yields was studied in function of the liquid used to assist the laser process and related to refractive index and viscosity. Material features and working conditions were also related to the obtained results in order to correlate ablation parameters with respect to the hardness of the processed materials.

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process.

PubMed

Dhandapani, N V; Thangarasu, V S; Sureshkannan, G

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

PubMed Central

Dhandapani, N. V.; Thangarasu, V. S.; Sureshkannan, G.

2015-01-01

This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results. PMID:26881267

Arsenic removal using steel manufacturing byproducts as permeable reactive materials in mine tailing containment systems.

PubMed

Ahn, Joo Sung; Chon, Chul-Min; Moon, Hi-Soo; Kim, Kyoung-Woong

2003-05-01

Steel manufacturing byproducts were tested as a means of treating mine tailing leachate with a high As concentration. Byproduct materials can be placed in situ as permeable reactive barriers to control the subsurface release of leachate from tailing containment systems. The tested materials had various compositions of elemental Fe, Fe oxides, Ca-Fe oxides and Ca hydroxides typical of different steel manufacturing processes. Among these materials, evaporation cooler dust (ECD), oxygen gas sludge (OGS), basic oxygen furnace slag (BOFS) and to a lesser degree, electrostatic precipitator dust (EPD) effectively removed both As(V) and As(III) during batch experiments. ECD, OGS and BOFS reduced As concentrations to <0.5mg/l from 25mg/l As(V) or As(III) solution in 72 h, exhibiting higher removal capacities than zero-valent iron. High Ca concentrations and alkaline conditions (pH ca. 12) provided by the dissolution of Ca hydroxides may promote the formation of stable, sparingly soluble Ca-As compounds. When initial pH conditions were adjusted to 4, As reduction was enhanced, probably by adsorption onto iron oxides. The elution rate of retained As from OGS and ECD decreased with treatment time, and increasing the residence time in a permeable barrier strategy would be beneficial for the immobilization of As. When applied to real tailing leachate, ECD was found to be the most efficient barrier material to increase pH and to remove As and dissolved metals.

Possible Responsibility of Silicone Materials for Degradation of the CO2 Removal System in the International Space Station

NASA Technical Reports Server (NTRS)

Baeza, Mario; Sharma, Hemant; Borrok, David; Ren, Mingua; Pannell, Keith

2011-01-01

From data concerning the degradation of the CO2 removal system in the International Space Station (ISS) two important features were apparent: (1) The atmosphere within the International Space Station (ISS) contained many organic compounds including alcohols, halocarbons, aldehydes, esters, and ketones, inter alia. Various cyclosiloxanes Dn, hexamethylcyclotrisiloxane (D3) and its higher homologs (D4) and (D5) are also present presumably due to offgassing. (2) Screens within the zeolite-containing canisters, used for the removal of CO2, exhibited partial clogging due to zeolitic fragments (dust) along with "sticky" residues, that in toto significantly reduced the efficiency of the CO2 removal process. Samples of the ISS fresh zeolite, used zeolite, filter clogging zeolite particles and residual polymeric materials were examined using, inter alia, NMR, EM and HRSEM. These data were compared to equivalent samples obtained prior and subsequent to Dn polymerization experiments performed in our laboratories using the clean ISS zeolite samples as catalyst. Polysiloxane materials produced were essentially equivalent in the two cases and the EM images demonstrate a remarkable similarity between the ISS filter zeolite samples and the post-polymerization zeolite material from our experiments. In this regard even the changes in the Al/Si ratio from the virgin zeolite material to the filter samples and the post-polymerization laboratory samples samples is noteworthy. This research was supported by a contract from the Boeing Company

Thin film capillary process and apparatus

DOEpatents

Yu, Conrad M.

2003-11-18

Method and system of forming microfluidic capillaries in a variety of substrate materials. A first layer of a material such as silicon dioxide is applied to a channel etched in substrate. A second, sacrificial layer of a material such as a polymer is deposited on the first layer. A third layer which may be of the same material as the first layer is placed on the second layer. The sacrificial layer is removed to form a smooth walled capillary in the substrate.

Chlorpyrifos residual behaviors in field crops and transfers during duck pellet feed processing.

PubMed

Li, Rui; Wei, Wei; He, Liang; Hao, Lili; Ji, Xiaofeng; Zhou, Yu; Wang, Qiang

2014-10-22

Chlorpyrifos is a widely used organophosphorus pesticide in agricultural crops (including food) and animal feeds in China, resulting in heavy contamination. Many studies have focused on the food-processing effects on chlorpyrifos removal, but sufficient information is not observed for feed-processing steps. Here, chlorpyrifos residual behaviors in field crops and its transfers in duck pellet feed-processing steps were evaluated. In field trials, the highest residues for rice grain, shelled corn, and soybean seed were 12.0, 0.605, and 0.220 mg/kg, respectively. Residues of all rice grain and about half of shelled corn exceeded the maximum residue limits (MRLs) of China, and five soybean seeds exceeded the MRL of China. Chlorpyrifos residue was reduced 38.2% in brown rice after the raw rice grain was hulled. The residue in bran increased 71.2% after milling from brown rice. During the squashing step, the residue reduced 73.8% in soybean meal. The residues reduced significantly (23.7-36.8%) during the process of granulating for rice, maize, and soybean products. Comparatively, the grinding process showed only limited influence on chlorpyrifos removal (<10%). The residues of duck pellet feeds produced from highly contaminated raw materials of this study were 1.01 mg/kg (maize-soybean feed) and 3.20 mg/kg (rice-soybean feed), which were much higher than the generally accepted value (>0.1 mg/kg) for animal feeding. Chlorpyrifos residues were removed significantly by processing steps of pellet feeds, but the residue of raw materials was the determining factor for the safety of duck feeding.

Optimization of process parameters in drilling of fibre hybrid composite using Taguchi and grey relational analysis

NASA Astrophysics Data System (ADS)

Vijaya Ramnath, B.; Sharavanan, S.; Jeykrishnan, J.

2017-03-01

Nowadays quality plays a vital role in all the products. Hence, the development in manufacturing process focuses on the fabrication of composite with high dimensional accuracy and also incurring low manufacturing cost. In this work, an investigation on machining parameters has been performed on jute-flax hybrid composite. Here, the two important responses characteristics like surface roughness and material removal rate are optimized by employing 3 machining input parameters. The input variables considered are drill bit diameter, spindle speed and feed rate. Machining is done on CNC vertical drilling machine at different levels of drilling parameters. Taguchi’s L16 orthogonal array is used for optimizing individual tool parameters. Analysis Of Variance is used to find the significance of individual parameters. The simultaneous optimization of the process parameters is done by grey relational analysis. The results of this investigation shows that, spindle speed and drill bit diameter have most effect on material removal rate and surface roughness followed by feed rate.

Innovative and water based stripping approach for thick and bulk photoresists

NASA Astrophysics Data System (ADS)

Rudolph, Matthias; Schumann, Dirk; Thrun, Xaver; Esche, Silvio; Hohle, Christoph

2014-10-01

The usage of phase fluid based stripping agents to remove photoresists from silicon substrates was studied. Photoresists are required for many silicon based technologies such as MEMS patterning, 3D-Integration or frontend and backend of line semiconductor applications [1]. Although the use of resists is very common, their successful integration often depends on the ability to remove the resist after certain processing steps. On the one hand the resist is changing during subsequent process steps that can cause a thermally activated cross-linking which increases the stripping complexity. Resist removal is also challenging after the formation of a hard polymer surface layer during plasma or implant processes which is called skin or crust [2]. On the other hand the choice of stripping chemistry is often limited due to the presence of functional materials such as metals which can be damaged by aggressive stripping chemistries [3].

Pre-polishing on a CNC platform with bound abrasive contour tools

NASA Astrophysics Data System (ADS)

Schoeffer, Adrienne E.

2003-05-01

Deterministic micorgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-51.tm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an OptiproTM CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Prepolishing on a CNC platform with bound abrasive contour tools

NASA Astrophysics Data System (ADS)

Schoeffler, Adrienne E.; Gregg, Leslie L.; Schoen, John M.; Fess, Edward M.; Hakiel, Michael; Jacobs, Stephen D.

2003-05-01

Deterministic microgrinding (DMG) of optical glasses and ceramics is the commercial manufacturing process of choice to shape glass surfaces prior to final finishing. This process employs rigid bound matrix diamond tooling resulting in surface roughness values of 3-5μm peak to valley and 100-400nm rms, as well as mid-spatial frequency tool marks that require subsequent removal in secondary finishing steps. The ability to pre-polish optical surfaces within the grinding platform would reduce final finishing process times. Bound abrasive contour wheels containing cerium oxide, alumina or zirconia abrasives were constructed with an epoxy matrix. The effects of abrasive type, composition, and erosion promoters were examined for tool hardness (Shore D), and tested with commercial optical glasses in an Optipro CNC grinding platform. Metrology protocols were developed to examine tool wear and subsequent surface roughness. Work is directed to demonstrating effective material removal, improved surface roughness and cutter mark removal.

Catalytic multi-stage process for hydroconversion and refining hydrocarbon feeds

DOEpatents

Comolli, Alfred G.; Lee, Lap-Keung

2001-01-01

A multi-stage catalytic hydrogenation and hydroconversion process for heavy hydrocarbon feed materials such as coal, heavy petroleum fractions, and plastic waste materials. In the process, the feedstock is reacted in a first-stage, back-mixed catalytic reactor with a highly dispersed iron-based catalyst having a powder, gel or liquid form. The reactor effluent is pressure-reduced, vapors and light distillate fractions are removed overhead, and the heavier liquid fraction is fed to a second stage back-mixed catalytic reactor. The first and second stage catalytic reactors are operated at 700-850.degree. F. temperature, 1000-3500 psig hydrogen partial pressure and 20-80 lb./hr per ft.sup.3 reactor space velocity. The vapor and light distillates liquid fractions removed from both the first and second stage reactor effluent streams are combined and passed to an in-line, fixed-bed catalytic hydrotreater for heteroatom removal and for producing high quality naphtha and mid-distillate or a full-range distillate product. The remaining separator bottoms liquid fractions are distilled at successive atmospheric and vacuum pressures, low and intermediate-boiling hydrocarbon liquid products are withdrawn, and heavier distillate fractions are recycled and further upgraded to provide additional low-boiling hydrocarbon liquid products. This catalytic multistage hydrogenation process provides improved flexibility for hydroprocessing the various carbonaceous feedstocks and adjusting to desired product structures and for improved economy of operations.

UltraForm Finishing (UFF) a 5-axis computer controlled precision optical component grinding and polishing system

NASA Astrophysics Data System (ADS)

Bechtold, Michael; Mohring, David; Fess, Edward

2007-05-01

OptiPro Systems has developed a new finishing process for the manufacturing of precision optical components. UltraForm Finishing (UFF) has evolved from a tire shaped tool with polishing material on its periphery, to its newest design, which incorporates a precision rubber wheel wrapped with a band of polishing material passing over it. Through our research we have developed a user friendly graphical interface giving the optician a deterministic path for finishing precision optical components. Complex UFF Algorithms combine the removal function and desired depth of removal into a motion controlled tool path which minimizes surface roughness and form errors. The UFF process includes 5 axes of computer controlled motion, (3 linear and 2 rotary) which provide the flexibility for finishing a variety of shapes including spheres, aspheres, and freeform optics. The long arm extension, along with a range of diameters for the "UltraWheel" provides a unique solution for the finishing of steep concave shapes such as ogives and domes. The UltraForm process utilizes, fixed and loose abrasives, in combination with our proprietary "UltraBelts" made of a range of materials such as polyurethane, felt, resin, diamond and others.

Modifying the Interface Edge to Control the Electrical Transport Properties of Nanocontacts to Nanowires.

PubMed

Lord, Alex M; Ramasse, Quentin M; Kepaptsoglou, Despoina M; Evans, Jonathan E; Davies, Philip R; Ward, Michael B; Wilks, Steve P

2017-02-08

Selecting the electrical properties of nanomaterials is essential if their potential as manufacturable devices is to be reached. Here, we show that the addition or removal of native semiconductor material at the edge of a nanocontact can be used to determine the electrical transport properties of metal-nanowire interfaces. While the transport properties of as-grown Au nanocatalyst contacts to semiconductor nanowires are well-studied, there are few techniques that have been explored to modify the electrical behavior. In this work, we use an iterative analytical process that directly correlates multiprobe transport measurements with subsequent aberration-corrected scanning transmission electron microscopy to study the effects of chemical processes that create structural changes at the contact interface edge. A strong metal-support interaction that encapsulates the Au nanocontacts over time, adding ZnO material to the edge region, gives rise to ohmic transport behavior due to the enhanced quantum-mechanical tunneling path. Removal of the extraneous material at the Au-nanowire interface eliminates the edge-tunneling path, producing a range of transport behavior that is dependent on the final interface quality. These results demonstrate chemically driven processes that can be factored into nanowire-device design to select the final properties.

SULPHUR DIOXIDE LEACHING OF URANIUM CONTAINING MATERIAL

DOEpatents

Thunaes, A.; Rabbits, F.T.; Hester, K.D.; Smith, H.W.

1958-12-01

A process is described for extracting uranlum from uranium containing material, such as a low grade pitchblende ore, or mill taillngs, where at least part of the uraniunn is in the +4 oxidation state. After comminuting and magnetically removing any entrained lron particles the general material is made up as an aqueous slurry containing added ferric and manganese salts and treated with sulfur dioxide and aeration to an extent sufficient to form a proportion of oxysulfur acids to give a pH of about 1 to 2 but insufficient to cause excessive removal of the sulfur dioxide gas. After separating from the solids, the leach solution is adjusted to a pH of about 1.25, then treated with metallic iron in the presence of a precipitant such as a soluble phosphate, arsonate, or fluoride.

Plutonium recovery from organic materials

DOEpatents

Deaton, R.L.; Silver, G.L.

1973-12-11

A method is described for removing plutonium or the like from organic material wherein the organic material is leached with a solution containing a strong reducing agent such as titanium (III) (Ti/sup +3None)/, chromium (II) (Cr/ sup +2/), vanadium (II) (V/sup +2/) ions, or ferrous ethylenediaminetetraacetate (EDTA), the leaching yielding a plutonium-containing solution that is further processed to recover plutonium. The leach solution may also contain citrate or tartrate ion. (Official Gazette)

Near-Zero Emissions Oxy-Combustion Flue Gas Purification Task 3: SOx/NOx/Hg Removal for Low Sulfur Coal

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

Zanfir, Monica; Solunke, Rahul; Shah, Minish

2012-06-01

The goal of this project was to develop a near-zero emissions flue gas purification technology for existing PC (pulverized coal) power plants that are retrofitted with oxycombustion technology. The objective of Task 3 of this project was to evaluate an alternative method of SOx, NOx and Hg removal from flue gas produced by burning low sulfur coal in oxy-combustion power plants. The goal of the program was to conduct an experimental investigation and to develop a novel process for simultaneously removal of SOx and NOx from power plants that would operate on low sulfur coal without the need for wet-FGDmore » & SCRs. A novel purification process operating at high pressures and ambient temperatures was developed. Activated carbon's catalytic and adsorbent capabilities are used to oxidize the sulfur and nitrous oxides to SO{sub 3} and NO{sub 2} species, which are adsorbed on the activated carbon and removed from the gas phase. Activated carbon is regenerated by water wash followed by drying. The development effort commenced with the screening of commercially available activated carbon materials for their capability to remove SO{sub 2}. A bench-unit operating in batch mode was constructed to conduct an experimental investigation of simultaneous SOx and NOx removal from a simulated oxyfuel flue gas mixture. Optimal operating conditions and the capacity of the activated carbon to remove the contaminants were identified. The process was able to achieve simultaneous SOx and NOx removal in a single step. The removal efficiencies were >99.9% for SOx and >98% for NOx. In the longevity tests performed on a batch unit, the retention capacity could be maintained at high level over 20 cycles. This process was able to effectively remove up to 4000 ppm SOx from the simulated feeds corresponding to oxyfuel flue gas from high sulfur coal plants. A dual bed continuous unit with five times the capacity of the batch unit was constructed to test continuous operation and longevity. Full-automation was implemented to enable continuous operation (24/7) with minimum operator supervision. Continuous run was carried out for 40 days. Very high SOx (>99.9%) and NOx (98%) removal efficiencies were also achieved in a continuous unit. However, the retention capacity of carbon beds for SOx and NOx was decreased from ~20 hours to ~10 hours over a 40 day period of operation, which was in contrast to the results obtained in a batch unit. These contradictory results indicate the need for optimization of adsorption-regeneration cycle to maintain long term activity of activated carbon material at a higher level and thus minimize the capital cost of the system. In summary, the activated carbon process exceeded performance targets for SOx and NOx removal efficiencies and it was found to be suitable for power plants burning both low and high sulfur coals. More efforts are needed to optimize the system performance.« less

Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

PubMed Central

Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

2015-01-01

This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions. PMID:26486449

Correlation of impression removal force with elastomeric impression material rigidity and hardness.

PubMed

Walker, Mary P; Alderman, Nick; Petrie, Cynthia S; Melander, Jennifer; McGuire, Jacob

2013-07-01

Difficult impression removal has been linked to high rigidity and hardness of elastomeric impression materials. In response to this concern, manufacturers have reformulated their materials to reduce rigidity and hardness to decrease removal difficulty; however, the relationship between impression removal and rigidity or hardness has not been evaluated. The purpose of this study was to determine if there is a positive correlation between impression removal difficulty and rigidity or hardness of current elastomeric impression materials. Light- and medium-body polyether (PE), vinylpolysiloxane (VPS), and hybrid vinyl polyether siloxane (VPES) impression materials were tested (n = 5 for each material/consistency/test method). Rigidity (elastic modulus) was measured via tensile testing of dumbbell-shaped specimens (Die C, ASTM D412). Shore A hardness was measured using disc specimens according to ASTM D2240-05 test specifications. Impressions were also made of a custom stainless steel model using a custom metal tray that could be attached to a universal tester to measure associated removal force. Within each impression material consistency, one-factor ANOVA and Tukey's post hoc analyses (α = 0.05) were used to compare rigidity, hardness, and removal force of the three types of impression materials. A Pearson's correlation (α = 0.05) was used to evaluate the association between impression removal force and rigidity or hardness. With medium-body materials, VPS exhibited significantly higher (p ≤ 0.05) rigidity and hardness than VPES or PE, while PE impressions required significantly higher (p ≤ 0.05) removal force than VPS or VPES impressions. With light-body materials, VPS again demonstrated significantly higher (p ≤ 0.05) hardness than VPES or PE, while the rigidity of the light-body materials did not significantly differ between materials (p > 0.05); however, just as with the medium-body materials, light-body PE impressions required significantly higher (p ≤ 0.05) removal force than VPS or VPES. Moreover, there was no positive correlation (p > 0.05) between impression removal force and rigidity or hardness with either medium- or light-body materials. The evidence suggests that high impression material rigidity and hardness are not predictors of impression removal difficulty. © 2013 by the American College of Prosthodontists.

Evaluation of the Effect of Silicone Contamination on Various Bond Systems and the Feasibility of Removing the Contamination

NASA Technical Reports Server (NTRS)

Stanley, Stephanie D.

2008-01-01

Silicone is a contaminant that can cause catastrophic failure of a bond system depending on the materials and processes used to fabricate the bond system, Unfortunately, more and more materials are fabricated using silicone. The purpose of this testing was to evaluate which bond systems are sensitive to silicone contamination and whether or not a cleaning process could be utilized to remove the silicone to bring the bond system performance back to baseline. Due to the extensive nature of the testing attempts will be made to generalize the understanding within classes of substrates, bond systems, and surface preparation and cleaning methods. This study was done by contaminating various meta! (steel, inconel, and aluminum), phenolic (carbon cloth phenolic and glass cloth phenolic), and rubber (natural rubber, asbestos-silicone dioxide filled natural butyldiene rubber, silica-filled ethylene propylenediene monomer, and carbon-filled ethylene propylenediene monomer) substrates which were then bonded using various adhesives and coatings (epoxy-based adhesives, paints, ablative compounds, and Chemlok adhesives) to determine the effect silicone contamination has on a given bond system's performance. The test configurations depended on the bond system being evaluated. The study also evaluated the feasibility of removing the silicone contamination by cleaning the contaminated substrate prior to bonding. The cleaning processes also varied depending on bond system.

Molecular sieving silica membrane fabrication process

DOEpatents

Raman, Narayan K.; Brinker, Charles Jeffrey

1998-01-01

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Molecular sieving silica membrane fabrication process

DOEpatents

Raman, Narayan K.; Brinker, Charles Jeffrey

1999-01-01

A process for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film.

Advancements in Binder Systems for Solid Freeform Fabrication

NASA Technical Reports Server (NTRS)

Cooper, Ken; Munafo, Paul (Technical Monitor)

2002-01-01

Paper will present recent developments in advanced material binder systems for solid freeform fabrication (SFF) technologies. The advantage of SFF is the capability to custom fabricate complex geometries directly from computer aided design data in layer- by-layer fashion, eliminated the need for traditional fixturing and tooling. Binders allow for the low temperature processing of 'green' structural materials, either metal, ceramic or composite, in traditional rapid prototyping machines. The greatest obstacle comes when green parts must then go through a sintering or burnout process to remove the binders and fully densify the parent material, without damaging or distorting the original part geometry. Critical issues and up-to-date assessments will be delivered on various material systems.

[Factors affecting biological removal of iron and manganese in groundwater].

PubMed

Xue, Gang; He, Sheng-Bing; Wang, Xin-Ze

2006-01-01

Factors affecting biological process for removing iron and manganese in groundwater were analyzed. When DO and pH in groundwater after aeration were 7.0 - 7.5 mg/L and 6.8 - 7.0 respectively, not only can the activation of Mn2+ oxidizing bacteria be maintained, but also the demand of iron and manganese removal can be satisfied. A novel inoculating approach of grafting mature filter material into filter bed, which is easier to handle than selective culture media, was employed in this research. However, this approach was only suitable to the filter material of high-quality manganese sand with strong Mn2+ adsorption capacity. For the filter material of quartz sand with weak adsorption capacity, only culturing and domesticating Mn2+ oxidizing bacteria by selective culture media can be adopted as inoculation in filter bed. The optimal backwashing rate of biological filter bed filled with manganese sand and quartz sand should be kept at a relatively low level of 6 - 9 L/(m2 x s) and 7 -11 L/( m2 x s), respectively. Then the stability of microbial phase in filter bed was not disturbed, and iron and manganese removal efficiency recovered in less than 5h. Moreover, by using filter material with uniform particle size of 1.0 - 1.2 mm in filter bed, the filtration cycle reached as long as 35 - 38h.

Quantitative assessment of the enamel machinability in tooth preparation with dental diamond burs.

PubMed

Song, Xiao-Fei; Jin, Chen-Xin; Yin, Ling

2015-01-01

Enamel cutting using dental handpieces is a critical process in tooth preparation for dental restorations and treatment but the machinability of enamel is poorly understood. This paper reports on the first quantitative assessment of the enamel machinability using computer-assisted numerical control, high-speed data acquisition, and force sensing systems. The enamel machinability in terms of cutting forces, force ratio, cutting torque, cutting speed and specific cutting energy were characterized in relation to enamel surface orientation, specific material removal rate and diamond bur grit size. The results show that enamel surface orientation, specific material removal rate and diamond bur grit size critically affected the enamel cutting capability. Cutting buccal/lingual surfaces resulted in significantly higher tangential and normal forces, torques and specific energy (p<0.05) but lower cutting speeds than occlusal surfaces (p<0.05). Increasing material removal rate for high cutting efficiencies using coarse burs yielded remarkable rises in cutting forces and torque (p<0.05) but significant reductions in cutting speed and specific cutting energy (p<0.05). In particular, great variations in cutting forces, torques and specific energy were observed at the specific material removal rate of 3mm(3)/min/mm using coarse burs, indicating the cutting limit. This work provides fundamental data and the scientific understanding of the enamel machinability for clinical dental practice. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of tools geometry and processing conditions on behavior of a difficult-to-work Al-Mg alloy during equal channel angular pressing

NASA Astrophysics Data System (ADS)

Comǎneci, Radu Ioachim; Nedelcu, Dumitru; Bujoreanu, Leandru Gheorghe

2017-10-01

Equal channel angular pressing (ECAP) is a well-established method for grain refinement in metallic materials by large shear plastic deformation, being the most promising and effective severe plastic deformation (SPD) technique. ECAP is a discontinuous process, so the billet removal implies a new development of the procedure: the new sample pushes out the previous sample. In resuming the process the head and the tail ends of the work piece which becomes strongly distorted and receiving different amount of strain have to be removed. Due to the path difference in material flow between upper and lower region of the outlet channel, a non-uniform strain and stress distribution across the width of the workpiece leaving the plastic deformation zone (PDZ) is achieved. A successful ECAP requires surpassing two obstacles: the necessary load level which directly affects tools and a favorable stress distribution so the material withstanding the accumulated strain of repeated deformation. Under back pressure (BP), materials have shown to be able to withstand more passes. As soon as the billet passes the PDZ along the bisector plane of the two channels, the compressive mean stress changes to tensile (leading to crack initiation), while in the presence of BP, a negative (compressive) stress is applied during the process. In this paper a comparative tridimensional finite element analysis (FEA) is performed to evaluate the behavior of a difficult-to-work Al-Mg alloy depending on tools geometry and process parameters. The results in terms of load level and strain distribution show the influence of the punch geometry and BP on the material behavior.

Failure Analysis of Cracked FS-85 Tubing and ASTAR-811C End Caps

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

ME Petrichek

2006-02-09

Failure analyses were performed on cracked FS-85 tubing and ASTAR-811C and caps which had been fabricated as components of biaxial creep specimens meant to support materials testing for the NR Space program. During the failure analyses of cracked FS-85 tubing, it was determined that the failure potentially could be due to two effects: possible copper contamination from the EDM (electro-discharge machined) recast layer and/or an insufficient solution anneal. to prevent similar failures in the future, a more formal analysis should be done after each processing step to ensure the quality of the material before further processing. During machining of themore » ASTAR-811FC rod to form end caps for biaxial creep specimens, linear defects were observed along the center portion of the end caps. These defects were only found in material that was processed from the top portion of the ingot. The linear defects were attributed to a probable residual ingot pipe that was not removed from the ingot. During the subsequent processing of the ingot to rod, the processing temperatures were not high enough to allow self healing of the ingot's residual pipe defect. To prevent this from occurring in the future, it is necessary to ensure that complete removal of the as-melted ingot pipe is verified by suitable non-destructive evaluation (NDE).« less

POTENTIAL IMPACT OF BLENDING RESIDUAL SOLIDS FROM TANKS 18/19 MOUNDS WITH TANK 7 OPERATIONS

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

Eibling, R; Erich Hansen, E; Bradley Pickenheim, B

2007-03-29

High level waste tanks 18F and 19F have residual mounds of waste which may require removal before the tanks can be closed. Conventional slurry pump technology, previously used for waste removal and tank cleaning, has been incapable of removing theses mounds from tanks 18F and 19F. A mechanical cleaning method has been identified that is potentially capable of removing and transferring the mound material to tank 7F for incorporation in a sludge batch for eventual disposal in high level waste glass by the Defense Waste Processing Facility. The Savannah River National Laboratory has been requested to evaluate whether the materialmore » transferred from tanks 18F/19F by the mechanical cleaning technology can later be suspended in Tank 7F by conventional slurry pumps after mixing with high level waste sludge. The proposed mechanical cleaning process for removing the waste mounds from tanks 18 and 19 may utilize a high pressure water jet-eductor that creates a vacuum to mobilize solids. The high pressure jet is also used to transport the suspended solids. The jet-eductor system will be mounted on a mechanical crawler for movement around the bottom of tanks 18 and 19. Based on physical chemical property testing of the jet-eductor system processed IE-95 zeolite and size-reduced IE-95 zeolite, the following conclusions were made: (1) The jet-eductor system processed zeolite has a mean and median particle size (volume basis) of 115.4 and 43.3 microns in water. Preferential settling of these large particles is likely. (2) The jet-eductor system processed zeolite rapidly generates settled solid yield stresses in excess of 11,000 Pascals in caustic supernates and will not be easily retrieved from Tank 7 with the existing slurry pump technology. (3) Settled size-reduced IE-95 zeolite (less than 38 microns) in caustic supernate does not generate yield stresses in excess of 600 Pascals in less than 30 days. (4) Preferential settling of size-reduced zeolite is a function of the amount of sludge and the level of dilution for the mixture. (5) Blending the size-reduced zeolite into larger quantities of sludge can reduce the amount of preferential settling. (6) Periodic dilution or resuspension due to sludge washing or other mixing requirements will increase the chances of preferential settling of the zeolite solids. (7) Mixtures of Purex sludge and size-reduced zeolite did not produce yield stresses greater than 200 Pascals for settling times less than thirty days. Most of the sludge-zeolite blends did not exceed 50 Pascals. These mixtures should be removable by current pump technology if sufficient velocities can be obtained. (8) The settling rate of the sludge-zeolite mixtures is a function of the ionic strength (or supernate density) and the zeolite- sludge mixing ratio. (9) Simulant tests indicate that leaching of Si may be an issue for the processed Tank 19 mound material. (10) Floating zeolite fines observed in water for the jet-eductor system and size-reduced zeolite were not observed when the size-reduced zeolite was blended with caustic solutions, indicating that the caustic solutions cause the fines to agglomerate. Based on the test programs described in this report, the potential for successfully removing Tank 18/19 mound material from Tank 7 with the current slurry pump technology requires the reduction of the particle size of the Tank 18/19 mound material.« less

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%).

Development and testing of a wet oxidation waste processing system. [for waste treatment aboard manned spacecraft

NASA Technical Reports Server (NTRS)

Weitzmann, A. L.

1977-01-01

The wet oxidation process is considered as a potential treatment method for wastes aboard manned spacecraft for these reasons: (1) Fecal and urine wastes are processed to sterile water and CO2 gas. However, the water requires post-treatment to remove salts and odor; (2) the residual ash is negligible in quantity, sterile and easily collected; and (3) the product CO2 gas can be processed through a reduction step to aid in material balance if needed. Reaction of waste materials with oxygen at elevated temperature and pressure also produces some nitrous oxide, as well as trace amounts of a few other gases.

Polishing of silicon based advanced ceramics

NASA Astrophysics Data System (ADS)

Klocke, Fritz; Dambon, Olaf; Zunke, Richard; Waechter, D.

2009-05-01

Silicon based advanced ceramics show advantages in comparison to other materials due to their extreme hardness, wear and creep resistance, low density and low coefficient of thermal expansion. As a matter of course, machining requires high efforts. In order to reach demanded low roughness for optical or tribological applications a defect free surface is indispensable. In this paper, polishing of silicon nitride and silicon carbide is investigated. The objective is to elaborate scientific understanding of the process interactions. Based on this knowledge, the optimization of removal rate, surface quality and form accuracy can be realized. For this purpose, fundamental investigations of polishing silicon based ceramics are undertaken and evaluated. Former scientific publications discuss removal mechanisms and wear behavior, but the scientific insight is mainly based on investigations in grinding and lapping. The removal mechanisms in polishing are not fully understood due to complexity of interactions. The role of, e.g., process parameters, slurry and abrasives, and their influence on the output parameters is still uncertain. Extensive technological investigations demonstrate the influence of the polishing system and the machining parameters on the stability and the reproducibility. It is shown that the interactions between the advanced ceramics and the polishing systems is of great relevance. Depending on the kind of slurry and polishing agent the material removal mechanisms differ. The observed effects can be explained by dominating mechanical or chemo-mechanical removal mechanisms. Therefore, hypotheses to state adequate explanations are presented and validated by advanced metrology devices, such as SEM, AFM and TEM.

Study on contaminants on flight and other critical surfaces

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Hughes, Charles; Arendale, William F.

1994-01-01

The control of surface contamination in the manufacture of space hardware can become a critical step in the production process. Bonded surfaces have been shown to be affected markedly by contamination. It is important to insure surface cleanliness by preventing contamination prior to bonding. In this vein techniques are needed in which the contamination which may affect bonding are easily found and removed. Likewise, if materials which are detrimental to bonding are not easily removed, then they should not be used in the manufacturing process. This study will address the development of techniques to locate and quantify contamination levels of particular contaminants. With other data becoming available from MSFC and its contractors, this study will also quantify how certain contaminants affect bondlines and how easily they are removed in manufacturing.

The electrical discharge machining of ceramics

NASA Astrophysics Data System (ADS)

Trueman, Christopher Stuart

This study introduces the concept of developing a novel and rapid rough-machining methodology for spark eroding suitable ceramic compositions based on material removal by thermal shock induced spalling, as opposed to conventional melting mechanisms. The principal materials studied were TiB2 dispersion toughened SiC, and Syalon501 - a commercially available TiN toughened sialon ceramic specifically designed for spark erosion. A preliminary study was also carried out on a range of SiC:B4C composites. Machinability and material performance were assessed where appropriate using machining parameters, material removal rate tests, surface analysis, four-point flexure testing, and tool wear. The machining technologies which supported the different mechanisms of material removal were identified, and each mechanism investigated by analysis of captured debris and sectioning of the workpiece. The SiC:B4C composites were found to be spark erodible only with B4C levels above 50% (by mass), and material removal was found to be solely by melting mechanisms. A SiC:TiB2 composition with the addition of 26.5% TiB2 (by mass) was found to be more machinable than a composition with 10% TiB2 (by mass), achieving greater material removal rates owing to its higher electrical conductivity. An in-depth study of the latter (10%TiB2) SiC composition and Syalon501 revealed surprisingly robust materials. Under conventional sparking (no arcing), material was removed by combined dissociation, melting and evaporation. Syalon501 in particular behaved with a high degree of predictability, and neither material could be made to spall under conventional sparking. However, by imposing conditions which deliberately induced arcing, both compositions spalled large flakes of material (up to several hundred microns across) in the localised region of the arc-strike. Examination of captured debris and fracture facets of the spall interface revealed the existence of small "penny cracks", each characterised by the presence of a dispersed particle (of greater thermal expansion) at its centre acting as a stress- raising nucleation point under the intense thermal loading of arcing. Sub-surface cracks in the near horizontal and near-vertical planes were discovered in line with published models based on the application of a hot-spot to brittle material, and evidence of discrete crack propagation under the thermally punctuated pulses of successive sparking was identified. Similar sub-surface cracking was also confirmed in Syalon501 which had been subjected to arcing. Sectioning of the workpiece revealed shallow sub-surface cracks which followed the profile of the machined surface in the near-horizontal plane, and which often limited the extent of near-vertical cracking to the layer of material above the crack, thereby offering the potential for a reliable and fast "planning" technique in which material would be removed in shallow layers. This research has shown that the possibility exists for increased material removal rates and improved process efficiency under a spalling-based machining regime, in which layers of material are released by thermal-shock induced fracture caused by arcing. The viability of developing a new rough-machining technology for ceramics, in which material is "planed" away prior to fine surface finishing by conventional spark erosion has, therefore, been successfully demonstrated.

APPARATUS FOR CONDENSATION AND SUBLIMATION

DOEpatents

Schmidt, R.J.; Fuis, F. Jr.

1958-10-01

An apparatus is presented for the sublimation and condensation of uranium compounds in order to obtain an improved crystalline structure of this material. The apparatus comprises a vaporizing chamber and condensing structure connected thereto. There condenser is fitted with a removable liner having a demountable baffle attached to the liner by means of brackets and a removable pin. The baffle is of spiral cross-section and is provided with cooling coils disposed between the surfaces of the baffle for circulation of a temperature controlling liquid within the baffle. The cooling coll provides for controlllng the temperature of the baffle to insure formatlon of a satisfactory condensate, and the removable liner facilitates the removal of condensate formed during tbe sublimation process.

3D Printing: Downstream Production Transforming the Supply Chain

DTIC Science & Technology

2017-01-01

generative designs , and tailorable material properties will transform the way both military and civilian products are manufactured —from simple objects... design . Traditional and established subtractive manufacturing (SM) creates objects by removing material (e.g., through drilling or lathing) from solid... manufacturers to build products with highly complex geometry in a single process rather than by combining multiple components manufactured by

AM2 Mat End Connector Modeling and Performance Validation

DTIC Science & Technology

2015-08-01

9 3.2.1 Subgrade construction and posttest forensics...layout. 3.2.1 Subgrade construction and posttest forensics The test section subgrade was built using in-place material from a previous AM2 test...area 50 ft wide by 42 ft long of the existing test bed was removed and replaced with newly processed material. Posttest values from the previous

Exploring the uses for small-diameter trees

Treesearch

Susan L. LeVan-Green; Jean. Livingston

2001-01-01

Small-diameter and underutilized (SDU) material refers to the timber that is left in the forest because it is not economical to remove, or local capacity to process it does not exist. SDU material also includes the dense, understory present through-out the forest as a result of 50 years of successful fire suppression. It has become apparent that there are many...

BAG PASSOUT SEALER FOR WATER-SHIELDED CAVE FACILITY (Engineering Materials)

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

None

1963-10-31

The water-shielded cave facility is used in processing irradiated slugs for recovery of americium, curium, berkelium, californium, einsteinium, and fermium. The remotely operated, plastic-bag passout sealer is used in removing isotopic fractions for storage in the rear or for removing radioactive waste for placement in the waste storage containers. The unit is accessible by both the primary inclosure master-slaves and the service area master-slaves. (F.L.S.)

Processing waste fats into a fuel oil substitute

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

Pudel, F.; Lengenfeld, P.

1993-12-31

Waste fats have a high energy potential. They also contain impurities. For example, fats used for deep-frying contain high contents of solids, water, and chlorides. The process described in this paper removes the impurities by simple processing such as screening, washing, separating, drying, and filtering. The final quality of processed fat allows its use as a fuel oil substitute, and also as a raw material for chemical production.

TiO2/porous adsorbents: Recent advances and novel applications.

PubMed

MiarAlipour, Shayan; Friedmann, Donia; Scott, Jason; Amal, Rose

2018-01-05

This article reviews two interrelated areas of research: the first is the use of TiO 2 -supported adsorbent materials as enhanced heterogeneous photocatalysts and their application to various reactions for organic pollutant removal from air and water; the second is the combination of adsorbent materials with TiO 2 photocatalysts which aims to efficiently regenerate adsorbent materials using illumination. By reviewing both areas of research, the following topics are covered; (i) photocatalytic activation of TiO 2; (ii) related properties of photocatalytic TiO 2; (iii) shortcomings of photocatalytic processes; (iv) preparation methods of composite TiO 2 /adsorbent materials and their photocatalytic performance; (v) properties of common adsorbents and their applications for pollutant removal from air and water; (vi) adsorbent regeneration methods and their economic and operational issues; (vii) conclusions and future outlooks. This topic has not been previously reviewed to such an extent, and considerable knowledge can be gained from assembling the large number of studies on adsorption-photocatalysis combinations. As such, this review provides guidance for researchers working in the fields of environmental and chemical engineering focussing on organic pollutant removal and the engineering of new high performance photocatalytic TiO 2 -supported porous adsorbent materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Using recycled concrete in MDOT's transportation infrastructure : manual of practice.

DOT National Transportation Integrated Search

2011-08-01

"Crushed concrete aggregate (CCA) is granular material manufactured by removing, crushing, and : processing old concrete for reuse as an aggregate source in new construction. Although the Michigan : Department of Transportation (MDOT) has used CCA si...

Nitrogen reactive ion etch processes for the selective removal of poly-(4-vinylpyridine) in block copolymer films.

PubMed

Flynn, Shauna P; Bogan, Justin; Lundy, Ross; Khalafalla, Khalafalla E; Shaw, Matthew; Rodriguez, Brian J; Swift, Paul; Daniels, Stephen; O'Connor, Robert; Hughes, Greg; Kelleher, Susan M

2018-08-31

Self-assembling block copolymer (BCP) patterns are one of the main contenders for the fabrication of nanopattern templates in next generation lithography technology. Transforming these templates to hard mark materials is key for pattern transfer and in some cases, involves selectively removing one block from the nanopattern. For poly(styrene)-block-poly(4-vinylpyridine) (PS-b-P4VP), a high χ BCP system which could be potentially incorporated into semiconductor nanofabrication, this selective removal is predominantly done by a wet etch/activation process. Conversely, this process has numerous disadvantages including lack of control and high generation of waste leading to high cost. For these reasons, our motivation was to move away from the wet etch process and optimise a dry etch which would overcome the limitations associated with the activation process. The work presented herein shows the development of a selective plasma etch process for the removal of P4VP cores from PS-b-P4VP nanopatterned film. Results have shown that a nitrogen reactive ion etch plasma has a selectivity for P4VP of 2.2:1 and suggest that the position of the nitrogen in the aromatic ring of P4VP plays a key role in this selectivity. In situ plasma etching and x-ray photoelectron spectrometry measurements were made without breaking vacuum, confirming that the nitrogen plasma has selectivity for removal of P4VP over PS.

A Pontential Agriculture Waste Material as Coagulant Aid: Cassava Peel

NASA Astrophysics Data System (ADS)

Othman, N.; Abd-Rahim, N.-S.; Tuan-Besar, S.-N.-F.; Mohd-Asharuddin, S.; Kumar, V.

2018-02-01

All A large amount of cassava peel waste is generated annually by small and medium scale industries. This has led to a new policy of complete utilization of raw materials so that there will be little or no residue left that could pose pollution problems. Conversion of these by-products into a material that poses an ability to remove toxic pollutant would increase the market value and ultimately benefits the producers. This study investigated the characteristics of cassava peel as a coagulant aid material and optimization process using the cassava peel was explored through coagulation and flocculation. This research had highlighted that the Cassava peels contain sugars in the form of polysaccharides such as starch and holocellulose. The FTIR results revealed that amino acids containing abundant of carboxyl, hydroxyl and amino groups which has significant capabilities in removing pollutants. Whereas analysis by XRF spectrometry indicated that the CP samples contain Fe2O3 and Al2O3 which might contribute to its coagulation ability. The optimum condition allowed Cassava peel and alum removed high turbidity up to 90. This natural coagulant from cassava peel is found to be an alternative coagulant aid to reduce the usage of chemical coagulants

A Study of Testing Different Mandrels for Electroforming Nickel

NASA Astrophysics Data System (ADS)

Murrell, Alex D. G.

Material failure is a prevalent problem in all engineering industries, particularly aerospace and automotive. The demand high-performance materials is higher than ever. Nickel is a metal that is favoured greatly because of its ability to withstand harsh operating conditions such as corrosive environments and extreme temperatures. Nickel parts can be produced by electroforming, a unique process that requires a removable conductive mandrel. An electroplating apparatus was set up at Tennessee Technological University to deposit nickel onto these mandrels where different methods of removal would be explored. Various different mandrels - conductive and non-conductive - were tested by nickel electroplating in a Watts nickel bath to establish a firm testing procedure. The nickel coatings were retrieved where possible and were analysed with appropriate methods. It was found that tin was the best material to use for a substrate through performance ranking, and a conductive polycarbonate was the worst material choice for a substrate. The substrates that demonstrated the easiest method of removal were tin and wax. Different methods of increasing - and also inhibiting - conductivity were applied to various substrates, where it was found that the use of a conductive graphite paint was particularly beneficial to the plating potential of a substrate.

Optimization of outgassing bake-out temperatures and duration of space systems

NASA Technical Reports Server (NTRS)

Scialdone, J. J.

1986-01-01

Satellite components, e.g., solar panels, were subjected to bake-out tests to model outgassing characteristics and to identify methods for minimizing the bake-out time. Bake-out removes gases and particulates that are trapped at the surfaces of components during manufacture, storage, transit and handling. The tests covered temperatures from 45-85 C for up to 200 hr. Measurements of the mass loss rates were used to model the process as a function of the temperature, time and mass. Data sampling with a quartz crystal microbalance was found to be an effective means for ascertaining the mass loss rate and the activation energy of the release. The tests showed that the duration of the bake-out depends on the amount of material which must be removed and the type of outgassing which occurs. Materials which are resistant to high temperatures can be baked at the highest feasible temperatures to accelerate the outgassing process.

Adsorption of Safranin-T from wastewater using waste materials- activated carbon and activated rice husks.

PubMed

Gupta, Vinod K; Mittal, Alok; Jain, Rajeev; Mathur, Megha; Sikarwar, Shalini

2006-11-01

Textile effluents are major industrial polluters because of high color content, about 15% unfixed dyes and salts. The present paper is aimed to investigate and develop cheap adsorption methods for color removal from wastewater using waste materials activated carbon and activated rice husk-as adsorbents. The method was employed for the removal of Safranin-T and the influence of various factors such as adsorbent dose, adsorbate concentration, particle size, temperature, contact time, and pH was studied. The adsorption of the dye over both the adsorbents was found to follow Langmuir and Freundlich adsorption isotherm models. Based on these models, different useful thermodynamic parameters have been evaluated for both the adsorption processes. The adsorption of Safranin-T over activated carbon and activated rice husks follows first-order kinetics and the rate constants for the adsorption processes decrease with increase in temperature.

Femtopulse laser-based mask repair in the DUV wavelength regime

NASA Astrophysics Data System (ADS)

Ghadiali, Firoz; Tolani, Vikram; Nagpal, Rajesh; Robinson, Tod; LeClaire, Jeff; Bozak, Ron; Lee, David A.; White, Roy

2006-05-01

Deep ultraviolet (DUV) femtosecond-pulsed laser ablation has numerous highly desirable properties for subtractive photomask defect repair. These qualities include high removal rates, resolution better than the focused spot size, minimized redeposition of the ablated material (rollup and splatter), and a negligible heat affected zone. The optical properties of the photomask result in a broad repair process window because the absorber film (whether Cr or MoSi) and the transmissive substrate allow for a high degree of material removal selectivity. Repair results and process parameters from such a system are examined in light of theoretical considerations. In addition, the practical aspects of the operation of this system in a production mask house environment are reviewed from the standpoint of repair quality, capability, availability, and throughput. Focus is given to the benefit received by the mask shop, and to the technical performance of the system.

Synthesis of the thermoelectric nanopowder recovered from the used thermoelectric modules.

PubMed

Lee, Kun-Jae; Jin, Yun-Ho; Kong, Man-Sik

2014-10-01

We fabricated the thermoelectric powder using the used thermoelectric modules in a vehicle. As a starting material, the used thermoelectric modules were collected and separated to substrate, electrode, solder, and thermoelectric parts by a thermal process. The separation process was performed in a wet process at the critical temperature. The solder in the module was the neighbor part of the thermoelectric material with the lowest melting temperature in the module. We focused on the thermal property of the solder to separate the thermoelectric chips in the module. After the separation process, we prepared the pure thermoelectric material by the chemical etching for an impurity removal. Also the thermoelectric nanopowder was fabricated by a chemical reduction reaction using the recycled thermoelectric materials. The recovered nanopowder was confirmed to the phase of bismuth telluride (Bi2Te3) with the particle size of -15 nm.

Arsenite removal from aqueous solutions by γ-Fe2O3-TiO2 magnetic nanoparticles through simultaneous photocatalytic oxidation and adsorption.

PubMed

Yu, Lian; Peng, Xianjia; Ni, Fan; Li, Jin; Wang, Dongsheng; Luan, Zhaokun

2013-02-15

A novel Fe-Ti binary oxide magnetic nanoparticles which combined the photocatalytic oxidation property of TiO(2) and the high adsorption capacity and magnetic property of γ-Fe(2)O(3) have been synthesized using a coprecipitation and simultaneous oxidation method. The as-prepared samples were characterized by powder XRD, TEM, TG-DTA, VSM and BET methods. Photocatalytic oxidation of arsenite, the effect of solution pH values and initial As(III) concentration on arsenite removal were investigated in laboratory experiments. Batch experimental results showed that under UV light, As(III) can be efficiently oxidized to As(V) by dissolved O(2) in γ-Fe(2)O(3)-TiO(2) nanoparticle suspensions at various pH values. At the same time, As(V) was effectively removed by adsorption onto the surface of nanoparticles. The maximum removal capability of the nano-material for arsenite was 33.03 mg/g at pH 7.0. Among all the common coexisting ions investigated, phosphate was the greatest competitor with arsenic for adsorptive sites on the nano-material. Regeneration studies verified that the γ-Fe(2)O(3)-TiO(2) nanoparticles, which underwent five successive adsorption-desorption processes, still retained comparable catalysis and adsorption performance, indicating the excellent stability of the nanoparticles. The excellent photocatalytic oxidation performance and high uptake capability of the magnetic nano-material make it potentially attractive material for the removal of As(III) from water. Copyright © 2012 Elsevier B.V. All rights reserved.

The use of a novel bone allograft wash process to generate a biocompatible, mechanically stable and osteoinductive biological scaffold for use in bone tissue engineering.

PubMed

Smith, C A; Richardson, S M; Eagle, M J; Rooney, P; Board, T; Hoyland, J A

2015-05-01

Fresh-frozen biological allograft remains the most effective substitute for the 'gold standard' autograft, sharing many of its osteogenic properties but, conversely, lacking viable osteogenic cells. Tissue engineering offers the opportunity to improve the osseointegration of this material through the addition of mesenchymal stem cells (MSCs). However, the presence of dead, immunogenic and potentially harmful bone marrow could hinder cell adhesion and differentiation, graft augmentation and incorporation, and wash procedures are therefore being utilized to remove the marrow, thereby improving the material's safety. To this end, we assessed the efficiency of a novel wash technique to produce a biocompatible, biological scaffold void of cellular material that was mechanically stable and had osteoinductive potential. The outcomes of our investigations demonstrated the efficient removal of marrow components (~99.6%), resulting in a biocompatible material with conserved biomechanical stability. Additionally, the scaffold was able to induce osteogenic differentiation of MSCs, with increases in osteogenic gene expression observed following extended culture. This study demonstrates the efficiency of the novel wash process and the potential of the resultant biological material to serve as a scaffold in bone allograft tissue engineering. © 2014 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons Ltd.

Effect of UV curing time on physical and electrical properties and reliability of low dielectric constant materials

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

Kao, Kai-Chieh; Cheng, Yi-Lung, E-mail: yjcheng@ncnu.edu.tw; Chang, Wei-Yuan

2014-11-01

This study comprehensively investigates the effect of ultraviolet (UV) curing time on the physical, electrical, and reliability characteristics of porous low-k materials. Following UV irradiation for various periods, the depth profiles of the chemical composition in the low-k dielectrics were homogeneous. Initially, the UV curing process preferentially removed porogen-related CH{sub x} groups and then modified Si-CH{sub 3} and cage Si-O bonds to form network Si-O bonds. The lowest dielectric constant (k value) was thus obtained at a UV curing time of 300 s. Additionally, UV irradiation made porogen-based low-k materials hydrophobic and to an extent that increased with UV curing time.more » With a short curing time (<300 s), porogen was not completely removed and the residues degraded reliability performance. A long curing time (>300 s) was associated with improved mechanical strength, electrical performance, and reliability of the low-k materials, but none of these increased linearly with UV curing time. Therefore, UV curing is necessary, but the process time must be optimized for porous low-k materials on back-end of line integration in 45 nm or below technology nodes.« less

Coating carbon nanotubes with humic acid using an eco-friendly mechanochemical method: Application for Cu(II) ions removal from water and aquatic ecotoxicity.

PubMed

Côa, Francine; Strauss, Mathias; Clemente, Zaira; Rodrigues Neto, Laís L; Lopes, Josias R; Alencar, Rafael S; Souza Filho, Antônio G; Alves, Oswaldo L; Castro, Vera Lúcia S S; Barbieri, Edison; Martinez, Diego Stéfani T

2017-12-31

In this work, industrial grade multi-walled carbon nanotubes (MWCNT) were coated with humic acid (HA) for the first time by means of a milling process, which can be considered an eco-friendly mechanochemical method to prepare materials and composites. The HA-MWCNT hybrid material was characterized by atomic force microscopy (AFM), scanning electron microscopies (SEM and STEM), X-ray photoelectron spectroscopy (XPS), termogravimetric analysis (TGA), and Raman spectroscopy. STEM and AFM images demonstrated that the MWCNTs were efficiently coated by the humic acid, thus leading to an increase of 20% in the oxygen content at the nanotube surface as observed by the XPS data. After the milling process, the carbon nanotubes were shortened as unveiled by SEM images and the values of ID/IG intensity ratio increased due to shortening of the nanotubes and increasing in the number defects at the graphitic structure of carbon nanotubes walls. The analysis of TGA data showed that the quantity of the organic matter of HA on the nanotube surface was 25%. The HA coating was responsible to favor the dispersion of MWCNTs in ultrapure water (i.e. -42mV, zeta-potential value) and to improve their capacity for copper removal. HA-MWCNTs hybrid material adsorbed 2.5 times more Cu(II) ions than oxidized MWCNTs with HNO 3 , thus evidencing that it is a very efficient adsorbent material for removing copper ions from reconstituted water. The HA-MWCNTs hybrid material did not show acute ecotoxicity to the tested aquatic model organisms (Hydra attenuata, Daphnia magna, and Danio rerio embryos) up to the highest concentration evaluated (10mgL -1 ). The results allowed concluding that the mechanochemical method is effective to coat carbon nanotubes with humic acid, thus generating a functional hybrid material with low aquatic toxicity and great potential to be applied in environmental nanotechnologies such as the removal of heavy metal ions from water. Copyright © 2017 Elsevier B.V. All rights reserved.

Metal-organic framework templated synthesis of porous inorganic materials as novel sorbents

DOEpatents

Taylor-Pashow, Kathryn M. L.; Lin, Wenbin; Abney, Carter W.

2017-03-21

A novel metal-organic framework (MOF) templated process for the synthesis of highly porous inorganic sorbents for removing radionuclides, actinides, and heavy metals is disclosed. The highly porous nature of the MOFs leads to highly porous inorganic sorbents (such as oxides, phosphates, sulfides, etc) with accessible surface binding sites that are suitable for removing radionuclides from high level nuclear wastes, extracting uranium from acid mine drainage and seawater, and sequestering heavy metals from waste streams. In some cases, MOFs can be directly used for removing these metal ions as MOFs are converted to highly porous inorganic sorbents in situ.

Use of an Atmospheric Atomic Oxygen Beam for Restoration of Defaced Paintings

NASA Technical Reports Server (NTRS)

Banks, Bruce A.; Rutledge, Sharon K.; Karla, Margaret; Norris, Mary Jo; Real, William A.; Haytas, Christy A.

1999-01-01

An atmospheric atomic oxygen beam has been found to be effective in removing organic materials through oxidation that are typical of graffiti or other contaminant defacements which may occur to the surfaces of paintings. The technique, developed by the National Aeronautics and Space Administration, is portable and was successfully used at the Carnegie Museum of Art to remove a lipstick smudge from the surface of porous paint on the Andy Warhol painting "Bathtub." This process was also evaluated for suitability to remove felt tip and ball point ink graffiti from paper, gesso on canvas and cotton canvas.

Advanced material and approach for metal ions removal from aqueous solutions

PubMed Central

Turhanen, Petri A.; Vepsäläinen, Jouko J.; Peräniemi, Sirpa

2015-01-01

A Novel approach to remove metals from aqueous solutions has been developed. The method is based on a resin free, solid, non-toxic, microcrystalline bisphosphonate material, which has very low solubility in water (59 mg/l to ion free Milli-Q water and 13 mg/l to 3.5% NaCl solution). The material has been produced almost quantitatively on a 1 kg scale (it has been prepared also on a pilot scale, ca. 7 kg) and tested successfully for its ability to collect metal cations from different sources, such as ground water and mining process waters. Not only was this material highly efficient at collecting several metal ions out of solution it also proved to be regenerable and reusable over a number of adsorption/desorption, which is crucial for environmental friendliness. This material has several advantages compared to the currently used approaches, such as no need for any precipitation step. PMID:25758924

Enhanced biological phosphorus removal with different carbon sources.

PubMed

Shen, Nan; Zhou, Yan

2016-06-01

Enhanced biological phosphorus removal (EBPR) process is one of the most economical and sustainable methods for phosphorus removal from wastewater. However, the performance of EBPR can be affected by available carbon sources types in the wastewater that may induce different functional microbial communities in the process. Glycogen accumulating organisms (GAOs) and polyphosphate accumulating organisms (PAOs) are commonly found by coexisting in the EBPR process. Predominance of GAO population may lead to EBPR failure due to the competition on carbon source with PAO without contributing phosphorus removal. Carbon sources indeed play an important role in alteration of PAOs and GAOs in EBPR processes. Various types of carbon sources have been investigated for EBPR performance. Certain carbon sources tend to enrich specific groups of GAOs and/or PAOs. This review summarizes the types of carbon sources applied in EBPR systems and highlights the roles of these carbon sources in PAO and GAO competition. Both single (e.g., acetate, propionate, glucose, ethanol, and amino acid) and complex carbon sources (e.g., yeast extract, peptone, and mixed carbon sources) are discussed in this review. Meanwhile, the environmental friendly and economical carbon sources that are derived from waste materials, such as crude glycerol and wasted sludge, are also discussed and compared.

Advanced Water Purification System for In Situ Resource Utilization

NASA Technical Reports Server (NTRS)

Anthony, Stephen M.; Jolley, Scott T.; Captain, James G.

2013-01-01

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extraterrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtration material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removal technique. Our studies have shown a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Advanced Water Purification System for In Situ Resource Utilization Project

NASA Technical Reports Server (NTRS)

Anthony, Stephen M.

2014-01-01

A main goal in the field of In Situ Resource Utilization is to develop technologies that produce oxygen from regolith to provide consumables to an extratrrestrial outpost. The processes developed reduce metal oxides in the regolith to produce water, which is then electrolyzed to produce oxygen. Hydrochloric and hydrofluoric acids are byproducts of the reduction processes, which must be removed to meet electrolysis purity standards. We previously characterized Nation, a highly water selective polymeric proton-exchange membrane, as a filtrtion material to recover pure water from the contaminated solution. While the membranes successfully removed both acid contaminants, the removal efficiency of and water flow rate through the membranes were not sufficient to produce large volumes of electrolysis-grade water. In the present study, we investigated electrodialysis as a potential acid removable technique. Our studies have show a rapid and significant reduction in chloride and fluoride concentrations in the feed solution, while generating a relatively small volume of concentrated waste water. Electrodialysis has shown significant promise as the primary separation technique in ISRU water purification processes.

Mesophilic and thermophilic activated sludge post-treatment of paper mill process water.

PubMed

Vogelaar, J C T; Bouwhuis, E; Klapwijk, A; Spanjers, H; van Lier, J B

2002-04-01

Increasing system closure in paper mills and higher process water temperatures make the applicability of thermophilic treatment systems increasingly important. The use of activated sludge as a suitable thermophilic post-treatment system for anaerobically pre-treated paper process water from a paper mill using recycled wastepaper was studied. Two lab-scale plug flow activated sludge reactors were run in parallel for 6 months; a thermophilic reactor at 55 degrees C and a reference reactor at 30 degrees C. Both reactors were operated simultaneously at 20, 15 and 10 days SRT. The effects of temperature and SRT on sludge settleability and chemical oxygen demand (COD) removal efficiencies of different fractions were studied. Total COD removal percentages over the whole experimental period were 58+/-5% at 30 degrees C and 48 +/- 10% at 55 degrees C. The effect of the SRT on the total COD removal was negligible. Differences in total COD removal between both systems were due to a lesser removal of soluble and colloidal COD at 55 degrees C compared to the reference system. At 30 degrees C, colloidal COD removal percentages were 65+/-25%, 75+/-17% and 86+/-22% at 20, 15 and 10 days SRT, respectively. At 55 degrees C, these percentages were 48+/-34%, 40+/-28% and 70+/-25%, respectively. The effluent concentrations of colloidal COD in both systems were related to the influent concentration of colloidal material. The thermophilic sludge was not able to retain influent colloidal material as well as the mesophilic sludge causing a higher thermophilic effluent turbidity. Sludge settling properties were excellent in both reactor systems. These were neither temperature nor SRT dependent but were rather caused by extensive calcium precipitation in the aeration tanks creating a very dense sludge. For application in the board industry, a thermophilic in line treatment system seems feasible. The higher effluent turbidity is most likely offset by the energy gains of treatment under thermophilic conditions.

Experimental exploration of the hydrodynamic effect polishing machinability for different types of material

NASA Astrophysics Data System (ADS)

Peng, W. Q.; Li, Y.; Wang, Z.; Li, S. Y.

2018-01-01

Hydrodynamic effect polishing (HEP), in which the material removal relies on the chemisorption between nanoparticles and the workpiece surface in elastic mode, can realize automatic level smooth surface without surface/subsurface damage. The machinability of different types of optical material (such as monocrystalline silicon and crystalline quartz, amorphous silicate glass, Zerodur and so on) were investigated experimentally. The workpiece surfaces before and after being polished by HEP was observed by atomic force microscopy. The experimental results show the surface roughness of monocrystalline silicon and quartz, amorphous silicate glass have decreased from Rms 0.737nm to Rms 0.175nm, Rms 0.490nm to Rms 0.187nm, Rms 0.469nm to Rms 0.157nm respectively, and meanwhile all the defects and bumpy structures have been removed clearly. However the surface roughness has increased from Rms 0.213nm to Rms 0.321nm with the obvious increment of micro unevenness. By comparison, we can conclude that excellent performance is shown when HEP is applied on the optical material structure with a single monocrystalline or amorphous component. However the ultrasmooth surface cannot be obtained when HEP was applied on the combinational materials such as Zerodur glass. The micro unevenness increases gradually along with polishing process due to the different material removal of the monocrystalline and amorphous component.

Systems and methods for harvesting and storing materials produced in a nuclear reactor

DOEpatents

Heinold, Mark R.; Dayal, Yogeshwar; Brittingham, Martin W.

2016-04-05

Systems produce desired isotopes through irradiation in nuclear reactor instrumentation tubes and deposit the same in a robust facility for immediate shipping, handling, and/or consumption. Irradiation targets are inserted and removed through inaccessible areas without plant shutdown and placed in the harvesting facility, such as a plurality of sealable and shipping-safe casks and/or canisters. Systems may connect various structures in a sealed manner to avoid release of dangerous or unwanted matter throughout the nuclear plant, and/or systems may also automatically decontaminate materials to be released. Useable casks or canisters can include plural barriers for containment that are temporarily and selectively removable with specially-configured paths inserted therein. Penetrations in the facilities may limit waste or pneumatic gas escape and allow the same to be removed from the systems without over-pressurization or leakage. Methods include processing irradiation targets through such systems and securely delivering them in such harvesting facilities.

Computed tomography assessment of the efficiency of different techniques for removal of root canal filling material.

PubMed

Dall'Agnol, Cristina; Hartmann, Mateus Silveira Martins; Barletta, Fernando Branco

2008-01-01

This study evaluated the efficiency of different techniques for removal of filling material from root canals, using computed tomography (CT). Sixty mesial roots from extracted human mandibular molars were used. Root canals were filled and, after 6 months, the teeth were randomly assigned to 3 groups, according to the root-filling removal technique: Group A - hand instrumentation with K-type files; Group B - reciprocating instrumentation with engine-driven K-type files; and Group C rotary instrumentation with engine-driven ProTaper system. CT scans were used to assess the volume of filling material inside the root canals before and after the removal procedure. In both moments, the area of filling material was outlined by an experienced radiologist and the volume of filling material was automatically calculated by the CT software program. Based on the volume of initial and residual filling material of each specimen, the percentage of filling material removed from the root canals by the different techniques was calculated. Data were analyzed statistically by ANOVA and chi-square test for linear trend (?=0.05). No statistically significant difference (p=0.36) was found among the groups regarding the percent means of removed filling material. The analysis of the association between the percentage of filling material removal (high or low) and the proposed techniques by chi-square test showed statistically significant difference (p=0.015), as most cases in group B (reciprocating technique) presented less than 50% of filling material removed (low percent removal). In conclusion, none of the techniques evaluated in this study was effective in providing complete removal of filling material from the root canals.

Tungsten oxide--fly ash oxide composites in adsorption and photocatalysis.

PubMed

Visa, Maria; Bogatu, Cristina; Duta, Anca

2015-05-30

A novel composite based on tungsten oxide and fly ash was hydrothermally synthetized to be used as substrate in the advanced treatment of wastewaters with complex load resulted from the textile industry. The proposed treatment consists of one single step process combining photocatalysis and adsorption. The composite's crystalline structure was investigated by X-ray diffraction and FTIR, while atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to analyze the morphology. The adsorption capacity and photocatalytic properties of the material were tested on mono- and multi-pollutants systems containing two dyes (Bemacid Blau - BB and Bemacid Rot - BR) and one heavy metal ion-Cu(2+), and the optimized process conditions were identified. The results indicate better removal efficiencies using the novel composite material in the combined adsorption and photocatalysis, as compared to the separated processes. Dyes removal was significantly enhanced in the photocatalytic process by adding hydrogen peroxide and the mechanism was presented and discussed. The pseudo second order kinetics model best fitted the experimental data, both in the adsorption and in the combined processes. The kinetic parameters were calculated and correlated with the properties of the composite substrate. Copyright © 2015 Elsevier B.V. All rights reserved.

Pneumatic conveyance apparatus and process

DOEpatents

Heckendorn, Frank M.; Matzolf, Athneal D.; Hera, Kevin R.

2010-05-04

A pneumatic nozzle capable of removing dry solid debris, liquids, and mixtures of solid and liquid waste is provided. The pneumatic nozzle uses a pressurized gas stream to push materials through the nozzle. The force of a pressurized gas stream provides a partial vacuum to allow material to be introduced into an opening of a nozzle via a slight suction force. Thereafter, individual particles and materials introduced into the pneumatic nozzle are pushed by a stream of pressurized gas through the nozzle.

Microfluidic systems with embedded materials and structures and method thereof

DOEpatents

Morse, Jeffrey D [Martinez, CA; Rose, Klint A [Boston, MA; Maghribi, Mariam [Livermore, CA; Benett, William [Livermore, CA; Krulevitch, Peter [Pleasanton, CA; Hamilton, Julie [Tracy, CA; Graff, Robert T [Modesto, CA; Jankowski, Alan [Livermore, CA

2007-03-06

Described herein is a process for fabricating microfluidic systems with embedded components in which micron-scale features are molded into the polymeric material polydimethylsiloxane (PDMS). Micromachining is used to create a mold master and the liquid precursors for PDMS are poured over the mold and allowed to cure. The PDMS is then removed form the mold and bonded to another material such as PDMS, glass, or silicon after a simple surface preparation step to form sealed microchannels.

a Study on the Effect of Annealing Process on Sound Velocity and Internal Friction Using the Vibrating Reed Technique

NASA Astrophysics Data System (ADS)

Mukhopadhyay, P. K.; Kumar, Uday; Badawi, Emad

Al has unique intrinsic characteristics, which are of interest to scientists as well as engineers. Al and its alloys are slightly paramagnetic materials. Al has very low cross section for thermal neutrons of 0.23 barn, hence Al can be used in nuclear fields as a structural material which is virtually transparent to neutrons. We report VRT as a new technique to study material problems. We also discuss, the results of sound velocity and internal friction, and resonance frequency as a function of temperature range for a pure aluminum sample under investigation. By using VRT, we found that the annealing temperature (450°C) is sufficient to remove the type of defects introduced in the materials under study. The activation energy to remove point defect for Al samples was calculated and found to be about 0.0624 eV. Also, we could easily observe that Q-1 is a function of annealing time. From these measurements of sound velocity and internal friction we can conclude that VRT is a powerful tool for detecting and probing the physical properties of the material under study. Internal friction is a microscopic property for the indication of the purity of the sample. Sound velocity depends on the state of the materials (which depends on the process of treatment).

Compact 1.5-GHz intra-burst repetition rate Yb-doped all-PM-fiber laser system for ablation-cooled material removal

NASA Astrophysics Data System (ADS)

Akcaalan, Onder; Kalaycioglu, Hamit; Ilday, F. Omer

Although fs fiber laser systems are powerful technologies for material and tissue processing, limited ablation rates and high energy are drawbacks. Recently, we identified a new regime of laser-material interaction, ablation-cooled laser material removal, where the repetition rate has to be high enough so that the targeted spot size cannot cool down substantially by heat conduction which scales down ablation threshold by several orders of magnitude and reduces thermal effects to the bulk of the target. This opens the door to simplified laser systems for processing. In order to exploit this regime in tissue processing, a compact all-PM-fiber laser amplifier system with an intra-burst repetition rate of 1.5 GHz is developed on a 40 x 65 cm platform. The system is able to produce bursts ranging from 20-ns to 65-ns duration with 20 uJ to 80 uJ total energy, respectively, and pulses with up to 2 uJ individual energy and burst repetition rate ranging from 25 kHz to 200 kHz. The seed signal is generated by a home-built all-normal dispersion oscillator with 385 MHz repetition rate and converted to approximately 1.5 GHz by a multiplier. Amplified pulses are compressed to approximately 250-fs, the shortest pulse width for burst-mode fiber laser systems known to date.

Surface Damage and Treatment by Impact of a Low Temperature Nitrogen Jet

NASA Astrophysics Data System (ADS)

Laribou, Hicham; Fressengeas, Claude; Entemeyer, Denis; Jeanclaude, Véronique; Tazibt, Abdel

2011-01-01

Nitrogen jets under high pressure and low temperature have been introduced recently. The process consists in projecting onto a surface a low temperature jet obtained from releasing the liquid nitrogen stored in a high pressure tank (e.g. 3000 bars) through a nozzle. It can be used in a range of industrial applications, including surface treatment or material removal through cutting, drilling, striping and cleaning. The process does not generate waste other than the removed matter, and it only releases neutral gas into the atmosphere. This work is aimed at understanding the mechanisms of the interaction between the jet and the material surface. Depending on the impacted material, the thermo-mechanical shock and blast effect induced by the jet can activate a wide range of damage mechanisms, including cleavage, crack nucleation and spalling, as well as void expansion and localized ductile failure. The test parameters (standoff distance, dwell time, operating pressure) play a role in selecting the dominant damage mechanism, but combinations of these various modes are usually present. Surface treatment through phase transformation or grain fragmentation in a layer below the surface can also be obtained by adequate tuning of the process parameters. In the current study, work is undertaken to map the damage mechanisms in metallic materials as well as the influence of the test parameters on damage, along with measurements of the thermo-mechanical conditions (impact force, temperature) in the impacted area.

Strategy of Construction and Demolition Waste Management after Chemical Industry Facilities Removal

NASA Astrophysics Data System (ADS)

Tashkinova, I. N.; Batrakova, G. M.; Vaisman, Ya I.

2017-06-01

Mixed waste products are generated in the process of irrelevant industrial projects’ removal if conventional techniques of their demolition and dismantling are applied. In Russia the number of unused chemical industry facilities including structures with high rate of wear is growing. In removing industrial buildings and production shops it is used conventional techniques of demolition and dismantling in the process of which mixed waste products are generated. The presence of hazardous chemicals in these wastes makes difficulties for their use and leads to the increasing volume of unutilized residues. In the process of chemical industry facilities’ removal this fact takes on special significance as a high level of hazardous chemicals in the waste composition demands for the realization of unprofitable measures aimed at ensuring environmental and industrial safety. The proposed strategy of managing waste originated from the demolition and dismantling of chemical industry facilities is based on the methodology of industrial metabolism which allows identifying separate material flows of recycled, harmful and ballast components, performing separate collection of components during removal and taking necessary preventive measures. This strategy has been tested on the aniline synthesis plant being in the process of removal. As a result, a flow of 10 wt. %, subjected to decontamination, was isolated from the total volume of construction and demolition waste (C&D waste). The considered approach allowed using the resource potential of more than 80wt. % of waste and minimizing the disposed waste volume.

Fluid extraction

DOEpatents

Wai, Chien M.; Laintz, Kenneth E.

1999-01-01

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

Hard particle effect on surface generation in nano-cutting

NASA Astrophysics Data System (ADS)

Xu, Feifei; Fang, Fengzhou; Zhang, Xiaodong

2017-12-01

The influence of the hard particle on the surface generation, plastic deformation and processing forces in nano-cutting of aluminum is investigated by means of molecular dynamics simulations. In this investigation, a hard particle which is simplified as a diamond ball is embedded under the free surface of workpiece with different depths. The influence of the position of the hard ball on the surface generation and other material removal mechanism, such as the movement of the ball under the action of cutting tool edge, is revealed. The results show that when the hard particle is removed, only a small shallow pit is left on the machined surface. Otherwise, it is pressed down to the subsurface of the workpiece left larger and deeper pit on the generated surface. Besides that, the hard particle in the workpiece would increase the processing force when the cutting tool edge or the plastic carriers interact with the hard particle. It is helpful to optimize the cutting parameters and material properties for obtaining better surface quality in nano-cutting of composites or other materials with micro/nanoscale hard particles in it.

System for producing a uniform rubble bed for in situ processes

DOEpatents

Galloway, T.R.

1983-07-05

A method and a cutter are disclosed for producing a large cavity filled with a uniform bed of rubblized oil shale or other material, for in situ processing. A raise drill head has a hollow body with a generally circular base and sloping upper surface. A hollow shaft extends from the hollow body. Cutter teeth are mounted on the upper surface of the body and relatively small holes are formed in the body between the cutter teeth. Relatively large peripheral flutes around the body allow material to drop below the drill head. A pilot hole is drilled into the oil shale deposit. The pilot hole is reamed into a large diameter hole by means of a large diameter raise drill head or cutter to produce a cavity filled with rubble. A flushing fluid, such as air, is circulated through the pilot hole during the reaming operation to remove fines through the raise drill, thereby removing sufficient material to create sufficient void space, and allowing the larger particles to fill the cavity and provide a uniform bed of rubblized oil shale. 4 figs.

Removal of Cr(VI) from Water Using a New Reactive Material: Magnesium Oxide Supported Nanoscale Zero-Valent Iron

PubMed Central

Siciliano, Alessio

2016-01-01

The chromium pollution of water is an important environmental and health issue. Cr(VI) removal by means of metallic iron is an attractive method. Specifically, nanoscopic zero valent iron (NZVI) shows great reactivity, however, its applicability needs to be further investigated. In the present paper, NZVI was supported on MgO grains to facilitate the treatments for remediation of chromium-contaminated waters. The performances and mechanisms of the developed composite, in the removal of hexavalent chromium, were investigated by means of batch and continuous tests. Kinetic studies, under different operating conditions, showed that reduction of Cr(VI) could be expressed by a pseudo second-order reaction kinetic. The reaction rate increased with the square of Fe(0) amount, while it was inversely proportional to the initial chromium concentration. The process performance was satisfactory also under uncontrolled pH, and a limited influence of temperature was observed. The reactive material was efficiently reusable for many cycles without any regeneration treatment. The performances in continuous tests were close to 97% for about 80 pore volume of reactive material. PMID:28773785

Use of porous materials to remove oil contaminants from water.

PubMed

Gołub, Adam; Piekutin, Janina

2018-06-15

The purpose of the research was to remove petroleum substances from water using porous materials. Birch bark, cork, glass wool and polyurethane foam were used for the study. The model solution was distilled water enriched with a mixture of petrol and diesel fuel in a volume ratio of 1:3. The model water used had 3 different concentrations of oil substances. The research included petroleum substances expressed as mineral oil index and aliphatic hydrocarbons, n-alkanes (from C7H16 to C38H78). The process of oil substances removal was carried out applying two methods: static and dynamic. Based on the research, it was found that materials the most effective in lowering the index of mineral oil and C7H16-C38H78 n-alkane concentrations were both birch bark and glass wool, both static and dynamic, while cork and polyurethane foam were less effective. In addition, concentration of C7H16-C38H78 n-alkanes was lowered in each measurement series to a greater extent than the mineral oil index. Copyright © 2018 Elsevier B.V. All rights reserved.

Removal of Cr(VI) from Water Using a New Reactive Material: Magnesium Oxide Supported Nanoscale Zero-Valent Iron.

PubMed

Siciliano, Alessio

2016-08-06

The chromium pollution of water is an important environmental and health issue. Cr(VI) removal by means of metallic iron is an attractive method. Specifically, nanoscopic zero valent iron (NZVI) shows great reactivity, however, its applicability needs to be further investigated. In the present paper, NZVI was supported on MgO grains to facilitate the treatments for remediation of chromium-contaminated waters. The performances and mechanisms of the developed composite, in the removal of hexavalent chromium, were investigated by means of batch and continuous tests. Kinetic studies, under different operating conditions, showed that reduction of Cr(VI) could be expressed by a pseudo second-order reaction kinetic. The reaction rate increased with the square of Fe(0) amount, while it was inversely proportional to the initial chromium concentration. The process performance was satisfactory also under uncontrolled pH, and a limited influence of temperature was observed. The reactive material was efficiently reusable for many cycles without any regeneration treatment. The performances in continuous tests were close to 97% for about 80 pore volume of reactive material.

High-rate activated sludge system for carbon management--Evaluation of crucial process mechanisms and design parameters.

PubMed

Jimenez, Jose; Miller, Mark; Bott, Charles; Murthy, Sudhir; De Clippeleir, Haydee; Wett, Bernhard

2015-12-15

The high-rate activated sludge (HRAS) process is a technology suitable for the removal and redirection of organics from wastewater to energy generating processes in an efficient manner. A HRAS pilot plant was operated under controlled conditions resulting in concentrating the influent particulate, colloidal, and soluble COD to a waste solids stream with minimal energy input by maximizing sludge production, bacterial storage, and bioflocculation. The impact of important process parameters such as solids retention time (SRT), hydraulic residence time (HRT) and dissolved oxygen (DO) levels on the performance of a HRAS system was demonstrated in a pilot study. The results showed that maximum removal efficiencies of soluble COD were reached at a DO > 0.3 mg O2/L, SRT > 0.5 days and HRT > 15 min which indicates that minimizing the oxidation of the soluble COD in the high-rate activated sludge process is difficult. The study of DO, SRT and HRT exhibited high degree of impact on the colloidal and particulate COD removal. Thus, more attention should be focused on controlling the removal of these COD fractions. Colloidal COD removal plateaued at a DO > 0.7 mg O2/L, SRT > 1.5 days and HRT > 30 min, similar to particulate COD removal. Concurrent increase in extracellular polymers (EPS) production in the reactor and the association of particulate and colloidal material into sludge flocs (bioflocculation) indicated carbon capture by biomass. The SRT impacted the overall mass and energy balance of the high-rate process indicating that at low SRT conditions, lower COD mineralization or loss of COD content occurred. In addition, the lower SRT conditions resulted in higher sludge yields and higher COD content in the WAS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Methods and systems for utilizing carbide lime or slag

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

Devenney, Martin; Fernandez, Miguel; Chen, Irvin

Provided herein are methods comprising a) treating a slag solid or carbide lime suspension with an ammonium salt in water to produce an aqueous solution comprising calcium salt, ammonium salt, and solids; b) contacting the aqueous solution with carbon dioxide from an industrial process under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the precipitation material and the supernatant aqueous solution comprise residual ammonium salt; and c) removing and optionally recovering ammonia and/or ammonium salt using one or more steps of (i) recovering a gas exhaust stream comprising ammoniamore » during the treating and/or the contacting step; (ii) recovering the residual ammonium salt from the supernatant aqueous solution; and (iii) removing and optionally recovering the residual ammonium salt from the precipitation material.« less

Planetary quarantine

NASA Technical Reports Server (NTRS)

1971-01-01

Methods for presterilization cleaning or decontamination of spacecraft hardware to reduce microbial load, without harming materials or spacecraft components, are investigated. Three methods were considered: (1) chemicals in liquid form, relying on physical removal as well as bacterial or bacteriostatic action; (2) chemicals used in the gaseous phase, relying on bacterial activity; and (3) mechanical cleaning relying on physical removal of organisms. These methods were evaluated in terms of their effectiveness in microbial burden reduction and compatibility with spacecraft hardware. Results show chemical methods were effective against spore microorganisms but were harmful to spacecraft materials. Mechanical methods were also effective with the degree depending upon the type of instrument employed. Mechanical methods caused problems in handling the equipment, due to vacuum pressure damaging the very thin layered materials used for shielding, and the bristles used in the process caused streaks or abrasions on some spacecraft components.

Arsenic Adsorption from Water Using Graphene-Based Materials as Adsorbents: a Critical Review

NASA Astrophysics Data System (ADS)

Yang, Xuetong; Xia, Ling; Song, Shaoxian

2017-07-01

Adsorption is widely applied to remove arsenic from water. This paper reviewed and compared the recent progresses on the arsenic removal by adsorption using two-dimensional and three-dimensional graphene-based materials as adsorbents. Functional graphene sheet achieved the largest As(III) adsorption capacity of 138.79mg/g, while Mg-Al LDH/GO2 showed the largest As(V) adsorption capacity of 183.11mg/g. Parameters including pH, temperature, co-existing ions and loaded metal or metal oxide affected the adsorption process. The adsorption mechanisms of graphene-based materials for As(III) and As(V) could be explained by surface complexation and the electrostatic attraction, respectively. Future works are suggested to focus on regenerating of two-dimensional graphene-based adsorbents and developing the three-dimensional with large specific surface area and better adsorption performance.

Selective Familiarity Deficits after Left Anterior Temporal-Lobe Removal with Hippocampal Sparing Are Material Specific

ERIC Educational Resources Information Center

Martin, Chris B.; Bowles, Ben; Mirsattari, Seyed M.; Kohler, Stefan

2011-01-01

Research has firmly established a link between recognition memory and the functional integrity of the medial temporal lobes (MTL). Dual-process models of MTL organization maintain that there is a division of labour within the MTL, with the hippocampus (HC) supporting recollective processes and perirhinal cortex (PRc) supporting familiarity…

Molecular sieving silica membrane fabrication process

DOEpatents

Raman, N.K.; Brinker, C.J.

1999-08-10

A process is described for producing a molecular sieve silica membrane comprising depositing a hybrid organic-inorganic polymer comprising at least one organic constituent and at least one inorganic constituent on a porous substrate material and removing at least a portion of the at least one organic constituent of the hybrid organic-inorganic polymer, forming a porous film. 11 figs.

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2012 CFR

2012-04-01

....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under... vinous character of the wine (2) None of the stripping solution may migrate into the wine. Reverse osmosis 1 To reduce the ethyl alcohol content of wine and to remove off flavors in wine Permeable...

27 CFR 24.248 - Processes authorized for the treatment of wine, juice, and distilling material.

Code of Federal Regulations, 2013 CFR

2013-04-01

....2910. 1 This process must be done on distilled spirits plant premises. However, reverse osmosis, under... vinous character of the wine (2) None of the stripping solution may migrate into the wine. Reverse osmosis 1 To reduce the ethyl alcohol content of wine and to remove off flavors in wine Permeable...

Purification processes of xenogeneic bone substitutes and their impact on tissue reactions and regeneration.

PubMed

Perić Kačarević, Zeljka; Kavehei, Faraz; Houshmand, Alireza; Franke, Jörg; Smeets, Ralf; Rimashevskiy, Denis; Wenisch, Sabine; Schnettler, Reinhard; Jung, Ole; Barbeck, Mike

2018-04-01

Xenogeneic bone substitute materials are widely used in oral implantology. Prior to their clinical use, purification of the former bone tissue has to be conducted to ensure the removal of immunogenic components and pathogens. Different physicochemical methods are applied for purification of the donor tissue, and temperature treatment is one of these methods. Differences in these methods and especially the application of different temperatures for purification may lead to different material characteristics, which may influence the tissue reactions to these materials and the related (bone) healing process. However, little is known about the different material characteristics and their influences on the healing process. Thus, the aim of this mini-review is to summarize the preparation processes and the related material characteristics, safety aspects, tissue reactions, resorbability and preclinical and clinical data of two widely used xenogeneic bone substitutes that mainly differ in the temperature treatment: sintered (cerabone ® ) and non-sintered (Bio-Oss ® ) bovine-bone materials. Based on the summarized data from the literature, a connection between the material-induced tissue reactions and the consequences for the healing processes are presented with the aim of translation into their clinical application.

Trace metal distribution and control in the pilot-scale bubbling fluidized bed combustor equipped with the pulse-jet fabric filter, limestone injection, and the humidification reactor.

PubMed

Kouvo, Petri

2003-04-01

This work focused on trace metal behavior and removal in a fabric filter or in a humidification reactor during the cofiring of sawdust and refuse-derived fuels (RDFs) in a pilot-scale bubbling fluidized bed (BFB) boiler. Trace metal emissions measurements before and after the fabric filter revealed that removal efficiency in the fabric filter was in the range of 80-100%, and that the European Union (EU) Directive on Incineration of Waste restrictions for trace metal emissions are easily achieved even if addition of RDFs substantially increases the concentration of trace metals in fuel blends. Limestone injection enhanced the removal of As and Se but had no noticeable effect on the removal of other trace metals. Extensive formation of HgCl2 and condensation on fly ash particles during sawdust plus 40% RDF cofiring resulted in a 92% Hg removal efficiency in the fabric filter. Limestone injection had no effect on the Hg removal in the fabric filter but decreased the Hg removal in a humidification reactor from 40 to 28%. Results of the bed material and fly ash analysis suggested capture of Cu, Pb, Mn, Ni, and Zn in the bed material but also suggested that these metals may be released from the bed if the fuel characteristics or process conditions are changed.

Fundamental investigation on influence of external heat on chip formation during thermal assisted machining

NASA Astrophysics Data System (ADS)

Alkali, A. U.; Ginta, T. L.; Abdulrani, A. M.; Elsiti, N. M.

2018-04-01

Various heat sources have been investigated by numerous researchers to reveal machinability benefits of thermally assisted machining (TAM) process. Fewer engineering materials have been tested. In the same vein, those researches continue to demonstrate effective performance of TAM in terms of bulk material removal rate, improved surface finish, prolong tool life and reduction of cutting forces among others. Experimental investigation on the strain-hardenability and flow stress of material removed with respect to increase in temperature in TAM has not been given attention in previous studies. This study investigated the pattern of chip morphology and segmentation giving close attention to influence of external heat source responsible for strain – hardenability of the material removed during TAM and dry machining at room temperature. Full immersion down cut milling was used throughout the machining conditions. Machining was conducted on AISI 316L using uncoated tungsten carbide end mill insert at varying cutting speeds (V) of 50, 79, and 100 m/min, and feed rates (f) of 0.15, 0.25, and 0.4 mm/tooth while the depth of cut was maintained at 0.2mm throughout the machining trials. The analyses of chip formation, segmentations and stain hardenability were carried out by using LMU light microscope, field emission microscopy and micro indentation. The study observed that build up edge is formed when a stagnation zone develops in front of tool tip which give rise to poor thermal gradient for conduction heat to be transferred within the bulk material during dry machining. This promotes varying strain – hardening of the material removed with evident high chips hardness and thickness, whereas TAM circumvents such impairment by softening the shear zone through local preheat.

Environmentally Safe and Effective Processes for Paint Removal

DTIC Science & Technology

1995-04-01

Urea Formaldehyde 3.5 1.5 Type III Melamine Formaldehyde 4.0 1.5 Type IV Phenol Formaldehyde 3.5 1.5...Polyester 3.0 34 - 42 1.04 - 1.46 Type II Urea Formaldehyde 3.5 54 - 62 1.47- 1.54 Type III Melamine Formaldehyde 4.0 64- 72 1.47- 1.52 Type IV Phenol... Melamine Formaldehyde electronics industry and to remove coatings from fibreglass and composite materials. Melamine formaldehyde resin is produced

Removal of Oxygen from Electronic Materials by Vapor-Phase Processes

NASA Technical Reports Server (NTRS)

Palosz, Witold

1997-01-01

Thermochemical analyses of equilibrium partial pressures over oxides with and without the presence of the respective element condensed phase, and hydrogen, chalcogens, hydrogen chalcogenides, and graphite are presented. Theoretical calculations are supplemented with experimental results on the rate of decomposition and/or sublimation/vaporization of the oxides under dynamic vacuum, and on the rate of reaction with hydrogen, graphite, and chalcogens. Procedures of removal of a number of oxides under different conditions are discussed.

Waterjet processes for coating removal

NASA Technical Reports Server (NTRS)

Burgess, Fletcher; Cosby, Steve; Hoppe, David

1995-01-01

USBI and NASA have been testing and investigating the use of high pressure water for coating removal for approximately the past 12 years at the Automated TPS (Thermal Protection System - ablative materials used for thermal protection during ascent and descent of the solid rocket boosters) Removal Facility located in the Productivity Enhancement Complex at Marshall Space Flight Center. Originally the task was to develop and automate the removal process and transfer the technology to a production facility at Kennedy Space Center. Since that time more and more applications and support roles for the waterjet technology have been realized. The facility has become a vital part of development activities ongoing at MSFC. It supports the development of environmentally compliant insulations, sealants, and coatings. It also supports bonding programs, test motors, and pressure vessels. The most recent role of the cell is supporting Thiokol Corporation's solid rocket motor program in the development of waterjet degreasing and paint stripping methods. Currently vapor degreasing methods use 500,000 lbs. of ozone depleting chemicals per year. This paper describes the major cell equipment, test methods practiced, and coatings that have been removed.

A green procedure using ozone for Cleaning-in-Place in the beverage industry.

PubMed

Nishijima, Wataru; Okuda, Tetsuji; Nakai, Satoshi; Okada, Mitsumasa

2014-06-01

Cleaning-in-Place (CIP) in the beverage industry is typically carried out in production lines with alkaline and acidic solutions with detergents. This cleaning not only produces alkaline and acidic wastewater with detergents but also takes significant time. One of the important targets for CIP is adsorbed odorous compounds on gaskets, hence, we have tried to establish a rapid and green CIP process to remove traces of such compounds, especially d-limonene, an odorous component of orange juice, using two approaches; an ozone cleaning method and a change of gasket material from ethylene propylene diene monomer (EPDM) rubber to silicone rubber. By changing the gasket material from EPDM rubber to silicone rubber, the removability of d-limonene by typical alkaline and acidic cleanings with detergents was improved. However, complete removal of 4 mg g(-1) of d-limonene on both EPDM and silicone gaskets could not be achieved even using a series of conventional cleaning procedures that included alkaline and acidic cleaning for 220 min. Ozone treatment dramatically improved the removability of d-limonene, removing 87% from the EPDM gasket at 60 min and 100% from the silicone gasket at 30 min. The combination of the silicone gasket and ozone treatment resulted in the most effective cleaning. The main removal mechanism for ozone treatment was confirmed to be oxidation by molecular ozone. Effectiveness of changing the gasket material from EPDM rubber to silicone rubber in reducing residual amounts of odorous compounds adsorbed on the gaskets was also confirmed for furfural and 4-vinylguaiacol. Copyright © 2014 Elsevier Ltd. All rights reserved.

Novel sequential process for enhanced dye synergistic degradation based on nano zero-valent iron and potassium permanganate.

PubMed

Wang, Xiangyu; Liu, Peng; Fu, Minglai; Ma, Jun; Ning, Ping

2016-07-01

A novel synergistic technology based on nano zero-valent iron (NZVI) and potassium permanganate (KMnO4) was developed for treatment of dye wastewater. The synergistic technology was significantly superior, where above 99% of methylene blue (MB) was removed, comparatively, removal efficiencies of MB with the sole technology of NZVI and KMnO4 at pH 6.39 being 52.9% and 63.1%, respectively. The advantages of this technology include (1) the in situ formed materials (manganese (hydr)oxides, iron hydroxides and MnFe oxide), resulting in the stable and high removal efficiency of MB and (2) high removal capacity in a wide range of pH value. Compared with simultaneous addition system of NZVI and KMnO4, MB removal was remarkably improved by sequential addition system, especially when KMnO4 addition time was optimized at 20 min. Analyses of crystal structure (XRD), morphological difference (FE-SEM), element valence and chemical groups (XPS) of NZVI before and after reaction had confirmed the formation of in situ materials, which obviously enhanced removal of MB by oxidation and adsorption. More importantly, the roles of in situ formed materials and degradation mechanism were innovatively investigated, and the results suggested that NCH3 bond of MB molecule was attacked by oxidants (KMnO4 and in situ manganese (hydr)oxides) at position C1 and C9, resulting in cleavage of chromophore. This study provides new insights about an applicable technology for treatment of dye wastewater. Copyright © 2016. Published by Elsevier Ltd.

Integrated acid mine drainage management using fly ash.

PubMed

Vadapalli, Viswanath R K; Gitari, Mugera W; Petrik, Leslie F; Etchebers, Olivier; Ellendt, Annabelle

2012-01-01

Fly Ash (FA) from a power station in South Africa was investigated to neutralise and remove contaminants from Acid Mine Drainage (AMD). After this primary treatment the insoluble FA residue namely solid residue (SR) was investigated as a suitable mine backfill material by means of strength testing. Moreover, SR was used to synthesise zeolite-P using a two-step synthesis procedure. Furthermore, the zeolite-P was investigated to polish process water from the primary FA-AMD reaction. The main objective of this series of investigations is to achieve zero waste and to propose an integrated AMD management using FA. Fly Ash was mixed with AMD at various predetermined FA-AMD ratios until the mixtures achieved circumneutral pH or higher. The supernatants were then analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Ion Chromatography (IC) for cations and anions respectively. The physical strength testing of SR was carried out by mixing it with 3% Ordinary Portland Cement (OPC) and curing for 410 days. Synthesis of zeolite-P using SR was carried out by two step synthesis procedure: ageing for 24 hours followed by a mild hydrothermal synthesis at 100°C for 4 days. The polishing of process water from primary AMD treatment using FA was ascertained by mixing the process water with zeolite at a liquid to solid ratio of 100:1 for 1 hour. The results indicated that FA can be successfully used to ameliorate AMD. High removal of major AMD contaminants Fe, Al, Mg, Mn and sulphate was achieved with the ash treatment and trace elements such as Zn, Ni, Cu and Pb were also removed by the FA. Strength testing over 410 days indicated that the material gained strength over the testing period. The maximum unconfined compressive strength and elastic modulus was observed to be approximately 0.3 MPa and 150 Mpa respectively. The X-ray diffraction (XRD) analysis of the synthesized product indicated that SR was successfully converted into zeolite-P with some mullite phase remaining as a result of incomplete conversion of the feedstock SR. The zeolite-P was used as an ion exchange material to remove selective elements from the process water. Elements such as Ca, Sr, Ba and V were successfully removed from the process water with the zeolite-P. Only marginal removal of Mo was observed during the experiments. It was also observed that Na was exchanged into the solution. This study successfully demonstrated zero waste concepts and an integrated AMD management scheme using FA was developed in this study. The implementation of this technology will address FA storage problem as well as costs associated with AMD treatment.

Modified Rice Straw as Adsorbent Material to Remove Aflatoxin B1 from Aqueous Media and as a Fiber Source in Fino Bread

PubMed Central

Mohamed, Sherif R.; El-Desouky, Tarek A.; Hussein, Ahmed M. S.; Mohamed, Sherif S.; Naguib, Khayria M.

2016-01-01

The aims of the current work are in large part the benefit of rice straw to be used as adsorbent material and natural source of fiber in Fino bread. The rice straw was subjected to high temperature for modification process and the chemical composition was carried out and the native rice straw contained about 41.15% cellulose, 20.46% hemicellulose, and 3.91% lignin while modified rice straw has 42.10, 8.65, and 5.81%, respectively. The alkali number was tested and showed an increase in the alkali consumption due to the modification process. The different concentrations of modified rice straw, aflatoxin B1, and pH were tested for removal of aflatoxin B1 from aqueous media and the maximum best removal was at 5% modified rice straw, 5 ng/mL aflatoxin B1, and pH 7. The modified rice straw was added to Fino bread at a level of 5, 10, and 15% and the chemical, rheological, baking quality, staling, and sensory properties were studied. Modified rice straw induced an increase of the shelf life and the produced Fino bread has a better consistency. PMID:26989411

Treatment of real wastewater produced from Mobil car wash station using electrocoagulation technique.

PubMed

El-Ashtoukhy, E-S Z; Amin, N K; Fouad, Y O

2015-10-01

This paper deals with the electrocoagulation of real wastewater produced from a car wash station using a new cell design featuring a horizontal spiral anode placed above a horizontal disc cathode. The study dealt with the chemical oxygen demand (COD) reduction and turbidity removal using electrodes in a batch mode. Various operating parameters such as current density, initial pH, NaCl concentration, temperature, and electrode material were examined to optimize the performance of the process. Also, characterization of sludge formed during electrocoagulation was carried out. The results indicated that the COD reduction and turbidity removal increase with increasing the current density and NaCl concentration; pH from 7 to 8 was found to be optimum for treating the wastewater. Temperature was found to have an insignificant effect on the process. Aluminum was superior to iron as a sacrificial electrode material in treating car wash wastewater. Energy consumption based on COD reduction ranged from 2.32 to 15.1 kWh/kg COD removed depending on the operating conditions. Finally, the sludge produced during electrocoagulation using aluminum electrodes was characterized by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analysis.

Method for processing aqueous wastes

DOEpatents

Pickett, J.B.; Martin, H.L.; Langton, C.A.; Harley, W.W.

1993-12-28

A method is presented for treating waste water such as that from an industrial processing facility comprising the separation of the waste water into a dilute waste stream and a concentrated waste stream. The concentrated waste stream is treated chemically to enhance precipitation and then allowed to separate into a sludge and a supernate. The supernate is skimmed or filtered from the sludge and blended with the dilute waste stream to form a second dilute waste stream. The sludge remaining is mixed with cementitious material, rinsed to dissolve soluble components, then pressed to remove excess water and dissolved solids before being allowed to cure. The dilute waste stream is also chemically treated to decompose carbonate complexes and metal ions and then mixed with cationic polymer to cause the precipitated solids to flocculate. Filtration of the flocculant removes sufficient solids to allow the waste water to be discharged to the surface of a stream. The filtered material is added to the sludge of the concentrated waste stream. The method is also applicable to the treatment and removal of soluble uranium from aqueous streams, such that the treated stream may be used as a potable water supply. 4 figures.

An experimental analysis of strontium titanate ceramic substrates polished by magnetorheological finishing with dynamic magnetic fields formed by rotating magnetic poles

NASA Astrophysics Data System (ADS)

Pan, Jisheng; Yu, Peng; Yan, Qiusheng; Li, Weihua

2017-05-01

Strontium titanate (SrTiO3, STO) ceramic substrate is an incipient ferroelectric material with a perovskite structure and which has a wide range of applications in the fields of microwave, millimetre wave, and optic fibre. This paper reports on a system of experiments carried out on STO substrates using a new magnetorheological (MR) finishing process where dynamic magnetic fields are formed by magnetic poles rotate. The results show that a circular ring shaped polishing belt with a stability evaluation zone appears on the surface after being polished by MR finishing with a single-point dynamic magnetic field. The dynamic magnetic fields are stronger when the revolutions of magnetic pole increase and eccentricity of pole enlarge, with the surface finish is smoother and more material is removed. The optimum machining times, machining gap, oscillation distance, eccentricity of pole, revolutions of the workpiece and magnetic pole are 60 min, 0.8 mm, 0 mm, 7 mm, and 350 r min-1 and 90 r min-1, respectively, and the best MR fluid consists of 6 wt% of diamond abrasives in W1 particle size and 18 wt% of carbonyl iron powder in W3.5 particle size. A surface roughness of Ra and a material removal rate of 8 nm and 0.154 μm min-1 can be obtained in these optimum process conditions. Finally, the polishing mechanism for dynamic magnetic fields and the mechanism for removing material from STO ceramic substrates are discussed in detail.

High density circuit technology, part 1

NASA Technical Reports Server (NTRS)

Wade, T. E.

1982-01-01

The metal (or dielectric) lift-off processes used in the semiconductor industry to fabricate high density very large scale integration (VLSI) systems were reviewed. The lift-off process consists of depositing the light-sensitive material onto the wafer and patterning first in such a manner as to form a stencil for the interconnection material. Then the interconnection layer is deposited and unwanted areas are lifted off by removing the underlying stencil. Several of these lift-off techniques were examined experimentally. The use of an auxiliary layer of polyimide to form a lift-off stencil offers considerable promise.

Assessment of Filter Materials for Removal of Contaminants From Agricultural Drainage Waters

NASA Astrophysics Data System (ADS)

Allred, B. J.

2007-12-01

Fertilizer nutrients and pesticides applied on farm fields, especially in the Midwest U.S., are commonly intercepted by buried agricultural drainage pipes and then discharged into local streams and lakes, oftentimes resulting in an adverse environmental impact on these surface water bodies. Low cost filter materials have the potential to remove nutrient and pesticide contaminants from agricultural drainage waters before these waters are released from the farm site. Batch tests were conducted to find filter materials potentially capable of removing nutrient (nitrate and phosphate) and pesticide (atrazine) contaminants from subsurface drainage waters. For each batch test, stock solution (40 g) and filter material (5 g) were combined in 50 mL Teflon centrifuge tubes and mixed with a rotator for 24 hours. The stock solution contained 50 mg/L nitrate-N, 0.25 mg/L phosphate-P, 0.4 mg/L atrazine, 570 mg/L calcium sulfate, and 140 mg/L potassium chloride. Calcium sulfate and potassium chloride were added so that the stock solution would contain anions and cations normally found in agricultural drainage waters. There were six replicate batch tests for each filter material. At the completion of each test, solution was removed from the centrifuge tube and analyzed for nitrate-N, phosphate-P, and atrazine. A total of 38 filter materials were tested, which were divided into five classes; high carbon content substances, high iron content substances, high aluminum content substances, surfactant modified clay/zeolite, and coal combustion products. Batch test results generally indicate, that with regard to the five classes of filter materials; high carbon content substances adsorbed atrazine very effectively; high iron content substances worked especially well removing almost all of the phosphate present; high aluminum content substances lowered phosphate levels; surfactant modified clay/zeolite substantially reduced both nitrate and atrazine; and coal combustion products significantly decreased phosphate amounts. For the 38 specific filter materials evaluated, based on a 60 percent contaminant reduction level, 12 materials removed nitrate, 26 materials removed phosphate, and 21 materials removed atrazine. Furthermore, 2 materials removed zero contaminants, 16 materials removed one contaminant, 17 materials removed two contaminants, and 3 of the materials removed all three contaminants. The most effective filter materials proved to be a steam activated carbon, a zero valent iron and sulfer modified iron mixture, and a surfactant modified clay. The findings of this study indicate that there are a variety of filter materials, either separately or in combination, which have the potential to treat agricultural drainage waters.

Filtering coal-derived oil through a filter media precoated with particles partially solubilized by said oil

DOEpatents

Rodgers, Billy R.; Edwards, Michael S.

1977-01-01

Solids such as char, ash, and refractory organic compounds are removed from coal-derived liquids from coal liquefaction processes by the pressure precoat filtration method using particles of 85-350 mesh material selected from the group of bituminous coal, anthracite coal, lignite, and devolatilized coals as precoat materials and as body feed to the unfiltered coal-derived liquid.

Investigation of wear phenomena by microscopy

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1982-01-01

The various wear mechanisms involved in the loss of material from metallic and nonmetallic surfaces are discussed. The results presented indicate how various microscopy techniques used in conjunction with other analytical tools can assist in the elucidation of a wear mechanism. Without question, microscopy is the single most important tool for the study of the wear of surfaces, to assess and address inherent mechanisms of the material removal process.

Mechanisms of nitrogen retention in forest ecosystems - A field experiment

NASA Technical Reports Server (NTRS)

Vitousek, P. M.; Matson, P. A.

1984-01-01

Intensive forest management led to elevated losses of nitrogen from a recently harvested loblolly pine plantation in North Carolina. Measurements of nitrogen-15 retention in the field demonstrated that microbial uptake of nitrogen during the decomposition of residual organic material was the most important process retaining nitrogen. Management practices that remove this material cause increased losses of nitrogen to aquatic ecosystems and the atmosphere.

Ancient fluvial processes in the equatorial highlands of Mars

NASA Technical Reports Server (NTRS)

Craddock, Robert A.; Maxwell, Ted A.

1991-01-01

Martian highland craters typically lack ejecta deposits, have no noticeable rim, and are flat floored. In addition, crater size frequency distribution curves show that highland craters have depleted populations less than 20 km in diameter. A variety of processes have been suggested to explain these observations including deposition of aeolian or volcanic materials up to the crater rim crests, thermal creep, terrain softening, and mass wasting. However, none of these processes adequately explains both the crater morphology and population distribution. In order to explain both the Martian highland crater morphology and population distribution, a fluvial process is proposed which is capable of removing the loose crater rim material. The resulting effect is to decrease the crater diameter, thereby causing the population curves to bendover. The eroded material is redistributed, burying or partially burying smaller diameter craters before complete erosion. This material may also be deposited into local topographic lows, creating the depositional basins observed. A fluvial process explains both sets of observations: crater morphology and crater population distribution curves.

Microfabrication Method using a Combination of Local Ion Implantation and Magnetorheological Finishing

NASA Astrophysics Data System (ADS)

Han, Jin; Kim, Jong-Wook; Lee, Hiwon; Min, Byung-Kwon; Lee, Sang Jo

2009-02-01

A new microfabrication method that combines localized ion implantation and magnetorheological finishing is proposed. The proposed technique involves two steps. First, selected regions of a silicon wafer are irradiated with gallium ions by using a focused ion beam system. The mechanical properties of the irradiated regions are altered as a result of the ion implantation. Second, the wafer is processed by using a magnetorheological finishing method. During the finishing process, the regions not implanted with ion are preferentially removed. The material removal rate difference is utilized for microfabrication. The mechanisms of the proposed method are discussed, and applications are presented.

Etching process for improving the strength of a laser-machined silicon-based ceramic article

DOEpatents

Copley, Stephen M.; Tao, Hongyi; Todd-Copley, Judith A.

1991-01-01

A process for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength.

Etching process for improving the strength of a laser-machined silicon-based ceramic article

DOEpatents

Copley, S.M.; Tao, H.; Todd-Copley, J.A.

1991-06-11

A process is disclosed for improving the strength of laser-machined articles formed of a silicon-based ceramic material such as silicon nitride, in which the laser-machined surface is immersed in an etching solution of hydrofluoric acid and nitric acid for a duration sufficient to remove substantially all of a silicon film residue on the surface but insufficient to allow the solution to unduly attack the grain boundaries of the underlying silicon nitride substrate. This effectively removes the silicon film as a source of cracks that otherwise could propagate downwardly into the silicon nitride substrate and significantly reduce its strength. 1 figure.

Nitrogen removal in moving bed sequencing batch reactor using polyurethane foam cubes of various sizes as carrier materials.

PubMed

Lim, Jun-Wei; Seng, Chye-Eng; Lim, Poh-Eng; Ng, Si-Ling; Sujari, Amat-Ngilmi Ahmad

2011-11-01

The performance of moving bed sequencing batch reactors (MBSBRs) added with 8 % (v/v) of polyurethane (PU) foam cubes as carrier media in nitrogen removal was investigated in treating low COD/N wastewater. The results indicate that MBSBR with 8-mL cubes achieved the highest total nitrogen (TN) removal efficiency of 37% during the aeration period, followed by 31%, 24% and 19 % for MBSBRs with 27-, 64- and 125-mL cubes, respectively. The increased TN removal in MBSBRs was mainly due to simultaneous nitrification and denitrification (SND) process which was verified by batch studies. The relatively lower TN removal in MBSBR with larger PU foam cubes was attributed to the observation that larger PU foam cubes were not fully attached by biomass. Higher concentrations of 8-mL PU foam cubes in batch reactors yielded higher TN removal. Copyright © 2011 Elsevier Ltd. All rights reserved.

Heavy metal removal using nanoscale zero-valent iron (nZVI): Theory and application.

PubMed

Li, Shaolin; Wang, Wei; Liang, Feipeng; Zhang, Wei-Xian

2017-01-15

Treatment of wastewater containing heavy metals requires considerations on simultaneous removal of different ions, system reliability and quick separation of reaction products. In this work, we demonstrate that nanoscale zero-valent iron (nZVI) is an ideal reagent for removing heavy metals from wastewater. Batch experiments show that nZVI is able to perform simultaneous removal of different heavy metals and arsenic; reactive nZVI in uniform dispersion brings rapid changes in solution E h , enabling a facile way for reaction regulation. Microscope characterizations and settling experiments suggest that nZVI serves as solid seeds that facilitate products separation. A treatment process consisting of E h -controlled nZVI reaction, gravitational separation and nZVI recirculation is then demonstrated. Long-term (>12 months) operation shows that the process achieves >99.5% removal of As, Cu and a number of other toxic elements. The E h -controlled reaction system sustains a highly-reducing condition in reactor and reduces nZVI dosage. The process produces effluent of stable quality that meets local discharge guidelines. The gravitational separator shows high efficacy of nZVI recovery and the recirculation improves nZVI material efficiency, resulting in extraordinarily high removal capacities ((245mg As+226 mg-Cu)/g-nZVI). The work provides proof that nanomaterials can offer truly green and cost-effective solutions for wastewater treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Effectiveness of Rice Agricultural Waste, Microbes and Wetland Plants in the Removal of Reactive Black-5 Azo Dye in Microcosm Constructed Wetlands.

PubMed

Saba, Beenish; Jabeen, Madeeha; Khalid, Azeem; Aziz, Irfan; Christy, Ann D

2015-01-01

Azo dyes are commonly generated as effluent pollutants by dye using industries, causing contamination of surface and ground water. Various strategies are employed to treat such wastewater; however, a multi-faceted treatment strategy could be more effective for complete removal of azo dyes from industrial effluent than any single treatment. In the present study, rice husk material was used as a substratum in two constructed wetlands (CWs) and augmented with microorganisms in the presence of wetland plants to effectively treat dye-polluted water. To evaluate the efficiency of each process the study was divided into three levels, i.e., adsorption of dye onto the substratum, phytoremediation within the CW and then bioremediation along with the previous two processes in the augmented CW. The adsorption process was helpful in removing 50% dye in presence of rice husk while 80% in presence of rice husk biocahr. Augmentation of microorganisms in CW systems has improved dye removal efficiency to 90%. Similarly presence of microorganisms enhanced removal of total nitrogen (68% 0 and Total phosphorus (75%). A significant improvement in plant growth was also observed by measuring plant height, number of leaves and leave area. These findings suggest the use of agricultural waste as part of a CW substratum can provide enhanced removal of textile dyes.

Comparison of the biological NH3 removal characteristics among four inorganic packing materials.

PubMed

Hirai, M; Kamamoto, M; Yani, M; Shoda, M

2001-01-01

Four inorganic packing materials were evaluated in terms of their availability as a packing material of a packed tower deodorization apparatus (biofilter) from the viewpoints of biological NH3 removal characteristics and some physical properties. Porous ceramics (A), calcinated cristobalite (B), calcinated and formed obsidian (C), granulated and calculated soil (D) were used. The superiority of these packing materials determined based on the values of non-biological removal per unit weight or unit volume of packing material, complete removal capacity of NH3 per unit weight of packing material per day or unit volume of packing material per day and pressure drop of the packed bed was in the order of A approximately = C > B > or = D. Packing materials A and C with high porosity, maximum water content, and suitable mean pore diameter showed excellent removal capacity.

Spectroscopic characterization of DOM and the nitrogen removal mechanism during wastewater reclamation plant.

PubMed

Wang, Lei; Li, Ying-Jun; Xiong, Ying; Tan, Wen-Bing; Zhang, Lie-Yu; Li, Xiang; Wang, Xiao-Shu; Xu, Jian-Feng; Li, Tong-Tong; Wang, Jin-Sheng; Cai, Ming-Xuan; Xi, Bei-Dou; Wang, Di-Hua

2017-01-01

The performance of the Sha-he wastewater reclamation plant was evaluated in this study. To remove residual nitrogen after Anaerobic-Anoxic-Oxic (A2O) treatment, three multistage Anoxic-Oxic (A/O) were added to investigate the nitrogen removal efficiency and its mechanism. In addition, the constituents and evolution of dissolved organic matter (DOM) during wastewater reclamation was also investigated using a method combining fluorescence spectroscopy with fluorescence regional integration (FRI). The results suggested that multistage A/O treatment can effectively improve the nitrogen removal ability under low concentrations of carbon sources. The total nitrogen (TN) exhibits significantly positive correlation with fulvic acid-like materials and humic acid-like materials. The correlation coefficient for TN and fulvic acid-like substances (R2 = 0.810, P < 0.01) removal was greater than that of humic acid-like substances (R2 = 0.636, P < 0.05). The results indicate that nitrogen removal may be achieved with the fulvic-like and humic-like substances, and the removal effects were higher by fulvic acid-like substances than humic-like substances, mostly due to that the latter were relatively more difficult to be utilized as carbon source during the nitrogen removal process. The effluent water quality of biological treatment reached the first grade A standard of "Cities sewage treatment plant pollutant discharge standard" (GB18918-2002). In addition, the effluent from the membrane bioreactor reached the "Standards of reclaimed water quality" (SL368-2006).

Spectroscopic characterization of DOM and the nitrogen removal mechanism during wastewater reclamation plant

PubMed Central

Wang, Lei; Li, Ying-Jun; Xiong, Ying; Tan, Wen-Bing; Zhang, Lie-Yu; Li, Xiang; Wang, Xiao-Shu; Xu, Jian-feng; Li, Tong-Tong; Wang, Jin-Sheng; Cai, Ming-Xuan; Xi, Bei-Dou; Wang, Di-Hua

2017-01-01

The performance of the Sha-he wastewater reclamation plant was evaluated in this study. To remove residual nitrogen after Anaerobic-Anoxic-Oxic (A2O) treatment, three multistage Anoxic-Oxic (A/O) were added to investigate the nitrogen removal efficiency and its mechanism. In addition, the constituents and evolution of dissolved organic matter (DOM) during wastewater reclamation was also investigated using a method combining fluorescence spectroscopy with fluorescence regional integration (FRI). The results suggested that multistage A/O treatment can effectively improve the nitrogen removal ability under low concentrations of carbon sources. The total nitrogen (TN) exhibits significantly positive correlation with fulvic acid-like materials and humic acid-like materials. The correlation coefficient for TN and fulvic acid-like substances (R2 = 0.810, P < 0.01) removal was greater than that of humic acid-like substances (R2 = 0.636, P < 0.05). The results indicate that nitrogen removal may be achieved with the fulvic-like and humic-like substances, and the removal effects were higher by fulvic acid-like substances than humic-like substances, mostly due to that the latter were relatively more difficult to be utilized as carbon source during the nitrogen removal process. The effluent water quality of biological treatment reached the first grade A standard of “Cities sewage treatment plant pollutant discharge standard” (GB18918-2002). In addition, the effluent from the membrane bioreactor reached the “Standards of reclaimed water quality” (SL368-2006). PMID:29149172

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James R

2014-11-04

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass

DOEpatents

Elliott, Douglas C; Oyler, James

2013-12-17

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogenous catalyst for gasification.

Raw liquid waste treatment process

NASA Technical Reports Server (NTRS)

Humphrey, Marshall F. (Inventor)

1980-01-01

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, which is suspended in the sewage water is first separated from the water, in which at least organic matter is dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material absorbs organic matter and heavy metal ions, it is believed, are dissolved in the water and is thereafter supplied in a counter current flow direction and combined with the incoming raw sewage to facilitate the separation of the non-dissolved settleable materials from the sewage water. The used carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Raw Liquid Waste Treatment System and Process

NASA Technical Reports Server (NTRS)

Humphrey, M. F. (Inventor)

1974-01-01

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, suspended in the sewage water is first separated from the water, in which at least organic matter remains dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material adsorbs the organic matter dissolved in the water and is thereafter supplied in a counter flow direction and combined with the incoming raw sewage to at least facilitate the separation of the non-dissolved settleable materials from the sewage water. Carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Purification of trona ores by conditioning with an oil-in-water emulsion

DOEpatents

Miller, J. D.; Wang, Xuming; Li, Minhua

2009-04-14

The present invention is a trona concentrate and a process for floating gangue material from trona ore that comprises forming an emulsion, conditioning the trona ore at a high solids content in a saturated trona suspension, and then floating and removing the gangue material. The process for separating trona from gangue materials in trona ore can include emulsifying an oil in an aqueous solution to form an oil-in-water emulsion. A saturated trona suspension having a high solids content can also be formed having trona of a desired particle size. The undissolved trona in the saturated suspension can be conditioned by mixing the saturated suspension and the oil-in-water emulsion to form a conditioning solid suspension of trona and gangue material. A gas can be injected through the conditioning solid suspension to float the gangue material. Thus, the floated gangue material can be readily separated from the trona to form a purified trona concentrate without requirements of additional heat or other expensive processing steps.

A Review on Adsorption of Fluoride from Aqueous Solution

PubMed Central

Habuda-Stanić, Mirna; Ergović Ravančić, Maja; Flanagan, Andrew

2014-01-01

Fluoride is one of the anionic contaminants which is found in excess in surface or groundwater because of geochemical reactions or anthropogenic activities such as the disposal of industrial wastewaters. Among various methods used for defluoridation of water such as coagulation, precipitation, membrane processes, electrolytic treatment, ion-exchange, the adsorption process is widely used. It offers satisfactory results and seems to be a more attractive method for the removal of fluoride in terms of cost, simplicity of design and operation. Various conventional and non-conventional adsorbents have been assessed for the removal of fluoride from water. In this review, a list of various adsorbents (oxides and hydroxides, biosorbents, geomaterials, carbonaceous materials and industrial products and by-products) and its modifications from literature are surveyed and their adsorption capacities under various conditions are compared. The effect of other impurities on fluoride removal has also been discussed. This survey showed that various adsorbents, especially binary and trimetal oxides and hydroxides, have good potential for the fluoride removal from aquatic environments. PMID:28788194

Excimer laser decoating of chromium titanium aluminium nitride to facilitate re-use of cutting tools

NASA Astrophysics Data System (ADS)

Sundar, M.; Whitehead, D.; Mativenga, P. T.; Li, L.; Cooke, K. E.

2009-11-01

This work reports on the technical feasibility and establishment of a process window for removing chromium titanium aluminium nitride (CrTiAlN) coating from steel substrates by laser irradiation. CrTiAlN coating has high hardness and oxidation resistance, with applications for use with cutting tools. The motivation for removing such coatings is to facilitate re-use of tooling by enabling regrinding or reshaping of a worn tool and hence promote sustainable material usage. In this work, laser decoating was performed using an excimer laser. The effect of laser fluence, number of pulses, frequency, scanning speed and laser beam overlap on the decoating performance was investigated in detail. The minimum threshold laser fluence for removing the CrTiAlN coating was lower than that of the steel substrate and this factor is beneficial in controlling the decoating process. Successful laser removal of CrTiAlN coating without noticeable damage to the steel substrate was demonstrated.

Fixed bed column study for water defluoridation using neem oil-phenolic resin treated plant bio-sorbent.

PubMed

Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Adhikari, Basudam; Das, Papita

2018-04-15

Fluoride has both detrimental and beneficial effects on living beings depending on the concentration and consumption periods. The study presented in this article investigated the feasibility of using neem oil phenolic resin treated lignocellulosic bio-sorbents for fluoride removal from water through fixed bed column study. Results indicated that treated bio-sorbents could remove fluoride both from synthetic and groundwater with variable bed depth, flow rate, fluoride concentration and column diameter. Data obtained from this study indicated that columns with the thickest bed, lowest flow rate, and fluoride concentration showed best column performance. Bio-sorbents used in this study are regenerable and reusable for more than five cycles. The initial materials cost needed to remove one gram of fluoride also found to be lower than the available alternatives. This makes the process more promising candidate to be used for fluoride removal. In addition, the process is also technically advantageous over the available alternatives. Copyright © 2018 Elsevier Ltd. All rights reserved.

Formula for the Removal and Remediation of Polychlorinated Biphenyls in Painted Structures

NASA Technical Reports Server (NTRS)

Quinn, Jacqueline; Loftin, Kathleen; Geiger, Cherie

2010-01-01

An activated metal treatment system (AMTS) removes and destroys polychlorinated biphenyls (PCBs) found in painted structures or within the binding or caulking material on structures. It may be applied using a "paint-on and wipe-off" process that leaves the structure PCB-free and virtually unaltered in physical form. AMTS is used in conjunction with a solvent solution capable of donating hydrogen atoms. AMTS as a treatment technology has two functions: first, to extract PCBs from the material, and second, to degrade the extracted PCBs. The process for removing PCBs from structures is accomplished as an independent step to the degradation process. The goal is to extract the PCBs out of the paint, without destroying the paint, and to partition the PCBs into an environmentally friendly solvent. The research to date indicates this can be accomplished within the first 24 hours of AMTS contact with the paint. PCBs are extremely hydrophobic and prefer to be in the AMTS over the hardened paint or binder material. The solvent selected must be used to open, but not to destroy, the paint s polymeric lattice structure, allowing pathways for PCB movement out of the paint and into the solvent. A number of solvent systems were tested and are available for use within the AMTS. The second process of the AMTS is the degradation or dehalogenation of the PCBs. The solvent selection for this process is limited to solvents that are capable of donating a hydrogen atom to the PCB structure. Additional AMTS formulation properties that must be addressed for each site-specific application include viscosity and stability. The AMTS must be thick enough to remain where it is applied. Several thickening agents have been tested. Adding a stabilizing agent ensures that the AMTS will not evaporate and leave unprotected, activated metal exposed. During AMTS formulation testing, a number of reagents were evaluated to ensure the rate of dehalogenation was not inhibited by its addition to the system.

Combined SO sub x /NO sub x removal and concentration from flue gas through an electrochemical membrane

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

Winnick, J.

1989-11-01

Electrochemical membrane removal of SO{sub 2} from flue gas and concentration into a salable by-product stream has been achieved. Full-cell tests have verified both the concept and choice of materials compatible with the process gas. Electrodes have been developed, manufactured from a conducting ceramic, La{sub 0.8}Sr{sub 0.2}CoO{sub 3}. Electrochemical cell reactions conform precisely with those discerned in free electrolyte. These reactions are stoichiometric to over 95% SO{sub 2} removal. Oleum by-product generation is likewise totally stoichiometric (100% current efficiency). NO{sub x} removal has been found to occur at the oxidizing electrode. Cell polarization, that is, the achievable current densities atmore » reasonable voltage, is unacceptable with the membranes tested thus far. Future work will focus on identifying a ceramic matrix material and a membrane fabrication technique which yields a membrane with the proper capillarity match with the porous electrodes. This will give the cell the proper polarization performance to permit larger scale endurance tests. 56 figs.« less

Laser balancing system for high material removal rates

NASA Technical Reports Server (NTRS)

Jones, M. G.; Georgalas, G.; Ortiz, A. L.

1984-01-01

A laser technique to remove material in excess of 10 mg/sec from a spinning rotor is described. This material removal rate is 20 times greater than previously reported for a surface speed of 30 m/sec. Material removal enhancement was achieved by steering a focused laser beam with moving optics to increase the time of laser energy interaction with a particular location on the circumferential surface of a spinning rotor. A neodymium:yttrium aluminum garnet (Nd:YAG) pulse laser was used in this work to evaluate material removal for carbon steel, 347 stainless steel, Inconal 718, and titanium 6-4. This technique is applicable to dynamic laser balancing.

Machining of Fibre Reinforced Plastic Composite Materials.

PubMed

Caggiano, Alessandra

2018-03-18

Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented.

Machining of Fibre Reinforced Plastic Composite Materials

PubMed Central

2018-01-01

Fibre reinforced plastic composite materials are difficult to machine because of the anisotropy and inhomogeneity characterizing their microstructure and the abrasiveness of their reinforcement components. During machining, very rapid cutting tool wear development is experienced, and surface integrity damage is often produced in the machined parts. An accurate selection of the proper tool and machining conditions is therefore required, taking into account that the phenomena responsible for material removal in cutting of fibre reinforced plastic composite materials are fundamentally different from those of conventional metals and their alloys. To date, composite materials are increasingly used in several manufacturing sectors, such as the aerospace and automotive industry, and several research efforts have been spent to improve their machining processes. In the present review, the key issues that are concerning the machining of fibre reinforced plastic composite materials are discussed with reference to the main recent research works in the field, while considering both conventional and unconventional machining processes and reporting the more recent research achievements. For the different machining processes, the main results characterizing the recent research works and the trends for process developments are presented. PMID:29562635

Peroxidase extraction from jicama skin peels for phenol removal

NASA Astrophysics Data System (ADS)

Chiong, T.; Lau, S. Y.; Khor, E. H.; Danquah, M. K.

2016-06-01

Phenol and its derivatives exist in various types of industrial effluents, and are known to be harmful to aquatic lives even at low concentrations. Conventional treatment technologies for phenol removal are challenged with long retention time, high energy consumption and process cost. Enzymatic treatment has emerged as an alternative technology for phenol removal from wastewater. These enzymes interact with aromatic compounds including phenols in the presence of hydrogen peroxide, forming free radicals which polymerize spontaneously to produce insoluble phenolic polymers. This work aims to extract peroxidase from agricultural wastes materials and establish its application for phenol removal. Peroxidase was extracted from jicama skin peels under varying extraction conditions of pH, sample-to-buffer ratio (w/v %) and temperature. Experimental results showed that extraction process conducted at pH 10, 40% w/v and 25oC demonstrated a peroxidase activity of 0.79 U/mL. Elevated temperatures slightly enhanced the peroxidase activities. Jicama peroxidase extracted at optimum extraction conditions demonstrated a phenol removal efficiency of 87.5% at pH 7. Phenol removal efficiency was ∼ 97% in the range of 30 - 40oC, and H2O2 dosage has to be kept below 100 mM for maximum removal under phenol concentration tested.

Removal of Chromophoric Dissolved Organic Matter and Heavy Metals in a River-Sea System: Role of Aquatic Microgel Formation

NASA Astrophysics Data System (ADS)

Shiu, R. F.; Lee, C. L.

2016-12-01

Dissolved organic carbon (DOC) polymers are complex and poorly understood mixture of organic macromolecules in environment system. Portions of these polymers spontaneously form microgels that play key roles in many biogeochemical reactions, including mediating aggregation processes, element cycling, and pollutant mobility. However, the detailed interaction of microgels-heterogeneous materials in aquatic systems is still lacking. Insight into the interaction between surrounding materials and microgels from different types of aquatic DOC polymers are extremely important, as it is crucial in determining the fate and transport of these materials. Here, we use riverine and marine DOC polymers to examine their aggregation behavior, and to evaluate the roles of microgel formation in scavenging of chromophoric dissolved organic matter (CDOM) and heavy metals in a river-sea system. Our results indicate that riverine and marine microgels did not exhibit too much difference in size ( 3-5 μm) and self-assembly curve; however, the assembly effectiveness ([microgel]/DOC) of marine samples was much higher than riverine. Instead of concentration of DOC, other factors such as types and sources of DOC polymers may control the microgel abundance in aquatic environments. After filtering water samples (microgels removed), the CDOM and selected metals (Cu, Ni, Mn) in the filtrate were quantified. CDOM and metals were concurrently removed to an extent via DOC polymer re-aggregation, which also suggested that the microgels had the sequestering capability in CDOM and metals. This finding provides an alternative route for CDOM and heavy metals removal from the water column. As such the process of re-aggregation into microgels should then be considered besides traditional phase partitioning in the assessment of the ecological risk and fate of pollutant.

Perforating Thin Metal Sheets

NASA Technical Reports Server (NTRS)

Davidson, M. E.

1985-01-01

Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

Microfluidic fuel cell systems with embedded materials and structures and method thereof

DOEpatents

Morse, Jeffrey D.; Rose, Klint A; Maghribi, Mariam; Benett, William; Krulevitch, Peter; Hamilton, Julie; Graff, Robert T.; Jankowski, Alan

2005-07-26

Described herein is a process for fabricating microfluidic systems with embedded components in which micron-scale features are molded into the polymeric material polydimethylsiloxane (PDMS). Micromachining is used to create a mold master and the liquid precursors for PDMS are poured over the mold and allowed to cure. The PDMS is then removed form the mold and bonded to another material such as PDMS, glass, or silicon after a simple surface preparation step to form sealed microchannels.

Aqueous processing of composite lithium ion electrode material

DOEpatents

Li, Jianlin; Armstrong, Beth L.; Daniel, Claus; Wood, III, David L.

2017-06-20

A method of making a battery electrode includes the steps of dispersing an active electrode material and a conductive additive in water with at least one dispersant to create a mixed dispersion; treating a surface of a current collector to raise the surface energy of the surface to at least the surface tension of the mixed dispersion; depositing the dispersed active electrode material and conductive additive on a current collector; and heating the coated surface to remove water from the coating.

Aqueous processing of composite lithium ion electrode material

DOEpatents

Li, Jianlin; Armstrong, Beth L; Daniel, Claus; Wood, III, David L

2015-02-17

A method of making a battery electrode includes the steps of dispersing an active electrode material and a conductive additive in water with at least one dispersant to create a mixed dispersion; treating a surface of a current collector to raise the surface energy of the surface to at least the surface tension of the mixed dispersion; depositing the dispersed active electrode material and conductive additive on a current collector; and heating the coated surface to remove water from the coating.

Treatment of halogen-containing waste and other waste materials

DOEpatents

Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

1997-01-01

A process for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes.

Treatment of halogen-containing waste and other waste materials

DOEpatents

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1997-03-18

A process is described for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes. 3 figs.

General purpose rocket furnace

NASA Technical Reports Server (NTRS)

Aldrich, B. R.; Whitt, W. D. (Inventor)

1979-01-01

A multipurpose furnace for space vehicles used for material processing experiments in an outer space environment is described. The furnace contains three separate cavities designed to process samples of the widest possible range of materials and thermal requirements. Each cavity contains three heating elements capable of independent function under the direction of an automatic and programmable control system. A heat removable mechanism is also provided for each cavity which operates in conjunction with the control system for establishing an isothermally heated cavity or a wide range of thermal gradients and cool down rates. A monitoring system compatible with the rocket telemetry provides furnace performance and sample growth rate data throughout the processing cycle.

Iron crystallization in a fluidized-bed Fenton process.

PubMed

Boonrattanakij, Nonglak; Lu, Ming-Chun; Anotai, Jin

2011-05-01

The mechanisms of iron precipitation and crystallization in a fluidized-bed reactor were investigated. Within the typical Fenton's reagent dosage and pH range, ferric ions as a product from ferrous ion oxidation would be supersaturated and would subsequently precipitate out in the form of ferric hydroxide after the initiation of the Fenton reaction. These precipitates would simultaneously crystallize onto solid particles in a fluidized-bed Fenton reactor if the precipitation proceeded toward heterogeneous nucleation. The heterogeneous crystallization rate was controlled by the fluidized material type and the aging/ripening period of the crystallites. Iron crystallization onto the construction sand was faster than onto SiO(2), although the iron removal efficiencies at 180 min, which was principally controlled by iron hydroxide solubility, were comparable. To achieve a high iron removal rate, fluidized materials have to be present at the beginning of the Fenton reaction. Organic intermediates that can form ferro-complexes, particularly volatile fatty acids, can significantly increase ferric ion solubility, hence reducing the crystallization performance. Therefore, the fluidized-bed Fenton process will achieve exceptional performance with respect to both organic pollutant removal and iron removal if it is operated with the goal of complete mineralization. Crystallized iron on the fluidized media could slightly retard the successive crystallization rate; thus, it is necessary to continuously replace a portion of the iron-coated bed with fresh media to maintain iron removal performance. The iron-coated construction sand also had a catalytic property, though was less than those of commercial goethite. Copyright © 2011 Elsevier Ltd. All rights reserved.

Removal of chloride from fly ash produced in hazardous waste incineration by leaching and displacement washing in a vertical filter press.

PubMed

Kinnarinen, Teemu; Huhtanen, Mikko; Penttilä, Mika; Häkkinen, Antti

2013-02-01

Fly ash is generated in large quantities by waste incineration processes. Chloride is commonly present in the fly ash produced by the incineration of hazardous materials, such as polyvinylchloride plastic. Major difficulties related to the disposal and handling of fly ash include the high concentration of easily leachable chlorides, heavy metals and toxic compounds. In order to avoid adverse environmental effects from the disposal of fly ash, the content of soluble chlorides must be reduced. One of the most effective options for chloride removal is leaching and displacement washing in a filter press. The primary aim of this study was to obtain efficient removal of chloride from fly ash by utilizing a leaching and displacement washing process, carried out in a filter press. The secondary objective was to obtain high filtration capacities and low filter cake moisture contents. The slurry was prepared by mixing fly ash with water at an ash:water ratio of 1:2 and filtered to separate the solids from the liquid. After solid-liquid separation, most of the dissolved residual chloride was removed from the filter cake by washing the cake with fresh water in the second stage of separation. It was possible to remove up to 98% of the total chloride and to obtain sufficient filtration capacities. The residual moisture content of the filter cakes varied from 22 to 35 wt%, which meant that the cakes could be disposed of in landfill, or possibly utilized as a construction material.

Selective dry etching of silicon containing anti-reflective coating

NASA Astrophysics Data System (ADS)

Sridhar, Shyam; Nolan, Andrew; Wang, Li; Karakas, Erdinc; Voronin, Sergey; Biolsi, Peter; Ranjan, Alok

2018-03-01

Multi-layer patterning schemes involve the use of Silicon containing Anti-Reflective Coating (SiARC) films for their anti-reflective properties. Patterning transfer completion requires complete and selective removal of SiARC which is very difficult due to its high silicon content (>40%). Typically, SiARC removal is accomplished through a non-selective etch during the pattern transfer process using fluorine containing plasmas, or an ex-situ wet etch process using hydrofluoric acid is employed to remove the residual SiARC, post pattern transfer. Using a non-selective etch may result in profile distortion or wiggling, due to distortion of the underlying organic layer. The drawbacks of using wet etch process for SiARC removal are increased overall processing time and the need for additional equipment. Many applications may involve patterning of active structures in a poly-Si layer with an underlying oxide stopping layer. In such applications, SiARC removal selective to oxide using a wet process may prove futile. Removing SiARC selectively to SiO2 using a dry etch process is also challenging, due to similarity in the nature of chemical bonds (Si - O) in the two materials. In this work, we present highly selective etching of SiARC, in a plasma driven by a surface wave radial line slot antenna. The first step in the process involves an in-situ modification of the SiARC layer in O2 plasma followed by selective etching in a NF3/H2 plasma. Surface treatment in O2 plasma resulted in enhanced etching of the SiARC layer. For the right processing conditions, in-situ NF3/H2 dry etch process demonstrated selectivity values greater than 15:1 with respect to SiO2. The etching chemistry, however, was sensitive to NF3:H2 gas ratio. For dilute NF3 in H2, no SiARC etching was observed. Presumably, this is due to the deposition of ammonium fluorosilicate layer that occurs for dilute NF3/H2 plasmas. Additionally, challenges involved in selective SiARC removal (selective to SiO2, organic and Si layers) post pattern transfer, in a multi-layer structure will be discussed.