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Sample records for cement production process

  1. [Release amount of heavy metals in cement product from co-processing waste in cement kiln].

    PubMed

    Yang, Yu-Fei; Huang, Qi-Fei; Zhang, Xia; Yang, Yu; Wang, Qi

    2009-05-15

    Clinker was produced by Simulating cement calcination test, and concrete samples were also prepared according to national standard GB/T 17671-1999. Long-term cumulative release amount of heavy metals in cement product from co-processing waste in cement kiln was researched through leaching test which refers to EA NEN 7371 and EA NEN 7375, and one-dimensional diffusion model which is on the base of Fick diffusion law. The results show that availabilities of heavy metals are lower than the total amounts in concrete. The diffusion coefficients of heavy metals are different (Cr > As > Ni > Cd). During 30 years service, the cumulative release amounts of Cr, As, Ni and Cd are 4.43 mg/kg, 0.46 mg/kg, 1.50 mg/kg and 0.02 mg/kg, respectively, and the ratios of release which is the division of cumulative release amount and availability are 27.0%, 18.0%, 3.0% and 0.2%, respectively. The most important influence factor of cumulative release amount of heavy metal is the diffusion coefficient, and it is correlative to cumulative release amount. The diffusion coefficient of Cr and As should be controlled exactly in the processing of input the cement-kiln. PMID:19558131

  2. Characteristics of mercury cycling in the cement production process.

    PubMed

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2016-01-25

    The mercury cycling caused by dust shuttling significantly increases the atmospheric emissions from cement production. A comprehensive understanding of this mercury cycling can promote the development of mercury emission control technologies. In this study, the characteristics of mercury cycling in the cement production process were first investigated. Furthermore, the mercury enrichment and effects of dust treatment were evaluated based on the field tests conducted in two Chinese cement plants. The mercury cycling between the kiln system and the raw mill system was the most important aspect and contributed 57-73% to the total amount of mercury emitted from the kiln system. Mercury emitted from the kiln system with flue gas was enriched as high as 3.4-8.8 times in the two tested plants compared to the amount of mercury in the raw materials and coal due to mercury cycling. The mercury enrichment can be significantly affected by the proportion of mercury cycled back to the kiln system. The effects of dust treatment were evaluated, and dust treatment can efficiently reduce approximately 31-70% of atmospheric mercury emissions in the two plants. The reduction proportion approximately linearly decreased with the proportion of mercury removed from the collected dust. PMID:26448491

  3. Sulfur cement production using by products of the perchloroethylene coal cleaning process and the FC4-1 cleaned soil

    SciTech Connect

    Bassam Masri, K.L.; Fullerton, S.L.

    1995-12-31

    An introductory set of experiments to show the feasibility of making sulfur cement were carried out at the University of Akron according to Parrett and Currett`s patent which requires the use of sulfur, a filler, a plasticizer, and a vulcanization accelerator. Small blocks of cement were made using byproducts of the perchloroethylene coal cleaning process. Extracted elemental and organic sulfur, ash and mineral matters from the float sink portion of the PCE process, and FC4-1 cleaned soil were used as substitutes for sulfur and filler needed for the production of sulfur cement. Leaching tests in different solutions and under different conditions were conducted on the sulfur blocks. Other tests such as strength, durability, resistance to high or low temperatures will be conducted in the future. Sulfur cement can be used as a sealing agent at a joint, roofing purposes, forming ornamental figures, and coating of exposed surfaces of iron or steel. When mixed with an aggregate, sulfur concrete is formed. This concrete can be used for structural members, curbings, guthers, slabs, and can be precast or cast at the job site. An advantage of sulfur cement over Portland cement is that it reaches its design strength in two to three hours after processing and it can be remelted and recast.

  4. Process for cementing a well

    SciTech Connect

    Cowan, K.M.; Hale, A.H.

    1991-06-04

    This paper describes a process for cementing a casing in a borehole of a well. It comprises: preparing an aqueous cement slurry containing a sufficient amount of a selected water soluble polyalcohol having from 2 to 18 carbon atoms and 2 to 13 hydroxyl groups, the concentration of polyalcohol in the water used to prepare and set the slurry being about 0.01 to about 5% by volume, the selection of the polyalcohol being restricted to a polyalcohol which functions to promote a more fluid-tight seal and better mechanical shear bond between the cement and surfaces contacting the cement; and injecting the cement slurry into the well between the casing and the borehole.

  5. Alternative Fuel for Portland Cement Processing

    SciTech Connect

    Anton K. Schindler; Steve R. Duke; Thomas E. Burch; Edward W. Davis; Ralph H. Zee; David I. Bransby; Carla Hopkins; Rutherford L. Thompson; Jingran Duan; Vignesh Venkatasubramanian; Stephen Giles.

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted at a full-scale cement plant with alternative fuels to examine their compatibility with the cement production process. Construction and demolition waste, woodchips, and soybean seeds were used as alternative fuels at a full-scale cement production facility. These fuels were co-fired with coal and waste plastics. The alternative fuels used in this trial accounted for 5 to 16 % of the total energy consumed during these burns. The overall performance of the portland cement produced during the various trial burns performed for practical purposes very similar to the cement produced during the control burn. The cement plant was successful in implementing alternative fuels to produce a consistent, high-quality product that increased cement performance while reducing the environmental footprint of the plant. The utilization of construction and demolition waste, woodchips and soybean seeds proved to be viable replacements for traditional fuels. The future use of these fuels depends on local availability, associated costs, and compatibility with a facility’s production process.

  6. Principles of technological design of wasteless chemical processes based on the use of wastes for production of alkaline slag cements and concretes

    SciTech Connect

    Glukhovskii, V.D.; Chernobaev, I.P.; Emel'yanov, B.M.; Semenyuk, A.P.

    1985-05-20

    The strength characteristics of alkaline slag-cement made with the use of waste from alkaline sealing of metals are presented. The cement was prepared from granulated blast-furnance slag with average component contents in the following ranges (mass %): SiO/sub 2/ 36.0-40.2, Al/sub 2/O/sub 3/ 4-18.2, FeO 0.1-3.7, MnO 0.4-5.2, CaO 33.1-48.8, MgO 2.2-9.8. With the use of wastes from the descaling process in alkali melts for production of alkaline slag cements it is possible to obtain highly effective cements of type 700-900, which is 2 to 3 times the value for portland cements. Therefore, the use of wastes from alkaline descaling for production of alkaline slag cements is of great economic and conservational significance. It is possible to devise a wasteless process of scale removal from metals; this is an important advantage of the alkaline scaling method over acid pickling.

  7. [Environment load from China's cement production].

    PubMed

    Zhu, Tian-le; He, Wei; Zeng, Xiao-lan; Huang, Xin; Ma, Bao-guo

    2006-10-01

    Based on the life-cycle theory, a quantitative evaluation of the environment load caused by cement manufacturing in China was carried out with the application of the CML. environmental impact assessment method. The results show that global warming potential, energy depletion potential and abiotic depletion potential make the main contribution to the environment impact, their environmental loads corresponding to identical environmental impact sorts being 2.76%, 2.34% and 1.39% of the overall load of the whole world, respectively. In 2004, the environment load from cement manufacturing in China is roughly 1.28% of the overall load of the whole world, in which the environmental loads from the shaft kiln processing, wet rotary processing and new-type dry processing being 0.84%, 0.12% and 0.32%, respectively. And it can be reduced to about 1% by replacing backward production processes with the dry method production process. PMID:17256624

  8. Identifying improvement potentials in cement production with life cycle assessment.

    PubMed

    Boesch, Michael Elias; Hellweg, Stefanie

    2010-12-01

    Cement production is an environmentally relevant process responsible for 5% of total anthropogenic carbon dioxide emissions and 7% of industrial fuel use. In this study, life cycle assessment is used to evaluate improvement potentials in the cement production process in Europe and the USA. With a current fuel substitution rate of 18% in Europe and 11% in the USA, both regions have a substantial potential to reduce greenhouse gas emissions and save virgin resources by further increasing the coprocessing of waste fuels. Upgrading production technology would be particularly effective in the USA where many kiln systems with very low energy efficiency are still in operation. Using best available technology and a thermal substitution rate of 50% for fuels, greenhouse gas emissions could be reduced by 9% for Europe and 18% for the USA per tonne of cement. Since clinker production is the dominant pollution producing step in cement production, the substitution of clinker with mineral components such as ground granulated blast furnace slag or fly ash is an efficient measure to reduce the environmental impact. Blended cements exhibit substantially lower environmental footprints than Portland cement, even if the substitutes feature lower grindability and require additional drying and large transport distances. The highest savings in CO(2) emissions and resource consumption are achieved with a combination of measures in clinker production and cement blending. PMID:21047057

  9. Process for cementing geothermal wells

    SciTech Connect

    Eilers, L. H.

    1985-12-03

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight monoor copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  10. Process for cementing geothermal wells

    DOEpatents

    Eilers, Louis H.

    1985-01-01

    A pumpable slurry of coal-filled furfuryl alcohol, furfural, and/or a low molecular weight mono- or copolymer thereof containing, preferably, a catalytic amount of a soluble acid catalyst is used to cement a casing in a geothermal well.

  11. Production of hydraulic cements and cement-forming materials

    SciTech Connect

    Tylko, J.

    1980-07-29

    Apparatus for the production of hydraulic cements and pozzolanic materials comprising means for mixing and blending a calcareous material and a carbonaceous material containing silica, means for drying and grinding such blend to a comminuted condition, means for supplying hot gas to said drying and grinding means, a plasma reactor of the type in which at least one plasma gun orbits about a substantially vertical axis and is directed obliquely to said vertical axis and towards an opposed counter-electrode, said reactor including means for supplying a curtain of comminuated material to a cone of expanded precessive plasma developed within said plasma reactor, a feed preheater arranged between said drying and grinding means and said supplying means, granulating means for granulating material emerging from said plasma zone, means for passing a stream of air successively through said granulating means, said feed preheater and said feed drying and grinding means, a waste-heat boiler for recovery of heat energy released in the combustion of the calorific values of the carbonaceous material and means for generating electricity by use of the recovered thermal energy.

  12. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    PubMed Central

    Yang, Yufei; Xue, Jingchuan; Huang, Qifei

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4. PMID:24223030

  13. Control of structurization processes in wood-cement systems at fixed pH

    NASA Astrophysics Data System (ADS)

    Subbotina, Natalia; Gorlenko, Nikolay; Sarkisov, Yuriy; Naumova, Ludmila; Minakova, Tamara

    2016-01-01

    The paper presents a study of structurization processes in the wood-cement systemmixed with the buffer solutions and the improvement of service properties of products produced therefrom. Infrared spectroscopy, X-ray phase analysis, and pH measurements show that structurization processes in wood-cement systems depend on the acidity of aqueous solution, the behavior of hydration, neutralization, and polycondensation reactions with the formation of polymer products including those with cement grout components and functional groups of wood. It is shown that phosphate buffer solutions used for mixing wood-cement compositions improve their strength properties and reduce water absorption. The optimum acidity of the buffered medium for service properties of the wood-cement systemis pH = 4.8.

  14. Sustainable cement production-present and future

    SciTech Connect

    Schneider, M.; Romer, M.; Tschudin, M.; Bolio, H.

    2011-07-15

    Cement will remain the key material to satisfy global housing and modern infrastructure needs. As a consequence, the cement industry worldwide is facing growing challenges in conserving material and energy resources, as well as reducing its CO{sub 2} emissions. According to the International Energy Agency, the main levers for cement producers are the increase in energy efficiency and the use of alternative materials, be it as fuel or raw materials. Accordingly, the use of alternative fuels has already increased significantly in recent years, but potential for further increases still exists. In cement, the reduction of the clinker factor remains a key priority: tremendous progress has already been made. Nevertheless, appropriate materials are limited in their regional availability. New materials might be able to play a role as cement constituents in the future. It remains to be seen to what extent they could substitute Portland cement clinker to a significant degree.

  15. Use of MRF residue as alternative fuel in cement production.

    PubMed

    Fyffe, John R; Breckel, Alex C; Townsend, Aaron K; Webber, Michael E

    2016-01-01

    Single-stream recycling has helped divert millions of metric tons of waste from landfills in the U.S., where recycling rates for municipal solid waste are currently over 30%. However, material recovery facilities (MRFs) that sort the municipal recycled streams do not recover 100% of the incoming material. Consequently, they landfill between 5% and 15% of total processed material as residue. This residue is primarily composed of high-energy-content non-recycled plastics and fiber. One possible end-of-life solution for these energy-dense materials is to process the residue into Solid Recovered Fuel (SRF) that can be used as an alternative energy resource capable of replacing or supplementing fuel resources such as coal, natural gas, petroleum coke, or biomass in many industrial and power production processes. This report addresses the energetic and environmental benefits and trade-offs of converting non-recycled post-consumer plastics and fiber derived from MRF residue streams into SRF for use in a cement kiln. An experimental test burn of 118Mg of SRF in the precalciner portion of the cement kiln was conducted. The SRF was a blend of 60% MRF residue and 40% post-industrial waste products producing an estimated 60% plastic and 40% fibrous material mixture. The SRF was fed into the kiln at 0.9Mg/h for 24h and then 1.8Mg/h for the following 48h. The emissions data recorded in the experimental test burn were used to perform the life-cycle analysis portion of this study. The analysis included the following steps: transportation, landfill, processing and fuel combustion at the cement kiln. The energy use and emissions at each step is tracked for the two cases: (1) The Reference Case, where MRF residue is disposed of in a landfill and the cement kiln uses coal as its fuel source, and (2) The SRF Case, in which MRF residue is processed into SRF and used to offset some portion of coal use at the cement kiln. The experimental test burn and accompanying analysis indicate that using MRF residue to produce SRF for use in cement kilns is likely an advantageous alternative to disposal of the residue in landfills. The use of SRF can offset fossil fuel use, reduce CO2 emissions, and divert energy-dense materials away from landfills. For this test-case, the use of SRF offset between 7700 and 8700Mg of coal use, reduced CO2 emissions by at least 1.4%, and diverted over 7950Mg of energy-dense materials away from landfills. In addition, emissions were reduced by at least 19% for SO2, while NOX emissions increased by between 16% and 24%. Changes in emissions of particulate matter, mercury, hydrogen chloride, and total-hydrocarbons were all less than plus or minus 2.2%, however these emissions were not measured at the cement kiln. Co-location of MRFs, SRF production facilities, and landfills can increase the benefits of SRF use even further by reducing transportation requirements. PMID:26187294

  16. STUDY OF AMMONIA SOURCE AT A PORTLAND CEMENT PRODUCTION PLANT (JOURNAL VERSION)

    EPA Science Inventory

    A source and process sampling study was conducted at a dry process Portland Cement production plant. One aspect of the study focused on the source or point of NH3 within the production process. An extensive number of process solids from raw feeds to baghouse solids were collected...

  17. Cementing: A systematic approach

    SciTech Connect

    Sauer, C.W.; Landrum, W.R.

    1983-10-01

    A step-by-step approach in the form of a cementing process design chart, has been developed for use in Conoco's operating divisions worldwide. The design chart described in this paper includes cement and additive selection and associated hardware for casing and liner cementing operations. Each type of cementing operation is designed to insure the compatibility of hardware and cement slurry components. The process design chart is separated into two major categories: primary cementing; and liner cementing. These categories are separated further into design criteria for cementing each casing string in a well, conductor pipe through production string and each type of liner that is set. Conoco has realized reduced primary cementing costs, up to $35,000.00 per well in some cases, and fewer remedial cement jobs as a result of using practices included in this process design chart. These cost savings can be attributed to the proper cementing practices from many geographic regions which are consolidated into this easy to use cementing design chart. One example of how cement costs can be reduced is by limiting the amount of expensive synthetic cement additives that have been added to less critical pipe strings. These expensive cement additives have been replaced by less expensive natural cement additives that perform just as well, and have resulted in a reduction in the cost per cubic foot of cement slurry.

  18. Follow up study of workers manufacturing chrysotile asbestos cement products.

    PubMed Central

    Gardner, M J; Winter, P D; Pannett, B; Powell, C A

    1986-01-01

    A cohort study has been carried out of 2167 subjects employed between 1941 and 1983 at an asbestos cement factory in England. The production process incorporated the use of chrysotile asbestos fibre only, except for a small amount of amosite during four months in 1976. Measured airborne fibre concentrations available since 1970 from personal samplers showed mean levels below 1 fibre/ml, although higher levels had probably occurred previously in certain areas of the factory. No excess of lung cancer was observed in the mortality follow up by comparison with either national or local death rates, and analyses of subgroups of the workforce by job, exposure level, duration of employment, duration since entry, or calendar years of employment gave no real suggestion of an asbestos related excess for this cause of death. There was one death from pleural mesothelioma and one with asbestosis mentioned as an associated cause on the death certificate, but neither is thought to be linked to asbestos exposure at this factory. Other suggested asbestos related cancers, such as laryngeal and gastrointestinal, did not show raised risks. Although the durations of exposure were short in this study, the findings are consistent with two other studies of workers exposed to low concentrations of chrysotile fibre in the manufacture of asbestos cement products which reported no excess mortality. PMID:3024695

  19. Cementation process for minerals recovery from Salton Sea geothermal brines

    SciTech Connect

    Maimoni, A.

    1982-01-26

    The potential for minerals recovery from a 1000-MWe combined geothermal power and minerals recovery plant in the Salton Sea is examined. While the possible value of minerals recovered would substantially exceed the revenue from power production, information is insufficient to carry out a detailed economic analysis. The recovery of precious metals - silver, gold, and platinum - is the most important factor in determining the economics of a minerals recovery plant; however, the precious metals content of the brines is not certain. Such a power plant could recover 14 to 31% of the US demand for manganese and substantial amounts of zinc and lead. Previous work on minerals extraction from Salton Sea brines is also reviewed and a new process, based on a fluidized-bed cementation reaction with metallic iron, is proposed. This process would recover the precious metals, lead, and tin present in the brines.

  20. Carbon dioxide capture from a cement manufacturing process

    SciTech Connect

    Blount, Gerald C.; Falta, Ronald W.; Siddall, Alvin A.

    2011-07-12

    A process of manufacturing cement clinker is provided in which a clean supply of CO.sub.2 gas may be captured. The process also involves using an open loop conversion of CaO/MgO from a calciner to capture CO.sub.2 from combustion flue gases thereby forming CaCO.sub.3/CaMg(CO.sub.3).sub.2. The CaCO.sub.3/CaMg(CO.sub.3).sub.2 is then returned to the calciner where CO.sub.2 gas is evolved. The evolved CO.sub.2 gas, along with other evolved CO.sub.2 gases from the calciner are removed from the calciner. The reactants (CaO/MgO) are feed to a high temperature calciner for control of the clinker production composition.

  1. Characterization of vapor phase mercury released from concrete processing with baghouse filter dust added cement.

    PubMed

    Wang, Jun; Hayes, Josh; Wu, Chang-Yu; Townsend, Timothy; Schert, John; Vinson, Tim; Deliz, Katherine; Bonzongo, Jean-Claude

    2014-02-18

    The fate of mercury (Hg) in cement processing and products has drawn intense attention due to its contribution to the ambient emission inventory. Feeding Hg-loaded coal fly ash to the cement kiln introduces additional Hg into the kiln's baghouse filter dust (BFD), and the practice of replacing 5% of cement with the Hg-loaded BFD by cement plants has recently raised environmental and occupational health concerns. The objective of this study was to determine Hg concentration and speciation in BFD as well as to investigate the release of vapor phase Hg from storing and processing BFD-added cement. The results showed that Hg content in the BFD from different seasons ranged from 0.91-1.44 mg/kg (ppm), with 62-73% as soluble inorganic Hg, while Hg in the other concrete constituents were 1-3 orders of magnitude lower than the BFD. Up to 21% of Hg loss was observed in the time-series study while storing the BFD in the open environment by the end of the seventh day. Real-time monitoring in the bench system indicated that high temperature and moisture can facilitate Hg release at the early stage. Ontario Hydro (OH) traps showed that total Hg emission from BFD is dictated by the air exchange surface area. In the bench simulation of concrete processing, only 0.4-0.5% of Hg escaped from mixing and curing BFD-added cement. A follow-up headspace study did not detect Hg release in the following 7 days. In summary, replacing 5% of cement with the BFD investigated in this study has minimal occupational health concerns for concrete workers, and proper storing and mixing of BFD with cement can minimize Hg emission burden for the cement plant. PMID:24444016

  2. Aluminum dross oxide products for the portland cement industry

    SciTech Connect

    Zuck, D.A.

    1995-12-31

    Recovery of aluminum metal from drosses is a major factor in the recyclability success story enjoyed by the United States aluminum industry. Today`s modern dross processor uses the latest technology to maximize metal recovery at the lowest cost while complying with all environmental laws and regulations. Most dross processors, however, pay little attention to the resulting saltcake, the end residual of dross recycling, and rely on landfills for disposition of this material. The alternative is to recycle the saltcake, but the success of this technology is dependent on the development of reliable outlets for each of the saltcake constituents. This paper discusses the evolution of an aluminum dross oxide processing technology that produces an economically attractive source of alumina for the production of portland cement.

  3. Production of cements from Illinois coal ash. Technical report, September 1, 1995--November 30, 1995

    SciTech Connect

    Wagner, J.C.; Bhatty, J.I.; Mishulovich, A.

    1995-12-31

    The objective of this program is to convert Illinois coal combustion residues, such as fly ash, bottom ash, and boiler slag, into novel cementitious materials for use in the construction industry. Currently only about 30% of the 5 million tons of these coal combustion residues generated in Illinois each year are utilized, mainly as aggregate. These residues are composed largely Of SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, MgO, and CaO, which are also the major components of cement. The process being developed in this program will use the residues directly in the manufacture of cement products. Therefore, a much larger amount of residues can be utilized. To achieve the above objective, in the first phase (current year) samples of coal combustion residues will be blended and mixed, as needed, with a lime or cement kiln dust (CKD) to adjust the CaO composition. Six mixtures will be melted in a laboratory-scale furnace at CTL. The resulting products will then be tested for cementitious properties. Two preliminary blends have been tested. One blend used fly ash with limestone, while the other used fly ash with CKD. Each blend was melted and then quenched, and the resulting product samples were ground to a specific surface area similar to portland cement. Cementitious properties of these product samples were evaluated by compression testing of 1-inch cube specimens. The specimens were formed out of cement paste where a certain percentage of the cement paste is displaced by one of the sample products. The specimens were cured for 24 hours at 55{degrees}C and 100% relative humidity. The specimens made with the product samples obtained 84 and 89% of the strength of a pure portland cement control cube. For comparison, similar (pozzolanic) materials in standard concrete practice are required to have a compressive strength of at least 75% of that of the control.

  4. Physico-chemical characteristics of cement produced using sulfur bearing fuels in the black meal process for cement manufacture

    SciTech Connect

    Barkakati, P.; Bordoloi, D.; Bandyopadhyay, S.; Borah, U.C. )

    1993-09-01

    Assam coal containing 2-6% sulfur and around 40% volatiles can be used for making quality cement in the black meal process for cement manufacture using the Vertical Shaft Kiln (VSK) technology. It is observed that the use of these sulfur bearing fuels need little modification in the operational parameters of the VSK. The chemical, mineralogical and physical properties of the clinker/cement produced using Assam coal as fuel in the above process are provided. The clinkers generated with sulfur bearing coals are studied and probable reasons for obtaining quality cement even with an SO[sub 3] content of more than 3% in the clinkers are discussed.

  5. India's cement industry: Productivity, energy efficiency and carbon emissions

    SciTech Connect

    Schumacher, Katja; Sathaye, Jayant

    1999-07-01

    Historical estimates of productivity growth in India's cement sector vary from indicating an improvement to a decline in the sector's productivity. The variance may be traced to the time period of study, source of data for analysis, and type of indices and econometric specifications used for reporting productivity growth. Analysis shows that in the twenty year period, 1973 to 1993, productivity in the aluminum sector increased by 0.8% per annum. An econometric analysis reveals that technical progress in India's cement sector has been biased towards the use of energy and capital, while it has been material and labor saving. The increase in productivity was mainly driven by a period of progress between 1983 and 1991 following partial decontrol of the cement sector in 1982. The authors examine the current changes in structure and energy efficiency in the sector. Their analysis shows that the Indian cement sector is moving towards world-best technology, which will result in fewer carbon emissions and more efficient energy use. However, substantial further energy savings and carbon reduction potentials still exist.

  6. Effects of prosthesis surface roughness on the failure process of cemented hip implants after stem-cement debonding.

    PubMed

    Verdonschot, N; Tanck, E; Huiskes, R

    1998-12-15

    Retrieval studies suggest that the loosening process of the cemented femoral components of total hip arthroplasties is initiated by failure of the bond between the prosthesis and the cement mantle. Finite element (FE) analyses have demonstrated that stem-cement debonding has stress-producing effects in the cement mantle. High interface friction, which corresponds to a degree of surface roughness, reduces these stresses. In experiments, however, debonded rough stems produced more cement damage than polished ones; in the Swedish Hip Register polished stems were clinically superior with respect to stems with a mat surface finish. The purpose of the present study was to investigate this contradiction. For this purpose, global and local FE models with debonded stem-cement interfaces were used to study the effects of prosthesis surface roughness on the cement stresses on a global scale and microscale, respectively. Similar to earlier numerical studies, the global FE model predicted that an increased surface roughness of the stem reduced the stresses in the cement mantle. The local model provided insight in the load-transfer mechanism on a microscale and could explain the experimental and clinical findings. The local cement peak stresses around the asperities of the surface roughness profile increased with increasing surface roughness and decreased again beyond a particular roughness value. Cement abrasion is caused by localized stresses in combination with micromotion. From this study it can be concluded that to minimize cement abrasion, debonded stems should either have a polished microstructure to minimize the local cement stresses or have a profiled macrostructure to minimize micromotions at the stem-cement interface. PMID:9827679

  7. Glass recycling in cement production--an innovative approach.

    PubMed

    Chen, Guohua; Lee, Harry; Young, King Lun; Yue, Po Lock; Wong, Adolf; Tao, Thomas; Choi, Ka Keung

    2002-01-01

    An innovative approach of using waste glass in cement production was proposed and tested in a laboratory and cement production plant. The laboratory characterization of 32 types of glass show that the chemical composition of glass does not vary significantly with its color or origin but depends on its application. The alkali content of glass, a major concern for cement production varies from 0 to 22%. For the glass bottles mainly found in Hong Kong waste glasses, the alkali content (Na2O) ranges from 10 to 19% with an average around 15%. There is no significant change of the SO2 content in the gas exhaust of the rotary kiln when about 1.8 t/h of glass bottles were loaded along with the 280-290 t/h raw materials. The content of NOx, mainly depends on the temperature of the kiln, does not show significant change either. The SO3 content of the clinker is comparable with that obtained without the loading of glass. The alkaline content shows a slight increase but still within three times the standard deviation obtained from the statistical data of the past year. The detailed analysis of the quality of the cement product shows that there is not any significant impact of glass for the feeding rate tested. PMID:12365777

  8. Influence of the processed sunflower oil on the cement properties

    NASA Astrophysics Data System (ADS)

    Fleysher, A. U.; Tokarchuk, V. V.; Sviderskiy, V. A.

    2015-01-01

    Used oils (vegetable oil, animal oil, engine oil, etc.), which are essentially industrial wastes, have found application as secondary raw materials in some braches of industry. In particular, the only well-known and commonly-used way of utilizing wastes of vegetable oils is to apply them as raw materials in the production of biodiesel. The goal of the present study is to develop a conceptually new way of vegetable oil wastes utilization in the building industry. The test admixture D-148 was obtained from the processing of wastes of sunflower oil and it mainly consists of fatty acid diethanolamide. The test admixture was added to the cement system for the purpose of studying its influence on water demand, flowability, setting times, compressive strength and moisture adsorption. The test admixture D-148 at the optimal content 0. 2 weight % causes 10% decrease in water demand, 1.7 time increase in flowability (namely spread diameter), 23% increase in grade strength and 34% decrease in moisture adsorption. The results of the present investigation make it possible to consider the final product of the waste sunflower oil processing as multifunctional plasticizing-waterproofing admixture.

  9. Evaluation of cement production using a pressurized fluidized-bed combustor

    SciTech Connect

    DeLallo, M.; Eshbach, R.

    1994-01-01

    There are several primary conclusions which can be reached and used to define research required in establishing the feasibility of using PFBC-derived materials as cement feedstock. 1. With appropriate blending almost any material containing the required cement-making materials can be utilized to manufacture cement. However, extensive blending with multiple materials or the use of ash in relatively small quantities would compromise the worth of this concept. 2. The composition of a potential feedstock must be considered not only with respect to the presence of required materials, but just as significantly, with respect to the presence and concentration of known deleterious materials. 3. The processing costs for rendering the feedstock into an acceptable composition and the energy costs associated with both processing and burning must be considered. It should be noted that the cost of energy to produce cement, expressed as a percentage of the price of the product is higher than for any other major industrial product. Energy consumption is, therefore, a major issue. 4. The need for conformance to environmental regulations has a profound effect on the cement industry since waste materials can neither be discharged to the atmosphere or be shipped to a landfill. 5. Fifth, the need for achieving uniformity in the composition of the cement is critical to controlling its quality. Unfortunately, certain materials in very small concentrations have the capability to affect the rate and extent to which the cementitious compound in portland cement are able to form. Particularly critical are variations in the ash, the sulfur content of the coal or the amount and composition of the stack dust returned to the kiln.

  10. [Comparison of fixation effects of heavy metals between cement rotary kiln co-processing and cement solidification/stabilization].

    PubMed

    Zhang, Jun-li; Liu, Jian-guo; Li, Cheng; Jin, Yi-ying; Nie, Yong-feng

    2008-04-01

    Both cement rotary kiln co-processing hazardous wastes and cement solidification/stabilization could dispose heavy metals by fixation. Different fixation mechanisms lead to different fixation effects. The same amount of heavy metal compounds containing As, Cd, Cr, Cu, Pb, Zn were treated by the two kinds of fixation technologies. GB leaching test, TCLP tests and sequential extraction procedures were employed to compare the fixation effects of two fixation technologies. The leached concentration and chemical species distribution of heavy metals in two grounded mortar samples were analyzed and the fixation effects of two kinds of technologies to different heavy metals were compared. The results show the fixation effect of cement rotary kiln co-processing technology is better than cement solidification/stabilization technology to As, Pb, Zn. Calcinations in cement rotary kiln and then hydration help As, Pb, Zn contained in hazardous wastes transform to more steady chemical species and effectively dispose these heavy metals compounds. Cr3+ is liable to be converted to much more toxic and more mobile Cr6+ state in cement rotary kiln. And so Cr wastes are more fit for treatment by cement solidification/stabilization technology. The work could provide a basis when choosing disposal technologies for different heavy metals and be helpful to improve the application and development of cement rotary kiln co-processing hazardous wastes. PMID:18637375

  11. Flushed zone process helps control gas migration in primary cementing

    SciTech Connect

    Teichrob, R.R. )

    1993-08-16

    Gas migration during cementing operations can be eliminated with optimal drilling practices and ultra-high filtrate loss drilling fluids or properly designed squeeze fluids. A method based on the flushed zone theory involves squeezing fluid into a potential gas-bearing formation to reduce the permeability to gas near the well bore. The process aims to suppress gas flow long enough for the cement to set. The process is accomplished in the following way: the well is drilled to a predetermined depth and all inhibited drilling fluids in the well are displaced by an appropriate squeeze fluid. The annulus is packed off and pressure is applied down the drill pipe. The volume of squeeze fluid pumped away is monitored, and the flush volume is estimated based on assumed permeability, porosity, and interval height. Once the squeeze fluid volume is pumped away, the remaining fluid is displaced back to surface with the original mud system. Drilling resumes, and the well is drilled to total depth, logged, and then abandoned or cased. As the hydrostatic pressure imposed by liquid cement decreases as a function of gel strength development, the altered permeability of adjacent gas-bearing intervals precludes gas movement into the setting cement. The concept behind the flushed zone theory is basic: the gas is moved radially away from the well bore face, and because the formation's permeability to gas changes, the gas is kept away at least long enough to drill, log, and case the zone. Because the residual effects of reduced permeability to gas are unknown, cement permeability to gas in itself may play an important role in long-term solutions to controlling migrating gases through micro-annuli.

  12. Well cementing process using presheared water swellable clays

    SciTech Connect

    Messenger, J.U.

    1980-05-13

    A method of preparing and using a cement slurry having water swellable clays therein as extenders for the cement is described. This method enhances the effectiveness of the water swellable clays by preshearing aqueous suspensions thereof prior to mixing these suspensions with cement to form a pumpable cement slurry. Also described is a particular technique for using bentonite as a cement extender in a cement slurry formed with salt water.

  13. Hazardous waste incineration in industrial processes: cement and lime kilns

    SciTech Connect

    Mournighan, R.E.; Peters, J.A.; Branscome, M.R.; Freeman, H.

    1985-07-01

    With more liquid wastes due to be banned from land disposal facilities, expanding hazardous waste incineration capacity becomes increasingly important. At the same time, industrial plants are increasingly seeking to find new sources of lower cost fuel, specifically from the disposal of hazardous wastes with heating value. The Hazardous Waste Engineering Research Laboratory (HWERL) is currently evaluating the disposal of hazardous wastes in a wide range of industrial processes. The effort includes sampling stack emissions at cement, lime and aggregate plants, asphalt plants and blast furnaces, which use waste as a supplemental fuel. This research program is an essential part of EPA's determination of the overall environmental impact of various disposal options available to industry. This paper summarizes the results of the HWERL program of monitoring emissions from cement and lime kilns burning hazardous wastes as fuel.

  14. Catalytic behavior of graphene oxide for cement hydration process

    NASA Astrophysics Data System (ADS)

    Lin, Changqing; Wei, Wei; Hu, Yun Hang

    2016-02-01

    Hydration is a critical step that determines the performance of cement-based materials. In this paper, the effect of GO on the hydration of cement was evaluated by XRD and FTIR. It was found that GO can remarkably accelerate the hydration rate of cement due to its catalytic behavior. This happened because the oxygen-containing functional groups of GO provide adsorption sites for both water molecules and cement components.

  15. Emerging Energy-efficiency and CO{sub 2} Emission-reduction Technologies for Cement and Concrete Production

    SciTech Connect

    Hasanbeigi, Ali; Price, Lynn; Lin, Elina

    2012-04-06

    Globally, the cement industry accounts for approximately 5 percent of current anthropogenic carbon dioxide (CO{sub 2}) emissions. World cement demand and production are increasing significantly, leading to an increase in this industry's absolute energy use and CO{sub 2} emissions. Development of new energy-efficiency and CO{sub 2} emission-reduction technologies and their deployment in the market will be key for the cement industry's mid- and long-term climate change mitigation strategies. This report is an initial effort to compile available information on process description, energy savings, environmental and other benefits, costs, commercialization status, and references for emerging technologies to reduce the cement industry's energy use and CO{sub 2} emissions. Although studies from around the world identify a variety of sector-specific and cross-cutting energy-efficiency technologies for the cement industry that have already been commercialized, information is scarce and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on nineteen emerging technologies for the cement industry, with the goal of providing engineers, researchers, investors, cement companies, policy makers, and other interested parties with easy access to a well-structured database of information on these technologies.

  16. System for radioactive waste cementation

    SciTech Connect

    Dmitriev, S.A.; Barinov, A.S.; Varlakov, A.P.; Volkov, A.S.; Karlin, S.V.

    1995-12-31

    NPP, research reactors and radiochemical enterprises produce a great amount of liquid radioactive waste (LRW). One of the methods of LRW solidification is cementation. The recent investigations demonstrated possible inclusion of sufficient amount of waste in the cement matrix (up to 20--30 mass% on dry residue). In this case the cementation process becomes competitive with bituminization process, where the matrix can include 40--50 mass% and the solidified product volume is equal to the volume, obtained by cementation. Additionally, the cement matrix in contrast with the bituminous one is unburnable. Many countries are investigating the cementation process. The main idea governing technological process is the waste and cement mixing method and type of mixer. In world practice some principal types of cementation systems are used. The paper describes the SIA Radon industrial plant in Moscow.

  17. Feasibility of using reject fly ash in cement-based stabilization/solidification processes

    SciTech Connect

    Poon, C.S.; Qiao, X.C.; Cheeseman, C.R.; Lin, Z.S.

    2006-01-15

    Stabilization/solidification (s/s) has been routinely used for the final treatment of hazardous wastes prior to land disposal. These processes involve adding one or more solidifying reagents into the waste to transform it into a monolithic solid with improved structural integrity. Cement-based systems with partial replacement by pulverized fuel ash (PFA) have been widely used to minimize leaching of contaminants from hazardous wastes. The finer fraction of PFA ({lt}45 {mu} m, fine fly ash, MA), produced by passing the raw ash through a classifying process is commonly used in s/s processes. Low-grade fly ash is rejected (rFA) from the ash classifying process, and is largely unused due to high carbon content and large particle size but represents a significant proportion of PFA. This paper presents experimental results of a study that has assessed the feasibility of using rFA in the cement-based s/s of a synthetic heavy metal waste. Results were compared to mixes containing fFA. The strength results show that cement-based waste forms with rFA replacement are suitable for disposal at landfill and that the addition of heavy metal sludge can increase the degree of hydration of fly ash and decrease the porosity of samples. Adding Ca(OH){sub 2} and flue gas desulphurization sludge reduces the retarding effect of heavy metals on strength development. The results of the Toxicity Characteristic Leaching Procedure and Dynamic Leach Test show that rFA can be used in cement-based s/s wastes without compromising performance of the product.

  18. DEVELOPMENT OF A POLYMERIC CEMENTING AND ENCAPSULATING PROCESS FOR MANAGING HAZARDOUS WASTES

    EPA Science Inventory

    A process using polymeric materials to cement and encapsulate dry hazardous waste was researched, developed, and evaluated. The process involves cementing particulates of waste into 500 to 1000 pound agglomerates, and then fusing a plastic jacket onto the agglomerate surfaces, th...

  19. Improved control of the finish grinding process in cement manufacture

    SciTech Connect

    Menacho, J.M.; Austin, L.G.; Cuhadaroglu, M.S. . Dept. of Mineral Processing)

    1985-01-01

    Activities developed on Task 6 of the Cement Clinker Project from July 1, 1985 to September 30, 1985 are described in this progress report. Results on eight continuous ball mill tests are included. Experimentation was performed in a 0.99 m diameter air-swept mill at the Kennedy Van Saun facilities in Danville. In the first four runs, the effect of production rate on size distribution of product was tested for the powder filling level around 0.83. In the other tests, the powder filling was changed between 0.7 and 1.25. A preliminary analysis of the results indicates that the internal classification curve is moving in a narrow band even when the product size distribution is strongly affected by the different experimented condition. Also the direct scale-up results from the 8 inch diameter batch mill to the 0.99 mill diameter in batch mode is reported. Predictions overestimate capacity for short times of grinding but they are in good agreement for long times. The presence of components having large and small rate of breakage and occurrence of abnormal breakage are discussed. Future work includes detailed analysis of the data and simulation of continuous test results.

  20. ASBESTOS-CEMENT PRODUCTS IN CONTACT WITH DRINKING WATER: SEM OBSERVATIONS

    EPA Science Inventory

    In studying the health effects of asbestos fibers ingested in drinking water it is important to know whether water can corrode the surface of asbestos-cement products to facilitate the release of the fibers to the water. Also, in the case of asbestos-cement pipe, it is important ...

  1. Up to 80% reduction of CO{sub 2} greenhouse gas emission during cement manufacture. Geology provides very low-CO{sub 2} cement production technology

    SciTech Connect

    Davidovits, J.; Rocher, P.; Davidovits, F.; Gimeno, D.; Marini, C.; Toco, S.

    1996-12-31

    European cement manufacturers are confronted with the EC CO{sub 2} eco-tax proposal and are lobbying Brussel`s Administration. They claim that the eco-tax would have a negative effect on the competitiveness of the European cement industry. Development means building infrastructures and houses; in short cement and concrete. The stage of any national economic development is judged by the growth rate of infrastructures which is linked to the cement production. Due to the exponential use of concrete, cement production has increased at a much higher speed than atmospheric CO{sub 2} concentration, i.e., than all major CO{sub 2} emission caused by human activities, such as energy and transportation. The authors are members of the European industrial research consortium GEOCISTEM, which is developing novel cements with very low CO{sub 2} emissions during their manufacture. The GEOCISTEM program started on January 1994. The authors are presenting the first results obtained so far. The technology presently developed for these novel cements (geopolymeric cements) is reducing the CO{sub 2} emission by 80%. Geopolymeric cements are manufactured in a different manner than Portland Cement. They do not rely on the calcination of calcium carbonate and therefore do not release bounded CO{sub 2}.

  2. Production of cements from Illinois coal ash. Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

    Wagner, J.C.; Bhatty, J.L.; Mishulovich, A.

    1997-05-01

    The objective of this program is to convert Illinois coal combustion residues, such as fly ash, bottom ash, and boiler slag, into novel cementitious materials for use in the construction industry. These residues are composed largely of SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, MgO, and CaO, which are also the major components of cement. Since the residues are used as an integral component of the cement and not just as additives to concrete, larger amounts of the residues can be utilized. The process uses submerged combustion to melt blends of coal combustion residues with lime, clay, and/or sand. The submerged combustion melter utilizes natural gas-oxidant firing directly into a molten bath to provide efficient melting of mineral-like materials. Use of this melter for cement production has many advantages over rotary kilns including very little, if any, grinding of the feed material, very low emissions, and compact size. During the first year of the program, samples of coal combustion residues were blended and mixed, as needed; with lime, clay, and/or sand to adjust the composition. Six mixtures, three with fly ash and three with bottom ash, were melted in a laboratory-scale furnace. The resultant products were used in mortar cubes and bars which were subjected to ASTM standard tests of cementitious properties. In the hydraulic activity test, mortar cubes were found to have a strength comparable to standard mortar cements. In the compressive strength test, mortar cubes were found to have strengths that exceeded ASTM blended cement performance specifications. In the ASR expansion test, mortar bars were subjected to alkali-silica reaction-induced expansion, which is a problem for siliceous aggregate-based concretes that are exposed to moisture. The mortar bars made with the products inhibited 85 to 97% of this expansion. These results show that residue-based products have an excellent potential as ASR-preventing additions in concretes.

  3. Nanotechnology Applications for Sustainable Cement-Based Products

    NASA Astrophysics Data System (ADS)

    Raki, L.; Beaudoin, J. J.; Alizadeh, R.

    Concrete is a macro-material strongly influenced by the properties of its components and hydrates at the nanoscale. Progress at this level will engender new opportunities for improvement of strength and durability of concrete materials. This article will focus on recent research work in the field of nanoscience applications to cement and concrete at the NRC-IRC. A particular attention will be given to nanoparticles and cement-based nanocomposites.

  4. Ultrasonic Characterization of the Curing Process of Polymethylmethacrylate-based Bone Cement Modified with Hydroxyapatite

    NASA Astrophysics Data System (ADS)

    Viano, Ann; Auwarter, Julie; Hoffmeister, Brent; Rho, Jae-Young

    2000-03-01

    The use of polymethylmethacrylate (PMMA)-based bone cement for implantation of metallic prostheses is becoming increasingly common. Failure of a cemented prosthesis often occurs when there is weak bonding at the bone/cement or cement/metal interface. The addition of hydroxyapatite (HA) particles, a synthetically produced version of the natural mineral in bone, may improve the adhesion by promoting bone growth into the cement itself. The curing time of PMMA bone cement determines the speed of implant insertion, which can affect the mechanical strength of the cement. Pure PMMA has a well-characterized curing time of 9-12 minutes, depending on environmental factors such as temperature and humidity. By measuring the propagation of ultrasonic pulses through a sample of bone cement, the curing process can be monitored. As the material hardens, the velocity of an ultrasonic pulse increases, and the attenuation decreases. These parameters were measured as a function of time for PMMA mixed with 0, 10 and 30investigation of the curing process as a function of hydroxyapatite concentration.

  5. Examination of the jarosite-alunite precipitate addition in the raw meal for the production of sulfoaluminate cement clinker.

    PubMed

    Katsioti, M; Tsakiridis, P E; Leonardou-Agatzini, S; Oustadakis, P

    2006-04-17

    The aim of the present research work was to investigate the possibility of adding a jarosite-alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low-grade nickel oxides ores, in the raw meal for the production of sulfoaluminate cement clinker. For that reason, two samples of raw meals were prepared, one contained 20% gypsum, as a reference sample ((SAC)Ref) and another with 11.31% jarosite-alunite precipitate ((SAC)J/A). Both raw meals were sintered at 1300 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite-alunite precipitate did not affect the mineralogical characteristics of the so produced sulfoaluminate cement clinker and there was confirmed the formation of the sulfoaluminate phase (C4A3S), the most typical phase of this cement type. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite-alunite precipitate did not negatively affect the quality of the produced cement. PMID:16223566

  6. Examination of the jarosite-alunite precipitate addition in the raw meal for the production of sulfoaluminate cement clinker.

    TOXLINE Toxicology Bibliographic Information

    Katsioti M; Tsakiridis PE; Leonardou-Agatzini S; Oustadakis P

    2006-04-17

    The aim of the present research work was to investigate the possibility of adding a jarosite-alunite chemical precipitate, a waste product of a new hydrometallurgical process developed to treat economically low-grade nickel oxides ores, in the raw meal for the production of sulfoaluminate cement clinker. For that reason, two samples of raw meals were prepared, one contained 20% gypsum, as a reference sample ((SAC)Ref) and another with 11.31% jarosite-alunite precipitate ((SAC)J/A). Both raw meals were sintered at 1300 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the jarosite-alunite precipitate did not affect the mineralogical characteristics of the so produced sulfoaluminate cement clinker and there was confirmed the formation of the sulfoaluminate phase (C4A3S), the most typical phase of this cement type. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of jarosite-alunite precipitate did not negatively affect the quality of the produced cement.

  7. In situ monitoring of the hydration process of K-PS geopolymer cement with ESEM

    SciTech Connect

    Sun Wei; Zhang Yunsheng; Lin Wei; Liu Zhiyong

    2004-06-01

    Environmental scanning electron microscope (ESEM) was used to in situ quantitatively study the hydration process of K-PS geopolymer cement under an 80% RH environment. An energy dispersion X-ray analysis (EDXA) was also employed to distinguish the chemical composition of hydration product. The ESEM micrographs showed that metakaolin particles pack loosely at 10 min after mixing, resulting in the existence of many large voids. As hydration proceeds, a lot of gels were seen and gradually precipitated on the surfaces of these particles. At later stage, these particles were wrapped by thick gel layers and their interspaces were almost completely filled. The corresponding EDXA results illustrated that the molar ratios of K/Al increase while Si/Al decrease with the development of hydration. As a result, the molar ratios of K/Al and Si/Al of hydration products at an age of 4 h amounted to 0.99 and 1.49, respectively, which were close to the theoretical values (K/Al=1.0, Si/Al=1.0 for K-PS geopolymer cement paste). In addition, well-developed crystals could not been found at any ages; instead, spongelike amorphous gels were always been observed.

  8. HAZARDOUS WASTE COMBUSTION IN INDUSTRIAL PROCESSES: CEMENT AND LIME KILNS

    EPA Science Inventory

    The report summarizes the results of several studies relating to hazardous waste combustion in cement and lime kilns. The tests included in the study are four kilns tested by the U.S. Environmental Protection Agency, four kilns tested by State agencies or the kiln operator, two C...

  9. Comparison of the fixation effects of heavy metals by cement rotary kiln co-processing and cement based solidification/stabilization.

    PubMed

    Zhang, Junli; Liu, Jianguo; Li, Cheng; Jin, Yiying; Nie, Yongfeng; Li, Jinhui

    2009-06-15

    Cement rotary kiln co-processing of hazardous wastes and cement based solidification/stabilization could both immobilize heavy metals. The different retention mechanisms of the two technologies lead to different fixation effects of heavy metals. The same amount of heavy metal compounds were treated by the two types of fixation technologies. Long-term leaching test (160 days), the maximum availability leaching test (NEN 7341) and a modified three-step sequential extraction procedure, proposed by the Commission of the European Communities Bureau of Reference (BCR) were employed to compare the fixation effects of the two fixation technologies. The leaching concentrations in NEN 7341 and long-term leaching tests were compared with identification standard for hazardous wastes (GB5085.3-1996) and drinking water standard (GB5749-2005). The results indicate that the leaching concentrations of the long-term leaching test and NEN 7341 test were lower than the regulatory limits and the leached ratios were small. Both cement based solidification/stabilization and cement rotary kiln co-processing could effectively fix heavy metals. Calcination in a cement rotary kiln and the following hydration that follows during cement application could fix As, Cd, Pb and Zn more effectively and decrease the release to the environment. Cement solidification/stabilization technology has better effect in immobilizing Cr and Ni. Cr wastes are more fitful to be treated by cement solidification/stabilization. PMID:19091467

  10. PIXE characterization of by-products resulting from the zinc recycling of industrial cemented carbides

    NASA Astrophysics Data System (ADS)

    Freemantle, C. S.; Sacks, N.; Topic, M.; Pineda-Vargas, C. A.

    2015-11-01

    By-product materials of the widely used zinc recycling process of cemented carbides have been studied. Scanning electron microscopy and micro-PIXE techniques have identified elemental concentrations, distributions and purity of by-product materials from an industrial zinc recycling plant. Cobalt surface enrichment, lamellar microstructures of varying composition, including alternating tungsten carbide (WC) grains and globular cobalt, and regions of excess zinc contamination were found in materials with incomplete zinc penetration. Liquid Co-Zn formation occurred above 72 wt.% Zn at the furnace temperature of 930 °C, and was extracted towards the surface of poorly zinc infiltrated material, primarily by the vacuum used for zinc distillation. Surface enrichment was not observed in material that was zinc infiltrated to the sample center, which was more friable and exhibited more homogeneous porosity and elemental concentrations. The result of incomplete zinc infiltration was an enriched surface zone of up to 60 wt.% Co, compared to an original sample composition of ∼10-15 wt.% Co. The impact on resulting powders could be higher or inhomogeneous cobalt content, as well as unacceptably high zinc concentrations. PIXE has proven it can be a powerful technique for solving industrial problems in the cemented carbide cutting tool industry, by identifying trace elements and their locations (such as Zn to 0.1 wt.% accuracy), as well as the distribution of major elements within WC-Co materials.

  11. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    NASA Astrophysics Data System (ADS)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  12. Minerals recovery from Salton Sea geothermal brines: a literature review and proposed cementation process

    SciTech Connect

    Maimoni, A.

    1982-01-01

    The potential for minerals recovery from a 1000-MWe combined geothermal power and minerals recovery plant in the Salton Sea is examined. While the possible value of minerals recovered would substantially exceed the revenue from power production, information is insufficient to carry out a detailed economic analysis. The recovery of precious metals - silver, gold and platinum - is the most important factor in determining the economics of a minerals recovery plant. However, the precious metal content of the brines is not certain. Such a power plant could recover 14 to 31% of the US demand for manganese and substantial amounts of zinc and lead. Previous work on minerals extraction from Salton Sea brines is reviewed and a new process, based on a fluidized-bed cementation reaction with metallic iron, is proposed. This process would recover the precious metals, lead and tin present in the brines.

  13. Effect of carbon dioxide injection on production of wood cement composites from waste medium density fiberboard (MDF).

    PubMed

    Qi, H; Cooper, P A; Wan, H

    2006-01-01

    The possibility of recycling waste medium density fiberboard (MDF) into wood-cement composites was evaluated. Both new fibers and recycled steam exploded MDF fibers had poor compatibility with cement if no treatment was applied, due to interference of the hydration process by the water soluble components of the fiber. However, this issue was resolved when a rapid hardening process with carbon dioxide injection was adopted. It appears that the rapid carbonation allowed the board to develop considerable strength before the adverse effects of the wood extractives could take effect. After 3-5 min of carbon dioxide injection, the composites reached 22-27% of total carbonation and developed 50-70% of their final (28-day) strength. Composites containing recycled MDF fibers had slightly lower splitting tensile strength and lower tensile toughness properties than those containing new fibers especially at a high fiber/cement ratio. Composites containing recycled MDF fibers also showed lower values of water absorption. Unlike composites cured conventionally, composites cured under CO(2) injection developed higher strength and toughness with increased fiber content. Incorporation of recycled MDF fibers into wood cement composites with CO(2) injection during the production stage presents a viable option for recycling of this difficult to manage waste material. PMID:16046114

  14. Cement and concrete

    NASA Technical Reports Server (NTRS)

    Corley, Gene; Haskin, Larry A.

    1992-01-01

    To produce lunar cement, high-temperature processing will be required. It may be possible to make calcium-rich silicate and aluminate for cement by solar heating of lunar pyroxene and feldspar, or chemical treatment may be required to enrich the calcium and aluminum in lunar soil. The effects of magnesium and ferrous iron present in the starting materials and products would need to be evaluated. So would the problems of grinding to produce cement, mixing, forming in vacuo and low gravity, and minimizing water loss.

  15. Sculpting with Cement.

    ERIC Educational Resources Information Center

    Olson, Lynn

    1983-01-01

    Cement offers many creative possibilities for school art programs. Instructions are given for sculpting with fiber-cement and sand-cement, as well as for finishing processes and the addition of color. Safety is stressed. (IS)

  16. Using the low-temperature plasma in cement production

    NASA Astrophysics Data System (ADS)

    Sazonova, N. A.; Skripnikova, N. K.

    2015-11-01

    The calculation of the raw-material mixtures and mineralogical composition of the cement clinkers which are synthezed on their base taking into account the disbalanced crystallization of the melting and glassing under conditions of the low-temperature plasma was performed. The difference of the actual values from the calculated ones is 0.69-3.73%. The composition which is characterized as the saturation coefficient 0,88; the silicate module - 3.34, the alumina module - 2.52 in melting of which the alite in amount 78.7%; 3CaOSiO2 - 4%; 3CaOAl2O3 - 9.8%; 12CaO7Al2O3 -2.9%; CaOfree - 1% formed using the lime-stone from the quarry Pereval in the town of Slyudyanka and the clay from the deposit Maximovski in Irkutsk Region is considered as the optimal one. The structure of the melted clinker is represented as the metastable minerals of alite in the lamellar form with the dimensions up to (3-20)(80-400) ?m and the ratio of length to width 26.6-133. The elongated crystal form may stipulate the high cement activity based on the melted clinkers, which is 82.7-84.2 MPa. Valid- ing the revealed high activity of the viscous substance was confirmed by the results of the scanning electronic microscopy, X-ray phase analysis, with using of which the quantitative and qualitative analyses of the clinker minerals having the deformed crystalic lattice; were performed the morphology of the minerals in the clinker and cement stone, received on its ground, was studied.

  17. Dolomite magnesium oxychloride cement properties control method during its production

    NASA Astrophysics Data System (ADS)

    Chernykh, T. N.; Nosov, A. V.; Kramar, L. Ya

    2015-01-01

    The work considers the possibility of reducing the decomposition temperature of MgCO3 in dolomite rock, provides the results of studies of the effect of various additives and enhancers on the decomposition of magnesium and calcium components of dolomite. Chlorides additives are the most promising for dolomite rocks roast intensification. They allow shifting the MgCO3 decomposition to lower temperatures, without exerting a significant influence on the decomposition of CaCO3. Introduction of additives-enhancers is found to be an effective method of controlling the properties of dolomite MOC during roasting, producing high-strength dolomite magnesium oxychloride cements with change in volume during solidification.

  18. Investigation of the energy-saving process of cement dispersion in a helium atmosphere

    NASA Astrophysics Data System (ADS)

    Klyavin, O. V.; Aruev, N. N.; Chernov, Yu. M.; Drinberg, A. S.; Fedorov, V. Yu.; Shpeizman, V. V.

    2014-06-01

    The process of commercial cement grinding in a helium atmosphere has been investigated in comparison with the process in an air atmosphere. Raw material particles have been sorted by sizes. Curves of helium release from the raw material after its grinding in air and in helium in the temperature range T = 20-1200C have been constructed and analyzed. The influence of the character of water molecule adsorption on raw material cement particles before and after grinding in air and in helium and on the shape of helium release curves has been revealed.

  19. Heuristic economic assessment of the Afghanistan construction materials sector: cement and dimension stone production

    USGS Publications Warehouse

    Mossotti, Victor G.

    2014-01-01

    Over the past decade, the U.S. Government has invested more than $106 billion for physical, societal, and governmental reconstruction assistance to Afghanistan (Special Inspector General for Afghanistan Reconstruction, 2012a). This funding, along with private investment, has stimulated a growing demand for particular industrial minerals and construction materials. In support of this effort, the U.S. Geological Survey released a preliminary mineral assessment in 2007 on selected Afghan nonfuel minerals (Peters and others, 2007). More recently, the 2007 mineral assessment was updated with the inclusion of a more extensive array of Afghan nonfuel minerals (Peters and others, 2011). As a follow-up on the 2011 assessment, this report provides an analysis of the current use and prospects of the following Afghan industrial minerals required to manufacture construction materials: clays of various types, bauxite, gypsum, cement-grade limestone, aggregate (sand and gravel), and dimension stone (sandstone, quartzite, granite, slate, limestone, travertine, marble). The intention of this paper is to assess the: Use of Afghan industrial minerals to manufacture construction materials, Prospects for growth in domestic construction materials production sectors, Factors controlling the competitiveness of domestic production relative to foreign imports of construction materials, and Feasibility of using natural gas as the prime source of thermal energy and for generating electrical energy for cement production. The discussion here is based on classical principles of supply and demand. Imbedded in these principles is an understanding that the attributes of supply and demand are highly variable. For construction materials, demand for a given product may depend on seasons of the year, location of construction sites, product delivery time, political factors, governmental regulations, cultural issues, price, and how essential a given product might be to the buyer. Moreover, failure on the supply side to mirror such attributes can be deal-breakers in a transaction. For qualitative interpretation of the findings in this report, the value chain was used to conceptualize the relation between supply and demand. Although quantitative data on the Afghan construction materials sector have been hard to come by, the premise herein was that qualitative aspects of supply and demand are revealed by following the flow of funding through projects of varying sizes. It was found that the spectrum of attributes on the demand side of large multimillion dollar reconstruction projects is generally high dimensional, distributed over a broad line of construction materials at diverse locations, and in varying quantities. As interpreted herein, project funds dispensed at the higher hierarchical levels of a project are often concentrated on procurement of construction materials and services at the upper end of the value chain. In contrast, project funds dispensed at the lower hierarchical levels are disseminated across a multiplicity of subprojects, thus restricting project acquisitions to the lower end of the value chain. Evidence suggests that under the current conditions in Afghanistan producers of construction materials at the lower end of the value chain (adobe brick, aggregate, low-end marble products) can successfully compete in local markets and turn a profit. In contrast, producers of energy-intensive products such as cement will continue to face intense competition from imports, at least in the near-term. In the long-term, as infrastructure issues are resolved, and as business conditions in Afghanistan improve, domestic producers will have a locational advantage in establishing a solid niche in their respective home markets. In the process of tendering properties for cement production, the pivotal issues of abundant, reliable, and cost-effective thermal and electrical energy sources for cement production have become prominent. Over the past 50 years, powdered coal and natural gas have been proven to be excellent fuels for firing kilns at cement plants, and both fuels are used as energy sources for electricity generation. After reviewing the main aspects of the coal and natural gas sectors, it is concluded here that the issues for plant design are not that of energy source feasibility but rather that of optimization of energy technologies for a given plant at a particular time and place, based on a diverse mix of energy and transport technologies.

  20. Effects of processing and materials variations on mechanical properties of lightweight cement composites

    SciTech Connect

    Park, S.B.; Yoon, E.S.; Lee, B.I.

    1999-02-01

    Low-density/low-cost cement composites were fabricated. Carbon and alkali-resistant glass fibers were used to reinforce the matrix of industrial by-products; fly ash with silica fume, Portland cement, and calcium silicates were mixed in different proportions. The additional low density was obtained by adding perlite and foaming agents followed by hot water curing. The composites also were prepared by autoclave curing for comparison. The mechanical properties were improved by increasing the amount of silica fume, fly ash, and fibers.Both carbon fibers and alkali-resistant glass fibers were effective in reinforcing the matrices, but carbon fibers were superior to glass fibers. Fabrication techniques for producing lightweight cement composites that can substitute for autoclaved lightweight concrete was developed.

  1. Technological features of cementation of liquid organic wastes from radiochemical production and NPP

    SciTech Connect

    Belyaeva, T.B.; Kiselev-Dmitriev, A.L.; Masanov, O.L.

    1993-12-31

    One method to manage liquid radioactive wastes is to incorporate them into inorganic materials. At VNINM, work was performed to cement spent oils and extractants and to determine final product properties. Attention was paid to a choice of emulsifiers. Parameters investigated included emulsifier availability, stability, and incorporability into a matrix material.

  2. Use of Ceramic Material (cement Clinker) for the Production of Biodiesel

    NASA Astrophysics Data System (ADS)

    Soni, Sunny; Agarwal, Madhu

    Biodiesel is a renewable liquid fuel made from natural, renewable biological sources such as edible and non edible oils. Over the last years, biodiesel has gained more market due to its benefits and because it appears as the natural substitute for diesel. Reasons for growing interest in biodiesel include its potential for reducing noxious emissions, potential contributions to rural economic development, as an additional demand center for agricultural commodities, and as a way to reduce reliance on foreign oil. Biodiesel was prepared from soybean oil by transesterification with methanol in the presence of cement clinker. Cement clinker was examined as a catalyst for a conversion of soybean oil to fatty acid methyl esters (FAMEs). It can be a promising heterogeneous catalyst for the production of biodiesel fuels from soybean oil because of high activity in the conversion and no leaching in the transesterification reaction. The reaction conditions were optimized. A study for optimizing the reaction parameters such as the reaction temperature, and reaction time, was carried out. The catalyst cement clinker composition was characterized by XRF. The results demonstrate that the cement clinker shows high catalytic performance & it was found that the yield of biodiesel can reach as high as 84.52% after 1 h reaction at 65C, with a 6:1 molar ratio of methanol to oil, 21 wt% KOH/cement clinker as catalyst.

  3. Pond ash -- A potential reactive raw material in the black meal process of cement manufacture by vertical shaft kiln (VSK) technology

    SciTech Connect

    Singh, N.B.; Bhattacharjee, K.N.; Shukla, A.K.

    1995-04-01

    Pond ash from thermal power plants serves as a reactive raw material in the black meal process of cement manufacture. Plant scale trials in a 50 TPD VSK plant have shown encouraging results in terms of quality improvement, energy conservation and enhanced production. Clinker produced was easy to grind resulting in saving of grinding energy.

  4. ENVIRONMENTAL CONSIDERATIONS OF SELECTED ENERGY CONSERVING MANUFACTURING PROCESS OPTIONS: VOLUME X. CEMENT INDUSTRY REPORT

    EPA Science Inventory

    This study assesses the likelihood of new process technology and new practices being introduced by energy intensive industries and explores the environmental impacts of such changes. Volume 10 deals with the cement industry and examines four options: (1) suspension preheater, (2)...

  5. Influence of mixture ratio and pH to solidification/stabilization process of hospital solid waste incineration ash in Portland cement.

    PubMed

    Sobiecka, Elzbieta; Obraniak, Andrzej; Antizar-Ladislao, Blanca

    2014-09-01

    Solidification/stabilization (S/S) is an established utilization technology to treat hazardous wastes. This research explored the influence of pH (3-12) on the immobilization of heavy metals present in five mixtures of hospital solid waste incinerator ash and Portland cement, following two different processes of waste solidification/stabilization (cement hydration and granulation). In general, cement hydration process resulted in more stable products than granulation process. A high ash content in the mixture with Portland cement (60wt%) resulted in the highest immobilization of Pb(2+) and Cu(2+), while a low ash content in the mixture (10wt%) resulted in the lowest leachability of Zn(2+). When ash and Portland cement was mixed in equal proportions (50wt%) the highest encapsulation was observed for Ni(2+), Cd(2+) and Cr(3+). Neutral and weak alkaline pH values within the range pH=7-8 resulted in the lowest leachability of the monitored heavy metals. PMID:24997895

  6. ELIMINATION OF WATER POLLUTION BY RECYCLING CEMENT PLANT KILN DUST

    EPA Science Inventory

    Excessive amounts of alkalies can have deleterious effects upon the process of cement manufacture and the product. Normally much of the alkali present in cement raw materials is volatilized in the cement kiln and condenses on the particles of kiln dust which are carried out of th...

  7. Formation of the Thermoelectric Candidate Chromium Silicide by Use of a Pack-Cementation Process

    NASA Astrophysics Data System (ADS)

    Stathokostopoulos, D.; Chaliampalias, D.; Tarani, E.; Theodorakakos, A.; Giannoulatou, V.; Polymeris, G. S.; Pavlidou, E.; Chrissafis, K.; Hatzikraniotis, E.; Paraskevopoulos, K. M.; Vourlias, G.

    2014-10-01

    Transition-metal silicides are reported to be good candidates for thermoelectric applications because of their thermal and structural stability, high electrical conductivity, and generation of thermoelectric power at elevated temperatures. Chromium disilicide (CrSi2) is a narrow-gap semiconductor and a potential p-type thermoelectric material up to 973 K with a band gap of 0.30 eV. In this work, CrSi2 was formed from Si wafers by use of a two-step, pack-cementation, chemical diffusion method. Several deposition conditions were used to investigate the effect of temperature and donor concentration on the structure of the final products. Scanning electron microscopy and x-ray diffraction analysis were performed for phase identification, and thermal stability was evaluated by means of thermogravimetric measurements. The results showed that after the first step, chromizing, the structure of the products was a mixture of several Cr-Si phases, depending on the donor (Cr) concentration during the deposition process. After the second step, siliconizing, the pure CrSi2 phase was formed as a result of Si enrichment of the initial Cr-Si phases. It was also revealed that this compound has thermoelectric properties similar to those reported elsewhere. Moreover, it was found to have exceptional chemical stability even at temperatures up to 1273 K.

  8. Clean burning process which converts pollutants into value added product

    SciTech Connect

    Zhu Xuefang

    1999-07-01

    By adding a multiple composite admixture in coal-fired boilers, the new technology turns ash and the sulfur in coal into cement clinker materials, deepens and stabilizes combustion process, decreases mechanical and chemical instabilities during combustion, and eliminates the production of NO{sub x}. While generating heat and power, the technology produces cement clinkers, and gets rid of the soot type of air pollution caused by cement kilns, thus effects a radical cure for the two pollution sources in coal-fired power plants and cement kilns. The new technology makes use of coal ashes as renewable resources, saves energy resources and the land needed to discard the ashes. Therefore, it benefits for ecological balance and economics.

  9. Recycling of the product of thermal inertization of cement-asbestos for various industrial applications

    SciTech Connect

    Gualtieri, Alessandro F.; Giacobbe, Carlotta; Sardisco, Lorenza; Saraceno, Michele; Lassinantti Gualtieri, Magdalena; Cavenati, Cinzia; Zanatto, Ivano

    2011-01-15

    Recycling of secondary raw materials is a priority of waste handling in the countries of the European community. A potentially important secondary raw material is the product of the thermal transformation of cement-asbestos, produced by prolonged annealing at 1200-1300 {sup o}C. The product is chemically comparable to a Mg-rich clinker. Previous work has assured the reliability of the transformation process. The current challenge is to find potential applications as secondary raw material. Recycling of thermally treated asbestos-containing material (named KRY.AS) in traditional ceramics has already been studied with successful results. The results presented here are the outcome of a long termed project started in 2005 and devoted to the recycling of this secondary raw materials in various industrial applications. KRY.AS can be added in medium-high percentages (10-40 wt%) to commercial mixtures for the production of clay bricks, rock-wool glasses for insulation as well as Ca-based frits and glass-ceramics for the production of ceramic tiles. The secondary raw material was also used for the synthesis of two ceramic pigments; a green uvarovite-based pigment [Ca{sub 3}Cr{sub 2}(SiO{sub 4}){sub 3}] and a pink malayaite-based pigment [Ca(Sn,Cr)SiO{sub 5}]. The latter is especially interesting as a substitute for cadmium-based pigments. This work also shows that KRY.AS can replace standard fillers in polypropylene plastics without altering the properties of the final product. For each application, a description and relevant results are presented and discussed.

  10. Recycling of the product of thermal inertization of cement-asbestos for various industrial applications.

    PubMed

    Gualtieri, Alessandro F; Giacobbe, Carlotta; Sardisco, Lorenza; Saraceno, Michele; Gualtieri, Magdalena Lassinantti; Lusvardi, Gigliola; Cavenati, Cinzia; Zanatto, Ivano

    2011-01-01

    Recycling of secondary raw materials is a priority of waste handling in the countries of the European community. A potentially important secondary raw material is the product of the thermal transformation of cement-asbestos, produced by prolonged annealing at 1200-1300 C. The product is chemically comparable to a Mg-rich clinker. Previous work has assured the reliability of the transformation process. The current challenge is to find potential applications as secondary raw material. Recycling of thermally treated asbestos-containing material (named KRYAS) in traditional ceramics has already been studied with successful results. The results presented here are the outcome of a long termed project started in 2005 and devoted to the recycling of this secondary raw materials in various industrial applications. KRYAS can be added in medium-high percentages (10-40 wt%) to commercial mixtures for the production of clay bricks, rock-wool glasses for insulation as well as Ca-based frits and glass-ceramics for the production of ceramic tiles. The secondary raw material was also used for the synthesis of two ceramic pigments; a green uvarovite-based pigment [Ca(3)Cr(2)(SiO(4))(3)] and a pink malayaite-based pigment [Ca(Sn,Cr)SiO(5)]. The latter is especially interesting as a substitute for cadmium-based pigments. This work also shows that KRYAS can replace standard fillers in polypropylene plastics without altering the properties of the final product. For each application, a description and relevant results are presented and discussed. PMID:20708915

  11. Capture of green-house carbon dioxide in Portland cement

    SciTech Connect

    Wagh, A.S.; Singh, D.; Pullockaran, J.; Knox, L.

    1993-12-31

    A novel process has been developed to sequester green-house carbon dioxide produced by the cement industry in precast cement products. Typically, 10--24 wt % of CO{sub 2} produced by calcination of calcium carbonate during clinkering of the cement may be captured. The carbonation process also cures the cement paste within minutes into hard bodies. The process maintains high pH conditions during curing, to allow conventional steel reinforcement of concrete. The process will save time and money to the cement industry, and at the same time, help them to comply with the Clean Air Act by sequestering the green-house carbon dioxide.

  12. The Impact of Thermocycling Process on the Dislodgement Force of Different Endodontic Cements

    PubMed Central

    Saghiri, Mohammad Ali; Asatourian, Armen; Garcia-Godoy, Franklin; Gutmann, James L.; Sheibani, Nader

    2013-01-01

    To evaluate the effects of thermocycling (500 cycles, 5C/55C) on the push-out bond strength of calcium silicate based cements including WMTA, Nano-WMTA, and Bioaggregate to root dentin. Forty-eight dentin slices were prepared and divided into 3 groups (n = 16) and filled with Angelus WMTA, Nano-WMTA, or Bioaggregate. After incubation, half of the samples were thermocycled while the other half remained untreated. Push-out bond strength was calculated, and the modes of the bond failures were determined by SEM. The highest bond strength was seen in nonthermocycled Nano-WMTA samples and the lowest in thermocycled Bioaggregate samples. The significant differences between nonthermocycled and thermocycled samples were only noticed in WMTA and Nano-WMTA groups (P < 0.001). The mode of failure for thermocycled samples of all three cements was mostly cohesive. Thermocycling process can drastically affect the push-out bond strength of calcium silicate based cements. The intrastructural damages occurred due to the thermal stresses, causing cohesive failures in set materials. Sealing property of endodontic cements which have experienced the thermal stresses can be jeopardized due to occlusal forces happening in furcation cites. PMID:24063004

  13. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Chemical engineering analyses involving the preliminary process design of a plant (1,000 metric tons/year capacity) to produce silicon via the technology under consideration were accomplished. Major activities in the chemical engineering analyses included base case conditions, reaction chemistry, process flowsheet, material balance, energy balance, property data, equipment design, major equipment list, production labor and forward for economic analysis. The process design package provided detailed data for raw materials, utilities, major process equipment and production labor requirements necessary for polysilicon production in each process.

  14. Silicon production process evaluations

    NASA Astrophysics Data System (ADS)

    1982-07-01

    Chemical engineering analyses involving the preliminary process design of a plant (1,000 metric tons/year capacity) to produce silicon via the technology under consideration were accomplished. Major activities in the chemical engineering analyses included base case conditions, reaction chemistry, process flowsheet, material balance, energy balance, property data, equipment design, major equipment list, production labor and forward for economic analysis. The process design package provided detailed data for raw materials, utilities, major process equipment and production labor requirements necessary for polysilicon production in each process.

  15. 75 FR 453 - FLSMidth, Inc., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Employment and Training Administration FLSMidth, Inc., Cement Division, Product Engineering, Including On-Site Leased Workers of Aerotek Contract Engineering, Allied Personnel Services, Eastern Engineering... Engineering, and Clarke Consulting, Inc., Bethlehem, PA; Amended Certification Regarding Eligibility To...

  16. Release of asbestos fibers from weathered and corroded asbestos cement products

    SciTech Connect

    Spurny, K.R.

    1989-02-01

    The controversy on whether weathered and corroded asbestos cement products are emitting biologically significant asbestos fiber concentrations in ambient air has not been resolved. Nor is it known if the weathered and corroded asbestos cement products release asbestos fibers which have the same carcinogenic potency as standard chrysotile. The purpose of this research project was to develop a method for sampling and measuring asbestos fiber emissions from solid planar surfaces (i.e., roofs and facades) consisting of asbestos cement products and to develop methods for studying the physical and chemical changes and the carcinogenic potency of the emitted fibers. Using this method asbestos fiber emissions in ambient air have been measured in the FRG during 1984/1986. The emissions of asbestos fibers longer than 5 microns were in the range 10(6) to 10(8) fibers/m2.hr. The ambient air concentrations of these asbestos fibers were for the most part less than 10(3) fibers/m3. It was shown that the emitted asbestos fibers were chemically changed and it was shown with animal experiments that their carcinogenic potency did not differ from the carcinogenicity of standard chrysotile fibers.

  17. Process, Product, and Playmaking

    ERIC Educational Resources Information Center

    Fisher, Maisha T.; Purcell, Susie Spear; May, Rachel

    2009-01-01

    This article examines relationships among process, product, and playmaking in a southeastern playwriting and performance program for teen girls, Playmaking for Girls (PFG). The authors have chosen to focus on tensions between process and product. Such tensions are present in the challenges teachers experience when privileging student-centered

  18. Calcination of kaolinite clay particles for cement production: A modeling study

    SciTech Connect

    Teklay, Abraham; Yin, Chungen; Rosendahl, Lasse; Bjer, Martin

    2014-07-01

    Kaolinite rich clay particles calcined under certain conditions can attain favorable pozzolanic properties and can be used to substitute part of the CO{sub 2} intensive clinker in cement production. To better guide calcination of a clay material, a transient one-dimensional single particle model is developed, which fully addresses the conversion process of raw kaolinite particles suspended in hot gas. Particles are discretized into a number of spherical cells, on each of which mass, momentum, energy and species conservation equations are numerically solved by using the finite volume method. Reactions considered in the model include dehydration, dehydroxylation and various phase transformations. Thermogravimetric analysis is used to determine reaction kinetic data required as inputs in the model and to validate the model. Finally, model-based sensitivity analysis is performed, from which quantitative guidelines for calcination condition optimization are derived. - Highlights: A general 1D mathematical model for single clay particle calcination is developed. The model fully addresses momentum, heat and mass transfer and all the reactions. Experiments are performed to determine kinetic data of the key reactions. The model is verified by different means, including experimental results. Sensitivity study is done to address key assumptions and derive useful guidelines.

  19. New magnesia-polyphosphate cement composites: Synthesis and processing under MDF-like conditions

    SciTech Connect

    Dimotakis, E.D.; Klemperer, W.G.; Young, J.F.

    1993-12-31

    Macro-Defect-Free (MDF) cements represent a major breakthrough in processing advanced cement-based materials. When a mixture of CaAl{sub 2}O{sub 4}/PVA (PVA = polyvinyl alcohol acetate) is processed under high shear mixing conditions, it transform into a high-strength material. The authors` current efforts have been focused on producing similar materials in a purely inorganic system. Thus MgO has been reacted at room temperature with sodium polyphosphates of the general formula Na{sub n}H{sub 2}P{sub n}O{sub 3n+1}{center_dot}xH{sub 2}O n = 6,15,70 and crystalline sodium Kurrol salts (NaPO{sub 3}){sub n}, n>1000, where n is the average degree of polymerization. Processing of all these sodium polyphosphates with MgO under MDF-like conditions gave cement pastes that had compressive strengths ranging from 130 MPa to 140 MPa at 10-12% porosties.

  20. Cement sealing

    SciTech Connect

    Cowan, K.M.

    1991-05-21

    This patent describes a process for cementing a selected part of a well. It comprises: determining a surfactant capable of reducing the volumetric shrinkage of an aqueous cement slurry from about 10% to about 75% during setting and hardening, ascertaining the amount of the surfactant necessary to accomplish the reduction in volumetric shrinkage, and injecting the slurry with the necessary amount of surfactant into the selected part of the well.

  1. Energy Efficient Microwave Hybrid Processing of Lime for Cement, Steel, and Glass Industries

    SciTech Connect

    Fall, Morgana L; Yakovlev, Vadim; Sahi, Catherine; Baranova, Inessa; Bowers, Johnney G; Esquenazi , Gibran L

    2012-02-10

    In this study, the microwave materials interactions were studied through dielectric property measurements, process modeling, and lab scale microwave hybrid calcination tests. Characterization and analysis were performed to evaluate material reactions and energy usage. Processing parameters for laboratory scale and larger scale calcining experiments were developed for MAT limestone calcination. Early stage equipment design concepts were developed, with a focus on microwave post heating treatment. The retrofitting of existing rotary calcine equipment in the lime industry was assessed and found to be feasible. Ceralink sought to address some of the major barriers to the uptake of MAT identified as the need for (1) team approach with end users, technology partners, and equipment manufacturers, (2) modeling that incorporates kiln materials and variations to the design of industrial microwave equipment. This project has furthered the commercialization effort of MAT by working closely with an industrial lime manufacturer to educate them regarding MAT, identifying equipment manufacturer to supply microwave equipment, and developing a sophisticated MAT modeling with WPI, the university partner. MAT was shown to enhance calcining through lower energy consumption and faster reaction rates compared to conventional processing. Laboratory testing concluded that a 23% reduction in energy was possible for calcining small batches (5kg). Scale-up testing indicated that the energy savings increased as a function of load size and 36% energy savings was demonstrated (22 kg). A sophisticated model was developed which combines simultaneous microwave and conventional heating. Continued development of this modeling software could be used for larger scale calcining simulations, which would be a beneficial low-cost tool for exploring equipment design prior to actual building. Based on these findings, estimates for production scale MAT calcining benefits were calculated, assuming uptake of MAT in the US lime industry. This estimate showed that 7.3 TBTU/year could be saved, with reduction of 270 MMlbs of CO2 emissions, and $29 MM/year in economic savings. Taking into account estimates for MAT implementation in the US cement industry, an additional 39 TBTU/year, 3 Blbs of CO2 and $155 MM/year could be saved. One of the main remaining barriers to commercialization of MAT for the lime and cement industries is the sheer size of production. Through this project, it was realized that a production size MAT rotary calciner was not feasible, and a different approach was adapted. The concept of a microwave post heat section located in the upper portion of the cooler was devised and appears to be a more realistic approach for MAT implementation. Commercialization of this technology will require (1) continued pilot scale calcining demonstrations, (2) involvement of lime kiln companies, and (3) involvement of an industrial microwave equipment provider. An initial design concept for a MAT post-heat treatment section was conceived as a retrofit into the cooler sections of existing lime rotary calciners with a 1.4 year payback. Retrofitting will help spur implementation of this technology, as the capital investment will be minimal for enhancing the efficiency of current rotary lime kilns. Retrofits would likely be attractive to lime manufacturers, as the purchase of a new lime kiln is on the order of a $30 million dollar investment, where as a MAT retrofit is estimated on the order of $1 million. The path for commercialization lies in partnering with existing lime kiln companies, who will be able to implement the microwave post heat sections in existing and new build kilns. A microwave equipment provider has been identified, who would make up part of the continued development and commercialization team.

  2. Recycling the product of thermal transformation of cement-asbestos for the preparation of calcium sulfoaluminate clinker.

    PubMed

    Viani, Alberto; Gualtieri, Alessandro F

    2013-09-15

    According to recent resolutions of the European Parliament (2012/2065(INI)), the need for environmentally friendly alternative solutions to landfill disposal of hazardous wastes, such as asbestos-containing materials, prompts their recycling as secondary raw materials (end of waste concept). In this respect, for the first time, we report the recycling of the high temperature product of cement-asbestos, in the formulation of calcium sulfoaluminate cement clinkers (novel cementitious binders designed to reduce CO? emissions), as a continuation of a previous work on their systematic characterization. Up to 29 wt% of the secondary raw material was successfully introduced into the raw mix. Different clinker samples were obtained at 1250 C and 1300 C, reproducing the phase composition of industrial analogues. As an alternative source of Ca and Si, this secondary raw material allows for a reduction of the CO? emissions in cement production, mitigating the ecological impact of cement manufacturing, and reducing the need for natural resources. PMID:23856311

  3. Fan System Optimization Improves Production and Saves Energy at Ash Grove Cement Plant

    SciTech Connect

    Not Available

    2002-05-01

    This case study describes an optimization project implemented on a fan system at Ash Grove Cement Company, which led to annual energy and maintenance savings of $16,000 and 175,000 kilowatt-hours (kWh). In 1999, Ash Grove Cement Company implemented an optimization project on a fan system in its cement plant in Durkee, Oregon. Because of a severe vibration problem, the fan system would often fail and require frequent repairs to the ductwork and adjoining machinery. The plant replaced the belt drive with an Adjustable Speed Drive (ASD) to improve the control of the fan system and lower its energy consumption. This change eliminated the vibration problem and improved the system's airflow control and energy efficiency. The project led to annual energy and maintenance savings of $16,000 and 175,000 kilowatt-hours (kWh). In addition, the fan system's improved reliability allowed the plant to achieve its desired production level. Because of partial funding from the Northwest Energy Efficiency Alliance (NEEA), the total project cost was approximately $10,000, which gave the Durkee plant a simple payback of 7.5 months.

  4. Modeling of a self-healing process in blast furnace slag cement exposed to accelerated carbonation

    NASA Astrophysics Data System (ADS)

    Zemskov, Serguey V.; Ahmad, Bilal; Copuroglu, Oguzhan; Vermolen, Fred J.

    2013-02-01

    In the current research, a mathematical model for the post-damage improvement of the carbonated blast furnace slag cement (BFSC) exposed to accelerated carbonation is constructed. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate, which is incorporated into the impregnation of the sodium mono-fluorophosphate (Na-MFP) solution. The model of the self-healing process is built under the assumption that the position of the carbonation front changes in time where the rate of diffusion of Na-MFP into the carbonated cement matrix and the reaction rates of the free phosphate and fluorophosphate with the components of the cement are comparable to the speed of the carbonation front under accelerated carbonation conditions. The model is based on an initial-boundary value problem for a system of partial differential equations which is solved using a Galerkin finite element method. The results obtained are discussed and generalized to a three-dimensional case.

  5. Reduced carbon emission estimates from fossil fuel combustion and cement production in China.

    PubMed

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A; Feng, Kuishuang; Peters, Glen P; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-20

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon). PMID:26289204

  6. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    NASA Astrophysics Data System (ADS)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J.; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J.; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A.; Feng, Kuishuang; Peters, Glen P.; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-01

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = +/-7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  7. Fjords: Processes and products

    SciTech Connect

    Syvitski, J.P.M.; Burrell, D.C.; Skei, J.M.

    1987-01-01

    Fjords are a major feature of coasts and provide geologists and oceanographers with an excellent environment for studying and modeling coastal processes and products. This book brings together and integrates an enormous amount of information on fjords and provides the reader with a thorough, interdisciplinary account of current research with emphasis on sedimentary processes. The processes demonstrated in fjords are often relevant to the estuarine or open ocean environment.

  8. Phase development in the hardening process of two calcium phosphate bone cements: an energy dispersive X-ray diffraction study

    SciTech Connect

    Generosi, A.; Smirnov, V.V.; Rau, J.V.; Albertini, V. Rossi; Ferro, D.; Barinov, S.M.

    2008-03-04

    This work was aimed at the application of an energy dispersive X-ray diffraction technique to study the kinetics of phase development during the setting and hardening reactions in two calcium phosphate bone cements. The cements under study are based on either tricalcium phosphate or tetracalcium phosphate initial solid phase, and a magnesium carbonate-phosphoric acid liquid phase as the hardening liquid. The application of the energy dispersive X-ray diffraction method allowed to collect the diffraction patterns from the cement pastes in situ starting from 1 min of the setting and hardening process. The only crystallized phase in both cements was apatite-like phase, the primary crystallization process proceeds during a few seconds of the setting reaction. Both the compressive strength and the pH value changes during the hardening period can be attributed to the transformations occurring in the intergranular X-ray amorphous phase.

  9. ALARA Design Review for the Resumption of the Plutonium Finishing Plant (PFP) Cementation Process Project Activities

    SciTech Connect

    DAYLEY, L.

    2000-06-14

    The requirements for the performance of radiological design reviews are codified in 10CFR835, Occupational Radiation Protection. The basic requirements for the performance of ALARA design reviews are presented in the Hanford Site Radiological Control Manual (HSRCM). The HSRCM has established trigger levels requiring radiological reviews of non-routine or complex work activities. These requirements are implemented in site procedures HNF-PRO-1622 and 1623. HNF-PRO-1622 Radiological Design Review Process requires that ''radiological design reviews [be performed] of new facilities and equipment and modifications of existing facilities and equipment''. In addition, HNF-PRO-1623 Radiological Work Planning Process requires a formal ALARA Review for planned activities that are estimated to exceed 1 person-rem total Dose Equivalent (DE). The purpose of this review is to validate that the original design for the PFP Cementation Process ensures that the principles of ALARA (As Low As Reasonably Achievable) were included in the original project design. That is, that the design and operation of existing Cementation Process equipment and processes allows for the minimization of personnel exposure in its operation, maintenance and decommissioning and that the generation of radioactive waste is kept to a minimum.

  10. The hydration products of Portland cement in the presence of tin(II) chloride

    SciTech Connect

    Hill, J.; Sharp, J.H

    2003-01-01

    The hydration products of Portland cement pastes cured using water containing tin(II) chloride have been compared with those using distilled water. In the latter case, the expected products - portlandite, ettringite and calcite - were observed. The X-ray diffraction patterns of the cement pastes cured in the presence of tin(II) chloride showed several additional peaks that have been attributed to the formation of calcium hydroxo-stannate, CaSn(OH){sub 6}, and Friedel's salt (tetracalcium aluminate dichloride-10-hydrate), Ca{sub 3}Al{sub 2}O{sub 6}{center_dot}CaCl{sub 2}{center_dot}10H{sub 2}O. The amount of portlandite formed was reduced in the presence of tin(II) chloride. Calcium hydroxo-stannate contains tin in the +IV oxidation state and equations are presented to account for the oxidation of Sn(II) to Sn(IV) preceding the formation of CaSn(OH){sub 6} and Friedel's salt.

  11. Borehole cementing over water

    SciTech Connect

    Perkins, T.K.

    1984-05-01

    A borehole cementing process is disclosed in which a quantity of water-like fluid is pumped into a borehole above drilling mud and the cement slurry is pumped into the borehole above at least a portion of the water-like fluid. Turbulent mixing of cement slurry and water at the interface creates an isolation zone preventing degradation of the bulk of the cement slug.

  12. Hazardous-waste combustion in industrial processes: cement and lime kilns

    SciTech Connect

    Mournighan, R.E.; Branscome, M.

    1987-11-01

    This report summarizes the results of several studies relating to hazardous-waste combustion in cement and lime kilns. The tests included in the study are four kilns tested by the U.S. Environmental Protection Agency, four kilns tested by State agencies or the kiln operator, two Canadian tests, and one Swedish test. The predominant types of wastes tested included chlorinated organic compounds, aromatic compounds, and metal-contaminated waste oil. The kiln types include lime kilns and cement kilns, which included the dry, wet, and preheated processes. Fabric filters and electrostatic precipitators (ESPs) were the pollution-control devices used in these processes, and the primary fuels included coal, coke, coal/coke, fuel oil, and natural gas/coke. The parameters examined in the report were Destruction and Removal Efficiency (DRE) of the Principal Organic Hazardous Constitutents, particulate and HCl emissions, metals, and the effect of burning hazardous waste on SO/sub 2/, NOx, and CO emissions. The primary conclusion of the study is that DRE's of 99.99% or greater can be obtained in properly-operated calcining kilns. Particulate matter can increase when chlorinated wastes are burned in a kiln equipped with an electrostatic precipitator. Those kilns equipped with fabric filters showed no change in emissions.

  13. Cement As a Waste Form for Nuclear Fission Products: The Case of (90)Sr and Its Daughters.

    PubMed

    Dezerald, Lucile; Kohanoff, Jorge J; Correa, Alfredo A; Caro, Alfredo; Pellenq, Roland J-M; Ulm, Franz J; Saúl, Andrés

    2015-11-17

    One of the main challenges faced by the nuclear industry is the long-term confinement of nuclear waste. Because it is inexpensive and easy to manufacture, cement is the material of choice to store large volumes of radioactive materials, in particular the low-level medium-lived fission products. It is therefore of utmost importance to assess the chemical and structural stability of cement containing radioactive species. Here, we use ab initio calculations based on density functional theory (DFT) to study the effects of (90)Sr insertion and decay in C-S-H (calcium-silicate-hydrate) in order to test the ability of cement to trap and hold this radioactive fission product and to investigate the consequences of its β-decay on the cement paste structure. We show that (90)Sr is stable when it substitutes the Ca(2+) ions in C-S-H, and so is its daughter nucleus (90)Y after β-decay. Interestingly, (90)Zr, daughter of (90)Y and final product in the decay sequence, is found to be unstable compared to the bulk phase of the element at zero K but stable when compared to the solvated ion in water. Therefore, cement appears as a suitable waste form for (90)Sr storage. PMID:26513644

  14. Microstructural and bulk property changes in hardened cement paste during the first drying process

    SciTech Connect

    Maruyama, Ippei; Nishioka, Yukiko; Igarashi, Go; Matsui, Kunio

    2014-04-01

    This paper reports the microstructural changes and resultant bulk physical property changes in hardened cement paste (hcp) during the first desorption process. The microstructural changes and solid-phase changes were evaluated by water vapor sorption, nitrogen sorption, ultrasonic velocity, and {sup 29}Si and {sup 27}Al nuclear magnetic resonance. Strength, Young's modulus, and drying shrinkage were also examined. The first drying process increased the volume of macropores and decreased the volume of mesopores and interlayer spaces. Furthermore, in the first drying process globule clusters were interconnected. During the first desorption, the strength increased for samples cured at 100% to 90% RH, decreased for 90% to 40% RH, and increased again for 40% to 11% RH. This behavior is explained by both microstructural changes in hcp and CSH globule densification. The drying shrinkage strains during rapid drying and slow drying were compared and the effects of the microstructural changes and evaporation were separated.

  15. Production of a calcium silicate cement material from alginate impression material.

    PubMed

    Washizawa, Norimasa; Narusawa, Hideaki; Tamaki, Yukimichi; Miyazaki, Takashi

    2012-01-01

    The purpose of this study was to synthesize biomaterials from daily dental waste. Since alginate impression material contains silica and calcium salts, we aimed to synthesize calcium silicate cement from alginate impression material. Gypsum-based investment material was also investigated as control. X-ray diffraction analyses revealed that although firing the set gypsum-based and modified investment materials at 1,200°C produced calcium silicates, firing the set alginate impression material did not. However, we succeeded when firing the set blend of pre-fired set alginate impression material and gypsum at 1,200°C. SEM observations of the powder revealed that the featured porous structures of diatomite as an alginate impression material component appeared useful for synthesizing calcium silicates. Experimentally fabricated calcium silicate powder was successfully mixed with phosphoric acid solution and set by depositing the brushite. Therefore, we conclude that the production of calcium silicate cement material is possible from waste alginate impression material. PMID:22864217

  16. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Engineering design of the third distillation column in the process was accomplished. The initial design is based on a 94.35% recovery of dichlorosilane in the distillate and a 99.9% recovery of trichlorosilane in the bottoms. The specified separation is achieved at a reflux ratio of 15 with 20 trays (equilibrium stages). Additional specifications and results are reported including equipment size, temperatures and pressure. Specific raw material requirements necessary to produce the silicon in the process are presented. The primary raw materials include metallurgical grade silicon, silicon tetrachloride, hydrogen, copper (catalyst) and lime (waste treatment). Hydrogen chloride is produced as by product in the silicon deposition. Cost analysis of the process was initiated during this reporting period.

  17. Environmental assessment of sewage sludge as secondary raw material in cement production--a case study in China.

    PubMed

    Hong, Jinglan; Li, Xiangzhi

    2011-06-01

    A life cycle assessment was carried out to estimate the environmental impact of sewage sludge as secondary raw material in cement production. To confirm and add credibility to the study, uncertainty analysis was conducted. Results showed the impact generated from respiratory inorganics, terrestrial ecotoxicity, global warming, and non-renewable energy categories had an important contribution to overall environmental impact, due to energy, clinker, and limestone production stages. Also, uncertainty analysis results showed the technology of sewage sludge as secondary raw material in cement production had little or no effect on changing the overall environmental potential impact generated from general cement production. Accordingly, using the technology of sewage sludge as secondary raw material in cement production is a good choice for reducing the pressure on the environment from dramatically increased sludge disposal. In addition, increasing electricity recovery rate, choosing natural gas fired electricity generation technology, and optimizing the raw material consumption in clinker production are highly recommended to reduce the adverse effects on the environment. PMID:21288709

  18. Cement plant CKD recovery system

    SciTech Connect

    Cohen, S.M.; Prokesch, M.E.

    1996-12-31

    A fluid bed system has been developed to produce a low alkali cement clinker from cement plant kiln ducts (CKD). The system is comprised of three main components: feed preparation system, fluid bed reactor and process gas handling system. Cement kiln dust is first pelletized and dried, then processed at 1,300--1,320 C in the fluid bed reactor. The combination of excellent thermal transfer and extended retention time at reaction temperatures provides typical volatilization rates on the order of 90% K{sub 2}O, 70% Na{sub 2}O, 90% SO{sub 3}, and 95% Cl. High concentrations of volatilized alkali compounds in the process off gas stream are cooled and condensed in a specially designed heat exchange system while providing preheated process air for the fluid bed reactor. Condensed alkali compounds are collected at the dust collector in the form of a fine, white powder. This co-product may offer marketable value due to its high concentration of potassium sulfates. The system offers the potential for a 100% recovery of cement kiln dusts to produce cement clinker and an alkali co-product.

  19. Principles of squeeze cementing

    SciTech Connect

    Goodwin, K.J.

    1984-03-01

    Squeeze cementing is, by historical definition, the application of differential pressure across a cement slurry to accomplish the process of cement dehydration. The primary purpose of the dehydration is to create immobility of the cement slurry until some compressive strength can be developed. Current cementing technology and additives have improved the process sufficiently that the term ''squeeze'' may no longer be applicable. It is felt that ''Remedial Cement Placement'' may be more appropriate, and may more accurately define the process. The success of a remedial cementing operation depends on a finite definition of the existing problem and the results expected from the operation. If the purpose of the squeeze is not definable, a squeeze job may not be necessary. Significant completion dollars are wasted annually on unnecessary squeezes, poorly designed squeeze slurries, and/or improper slurry placement.

  20. The transformation sequence of cement-asbestos slates up to 1200 degrees C and safe recycling of the reaction product in stoneware tile mixtures.

    PubMed

    Gualtieri, A F; Cavenati, C; Zanatto, I; Meloni, M; Elmi, G; Gualtieri, M Lassinantti

    2008-04-01

    Cement-asbestos is the main asbestos containing material still found in most of the European countries such as Italy. Man- and weathering-induced degradation of the cement-asbestos slates makes them a source of dispersion of asbestos fibres and represents a priority cause of concern. This concern is the main prompt for the actual policy of abatement and disposal of asbestos containing materials in controlled wastes. An alternative solution to the disposal in dumping sites is the direct temperature-induced transformation of the cement-asbestos slates into non-hazardous mineral phases. This patented process avoids the stage of mechanical milling of the material before the treatment, which improves the reactivity of the materials but may be critical for the dispersion of asbestos fibres in working and life environment. For the first time, this paper reports the description of the reaction path taking place during the firing of cement-asbestos slates up to the complete transformation temperature, 1200 degrees C. The reaction sequence was investigated using different experimental techniques such as optical and electron microscopy, in situ and ex situ quali-quantitative X-ray powder diffraction. The understanding of the complex reaction path is of basic importance for the optimization of industrial heating processes leading to a safe recycling of the transformed product. For the recycling of asbestos containing materials, the Italian laws require that the product of the crystal chemical transformation of asbestos containing materials must be entirely asbestos-free, and should not contain more than 0.1 wt% fraction of the carcinogenic substances such as cristobalite. Moreover, if fibrous phases other than asbestos (with length to diameter ratio >3) are found, they must have a geometrical diameter larger than 3 microm. We have demonstrated that using an interplay of different experimental techniques, it is possible to safely verify the complete transformation of asbestos minerals in this temperature-induced process. The product of transformation of cement-asbestos (CATP) has a phase composition similar to that of a natural or a low temperature clinker with the exception of having a larger content of aluminium, iron and magnesium. This product can be safely recycled for the production of stoneware tile mixtures. The addition of 3-5 mass% of CATP does not bear significant variations to the standard parameters of white porcelain tile mixtures. PMID:17709183

  1. Utilization of lime-sinter process residue for the manufacture of a low-alumina portland cement

    SciTech Connect

    Chesley, J.A.; Murtha, M.J.; Burnet, G.

    1984-01-01

    The lime-sinter process for recovery of alumina from coal conversion solid wastes produces a residue that is largely dicalcium silicate (C/sub 2/S) and that contains only 3 to 5% Al/sub 2/O/sub 3/. Use of this residue will eliminate the need for its disposal and will make the lime-sinter process more attractive financially. The unique composition of the residue makes it an attractive raw material for the manufacture of ASTM Type V (sulfate resistant) portland cement. There is a substantial demand for this type of cement in the western states. The feasibility of thus using the residue is examined and a cost analysis for a combined alumina-portland cement plant capable of using the fly ash from a 1000 MWe coal-fired power station is presented. 12 references, 1 figure, 6 tables.

  2. Butadiene production process overview.

    PubMed

    White, Wm Claude

    2007-03-20

    Over 95% of butadiene is produced as a by-product of ethylene production from steam crackers. The crude C4 stream isolated from the steam cracking process is fed to butadiene extraction units, where butadiene is separated from the other C4s by extractive distillation. The amount of crude C4s produced in steam cracking is dependent on the composition of the feed to the cracking unit. Heavier feeds, such as naphtha, yield higher amounts of C4s and butadiene than do lighter feeds. Crackers using light feeds typically produce low quantities of C4s and do not have butadiene extraction units. Overall butadiene capacity is determined by ethylene cracker operating rates, the type of feed being cracked, and availability of butadiene extraction capacity. Global butadiene capacity is approximately 10.5 million metric tons, and global production is approximately 9 million metric tons [Chemical Marketing Associates, Inc. (CMAI), 2005 World Butadiene Analysis, Chemical Marketing Associates, Inc. (CMAI), 2005]. Crude C4s are traded globally, with the United States being the only significant net importer. Finished butadiene is also traded globally, with the largest exporters being Canada, Western Europe, Saudi Arabia and Korea. The largest net importers are Mexico, the United States and China. The global demand for butadiene is approximately 9 million metric tons [Chemical Marketing Associates, Inc. (CMAI), 2005 World Butadiene Analysis, Chemical Marketing Associates, Inc. (CMAI), 2005]. Production of styrene-butadiene rubber and polybutadiene rubber accounts for about 54% of global butadiene demand, with tire production being the single most important end use of butadiene synthetic rubbers. Other major butadiene derivatives are acrylonitrile-butadiene-styrene (ABS) and styrene butadiene latex (about 24% of demand combined). PMID:17324391

  3. Effects of test sample shape and surface production method on the fatigue behaviour of PMMA bone cement.

    PubMed

    Sheafi, E M; Tanner, K E

    2014-01-01

    There is no consensus over the optimal criterion to define the fatigue life of bone cement in vitro. Fatigue testing samples have been made into various shapes using different surface preparation techniques with little attention being paid to the importance of these variations on the fatigue results. The present study focuses on the effect of test sample shape and surface production method on the fatigue results. The samples were manufactured with two cross sectional shapes: rectangular according to ISO 527 and circular according to ASTM F2118. Each shape was produced using two methods: direct moulding of the cement dough and machining from oversized rods. Testing was performed using two different bone cements: SmartSet GHV and DePuy CMW1. At least 10 samples of each category were tested, under fully reversed tension-compression fatigue stress at ±20MPa, to allow for Weibull analysis to compare results. The growth of fatigue cracks was observed by means of the changes in the absorbed energy and apparent modulus. It was found that fatigue crack growth can be altered by the sample shape and production method; however it is also dependent on the chemical composition of the cement. The results revealed that moulded samples, particularly those based on the ASTM F2118 standard, can lead to up to 5.5 times greater fatigue lives compared to the machined samples of the same cement. It is thus essential, when comparing the fatigue results of bone cement, to consider the effect of production method along with the shape of the test sample. PMID:24070780

  4. Hierarchical Model Predictive Control Applied to a Cement Raw Material Mixing Process

    NASA Astrophysics Data System (ADS)

    Iino, Yutaka; Abe, Koichi; Tsukamoto, Yasuhisa

    A practical model predictive control method is proposed which was applied to a cement raw material mixing process. The method has a hierarchical structure of 3 layers consisted of set point calculation with an optimizer, multi-input multi-output material mixing ratio control system with the Model Predictive Control scheme, and local control system DCS (Distributed Control System) with PID controllers. It realized priority management of multi-objective control specifications and constraints, avoidance of infeasibility in optimization, handling of control degree of freedom, feed-forward control for transient manipulation, and adaptation to the time-varying components in each raw material with Kalman filtering estimator. A 72-hour test operation was executed for a real plant with regular raw materials and some additive industrial waste materials, which revealed good control performance and reached an economical optimal operation point automatically.

  5. Middle Pleistocene carbonate-cemented colluvium in southern Poland: Its depositional processes, diagenesis and regional palaeoenvironmental significance

    NASA Astrophysics Data System (ADS)

    Gradzi?ski, Micha?; Hercman, Helena; Staniszewski, Krzysztof

    2014-06-01

    A colluvial origin is postulated for the enigmatic relic mantle of immature, carbonate-cemented rudites on the bedrock slope of Krakw Highland, preserved in the area of Kwacza?a Gullies. The deposits comprise four sedimentary facies: (A) sporadic clast-supported openwork conglomerates; (B) predominant matrix-supported massive conglomerates, some with a coarse-tail normal grading; (C) subordinate sheets of parallel stratified and/or ripple cross-laminated fine-grained sandstones; and (D) local coarse-grained sandstones with gently inclined parallel stratification. The 230Th-U dating of sparry calcite cements points to the penultimate Odranian/Warthanian interglacial. The debris was derived from local bedrock, inferred to have been frost-shattered in permafrost conditions during the Odranian glacial. Colluvial resedimentation was triggered by the rapid change in environment conditions brought by early deglaciation. Dense-snow/slush flows and slush-laden watery debris flows are thought to have transferred limestone debris from the upper to middle hillslope, where siliciclastic sand matrix was incorporated and solifluctional creep prevailed, accompanied by slope sheetwash processes. Carbonate cementation of the talus occurred in phreatic conditions during the penultimate Odranian/Warthanian interglacial (marine isotope stage 7), when soils formed and local springs supplied carbonate-saturated groundwater. The patchy preservation of cemented colluvium indicates its erosional relics. The Pleistocene colluvial mantle in the Krakw Highland was probably extensive, but was removed by subsequent erosion where non-cemented.

  6. Assessment of ferrous chloride and Portland cement for the remediation of chromite ore processing residue.

    PubMed

    Jagupilla, Santhi C; Wazne, Mahmoud; Moon, Deok Hyun

    2015-10-01

    Chromite Ore Processing Residue (COPR) is an industrial waste containing up to 7% chromium (Cr) including up to 5% hexavalent chromium [Cr(VI)]. The remediation of COPR has been challenging due to the slow release of Cr(VI) from a clinker like material and thereby the incomplete detoxification of Cr(VI) by chemical reagents. The use of sulfur based reagents such as ferrous sulfate and calcium polysulfide to detoxify Cr(VI) has exasperated the swell potential of COPR upon treatment. This study investigated the use of ferrous chloride alone and in combination with Portland cement to address the detoxification of Cr(VI) in COPR and the potential swell of COPR. Chromium regulatory tests, X-ray powder diffraction (XRPD) analyses and X-ray absorption near edge structure (XANES) analyses were used to assess the treatment results. The treatment results indicated that Cr(VI) concentrations for the acid pretreated micronized COPR as measured by XANES analyses were below the New Jersey Department of Environmental Protection (NJDEP) standard of 20 mg kg(-1). The Toxicity characteristic leaching procedure (TCLP) Cr concentrations for all acid pretreated samples also were reduced below the TCLP regulatory limit of 5 mg L(-1). Moreover, the TCLP Cr concentration for the acid pretreated COPR with particle size ⩽0.010 mm were less than the universal treatment standard (UTS) of 0.6 mg L(-1). The treatment appears to have destabilized all COPR potential swell causing minerals. The unconfined compressive strength (UCS) for the treated samples increased significantly upon treatment with Portland cement. PMID:25966327

  7. Reuse of grits waste for the production of soil--cement bricks.

    PubMed

    Siqueira, F B; Holanda, J N F

    2013-12-15

    This investigation focuses on the reuse of grits waste as a raw material for replacing Portland cement by up to 30wt.% in soil-cement bricks. The grits waste was obtained from a cellulose factory located in south-eastern Brazil. We initially characterized the waste sample with respect to its chemical composition, X-ray diffraction, fineness index, morphology, pozzolanic activity, and pollution potential. Soil-cement bricks were then prepared using the waste material and were tested to determine their technological properties (e.g., water absorption, apparent density, volumetric shrinkage, and compressive strength). Microstructural evolution was accompanied by confocal microscopy. It was found that the grits waste is mainly composed of calcite (CaCO3) particles. Our results indicate that grits waste can be used economically, safely, and sustainably at weight percentages of up to 20% to partially replace Portland cement in soil-cement bricks. PMID:24140481

  8. Performance of lime-soda sinter process residue in the manufacture of sulfate-resistant portland cement

    SciTech Connect

    Chesley, J.A.; Burnet, G.

    1986-04-25

    The residue from the Ames Lime-Soda Sinter Process for recovering alumina from power plant fly ash consists largely of dicalcium silicate and shows promise as a raw material for the manufacture of a low-alumina, sulfate-resistant portland cement. A laboratory burnability study has been conducted to determine the best way to utilize this raw material from both clinker quality and economic perspectives. These tests are essential when a new material, such as the lime-sinter process residue, it to be considered as a possible cement raw material. The amount of unreacted lime can be used as a measure of the reactivity of a raw mix by indicating the extent to which the cement reactions have progressed. Conditions of residence time and temperature used for the burnability tests were chosen to simulate actual kiln operation. A factorial experimental design made of the parameters of burning temperature, lime content, and lumina (flux) content. Preliminary results from this study indicate that a raw mix made from the sinter residue yields a satisfactory cement.

  9. Lunar cement

    NASA Technical Reports Server (NTRS)

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  10. Freshwater-phreatic calcite cementation, Schooner Cays, Bahamas

    SciTech Connect

    Budd, D.A.

    1985-02-01

    Freshwater-phreatic calcite cementation is an active process on 700 and 2700 yr-old ooid-sand islands in the Schooner Cays, Bahamas. Cement fabrics and textures indicate a general, four-stage model of pore infilling. (1) The precipitation of isolated, decimicron-sized, rhombohedrons of calcite on grain surfaces forms an incipient circumgranular cement. (2) Continued precipitation enlarges crystal sizes and forms new rhombohedral crystals, resulting in a continuous circumgranular rim of cement. (3) Additional cementation quickly masks the circumgranular fabric, producing a partial pore-filling mosaic. (4) The remaining pore space is occluded with a mosaic of calcite cement. Petrographic evidence for the earlier circumgranular rim of cement is not necessarily apparent after the last stage of cementation. Empty pores and all four stages of phreatic-zone cementation were observed in the diagenetically immature 700 yr-old rocks, but only stages 2 through 4 were observed in the diagenetically more mature 2700 yr-old phreatic zone samples. Cements are distributed homogeneously within each pore at every stage, yet because each pore may proceed through the four stages at different rates, each pore can be at a different stage of infilling. This results in an inhomogeneous distribution of cement between pores during the initial stages of cementation. Recognition of a cement stratigraphy similar to that described here should aid in the identification of freshwater-phreatic diagenesis in ancient carbonate rock sequences. Variability in the amount of freshwater-phreatic cement between pores should be expected and not interpreted as the product of different paragenetic sequences.

  11. EVALUATION OF PRIMARY AIR VITIATION FOR NITRIC OXIDE REDUCTION IN A ROTARY CEMENT KILN. VOLUME 2. DATA SUPPLEMENT A

    EPA Science Inventory

    The report gives results of tests to evaluate combustion modifications for nitric oxide (NO) reduction and cement product quality in a pilot-scale long-dry-process cement kiln firing pulverized coal. The kiln is rated at 11.35 kg/s (1080 tons/day) of cement with a thermal input r...

  12. EVALUATION OF PRIMARY AIR VITIATION FOR NITRIC OXIDE REDUCTION IN A ROTARY CEMENT KILN. VOLUME 3. DATA SUPPLEMENT B

    EPA Science Inventory

    The report gives results of tests to evaluate combustion modifications for nitric oxide (NO) reduction and cement product quality in a pilot-scale long-dry-process cement kiln firing pulverized coal. The kiln is rated at 11.35 kg/s (1080 tons/day) of cement with a thermal input r...

  13. EVALUATION OF PRIMARY AIR VITIATION FOR NITRIC OXIDE REDUCTION IN A ROTARY CEMENT KILN. VOLUME 1. TECHNICAL REPORT

    EPA Science Inventory

    The report gives results of tests to evaluate combustion modifications for nitric oxide (NO) reduction and cement product quality in a pilot-scale long-dry-process cement kiln firing pulverized coal. The kiln is rated at 11.35 kg/s (1080 tons/day) of cement with a thermal input r...

  14. Process to Product.

    ERIC Educational Resources Information Center

    Harrison, Gary, Ed.; Mirkes, Donna Z., Ed.

    Intended for educators who direct federally funded model projects, the booklet provides a framework for special education product development. In "Making Media Decisions," G. Richman explores procedures for selecting the most appropriate medium to carry the message of a given product. The fundamental questions are addressed: what is the goal; who

  15. Fan System Optimization Improves Production and Saves Energy at Ash Grove Cement Plant

    SciTech Connect

    2002-05-01

    This case study describes an optimization project implemented on a fan system at Ash Grove Cement Company, which led to annual energy and maintenance savings of $16,000 and 175,000 kilowatt-hours (kWh).

  16. Leaching of metals from cement under simulated environmental conditions.

    PubMed

    Lu, Huixia; Wei, Fang; Tang, Jingchun; Giesy, John P

    2016-03-15

    Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambient environment and particle size on leachability of metals and mineralogical phases of cement mortars were evaluated by use of XRD and SEM. Results indicated that metals in cements were leachable in various media in descending order of: sea water, groundwater and acid rain. Cr, Ni, As, Co and V were leached by simulated sea water, while Cu, Cd, Pb, Zn, Mn, Sb and Tl were not leached in simulated sea water, groundwater or acid rain. When exposed to simulated acid rain or groundwater, amounts of Cr, Ni, As and V leached was inversely proportional to particle size of cement mortar. According to the one-dimensional diffusion equation, Cr was most leachable and the cumulative leached mass was predicted to be 9.6 mg kg(-1) after 20 years. Results of this study are useful in predicting releases of metals from cement products containing ash and clinkers cement kiln co-processing of hazardous wastes, so that they can be safely applied in the environment. PMID:26802528

  17. Evaluation of Life-Cycle Assessment Studies of Chinese Cement Production: Challenges and Opportunities

    SciTech Connect

    Lu, Hongyou; Masanet, Eric; Price, Lynn

    2009-05-29

    The use of life-cycle assessment (LCA) to understand the embodied energy, environmental impacts, and potential energy-savings of manufactured products has become more widespread among researchers in recent years. This paper reviews recent LCA studies in the cement industry in China and in other countries and provides an assessment of the methodology used by the researchers compared to ISO LCA standards (ISO 14040:2006, ISO 14044:2006, and ISO/TR 14048:2002). We evaluate whether the authors provide information on the intended application, targeted audience, functional unit, system boundary, data sources, data quality assessment, data disaggregation and other elements, and draw conclusions regarding the level of adherence to ISO standards for the papers reviewed. We found that China researchers have gained much experience during last decade, but still have room for improvement in establishing boundaries, assessing data quality, identifying data sources, and explaining limitations. The paper concludes with a discussion of directions for future LCA research in China.

  18. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The chemical engineering analysis of the preliminary process design of a process for producing solar cell grade silicon from dichlorosilane is presented. A plant to produce 1,000 MT/yr of silicon is analyzed. Progress and status for the plant design are reported for the primary activities of base case conditions (60 percent), reaction chemistry (50 percent), process flow diagram (35 percent), energy balance (10 percent), property data (10 percent) and equipment design (5 percent).

  19. Neutron Scattering Studies of Cement

    NASA Astrophysics Data System (ADS)

    Allen, Andrew

    2010-03-01

    Despite more than a century of research, basic questions remain regarding both the internal structure and the role of water in Ordinary Portland cement (OPC) concrete, the world's most widely used manufactured material. Most such questions concern the primary hydration product and strength-building phase of OPC paste, the calcium silicate hydrate (C-S-H) gel. When cement and water are mixed, this phase precipitates as clusters of nanoscale (nearly amorphous) colloidal particles with an associated water-filled inter-particle pore system. Most attempts to characterize the C-S-H gel and the behavior of the associated water involve drying or other processes that, themselves, change the bound water content within and around the gel. Neutron scattering methods do not suffer from this disadvantage. Furthermore, the neutron isotope effect and the neutron's sensitivity to molecular motion have enabled considerable progress to be made in recent years by: (i) determining the C-S-H composition, density and gel structure in small-angle neutron scattering (SANS) H/D contrast variation studies; (ii) elucidating the changing state of water within cement as hydration progresses using quasielastic neutron scattering (QENS); and (iii) measuring the production and consumption of nanoscale calcium hydroxide (CH), a by-product of cement hydration that co-exists with the C-S-H gel, using inelastic neutron scattering (INS). These experiments have provided new insights into the physics and chemistry of cement hydration, and have implications for the design of new concretes with pozzolanic cement additions that are intended to address environmental concerns and sustainability issues.

  20. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Chemical engineering analysis of the HSC process (Hemlock Semiconductor Corporation) for producing silicon from dichlorosilane in a 1,000 MT/yr plant was continued. Progress and status for the chemical engineering analysis of the HSC process are reported for the primary process design engineering activities: base case conditions (85%), reaction chemistry (85%), process flow diagram (60%), material balance (60%), energy balance (30%), property data (30%), equipment design (20%) and major equipment list (10%). Engineering design of the initial distillation column (D-01, stripper column) in the process was initiated. The function of the distillation column is to remove volatile gases (such as hydrogen and nitrogen) which are dissolved in liquid chlorosilanes. Initial specifications and results for the distillation column design are reported including the variation of tray requirements (equilibrium stages) with reflux ratio for the distillation.

  1. Silicon production process evaluations

    NASA Astrophysics Data System (ADS)

    1981-12-01

    Chemical engineering analysis of the HSC process (Hemlock Semiconductor Corporation) for producing silicon from dichlorosilane in a 1,000 MT/yr plant was continued. Progress and status for the chemical engineering analysis of the HSC process are reported for the primary process design engineering activities: base case conditions (85%), reaction chemistry (85%), process flow diagram (60%), material balance (60%), energy balance (30%), property data (30%), equipment design (20%) and major equipment list (10%). Engineering design of the initial distillation column (D-01, stripper column) in the process was initiated. The function of the distillation column is to remove volatile gases (such as hydrogen and nitrogen) which are dissolved in liquid chlorosilanes. Initial specifications and results for the distillation column design are reported including the variation of tray requirements (equilibrium stages) with reflux ratio for the distillation.

  2. The processing, mechanical properties and bioactivity of strontium based glass polyalkenoate cements.

    PubMed

    Wren, Anthony; Boyd, Daniel; Towler, M R

    2008-04-01

    The suitability of zinc-based glass polyalkenoate cements (GPCs) for use in orthopaedics can be improved by the substitution of strontium into the glass phase which should impart improved radiopacity and bone forming properties to the cements without retarding strength. The purpose of this research was to produce novel GPCs based on calcium-strontium-zinc-silicate glasses and to evaluate their mechanical properties and biocompatibility with the ultimate objective of developing a new range of cements for skeletal applications. Three glass compositions, based on incremental substitutions of strontium for calcium, were synthesized; BT100 (0.16CaO, 0.36ZnO, 0.48SiO2), BT101 (0.04SrO, 0.12CaO, 0.36ZnO, 0.48SiO2) and BT102 (0.08SrO 0.08CaO, 0.36ZnO, 0.48SiO2). Each glass was then mixed with varying concentrations and molecular weights of polyacrylic acids in order to determine the working times, setting times, compressive strengths and biaxial flexural strengths of the novel cements. The maximum working time and setting time achieved was 29 and 110 s respectively; which, at present is inadequate for current clinical procedures. However, the optimum compressive and biaxial flexural strengths were up to 75 and 34 MPa respectively indicating that these formulations have potential in load bearing applications. Importantly, the substitution of Ca with Sr in the glasses did not have a deleterious effect on strengths or working times. Finally, the bioactivity of the best performing cements was determined in vitro using simulated body fluid. It was found that all cements facilitate the formation of an amorphous calcium phosphate at their surface which increases in density and coverage with time, indicating that these cement will bond directly to bone in vivo. PMID:17943414

  3. Utilization of municipal solid waste incineration fly ash for sulfoaluminate cement clinker production

    SciTech Connect

    Wu Kai; Shi Huisheng; Guo Xiaolu

    2011-09-15

    Highlights: > The replacement can be taken up to 30% of MSWI fly ash in the raw mix. > The novelty compositional parameters were defined, their optimum values were determined. > Expansive property of SAC is strongly depended on gypsum content. > Three leaching test methods are used to assess the environmental impact. - Abstract: The feasibility of partially substituting raw materials with municipal solid waste incineration (MSWI) fly ash in sulfoaluminate cement (SAC) clinker production was investigated by X-ray diffraction (XRD), compressive strength and free expansion ratio testing. Three different leaching tests were used to assess the environmental impact of the produced material. Experimental results show that the replacement of MSWI fly ash could be taken up to 30% in the raw mixes. The good quality SAC clinkers are obtained by controlling the compositional parameters at alkalinity modulus (C{sub m}) around 1.05, alumina-sulfur ratio (P) around 2.5, alumina-silica ratio (N) around 2.0{approx}3.0 and firing the raw mixes at 1250 deg. C for 2 h. The compressive strengths of SAC are high in early age while that develop slowly in later age. Results also show that the expansive properties of SAC are strongly depended on the gypsum content. Leaching studies of toxic elements in the hydrated SAC-based system reveal that all the investigated elements are well bounded in the clinker minerals or immobilized by the hydration products. Although some limited positive results indicate that the SAC prepared from MSWI fly ash would present no immediate thread to the environment, the long-term toxicity leaching behavior needs to be further studied.

  4. A thermodynamic model for blended cements. II: Cement hydrate phases; thermodynamic values and modelling studies

    NASA Astrophysics Data System (ADS)

    Bennett, D. G.; Read, D.; Atkins, M.; Glasser, F. P.

    1992-08-01

    Blended Portland cements are likely to form a substantial proportion of repository materials for the disposal of radioactive waste in the UK. A thermodynamic model has been developed therefore in order to predict the composition of the solid and aqueous phases in blended cements as a function of the bulk cement composition. The model is based on simplifying cement to the system CaO sbnd SiO 2sbnd Al 2O 3sbnd SO 4sbnd MgO sbnd H 2O, which constitutes 95% of most cement formulations. Solubility data for hydrogarnet and ettringite suggest that they dissolve congruently and that conventional solubility products can be used to model their dissolution. A solubility model for the siliceous hydrogarnet series, based on ideal solid solution on either side of an immiscibility gap, closely matches experimental solubility data. Solubility data for hydrotalcite and gehlenite hydrate are less consistent and indicative of more complex dissolution processes. On the basis of earlier work, an accurate solubility model is described for hydrated calcium silicate gels in the CaO sbnd SiO 2sbnd H 2O system. Together, these solubility models form a relatively complete thermodynamic model for blended cements. Model predictions for fully matured cement blends are compared to the compositions of pore fluids extracted from aged cement blends. Departures from expected behaviour occur in alkali-bearing systems and are discussed.

  5. Event cementation in sandstones

    SciTech Connect

    Robinson, A. ); Gluyas, J. )

    1991-08-01

    Precipitation of quartz overgrowths on sand grains is a common cause of porosity reduction in sandstones. The amount of quartz overgrowths (cement) often increases with depth so that the process of cementation is generally considered to be a direct response to burial and to proceed throughout the burial history of a sandstone. The authors show that some Mesozoic and Cenozoic sandstones are cemented during events 1-10 m.y. in length, periods one to two orders of magnitude less than their burial histories. Burial alone is unlikely to be the cause of quartz cementation. This new knowledge should markedly change our perception of porosity evolution in sandstones.

  6. Silicon production process evaluations

    NASA Astrophysics Data System (ADS)

    1982-02-01

    Chemical engineering analysis was continued for the HSC process (Hemlock Semiconductor Corporation) in which solar cell silicon is produced in a 1,000 MT/yr plant. Progress and status are reported for the primary engineering activities involved in the preliminary process engineering design of the plant base case conditions (96%), reaction chemistry (96%), process flow diagram (85%), material balance (85%), energy balance (60%), property data (60%), equipment design (40%), major equipment list (30%) and labor requirements (10%). Engineering design of the second distillation column (D-02, TCS column) in the process was completed. The design is based on a 97% recovery of the light key (TCS, trichlorosilane) in the distillate and a 97% recovery of the heavy key (TET, silicon tetrachloride) in the bottoms. At a reflux ratio of 2, the specified recovery of TCS and TET is achieved with 20 trays (equilibrium stages, N=20). Respective feed tray locations are 9, 12 and 15 (NF sub 1 = 9, NF sub 2 = 12,, and NF sub 3 = 15). A total condenser is used for the distillation which is conducted at a pressure of 90 psia.

  7. Silicon production process evaluations

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Chemical engineering analysis was continued for the HSC process (Hemlock Semiconductor Corporation) in which solar cell silicon is produced in a 1,000 MT/yr plant. Progress and status are reported for the primary engineering activities involved in the preliminary process engineering design of the plant base case conditions (96%), reaction chemistry (96%), process flow diagram (85%), material balance (85%), energy balance (60%), property data (60%), equipment design (40%), major equipment list (30%) and labor requirements (10%). Engineering design of the second distillation column (D-02, TCS column) in the process was completed. The design is based on a 97% recovery of the light key (TCS, trichlorosilane) in the distillate and a 97% recovery of the heavy key (TET, silicon tetrachloride) in the bottoms. At a reflux ratio of 2, the specified recovery of TCS and TET is achieved with 20 trays (equilibrium stages, N=20). Respective feed tray locations are 9, 12 and 15 (NF sub 1 = 9, NF sub 2 = 12,, and NF sub 3 = 15). A total condenser is used for the distillation which is conducted at a pressure of 90 psia.

  8. The use of electrical impedance spectroscopy for monitoring the hydration products of Portland cement mortars with high percentage of pozzolans

    SciTech Connect

    Cruz, J.M.; Fita, I.C.; Soriano, L.; Payá, J.; Borrachero, M.V.

    2013-08-15

    In this paper, mortars and pastes containing large replacement of pozzolan were studied by mechanical strength, thermogravimetric analysis (TGA), scanning electronic microscopy (SEM), mercury intrusion porosimetry (MIP) and electrical impedance spectroscopy (EIS). The effect of metakaolin (35%) and fly ash (60%) was evaluated and compared with an inert mineral addition (andalusite). The portlandite content was measured, finding that the pozzolanic reaction produced cementing systems with all portlandite fixed. The EIS measurements were analyzed by the equivalent electrical circuit (EEC) method. An EEC with three branches in parallel was applied. The dc resistance was related to the degree of hydration and allowed us to characterize plain and blended mortars. A constant phase element (CPE) quantified the electrical properties of the hydration products located in the solid–solution interface and was useful to distinguish the role of inert and pozzolanic admixtures present in the cement matrix.

  9. Plasma Spray and Pack Cementation Process Optimization and Oxidation Behaviour of Novel Multilayered Coatings

    NASA Astrophysics Data System (ADS)

    Gao, Feng

    The hot section components in gas turbines are subjected to a harsh environment with the temperature being increased continuously. The higher temperature has directly resulted in severe oxidation of these components. Monolithic coatings such as MCrAIY and aluminide have been traditionally used to protect the components from oxidation; however, increased operating temperature quickly deteriorates the coatings due to accelerated diffusion of aluminum in the coatings. To improve the oxidation resistance a group of multilayered coatings are developed in this study. The multilayered coatings consist of a Cr-Si co-deposited layer as the diffusion barrier, a plasma sprayed NiCrA1Y coating as the middle layer and an aluminized top layer. The Cr-Si and aluminized layers are fabricated using pack cementation processes and the NiCrA1Y coatings are produced using the Mettech Axial III(TM) System. All of the coating processes are optimized using the methodology of Design of Experiments (DOE) and the results are analyzed using statistical method. The optimal processes are adopted to fabricate the multilayered coatings for oxidation tests. The coatings are exposed in air at 1050C and 1150C for 1000 hr. The results indicate that a Cr layer and a silicon-rich barrier layer have formed on the interface between the Cr-Si coating and the NiCrA1Y coating. This barrier layer not only prevents aluminum and chromium from diffusing into the substrate, but also impedes the diffusion of other elements from the substrate into the coating. The results also reveal that, for optimal oxidation resistance at 1050C, the top layer in a multilayered coating should have at least Al/Ni ratio of one; whereas the multilayered coating with the All Ni ratio of two in the top layer exhibits the best oxidation resistance at 1150C. The DOE methodology provides an excellent means for process optimization and the selection of oxidation test matrix, and also offers a more thorough understanding of the effects of process parameters on the coating microstructure, and the effects of layers and their interactions on the oxidation behavior of the multilayered coatings.

  10. NASA Product Peer Review Process

    NASA Technical Reports Server (NTRS)

    Jenks, Ken

    2009-01-01

    This viewgraph presentation describes NASA's product peer review process. The contents include: 1) Inspection/Peer Review at NASA; 2) Reasons for product peer reviews; 3) Different types of peer reviews; and 4) NASA requirements for peer reviews. This presentation also includes a demonstration of an actual product peer review.

  11. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi (Mastic Beach, NY)

    1989-01-01

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed.

  12. Reducing cement's CO2 footprint

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  13. High temperature lightweight foamed cements

    DOEpatents

    Sugama, Toshifumi.

    1989-10-03

    Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

  14. Comparison of modified sulfur cement and hydraulic cement for encapsulation of radioactive and mixed wastes

    SciTech Connect

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1990-01-01

    The majority of solidification/stabilization systems for low-level radioactive waste (LLW) and mixed waste, both in the commercial sector and at Department of Energy (DOE) facilities, utilize hydraulic cement (such as portland cement) to encapsulate waste materials and yield a monolithic solid waste form for disposal. A new and innovative process utilizing modified sulfur cement developed by the US Bureau of Mines has been applied at Brookhaven National Laboratory (BNL) for the encapsulation of many of these problem'' wastes. Modified sulfur cement is a thermoplastic material, and as such, it can be heated above it's melting point (120{degree}C), combined with dry waste products to form a homogeneous mixture, and cooled to form a monolithic solid product. Under sponsorship of the DOE, research and development efforts at BNL have successfully applied the modified sulfur cement process for treatment of a range of LLWs including sodium sulfate salts, boric acid salts, and incinerator bottom ash and for mixed waste contaminated incinerator fly ash. Process development studies were conducted to determine optimal waste loadings for each waste type. Property evaluation studies were conducted to test waste form behavior under disposal conditions by applying relevant performance testing criteria established by the Nuclear Regulatory Commission (for LLW) and the Environmental Protection Agency (for hazardous wastes). Based on both processing and performance considerations, significantly greater waste loadings were achieved using modified sulfur cement when compared with hydraulic cement. Technology demonstration of the modified sulfur cement encapsulation system using production-scale equipment is scheduled for FY 1991. 12 refs., 8 figs., 3 tabs.

  15. Leaching of hazardous substances from a composite construction product--an experimental and modelling approach for fibre-cement sheets.

    PubMed

    Lupsea, Maria; Tiruta-Barna, Ligia; Schiopu, Nicoleta

    2014-01-15

    The leaching behaviour of a commercial fibre-cement sheet (FCS) product has been investigated. A static pH dependency test and a dynamic surface leaching test have been performed at lab scale. These tests allowed the development of a chemical-transport model capable to predict the release of major and trace elements over the entire pH range, in function of time. FCS exhibits a cement-type leaching behaviour with respect to the mineral species. Potentially hazardous species are released in significant quantities when compared to their total content. These are mainly heavy metals commonly encountered in cement matrixes and boron (probably added as biocide). Organic compounds considered as global dissolved carbon are released in significant concentrations, originating probably from the partial degradation of the organic fibres. The pesticide terbutryn (probably added during the preservative treatment of the organic fibres) was systematically identified in the leachates. The simulation of an upscaled runoff scenario allowed the evaluation of the cumulative release over long periods and the distribution of the released quantities in time, in function of the local exposure conditions. After 10 years of exposure the release reaches significant fractions of the species' total content - going from 4% for Cu to near 100% for B. PMID:24295776

  16. Recovery Act Production of Algal BioCrude Oil from Cement Plant Carbon Dioxide

    SciTech Connect

    Robert Weber; Norman Whitton

    2010-09-30

    The consortium, led by Sunrise Ridge Algae Inc, completed financial, legal, siting, engineering and environmental permitting preparations for a proposed demonstration project that would capture stack gas from an operating cement plant and convert the carbon dioxide to beneficial use as a liquid crude petroleum substitute and a coal substitute, using algae grown in a closed system, then harvested and converted using catalyzed pyrolysis.

  17. Case Study of the California Cement Industry

    SciTech Connect

    Coito, Fred; Powell, Frank; Worrell, Ernst; Price, Lynn; Friedmann, Rafael

    2005-05-01

    California is the largest cement producing state in theU.S., accounting for between 10 percent and 15 percent of U.S. cementproduction and cement industry employment. The cement industry inCalifornia consists of 31 sites that consume large amounts of energy,annually: 1,600 GWh of electricity, 22 million therms of natural gas, 2.3million tons of coal, 0.25 tons of coke, and smaller amounts of wastematerials, including tires. The case study summarized in this paperfocused on providing background information, an assessment ofenergy-efficiency opportunities and barriers, and program recommendationsthat can be used by program planners to better target products to thecement industry. The primary approach to this case study involvedwalk-through surveys of customer facilities and in depth interviews withcustomer decision makers and subsequent analysis of collected data. Inaddition, a basic review of the cement production process was developed,and summary cement industry energy and economic data were collected, andanalyzed. The analysis of secondary data provides background informationon the cement industry and identification of potential energy-efficiencyopportunities. The interviews provide some understanding of the customerperspective about implementation of energy-efficiencyprojects.

  18. Products and Processes: Synergistic Relationships

    ERIC Educational Resources Information Center

    Wallace, Virginia; Husid, Whitney

    2013-01-01

    Most people agree that products are the culmination of what students have studied. For this article, "product" will refer to students' abilities to create outcomes and design artifacts. Those abilities are guided by four processes: inquiry-based learning, use of a research model, use of Web 2.0 tools, and appropriate assessments.

  19. International Best Practices for Pre-Processing and Co-Processing Municipal Solid Waste and Sewage Sludge in the Cement Industry

    SciTech Connect

    Hasanbeigi, Ali; Lu, Hongyou; Williams, Christopher; Price, Lynn

    2012-07-01

    The purpose of this report is to describe international best practices for pre-processing and coprocessing of MSW and sewage sludge in cement plants, for the benefit of countries that wish to develop co-processing capacity. The report is divided into three main sections. Section 2 describes the fundamentals of co-processing, Section 3 describes exemplary international regulatory and institutional frameworks for co-processing, and Section 4 describes international best practices related to the technological aspects of co-processing.

  20. Copper-promoted cementation of antimony in hydrochloric acid system: A green protocol.

    PubMed

    Wu, Lian-Kui; Li, Ying-Ying; Cao, Hua-Zhen; Zheng, Guo-Qu

    2015-12-15

    A new method of recovering antimony in hydrochloric acid system by cementation with copper powder was proposed and carried out at laboratory scale. Thermodynamic analysis and cyclic voltammetry test were conducted to study the cementation process. This is a novel antimony removal technology and quite meets the requirements of green chemistry. The main cement product Cu2Sb is a promising anodic material for lithium and sodium ion battery. And nearly all consumed copper powder are transformed into CuCl which is an important industrial material. The effect of reaction temperature, stoichiometric ratio of Cu to Sb(III), stirring rate and concentration of HCl on the cementation efficiency of antimony were investigated in detail. Optimized cementation condition is obtained at 60°C for 120min and stirring rate of 600rpm with Cu/Sb(III) stoichiometric ratio of 6 in 3molL(-1) HCl. At this time, nearly all antimony can be removed by copper powder and the cementation efficiency is over 99%. The structure and morphologies of the cement products were characterized by X-ray diffraction and scanning electron microscopy, respectively. Results show that the reaction temperature has little influence on the morphology of the cement products which consist of particles with various sizes. The activation energy of the cementation antimony on copper is 37.75kJmol(-1), indicating a chemically controlled step. Inductively coupled plasma mass spectrometry results show that no stibine generates during the cementation process. PMID:26252996

  1. TESOL's Process Versus Product Debate.

    ERIC Educational Resources Information Center

    Shannon, John

    The controversy over two approaches to writing instruction in English as a Second Language (ESL), product and process orientations, is reviewed based on articles appearing in the Teachers of English to Speakers of Other Languages' quarterly professional journal from 1982-1991. In the process-oriented approach, instructional practices emphasize the

  2. Interfacial ultramorphology evaluation of resin luting cements to dentin: a correlative scanning electron microscopy and transmission electron microscopy analysis.

    PubMed

    Aguiar, Thaiane Rodrigues; Vermelho, Paulo Moreira; Andr, Carolina Bosso; Giannini, Marcelo

    2013-12-01

    The objective of this study was to analyze the dentin-resin cements interfacial ultramorphologies using two different methods: scanning (SEM) and transmission electron microscopy (TEM). Four commercial products were evaluated: two conventional cementing system (RelyX ARC/Adper Scotchbond Multi-Purpose Plus, 3M ESPE and Clearfil Esthetic Cement/DC Bond, Kuraray) and two self-adhesive resin cements (RelyX Unicem, 3M ESPE and Clearfil SA Cement, Kuraray). Prepolymerized resin disks (Sinfony, 3M ESPE) were cemented on oclusal dentin surfaces of 24 third human molars, simulating the indirect restorations. After 24 h, teeth were sectioned into 0.9-mm thick slabs and processed for microscopy analyses (SEM or TEM/ n = 3). Qualitative characterization of dentin-resin cement interface was performed. Hybrid layer formation with long and dense resin tags was observed only for RelyX ARC cementing system. Clearfil Esthetic Cement/DC Bond system revealed few and short resin tags formation, whereas no hybridization and resin tags were detected for self-adhesive resin cements. Some interfacial regions exhibited that the self-adhesive resin cements were not bonded to dentin, presenting bubbles or voids at the interfaces. In conclusion, TEM and SEM bonding interface analyses showed ultramorphological variations among resin cements, which are directly related to dental bonding strategies used for each resin cement tested. PMID:24030836

  3. Modeling Production Plant Forming Processes

    SciTech Connect

    Rhee, M; Becker, R; Couch, R; Li, M

    2004-09-22

    Engineering has simulation tools and experience in modeling forming processes. Y-12 personnel have expressed interest in validating our tools and experience against their manufacturing process activities such as rolling, casting, and forging etc. We have demonstrated numerical capabilities in a collaborative DOE/OIT project with ALCOA that is nearing successful completion. The goal was to use ALE3D to model Alcoa's slab rolling process in order to demonstrate a computational tool that would allow Alcoa to define a rolling schedule that would minimize the probability of ingot fracture, thus reducing waste and energy consumption. It is intended to lead to long-term collaboration with Y-12 and perhaps involvement with other components of the weapons production complex. Using simulations to aid in design of forming processes can: decrease time to production; reduce forming trials and associated expenses; and guide development of products with greater uniformity and less scrap.

  4. (31)P Solid-State NMR study of the chemical setting process of a dual-paste injectable brushite cements.

    PubMed

    Legrand, A P; Sfihi, H; Lequeux, N; Lematre, J

    2009-10-01

    The composition and evolution of a brushite-type calcium phosphate cement was investigated by Solid-State NMR and X-ray during the setting process. The cement is obtained by mixing beta-tricalcium phosphate [Ca(3)(PO(4))(2), beta-TCP] and monocalcium phosphate monohydrate [Ca(H(2)PO(4))(2).H(2)O, MCPM] in presence of water, with formation of dicalcium phosphate dihydrate or brushite [CaHPO(2).2H(2)O, DCPD]. Analysis of the initial beta-TCP paste has shown the presence of beta-calcium pyrophosphate [Ca(2)P(2)O(7), beta-CPy] and that of the initial MCPM a mixture of MCPM and dicalcium phosphate [CaHPO(4), DCP]. Follow-up of the chemical composition by (31)P Solid-State NMR enables to show that the chemical setting process appeared to reach an end after 20 min. The constant composition observed at the end of the process was similarly determined. PMID:19365821

  5. Cement composition and sulfate attack

    SciTech Connect

    Shanahan, Natalya; Zayed, Abla . E-mail: zayed@eng.usf.edu

    2007-04-15

    Four cements were used to address the effect of tricalcium silicate content of cement on external sulfate attack in sodium sulfate solution. The selected cements had similar fineness and Bogue-calculated tricalcium aluminate content but variable tricalcium silicates. Durability was assessed using linear expansion and compressive strength. Phases associated with deterioration were examined using scanning electron microscopy and X-ray diffraction. Mineralogical phase content of the as-received cements was studied by X-ray diffraction using two methods: internal standard and Rietveld analysis. The results indicate that phase content of cements determined by X-ray mineralogical analysis correlates better with the mortar performance in sulfate environment than Bogue content. Additionally, it was found that in cements containing triclacium aluminate only in the cubic form, the observed deterioration is affected by tricalcium silicate content. Morphological similarities between hydration products of high tricalcium aluminate and high tricalcium silicate cements exposed to sodium sulfate environment were also observed.

  6. Energy savings by improved control of the finish grinding process in cement manufacture: Final report, January 1, 1985-December 31, 1986

    SciTech Connect

    Weiss, S.J.; Tresouthick, S.W.

    1987-03-01

    Conventional closed-circuit ball mill systems for the finish grinding of portland cement produces product particle size distributions (PSDs) which indicate poor reduction of topsize and excessive production of fines. Optimization of ball mill systems should improve energy efficiency while meeting or exceeding typical cement performance requirements. Pilot scale continuous grinding systems, including a closed-circuit ball mill with a conventional classifier, a high-efficiency classifier, or a vertical roller mill were used to determine operating conditions and configurations which would lead to narrowing of the cement PSD. Closed-circuit ball mill results suggest that several opportunities exist to increase particle breakage efficiencies while minimizing unnecessary fines generation by means such as: modification of mill recirculation rates, optimal selection of ball size distribution, and use of highly efficient particle size classifiers. Mill system design philosophies common worldwide which favor long mill lengths, fine ball charges, and low circulating loads are called into question. In order to produce cements with acceptable early mortar strengths by sole use of a roller mill, products must be ground to finenesses similar to those of conventional cements.

  7. Predicting the Impact of Multiwalled Carbon Nanotubes on the Cement Hydration Products and Durability of Cementitious Matrix Using Artificial Neural Network Modeling Technique

    PubMed Central

    Fakhim, Babak; Hassani, Abolfazl; Rashidi, Alimorad; Ghodousi, Parviz

    2013-01-01

    In this study the feasibility of using the artificial neural networks modeling in predicting the effect of MWCNT on amount of cement hydration products and improving the quality of cement hydration products microstructures of cement paste was investigated. To determine the amount of cement hydration products thermogravimetric analysis was used. Two critical parameters of TGA test are PHPloss and CHloss. In order to model the TGA test results, the ANN modeling was performed on these parameters separately. In this study, 60% of data are used for model calibration and the remaining 40% are used for model verification. Based on the highest efficiency coefficient and the lowest root mean square error, the best ANN model was chosen. The results of TGA test implied that the cement hydration is enhanced in the presence of the optimum percentage (0.3 wt%) of MWCNT. Moreover, since the efficiency coefficient of the modeling results of CH and PHP loss in both the calibration and verification stages was more than 0.96, it was concluded that the ANN could be used as an accurate tool for modeling the TGA results. Another finding of this study was that the ANN prediction in higher ages was more precise. PMID:24489487

  8. Energy Efficiency Improvement Opportunities for the Cement Industry

    SciTech Connect

    Price, Lynn; Worrell, Ernst; Galitsky, Christina; Price, Lynn

    2008-01-31

    This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists all measures in this report by process to which they apply, including plant wide measures and product or feedstock changes. Tables 2 through 8 provide the following information for each technology: fuel and electricity savings per tonne of cement; annual operating and capital costs per tonne of cement or estimated payback period; and, carbon dioxide emissions reductions for each measure applied to the production of cement. This information was originally collected for a report on the U.S. cement industry (Worrell and Galitsky, 2004) and a report on opportunities for China's cement kilns (Price and Galitsky, in press). The information provided in this report is based on publicly-available reports, journal articles, and case studies from applications of technologies around the world.

  9. Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

    SciTech Connect

    Olsen, Daniel; Goli, Sasank; Faulkner, David; McKane, Aimee

    2010-12-22

    This study examines the characteristics of cement plants and their ability to shed or shift load to participate in demand response (DR). Relevant factors investigated include the various equipment and processes used to make cement, the operational limitations cement plants are subject to, and the quantities and sources of energy used in the cement-making process. Opportunities for energy efficiency improvements are also reviewed. The results suggest that cement plants are good candidates for DR participation. The cement industry consumes over 400 trillion Btu of energy annually in the United States, and consumes over 150 MW of electricity in California alone. The chemical reactions required to make cement occur only in the cement kiln, and intermediate products are routinely stored between processing stages without negative effects. Cement plants also operate continuously for months at a time between shutdowns, allowing flexibility in operational scheduling. In addition, several examples of cement plants altering their electricity consumption based on utility incentives are discussed. Further study is needed to determine the practical potential for automated demand response (Auto-DR) and to investigate the magnitude and shape of achievable sheds and shifts.

  10. Hydrocracking process for aromatics production

    SciTech Connect

    Derr, W.R.; Sarli, M.S.

    1984-03-06

    A hydrocracking process with improved distillate selectivity is operated at limited conversion without liquid/gas separation between the denitrogenation and hydrocracking catalyst beds or liquid recycle. Conversion is held to a maximum of 50 volume percent to lower boiling products. Relatively mild conditions, especially of pressure, may be employed.

  11. Discovery Reconceived: Product before Process

    ERIC Educational Resources Information Center

    Abrahamson, Dor

    2012-01-01

    Motivated by the question, "What exactly about a mathematical concept should students discover, when they study it via discovery learning?", I present and demonstrate an interpretation of discovery pedagogy that attempts to address its criticism. My approach hinges on decoupling the solution process from its resultant product. Whereas theories of

  12. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  13. Thermodynamics and cement science

    SciTech Connect

    Damidot, D.; Lothenbach, B.; Herfort, D.; Glasser, F.P.

    2011-07-15

    Thermodynamics applied to cement science has proved to be very valuable. One of the most striking findings has been the extent to which the hydrate phases, with one conspicuous exception, achieve equilibrium. The important exception is the persistence of amorphous C-S-H which is metastable with respect to crystalline calcium silicate hydrates. Nevertheless C-S-H can be included in the scope of calculations. As a consequence, from comparison of calculation and experiment, it appears that kinetics is not necessarily an insuperable barrier to engineering the phase composition of a hydrated Portland cement. Also the sensitivity of the mineralogy of the AFm and AFt phase compositions to the presence of calcite and to temperature has been reported. This knowledge gives a powerful incentive to develop links between the mineralogy and engineering properties of hydrated cement paste and, of course, anticipates improvements in its performance leading to decreasing the environmental impacts of cement production.

  14. Modern production process for magnesium

    SciTech Connect

    Wilson, C.B.

    1996-10-01

    There are currently two major routes practiced industrially for the production of primary magnesium metal. The first of these is the electrolysis of magnesium chloride and the second is the thermal reduction of magnesium oxide. Within these two major categories, there are many variations of the technologies in the industry. The dominant production method is the electrolysis of magnesium chloride and this is carried out by The Dow Chemical Company, Norsk Hydro, Magcorp, and the plants in the Former Soviet Union. Each of the processes at these facilities uses a different means of feed preparation and this in turn causes the electrolytic cell end of the processes to be different also. The second technology is the thermal reduction of magnesium oxide, and there are at least three different variations which are practiced industrially. The first of these is the Pidgeon process which reacts dolime (MgO{center_dot}CaO) with ferro-silicon (FeSi) to form a di-calcium silicate and magnesium metal at an elevated (about 1,200 C) temperature and reduced pressure in an externally heated retort. Timminco uses this process to produce a very high purity magnesium. The second process reacts the same starting raw materials at similar (about 1,250 C) temperatures in an internally heated reactor under reduced pressure. This is done by Brasmag in Brazil. The final variation of the ferro-silicon process is the Magnetherm{reg_sign} process developed by Pechiney and practiced by pechiney and Alcoa. This system uses slag resistance heating and very high (about 1,550 C) temperatures. This paper will examine each of these production methods and discuss both their merits and their weaknesses.

  15. Cobalt, titanium and PMMA bone cement debris influence on mouse osteoblast cell elasticity, spring constant and calcium production activity

    PubMed Central

    Preedy, Emily Callard; Perni, Stefano

    2015-01-01

    Periprosthetic osteolysis and implant loosening are the outcomes of wear debris generation in total joint replacements. Wear debris formed from the implanted materials consisting of metals, polymers, ceramic and bone cement initiate the immune system response. Often osteoblasts, the principal cell type in bone tissue adjacent to the prostheses, are directly impacted. In this study, the influence of cobalt, titanium and PMMA bone cement particles of different sizes, charges and compositions on mouse osteoblast adhesion, nanomechanics (elasticity and spring constant) and metabolic activity were investigated. These studies were accompanied by osteoblast mineralisation experiments and cell uptake after exposure to particles at defined time points. Our results demonstrate that alteration of the nanomechanical properties are mainly dependent on the metal type rather than nanoparticles size and concentration. Moreover, despite uptake increasing over exposure time, the cell characteristics exhibit changes predominately after the first 24 hours, highlighting that the cell responses to nanoparticle exposure are not cumulative. Understanding these processes is critical to expanding our knowledge of implant loosening and elucidating the nature of prosthetic joint failure.

  16. Utilization of industrial waste products as pozzolanic material in cemented paste backfill of high sulphide mill tailings.

    PubMed

    Ercikdi, Bayram; Cihangir, Ferdi; Kesimal, Ayhan; Deveci, Haci; Alp, Ibrahim

    2009-09-15

    In this study, the potential use of the industrial waste products including waste glass (WG), fly ash (FA), granulated blast furnace slag (GBFS) and silica fume (SF) as pozzolanic additive for the partial replacement of ordinary Portland cement (OPC) in cemented paste backfill (CPB) of sulphide-rich mill tailings was investigated. The influence of these industrial waste products on the short- and long-term mechanical performance of CPB was demonstrated. The rate of development of strength of CPB samples tended to slow down when the pozzolanic wastes were incorporated or increased in dosage in the binder phase. Severe losses (by 26%) in the strength of CPB samples produced from exclusively OPC occurred after an initial curing period of 56 days. The addition of WG (10-30 wt%) as a partial replacement of OPC was observed to aggravate further the strength losses of CPB samples. GBFS, FA and SF appeared to improve the long-term performance of CPB samples; albeit, only GBFS and SF could be incorporated into the binder phase only at certain levels i.e. up to 20 wt% GBFS and 15wt% SF in order to maintain a threshold strength level of 0.7MPa over 360 days. SEM studies have provided further insight into the microstucture of CPB and confirmed the formation of deleterious gypsum as the expansive phase. These findings have demonstrated that the industrial waste products including GBFS and SF can be suitably used as mineral additives to improve the long-term mechanical performance of CPB produced from sulphide-rich tailings as well as to reduce the binder costs in a CPB plant. PMID:19299080

  17. Process Flow Chart for Immobilizing of Radioactive High Concentration Sodium Hydroxide Product from the Sodium Processing Facility at the BN-350 Nuclear power plant in Aktau, Kazakhstan

    SciTech Connect

    Burkitbayev, M.; Omarova, K.; Tolebayev, T.; Galkin, A.; Bachilova, N.; Blynskiy, A.; Maev, V.; Wells, D.; Herrick, A.; Michelbacher, J.

    2008-07-01

    This paper describes the results of a joint research investigations carried out by the group of Kazakhstan, British and American specialists in development of a new material for immobilization of radioactive 35% sodium hydroxide solutions from the sodium coolant processing facility of the BN-350 nuclear power plant. The resulting solid matrix product, termed geo-cement stone, is capable of isolating long lived radionuclides from the environment. The physico-mechanical properties of geo-cement stone have been investigated and the flow chart for its production verified in a full scale experiments. (author)

  18. Synthesis: Intertwining product and process

    NASA Technical Reports Server (NTRS)

    Weiss, David M.

    1990-01-01

    Synthesis is a proposed systematic process for rapidly creating different members of a program family. Family members are described by variations in their requirements. Requirements variations are mapped to variations on a standard design to generate production quality code and documentation. The approach is made feasible by using principles underlying design for change. Synthesis incorporates ideas from rapid prototyping, application generators, and domain analysis. The goals of Synthesis and the Synthesis process are discussed. The technology needed and the feasibility of the approach are also briefly discussed. The status of current efforts to implement Synthesis methodologies is presented.

  19. The FGM Concept in the Development of Fiber Cement Components

    SciTech Connect

    Dias, C. M. R.; John, V. M.; Savastano, H. Jr.

    2008-02-15

    The FGM concept appears promising in improving the mechanical performance and reducing production costs of fiber cement building components. However, it has not yet been broadly applied to fiber cement technology. In this study we analyze the functionally graded fiber cement concept and its potential for industrial application in Hatschek machines. The conventional Hatschek process is summarized as well as the proposed modifications to allow FGM fiber cement production. The feasibility of producing functionally graded fiber cement by grading PVA fiber content was experimentally evaluated. Thermogravimetric (TG) and Scanning Electron Microscope (SEM) analysis were used to evaluate fiber distribution profiles. Four-point bending tests were applied to evaluate the mechanical performance of both conventional and functionally graded composites. The results shows that grading PVA fiber content is an effective way to produce functionally graded fiber cement, allowing the reduction of the total fiber volume without significant reduction on composite MOR. TG tests were found adequate to assess fiber content at different positions in functionally graded fiber cements.

  20. Cancer mortality in towns in the vicinity of installations for the production of cement, lime, plaster, and magnesium oxide.

    PubMed

    Garca-Prez, Javier; Lpez-Abente, Gonzalo; Castell, Adela; Gonzlez-Snchez, Mario; Fernndez-Navarro, Pablo

    2015-06-01

    Our objective was to investigate whether there might be excess cancer mortality in the vicinity of Spanish installations for the production of cement, lime, plaster, and magnesium oxide, according to different categories of industrial activity. An ecologic study was designed to examine municipal mortality due to 33 types of cancer (period 1997-2006) in Spain. Population exposure to pollution was estimated on the basis of distance from town to industrial facility. Using spatial Besag-York-Molli regression models with integrated nested Laplace approximations for Bayesian inference, we assessed the relative risk of dying from cancer in a 5-km zone around installations, analyzed the effect of category of industrial activity according to the manufactured product, and conducted individual analyses within a 50-km radius of each installation. Excess all cancer mortality (relative risk, 95% credible interval) was detected in the vicinity of these installations as a whole (1.04, 1.01-1.07 in men; 1.03, 1.00-1.06 in women), and, principally, in the vicinity of cement installations (1.05, 1.01-1.09 in men). Special mention should be made of the results for tumors of colon-rectum in both sexes (1.07, 1.01-1.14 in men; 1.10, 1.03-1.16 in women), and pleura (1.71, 1.24-2.28), peritoneum (1.62, 1.15-2.20), gallbladder (1.21, 1.02-1.42), bladder (1.11, 1.03-1.20) and stomach (1.09, 1.00-1.18) in men in the vicinity of all such installations. Our results suggest an excess risk of dying from cancer, especially in colon-rectum, in towns near these industries. PMID:25681568

  1. Simultaneous chromizing-aluminizing coating of low-alloy steels by a halide-activated, pack-cementation process

    SciTech Connect

    Geib, F.D.; Rapp, R.A. )

    1993-10-01

    The simultaneous chromizing aluminizing of low-alloy steels has achieved Kanthal-like surface compositions of 16-21Cr and 5 8wt.% AI by the use of cementation packs with a Cr Al masteralloy and an NH[sub 4]Cl activator salt. An initial preferential deposition of Al into the alloy induces the phase transformation from austenite to ferrite at the 1150[degrees]C process temperature. The low solubility of carbon in ferrite results in the rejection of solute C into the austenitic core, thereby presenting the formation of an external Cr-carbide layer, which would otherwise block aluminizing and chromizing. The deposition and rapid diffusion of Cr and Al into the external bcc ferrite layer follows. Parabolic, cyclic-oxidation kinetics for alumina growth on the coated steels in air were observed over a wide range of relatively low temperatures (637-923[degrees]C). 20 refs., 9 figs., 1 tab.

  2. Research of magnesium phosphosilicate cement

    NASA Astrophysics Data System (ADS)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product in MPSC is MgKPO4·6H2O (MKP), which has both crystalline and amorphous phases. There are many unreacted magnesia grains in the hardened MPSC paste. They act as nucleus of the hardened framework. The hydrates grow around the magnesia grains rims, fill in the voids among the magnesia grains and bond unreacted magnesia part into a solid continuum. (Abstract shortened by UMI.)

  3. A feasibility study to use coal tar contaminated soil in asphalt cement mixture production

    SciTech Connect

    Dulam, C.S.; Hoag, G.E.; Dahmani, A.; Nadim, F.

    1996-11-01

    Coal tars are the residues produced during the gasification of coal. Traditionally, coal tars were buried onsite at the power plants or left as residuals in the bottom of gas holders. Currently, there are more than 1,500 such historic sites which will undergo site assessment in the near future. The use of coal tar residuals in asphalt-based products could result in greatly reduced disposal costs, in comparison to current methods of disposal. Present disposal practice of coal tar contaminated residuals includes disposal in hazardous waste landfills or incineration. Treatment and disposal costs are reported to be as much as $1,000/ton for current coal tar contaminated residuals disposal options. This feasibility study was performed to determine the use of coal tar contaminated soil (CTCS) in bituminous materials to produce hot asphalt mix. Mixtures of varying composition of CTCS and bituminous material were produced to perform TCLP. The air emissions during the mixing process were captured and analyzed. In this study, a bench scale investigation was performed to identify and quantify the emissions from heating the CTCS at the mixer temperature. The pilot scale investigations were performed by replacing reclaimable asphalt pavement (RAP) with CTCS during the hot asphalt mix production. The investigations were performed on two types of mixtures; using CTCS as the direct additive in the first type, and using SS-1 (slow setting asphalt emulsion) stabilized CTCS as an additive in the second type.

  4. Fluid loss control in oil field cements

    SciTech Connect

    Newlove, J. C.; Kitano, K.; Portnoy, R. C.; Schulz, D. N.

    1984-11-06

    The present invention relates to materials which reduce the filtration of fluid into permeable earth formations during cementing processes in the drilling and completing of subterranean wells, particularly wells for the recovery of petroleum resources. Petroleum well cementing is the process of mixing a slurry of cement, water, and other additives and pumping it down through steel casing to critical points in the oil well annulus around the casing or in the open hole below the casing string. The primary functions of the cementing process are to restrict fluid movement between geological formations and to bond and support the casing. In addition the cement aids in protecting the casing from corrosion, preventing blowouts by quickly sealing formations, protecting the casing from shock loads in drilling deeper wells, and sealing off lost circulation or thief zones. A common problem in petroleum well cementing is the flow of liquid from the cement slurry into porous earth formations in contact with the cement. This fluid loss is undesirable since it can result in dehydration of the cement slurry, and it causes thick filter cakes of cement solids which can plug the well bore. The fluid lost can damage sensitive formations. Cement fluid loss is particularly a problem in the process known as squeeze cementing. There is a requirement, therefore, for materials which, when added to the cement formulation, reduce the loss of fluid from the slurry to porous formations.

  5. Cementing apparatus

    SciTech Connect

    Coone, M.G.; Cole, F.

    1993-08-10

    For use in cementing a casing string within a well bore, an assembly is described comprising: a float collar including an outer body connectable as part of the casing string and an inner body having a bore there through having upper and lower ends and a valve member in the bore to permit flow downwardly and prevent flow upwardly there through, a cement plug including a body having a bore there through and upper and lower ends with a frangible diaphragm there across and lips there about flexibly engagable with the casing string to permit the plug to be prepared downwardly onto the float collar, the upper end of the bore of the float collar having threads thereon and the lower end of the body of the cement plug having threads there about for limited make-up with the threads in the bore of the float collar in response to rotation of the cement plug in one direction, and a wiper plug comprising a body having lips there about flexibly engagable with the casing string to permit the wiper plug to be pumped downwardly onto the cement plug, the upper end of the bore of the cement plug having threads thereon and the lower end of the bore of the body of the wiper plug having threads there about for limited make-up with the threads in the bore of the cement plug in response to rotation of the wiper plug in said one direction, and the inner body of the float collar and the bodies of the cement and wiper plugs being of a drillable material.

  6. Squeeze cementing

    SciTech Connect

    Ewert, D.P.; Kundert, D.P.; Dahl, J.A.; Dalrymple, E.D.; Gerke, R.R.

    1992-06-16

    This patent describes a method for terminating the flow of fluid from a portion of a subterranean formation into a wellbore. It comprises: placing within the wellbore adjacent the portion a volume of a slurry of hydraulic cement, permitting the volume to penetrate into the portion; and maintaining the slurry in the portion for a time sufficient to enable the slurry to form a rigid mass of cement in the portion.

  7. Process optimization for biodiesel production.

    PubMed

    Singh, Veena; Solanki, Kusum; Gupta, Munishwar N

    2008-01-01

    Biodiesel is an alkyl ester of long chain fatty acids and is considered to leave smaller footprint on the environment. It is produced by transesterification of a fat/oil with a short chain primary alcohol like methanol or ethanol. The three routes to its preparation are: alkali catalyzed, acid catalyzed and lipase-catalyzed transesterification. This review summarizes the key patents filed over the last few decades. The chemistry used in these patents is one of the three routes mentioned above. In few patents, heterogeneous catalysts have been used for catalyzing the transesterification process. The innovations mostly concern fine-tuning of the reaction conditions, plant design to improve logistics and use of glycerol produced as a by-product during biodiesel production. There is a concern that biofuels like biodiesel cut into resources like land meant for food crop production. Life cycle studies also create doubt about there being energy efficient fuels. Judicious choices that would differ with different regions are recommended. For the next few decades till better alternatives like hydrogen become viable, biodiesel would continue to be an important "alternative fuel". PMID:19075861

  8. The proposed fixation of sludge in cement at the Feed Materials Production Center

    SciTech Connect

    Gimpel, R.F.

    1990-12-01

    The Feed Materials Production Center (FMPC), located near Cincinnati, Ohio, is a government-owned facility. Westinghouse Materials Company of Ohio (WMCO) is the prime contractor to the United States Department of Energy (DOE) at the FMPC. DOE has entered into a Consent Agreement with the United States Environmental Protection Agency (US EPA) to remediate the FMPC site. A project known as the Environmental Remedial Action (ERA) Project was created to accomplish the task of remediating the site. The majority of the estimated $2-billion ERA Project was broken into five smaller manageable subtasks called operable units.'' Each operable unit is handled as a project with its own project manager/engineer. Due to the project's complexity and stringent completion dates, DOE and WMCO have devised a project management philosophy to ensure the successful completion of the ERA Project. This paper will discuss the ERA project and the development needs to accomplish this project. In particular, development of processes for the treatment of waste sludges for Operable Units 1 and 4 will be discussed. Operable Units 2 sludges will be treated in a similar fashion to Operable Unit 1 if it is determined these sludges need treatment. 4 refs., 5 figs., 9 tabs.

  9. Climate change: The impact of the third conference of the parties at Kyoto on the U.S. Portland cement industry

    SciTech Connect

    Cahn, D.; Nisbet, M.; O`Hare, A.

    1998-12-31

    The paper provides, as background, a brief review of the structure of the US cement industry. It outlines the growth trends of the industry over the last 20 years. It describes the sources and significance of cement imports in the US market, and the importance of exports to Canadian cement producers. The sources of CO{sub 2}, the primary greenhouse gas emitted in the cement manufacturing process, are explained and the impact of improved energy efficiency and fuel switching on CO{sub 2} emissions per ton of product are discussed. The aspects of the Kyoto Protocol relevant to the US cement industry are analyzed as are the types of impacts they can be expected to have on: cement trade, domestic cement production, long term growth of the US cement industry, and US cement industry CO{sub 2} emissions. The paper projects the US cement industry CO{sub 2} emissions to 2010, taking into account anticipated improvements in energy efficiency. It discusses manufacturing process and changes that could be made to reduce CO{sub 2} emissions. The paper also covers the types of product modifications that might be made to reduce the embodied CO{sub 2} content. Where possible the potential reductions in CO{sub 2} emissions from process and product changes are quantified.

  10. Development of nanosilica bonded monetite cement from egg shells.

    PubMed

    Zhou, Huan; Luchini, Timothy J F; Boroujeni, Nariman Mansouri; Agarwal, Anand K; Goel, Vijay K; Bhaduri, Sarit B

    2015-05-01

    This work represents further effort from our group in developing monetite based calcium phosphate cements (CPC). These cements start with a calcium phosphate powder (MW-CPC) that is manufactured using microwave irradiation. Due to the robustness of the cement production process, we report that the starting materials can be derived from egg shells, a waste product from the poultry industry. The CPC were prepared with MW-CPC and aqueous setting solution. Results showed that the CPC hardened after mixing powdered cement with water for about 12.5±1 min. The compressive strength after 24h of incubation was approximately 8.45±1.29 MPa. In addition, adding colloidal nanosilica to CPC can accelerate the cement hardening (10±1 min) process by about 2.5 min and improve compressive strength (20.16±4.39 MPa), which is more than double the original strength. The interaction between nanosilica and CPC was monitored using an environmental scanning electron microscope (ESEM). While hardening, nanosilica can bond to the CPC crystal network for stabilization. The physical and biological studies performed on both cements suggest that they can potentially be used in orthopedics. PMID:25746244

  11. Chemical production processes and systems

    SciTech Connect

    Holladay, Johnathan E; Muzatko, Danielle S; White, James F; Zacher, Alan H

    2015-04-21

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  12. Chemical production processes and systems

    SciTech Connect

    Holladay, Johnathan E.; Muzatko, Danielle S.; White, James F.; Zacher, Alan H.

    2014-06-17

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  13. Influence of ferrite phase in alite-calcium sulfoaluminate cements

    NASA Astrophysics Data System (ADS)

    Duvallet, Tristana Yvonne Francoise

    Since the energy crisis in 1970's, research on low energy cements with low CO2- emissions has been increasing. Numerous solutions have been investigated, and the goal of this original research is to create a viable hybrid cement with the components of both Ordinary Portland cement (OPC) and calcium sulfoaluminate cement (CSAC), by forming a material that contains both alite and calcium sulfoaluminate clinker phases. Furthermore, this research focuses on keeping the cost of this material reasonable by reducing aluminum requirements through its substitution with iron. The aim of this work would produce a cement that can use large amounts of red mud, which is a plentiful waste material, in place of bauxite known as an expensive raw material. Modified Bogue equations were established and tested to formulate this novel cement with different amounts of ferrite, from 5% to 45% by weight. This was followed by the production of cement from reagent chemicals, and from industrial by-products as feedstocks (fly ash, red mud and slag). Hydration processes, as well as the mechanical properties, of these clinker compositions were studied, along with the addition of gypsum and the impact of a ferric iron complexing additive triisopropanolamine (TIPA). To summarize this research, the influence of the addition of 5-45% by weight of ferrite phase, was examined with the goal of introducing as much red mud as possible in the process without negatively attenuate the cement properties. Based on this PhD dissertation, the production of high-iron alite-calcium sulfoaluminateferrite cements was proven possible from the two sources of raw materials. The hydration processes and the mechanical properties seemed negatively affected by the addition of ferrite, as this phase was not hydrated entirely, even after 6 months of curing. The usage of TIPA counteracted this decline in strength by improving the ferrite hydration and increasing the optimum amount of gypsum required in each composition. The mechanical data were equivalent to OPC strengths for some compositions with 25% ferrite. This preliminary work constitutes the first research phase of this novel cement and requires additional research for its improvement. Topics for additional research are identified in this dissertation. KEYWORDS: alite, calcium sulfoaluminate, ferrite, low-energy cement, triisopropanolamine.

  14. Effect of resin cement, aging process and root level on the bond strength of the resin-fiber posts

    NASA Astrophysics Data System (ADS)

    Almuhim, Khalid Salman

    Background. Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods. Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning electron microscope (SEM) examination of the surface morphology in order to obtain SEM images of the failure patterns at 29--70x magnifications. Statistical analysis: Nested general linear and generalized linear model was created to look for statistical significance. Level of significance was set at P < 0.05. Results. No significant differences were found on the bond strength between the two types of resin cement systems (total etch and self-etch). Regarding the thermocycling effect, the bond strengths of the group of 40,000 cycles was significantly lower than the 20,000 cycle group. In addition, the bond strengths of the specimens collected from the coronal third of the root were significantly lower than the specimens from the apical third. A Fisher's Exact test was applied to evaluate the failure mode differences, and showed statistically significant differences between the groups. Conclusions . The bond strength to the root canal dentin did not vary with the type of resin cement systems (total-etch vs self-etch). The microtensile bond strength values of FRC posts were significantly affected by increasing the thermocycling, and were significantly different among the different longitudinal levels of the root canal.

  15. Synthesis of aluminum-rich coatings on new high-temperature cast austenitic steel CF8C-Plus by a pack cementation process

    NASA Astrophysics Data System (ADS)

    Hall, Alex Keith

    2011-12-01

    In this research, a pack cementation process is developed for coating the newly developed cast austenitic steel CF8C-Plus. The developed coating process is capable of producing pack particle free coatings on large fatigue test specimens in a horizontal laboratory tube furnace as well as smaller oxidation and creep test samples. Several methods for the production of the pack powder free Al-rich coating are presented and evaluated for samples of both sizes. The developed coating is intended to compete with coatings of a similar quality produced with chemical vapor deposition and slurry coating methods. Additionally, because CF8C-Plus has only recently become available there is currently no available data on the effect of the fabrication of an Al-rich coating on the substrates properties. This research used advanced characterization methods to evaluate the coating surface and cross-sectional features. These methods include scanning electron microscopy, X-ray diffraction, electron probe microanalysis and energy dispersive spectroscopy analysis. This is the first time that this information has been made available to the scientific community. Also, the oxidation performance of the coating will be tested and compared to other coatings developed with CVD and slurry coating methods and the preliminary results of the effect of the coating on the alloys fatigue performance will be presented.

  16. Characterization of spatial impact of particles emitted from a cement material production facility on outdoor particle deposition in the surrounding community.

    PubMed

    Yu, Chang Ho; Fan, Zhihua; McCandlish, Elizabeth; Stern, Alan H; Lioy, Paul J

    2011-10-01

    The objective of this study was to estimate the contribution of a facility that processes steel production slag into raw material for cement production to local outdoor particle deposition in Camden, NJ. A dry deposition sampler that can house four 37-mm quartz fiber filters was developed and used for the collection of atmospheric particle deposits. Two rounds of particle collection (3-4 weeks each) were conducted in 8-11 locations 200-800 m downwind of the facility. Background samples were concurrently collected in a remote area located -2 km upwind from the facility. In addition, duplicate surface wipe samples were collected side-by-side from each of the 13 locations within the same sampling area during the first deposition sampling period. One composite source material sample was also collected from a pile stored in the facility. Both the bulk of the source material and the < 38 microm fraction subsample were analyzed to obtain the elemental source profile. The particle deposition flux in the study area was higher (24-83 mg/m2 x day) than at the background sites (13-17 mg/m2day). The concentration of Ca, a major element in the cement source production material, was found to exponentially decrease with increasing downwind distance from the facility (P < 0.05). The ratio of Ca/Al, an indicator of Ca enrichment due to anthropogenic sources in a given sample, showed a similar trend. These observations suggest a significant contribution of the facility to the local particle deposition. The contribution of the facility to outdoor deposited particle mass was further estimated by three independent models using the measurements obtained from this study. The estimated contributions to particle deposition in the study area were 1.8-7.4% from the regression analysis of the Ca concentration in particle deposition samples against the distance from the facility, 0-11% from the U.S. Environmental Protection Agency (EPA) Chemical Mass Balance (CMB) source-receptor model, and 7.6-13% from the EPA Industrial Source Complex Short Term (ISCST3) dispersion model using the particle-size-adjusted permit-based emissions estimates. PMID:22070034

  17. Characterization of Spatial Impact of Particles Emitted from a Cement Material Production Facility on Outdoor Particle Deposition in the Surrounding Community

    PubMed Central

    Yu, Chang Ho; Fan, Zhihua (Tina); McCandlish, Elizabeth; Stern, Alan H.; Lioy, Paul J.

    2014-01-01

    The objective of this study was to estimate the contribution of a facility that processes steel production slag into raw material for cement production to local outdoor particle deposition in Camden, NJ. A dry deposition sampler that can house four 37-mm quartz fiber filters was developed and used for the collection of atmospheric particle deposits. Two rounds of particle collection (34 weeks each) were conducted in 811 locations 200800 m downwind of the facility. Background samples were concurrently collected in a remote area located ~2 km upwind from the facility. In addition, duplicate surface wipe samples were collected side-by-side from each of the 13 locations within the same sampling area during the first deposition sampling period. One composite source material sample was also collected from a pile stored in the facility. Both the bulk of the source material and the <38 ?m fraction subsample were analyzed to obtain the elemental source profile. The particle deposition flux in the study area was higher (2483 mg/m2 day) than at the background sites (1317 mg/m2day). The concentration of Ca, a major element in the cement source production material, was found to exponentially decrease with increasing downwind distance from the facility (P < 0.05). The ratio of Ca/Al, an indicator of Ca enrichment due to anthropogenic sources in a given sample, showed a similar trend. These observations suggest a significant contribution of the facility to the local particle deposition. The contribution of the facility to outdoor deposited particle mass was further estimated by three independent models using the measurements obtained from this study. The estimated contributions to particle deposition in the study area were 1.87.4% from the regression analysis of the Ca concentration in particle deposition samples against the distance from the facility, 011% from the U.S. Environmental Protection Agency (EPA) Chemical Mass Balance (CMB) source-receptor model, and 7.613% from the EPA Industrial Source Complex Short Term (ISCST3) dispersion model using the particle-size-adjusted permit-based emissions estimates. PMID:22070034

  18. Cellular automata modelling of the cementation process of the Turin (Italy) subsoil conglomerate (``ceppo''),based on a three-dimensional geological model of the city subsoil.

    NASA Astrophysics Data System (ADS)

    Bello, S.; de Rienzo, F.; Nardi, G.

    2003-04-01

    The Turin (Italy) subsoil is mainly made up by alluvial gravels and sands (Pleistocene), characterised by high cementation degree variability, covered by a thin thickness of loess. These alluvial sediments, of about 40 m deep, overlay lacustrine clays (Villafranchiano), locally heteropic with marine sandstones (Pliocene). The reconstruction of the areal distribution of cementation phenomena of the Turin urban subsoil is of fundamental importance within the context of planning and carrying out works in the city subsoil, as well as for preliminary evaluating the stability of such underground works. Moreover, analyses of spatial distribution of soil cementation could be usefully applied for estimating the propagation of waste-polluted fluids, and for reducing either the natural or human-induced risk, related to the overworking of urban area subsoils. The development of mathematical models commonly needs to deal with several interacting physical and chemical phenomena. A deterministic Cellular Automata (CA) model for the evaluation of cementation processes in the conglomerates of the Turin urban subsoil has recently been developed, by using a three-dimensional geological model of the city subsoil based on boreholes data. The model is able to simulate the spatial distribution of the cementation process in the studied area: it has been derived from two pre-existing CA models, i.e. SCAVATU and CABOTO. Geological, mineralogical-petrographic and sedimentological studies of the soil cementation, and a chemical-physical study of the carbonatic equilibria, have first been carried out. These studies pointed out the presence of meniscus cements (which suggest a meteoric diagenesis) and gave fundamental cues for the development of base hypothesis on the genesis of cementation in the considered area. A macroscopic Cellular Automata model has accordingly been developed, in order to simulate the principal phenomena which take place during the cementation process. The model has a ''layered structure'', composed of the following three layers: 1) the first quantitatively describes pluviometric events in the Turin area. The global amount of rain is subdivided into ''run-off'' and ''infiltration'', by using the c.i.p. value. This layer concerns only the space region in which the run-off occurs: such cells have been classified as ''A'' type. 2) the second layer describes the fluid flow of ''water'' through the soil (i.e. loess and conglomerate). It concerns the space region of the Turin subsoil: such cells have been classified as ''B'' type. 3) the third layer describes the chemical-physical phenomena of ''solute transport'', ''diffusion and chemical reactions of dissolution'', and ''precipitation of calcium carbonate''. Inside the above mentioned cells, the chemical-physical phenomena are allowed to occur. Owing to their high complexity, the global phenomena under consideration have been decomposed into ''elementary'' processes (run-off, infiltration and chemical-physical reactions) and properly translated into CA local rules. The model, opportunely implemented in a parallel computing environment, allows to simulate the process of cementation of the Turin urban subsoil: as mentioned above, it could be therefore usefully applied for mitigating natural and man-induced hazards in the study area.

  19. Passamaquoddy Technology Recovery Scrubber{trademark} at the Dragon Products, Inc. Cement Plant located in Thomaston, Maine. 1990 Annual technical report

    SciTech Connect

    Not Available

    1990-12-31

    The background and process of the Passamaquoddy Technology Recovery Scrubber{trademark} are described. The Scrubber was developed for Dragon Cement Plant in Thomaston, Maine and facilitates a number of process improvements. The exhaust gas is scrubbed of SO{sub 2} with better than 90% efficiency. The kiln dust is cleaned of alkalines and so can be returned to kiln feed instead of dumped to landfill. Potassium sulfate in commercial quantity and purity can be recovered. Distilled water is recovered which also has commercial potential. Thus, various benefits are accrued and no waste streams remain for disposal. The process is applicable to both wet and dry process cement kilns and appears to have potential in any industry which generates acidic gaseous exhausts and/or basic solid or liquid wastes.

  20. Utilization of municipal solid waste incineration (MSWI) fly ash in blended cement Part 1: Processing and characterization of MSWI fly ash.

    PubMed

    Aubert, J E; Husson, B; Sarramone, N

    2006-08-25

    This paper is the first of a series of two articles dealing with the processes applied to MSWI fly ash with a view to reusing it safely in cement-based materials. Part 1 presents two stabilization processes and Part 2 deals with the use of the two treated fly ashes (TFA) in mortars. Two types of binder were used: an Ordinary Portland Cement (OPC) containing more than 95% clinker (CEM I 52.5R) and a binary blend cement composed of 70% ground granulated blast furnace slag and 30% clinker (CEM III-B 42.5N). In this first part, two stabilization processes are presented: the conventional process, called "A", based on the washing, phosphation and calcination of the ash, and a modified process, called "B", intended to eliminate metallic aluminum and sulfate contained in the ash. The physical, chemical and mineralogical characteristics of the two TFA were comparable. The main differences observed were those expected, i.e. TFA-B was free of metallic aluminum and sulfate. The mineralogical characterization of the two TFAs highlighted the presence of large amounts of a calcium aluminosilicate phase taking two forms, a crystalline form (gehlenite) and an amorphous form. Hydration studies on pastes containing mixed TFA and calcium hydroxide showed that this phase reacted with calcium hydroxide to form calcium aluminate hydrates. This formation of hydrates was accompanied by a hardening of the pastes. These results are very encouraging for the reuse of such TFA in cement-based materials because they can be considered as pozzolanic additions and could advantageously replace a part of the cement in cement-based materials. Finally, leaching tests were carried out to evaluate the environmental impact of the two TFAs. The elements which were less efficiently stabilized by process A were zinc, cadmium and antimony but, when the results of the leaching tests were compared with the thresholds of the European landfill directive, TFA-A could nevertheless be accepted at landfills for non-hazardous waste. The modifications of the process led to a significant reduction in the stabilization of chromium, selenium and antimony. PMID:16442718

  1. Thermal Shock-resistant Cement

    SciTech Connect

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved cement, causing its volume to expand.

  2. Cement advanced furnace component and system optimization. Volume 1. Final report, August 1989-April 1993

    SciTech Connect

    Keane, K.; Chatwani, A.; Litka, A.

    1994-10-01

    Research and development of the Cement Advanced Furnace (CAF) vertical shaft kiln has been performed under the sponsorship of the Gas Research Institute and Southern California Gas Co. by Textron Defense Systems and Fuller Co. The CAF represents a low cost, energy efficient, very low polluting alternative to traditional rotary kilns for the production of Portland and specialty cements. The testing program has resulted in the development of an integrated shaft furnace that has produced clinker in a pilot plant at rates up to 2200 lb/hr. The unit can be scaled to commercial sizes with the aid of a mathematical model of the equipment and process developed as part of this effort. Cement produced in this program is as strong as, but easier to grind than, cement produced in conventional rotary kilns. Polluting emissions from the CAF are lower than from conventional cement processing equipment by virtue of the use of natural gas as fuel and a low combustion temperature.

  3. Durability of pulp fiber-cement composites

    NASA Astrophysics Data System (ADS)

    Mohr, Benjamin J.

    Wood pulp fibers are a unique reinforcing material as they are non-hazardous, renewable, and readily available at relatively low cost compared to other commercially available fibers. Today, pulp fiber-cement composites can be found in products such as extruded non-pressure pipes and non-structural building materials, mainly thin-sheet products. Although natural fibers have been used historically to reinforce various building materials, little scientific effort has been devoted to the examination of natural fibers to reinforce engineering materials until recently. The need for this type of fundamental research has been emphasized by widespread awareness of moisture-related failures of some engineered materials; these failures have led to the filing of national- and state-level class action lawsuits against several manufacturers. Thus, if pulp fiber-cement composites are to be used for exterior structural applications, the effects of cyclical wet/dry (rain/heat) exposure on performance must be known. Pulp fiber-cement composites have been tested in flexure to examine the progression of strength and toughness degradation. Based on scanning electron microscopy (SEM), environmental scanning electron microscopy (ESEM), energy dispersive spectroscopy (EDS), a three-part model describing the mechanisms of progressive degradation has been proposed: (1) initial fiber-cement/fiber interlayer debonding, (2) reprecipitation of crystalline and amorphous ettringite within the void space at the former fiber-cement interface, and (3) fiber embrittlement due to reprecipitation of calcium hydroxide filling the spaces within the fiber cell wall structure. Finally, as a means to mitigate kraft pulp fiber-cement composite degradation, the effects of partial portland cement replacement with various supplementary cementitious materials (SCMs) has been investigated for their effect on mitigating kraft pulp fiber-cement composite mechanical property degradation (i.e., strength and toughness losses) during wet/dry cycling. SCMs have been found to be effective in mitigating composite degradation through several processes, including a reduction in the calcium hydroxide content, stabilization of monosulfate by maintaining pore solution pH, and a decrease in ettringite reprecipitation accomplished by increased binding of aluminum in calcium aluminate phases and calcium in the calcium silicate hydrate (C-S-H) phase.

  4. Wood Technology: Techniques, Processes, and Products

    ERIC Educational Resources Information Center

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and…

  5. Wood Technology: Techniques, Processes, and Products

    ERIC Educational Resources Information Center

    Oatman, Olan

    1975-01-01

    Seven areas of wood technology illustrates applicable techniques, processes, and products for an industrial arts woodworking curriculum. They are: wood lamination; PEG (polyethylene glycol) diffusion processes; wood flour and/or particle molding; production product of industry; WPC (wood-plastic-composition) process; residential construction; and

  6. Sulfoaluminate-belite cement from low-calcium fly ash and sulfur-rich and other industrial by-products

    SciTech Connect

    Arjunan, P.; Silsbee, M.R.; Roy, D.M.

    1999-08-01

    The study describes the preparation and characterization of an environmentally friendly cement with performance characteristics similar to those of Portland cement, from a lime kiln bag house dust, a low-calcium fly ash, and a scrubber sludge. Promising preliminary results show the formation of relatively low-temperature phases calcium sulfoaluminate (4CaO{center{underscore}dot}3Al{sub 2}O{sub 3}{center{underscore}dot}SO{sub 3}) and dicalcium silicate (2CaO{center{underscore}dot}SiO{sub 2}) at {approximately} 1,250 C if nodulized raw means used for clinker preparation and at 1,175 C if powdered raw meal is used as compared to the {approximately} 1,500 C sintering temperature required for Portland cement. Phases of the developed cements were predicted using modified Bogue calculations. Isothermal calorimetric measurements indicate the hydration properties of the cements are comparable to ordinary Portland cement. Mechanical properties and microstructural evaluations also were carried out.

  7. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    NASA Astrophysics Data System (ADS)

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate-belite cement that contained medium C4A3 S¯ and C2S contents showed good dimensional stability, sulfate resistance, and compressive strength development and was considered the optimum phase composition for calcium sulfoaluminate-belite cement in terms of comparable performance characteristics to portland cement. Furthermore, two calcium sulfoaluminate-belite cement clinkers were successfully synthesized from natural and waste materials such as limestone, bauxite, flue gas desulfurization sludge, Class C fly ash, and fluidized bed ash proportioned to the optimum calcium sulfoaluminate-belite cement synthesized from reagent-grade chemicals. Waste materials composed 30% and 41% of the raw ingredients. The two calcium sulfoaluminate-belite cements synthesized from natural and waste materials showed good dimensional stability, sulfate resistance, and compressive strength development, comparable to commercial portland cement.

  8. Nanostructured TaxC interlayer synthesized via double glow plasma surface alloying process for diamond deposition on cemented carbide

    NASA Astrophysics Data System (ADS)

    Rong, Wolong; Hei, Hongjun; Zhong, Qiang; Shen, Yanyan; Liu, Xiaoping; Wang, Xin; Zhou, Bing; He, Zhiyong; Yu, Shengwang

    2015-12-01

    The aim in this work was to improve the adhesion of diamond coating with pre-deposition of a TaxC interlayer on cemented carbide (WC-Co) substrate by double glow plasma surface alloying technique. The following deposition of diamond coating on the interlayer was performed in a microwave plasma chemical vapor deposition (MPCVD) reactor. TaxC interlayer with an inner diffusion layer and an outer deposition layer was composed of Ta2C and TaC nanocrystalline, and it exhibited a special compact surface morphology formed of flower-shaped pits. As the gradual element distributions existed in the diffusion layer, the interlayer displayed a superior adherence to the substrate with significantly enhanced surface microhardness to the original substrate. After CVD process, the preferred orientation of TaC changed from (2 2 2) to (2 0 0) plane, and a uniform and tense diamond coating with adhesion referred to class HF 2 at least (Verein Deutscher Ingenieure 3198 norm) was obtained on the interlayered substrate. It indicated that the diffusion of Co was effectively inhibited by the formation of TaxC diffusion-deposition interlayer. The TaxC interlayer is most likely to improve the performance of diamond coatings used in cutting tools.

  9. Modelling of hydrogen production from pore water radiolysis in cemented intermediate level waste

    NASA Astrophysics Data System (ADS)

    Foct, F.; Di Giandomenico, M.-V.; Bouniol, P.

    2013-07-01

    In France, some of the intermediate and low level wastes are embedded in hydraulic binder and put into concrete canisters. They contain ? and ? emitters which cause an irradiation of water present in the pores of the hydraulic binder. This is responsible for a dihydrogen (H2) production due to radiolysis. EDF R&D and CEA have collaborated since many years in order to understand this phenomenon and develop a model called DO-RE-MI which can predict such a production of dihydrogen in concrete waste packages. A parametric study, using the developed model, was implemented in order to determine the effects of each parameter on H2 production. The main results are presented in this paper.

  10. Effect of Eu-citrate complex composition on its cementation

    SciTech Connect

    Lebedev, V.M.; Kornilov, A.S.; Yadovin, A.A.

    1995-03-01

    The dependence of Eu cementation by sodium amalgam in a semicountercurrent regime from citrate solutions on the Eu complex composition is studied. The purity of the {sup 153}Gd product from radioactive Eu can be increased during cementation by introducing correcting solutions of citric acid and stable Eu. The selected conditions are verified by processing irradiated targets. The content of radioactive Eu in the {sup 153}Gd product is reduced from 0.01 to 0.0005% with respect to {gamma}-activity.

  11. Process for impregnating a concrete or cement body with a polymeric material

    DOEpatents

    Mattus, Alfred J. (Kingston, TN); Spence, Roger D. (Clinton, TN)

    1989-01-01

    A process for impregnating cementitious solids with polymeric materials by blending polymeric materials in a grout, allowing the grout to cure, and contacting the resulting solidified grout containing the polymeric materials with an organic mixture containing a monomer, a cross-linking agent and a catalyst. The mixture dissolves the polymerized particles and forms a channel for distributing the monomer throughout the network formed by the polymeric particles. The organic components are then cured to form a substantially water-impermeable mass.

  12. Process for impregnating a concrete or cement body with a polymeric material

    DOEpatents

    Mattus, A.J.; Spence, R.D.

    1988-05-04

    A process for impregnating cementitious solids with polymeric materials by blending polymeric materials in a grout, allowing the grout to cure, and contacting the resulting solidified grout containing the polymeric materials with an organic mixture containing a monomer, a cross-linking agent and a catalyst. The mixture dissolves the polymerized particles and forms a channel for distributing the monomer throughout the network formed by the polymeric particles. The organic components are then cured to form a substantially water-impermeable mass.

  13. A Thermoelectric Waste-Heat-Recovery System for Portland Cement Rotary Kilns

    NASA Astrophysics Data System (ADS)

    Luo, Qi; Li, Peng; Cai, Lanlan; Zhou, Pingwang; Tang, Di; Zhai, Pengcheng; Zhang, Qingjie

    2015-06-01

    Portland cement is produced by one of the most energy-intensive industrial processes. Energy consumption in the manufacture of Portland cement is approximately 110-120 kWh ton-1. The cement rotary kiln is the crucial equipment used for cement production. Approximately 10-15% of the energy consumed in production of the cement clinker is directly dissipated into the atmosphere through the external surface of the rotary kiln. Innovative technology for energy conservation is urgently needed by the cement industry. In this paper we propose a novel thermoelectric waste-heat-recovery system to reduce heat losses from cement rotary kilns. This system is configured as an array of thermoelectric generation units arranged longitudinally on a secondary shell coaxial with the rotary kiln. A mathematical model was developed for estimation of the performance of waste heat recovery. Discussions mainly focus on electricity generation and energy saving, taking a Φ4.8 × 72 m cement rotary kiln as an example. Results show that the Bi2Te3-PbTe hybrid thermoelectric waste-heat-recovery system can generate approximately 211 kW electrical power while saving 3283 kW energy. Compared with the kiln without the thermoelectric recovery system, the kiln with the system can recover more than 32.85% of the energy that used to be lost as waste heat through the kiln surface.

  14. Rigless multizone recompletion using a cement packer placed with coiled tubing: A case history

    SciTech Connect

    Nowak, T.W.; Patout, T.S.

    1997-12-01

    Cement packers have been used for some time when reserve estimates have not justified the cost of major rig remedial work. They typically provide a means of zonal isolation of the last reserves in an existing wellbore. The success of these operations has historically been low. This is predominantly because of poor cement bonding in the annulus between the tubing and production casing. Because of the minimal amount of equipment on location and lack of upfront design work involved, most cement packers are doomed to failure before they are even placed. Cement packers have been placed using a large number of methods. In the Ship Shoal 181 field, Well B-4 would not economically justify a major rig workover, even though there were several uphole gas sands capable of producing in this well. With proper upfront planning and design, it would be economical; however, all these reserves could be produced in a through-tubing process using a cement packer. This case history presents a refined look at existing technology involving placement of a cement packer and reviews problems common to cement-packer completions, including a case history. Solutions are also discussed for successfully completing and recovering reserves from not one but several remaining gas intervals. This paper reviews the design considerations and precautions, along with the production results and economics, for placing what is believed to be the largest cement packer placed through coiled tubing.

  15. Field pilot study on emissions, formations and distributions of PCDD/Fs from cement kiln co-processing fly ash from municipal solid waste incinerations.

    PubMed

    Liu, Guorui; Zhan, Jiayu; Zheng, Minghui; Li, Li; Li, Chunping; Jiang, Xiaoxu; Wang, Mei; Zhao, Yuyang; Jin, Rong

    2015-12-15

    A pilot study was performed to evaluate formation, distribution and emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from cement kilns that co-process fly ash from municipal solid waste incineration (MSWI). Stack gas and particulate samples from multiple stages in the process were collected and analyzed for PCDD/Fs. Stack emissions of PCDD/Fs were below the European Union limit for cement kilns (0.1ngTEQm(-3)). PCDD/F concentrations in particulates from the cyclone preheater outlet, suspension preheater boiler, humidifier tower, and back-end bag filter were much higher than in other samples, which suggests that these areas are the major sites of PCDD/F formation. Comparison of PCDD/F homolog and congener profiles from different stages suggested that tetra- and penta-chlorinated furans were mainly formed during cement kiln co-processing of MSWI fly ash. Three lower chlorinated furan congeners, including 2,3,7,8-tetrachlorodibenzofuran, 1,2,3,7,8-pentachlorodibenzo-p-dioxin and 2,3,4,7,8-pentachlorodibenzofuran, were identified as dominant contributors to the toxic equivalents (TEQ) of the PCDD/Fs. The concentration of PCDD/Fs in particulates was correlated with chloride content, which is consistent with its positive effect on PCDD/F formation. This could be mitigated by pretreating the feedstock to remove chloride and metals. Mass balance indicated that cement kilns eliminated about 94% of the PCDD/F TEQ input from the feedstock. PMID:26241773

  16. Influence of Thermal Treatment Conditions on the Properties of Dental Silicate Cements.

    PubMed

    Voicu, Georgeta; Popa, Alexandru Mihai; Badanoiu, Alina Ioana; Iordache, Florin

    2016-01-01

    In this study the sol-gel process was used to synthesize a precursor mixture for the preparation of silicate cement, also called mineral trioxide aggregate (MTA) cement. This mixture was thermally treated under two different conditions (1400 °C/2 h and 1450 °C/3 h) followed by rapid cooling in air. The resulted material (clinker) was ground for one hour in a laboratory planetary mill (v = 150 rot/min), in order to obtain the MTA cements. The setting time and mechanical properties, in vitro induction of apatite formation by soaking in simulated body fluid (SBF) and cytocompatibility of the MTA cements were assessed in this study. The hardening processes, nature of the reaction products and the microstructural characteristics were also investigated. The anhydrous and hydrated cements were characterized by different techniques e.g., X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and thermal analysis (DTA-DTG-TG). The setting time of the MTA cement obtained by thermal treatment at 1400 °C/2 h (MTA1) was 55 min and 15 min for the MTA cement obtained at 1450 °C/3 h (MTA2). The compressive strength values were 18.5 MPa (MTA1) and 22.9 MPa (MTA2). Both MTA cements showed good bioactivity (assessed by an in vitro test), good cytocompatibility and stimulatory effect on the proliferation of cells. PMID:26901185

  17. Effect of sepiolite on the flocculation of suspensions of fibre-reinforced cement

    SciTech Connect

    Jarabo, Rocio; Fuente, Elena; Moral, Ana; Blanco, Angeles; Negro, Carlos

    2010-10-15

    Sepiolite is used to increase thixotropy of cement slurries for easier processing, to prevent sagging and to provide a better final quality in the manufacture of fibre-reinforced cement products. However, the effect of sepiolite on flocculation and its interactions with the components of fibre cement are yet unknown. The aim of this research is to study the effects of sepiolite on the flocculation of different fibre-reinforced cement slurries induced by anionic polyacrylamides (A-PAMs). Flocculation and floc properties were studied by monitoring the chord size distribution in real time employing a focused beam reflectance measurement (FBRM) probe. The results show that sepiolite increases floc size and floc stability in fibre-cement suspensions. Sepiolite competes with fibres and clay for A-PAMs adsorption and its interaction with A-PAM improves flocculation of mineral particles.

  18. Meat Products, Hydrodynamic Pressure Processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The hydrodynamic pressure process (HDP) has been shown to be very effective at improving meat tenderness in a variety of meat cuts. When compared to conventional aging for tenderization, HDP was more effective. The HDP process may offer the meat industry a new alternative for tenderizing meat in add...

  19. Shotcrete -- Understanding of the hydration process of mixes containing CAC and Portland cement and proposal for a simple rheological characterization

    SciTech Connect

    Bayoux, J.P.; Testud, M.; Guinot, D.; Willocq, J.; Capmas, A.

    1995-12-31

    In order to better understand the performances of CAC-slag cement and CAC--PC cement the hydration study of these mixes was undertaken. The hydrates which are responsible for the early stiffening/strengthening are identical in both mixes; it is only the time of appearance and amount which varies. Ettringite always forms first followed by the precipitation of C{sub 4}AH{sub 13}. They will both form faster then the temperature rises. As a complement, a simple laboratory equipment is proposed to characterize the stiffening behavior of the mixes straight after gauging.

  20. FORMATION OF A DETACHED PLUME FROM A CEMENT PLANT

    EPA Science Inventory

    A coordinated study of process, source emissions, and plume sampling was conducted at a coal-fired cement production plant. Both source and plume sampling consisted of particle and gas measurement and characterization. Particulate sampling of both the source and plume addressed p...

  1. Consolidated processes for product recovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, fermentation industries are structured on individual unit operations for production of biofuels such as ethanol, butanol, and 2,3-butanediol which result in increased capital and operational costs. Such increased costs result in low profitability and increased consumer price. With the d...

  2. Cement manufacture and the environment - Part I: Chemistry and technology

    USGS Publications Warehouse

    Van Oss, H. G.; Padovani, A.C.

    2002-01-01

    Hydraulic (chiefly portland) cement is the binding agent in concrete and mortar and thus a key component of a country's construction sector. Concrete is arguably the most abundant of all manufactured solid materials. Portland cement is made primarily from finely ground clinker, which itself is composed dominantly of hydraulically active calcium silicate minerals formed through high-temperature burning of limestone and other materials in a kiln. This process requires approximately 1.7 tons of raw materials perton of clinker produced and yields about 1 ton of carbon dioxide (CO2) emissions, of which calcination of limestone and the combustion of fuels each contribute about half. The overall level of CO2 output makes the cement industry one of the top two manufacturing industry sources of greenhouse gases; however, in many countries, the cement industry's contribution is a small fraction of that from fossil fuel combustion by power plants and motor vehicles. The nature of clinker and the enormous heat requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels, thus providing the opportunity to apply key concepts of industrial ecology, most notably the closing of loops through the use of by-products of other industries (industrial symbiosis). In this article, the chemistry and technology of cement manufacture are summarized. In a forthcoming companion article (part II), some of the environmental challenges and opportunities facing the cement industry are described. Because of the size and scope of the U.S. cement industry, the analysis relies primarily on data and practices from the United States.

  3. Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

    PubMed

    Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

    2016-01-01

    The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix. PMID:26601731

  4. Stromatolites, ooid dunes, hardgrounds, and crusted mud beds, all products of marine cementation and microbial mats in subtidal oceanic mixing zone on eastern margin of Great Bahama Bank

    SciTech Connect

    Dill, R.F.; Kendall, C.S.C.G.; Steinen, R.P.

    1989-03-01

    The interisland channels along the eastern margin of the Great Bahamas Bank contain lithified structures that owe their origin to recent marine cementation. This cementation appears to be commonly associated with a complex microbial community of plants and microorganisms living within a bank-margin oceanographic mixing zone. In this region, reversing tidal and wind-driven currents flow up to 3 knots (150 cm/sec) three hours out of each six-hour tidal period. Here, marine-cement crusted, carbonate mud beds are found interbedded within migrating ooid sand bars and dunes and are associated with growing, lithified stromatolites up to 2 m in height. These laminated mud beds are found with thicknesses of up to 1 m in subtidal depths of 4 to 8 m (12 to 25 ft). The muds appear to be homogeneous, but closer examination by SEM and under a microscope reveals they are composed of pelletoid aggregates of needle-shaped aragonite crystals with diameters of up to 50 ..mu... The size of these soft pellets is similar to the smaller grains of ooid sands that are abundant in the area. This size similarity could explain why both the mud beds are found in similar high-energy hydraulic regimes as the ooid sands, but does not suggest how or why the aggregates of pure aragonite needles form. A high production of ooid sand within this bank margin environment permits the formation of natural levees along the margins of tidal channels. The back sides of these levees are being lithified by marine cements to form hardgrounds. Skeletal and ooid sand dunes stabilized by Thallasia in channel bottoms also are becoming lithified. Grapestones form at the distributaries of flood tidal deltas of ooid sand. All of these features have a common attribute: they are continually in contact with the turbulent mixing-zone waters.

  5. Generative inspection process planner for integrated production

    SciTech Connect

    Brown, C.W. . Kansas City Div.); Gyorog, D.A. . Dept. of Mechanical Engineering)

    1990-04-01

    This work describes the design prototype development of a generative process planning system for dimensional inspection. The system, IPPEX (Inspection Process Planning EXpert), is a rule-based expert system for integrated production. Using as advanced product modeler, relational databases, and artificial intelligence techniques, IPPEX generates the process plan and part program for the dimensional inspection of products using CMMs. Through an application interface, the IPPEX system software accesses product definition from the product modeler. The modeler is a solid geometric modeler coupled with a dimension and tolerance modeler. Resource data regarding the machines, probes, and fixtures are queried from databases. IPPEX represents inspection process knowledge as production rules and incorporates an embedded inference engine to perform decision making. The IPPEX system, its functional architecture, system architecture, system approach, product modeling environment, inspection features, inspection knowledge, hierarchical planning strategy, user interface formats, and other fundamental issues related to inspection planning and part programming for CMMs are described. 27 refs., 16 figs., 4 tabs.

  6. Biotechnology in Food Production and Processing

    NASA Astrophysics Data System (ADS)

    Knorr, Dietrich; Sinskey, Anthony J.

    1985-09-01

    The food processing industry is the oldest and largest industry using biotechnological processes. Further development of food products and processes based on biotechnology depends upon the improvement of existing processes, such as fermentation, immobilized biocatalyst technology, and production of additives and processing aids, as well as the development of new opportunities for food biotechnology. Improvements are needed in the characterization, safety, and quality control of food materials, in processing methods, in waste conversion and utilization processes, and in currently used food microorganism and tissue culture systems. Also needed are fundamental studies of the structure-function relationship of food materials and of the cell physiology and biochemistry of raw materials.

  7. Surface pretreatment for prolonged survival of cemented tibial prosthesis components: full- vs. surface-cementation technique

    PubMed Central

    Marx, Rudolf; Qunaibi, Mutaz; Wirtz, Dieter Christian; Niethard, Fritz Uwe; Mumme, Thorsten

    2005-01-01

    Background One of few persisting problems of cemented total knee arthroplasty (TKA) is aseptic loosening of tibial component due to degradation of the interface between bone cement and metallic tibial shaft component, particularly for surface cemented tibial components. Surface cementation technique has important clinical meaning in case of revision and for avoidance of stress shielding. Degradation of the interface between bone cement and bone may be a secondary effect due to excessive crack formation in bone cement starting at the opposite metallic surface. Methods This study was done to prove crack formation in the bone cement near the metallic surface when this is not coated. We propose a newly developed coating process by PVD layering with SiOx to avoid that crack formation in the bone cement. A biomechanical model for vibration fatigue test was done to simulate the physiological and biomechanical conditions of the human knee joint and to prove excessive crack formation. Results It was found that coated tibial components showed a highly significant reduction of cement cracking near the interface metal/bone cement (p < 0.01) and a significant reduction of gap formation in the interface metal-to-bone cement (p < 0.05). Conclusion Coating dramatically reduces hydrolytic- and stress-related crack formation at the prosthesis interface metal/bone cement. This leads to a more homogenous load transfer into the cement mantle which should reduce the frequency of loosening in the interfaces metal/bone cement/bone. With surface coating of the tibial component it should become possible that surface cemented TKAs reveal similar loosening rates as TKAs both surface and stem cemented. This would be an important clinical advantage since it is believed that surface cementing reduces metaphyseal bone loss in case of revision and stress shielding for better bone health. PMID:16262888

  8. 76 FR 12370 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... pursuant to Section 6(b) of the Act on February 5, 1985 (50 FR 5015). The last notification was filed with... Section 6(b) of the Act January 27, 2010 (75 FR 4423). Patricia A. Brink, Director of Civil Enforcement... Cement Association Notice is hereby given that, on February 02, 2011, pursuant to Section 6(a) of...

  9. 77 FR 5573 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... February 5, 1985 (50 FR 5015). The last notification was filed with the Department on May 12, 2011. A notice was published in the Federal Register pursuant to Section 6(b) of the Act on June 13, 2011 (76 FR...; Concrete Promotion Council of Northern California, Roseville, CA; and Slag Cement Association, Sugar...

  10. Integration of software process and product quality

    SciTech Connect

    Schneidewind, N.F.

    1996-12-31

    If we could integrate software process with software quality we would make a significant improvement in customer satisfaction with industry`s products because then the developer would know which process steps lead to improvements in product quality. Unfortunately, many of the claims of the contribution of process to product quality are based on belief and not scientific evidence. This is not a criticism - just a statement of fact. Unlike physics, it is difficult to perform a controlled experiment in a large software organization when that very organization must continue to develop the product. For example, it would be very difficult to fix all the design and testing procedures, except for a change in the thoroughness of software inspections, and measure quality for the same component of software, before and after the more rigorous inspection process is employed. However if we could track product quality over a long period of time, during which a series of process improvement have been made, then in the aggregate, we could come to some conclusions about the process-product relationship. Furthermore, because product complexity usually increases with subsequent releases (e.g., computer operating system), it would also be of interest to track product complexity over time. This is desirable because if we can show that product quality improves over time, during which a number of process improvements have been made, despite increasing complexity, it would add credence to the argument that in the aggregate the improvements in process have contributed to improvements in product quality. As an example of the integration of process with product and the measurement approach described above we analyze thirteen years worth of process and product data for the NASA Space Shuttle and its software organization - a Capability Maturity Model Level Five organization.

  11. Sustainable development of the cement industry and blended cements to meet ecological challenges.

    PubMed

    Sobolev, Konstantin

    2003-05-01

    The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and--at the same time--uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement. PMID:12806096

  12. Low-temperature ceramic radioactive waste form characteriztion of supercalcine-based monazite-cement composites

    SciTech Connect

    Roy, D.M.; Wakeley, L.D.; Atkinson, S.D.

    1980-04-18

    Simulated radioactive waste solidification by a lower temperature ceramic (cement) process is being investigated. The monazite component (simulated by NdPO/sub 4/) of supercalcine-ceramic has been solidified in cement and found to generate a solid form with low leachability. Several types of commercial cements and modifications thereof were used. No detectable release of Nd or P was found through characterizing the products of accelerated hydrothermal leaching at 473/sup 0/K (200/sup 0/C) and 30.4 MPa (300 bars) pressure.

  13. Micro- and nano-scale characterization to study the thermal degradation of cement-based materials

    SciTech Connect

    Lim, Seungmin Mondal, Paramita

    2014-06-01

    The degradation of hydration products of cement is known to cause changes in the micro- and nano-structure, which ultimately drive thermo-mechanical degradation of cement-based composite materials at elevated temperatures. However, a detailed characterization of these changes is still incomplete. This paper presents results of an extensive experimental study carried out to investigate micro- and nano-structural changes that occur due to exposure of cement paste to high temperatures. Following heat treatment of cement paste up to 1000 °C, damage states were studied by compressive strength test, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) atomic force microscopy (AFM) and AFM image analysis. Using experimental results and research from existing literature, new degradation processes that drive the loss of mechanical properties of cement paste are proposed. The development of micro-cracks at the interface between unhydrated cement particles and paste matrix, a change in C–S–H nano-structure and shrinkage of C–S–H, are considered as important factors that cause the thermal degradation of cement paste. - Highlights: • The thermal degradation of hydration products of cement is characterized at micro- and nano-scale using scanning electron microscopy (SEM) and atomic force microscopy (AFM). • The interface between unhydrated cement particles and the paste matrix is considered the origin of micro-cracks. • When cement paste is exposed to temperatures above 300 ºC, the nano-structure of C-S-H becomes a more loosely packed globular structure, which could be indicative of C-S-H shrinkage.

  14. Cementing multilateral wells with latex cement

    SciTech Connect

    1997-08-01

    A multilateral well is a well with one or more branches or lateral sections extending from its main wellbore. The laterals can be openhole or cased hole. When laterals are cased hole, the cement integrity for casing support and zonal isolation is very important. When cementing the lateral sections of multilateral wells, it is important to use a cement with high strength and durability to support the liner throughout the life of the well and to support the lateral section. The cement column is subjected to various stresses when the cemented inner stub is cut. High tensile strength, flexural strength, and crack resistance are required. These properties are necessary to make a clean cut through the cement sheath that does not induce cracks in the cement column. Latex cement is commonly used for its gas-migration-control property.

  15. Process for improving metal production in steelmaking processes

    DOEpatents

    Pal, U.B.; Gazula, G.K.M.; Hasham, A.

    1996-06-18

    A process and apparatus for improving metal production in ironmaking and steelmaking processes is disclosed. The use of an inert metallic conductor in the slag containing crucible and the addition of a transition metal oxide to the slag are the disclosed process improvements. 6 figs.

  16. Process for improving metal production in steelmaking processes

    DOEpatents

    Pal, Uday B. (Malden, MA); Gazula, Gopala K. M. (Somerville, MA); Hasham, Ali (Karachi, PK)

    1996-01-01

    A process and apparatus for improving metal production in ironmaking and steelmaking processes is disclosed. The use of an inert metallic conductor in the slag containing crucible and the addition of a transition metal oxide to the slag are the disclosed process improvements.

  17. Polymerization eficiency of dual-polymerized resin cements light-irradiated through ceramics and laboratory-processed resin composite.

    PubMed

    Papazoglou, Efstratios; Rahiotis, Chris; Kakaboura, Afrodite; Loukidis, Michael

    2008-03-01

    The purpose of the study was to determine the influence of light-irradiation through two ceramic and one resin composite materials on the degree of remaining double carbon bonds in 3 dual-polymerized resin cements. After mixing, the cement was inserted into a 0.5 mm deep recess in a silicon mold, covered with one ceramic or resin composite rectangular block and exposed through the block with the light from a halogen polymerization unit for 40 s. Infrared spectroscopic analysis was used to record the degree of remaining double carbon bonds. Light irradiation through 2 mm-thick ceramic and resin composite materials increased the degree of remaining double carbon bonds relative to the direct photopolymerization analogues. PMID:18468320

  18. Guidebook for Using the Tool BEST Cement: Benchmarking and Energy Savings Tool for the Cement Industry

    SciTech Connect

    Galitsky, Christina; Price, Lynn; Zhou, Nan; Fuqiu , Zhou; Huawen, Xiong; Xuemin, Zeng; Lan, Wang

    2008-07-30

    The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per year); (5) the amount of production of cement by type and grade (in tonnes per year); (6) the electricity generated onsite; and, (7) the energy used by fuel type; and, the amount (in RMB per year) spent on energy. The tool offers the user the opportunity to do a quick assessment or a more detailed assessment--this choice will determine the level of detail of the energy input. The detailed assessment will require energy data for each stage of production while the quick assessment will require only total energy used at the entire facility (see Section 6 for more details on quick versus detailed assessments). The benchmarking tool provides two benchmarks--one for Chinese best practices and one for international best practices. Section 2 describes the differences between these two and how each benchmark was calculated. The tool also asks for a target input by the user for the user to set goals for the facility.

  19. Cement Kiln Flue Gas Recovery Scrubber Project

    SciTech Connect

    National Energy Technology Laboratory

    2001-11-30

    The Cement Kiln Flue Gas Recovery Scrubber Project was a technical success and demonstrated the following: CKD can be used successfully as the sole reagent for removing SO2 from cement kiln flue gas, with removal efficiencies of 90 percent or greater; Removal efficiencies for HCl and VOCs were approximately 98 percent and 70 percent, respectively; Particulate emissions were low, in the range of 0.005 to 0.007 grains/standard cubic foot; The treated CKD sorbent can be recycled to the kiln after its potassium content has been reduced in the scrubber, thereby avoiding the need for landfilling; The process can yield fertilizer-grade K2SO4, a saleable by-product; and Waste heat in the flue gas can provide the energy required for evaporation and crystallization in the by-product recovery operation. The demonstration program established the feasibility of using the Recovery Scrubber{trademark} for desulfurization of flue gas from cement kilns, with generally favorable economics, assuming tipping fees are available for disposal of ash from biomass combustion. The process appears to be suitable for commercial use on any type of cement kiln. EPA has ruled that CKD is a nonhazardous waste, provided the facility meets Performance Standards for the Management of CKD (U.S. Environmental Protection Agency 1999d). Therefore, regulatory drivers for the technology focus more on reduction of air pollutants and pollution prevention, rather than on treating CKD as a hazardous waste. Application of the Recovery Scrubbe{trademark} concept to other waste-disposal operations, where pollution and waste reductions are needed, appears promising.

  20. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    SciTech Connect

    Dady Dadyburjor; Philip R. Biedler; Chong Chen; L. Mitchell Clendenin; Manoj Katakdaunde; Elliot B. Kennel; Nathan D. King; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2004-08-31

    This Department of Energy National Energy Technology Laboratory sponsored project developed carbon products, using mildly hydrogenated solvents to extract the organic portion of coal to create synthetic pitches, cokes, carbon foam and carbon fibers. The focus of this effort was on development of lower cost solvents, milder hydrogenation conditions and improved yield in order to enable practical production of these products. This technology is needed because of the long-term decline in production of domestic feedstocks such as petroleum pitch and coal tar pitch. Currently, carbon products represents a market of roughly 5 million tons domestically, and 19 million tons worldwide. Carbon products are mainly derived from feedstocks such as petroleum pitch and coal tar pitch. The domestic supply of petroleum pitch is declining because of the rising price of liquid fuels, which has caused US refineries to maximize liquid fuel production. As a consequence, the long term trend has a decline in production of petroleum pitch over the past 20 years. The production of coal tar pitch, as in the case of petroleum pitch, has likewise declined significantly over the past two decades. Coal tar pitch is a byproduct of metallurgical grade coke (metcoke) production. In this industry, modern metcoke facilities are recycling coal tar as fuel in order to enhance energy efficiency and minimize environmental emissions. Metcoke production itself is dependent upon the production requirements for domestic steel. Hence, several metcoke ovens have been decommissioned over the past two decades and have not been replaced. As a consequence sources of coal tar are being taken off line and are not being replaced. The long-term trend is a reduction in coal tar pitch production. Thus import of feedstocks, mainly from Eastern Europe and China, is on the rise despite the relatively large transportation cost. To reverse this trend, a new process for producing carbon products is needed. The process must be economically competitive with current processes, and yet be environmentally friendly as well. The solvent extraction process developed uses mild hydrogenation of low cost oils to create powerful solvents that can dissolve the organic portion of coal. The insoluble portion, consisting mainly of mineral matter and fixed carbon, is removed via centrifugation or filtration, leaving a liquid solution of coal chemicals and solvent. This solution can be further refined via distillation to meet specifications for products such as synthetic pitches, cokes, carbon foam and fibers. The most economical process recycles 85% of the solvent, which itself is obtained as a low-cost byproduct from industrial processes such as coal tar or petroleum refining. Alternatively, processes have been developed that can recycle 100% of the solvent, avoiding any need for products derived from petroleum or coal tar.

  1. Early diagenetic alunite group mineral cements and alteration products of the Camp Rice Formation (Plio-Pleistocene) southern Rio Grande Rift

    SciTech Connect

    Harris, M.J.; James, W.C. ); Mack, G.H. . Dept. of Earth Sciences)

    1992-01-01

    Early diagenetic alunite group mineral cements and grain alteration products have been identified within the Camp Rice axial-fluvial facies west of Las Cruces, New Mexico. These constituents are pervasive and occur as pore occluding aggregates of euhedral crystals 5--15 [mu]m in diameter or as a finely disseminated mix with other authigenic minerals and alteration products. Approximately 19% of the total alunite is intragranular and replaces primarily volcanic rock fragments and feldspars. The diagenetic event was highly destructive to the original detrital constituents. An inferred initial average composition of Q[sub 47]F[sub 21]I[sub 32] from well indurated adjacent, calcite cemented strata of similar grain size has been altered to a composition of Q[sub 59]F[sub 20]L[sub 21]. Individual sandstone bodies exhibit a vertical zonation of cements from a lower alunite-natroalunite-gypsum assemblage to an overlying jarosite-kaolinite-silica assemblage. Jarosite-dominated strata are distinctly better indurated along the foresets and bases of individual cross-bed sets than alunite-dominated strata suggesting preferential precipitation of the former within initially higher permeability zones. The alunite group mineral constituents are believed to have developed under acidic and oxidizing conditions in a nearsurface environment. Jarosite likely formed under more acidic and oxidizing conditions than the alunite. Ascending hydrothermal waters rich in H[sub 2]S provided the necessary sulfate. The hydrothermal waters may have already been acidic or were acidified by the oxidation of H[sub 2]S. Descending oxidized meteoric waters flowing along permeable conduits and mixing with the hydrothermal waters likely controlled Eh and therefore pH of the diagenetic environment. Many of the necessary cations for alunite and jarosite genesis probably resulted from local hydrolysis of feldspars and volcanic rock fragments.

  2. Advanced Multi-Product Coal Utilization By-Product Processing Plant

    SciTech Connect

    Thomas Robl; John Groppo

    2009-06-30

    The overall objective of this project is to design, construct, and operate an ash beneficiation facility that will generate several products from coal combustion ash stored in a utility ash pond. The site selected is LG&E's Ghent Station located in Carroll County, Kentucky. The specific site under consideration is the lower ash pond at Ghent, a closed landfill encompassing over 100 acres. Coring activities revealed that the pond contains over 7 million tons of ash, including over 1.5 million tons of coarse carbon and 1.8 million tons of fine (<10 {micro}m) glassy pozzolanic material. These potential products are primarily concentrated in the lower end of the pond adjacent to the outlet. A representative bulk sample was excavated for conducting laboratory-scale process testing while a composite 150 ton sample was also excavated for demonstration-scale testing at the Ghent site. A mobile demonstration plant with a design feed rate of 2.5 tph was constructed and hauled to the Ghent site to evaluate unit processes (i.e. primary classification, froth flotation, spiral concentration, secondary classification, etc.) on a continuous basis to determine appropriate scale-up data. Unit processes were configured into four different flowsheets and operated at a feed rate of 2.5 tph to verify continuous operating performance and generate bulk (1 to 2 tons) products for product testing. Cementitious products were evaluated for performance in mortar and concrete as well as cement manufacture process addition. All relevant data from the four flowsheets was compiled to compare product yields and quality while preliminary flowsheet designs were generated to determine throughputs, equipment size specifications and capital cost summaries. A detailed market study was completed to evaluate the potential markets for cementitious products. Results of the study revealed that the Ghent local fly ash market is currently oversupplied by more than 500,000 tpy and distant markets (i.e. Florida) are oversupplied as well. While the total US demand for ultrafine pozzolan is currently equal to demand, there is no reason to expect a significant increase in demand. Despite the technical merits identified in the pilot plant work with regard to beneficiating the entire pond ash stream, market developments in the Ohio River Valley area during 2006-2007 were not conducive to demonstrating the project at the scale proposed in the Cooperative Agreement. As a result, Cemex withdrew from the project in 2006 citing unfavorable local market conditions in the foreseeable future at the demonstration site. During the Budget Period 1 extensions provided by the DOE, CAER has contacted several other companies, including cement producers and ash marketing concerns for private cost share. Based on the prevailing demand-supply situation, these companies had expressed interest only in limited product lines, rather than the entire ash beneficiation product stream. Although CAER had generated interest in the technology, a financial commitment to proceed to Budget Period 2 could not be obtained from private companies. Furthermore, the prospects of any decisions being reached within a reasonable time frame were dim. Thus, CAER concurred with the DOE to conclude the project at the end of Budget Period 1, March 31, 2007. The activities presented in this report were carried out during the Cooperative Agreement period 08 November 2004 through 31 March 2007.

  3. Fluid loss control in well cement slurries

    SciTech Connect

    Roark, D.N.; Nugent, A. Jr.; Bandlish, B.K.

    1987-11-17

    In a process of cementing subterranean well formations employing an aqueous well cement slurry, this patent describes the improvement characterized in that the slurry contains a gelatinous material that tends to plug porous zones and minimize premature water loss from the well cement slurry when present in the subterranean well formation. The gelatinous material is formed by interaction in the presence of water between (i) a sulfonated polymer and (ii) a polymer of monoallylamine.

  4. Mariner 9-Image processing and products

    USGS Publications Warehouse

    Levinthal, E.C.; Green, W.B.; Cutts, J.A.; Jahelka, E.D.; Johansen, R.A.; Sander, M.J.; Seidman, J.B.; Young, A.T.; Soderblom, L.A.

    1973-01-01

    The purpose of this paper is to describe the system for the display, processing, and production of image-data products created to support the Mariner 9 Television Experiment. Of necessity, the system was large in order to respond to the needs of a large team of scientists with a broad scope of experimental objectives. The desire to generate processed data products as rapidly as possible to take advantage of adaptive planning during the mission, coupled with the complexities introduced by the nature of the vidicon camera, greatly increased the scale of the ground-image processing effort. This paper describes the systems that carried out the processes and delivered the products necessary for real-time and near-real-time analyses. References are made to the computer algorithms used for the, different levels of decalibration and analysis. ?? 1973.

  5. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-07-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that was performed to analyze the alkali-silica reactivity of ULHS in cement slurries.

  6. Immobilisation of heavy metal in cement-based solidification/stabilisation: A review

    SciTech Connect

    Chen, Q.Y. Tyrer, M.; Hills, C.D.; Yang, X.M.; Carey, P.

    2009-01-15

    Heavy metal-bearing waste usually needs solidification/stabilization (s/s) prior to landfill to lower the leaching rate. Cement is the most adaptable binder currently available for the immobilisation of heavy metals. The selection of cements and operating parameters depends upon an understanding of chemistry of the system. This paper discusses interactions of heavy metals and cement phases in the solidification/stabilisation process. It provides a clarification of heavy metal effects on cement hydration. According to the decomposition rate of minerals, heavy metals accelerate the hydration of tricalcium silicate (C{sub 3}S) and Portland cement, although they retard the precipitation of portlandite due to the reduction of pH resulted from hydrolyses of heavy metal ions. The chemical mechanism relevant to the accelerating effect of heavy metals is considered to be H{sup +} attacks on cement phases and the precipitation of calcium heavy metal double hydroxides, which consumes calcium ions and then promotes the decomposition of C{sub 3}S. In this work, molecular models of calcium silicate hydrate gel are presented based on the examination of {sup 29}Si solid-state magic angle spinning/nuclear magnetic resonance (MAS/NMR). This paper also reviews immobilisation mechanisms of heavy metals in hydrated cement matrices, focusing on the sorption, precipitation and chemical incorporation of cement hydration products. It is concluded that further research on the phase development during cement hydration in the presence of heavy metals and thermodynamic modelling is needed to improve effectiveness of cement-based s/s and extend this waste management technique.

  7. Benchmarking Peer Production Mechanisms, Processes & Practices

    ERIC Educational Resources Information Center

    Fischer, Thomas; Kretschmer, Thomas

    2008-01-01

    This deliverable identifies key approaches for quality management in peer production by benchmarking peer production practices and processes in other areas. (Contains 29 footnotes, 13 figures and 2 tables.)[This report has been authored with contributions of: Kaisa Honkonen-Ratinen, Matti Auvinen, David Riley, Jose Pinzon, Thomas Fischer, Thomas

  8. Cell culture processes for monoclonal antibody production

    PubMed Central

    Li, Feng; Vijayasankaran, Natarajan; Shen, Amy (Yijuan); Kiss, Robert

    2010-01-01

    Animal cell culture technology has advanced significantly over the last few decades and is now generally considered a reliable, robust and relatively mature technology. A range of biotherapeutics are currently synthesized using cell culture methods in large scale manufacturing facilities that produce products for both commercial use and clinical studies. The robust implementation of this technology requires optimization of a number of variables, including (1) cell lines capable of synthesizing the required molecules at high productivities that ensure low operating cost; (2) culture media and bioreactor culture conditions that achieve both the requisite productivity and meet product quality specifications; (3) appropriate on-line and off-line sensors capable of providing information that enhances process control; and (4) good understanding of culture performance at different scales to ensure smooth scale-up. Successful implementation also requires appropriate strategies for process development, scale-up and process characterization and validation that enable robust operation and ensure compliance with current regulations. This review provides an overview of the state-of-the art technology in key aspects of cell culture, e.g., generation of highly productive cell lines and optimization of cell culture process conditions. We also summarize the current thinking on appropriate process development strategies and process advances that might affect process development. PMID:20622510

  9. Development of strength in cements

    NASA Astrophysics Data System (ADS)

    Matkovic, B.

    1981-04-01

    The production of doped belite (dicalcium silicate) clinkers as a prospective means for saving energy in Portland cement production is described. This is accomplished by small additions of either barium sulfate (BaSO4), calcium tribasic phosphate (Ca5(PO4)3OH), or vanadium oxide (V2O5) to belite (Ca2SiO4) clinker. In addition to conserving energy, doping the belite with barium sulfate imparts greater strength to the resulting modified belite. Reactants, additives, and factors contributing to the fabrication of Sorel cement are described.

  10. Processes, Products, and Measures of Memory Organization.

    ERIC Educational Resources Information Center

    Pellegrino, James W.; Ingram, Albert L.

    Some of the issues associated with the lack of a precisely stated theory of memory organization are considered. The first section provides an overview of the concept of organization. Emphasis is on problems associated with the definition of organization, especially the distinction between organization as a process and as the product of a process.

  11. A corporate product integrity assurance process.

    PubMed

    Weiler, E D; Keener, R

    1991-10-01

    One of the more difficult challenges that confronts the chemical industry throughout the industrialized world is how to effectively manage the various and often diverse regulatory requirements. What follows is a description of a process designed to help with new product introductions. The process is generic and is applicable to almost any corporate environment and structure. PMID:1669968

  12. Tires fuel oil field cement manufacturing

    SciTech Connect

    Caveny, B.; Ashford, D.; Garcia, J.G.; Hammack, R.

    1998-08-31

    In a new process, waste automobile tires added to the fuel mix of gas, coal, and coke help fire kilns to produce API-quality oil field cement. Capital Cement uses this process in its cement-manufacturing plant in San Antonio, in which it also produces construction cement. The tires provide a lower-cost fuel and boost the temperature at a critical stage in the kiln burn process. Also, steel-belted tires add iron content to the mix. According to lab results, tire-burned cement slurries will perform the same as conventionally burned cement slurries. Actual field applications have proven that cement produced by burning tires performs no different than conventionally produced slurries. Capital`s plant uses both dry and wet processes, with separate kilns running both processes at the same time. Cement clinker is partially fired by waste tires in both kiln processes. The tires represent 12% of the fuel consumed by the plant, a number that is expected to increase. Capital burns about 200 tires/hr, or about 1.6 million tires/year.

  13. Strength properties of refractory mortar with an aluminoborophosphate bond during the cementing of mullite-corundum and fireclay products

    SciTech Connect

    Kliment'eva, V.S.; Filimonova, N.I.; Baranova, T.F.; Grishina, N.E>

    1988-09-01

    A study was conducted of a refractory mortar having a mullite-corundum-zirconia composition with an aluminoborophosphate bond for cementing mullite-corundum blocks, corundum and chamotte (fireclay) bricks. The blocks were made by water casting of mullite containing suspensions with the introduction of finely milled electrocorundum. The bonding capacity of the refractory mortar was assessed by testing bonded specimens for shear and bending strengths. It is shown that the highest shear strengths are possessed by mullite-corundum blocks fired at 1823/sup 0/K. The fired model of block construction made from blocks after drying is shown; the form and design correspond to the planned requirements.

  14. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    SciTech Connect

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-01-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission's Technical Position on Waste Form'' (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity.

  15. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    SciTech Connect

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-08-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission`s ``Technical Position on Waste Form`` (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity.

  16. Critical elements in implementations of just-in-time management: empirical study of cement industry in Pakistan.

    PubMed

    Qureshi, Muhammad Imran; Iftikhar, Mehwish; Bhatti, Mansoor Nazir; Shams, Tauqeer; Zaman, Khalid

    2013-01-01

    In recent years, inventory management is continuous challenge for all organizations not only due to heavy cost associated with inventory holding, but also it has a great deal to do with the organizations production process. Cement industry is a growing sector of Pakistan's economy which is now facing problems in capacity utilization of their plants. This study attempts to identify the key strategies for successful implementation of just-in-time (JIT) management philosophy on the cement industry of Pakistan. The study uses survey responses from four hundred operations' managers of cement industry in order to know about the advantages and benefits that cement industry have experienced by Just in time (JIT) adoption. The results show that implementing the quality, product design, inventory management, supply chain and production plans embodied through the JIT philosophy which infect enhances cement industry competitiveness in Pakistan. JIT implementation increases performance by lower level of inventory, reduced operations & inventory costs was reduced eliminates wastage from the processes and reduced unnecessary production which is a big challenge for the manufacturer who are trying to maintain the continuous flow processes. JIT implementation is a vital manufacturing strategy that reaches capacity utilization and minimizes the rate of defect in continuous flow processes. The study emphasize the need for top management commitment in order to incorporate the necessary changes that need to take place in cement industry so that JIT implementation can take place in an effective manner. PMID:24340248

  17. Carbon nanotube mass production: principles and processes.

    PubMed

    Zhang, Qiang; Huang, Jia-Qi; Zhao, Meng-Qiang; Qian, Wei-Zhong; Wei, Fei

    2011-07-18

    Our society requires new materials for a sustainable future, and carbon nanotubes (CNTs) are among the most important advanced materials. This Review describes the state-of-the-art of CNT synthesis, with a focus on their mass-production in industry. At the nanoscale, the production of CNTs involves the self-assembly of carbon atoms into a one-dimensional tubular structure. We describe how this synthesis can be achieved on the macroscopic scale in processes akin to the continuous tonne-scale mass production of chemical products in the modern chemical industry. Our overview includes discussions on processing methods for high-purity CNTs, and the handling of heat and mass transfer problems. Manufacturing strategies for agglomerated and aligned single-/multiwalled CNTs are used as examples of the engineering science of CNT production, which includes an understanding of their growth mechanism, agglomeration mechanism, reactor design, and process intensification. We aim to provide guidelines for the production and commercialization of CNTs. Although CNTs can now be produced on the tonne scale, knowledge of the growth mechanism at the atomic scale, the relationship between CNT structure and application, and scale-up of the production of CNTs with specific chirality are still inadequate. A multidisciplinary approach is a prerequisite for the sustainable development of the CNT industry. PMID:21732544

  18. Early age hydration and pozzolanic reaction in natural zeolite blended cements: Reaction kinetics and products by in situ synchrotron X-ray powder diffraction

    SciTech Connect

    Snellings, R.; Mertens, G.; Cizer, O.; Elsen, J.

    2010-12-15

    The in situ early-age hydration and pozzolanic reaction in cements blended with natural zeolites were investigated by time-resolved synchrotron X-ray powder diffraction with Rietveld quantitative phase analysis. Chabazite and Na-, K-, and Ca-exchanged clinoptilolite materials were mixed with Portland cement in a 3:7 weight ratio and hydrated in situ at 40 {sup o}C. The evolution of phase contents showed that the addition of natural zeolites accelerates the onset of C{sub 3}S hydration and precipitation of CH and AFt. Kinetic analysis of the consumption of C{sub 3}S indicates that the enveloping C-S-H layer is thinner and/or less dense in the presence of alkali-exchanged clinoptilolite pozzolans. The zeolite pozzolanic activity is interpreted to depend on the zeolite exchangeable cation content and on the crystallinity. The addition of natural zeolites alters the structural evolution of the C-S-H product. Longer silicate chains and a lower C/S ratio are deduced from the evolution of the C-S-H b-cell parameter.

  19. Renewable hydrogen production for fossil fuel processing

    SciTech Connect

    Greenbaum, E.

    1994-09-01

    The objective of this mission-oriented research program is the production of renewable hydrogen for fossil fuel processing. This program will build upon promising results that have been obtained in the Chemical Technology Division of Oak Ridge National Laboratory on the utilization of intact microalgae for photosynthetic water splitting. In this process, specially adapted algae are used to perform the light-activated cleavage of water into its elemental constituents, molecular hydrogen and oxygen. The great potential of hydrogen production by microalgal water splitting is predicated on quantitative measurement of their hydrogen-producing capability. These are: (1) the photosynthetic unit size of hydrogen production; (2) the turnover time of photosynthetic hydrogen production; (3) thermodynamic efficiencies of conversion of light energy into the Gibbs free energy of molecular hydrogen; (4) photosynthetic hydrogen production from sea water using marine algae; (5) the original development of an evacuated photobiological reactor for real-world engineering applications; (6) the potential for using modern methods of molecular biology and genetic engineering to maximize hydrogen production. The significance of each of these points in the context of a practical system for hydrogen production is discussed. This program will be enhanced by collaborative research between Oak Ridge National Laboratory and senior faculty members at Duke University, the University of Chicago, and Iowa State University. The special contribution that these organizations and faculty members will make is access to strains and mutants of unicellular algae that will potentially have useful properties for hydrogen production by microalgal water splitting.

  20. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  1. Process redesign of production maintenance operations

    SciTech Connect

    Rankin, M.; Lowe, B.; Disney, V. Spilman, K.

    1995-12-31

    This paper describes a methodology for the systematic redesign of traditional production maintenance operations as they relate to subsurface failures of sucker rod pumped wells. The paper advocates an organized approach to process definition, refinement and redesign such that improvement objectives are clearly communicated, appropriate human and physical resources are brought to bear, and a system of improvement measurements becomes the overriding focus of the operation. Specific examples of the use of statistical process control tools in the production maintenance quality improvement effort are explored.

  2. The effects of the mechanical–chemical stabilization process for municipal solid waste incinerator fly ash on the chemical reactions in cement paste

    SciTech Connect

    Chen, Cheng-Gang; Sun, Chang-Jung; Gau, Sue-Huai; Wu, Ching-Wei; Chen, Yu-Lun

    2013-04-15

    Highlights: ► Milling extracted MSWI fly ash. ► Increasing specific surface area, destruction of the crystalline texture, and increasing the amount of amorphous materials. ► Increasing heavy metal stability. ► Inducing pozzolanic reactions and increasing the early and later strength of the cement paste. - Abstract: A water extraction process can remove the soluble salts present in municipal solid waste incinerator (MSWI) fly ash, which will help to increase the stability of the synthetic materials produced from the MSWI fly ash. A milling process can be used to stabilize the heavy metals found in the extracted MSWI fly ash (EA) leading to the formation of a non-hazardous material. This milled extracted MSWI fly ash (MEA) was added to an ordinary Portland cement (OPC) paste to induce pozzolanic reactions. The experimental parameters included the milling time (96 h), water to binder ratios (0.38, 0.45, and 0.55), and curing time (1, 3, 7 and 28 days). The analysis procedures included inductively coupled plasma atomic emission spectroscopy (ICP/AES), BET, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) imaging. The results of the analyses indicate that the milling process helped to stabilize the heavy metals in the MEA, with an increase in the specific surface area of about 50 times over that of OPC. The addition of the MEA to the OPC paste decreased the amount of Ca(OH){sub 2} and led to the generation of calcium–silicate–hydrates (C–S–H) which in turned increased the amount of gel pores and middle sized pores in the cement. Furthermore, a comparison shows an increase in the early and later strength over that of OPC paste without the addition of the milled extracted ash. In other words, the milling process could stabilize the heavy metals in the MEA and had an activating effect on the MEA, allowing it to partly substitute OPC in OPC paste.

  3. Effects of DCPD cement chemistry on degradation properties and cytocompatibility: comparison of MCPM/?-TCP and MCPM/HA formulations.

    PubMed

    Alge, Daniel L; Goebel, W Scott; Chu, Tien-Min Gabriel

    2013-04-01

    Dicalcium phosphate dihydrate (DCPD) cements are attractive biomaterials for bone repair, and a number of different DCPD cement formulations have been proposed in the literature. In this study, we have specifically compared monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) and MCPM/?-tricalcium phosphate (?-TCP) formulations to test the hypothesis that DCPD cement chemistry affects the degradation properties and cytocompatibility of the cement. Using simple in vitro models we found that MCPM/?-TCP formulations degraded primarily by DCPD dissolution, which was associated with a slight pH drop and relatively low mass loss. Cytocompatibility testing of cement conditioned culture media revealed no significant change in cell viability relative to the negative control for all of the MCPM/?-TCP formulations. In contrast, the MCPM/HA formulations were prone to undergo rapid conversion of DCPD to HA, resulting in a sharp pH drop and extensive mass loss. A stoichiometric excess of HA in the cement was found to accelerate the conversion process, and significant cytotoxicity was observed for the MCPM/HA formulations containing excess HA. Collectively, these results show that, although the product of the setting reaction is the same, DCPD cements produced with MCPM/HA and MCPM/?-TCP formulations differ significantly in their degradation properties and cytocompatibility. These differences may have important implications for the selection of a DCPD cement formulation for clinical application. PMID:23428798

  4. Effects of DCPD Cement Chemistry on Degradation Properties and Cytocompatibility: Comparison of MCPM/?-TCP and MCPM/HA Formulations

    PubMed Central

    Alge, Daniel L.; Goebel, W. Scott; Chu, Tien-Min Gabriel

    2013-01-01

    Dicalcium phosphate dihydrate (DCPD) cements are attractive biomaterials for bone repair, and a number of different DCPD cement formulations have been proposed in the literature. In this study we have specifically compared monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) and MCPM/?-tricalcium phosphate (?-TCP) formulations to test the hypothesis that DCPD cement chemistry affects the degradation properties and cytocompatibility of the cement. Using simple in vitro models we found that MCPM/?-TCP formulations degraded primarily by DCPD dissolution, which was associated with a slight pH drop and relatively low mass loss. Cytocompatibility testing of cement conditioned culture media revealed no significant change in cell viability relative to the negative control for all of the MCPM/?-TCP formulations. In contrast, the MCPM/HA formulations were prone to undergo rapid conversion of DCPD to HA, resulting in a sharp pH drop and extensive mass loss. A stoichiometric excess of HA in the cement was found to accelerate the conversion process, and significant cytotoxicity was observed for the MCPM/HA formulations containing excess HA. Collectively, these results show that, although the product of the setting reaction is the same, DCPD cements produced with MCPM/HA and MCPM/?-TCP formulations differ significantly in their degradation properties and cytocompatibility. These differences may have important implications for the selection of a DCPD cement formulation for clinical application. PMID:23428798

  5. Heterogeneous Glasses and Sustainable Cement

    NASA Astrophysics Data System (ADS)

    Del Gado, Emanuela

    2015-03-01

    Calcium-silicate hydrate (C-S-H) is the main binding agent in cement and concrete. It forms at the beginning of cement hydration, it progressively densifies as cement hardens and is ultimately responsible for the performances of concrete. This hydration product is a cohesive nano-scale heterogeneous glass, whose structure and mechanics are still poorly understood, in spite of its practical importance. I will review some of the open questions for this fascinating material and discuss a statistical physics approach recently developed, which allows us to investigate the structural arrest and solidification under the out-of-equilibrium conditions typical of cement hydration and the role of the nano-scale structure in C-S-H mechanics upon hardening. Our approach unveils how some distinctive features of the kinetics of cement hydration can be related to changes in the morphology of this glassy material and elucidates the role of nano-scale mechanical heterogeneities in the hardened C-S-H.

  6. Understanding the Term Gifted: Process? Product? Performance?

    ERIC Educational Resources Information Center

    Sloat, Robert S.

    1990-01-01

    A model is presented that views gifted individuals as being process oriented, creative individuals as product oriented, and talented individuals as performance oriented. Approaches to acting that differ based on elements of giftedness, creativity, talent, and combinations thereof are explored. (JDD)

  7. Sustainability Analysis for Products and Processes

    EPA Science Inventory

    Sustainability Analysis for Products and Processes Subhas K. Sikdar National Risk Management Research Laboratory United States Environmental protection Agency 26 W. M.L. King Dr. Cincinnati, OH 45237 Sikdar.subhas@epa.gov ABSTRACT Claims of both sustainable and unsu...

  8. A cross-shift study of lung function, exhaled nitric oxide and inflammatory markers in blood in Norwegian cement production workers

    PubMed Central

    Not, Hilde; Skogstad, Marit; Nordby, Karl-Christian; Eduard, Wijnand; Svendsen, Martin Veel; vsteb, Reidun; Trseid, Anne Marie Siebke; Kongerud, Johny

    2011-01-01

    Objectives To study possible effects of aerosol exposure on lung function, fractional exhaled nitric oxide (FeNO) and inflammatory markers in blood from Norwegian cement production workers across one work shift (0 to 8?h) and again 32?h after the non-exposed baseline registration. Methods 95 workers from two cement plants in Norway were included. Assessment of lung function included spirometry and gas diffusion pre- and post-shift (0 and 8?h). FeNO concentrations were measured and blood samples collected at 0, 8 and 32?h. Blood analysis included cell counts of leucocytes and mediators of inflammation. Results The median respirable aerosol level was 0.3?mg/m3 (range 0.026.2?mg/m3). FEV1, FEF2575% and DLCO decreased by 37?ml (p=0.04), 170?ml/s (p<0.001) and 0.17?mmol/min/kPa (p=0.02), respectively, across the shift. A 2?ppm reduction in FeNO between 0 and 32?h was detected (p=0.01). The number of leucocytes increased by 0.6109?cells/l (p<0.001) across the shift, while fibrinogen levels increased by 0.02?g/l (p<0.001) from 0 to 32?h. TNF-? level increased and IL-10 decreased across the shift. Baseline levels of fibrinogen were associated with the highest level of respirable dust, and increased by 0.39?g/l (95% CI 0.06 to 0.72). Conclusions We observed small cross-shift changes in lung function and inflammatory markers among cement production workers, indicating that inflammatory effects may occur at exposure levels well below 1?mg/m3. However, because the associations between these acute changes and personal exposure measurements were weak and as the long-term consequences are unknown, these findings should be tested in a follow-up study. PMID:21297153

  9. CITRIC ACID AS A SET RETARDER FOR CALCIUM ALUMINATE PHOSPHATE CEMENTS.

    SciTech Connect

    SUGAMA,T.; BROTHERS, L.E.

    2005-01-01

    Citric acid added as set retarder significantly contributed to enhancing the setting temperature and to extending the thickening time of a calcium aluminate phosphate (CaP) geothermal cement slurry consisting of calcium aluminate cement (CAC) as the base reactant and sodium polyphosphate (NaP) solution as the acid reactant. The set-retarding activity of citric acid was due to the uptake of Ca{sup 2+} ions from the CAC by carboxylic acid groups within the citric acid. This uptake led to the precipitation of a Ca-complexed carboxylate compound as a set-retarding barrier layer on the CAC grains' surfaces. However, this barrier layer was vulnerable to disintegration by the attack of free Ca{sup 2+} ions from CAC, and also to degradation at elevated temperature, thereby promoting the generation of exothermic energy from acid-base reactions between the CAC and NaP after the barrier was broken. The exothermic reaction energy that was promoted in this way minimized the loss in strength of the citric acid-retarded cement. The phase composition assembled in both retarded and non-retarded cements after autoclaving at 180 C encompassed three reaction products, hydroxyapatite (HOAp), hydrogrossular and boehmite, which are responsible for strengthening the autoclaved cement. The first two reaction products were susceptible to reactions with sulfuric acid and sodium sulfate to form crystalline bassanite scale as the corrosion product. The boehmite phase possessed a great resistance to acid and sulfate. Although the bassanite scales clinging to the cement's surfaces were the major factor governing the loss in weight, they served in protecting the cement from further acid- and sulfate-corrosion until their spallation eventually occurred. Nevertheless, the repetitive processes of HOAp and hydrogrossular {yields} bassanite {yields} spallation played an important role in extending the useful lifetime of CaP cement in a low pH environment at 180 C.

  10. Estimates of global, regional, and national annual CO{sub 2} emissions from fossil-fuel burning, hydraulic cement production, and gas flaring: 1950--1992

    SciTech Connect

    Boden, T.A.; Marland, G.; Andres, R.J.

    1995-12-01

    This document describes the compilation, content, and format of the most comprehensive C0{sub 2}-emissions database currently available. The database includes global, regional, and national annual estimates of C0{sub 2} emissions resulting from fossil-fuel burning, cement manufacturing, and gas flaring in oil fields for 1950--92 as well as the energy production, consumption, and trade data used for these estimates. The methods of Marland and Rotty (1983) are used to calculate these emission estimates. For the first time, the methods and data used to calculate CO, emissions from gas flaring are presented. This C0{sub 2}-emissions database is useful for carbon-cycle research, provides estimates of the rate at which fossil-fuel combustion has released C0{sub 2} to the atmosphere, and offers baseline estimates for those countries compiling 1990 C0{sub 2}-emissions inventories.

  11. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-10-31

    The objective of this project is to develop an improved ultra- lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  12. Optimization process of tribenzoine production as a glycerol derived product

    NASA Astrophysics Data System (ADS)

    Widayat, Abdurrakhman, Rifianto, Y.; Abdullah, Hadiyanto, Samsudin, Asep M.; Annisa, A. N.

    2015-12-01

    Tribenzoin is a derived product from glycerol that can produce from glycerol conversion via esterification process. The product can be used in the food industry, cosmetics industry, polymer industry and also can be used to improve the properties of adhesive materials and water resistance in the ink printer.In the other hand, it advantages is environmentally friendly andrenewable because it is not derived from petroleum. This paper discusses the effect of temperature and catalyst concentration for tribenzoin production. For the responses, yield and product composition were observed. Results showed that the highest yield achieved at optimal variable data processed using Central Composite Design (CCD) which is 63.64 temperature (°C), mole ratio of benzoic acidto glycerol is 3.644:1, and catalyst concentration 6.25% (wt% glycerol). Yield products produced 58.71%. FTIR analysis results showed that the samples contained the results of IR spectra wavelength 1761 cm-1 in the fingerprint region and 3165 cm-1 frequency region group. The existence of these two adjustments that fixed in the area is strong evidence that the compound is tribenzoin.

  13. 30 CFR 250.422 - When may I resume drilling after cementing?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may I resume drilling after cementing? 250... Casing and Cementing Requirements 250.422 When may I resume drilling after cementing? (a) After cementing surface, intermediate, or production casing (or liners), you may resume drilling after the...

  14. [Augmentation with PMMA cement].

    PubMed

    Khn, K-D; Hntzsch, D

    2015-09-01

    Cements based on polymethyl methacrylate (PMMA) can be used without any problem in a variety of clinical augmentations. Cement-related complications in surgical procedures involving PMMA cements, such as embolism, thermal necrosis, toxicity and hypersensitivity, are often due to other causes. Knowledge about the properties of the cement helps the user to safely employ PMMA cements in augmentations. High radio-opacity is required in vertebral body augmentations and this is provided in particular by zirconium dioxide. In vertebral body augmentations, a low benzoyl peroxide (BPO) content can considerably prolong the liquid dough phase. In augmentations with cement fillings in the region of a tumor, a high BPO content can specifically increase the peak temperature of the PMMA cement. In osteosynthetic augmentations with PMMA, necrosis is rare because heat development in the presence of metallic implants is low due to heat conduction via the implant. Larger cement fillings where there is no heat conduction via metal implants can exhibit substantially higher peak temperatures. The flow properties of PMMA cements are of particular importance for the user to allow optimum handling of PMMA cements. In patients with hypersensitivity to antibiotics, there is no need to avoid the use of PMMA as there are sufficient PMMA-based alternatives. The PMMA cements are local drug delivery systems and antibiotics, antiseptics, antimycotics and also cytostatics can be mixed with the cement. Attention must be paid to antagonistic and synergistic effects. PMID:26315391

  15. Cement analysis using d + D neutrons

    NASA Astrophysics Data System (ADS)

    Womble, Phillip C.; Paschal, Jon; Moore, Ryan

    2005-12-01

    In the cement industry, the primary concern is quality control. The earlier the cement industry can institute quality control upon their product, the more significant their savings in labor, energy and material. We are developing a prototype cement analyzer using pulsed neutrons from a d-D electronic neutron generator with the goal of ensuring quality control of cement in an on-line manner. By utilizing a low intensity d-D neutron source and a specially-designed moderator assembly, we are able to produce one of the safest neutron-based systems in the market. Also, this design includes some exciting new methods of data acquisition which may substantially reduce the final installation costs. In our proof-of-principle measurements, we were able to measure the primary components of cement (Al, Si, Ca and Fe) to limits required for the raw materials, the derived mixes and the clinkers utilizing this neutron generator.

  16. Cemented implant restoration: A technique for minimizing adverse biologic consequences.

    PubMed

    Galván, Guillermo; Kois, John C; Chaiyabutr, Yada; Kois, Dean

    2015-10-01

    The purpose of this technique was to eliminate excess cement from the implant restoration by using a 2-step cementation process. A custom acrylic resin abutment, a duplicate of the titanium abutment, is fabricated before the restoration is cemented. At cementation, cement is placed inside the restoration, which is placed onto the acrylic resin abutment outside the mouth. The majority of the excess cement from inside the restoration is expressed onto the acrylic resin abutment. The restoration is then placed on the titanium abutment inside the mouth. The result is a minimum amount of excess cement expressed intraorally. This technique minimizes the adverse biological consequences of leaving excess cement beneath implant-supported restorations. PMID:26119018

  17. Multiphase Processing of Isoprene Oxidation Products - Kinetic and Product Studies

    NASA Astrophysics Data System (ADS)

    Hoffmann, D.; Schoene, L.; Schindelka, J.; Herrmann, H.

    2010-12-01

    Isoprene represents a significant fraction of NMHC in the troposphere with recently estimated emission rates of 500-750 TgC yr-1 (1). Due to its enormous source strength, the fate of isoprene and its degradation products is important in atmospheric processes. Possible ascendancies of such oxidation processes are the regional ozone and secondary organic aerosol (SOA) formation. Some aspects of SOA formation from isoprene and its degradation products have already been studied by chamber studies (2,3). Aqueous phase oxidation processes which may occur after phase transfer of ‘early’ oxidation products are often neglected. But these processes provide a potentially important source for organic particle mass constituents such as carboxylic acids. The majority of existing aqueous phase modelling studies focus only on ‘later’ products such as methylglyoxal and oxalic acid. Yet, a recent field study reports much higher aqueous phase concentrations of some ‘earlier’ isoprene oxidation products including methacrolein (MACR) and methyl vinyl ketone (MVK) than expected (4). This indicates a possibly underestimated importance of multiphase chemical processes in the course of the isoprene oxidation as a source for the production of organic particle mass together with known ‘heterogeneous processes’ such as the direct condensation of low-volatility products from gas phase processes onto existing particle surfaces. In order to implement the isoprene multiphase chemistry in atmospheric models detailed kinetic and mechanistic studies are needed. Hence, the temperature dependence of MACR, MVK, methacrylic acid and acrylic acid exposed to NO3, SO4- and OH radicals in the aqueous phase was investigated. The measurements were performed using a laser-photolysis laser long path absorption technique. The analysis confirmed in all cases the much higher reactivity of the OH radical in comparison to SO4- and NO3 radicals. The temperature dependence is most distinct for NO3 radical reactions and weakest for those with SO4-. For the identification of oxidation products different analytical techniques were applied such as HPLC-UV, CE-UV and HPLC-MS after laser flash photolysis. All samples were analyzed offline with and without prior derivatization steps. In order to purify and enrich the samples, a solid phase extraction was performed before analysis. Mainly identified reaction products are functionalized carbonyl compounds and carboxylic acids. The kinetic and mechanistic data obtained will help to improve existing aqueous phase isoprene oxidation mechanisms. With the extended mechanism the role of multiphase processes for the formation of organic particle constituents such as carboxylic acids from the isoprene oxidation can be much better assessed in the future. (1) A. Guenther, et al. (2006). ACP, 6, 3181. (2) J. H. Kroll, et al. (2006). ES&T, 40, 1869. (3) J. D. Surratt, et al. (2007). ES&T, 41, 5363. (4) D. van Pinxteren, et al. (2005). Atmos. Environ, 39, 4305.

  18. Poly(vinyl chloride) processes and products.

    PubMed Central

    Wheeler, R N

    1981-01-01

    Poly(vinyl chloride) resins are produced by four basic processes: suspension, emulsion, bulk and solution polymerization. PVC suspensions resins are usually relatively dust-free and granular with varying degrees of particle porosity. PVC emulsion resins are small particle powders containing very little free monomer. Bulk PVC resins are similar to suspension PVC resins, though the particles tend to be more porous. Solution PVC resins are smaller in particle size than suspension PVC with high porosity particles containing essentially no free monomer. The variety of PVC resin products does not lend itself to broad generalizations concerning health hazards. In studying occupational hazards the particular PVC process and the product must be considered and identified in the study. PMID:7333230

  19. Multiphase Flow Modeling of Biofuel Production Processes

    SciTech Connect

    D. Gaston; D. P. Guillen; J. Tester

    2011-06-01

    As part of the Idaho National Laboratory's (INL's) Secure Energy Initiative, the INL is performing research in areas that are vital to ensuring clean, secure energy supplies for the future. The INL Hybrid Energy Systems Testing (HYTEST) Laboratory is being established to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. HYTEST involves producing liquid fuels in a Hybrid Energy System (HES) by integrating carbon-based (i.e., bio-mass, oil-shale, etc.) with non-carbon based energy sources (i.e., wind energy, hydro, geothermal, nuclear, etc.). Advances in process development, control and modeling are the unifying vision for HES. This paper describes new modeling tools and methodologies to simulate advanced energy processes. Needs are emerging that require advanced computational modeling of multiphase reacting systems in the energy arena, driven by the 2007 Energy Independence and Security Act, which requires production of 36 billion gal/yr of biofuels by 2022, with 21 billion gal of this as advanced biofuels. Advanced biofuels derived from microalgal biomass have the potential to help achieve the 21 billion gal mandate, as well as reduce greenhouse gas emissions. Production of biofuels from microalgae is receiving considerable interest due to their potentially high oil yields (around 600 gal/acre). Microalgae have a high lipid content (up to 50%) and grow 10 to 100 times faster than terrestrial plants. The use of environmentally friendly alternatives to solvents and reagents commonly employed in reaction and phase separation processes is being explored. This is accomplished through the use of hydrothermal technologies, which are chemical and physical transformations in high-temperature (200-600 C), high-pressure (5-40 MPa) liquid or supercritical water. Figure 1 shows a simplified diagram of the production of biofuels from algae. Hydrothermal processing has significant advantages over other biomass processing methods with respect to separations. These 'green' alternatives employ a hybrid medium that, when operated supercritically, offers the prospect of tunable physicochemical properties. Solubility can be rapidly altered and phases partitioned selectively to precipitate or dissolve certain components by altering temperature or pressure in the near-critical region. The ability to tune the solvation properties of water in the highly compressible near-critical region facilitates partitioning of products or by-products into separate phases to separate and purify products. Since most challenges related to lipid extraction are associated with the industrial scale-up of integrated extraction systems, the new modeling capability offers the prospect of addressing previously untenable scaling issues.

  20. Current Status of Geothermal Well Cement Development

    SciTech Connect

    Kukacka, L. E.

    1981-01-01

    The results of a study made in 1976 indicated that the cements used for well completion deteriorate in the geothermal environments and that the life expectancy of a well, and therefore the economics of geothermal processes, could be improved significantly if better materials were developed. On the basis of this assessment, Brookhaven National Laboratory (BNL) helped the Department of Energy, Division of Geothermal Energy to organize a program to develop materials that meet the estimated design criteria for geothermal well cements. The BNL work involves research on polymer cements and full management of an integrated program involving contract research and industrial participation. The program consists of the following phases: (1) problem definition, (2) cement research and development, (3) property verification, (4) downhole testing, and (5) cementing of demonstration wells.

  1. Principles and applications of cement slurries

    SciTech Connect

    Guillot, D.; Baret, J.F.

    1996-12-31

    The basic principles of oil well cementing are first described together with the main critical engineering constraints encountered during a primary cementing operation, that is, wellbore control, mud displacement, fluid loss control, and gas migration. Then cement slurry properties that are relevant to the process are reviewed and the procedures used to measure these properties are discussed. Particular attention is given to rheological measurements that call be affected by wall slip when losing coaxial cylinder or pipe flow viscometers. This is followed by an overview of the additives that are used to obtained the required cement slurry or set cement properties, like weighting agents/extenders, retarders, dispersants, fluid loss agents, and antisettling agents. Some typical mechanisms of action of these additives are briefly discussed. 30 refs., 23 figs., 2 tabs.

  2. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  3. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-10-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, a comparison study of the three cement systems examined the effect that cement drillout has on the three cement systems. Testing to determine the effect of pressure cycling on the shear bond properties of the cement systems was also conducted. This report discusses testing that will be performed for analyzing the alkali-silica reactivity of ULHS in cement slurries, as well as the results of Field Tests 1 and 2.

  4. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-07-18

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job.

  5. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-04-29

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems, including foamed and sodium silicate slurries. During this project quarter, comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, and shear bond. Testing to determine the effect of temperature cycling on the shear bond properties of the cement systems was also conducted. In addition, the stress-strain behavior of the cement types was studied. This report discusses a software program that is being developed to help design ULHS cements and foamed cements.

  6. Amphoteric surfactants: processing, product composition and properties.

    PubMed

    Leidreiter, H I; Gruning, B; Kaseborn, D

    1997-10-01

    Cocamidopropyl betaine (CAPB) has been the most important secondary surfactant for personal-cleansing products for a long time. Its excellent toxicological profile is an important reason for its increasing use in oral-care products. Recently it has gained interest for further applications such as household cleaners, dish-washing liquids, and industrial and technical products. Imidazoline-derived amphoterics such as sodium cocoampho-acetate (SCAA) or diacetate play a more minor role than CAPB. Owing to the low irritation potential of the pure surfactant and its good toxicological properties, ampho-acetates have mainly found applications in cosmetics. Their industrial applications have been relatively small. While CAPB has a well-defined chemical structure from a straightforward production process, most imidazoline-derived amphoterics exhibit a complex composition of compounds with different structures. This depends on the production parameters. Improved processing methods have recently led to the commercial availability of well-defined SCAA with low levels of by-products. Modern production processes and the composition of high-purity amphoterics are reviewed. Raw materials and by-products are described, together with their analytical methods. The cosmetic performance, cleansing and foaming power, rheological effects and mildness-enhancing properties of both CAPB and SCAA are compared. La cocamidopropyl-betaine (CAPB) est, depuis longtemps le tensio-actif secondaire le plus important pour les produits d'hygiene personnelle. L'excellent profil toxicologique de la CAPB est certainement une raison majeure de son usage croissant dans les produits de soin buccaux. La CAPB a suscite depuis peu un interet pour des applications supplementaires telles que les nettoyants menagers, les liquides vaisselle, les produits industriels et techniques. Les derives amphoteres de l'imidazoline tels que le cocoampho-acetate de sodium (SCAA) ou le diacetate occupent une place mineure comparee a la CAPB. En raison du faible potentiel irritant du tensio-actif pur et meme de bonne proprietes toxicologiques, les ampho-acetates trouvent principalement leurs applications dans les cosmetiqes. Leur role dans les applications industrielles est relativement limite. Alors que la CAPB a une structure chimique bien definie a partir d'un procede de production direct, la plupart des derives amphoteres d'imidazoline presentent une composition complexe de composes aux structures differentes. Ceci depend des parametres de production. Des procedes de production ameliores ont recemment conduit a une disponibilite commerciale de SCAA bien definis avec de faibles teneurs en produits secondaires. Les procedes modernes de production et la composition d'amphoteres de grande purete sont decrits. Les matieres premieres et les produits secondaires sont decrits ainsi que leurs methodes d'analyse. Le comportement cosmetique, le pouvoir nettoyant et moussant, les effets rheologiques et les proprietes adoucissantes sont compares, a la fois pour la CAPB et le SCAA. PMID:18507630

  7. The suitability of a supersulfated cement for nuclear waste immobilisation

    NASA Astrophysics Data System (ADS)

    Collier, N. C.; Milestone, N. B.; Gordon, L. E.; Ko, S.-C.

    2014-09-01

    Composite cements based on ordinary Portland cement are used in the UK as immobilisation matrices for low and intermediate level nuclear wastes. However, the high pore solution pH causes corrosion of some metallic wastes and undesirable expansive reactions, which has led to alternative cementing systems being examined. We have investigated the physical, chemical and microstructural properties of a supersulfated cement in order to determine its applicability for use in nuclear waste encapsulation. The hardened supersulfated cement paste appeared to have properties desirable for use in producing encapsulation matrices, but the high powder specific surface resulted in a matrix with high porosity. Ettringite and calcium silicate hydrate were the main phases formed in the hardened cement paste and anhydrite was present in excess. The maximum rate of heat output during hydration of the supersulfated cement paste was slightly higher than that of a 9:1 blastfurnace slag:ordinary Portland cement paste commonly used by the UK nuclear waste processing industry, although the total heat output of the supersulfated cement paste was lower. The pH was also significantly lower in the supersulfated cement paste. Aluminium hydroxide was formed on the surface of aluminium metal encapsulated in the cement paste and ettringite was detected between the aluminium hydroxide and the hardened cement paste.

  8. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, T.

    1993-09-21

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120 C to about 300 C to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate. 10 figures.

  9. Phosphate-bonded calcium aluminate cements

    DOEpatents

    Sugama, Toshifumi (Mastic Beach, NY)

    1993-01-01

    A method is described for making a rapid-setting phosphate-bonded cementitious material. A powdered aluminous cement is mixed with an aqueous solution of ammonium phosphate. The mixture is allowed to set to form an amorphous cementitious material which also may be hydrothermally treated at a temperature of from about 120.degree. C. to about 300.degree. C. to form a crystal-containing phosphate-bonded material. Also described are the cementitious products of this method and the cement composition which includes aluminous cement and ammonium polyphosphate.

  10. In situ vitrification: Process and products

    SciTech Connect

    Kindle, C.; Koegler, S.

    1991-06-01

    In situ vitrification (ISV) is an electrically powered thermal treatment process that converts soil into a chemically inert and stable glass and crystalline product. It is similar in concept to bringing a simplified glass manufacturing process to a site and operating it in the ground, using the soil as a glass feed stock. Gaseous emissions are contained, scrubbed, and filtered. When the process is completed, the molten volume cools producing a block of glass and crystalline material that resembles natural obsidian commingled with crystalline phases. The product passes US Environmental Protection Agency (EPA) leach resistance tests, and it can be classified as nonhazardous from a chemical hazard perspective. ISV was developed by the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) for application to contaminated soils. It is also being adapted for applications to buried waste, underground tanks, and liquid seepage sites. ISV's then-year development period has included tests on many different site conditions. As of January 1991 there have been 74 tests using PNL's ISV equipment; these tests have ranged from technology development tests using nonhazardous conditions to hazardous and radioactive tests. 2 refs., 6 figs., 7 tabs.

  11. Literature survey on cements for remediation of deformed casing in geothermal wells

    SciTech Connect

    Allan, M.L.; Philippacopoulos, A.J.

    1998-12-31

    Brookhaven National Laboratory was requested to conduct a literature survey for the best available cement to use in the proposed casing patch as part of the Geothermal Drilling Organization (GDO) project on remediation of deformed casings. A total of 50 wells have been identified with deformed production casing in Unocal`s portion of The Geysers geothermal field. A procedure to address the casing deformation and avoid abandonment of these wells has been developed as described in the Geysers Deformed Casing Remediation Proposal. The proposed remediation procedure involves isolation of the zone of interest with an inflatable packer, milling the deformed casing and cementing a 7 inch diameter liner to extend approximately 100 ft above and 100 ft below the milled zone. During the milling operation it is possible that the original cement and surrounding formation may slough away. In order to specify a suitable cement formulation for the casing patch it is first necessary to identify and understand the deformation mechanism/s operating in The Geysers field. Subsequently, the required cement mechanical properties to withstand further deformation of the repaired system must be defined. From this information it can be determined whether available cement formulations meet these requirements. In addition to The Geysers, other geothermal fields are at possible risk of casing deformation due to subsidence, seismic activity, lateral and vertical formation movement or other processes. Therefore, the proposed remediation procedure may have applications in other fields.

  12. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-01-15

    The objective of this project is to develop an improved ultra-lightweigh cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems, Task 2: Review Russian Ultra-Lightweight Cement Literature, and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary surface pipe and intermediate casing cementing conditions historically encountered in the US and establishment of average design conditions for ULHS cements. Russian literature concerning development and use of ultra-lightweight cements employing either nitrogen or ULHS was reviewed, and a summary is presented. Quality control testing of materials used to formulate ULHS cements in the laboratory was conducted to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS. This protocol is presented and discussed. finally, results of initial testing of ULHS cements is presented along with analysis to establish cement performance design criteria to be used during the remainder of the project.

  13. Power Ultrasound to Process Dairy Products

    NASA Astrophysics Data System (ADS)

    Bermúdez-Aguirre, Daniela; Barbosa-Cánovas, Gustavo V.

    Conventional methods of pasteurizing milk involve the use of heat regardless of treatment (batch, high temperature short time - HTST or ultra high temperature - UHT sterilization), and the quality of the milk is affected because of the use of high temperatures. Consequences of thermal treatment are a decrease in nutritional properties through the destruction of vitamins or denaturation of proteins, and sometimes the flavor of milk is undesirably changed. These changes are produced at the same time that the goal of the pasteurization process is achieved, which is to have a microbiological safe product, free of pathogenic bacteria, and to reduce the load of deteriorative microorganisms and enzymes, resulting in a product with a longer storage life.

  14. Distribution of Hg, As and Se in material and flue gas streams from preheater-precalciner cement kilns and vertical shaft cement kilns in China.

    PubMed

    Yan, Dahai; Peng, Zheng; Ding, Qiong; Karstensen, Kre Helge; Engelsen, Christian J; Li, Li; Ren, Yong; Jiang, Chen

    2015-08-01

    The aim of this study was to evaluate the behavior of Hg, As, and Se in cement production. Two types of cement plants were studied, including the vertical shaft kiln (VSK) and preheater-precalciner kiln (PPK) processes. Determination of Hg, As, and Se in the main material and gas streams were performed. It was found that recycling of particulate matter captured by an air pollution control device caused a significant enrichment of Hg and As inside both processes. The total quantity of Hg entering the process and the quantity emitted to the atmosphere were found to be 10-109 and 6.3-38 mg, respectively, per ton of clinker produced. The average Hg emission was calculated to be around 41% of the total mercury input. The emissions found complied with the European Union (EU) limit and exceeded partly the U.S. limit. Furthermore, it was found that oxidized mercury was the dominant species in the PPK process, whereas the reduced form was dominant in the VSK process, due to the oxidizing and reducing gas conditions, respectively. Regarding the distribution of As and Se, the major amounts were bound to the solid materials, that is, cement clinker and particulate matter. Based on cement production data in China in 2013, the annual emissions of Hg and As were estimated to be in the range of 8.6-52 and 4.1-9.5 tons, respectively. PMID:26037967

  15. Entropy production in irreversible processes with friction.

    PubMed

    Bizarro, Joo P S

    2008-08-01

    Established expressions for entropy production in irreversible processes are generalized to include friction explicitly, as a source of irreversibility in the interaction between a system and its surroundings. The net amount of heat delivered to the system does not come now only from the reservoir, but may have an additional component coming from the work done against friction forces and dissipated as heat. To avoid ambiguities in interpreting the different contributions to entropy increase, the latter is also written in terms of the heat directly exchanged between the system and surroundings and of the fraction of frictional work that is lost in the system. PMID:18850816

  16. Optical evaluation on the setting of cement paste

    NASA Astrophysics Data System (ADS)

    De Len Martnez, H. A.; Bernal, J. J. Soto; Gonzlez Mota, R.; Rosales-Candelas, I.

    2015-01-01

    In the construction area, one of the most widely used cement is the CPC 30R, it is a hydraulic binder consisting of CaO, SiO2, Al2O3 and Fe2O3, when mixed with water forms cement pastes and its four crystallographic phases start to hydrate. The diffuse reflection on cement paste can give an indication of the behaviour on optical properties on the hydration of the cement and early formation products. In this study, Portland cement (CPC) pastes were prepared with 0.45 a water to cement ratio (w/c). This work is aimed to evaluate the optical properties of cement pastes on the hydration reaction during the first 24 hours by measuring the intensity of diffuse reflection changes.

  17. Process for production of a metal hydride

    DOEpatents

    Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

    2014-08-12

    A process for production of a metal hydride compound MH.sub.x, wherein x is one or two and M is an alkali metal, Be or Mg. The process comprises combining a compound of formula (R.sup.1O).sub.xM with aluminum, hydrogen and at least one metal selected from among titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula MH.sub.x. R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group. A mole ratio of aluminum to (R.sup.1O).sub.xM is from 0.1:1 to 1:1. The catalyst is present at a level of at least 200 ppm based on weight of aluminum.

  18. Horizontal wells pose cementing challenges

    SciTech Connect

    1996-07-01

    Successful cementing of horizontal wells depends on many factors such as drilling fluid properties, casing centralization, displacement mechanics, cement-mud spacer design and cement slurry properties. Finally, proper evaluation is essential to determine the success or failure of a horizontal casing cement job. The paper discusses displacement mechanics of the drilling fluid and cuttings and cement rheology.

  19. Development of an Improved Cement for Geothermal Wells

    SciTech Connect

    Trabits, George

    2015-04-20

    After an oil, gas, or geothermal production well has been drilled, the well must be stabilized with a casing (sections of steel pipe that are joined together) in order to prevent the walls of the well from collapsing. The gap between the casing and the walls of the well is filled with cement, which locks the casing into place. The casing and cementing of geothermal wells is complicated by the harsh conditions of high temperature, high pressure, and a chemical environment (brines with high concentrations of carbon dioxide and sulfuric acid) that degrades conventional Portland cement. During the 1990s and early 2000s, the U.S. Department of Energy’s Geothermal Technologies Office (GTO) provided support for the development of fly-ash-modified calcium aluminate phosphate (CaP) cement, which offers improved resistance to degradation compared with conventional cement. However, the use of CaP cements involves some operational constraints that can increase the cost and complexity of well cementing. In some cases, CaP cements are incompatible with chemical additives that are commonly used to adjust cement setting time. Care must also be taken to ensure that CaP cements do not become contaminated with leftover conventional cement in pumping equipment used in conventional well cementing. With assistance from GTO, Trabits Group, LLC has developed a zeolite-containing cement that performs well in harsh geothermal conditions (thermal stability at temperatures of up to 300°C and resistance to carbonation) and is easy to use (can be easily adjusted with additives and eliminates the need to “sterilize” pumping equipment as with CaP cements). This combination of properties reduces the complexity/cost of well cementing, which will help enable the widespread development of geothermal energy in the United States.

  20. INVESTIGATION OF THE FORMATION OF A PORTLAND CEMENT PLANT DETACHED PLUME

    EPA Science Inventory

    A gaseous and particulate source emissions sampling program has been conducted at a Portland Cement production plant in Rapid City South Dakota. The study was conducted to determine the cause of the formation of an opaque detached plume from the plants' dry process kiln. The inst...

  1. Microbial production of scleroglucan and downstream processing

    PubMed Central

    Castillo, Natalia A.; Valdez, Alejandra L.; Fariña, Julia I.

    2015-01-01

    Synthetic petroleum-based polymers and natural plant polymers have the disadvantage of restricted sources, in addition to the non-biodegradability of the former ones. In contrast, eco-sustainable microbial polysaccharides, of low-cost and standardized production, represent an alternative to address this situation. With a strong global market, they attracted worldwide attention because of their novel and unique physico-chemical properties as well as varied industrial applications, and many of them are promptly becoming economically competitive. Scleroglucan, a β-1,3-β-1,6-glucan secreted by Sclerotium fungi, exhibits high potential for commercialization and may show different branching frequency, side-chain length, and/or molecular weight depending on the producing strain or culture conditions. Water-solubility, viscosifying ability and wide stability over temperature, pH and salinity make scleroglucan useful for different biotechnological (enhanced oil recovery, food additives, drug delivery, cosmetic and pharmaceutical products, biocompatible materials, etc.), and biomedical (immunoceutical, antitumor, etc.) applications. It can be copiously produced at bioreactor scale under standardized conditions, where a high exopolysaccharide concentration normally governs the process optimization. Operative and nutritional conditions, as well as the incidence of scleroglucan downstream processing will be discussed in this chapter. The relevance of using standardized inocula from selected strains and experiences concerning the intricate scleroglucan scaling-up will be also herein outlined. PMID:26528259

  2. Microbial production of scleroglucan and downstream processing.

    PubMed

    Castillo, Natalia A; Valdez, Alejandra L; Faria, Julia I

    2015-01-01

    Synthetic petroleum-based polymers and natural plant polymers have the disadvantage of restricted sources, in addition to the non-biodegradability of the former ones. In contrast, eco-sustainable microbial polysaccharides, of low-cost and standardized production, represent an alternative to address this situation. With a strong global market, they attracted worldwide attention because of their novel and unique physico-chemical properties as well as varied industrial applications, and many of them are promptly becoming economically competitive. Scleroglucan, a ?-1,3-?-1,6-glucan secreted by Sclerotium fungi, exhibits high potential for commercialization and may show different branching frequency, side-chain length, and/or molecular weight depending on the producing strain or culture conditions. Water-solubility, viscosifying ability and wide stability over temperature, pH and salinity make scleroglucan useful for different biotechnological (enhanced oil recovery, food additives, drug delivery, cosmetic and pharmaceutical products, biocompatible materials, etc.), and biomedical (immunoceutical, antitumor, etc.) applications. It can be copiously produced at bioreactor scale under standardized conditions, where a high exopolysaccharide concentration normally governs the process optimization. Operative and nutritional conditions, as well as the incidence of scleroglucan downstream processing will be discussed in this chapter. The relevance of using standardized inocula from selected strains and experiences concerning the intricate scleroglucan scaling-up will be also herein outlined. PMID:26528259

  3. Flavor violating processes with sgoldstino pair production

    NASA Astrophysics Data System (ADS)

    Demidov, S. V.; Gorbunov, D. S.

    2012-04-01

    In supersymmetric extensions of the standard model of particle physics (SM), goldstino superpartnersscalar and pseudoscalar sgoldstinoscan be light enough for emerging in decays of SM particles. Sgoldstino interaction with SM fields is suppressed by the scale of supersymmetry breaking in the whole theory. Hence, searches for sgoldstinos give an opportunity to probe the underlying mechanism of supersymmetry breaking. Sgoldstino couplings to SM fields are proportional to the supersymmetry breaking parametersMSSM soft termsand therefore can lead to flavor violating processes in quark and lepton sectors. We consider flavor violating processes involving sgoldstino pair production which are driven by sgoldstino couplings proportional to squark and slepton soft mass terms, mLL2 and mRR2. We find that present limits on off-diagonal entries in squark and slepton squared mass matrices allow t-, b-, c-quark and ?-lepton decays at levels available for study with existing data (BaBar, Belle, CLEOc) and in ongoing experiments (LHCb, CMS, ATLAS). In particular, we obtain the following branching ratios Br(t?cSP)?10-7, Br(???SP)?10-7, Br(Bs?SP)?10-4, Br(B?K(*)SP)?10-4, Br(D?SP)?10-7 with sgoldstino subsequent decays into kinematically allowed pairs of SM particles ??, e+e-, ?+?-, etc. Remarkably, the prominent signature of sgoldstino pair production is two muon pairs with pair momenta peaked at sgoldstino masses.

  4. Sequential processing during noun phrase production.

    PubMed

    Bürki, Audrey; Sadat, Jasmin; Dubarry, Anne-Sophie; Alario, F-Xavier

    2016-01-01

    This study examined whether the brain operations involved during the processing of successive words in multi word noun phrase production take place sequentially or simultaneously. German speakers named pictures while ignoring a written distractor superimposed on the picture (picture-word interference paradigm) using the definite determiner and corresponding German noun. The gender congruency and the phonological congruency (i.e., overlap in first phonemes) between target and distractor were manipulated. Naming responses and EEG were recorded. The behavioural performance replicated both the phonology and the gender congruency effects (i.e., shorter naming latencies for gender congruent than incongruent and for phonologically congruent than incongruent trials). The phonological and gender manipulations also influenced the EEG data. Crucially, the two effects occurred in different time windows and over different sets of electrodes. The phonological effect was observed substantially earlier than the gender congruency effect. This finding suggests that the processing of determiners and nouns during determiner noun phrase production occurs at least partly sequentially. PMID:26407338

  5. The contemporary cement cycle of the United States

    USGS Publications Warehouse

    Kapur, A.; Van Oss, H. G.; Keoleian, G.; Kesler, S.E.; Kendall, A.

    2009-01-01

    A country-level stock and flow model for cement, an important construction material, was developed based on a material flow analysis framework. Using this model, the contemporary cement cycle of the United States was constructed by analyzing production, import, and export data for different stages of the cement cycle. The United States currently supplies approximately 80% of its cement consumption through domestic production and the rest is imported. The average annual net addition of in-use new cement stock over the period 2000-2004 was approximately 83 million metric tons and amounts to 2.3 tons per capita of concrete. Nonfuel carbon dioxide emissions (42 million metric tons per year) from the calcination phase of cement manufacture account for 62% of the total 68 million tons per year of cement production residues. The end-of-life cement discards are estimated to be 33 million metric tons per year, of which between 30% and 80% is recycled. A significant portion of the infrastructure in the United States is reaching the end of its useful life and will need to be replaced or rehabilitated; this could require far more cement than might be expected from economic forecasts of demand for cement. ?? 2009 Springer Japan.

  6. Pinellas Plant facts. [Products, processes, laboratory facilities

    SciTech Connect

    Not Available

    1986-09-01

    This plant was built in 1956 in response to a need for the manufacture of neutron generators, a principal component in nuclear weapons. The neutron generators consist of a miniaturized linear ion accelerator assembled with the pulsed electrical power supplies required for its operation. The ion accelerator, or neutron tube, requires ultra clean, high vacuum technology: hermetic seals between glass, ceramic, glass-ceramic, and metal materials: plus high voltage generation and measurement technology. The existence of these capabilities at the Pinellas Plant has led directly to the assignment of the lightning arrester connector, specialty capacitor, vacuum switch, and crystal resonator. Active and reserve batteries and the radioisotopically-powered thermoelectric generator draw on the materials measurement and controls technologies which are required to ensure neutron generator life. A product development and production capability in alumina ceramics, cermet (electrical) feedthroughs, and glass ceramics has become a specialty of the plant; the laboratories monitor the materials and processes used by the plant's commercial suppliers of ferroelectric ceramics. In addition to the manufacturing facility, a production development capability is maintained at the Pinellas Plant.

  7. Downstream Processing of Synechocystis for Biofuel Production

    NASA Astrophysics Data System (ADS)

    Sheng, Jie

    Lipids and free fatty acids (FFA) from cyanobacterium Synechocystis can be used for biofuel (e.g. biodiesel or renewable diesel) production. In order to utilize and scale up this technique, downstream processes including culturing and harvest, cell disruption, and extraction were studied. Several solvents/solvent systems were screened for lipid extraction from Synechocystis. Chloroform + methanol-based Folch and Bligh & Dyer methods were proved to be "gold standard" for small-scale analysis due to their highest lipid recoveries that were confirmed by their penetration of the cell membranes, higher polarity, and stronger interaction with hydrogen bonds. Less toxic solvents, such as methanol and MTBE, or direct transesterification of biomass (without preextraction step) gave only slightly lower lipid-extraction yields and can be considered for large-scale application. Sustained exposure to high and low temperature extremes severely lowered the biomass and lipid productivity. Temperature stress also triggered changes of lipid quality such as the degree of unsaturation; thus, it affected the productivities and quality of Synechocystis-derived biofuel. Pulsed electric field (PEF) was evaluated for cell disruption prior to lipid extraction. A treatment intensity > 35 kWh/m3 caused significant damage to the plasma membrane, cell wall, and thylakoid membrane, and it even led to complete disruption of some cells into fragments. Treatment by PEF enhanced the potential for the low-toxicity solvent isopropanol to access lipid molecules during subsequent solvent extraction, leading to lower usage of isopropanol for the same extraction efficiency. Other cell-disruption methods also were tested. Distinct disruption effects to the cell envelope, plasma membrane, and thylakoid membranes were observed that were related to extraction efficiency. Microwave and ultrasound had significant enhancement of lipid extraction. Autoclaving, ultrasound, and French press caused significant release of lipid into the medium, which may increase solvent usage and make medium recycling difficult. Production of excreted FFA by mutant Synechocystis has the potential of reducing the complexity of downstream processing. Major problems, such as FFA precipitation and biodegradation by scavengers, account for FFA loss in operation. Even a low concentration of FFA scavengers could consume FFA at a high rate that outpaced FFA production rate. Potential strategies to overcome FFA loss include high pH, adsorptive resin, and sterilization techniques.

  8. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-01-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. DOE joined the Materials Management Service (MMS)-sponsored joint industry project ''Long-Term Integrity of Deepwater Cement under Stress/Compaction Conditions.'' Results of the project contained in two progress reports are also presented in this report.

  9. Cascaded processing in written compound word production

    PubMed Central

    Bertram, Raymond; Tønnessen, Finn Egil; Strömqvist, Sven; Hyönä, Jukka; Niemi, Pekka

    2015-01-01

    In this study we investigated the intricate interplay between central linguistic processing and peripheral motor processes during typewriting. Participants had to typewrite two-constituent (noun-noun) Finnish compounds in response to picture presentation while their typing behavior was registered. As dependent measures we used writing onset time to assess what processes were completed before writing and inter-key intervals to assess what processes were going on during writing. It was found that writing onset time was determined by whole word frequency rather than constituent frequencies, indicating that compound words are retrieved as whole orthographic units before writing is initiated. In addition, we found that the length of the first syllable also affects writing onset time, indicating that the first syllable is fully prepared before writing commences. The inter-key interval results showed that linguistic planning is not fully ready before writing, but cascades into the motor execution phase. More specifically, inter-key intervals were largest at syllable and morpheme boundaries, supporting the view that additional linguistic planning takes place at these boundaries. Bigram and trigram frequency also affected inter-key intervals with shorter intervals corresponding to higher frequencies. This can be explained by stronger memory traces for frequently co-occurring letter sequences in the motor memory for typewriting. These frequency effects were even larger in the second than in the first constituent, indicating that low-level motor memory starts to become more important during the course of writing compound words. We discuss our results in the light of current models of morphological processing and written word production. PMID:25954182

  10. Comparative assessment of TRU waste forms and processes. Volume I. Waste form and process evaluations

    SciTech Connect

    Ross, W.A.; Lokken, R.O.; May, R.P.; Roberts, F.P.; Timmerman, C.L.; Treat, R.L.; Westsik, J.H. Jr.

    1982-09-01

    This study provides an assesses seven waste forms and eight processes for immobilizing transuranic (TRU) wastes. The waste forms considered are cast cement, cold-pressed cement, FUETAP (formed under elevated temperature and pressure) cement, borosilicate glass, aluminosilicate glass, basalt glass-ceramic, and cold-pressed and sintered silicate ceramic. The waste-immobilization processes considered are in-can glass melting, joule-heated glass melting, glass marble forming, cement casting, cement cold-pressing, FUETAP cement processing, ceramic cold-pressing and sintering, basalt glass-ceramic processing. Properties considered included gas generation, chemical durability, mechanical strength, thermal stability, and radiation stability. The ceramic products demonstrated the best properties, except for plutonium release during leaching. The glass and ceramic products had similar properties. The cement products generally had poorer properties than the other forms, except for plutonium release during leaching. Calculations of the Pu release indicated that the waste forms met the proposed NRC release rate limit of 1 part in 10/sup 5/ per year in most test conditions. The cast-cement process had the lowest processing cost, followed closely by the cold-pressed and FUETAP cement processes. Joule-heated glass melting had the lower cost of the glass processes. In-can melting in a high-quality canister had the highest cost, and cold-pressed and sintered ceramic the second highest. Labor and canister costs for in-can melting were identified. The major contributor to costs of disposing of TRU wastes in a defense waste repository is waste processing costs. Repository costs could become the dominant cost for disposing of TRU wastes in a commercial repository. It is recommended that cast and FUETAP cement and borosilicate glass waste-form systems be considered. 13 figures, 16 tables.

  11. Determining the water-cement ratio, cement content, water content and degree of hydration of hardened cement paste: Method development and validation on paste samples

    SciTech Connect

    Wong, H.S. Buenfeld, N.R.

    2009-10-15

    We propose a new method to estimate the initial cement content, water content and free water/cement ratio (w/c) of hardened cement-based materials made with Portland cements that have unknown mixture proportions and degree of hydration. This method first quantifies the composition of the hardened cement paste, i.e. the volumetric fractions of capillary pores, hydration products and unreacted cement, using high-resolution field emission scanning electron microscopy (FE-SEM) in the backscattered electron (BSE) mode and image analysis. From the obtained data and the volumetric increase of solids during cement hydration, we compute the initial free water content and cement content, hence the free w/c ratio. The same method can also be used to calculate the degree of hydration. The proposed method has the advantage that it is quantitative and does not require comparison with calibration graphs or reference samples made with the same materials and cured to the same degree of hydration as the tested sample. This paper reports the development, assumptions and limitations of the proposed method, and preliminary results from Portland cement pastes with a range of w/c ratios (0.25-0.50) and curing ages (3-90 days). We also discuss the extension of the technique to mortars and concretes, and samples made with blended cements.

  12. Mesoscale texture of cement hydrates

    PubMed Central

    Ioannidou, Katerina; Krakowiak, Konrad J.; Bauchy, Mathieu; Hoover, Christian G.; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J.-M.; Del Gado, Emanuela

    2016-01-01

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium–silicate–hydrates (C–S–H) during cement hydration. Controlling structure and properties of the C–S–H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C–S–H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C–S–H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C–S–H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C–S–H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  13. Mesoscale texture of cement hydrates.

    PubMed

    Ioannidou, Katerina; Krakowiak, Konrad J; Bauchy, Mathieu; Hoover, Christian G; Masoero, Enrico; Yip, Sidney; Ulm, Franz-Josef; Levitz, Pierre; Pellenq, Roland J-M; Del Gado, Emanuela

    2016-02-23

    Strength and other mechanical properties of cement and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Controlling structure and properties of the C-S-H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C-S-H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C-S-H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C-S-H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C-S-H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials. PMID:26858450

  14. 21 CFR 820.70 - Production and process controls.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Production and Process Controls § 820.70 Production and process... product quality, the manufacturer shall establish and maintain procedures to adequately control these... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Production and process controls. 820.70...

  15. 21 CFR 820.70 - Production and process controls.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Production and Process Controls § 820.70 Production and process... product quality, the manufacturer shall establish and maintain procedures to adequately control these... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Production and process controls. 820.70...

  16. 21 CFR 820.70 - Production and process controls.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Production and Process Controls § 820.70 Production and process... product quality, the manufacturer shall establish and maintain procedures to adequately control these... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Production and process controls. 820.70...

  17. Reducing CO2-Emission by using Eco-Cements

    NASA Astrophysics Data System (ADS)

    Voit, K.; Bergmeister, K.; Janotka, I.

    2012-04-01

    CO2 concentration in the air is rising constantly. Globally, cement companies are emitting nearly two billion tonnes/year of CO2 (or around 6 to 7 % of the planet's total CO2 emissions) by producing portland cement clinker. At this pace, by 2025 the cement industry will be emitting CO2 at a rate of 3.5 billion tones/year causing enormous environmental damage (Shi et al., 2011; Janotka et al., 2012). At the dawn of the industrial revolution in the mid-eighteenth century the concentration of CO2 was at a level of ca. 280 ppm. 200 years later at the time of World War II the CO2 level had risen to 310 ppm what results in a rate of increase of 0,15 ppm per year for that period (Shi et al., 2011). In November 2011 the CO2 concentration reached a value of 391 ppm (NOAA Earth System Research Laboratory, 2011), a rise of ca. 81 ppm in 66 years and an increased rate of around 1,2 ppm/year respectively. In the same period cement production in tons of cement has multiplied by a factor of ca. 62 (Kelly & Oss, US Geological Survey, 2010). Thus new CO2-saving eco-cement types are gaining in importance. In these cement types the energy-consuming portland cement clinker is partially replaced by latent hydraulic additives such as blast furnace slag, fly ash or zeolite. These hydraulic additives do not need to be fired in the rotary furnace. They ony need to be pulverized to the required grain size and added to the ground portland cement clinker. Hence energy is saved by skipping the engery-consuming firing process, in addition there is no CO2-degassing as there is in the case of lime burning. Therefore a research project between Austria and Slovakia, funded by the EU (Project ENVIZEO), was initiated in 2010. The main goal of this project is to develop new CEM V eco-types of cements and certificate them for common usage. CEM V is a portland clinker saving cement kind that allows the reduction of clinker to a proportion of 40-64% for CEM V/A and 20-39% for CEM V/B respectively by the input of slag sands, puzzolanes and fly ash (according to standard EN 197-1). In this context four new CEM V kinds have been created, two Austrian types based on slag and fly ash, and two Slovak types, one based on slag and fly ash, the other on slag and natural pozzolana. The pozzolana consist of zeolite of clinoptilolite type that is gained from a Slovak deposit.

  18. Process, optimized acidizing reduce production facility upsets

    SciTech Connect

    Ali, S.A.; Hill, D.G.; McConnell, S.B.; Johnson, M.R.

    1997-02-10

    The filtration/absorption process, coupled with optimum treatments, prevent facility upsets that increase the time and resources required for bringing a well back on-line following an acid stimulation. Surface active agents, required in acidizing to improve well productivity, can form oil/water emulsions and cause unacceptable oil and grease levels during acid flowback. But recent offshore experiences after acidizing show that operators can achieve oil and grease discharge limits without facility upsets. To minimize oil and grease, the additives need to be optimized by adding a mutual breakout solvent (MBS). MBS has the dual function of being a mutual solvent and a sludge and emulsion control additive. The paper discusses acidizing problems, acid additives, handling options, and a case history of the Main Pass A field.

  19. Soft X-ray Microscopy of Green Cements

    SciTech Connect

    Monteiro, P. J. M.; Mancio, M.; Chae, R.; Ha, J.; Kirchheim, A. P.; Fischer, P.; Tyliszczak, T.

    2011-09-09

    The present status of the cement and concrete industry is not sustainable. The production of Portland cement is responsible for 7% of the CO{sub 2} emissions in the world and existing reinforced concrete infrastructure is deteriorating at a fast pace. The change in the existing technology requires new developments in our understanding of the nanostructure of hydration products and the complex deterioration reactions. We have been developing an elaborate research program to advance the existing cement and concrete science by characterizing its nanostructure by synchrotron radiation. A new generation of green cements is being studied using high-resolution soft x-ray microscopy at the nano-level.

  20. High-productivity automatic GTAW process

    SciTech Connect

    Imaizumi, H.; Kato, T.; Murakami, Y.

    1994-12-31

    Gas tungsten arc welding (GTAW) has, since developed by AIRCO, spread globally as a weld process which assures a quality weld. However, the only drawback with GTAW is low productivity and we have challenged the subject in how we could improve that. To that end, we set the target of 3 times deposition rate as compared to conventional TIG. With conventional TIG arc, arc spread angle ranges 130{degrees} to 140{degrees}; to improve energy density, we have employed double flux TIG of SAF, France to converge the arc down to 80{degrees}. Consequently, energy density was upped to 4 times of conventional TIG, thus penetration depth and filler wire feed rated increased up to 2 to 4 times. We have succeeded in controlling cool-down in the molten pool, enabling the utilization of highly-converged TIG arc and preventing deposited metals burn-through for cleaner weld process, high-productivity GTAW. We find that: (1) The TIG arc spread angle is convergeable from 140{degrees} down to 80{degrees}; heat energy to be 3.5 times of that obtainable conventionally. (2) 65{emdash}80 g/min attained with 500A and C.S. in flat position, and 35{emdash}40 g/min., with all-position pipe weld. (3) 2{emdash}3 times efficiency improvement, obtained with work in C.S., S.S., and Inconel. (4) Excellent impact value obtainable despite heat-input increase. (5) Fume-less, spatterless, gouging-less and grindingless weld is obtainable; we were successful in improving the operational environment.

  1. Atmospheric Processing Module for Mars Propellant Production

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony; Gibson, Tracy; Captain, James; Athman, Robert; Nugent, Matthew; Parks, Steven; Devor, Robert

    2013-01-01

    The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methane/oxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (approx.8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO2 is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a HiCO2 recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO2/hr for 14 hr, (3) the testing of the CO2 freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH4/hr and 71.3 g H2O/hr along with verification of their purity. The resulting 2.22 kg of CH4/O2 propellant per 14 hr day (including O2 from electrolysis of water recovered from regolith, which also supplies the H2 for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASA's new Mars exploration plans will be discussed.

  2. Atmospheric Processing Module for Mars Propellant Production

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony; Gibson, Tracy; Captain, James; Athman, Robert; Nugent, Matthew; Parks, Steven; Devor, Robert

    2013-01-01

    The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methane/oxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO2 is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a HiCO2 recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO2/hr for 14 hr, (3) the testing of the CO2 freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH4/hr and 71.3 g H20/hr along with verification of their purity. The resulting 2.22 kg of CH4/O2 propellant per 14 hr day (including O2 from electrolysis of water recovered from regolith, which also supplies the H2 for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASA's new Mars exploration plans will be discussed.

  3. Anisotropic porous metals production by melt processing

    SciTech Connect

    Shapovalov, V.; Boiko, L.; Baldwin, M.D.; Maguire, M.C.; Zanner, F.J.

    1997-02-01

    The collapse of the Soviet Union has left many of its scientific institutes and technical universities without their traditional backbone of financial support. In an effort to stem the export of science to nations advocating nuclear proliferation, and to acquire potentially useful technology, several US government-sponsored programs have arise to mine the best of former USSR scientific advances. In the field of metallurgy, the earliest institutes to be investigated by Sandia National Laboratories are located in Ukraine. In particular, scientists at the State Metallurgical Academy have developed unique porous metals, resembling what could be described as gas-solid ``eutectic``. While porous metals are available in the US and other western countries, none have the remarkable structure and properties of these materials. Sandia began a collaborative program with the Ukrainian scientists to bring this technology to the US, verify the claims regarding these materials, and begin production of the so-called Gasars. This paper will describe the casting process technology and metallurgy associated with the production of Gasars, and will review the progress of the collaborative project.

  4. Crushed cement concrete substitution for construction aggregates; a materials flow analysis

    USGS Publications Warehouse

    Kelly, Thomas

    1998-01-01

    An analysis of the substitution of crushed cement concrete for natural construction aggregates is performed by using a materials flow diagram that tracks all material flows into and out of the cement concrete portion of the products made with cement concrete: highways, roads, and buildings. Crushed cement concrete is only one of the materials flowing into these products, and the amount of crushed cement concrete substituted influences the amount of other materials in the flow. Factors such as availability and transportation costs, as well as physical properties, that can affect stability and finishability, influence whether crushed cement concrete or construction aggregates should be used or predominate for a particular end use.

  5. Technology Transfer and the Product Development Process

    SciTech Connect

    Mock, John E.

    1989-03-21

    It is my pleasure this morning to address a topic that is much talked about in passing but rarely examined from a first person point of view. That topic is Technology Transfer. Over the next 30 minutes I'd like to approach Technology Transfer within the context of the Product Development Process looking at it from the perspectives of the federal government researcher and the industry manufacturer/user. Fist let us recognize that we are living in an ''Information Age'', where global economic and military competition is determined as much by technology as it is by natural resource assets. It is estimated that technical/scientific information is presently growing at a rate of l3 percent per year; this is expected to increase to 30 percent per year by the turn of the century. In fact, something like 90 percent of all scientific knowledge has been generated in the last 30 years; this pool will double again in the next 10-15 years (Exhibit 1). Of all the scientists and engineers throughout history, 90% live and work in the present time. Successfully managing this technical information/knowledge--i.e., transforming the results of R&D to practical applications--will be an important measure of national strength. A little over a dozen years ago, the United States with only 5 percent of the world's population was generating approximately 75 percent of the world's technology. The US. share is now 50 percent and may decline to 30 percent by the turn of the century. This decline won't be because of downturn in U.S. technological advances but because the other 95 percent of the world's population will be increasing its contribution. Economic and military strength then, will be determined by how quickly and successfully companies, industries, and nations can apply new technological information to practical applications--i.e., how they manage technology transfer within the context of the product development process. Much discussion and pronouncements are ongoing in public forums today over the apparent decline in global competitiveness of U.S. industry. The question is why does U.S. industry not succeed in the development and marketing of competitive products when they lead in the generation of new technology.

  6. Aluminum-rich belite sulfoaluminate cements: Clinkering and early age hydration

    SciTech Connect

    Martin-Sedeno, M. Carmen; Cuberos, Antonio J.M.; De la Torre, Angeles G.; Alvarez-Pinazo, Gema; Ordonez, Luis M.; Gateshki, Milen; Aranda, Miguel A.G.

    2010-03-15

    Belite sulfoaluminate (BSA) cements have been proposed as environmentally friendly building materials, as their production may release up to 35% less CO{sub 2} into the atmosphere when compared to ordinary Portland cements. Here, we discuss the laboratory production of three aluminum-rich BSA clinkers with nominal mineralogical compositions in the range C{sub 2}S (50-60%), C{sub 4}A{sub 3}$ (20-30%), CA (10%) and C{sub 12}A{sub 7} (10%). Using thermogravimetry, differential thermal analysis, high temperature microscopy, and X-ray powder diffraction with Rietveld quantitative phase analysis, we found that burning for 15 min at 1350 deg. C was the optimal procedure, in these experimental conditions, for obtaining the highest amount of C{sub 4}A{sub 3}$, i.e. a value as close as possible to the nominal composition. Under these experimental conditions, three different BSA clinkers, nominally with 20, 30 and 30 wt.% of C{sub 4}A{sub 3}$, had 19.6, 27.1 and 27.7 wt.%, C{sub 4}A{sub 3}$ respectively, as determined by Rietveld analysis. We also studied the complex hydration process of BSA cements prepared by mixing BSA clinkers and gypsum. We present a methodology to establish the phase assemblage evolution of BSA cement pastes with time, including amorphous phases and free water. The methodology is based on Rietveld quantitative phase analysis of synchrotron and laboratory X-ray powder diffraction data coupled with chemical constraints. A parallel calorimetric study is also reported. It is shown that the beta-C{sub 2}S phase is more reactive in aluminum-rich BSA cements than in standard belite cements. On the other hand, C{sub 4}A{sub 3}$ reacts faster than the belite phases. The gypsum ratio in the cement is also shown to be an important factor in the phase evolution.

  7. Process for production of a borohydride compound

    DOEpatents

    Allen, Nathan Tait; Butterick, III, Robert; Chin, Arthur Achhing; Millar, Dean Michael; Molzahn, David Craig

    2014-08-19

    A process for production of a borohydride compound M(BH.sub.4).sub.y. The process has three steps. The first step combines a compound of formula (R.sup.1O).sub.yM with aluminum, hydrogen and a metallic catalyst containing at least one metal selected from the group consisting of titanium, zirconium, hafnium, niobium, vanadium, tantalum and iron to produce a compound of formula M(AlH.sub.3OR.sup.1).sub.y, wherein R.sup.1 is phenyl or phenyl substituted by at least one alkyl or alkoxy group; M is an alkali metal, Be or Mg; and y is one or two; wherein the catalyst is present at a level of at least 200 ppm based on weight of aluminum. The second step combines the compound of formula M(AlH.sub.3OR.sup.1).sub.y with a borate, boroxine or borazine compound to produce M(BH.sub.4).sub.y and a byproduct mixture containing alkali metal and aluminum aryloxides. The third step separates M(BH.sub.4).sub.y from the byproduct mixture.

  8. Low fluid leakoff cementing compositions and filtration control additive for cement

    SciTech Connect

    Forrest, G.T.

    1993-07-20

    A cementing composition is described, for cementing oil or gas wells penetrating subterranean formations, capable of forming a fluid slurry when mixed with water comprising: dry hydraulic cement; and a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh. In a process for cementing a casing in an oil or gas well penetrating a subterranean formation wherein a cement slurry, formed by mixing water and hydraulic cement, is pumped down the well to flow upwardly between the casing and the subterranean formation, the improvement is described comprising: utilizing as a filtration control additive of from about 0.2 to 5.0 percent by weight, based upon dry hydraulic cement, of finely ground peanut hulls, and utilizing finely ground peanut hulls wherein 10 percent or more of the finely ground peanut hulls is in the particle size range of less than 20 standard sieve mesh and greater than 500 standard sieve mesh.

  9. Lunar cement and lunar concrete

    NASA Technical Reports Server (NTRS)

    Lin, T. D.

    1991-01-01

    Results of a study to investigate methods of producing cements from lunar materials are presented. A chemical process and a differential volatilization process to enrich lime content in selected lunar materials were identified. One new cement made from lime and anorthite developed compressive strengths of 39 Mpa (5500 psi) for 1 inch paste cubes. The second, a hypothetical composition based on differential volatilization of basalt, formed a mineral glass which was activated with an alkaline additive. The 1 inch paste cubes, cured at 100C and 100 percent humidity, developed compressive strengths in excess of 49 Mpa (7100 psi). Also discussed are tests made with Apollo 16 lunar soil and an ongoing investigation of a proposed dry mix/steam injection procedure for casting concrete on the Moon.

  10. Lunar cement and lunar concrete

    NASA Astrophysics Data System (ADS)

    Lin, T. D.

    Results of a study to investigate methods of producing cements from lunar materials are presented. A chemical process and a differential volatilization process to enrich lime content in selected lunar materials were identified. One new cement made from lime and anorthite developed compressive strengths of 39 Mpa (5500 psi) for 1 inch paste cubes. The second, a hypothetical composition based on differential volatilization of basalt, formed a mineral glass which was activated with an alkaline additive. The 1 inch paste cubes, cured at 100C and 100 percent humidity, developed compressive strengths in excess of 49 Mpa (7100 psi). Also discussed are tests made with Apollo 16 lunar soil and an ongoing investigation of a proposed dry mix/steam injection procedure for casting concrete on the Moon.

  11. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2004-01-30

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries.

  12. 75 FR 4423 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Portland Cement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... February 5, 1985 (50 FR 5015). The last notification was filed with the Department on May 18, 2009. A notice was published in the Federal Register pursuant to Section 6(b) of the Act on August 9, 2009 (74 FR..., Wickliffe, OH; Air Products and Chemicals, Inc., Allentown, PA; LWB Refractories, York, PA;...

  13. 76 FR 34252 - Notice Pursuant to the National Cooperative Research and Production Act of 1993; Portland Cement...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-13

    ... published a notice in the Federal Register pursuant to Section 6(b) of the Act on February 5, 1985 (50 FR... in the Federal Register pursuant to Section 6(b) of the Act on March 7, 2011 (76 FR 12370). Patricia... Antitrust Division Notice Pursuant to the National Cooperative Research and Production Act of 1993;...

  14. Accelerated Biodegradation of Cement by Sulfur-Oxidizing Bacteria as a Bioassay for Evaluating Immobilization of Low-Level Radioactive Waste

    PubMed Central

    Aviam, Orli; Bar-Nes, Gabi; Zeiri, Yehuda; Sivan, Alex

    2004-01-01

    Disposal of low-level radioactive waste by immobilization in cement is being evaluated worldwide. The stability of cement in the environment may be impaired by sulfur-oxidizing bacteria that corrode the cement by producing sulfuric acid. Since this process is so slow that it is not possible to perform studies of the degradation kinetics and to test cement mixtures with increased durability, procedures that accelerate the biodegradation are required. Semicontinuous cultures of Halothiobacillus neapolitanus and Thiomonas intermedia containing thiosulfate as the sole energy source were employed to accelerate the biodegradation of cement samples. This resulted in a weight loss of up to 16% after 39 days, compared with a weight loss of 0.8% in noninoculated controls. Scanning electron microscopy of the degraded cement samples revealed deep cracks, which could be associated with the formation of low-density corrosion products in the interior of the cement. Accelerated biodegradation was also evident from the leaching rates of Ca2+ and Si2+, the major constituents of the cement matrix, and Ca exhibited the highest rate (up to 20 times greater than the control rate) due to the reaction between free lime and the biogenic sulfuric acid. Leaching of Sr2+ and Cs+, which were added to the cement to simulate immobilization of the corresponding radioisotopes, was also monitored. In contrast to the linear leaching kinetics of calcium, silicon, and strontium, the leaching pattern of cesium produced a saturation curve similar to the control curve. Presumably, the leaching of cesium is governed by the diffusion process, whereas the leaching kinetics of the other three ions seems to governed by dissolution of the cement. PMID:15466547

  15. 9 CFR 590.680 - Approval of labeling for egg products processed in exempted egg products processing plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Approval of labeling for egg products processed in exempted egg products processing plants. 590.680 Section 590.680 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION...

  16. 9 CFR 590.680 - Approval of labeling for egg products processed in exempted egg products processing plants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Approval of labeling for egg products processed in exempted egg products processing plants. 590.680 Section 590.680 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION...

  17. 9 CFR 590.680 - Approval of labeling for egg products processed in exempted egg products processing plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Approval of labeling for egg products processed in exempted egg products processing plants. 590.680 Section 590.680 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION...

  18. 9 CFR 590.680 - Approval of labeling for egg products processed in exempted egg products processing plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Approval of labeling for egg products processed in exempted egg products processing plants. 590.680 Section 590.680 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION...

  19. 9 CFR 590.680 - Approval of labeling for egg products processed in exempted egg products processing plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Approval of labeling for egg products processed in exempted egg products processing plants. 590.680 Section 590.680 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EGG PRODUCTS INSPECTION INSPECTION...

  20. Matrix control cementing slurry

    SciTech Connect

    Arpenter, R.B.

    1986-02-11

    This patent describes a method of cementing a well bore. The method consists of 1.) mixing together at ambient temperatures at the well surface a hydraulic cement, water, in an effective amount to produce a pumpable slurry, and a polyvinyl acetate-polyvinyl alcohol polymer, which is insoluble in the slurry at ambient temperatures. The polymer has a greater than about 95 percent acetate groups converted to hydroxyl groups. The polymer is heated to actuable solubilization in the cement slurry at temperatures above about 120/sup 0/F. The solubilizing of the polyvinyl acetate-polyvinyl alcohol polymer in the slurry prior to the setting of the slurry by pumping the cement slurry to a desired location in the well bore. This action increases the temperature of the slurry; and 2.) allows the cement slurry to harden to a solid mass.

  1. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2002-01-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report includes results from laboratory testing of ULHS systems along with other lightweight cement systems: foamed and sodium silicate slurries. Comparison studies of the three cement systems examined several properties: tensile strength, Young's modulus, water permeability, and shear bond. Testing was also done to determine the effect that temperature cycling has on the shear bond properties of the cement systems. In addition, analysis was carried out to examine alkali silica reactivity of slurries containing ULHS. Data is also presented from a study investigating the effects of mixing and pump circulation on breakage of ULHS. Information is also presented about the field application of ULHS in cementing a 7-in. intermediate casing in south Texas.

  2. Hydration kinetics of cement composites with varying water-cement ratio using terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Ray, Shaumik; Dash, Jyotirmayee; Devi, Nirmala; Sasmal, Saptarshi; Pesala, Bala

    2015-03-01

    Cement is mixed with water in an optimum ratio to form concrete with desirable mechanical strength and durability. The ability to track the consumption of major cement constituents, viz., Tri- and Dicalcium Silicates (C3S, C2S) reacting with water along with the formation of key hydration products, viz., Calcium-Silicate-Hydrate (C-S-H) which gives the overall strength to the concrete and Calcium Hydroxide (Ca(OH)2), a hydration product which reduces the strength and durability, using an efficient technique is highly desirable. Optimizing the amount of water to be mixed with cement is one of the main parameters which determine the strength of concrete. In this work, THz spectroscopy has been employed to track the variation in hydration kinetics for concrete samples with different water-cement ratios, viz., 0.3, 0.4, 0.5 and 0.6. Results show that for the sample with water-cement ratio of 0.3, significant amount of the C3S and C2S remain unreacted even after the initial hydration period of 28 days while for the cement with water-cement ratio of 0.6, most of the constituents get consumed during this stage. Analysis of the formation of Ca(OH)2 has been done which shows that the concrete sample with water-cement ratio of 0.6 produces the highest amount of Ca(OH)2 due to higher consumption of C3S/C2S in presence of excess water which is not desirable. Samples with water-cement ratio of 0.4 and 0.5 show more controlled reaction during the hydration which can imply formation of an optimized level of desired hydration products resulting in a more mechanically strong and durable concrete.

  3. Atmospheric Processing Module for Mars Propellant Production

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony C.

    2014-01-01

    The multi-NASA center Mars Atmosphere and Regolith COllectorPrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methaneoxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO(sub 2) is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a H(sub 2)CO(sub 2) recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO(sub 2) hr for 14 hr, (3) the testing of the CO(sub 2) freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH(sub 4) hr and 71.3 g H(sub 2)O hr along with verification of their purity. The resulting 2.22 kg of CH(sub 2)O(sub 2) propellant per 14 hr day (including O(sub 2) from electrolysis of water recovered from regolith, which also supplies the H(sub 2) for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASAs new Mars exploration plans will be discussed.

  4. Atmospheric Processing Module for Mars Propellant Production

    NASA Technical Reports Server (NTRS)

    Muscatello, A.; Devor, R.; Captain, J.

    2014-01-01

    The multi-NASA center Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project was established to build and demonstrate a methaneoxygen propellant production system in a Mars analog environment. Work at the Kennedy Space Center (KSC) Applied Chemistry Laboratory is focused on the Atmospheric Processing Module (APM). The purpose of the APM is to freeze carbon dioxide from a simulated Martian atmosphere containing the minor components nitrogen, argon, carbon monoxide, and water vapor at Martian pressures (approx. 8 torr) by using dual cryocoolers with alternating cycles of freezing and sublimation. The resulting pressurized CO(sub 2) is fed to a methanation subsystem where it is catalytically combined with hydrogen in a Sabatier reactor supplied by the Johnson Space Center (JSC) to make methane and water vapor. We first used a simplified once-through setup and later employed a H(sub 2)CO(sub 2) recycling system to improve process efficiency. This presentation and paper will cover (1) the design and selection of major hardware items, such as the cryocoolers, pumps, tanks, chillers, and membrane separators, (2) the determination of the optimal cold head design and flow rates needed to meet the collection requirement of 88 g CO(sub 2) hr for 14 hr, (3) the testing of the CO(sub 2) freezer subsystem, and (4) the integration and testing of the two subsystems to verify the desired production rate of 31.7 g CH(sub 4) hr and 71.3 g H(sub 2)O hr along with verification of their purity. The resulting 2.22 kg of CH(sub 2)O(sub 2) propellant per 14 hr day (including O(sub 2) from electrolysis of water recovered from regolith, which also supplies the H(sub 2) for methanation) is of the scale needed for a Mars Sample Return mission. In addition, the significance of the project to NASAs new Mars exploration plans will be discussed.

  5. Fractional exhaled nitric oxide among cement factory workers: a cross sectional study

    PubMed Central

    Tungu, Alexander Mtemi; Brtveit, Magne; Mamuya, Simon D; Moen, Bente E

    2013-01-01

    Background It has been suggested that dust exposure causes airway inflammation among cement factory workers. However, there is limited information on the mechanisms of this effect. We explored any associations between total dust exposure and fractional exhaled nitric oxide (FENO) as a marker of airway eosinophilic inflammation among cement production workers in Tanzania. We also examined possible differences in FENO concentration between workers in different parts of the production line. Methodology We examined 127 cement workers and 28 controls from a mineral water factory. An electrochemistry-based NIOX MINO device was used to examine FENO concentration. Personal total dust was collected from the breathing zone of the study participants using 37?mm cellulose acetate filters placed in three-piece plastic cassettes. Interviews on workers background information were conducted in the Swahili language. Results We found equal concentrations of FENO among exposed workers and controls (geometric mean (GM)=16?ppb). The GM for total dust among the exposed workers and controls was 5.0 and 0.6?mg/m3, respectively. The FENO concentrations did not differ between the exposed workers with high (GM?5?mg/m3) and low (GM<5?mg/m3) total dust exposure. There was no significant difference in FENO concentration between workers in the two main stages of the cement production process. Conclusions We did not find any difference in FENO concentration between dust-exposed cement workers and controls, and there were similar FENO concentrations among workers in the two main stages of cement production. PMID:23243102

  6. Writing in dyslexia: product and process.

    PubMed

    Morken, Frøydis; Helland, Turid

    2013-08-01

    Research on dyslexia has largely centred on reading. The aim of this study was to assess the writing of 13 children with and 28 without dyslexia at age 11 years. A programme for keystroke logging was used to allow recording of typing activity as the children performed a sentence dictation task. Five sentences were read aloud twice each. The task was to type the sentence as correctly as possible, with no time constraints. The data were analysed from a product (spelling, grammar and semantics) and process (transcription fluency and revisions) perspective, using repeated measures ANOVA and t-tests to investigate group differences. Furthermore, the data were correlated with measures of rapid automatic naming and working memory. Results showed that the group with dyslexia revised their texts as much as the typical group, but they used more time, and the result was poorer. Moreover, rapid automatic naming correlated with transcription fluency, and working memory correlated with the number of semantic errors. This shows that dyslexia is generally not an issue of effort and that cognitive skills that are known to be important for reading also affect writing. PMID:23720272

  7. Fermentation process for production of Xanthan

    SciTech Connect

    Wernau, W.C.

    1981-08-04

    Xanthomonas polymers used in displacement of oil from partially depleted reservoirs are produced in higher concentrations and yields by the gradual addition of a source of assimilable carbon, preferably glucose, to the aqueous nutrient medium during the course of a Xanthomonas fermentation. The cost factors involved in secondary and tertiary oil recovery and the competitive use of diluted Xanthomonas whole broths in such recovery dictate increasing the fermentation concentration of the Xanthomonas polymers. Reduced shipping costs, broth storage facilities, and handling costs are some of the benefits derived. Furthermore, reduced volumes of solvent are needed for recovery when initial broth concentrations are high in those processes where Xanthomonas gums are recovered for oil recovery applications. Increasing the fermentation yield of a desired microbial product is accomplished by adding or feeding a nutrient or nutrients during the course of the fermentation cycle. The addition of glucose solution is started immediately after inoculation. The glucose is fed at an exponentially increasing rate up to 24 hr after inoculation and thereafter at a constant rate. Other nutrients may be fed with the source of assimilable carbon. (Also related to US 11/30/78 Appl. 964,951). 4 claims.

  8. Fermentation process for production of xanthan

    SciTech Connect

    Wernau, W.C.

    1981-08-04

    Xanthomonas polymers used in displacement of oil from partially depleted reservoirs are produced in higher concentrations and yields by the gradual addition of a source of assimilable carbon, preferably glucose, to the aqueous nutrient medium during the course of a Xanthomonas fermentation. The cost factors involved in secondary and tertiary oil recovery and the competitive use of diluted Xanthomonas whole broths in such recovery dictate increasing the fermentation concentration of the Xanthomonas polymers. Reduced shipping costs, broth storage facilities, and handling costs are some of the benefits derived. Furthermore, reduced volumes of solvent are needed for recovery when initial broth concentrations are high in those processes where Xanthomonas gums are recovered for oil recovery applications. Increasing the fermentation yield of a desired microbial product is accomplished by adding or feeding a nutrient or nutrients during the course of the fermentation cycle. The addition of glucose solution is started immediately after inoculation. The glucose is fed at an exponentially increasing rate up to 24 hr after inoculation and thereafter at a constant rate. Other nutrients may be fed with the source of assimilable carbon. (Also related to US 11/30/78 Appl. 964,951). 4 claims.

  9. Processing of Spent Ion Exchange Resins in a Rotary Calciner - 12212

    SciTech Connect

    Kascheev, Vladimir; Musatov, Nikolay

    2012-07-01

    Processing Russian nuclear ion exchange resin KU-2 using a 'Rotary' calciner was conducted. The resulting product is a dry free flowing powder (moisture content 3 wt.%, Angle of repose of ? 20 deg.). Compared with the original exchange resin the volume of the final product is about 3 times less.. Rotary calciner product can be stored in metal drums or in special reinforced concrete cubicles. After thermal treatment in a rotary calciner, the spent resin product can be solidified in cement yielding the following attributes: - The cemented waste is only a 35% increase over the volume of powder product; - The volume of cement calciner product is almost 9 times less (8.7) than the volume of cement solidified resin; - The mechanical strength of cemented calciner product meets the radioactive waste regulations in Russia. (authors)

  10. Reaction of CO2 and brine at the interface between Portland cement and casing steel: Application to CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Carey, J. W.; Zhang, J.; Lichtner, P. C.; Grigg, R.; Svec, B.; Pawar, R.

    2008-12-01

    Prediction of CO2 leakage through wellbore systems is a multiscale problem in geologic sequestration. In order for wellbore leakage to occur, km-scale processes must deliver CO2 from the point of injection to the wellbore. But, in order for the wellbore to actually leak, μm-scale processes must operate to allow CO2 to flow up the wellbore. In this study, we describe experiments and modeling of microscale processes accompanying CO2 leakage along the cement-casing interface. This work fits within a broader predictive study of CO2 sequestration performance (Viswanathan et al. 2008, Env Sci and Tech, in press) that includes calculation of CO2-migration times to wellbores. Experiments carried out in this report consisted of synthetic wellbore systems constructed of Portland cement and casing-grade steel in which a mixture of CO2 and brine were forced along the cement-casing interface at in situ sequestration conditions (40 °C and 14 MPa). The CO2-brine mixture was pre- equilibrated by flow through limestone before encountering the cement-casing composite. (The limestone- equilibrated fluid was calculated to be strongly out of equilibrium with both cement and the casing.) We used a high CO2-brine flux (10-20 ml/hour along the interface) and hypothesized that the interface would widen with time due to dissolution of either or both cement and steel. In addition to experiments, we conducted reactive transport modeling of cement reactivity using FLOTRAN, which was modified to allow representation of solid solution in the dominant cement phase, calcium-silicate-hydrate. We also developed a corrosion model for the steel. The experimental results showed that the steel was more reactive than the Portland cement. Extensive deposits or oxidation products of FeCO3-rich material developed at the interface and in some places led to an apparent closure of the interface despite the large flux through the system. In contrast, alteration of the cement appeared to be limited by diffusion of CO2 into the cement matrix and carbonation of the cement to CaCO3. The cement interface did not appear to have been significantly eroded. The experiment was used to calibrate numerical models for corrosion rates and for cement carbonation. These results were applied to interpret samples recovered from a CO2-enhanced oil recovery field (SACROC in West Texas; Carey et al. 2007, Int J. Greenhouse Gas Control, 1: 75-85). The results suggest that CO2-brine flux must have been limited along the cement-casing interface because the casing showed very little corrosion. They also suggest that CO2 penetration along the cement-formation interface was limited in volume because the depth of carbonation at SACROC was limited. These microscale models suggest that cement-casing flow has the potential to be self-limiting due to precipitation of CO2 and that standard logging measurements of casing integrity can be used to assess whether significant flow of CO2-brine has occurred at the casing interface.

  11. Integrated Product and Process Data for B2B Collaboration

    SciTech Connect

    Kulvatunyou, Boonserm; Ivezic, Nenad; Jones, Albert; Wysk, Richard A.

    2003-09-01

    Collaborative development of engineered products in a business-to-business (B2B) environment will require more than just the selection of components from an on-line catalogue. It will involve the electronic exchange of product, process, and production engineering information during both design and manufacturing. While the state-of-the-practice does include a variety of ways to exchange product data electronically, it does not extend to the exchange of manufacturing process data. The reason is simple; process data is usually tied to specific manufacturing resources. These resources are not known typically at product development time. This paper proposes an approach, called an Integrated Product and Process Data (IPPD), where manufacturing process data is considered during product development. This approach replaces traditional process plans, which are resource specific, with a resource-independent process representation. Such a representation will allow a much wider collaboration among business partners and provide the necessary base for collaborative product development.

  12. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-07-31

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the eleventh quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. This report provides a progress summary of ASR testing. The original laboratory procedure for measuring set cement expansion resulted in unacceptable erosion of the test specimens. In subsequent tests, a different expansion procedure was implemented and an alternate curing method for cements formulated with TXI Lightweight cement was employed to prevent sample failure caused by thermal shock. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but data for some compositions were still questionable. Additional modification of test procedures for compositions containing TXI Lightweight cement were implemented and testing is ongoing.

  13. Timing of syntaxial cement

    SciTech Connect

    Perkins, R.D.

    1985-02-01

    Echinodermal fragments are commonly overgrown in ancient limestones, with large single crystals growing in optical continuity over their skeletal hosts (i.e., syntaxial overgrowths). Such syntaxial cements are usually considered to have precipitated from meteoric pore waters associated with a later stage of subaerial exposure. Although several examples have been reported from ancient carbonates where petrographic relationships may indicate an early submarine formation of syntaxial cement, no occurrences have been noted in Holocene submarine-cemented rocks. Syntaxial cements of submarine origin have been found in Bermuda beachrock where isopachous high-magnesian calcite cements merge with large optically continuous crystals growing on echinodermal debris. Examination of other Holocene sediments cemented by magnesian calcite indicates that echinodermal fragments are not always overgrown syntaxially, but may be rimmed by microcrystalline calcite. The reason for this difference is not clear, although it may be a function of the spacing of nucleation sites and rates of crystal growth. A review of syntaxial cements from several localities in ancient carbonate sequences reveals that many are best interpreted as having formed in the submarine setting, whereas it is more clear that others formed from meteoric precipitation. These occurrences suggest that care should be exercised in inferring meteoric diagenesis from syntaxial overgrowths and that the possibility of submarine formation should be considered.

  14. The density of cement phases

    SciTech Connect

    Balonis, M. Glasser, F.P.

    2009-09-15

    The densities of principal crystalline phases occurring in Portland cement are critically assessed and tabulated, in some cases with addition of new data. A reliable and self-consistent density set for crystalline phases was obtained by calculating densities from crystallographic data and unit cell contents. Independent laboratory work was undertaken to synthesize major AFm and AFt cement phases, determine their unit cell parameters and compare the results with those recorded in the literature. Parameters were refined from powder diffraction patterns using CELREF 2 software. A density value is presented for each phase, showing literature sources, in some cases describing limitations on the data, and the weighting attached to numerical values where an averaging process was used for accepted data. A brief discussion is made of the consequences of the packing of water to density changes in AFm and AFt structures.

  15. Bioreactor and process design for biohydrogen production.

    PubMed

    Show, Kuan-Yeow; Lee, Duu-Jong; Chang, Jo-Shu

    2011-09-01

    Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. It has the potential for renewable biofuel to replace current hydrogen production which rely heavily on fossil fuels. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of advances in bioreactor and bioprocess design for biohydrogen production. The state-of-the art of biohydrogen production is discussed emphasizing on production pathways, factors affecting biohydrogen production, as well as bioreactor configuration and operation. Challenges and prospects of biohydrogen production are also outlined. PMID:21624834

  16. Paleoenvironmental Controls on Early Cementation of Organic-Rich Shales in the Eagle Ford Group

    NASA Astrophysics Data System (ADS)

    Kruse, K.; Tice, M. M.

    2013-12-01

    Early carbonate cements have the potential to alter fracture toughness, and carbonate can be either promoted or inhibited by microbial processes in different redox zones. It is therefore possible that basin redox evolution could indirectly control early diagenesis and modify reservoir properties of corresponding shale units. The goals of this study are to analyze geochemical characteristics of the Late Cretaceous Eagle Ford Group in McMullen County, Texas in order to test the hypotheses that (1) the redox state of the water column controlled carbonate cement abundance and (2) carbonate cement lowered organic matter content by volumetric dilution. An X-ray analytical microscope was used to map elemental compositions of fresh core samples spanning the Eagle Ford Group. Resultant maps were used to characterize carbonate cements and to estimate the redox state of the overlying water column during deposition as proxied by the relative abundances of the trace metals Mo, V, Cr, and Zn. Preliminary results indicate that cementation occurred early relative to compaction. Ti-K?1-normalized Mo K?1 and Ca K?1 fluorescence intensities are positively correlated throughout the unit, suggesting that carbonate cementation was promoted by basin euxinia. Total organic carbon is negatively correlated with (Ca K?1)/(Ti K?1) fluorescence ratio in the upper Eagle Ford Group, consistent with volumetric dilution of sedimentary organic matter by diagenetic cementation prior to compaction. In contrast, there is no significant correlation between total organic carbon and carbonate content in the more organic-rich lower Eagle Ford Group, suggesting that variations in organic matter production, preservation, or dilution by siliciclastic input were also important in controlling final organic content.

  17. From Sentence Production to Text Production: Investigating Fundamental Processes.

    ERIC Educational Resources Information Center

    Fayol, Michel

    1991-01-01

    Presents a review of cognitive psychology research dealing with the organization and functioning of oral and written language production mechanisms. Discusses works dealing with the microstructural aspects of language, primarily oral production. Describes how the research perspective has evolved from modular to connectionist models. Examines the

  18. PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS

    SciTech Connect

    Dady Dadyburjor; Chong Chen; Elliot B. Kennel; Liviu Magean; Peter G. Stansberry; Alfred H. Stiller; John W. Zondlo

    2006-02-23

    The purpose of this DOE-funded effort is to develop technologies for carbon products from coal-derived feedstocks. Carbon products can include precursor materials such as solvent extracted carbon ore (SECO) and synthetic pitch (Synpitch). In addition, derived products include carbon composites, fibers, foams and others. Key milestones included producing hydrogenated coal in the Hydrotreating Facility for the first time. The facility is now operational, although digital controls have not yet been completely wired. In addition, ultrasound is being used to investigate enhanced dissolution of coal. Experiments have been carried out.

  19. Developmental study of a low-pH magnesium phosphate cement for environmental applications.

    PubMed

    Iyengar, S R; Al-Tabbaa, Abir

    2007-12-01

    This paper presents a laboratory investigation into the development of a low-pH magnesium phosphate-based cement for use in in-situ stabilisation/solidification systems, as a more effective alternative to Portland cement. The idea is to develop a cement-based binder with a low enough pH to facilitate biodegradation in combination with stabilisation/solidification processes. Potassium dihydrogen orthophosphate was selected as the phosphate source, dead-burned magnesia as the magnesium source and boric acid as the retarder. The range of mixes were tested primarily on their pH development which was found to be in the range of 6-9.5 for a magnesia to phosphate ratio range of 1:1 to 1:5. The testing revealed a dense microstructure, high early-age strength development and low volume expansion of the developed cement. Observed fracturing of some of the cured cement samples has been related to the curing conditions and the impurities present in the magnesia. On the basis of microstructural examination, observed white crystalline deposits on cured samples are likely to be a reaction product of magnesia and potassium dihydrogen phosphate. PMID:18341149

  20. PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

    DOEpatents

    Spedding, F.H.; Butler, T.A.; Johns, I.B.

    1959-03-10

    The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

  1. Architectures, Representations and Processes of Language Production

    ERIC Educational Resources Information Center

    Alario, F.-Xavier; Costa, Albert; Ferreira, Victor S.; Pickering, Martin J.

    2006-01-01

    The authors present an overview of recent research conducted in the field of language production based on papers presented at the first edition of the International Workshop on Language Production (Marseille, France, September 2004). This article comprises two main parts. In the first part, consisting of three sections, the authors review the

  2. Hydrogen in the Methanol Production Process

    ERIC Educational Resources Information Center

    Kralj, Anita Kovac; Glavic, Peter

    2006-01-01

    Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for…

  3. Powder-Metallurgy Process And Product

    NASA Technical Reports Server (NTRS)

    Paris, Henry G.

    1988-01-01

    Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

  4. Hydrogen in the Methanol Production Process

    ERIC Educational Resources Information Center

    Kralj, Anita Kovac; Glavic, Peter

    2006-01-01

    Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for

  5. Productive Skills for Process Operatives. Skills Review.

    ERIC Educational Resources Information Center

    Giles, L.; Kodz, J.; Evans, C.

    A study of process operatives examined the developments in processing work in 20 organizations within the chemical and food and drink processing industries. Seven exploratory interviews were followed by 20 employer interviews. Technological innovations caused job losses and layoffs. Organizational responses adopted to meet increasing competitive…

  6. Liquid cement premix for improved abandonment and workover operations

    SciTech Connect

    Rae, P.; Johnston, N.

    1996-12-31

    Many cementing operations, such as well abandonment, work-over, etc., incur logistical, personnel and operational problems, and costs, disproportionate to the size of the cementing operation. A typical example being offshore well abandonment on a platform which has limited accommodation, no conventional cementing equipment, and where access, space or weight restrictions preclude its installation. This paper outlines the problems of abandonment and remote locations; it describes the concept, laboratory development, pilot testing, introduction and field use of a liquid cement premix. This novel approach helps reduce waste and minimize the environmental impact of the cementing operation and may be particularly suitable where small volumes of accurately mixed slurry are required, for example in coil tubing applications. It is, however, equally applicable for large volumes since the process lends itself to automation. The technique offers radical changes to cementing operations and equipment requirements, and direct savings to the operator through reduction in the costs of personnel, equipment mobilization, transport, installation, and material wastage.

  7. A literature review of mixed waste components: Sensitivities and effects upon solidification/stabilization in cement-based matrices

    SciTech Connect

    Mattus, C.H.; Gilliam, T.M.

    1994-03-01

    The US DOE Oak Ridge Field Office has signed a Federal Facility Compliance Agreement (FFCA) regarding Oak Ridge Reservation (ORR) mixed wastes subject to the land disposal restriction (LDR) provisions of the Resource conservation and Recovery Act. The LDR FFCA establishes an aggressive schedule for conducting treatability studies and developing treatment methods for those ORR mixed (radioactive and hazardous) wastes listed in Appendix B to the Agreement. A development, demonstration, testing, and evaluation program has been initiated to provide those efforts necessary to identify treatment methods for all of the wastes that meet Appendix B criteria. The program has assembled project teams to address treatment development needs in a variety of areas, including that of final waste forms (i.e., stabilization/solidification processes). A literature research has been performed, with the objective of determining waste characterization needs to support cement-based waste-form development. The goal was to determine which waste species are problematic in terms of consistent production of an acceptable cement-based waste form and at what concentrations these species become intolerable. The report discusses the following: hydration mechanisms of Portland cement; mechanisms of retardation and acceleration of cement set-factors affecting the durability of waste forms; regulatory limits as they apply to mixed wastes; review of inorganic species that interfere with the development of cement-based waste forms; review of radioactive species that can be immobilized in cement-based waste forms; and review of organic species that may interfere with various waste-form properties.

  8. Process simulation and economical evaluation of enzymatic biodiesel production plant.

    PubMed

    Sotoft, Lene Fjerbaek; Rong, Ben-Guang; Christensen, Knud V; Norddahl, Birgir

    2010-07-01

    Process simulation and economical evaluation of an enzymatic biodiesel production plant has been carried out. Enzymatic biodiesel production from high quality rapeseed oil and methanol has been investigated for solvent free and cosolvent production processes. Several scenarios have been investigated with different production scales (8 and 200 mio. kg biodiesel/year) and enzyme price. The cosolvent production process is found to be most expensive and is not a viable choice, while the solvent free process is viable for the larger scale production of 200 mio. kg biodiesel/year with the current enzyme price. With the suggested enzyme price of the future, both the small and large scale solvent free production proved viable. The product price was estimated to be 0.73-1.49 euro/kg biodiesel with the current enzyme price and 0.05-0.75 euro/kg with the enzyme price of the future for solvent free process. PMID:20171880

  9. 40 CFR 158.330 - Description of production process.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Description of production process. 158.330 Section 158.330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.330 Description of production process....

  10. 40 CFR 158.330 - Description of production process.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Description of production process. 158.330 Section 158.330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.330 Description of production process....

  11. 40 CFR 158.330 - Description of production process.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Description of production process. 158.330 Section 158.330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.330 Description of production process....

  12. A Prevalidation of the Product-Process Matrix

    ERIC Educational Resources Information Center

    Ashenbaum, Bryan

    2013-01-01

    A major challenge for instructors of supply chain and operations management (SCOM) courses is to help students who have never seen a production floor visualize concepts, such as the product-process matrix from standard introductory SCOM texts. This article presents a classroom exercise, which "prevalidates" the product-process matrix.

  13. A Prevalidation of the Product-Process Matrix

    ERIC Educational Resources Information Center

    Ashenbaum, Bryan

    2013-01-01

    A major challenge for instructors of supply chain and operations management (SCOM) courses is to help students who have never seen a production floor visualize concepts, such as the product-process matrix from standard introductory SCOM texts. This article presents a classroom exercise, which "prevalidates" the product-process matrix.…

  14. 40 CFR 158.330 - Description of production process.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Description of production process. 158.330 Section 158.330 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.330 Description of production process....

  15. Coupled X-ray Microtomography Imaging and Computational Fluid Dynamics Modeling for Evaluation of Wellbore Cement Fracture Evolution

    NASA Astrophysics Data System (ADS)

    Jung, H.; Kabilan, S.; Carson, J.; Kuprat, A.; Um, W.; Carroll, K. C.; Bonneville, A.; Fernandez, C.

    2013-12-01

    Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 degrees Celsius and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the opening of fractures due to crystallization-induced pressure, as well as disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. The study also suggests that in deep geological reservoirs the geochemical and geomechanical processes have coupled effects on the fracture evolution and fluid flow. Finally, it is important to emphasize that XMT imaging coupled with CFD modeling represents a powerful tool to visualize and quantify fracture evolution and permeability in geologic materials and predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal system.

  16. Reference Production: Production-Internal and Addressee-Oriented Processes

    ERIC Educational Resources Information Center

    Arnold, Jennifer

    2008-01-01

    This paper reviews research on the production of referential expressions, examining the choice between explicit and attenuated lexical forms (e.g., pronouns vs. names), and between acoustically prominent and attenuated pronunciations. Both choices can be explained in terms of addressee-design, in that explicit expressions tend to be used in

  17. Technical Writing: Process and Product. Third Edition.

    ERIC Educational Resources Information Center

    Gerson, Sharon J.; Gerson, Steven M.

    This book guides students through the entire writing process--prewriting, writing, and rewriting--developing an easy-to-use, step-by-step technique for writing the types of documents they will encounter on the job. It engages students in the writing process and encourages hands-on application as well as discussions about ethics, audience

  18. Method for cementing a well

    SciTech Connect

    Allen, T.E.

    1992-04-14

    This patent describes a method of performing a cement job on a well so that a cement slurry is made and placed in the well, it comprises: flowing cement and water through a mixer into a tub to provide a first body of cement slurry; flowing a portion of the first body of cement slurry into a displacement tank to provide a second body of cement slurry; flowing the second body of cement slurry from the displacement tank into the well; flowing displacement fluid into the displacement tank; and flowing displacement fluid from the displacement tank into the well behind the cement slurry to place the cement slurry at a desired location in the well.

  19. 9 CFR 381.306 - Processing and production records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Processing and production records. 381.306 Section 381.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION...

  20. 9 CFR 318.306 - Processing and production records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Processing and production records. 318.306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION ENTRY...

  1. 48 CFR 870.111-5 - Frozen processed food products.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Frozen processed food... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.111-5 Frozen processed food products. (a) The following frozen processed food products must have a label complying with the...

  2. 48 CFR 870.111-5 - Frozen processed food products.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Frozen processed food... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.111-5 Frozen processed food products. (a) The following frozen processed food products must have a label complying with the...

  3. 48 CFR 870.111-5 - Frozen processed food products.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Frozen processed food... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.111-5 Frozen processed food products. (a) The following frozen processed food products must have a label complying with the...

  4. 48 CFR 870.111-5 - Frozen processed food products.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Frozen processed food... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.111-5 Frozen processed food products. (a) The following frozen processed food products must have a label complying with the...

  5. 48 CFR 870.111-5 - Frozen processed food products.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Frozen processed food... DEPARTMENT SUPPLEMENTARY REGULATIONS SPECIAL PROCUREMENT CONTROLS Controls 870.111-5 Frozen processed food products. (a) The following frozen processed food products must have a label complying with the...

  6. 7 CFR 926.11 - Processed cranberries or cranberry products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Processed cranberries or cranberry products. 926.11... COLLECTION, REPORTING AND RECORDKEEPING REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER 926.11 Processed cranberries or cranberry products. Processed cranberries or...

  7. 7 CFR 926.11 - Processed cranberries or cranberry products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Processed cranberries or cranberry products. 926.11... COLLECTION, REPORTING AND RECORDKEEPING REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER 926.11 Processed cranberries or cranberry products. Processed cranberries or...

  8. 7 CFR 926.11 - Processed cranberries or cranberry products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Processed cranberries or cranberry products. 926.11... COLLECTION, REPORTING AND RECORDKEEPING REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER 926.11 Processed cranberries or cranberry products. Processed cranberries or...

  9. 7 CFR 926.11 - Processed cranberries or cranberry products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Processed cranberries or cranberry products. 926.11... COLLECTION, REPORTING AND RECORDKEEPING REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER 926.11 Processed cranberries or cranberry products. Processed cranberries or...

  10. 7 CFR 926.11 - Processed cranberries or cranberry products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Processed cranberries or cranberry products. 926.11... COLLECTION, REPORTING AND RECORDKEEPING REQUIREMENTS APPLICABLE TO CRANBERRIES NOT SUBJECT TO THE CRANBERRY MARKETING ORDER 926.11 Processed cranberries or cranberry products. Processed cranberries or...

  11. Development of an advanced continuous mild gasification process for the production of co-products. Quarterly report, January--March, 1996

    SciTech Connect

    O`Neal, G.W.

    1996-04-01

    Determination of the best furnace for a commercial coke plant is underway. A shuttle or tunnel kiln has economic advantage over a rotary hearth design. Production of 20 tons of coke in a small shuttle kiln is near completion which will provide experience for this design. Twenty tons of CTC continuous coke are being produced for testing at a General Motors` foundry. The production is approximately 75 percent complete. During this production, variables of the process are being studied to aid in design of a commercial coke plant. Raw material composition, blending, briquetting variables, and calcining heat profile are the major areas of interest. Western SynCoal Company produces a dried coal product from sub-bituminous coal. This upgraded product was evaluated for producing coke products by blending char from this coal product with the coal product along with suitable binders. The green briquettes were then calcined to produce coke. The resulting coke was judged to be usable as part of a cupola coke charge or as a fuel in cement kilns and sugar beet furnaces.

  12. The effect of white or grey PVC pipe and its joint solvents (primer and cement) on odour problems in drinking water distribution systems.

    PubMed

    Wiesenthal, K E; Suffet, I H

    2007-01-01

    A study of the production of odour-causing compounds was conducted from the leaching of polyvinylchloride (PVC) pipe and its joints, primer and cement, into drinking water distribution systems. Flavour Profile Analysis (FPA), closed-loop stripping analysis--gas chromatography/mass spectrometry (CLSA-GC/MS) and sensory-GC analysis of white or grey PVC alone found no odour-causing compounds produced during the leaching experiments. FPA analysis of the PVC's primer and cement leached alone and/or when applied to grey or white PVC pipes produced a glue/varnish odour. A sweet/phenolic odour replaced the glue/varnish odour after the leached media were diluted with Milli-Q water to threshold odour intensity. Three compounds were responsible for the sweet/phenolic odour and were observed by sensoryGC analysis. The leaching study of the PVC pipe with its joint solvents (primer and cement) concluded that the original solvent compounds, and their reaction products that formed during the bonding process on the PVC pipe, were a primary source of the glue/varnish odour. The original compounds of the PVC primer and cement were not detected by CLSA-GC/MS, due to their high volatility during the CLSA extraction method and/or these compounds appeared in a solvent peak of the GC/MS analysis. However, the original primer and cement chemicals (acetone, tetrahydrofuran, methyl ethyl ketone, and cyclohexanone) had a glue/varnish odour. A total of nine odorous GC peaks were produced as reaction products from leaching of primer in water and white or grey PVC pipe with primer and cement, and white or grey PVC with primer only. None of these compounds were among the chemical ingredients in the original primer or cement. Four GC peaks with a sweet/phenolic odour were present due to the reaction products of the cement leached with white or grey PVC. None of these compounds were positively identified. PMID:17489407

  13. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln.

    PubMed

    Bai, Y; Bao, Y B; Cai, X L; Chen, C H; Ye, X C

    2014-08-15

    The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production. PMID:25010454

  14. Importance of granulometry on phase evolution and phase-to-phase relationships of experimentally burned impure limestones intended for production of hydraulic lime and/or natural cement

    NASA Astrophysics Data System (ADS)

    Kozlovcev, Petr; Přikryl, Richard; Přikrylová, Jiřina

    2015-04-01

    In contrast to modern ordinary Portland cement production from finely ground raw material blends, ancient burning of hydraulic lime was conducted by burning larger pieces of natural raw material. Due to natural variability of raw material composition, exploitation of different beds from even one formation can result the product with significantly different composition and/or properties. Prague basin (Neoproterozoic to pre-Variscan Palaeozoic of the central part of the Bohemian Massif - the so-called Barrandian area, Czech Republic) represents a classical example of the limestone-rich region with long-term history of limestone burning for quick lime and/or various types of hydraulic binders. Due to the fact that burning of natural hydraulic lime has been abandoned in this region at the turn of 19th/20th c., significant gap in knowledge on the behavior of various limestone types and on the influence of minor variance in composition on the quality of burned product is encountered. Moreover, the importance of employment of larger pieces of raw material for burning for the development of proper phase-to-phase relationships (i.e. development of hydraulic phases below sintering temperature at mutual contacts of minerals) has not been examined before. To fill this gap, a representative specimens of major limestone types from the Prague basin have been selected for experimental study: Upper Silurian limestone types (Přídolí and Kopanina Lms.), and Lower Devonian limestones (Radotín, Kotýs, Řeporyje, Dvorce-Prokop, and Zlíchov Lms.). Petrographic character of the experimental material was examined by polarizing microscopy, cathodoluminescence, scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS), and X-ray diffraction (XRD) of insoluble residue. Based on the data from wet silicate analyses, modal composition of studied impure limestones was computed. Experimental raw material was burned in laboratory electric furnace at 1000 and 1200°C for 3 and/or 6 hours. Burned samples were examined by XRD for phase composition and by SEM-EDS for phase-to-phase relationships due to the burning. Based on our data it is evident that larnite-belite (dicalcium-silicate) is dominant phase in burned silica-rich limestones (represented by e.g. Dvorce-Prokop, Přídolí and/or Kopanina Lms.). In clay-rich limestones containing kaolinite and illite, gehlenite and other calcium aluminates and aluminosilicates were detected (represented by Kosoř, Řeporyje, and/or a portion of Dvorce-Prokop Lms.). Due to higher proportion of Fe-oxihydroxides in the Řeporyje Lms., brownmillerite (calcium aluminoferrite) forms as a typical minor phases during burning. Free-lime (plus its hydrated form - portlandite) makes dominant phase in limestones exhibiting low non-carbonate admixture (Kotýs and/or a portion of Kopanina Lms.). These results clearly demonstrate that presence of certain non-carbonate minerals governs formation of certain hydraulic phases in burned product, whilst mutual proportions of individual minerals in raw materials influence amount of newly formed phases.

  15. Low-cost process for hydrogen production

    DOEpatents

    Cha, C.H.; Bauer, H.F.; Grimes, R.W.

    1993-03-30

    A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen and carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

  16. Low-cost process for hydrogen production

    DOEpatents

    Cha, Chang Y. (Golden, CO); Bauer, Hans F. (Morgantown, WV); Grimes, Robert W. (Laramie, WY)

    1993-01-01

    A method is provided for producing hydrogen and carbon black from hydrocarbon gases comprising mixing the hydrocarbon gases with a source of carbon and applying radiofrequency energy to the mixture. The hydrocarbon gases and the carbon can both be the products of gasification of coal, particularly the mild gasification of coal. A method is also provided for producing hydrogen an carbon monoxide by treating a mixture of hydrocarbon gases and steam with radio-frequency energy.

  17. Image processing techniques for digital orthophotoquad production

    USGS Publications Warehouse

    Hood, Joy J.; Ladner, L. J.; Champion, Richard A.

    1989-01-01

    Orthophotographs have long been recognized for their value as supplements or alternatives to standard maps. Recent trends towards digital cartography have resulted in efforts by the US Geological Survey to develop a digital orthophotoquad production system. Digital image files were created by scanning color infrared photographs on a microdensitometer. Rectification techniques were applied to remove tile and relief displacement, thereby creating digital orthophotos. Image mosaicking software was then used to join the rectified images, producing digital orthophotos in quadrangle format.

  18. From Process to Product: Your Risk Process at Work

    NASA Technical Reports Server (NTRS)

    Kundrot, Craig E.; Fogarty, Jenifer; Charles, John; Buquo, Lynn; Sibonga, Jean; Alexander, David; Horn, Wayne G.; Edwards, J. Michelle

    2010-01-01

    The Space Life Sciences Directorate (SLSD) and Human Research Program (HRP) at the NASA/Johnson Space Center work together to address and manage the human health and performance risks associated with human space flight. This includes all human system requirements before, during, and after space flight, providing for research, and managing the risk of adverse long-term health outcomes for the crew. We previously described the framework and processes developed for identifying and managing these human system risks. The focus of this panel is to demonstrate how the implementation of the framework and associated processes has provided guidance in the management and communication of human system risks. The risks of early onset osteoporosis, CO2 exposure, and intracranial hypertension in particular have all benefitted from the processes developed for human system risk management. Moreover, we are continuing to develop capabilities, particularly in the area of information architecture, which will also be described. We are working to create a system whereby all risks and associated actions can be tracked and related to one another electronically. Such a system will enhance the management and communication capabilities for the human system risks, thereby increasing the benefit to researchers and flight surgeons.

  19. MAINTAINING SOIL PROCESSES FOR PLANT PRODUCTIVITY AND COMMUNITY DYNAMICS

    EPA Science Inventory

    Rangeland soil biota affect soil properties and processes that control the availability of water and nutrients that are essential for the maintenance of productivity and vegetation composition. oil processes mediated by soil biota include decomposition, nutrient immobilization an...

  20. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  1. ULTRA-LIGHTWEIGHT CEMENT

    SciTech Connect

    Fred Sabins

    2003-06-16

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). This report discusses testing that was performed for analyzing the alkali-silica reactivity of ULHS in cement slurries. Laboratory testing during the tenth quarter focused on evaluation of the alkali-silica reaction of eight different cement compositions, four of which contain ULHS. The original laboratory procedure for measuring set cement expansion resulted in test specimen erosion that was unacceptable. A different expansion procedure is being evaluated. This report provides a progress summary of ASR testing. The testing program initiated in November produced questionable initial results so the procedure was modified slightly and the testing was reinitiated. The results obtained with the modified procedure showed improvement over data obtained with the original procedure, but questionable data were obtained from several of the compositions. Additional modification of test procedures for compositions containing TXI Lightweight cement are being implemented and testing is ongoing.

  2. Separation processes during binary monotectic alloy production

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Facemire, B. R.; Kaukler, W. F.; Witherow, W. K.; Fanning, U.

    1984-01-01

    Observation of microgravity solidification processes indicates that outside of sedimentation, at least two other important effects can separate the phases: critical-point wetting and spreading; and thermal migration of second-phase droplets due to interfacial tension gradients. It is difficult to study these surface tension effects while in a unit gravity field. In order to investigate the processes occurring over a temperature range, i.e., between a consolute point and the monotectic temperature, it is necessary to use a low-gravity environment. The MSFC drop tube (and tower), the ballistic trajectory KC-135 airplane, and the Space Shuttle are ideal facilities to aid formation and testing of hypotheses. Much of the early work in this area focuses on transparent materials so that process dynamics may be studied by optical techniques such as photography for viewing macro-processes; holography for studying diffusional growth; spinodal decomposition and coalescence; ellipsometry for surface wetting and spreading effects; and interferometry and spectroscopy for small-scale spatial resolution of concentration profiles.

  3. Content, Process, and Product: Modeling Differentiated Instruction

    ERIC Educational Resources Information Center

    Taylor, Barbara Kline

    2015-01-01

    Modeling differentiated instruction is one way to demonstrate how educators can incorporate instructional strategies to address students' needs, interests, and learning styles. This article discusses how secondary teacher candidates learn to focus on content--the "what" of instruction; process--the "how" of instruction;…

  4. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, Rathin (Chicago, IL); Randhava, Sarabjit S. (Evanston, IL); Tsai, Shih-Perng (Naperville, IL)

    1997-01-01

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H.sub.2 O.sub.2 laden permeate.

  5. Process for the production of hydrogen peroxide

    DOEpatents

    Datta, R.; Randhava, S.S.; Tsai, S.P.

    1997-09-02

    An integrated membrane-based process method for producing hydrogen peroxide is provided comprising oxidizing hydrogenated anthraquinones with air bubbles which were created with a porous membrane, and then contacting the oxidized solution with a hydrophilic membrane to produce an organics free, H{sub 2}O{sub 2} laden permeate. 1 fig.

  6. Child Assessment: The Process and the Product.

    ERIC Educational Resources Information Center

    Hansen, Cheryl L., Ed.; Haring, Norris G., Ed.

    The document contains seven papers from the Child Assessment Topical Workshop designed to raise participant awareness of basic assessment issues involved in screening, placement, and measurement of daily performance; to provide specific information about the assessment process, including collecting, organizing, analyzing, and using data; and to…

  7. Content, Process, and Product: Modeling Differentiated Instruction

    ERIC Educational Resources Information Center

    Taylor, Barbara Kline

    2015-01-01

    Modeling differentiated instruction is one way to demonstrate how educators can incorporate instructional strategies to address students' needs, interests, and learning styles. This article discusses how secondary teacher candidates learn to focus on content--the "what" of instruction; process--the "how" of instruction;

  8. Process for the production of liquid hydrocarbons

    DOEpatents

    Bhatt, Bharat Lajjaram; Engel, Dirk Coenraad; Heydorn, Edward Clyde; Senden, Matthijis Maria Gerardus

    2006-06-27

    The present invention concerns a process for the preparation of liquid hydrocarbons which process comprises contacting synthesis gas with a slurry of solid catalyst particles and a liquid in a reactor vessel by introducing the synthesis gas at a low level into the slurry at conditions suitable for conversion of the synthesis gas into liquid hydrocarbons, the solid catalyst particles comprising a catalytic active metal selected from cobalt or iron on a porous refractory oxide carrier, preferably selected from silica, alumina, titania, zirconia or mixtures thereof, the catalyst being present in an amount between 10 and 40 vol. percent based on total slurry volume liquids and solids, and separating liquid material from the solid catalyst particles by using a filtration system comprising an asymmetric filtration medium (the selective side at the slurry side), in which filtration system the average pressure differential over the filtration medium is at least 0.1 bar, in which process the particle size distribution is such that at least a certain amount of the catalyst particles is smaller than the average pore size of the selective layer of the filtration medium. The invention also comprises an apparatus to carry out the process described above.

  9. Sweet sorghum processing for alcohol production

    SciTech Connect

    Schmulevich, I.; Coble, C.G.; Egg, R.P.

    1983-12-01

    Several processing techniques for producing ethanol from sweet sorghum were investigated. Fermentating chopped stalks yielded more ethanol than shredded sorghum or juice. Leaf removal prior to fermentation resulted in higher yields per unit feedstock. Removal of solids after fermentation yielded slightly more ethanol than solids removal before fermentation.

  10. From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

  11. From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete

  12. Processing maize flour and corn meal food products.

    PubMed

    Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

    2014-04-01

    Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn. PMID:24329576

  13. Processing maize flour and corn meal food products

    PubMed Central

    Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

    2014-01-01

    Corn is the cereal with the highest production worldwide and is used for human consumption, livestock feed, and fuel. Various food technologies are currently used for processing industrially produced maize flours and corn meals in different parts of the world to obtain precooked refined maize flour, dehydrated nixtamalized flour, fermented maize flours, and other maize products. These products have different intrinsic vitamin and mineral contents, and their processing follows different pathways from raw grain to the consumer final product, which entail changes in nutrient composition. Dry maize mechanical processing creates whole or fractionated products, separated by anatomical features such as bran, germ, and endosperm. Wet maize processing separates by chemical compound classification such as starch and protein. Various industrial processes, including whole grain, dry milling fractionation, and nixtamalization, are described. Vitamin and mineral losses during processing are identified and the nutritional impacts outlined. Also discussed are the vitamin and mineral contents of corn. PMID:24329576

  14. Set retarded cement compositions and well cementing methods

    SciTech Connect

    Childs, J.D.; Sabins, F.L.

    1986-04-15

    This patent describes a method of cementing a subterranean zone penetrated by a well bore comprising: providing a set retarded aqueous hydraulic cement slurry; admixing with the cement slurry to enhance the compressive strength development thereof after placement, an effective amount of a delayed retarder neutralizer selected from the group consisting of: a triethanolamine titanium chelate.

  15. Next generation enhancement of cements by the addition of industrial wastes and subsequent treatment with supercritical CO{sub 2}

    SciTech Connect

    Taylor, C.M.V.; Rubin, J.B.; Carey, J.W.; Jones, R.; Baglin, F.G.

    1997-09-01

    The natural curing reactions which occur in a standard portland cement involve the formation of portlandite, Ca(OH){sub 2}, and calcium silicate hydrates, CSH. Over time, the cured cement abstracts carbon dioxide, CO{sub 2}, from the air, converting the portlandite and CSH to calcium carbonate, CaCO{sub 3}. It turns out, however, that this secondary conversion results in the blockage and/or closure of pores, drastically slowing the reaction rate with time. By exposing a portland cement to supercritical CO{sub 2} (SCCO{sub 2}), it is found that the carbonation reaction can be greatly accelerated. This acceleration is due to (1) the ability of the supercritical fluid to penetrate into the pores of the cement, providing continuous availability of fresh reactant, in hyper-stoichiometric concentrations; and (2) the solubility of the reaction product in the supercritical fluid, facilitating its removal. By accelerating the natural aging reactions, a chemically stable product is formed having reduced porosity, permeability and pH, while at the same time significantly enhancing the mechanical strength. The supercritical CO{sub 2} treatment process also removes a majority of the hydrogenous material from the cement, and sequesters large amounts of carbon dioxide, permanently removing it from the environment. The authors describe the general features of supercritical fluids, as well as the application of these fluids to the treatment of cements containing industrial waste. Some of the issues concerning the economic feasibility of industrial scale-up will be addressed. Finally, some initial results of physical property measurements made on portland cements before and after supercritical fluid CO{sub 2} treatment will be presented.

  16. Process for Converting Waste Glass Fiber into Value Added Products, Final Report

    SciTech Connect

    Hemmings, Raymond T.

    2005-12-31

    Nature of the Event: Technology demonstration. The project successfully met all of its technical objectives. Albacem has signed an exclusive licensing agreement with Vitro Minerals Inc., a specialty minerals company, to commercialize the Albacem technology (website: www.vitrominerals.com). Location: The basic research for the project was conducted in Peoria, Illinois, and Atlanta, Georgia, with third-party laboratory verification carried out in Ontario, Canada. Pilot-scale trials (multi-ton) were conducted at a facility in South Carolina. Full-scale manufacturing facilities have been designed and are scheduled for construction by Vitro Minerals during 2006 at a location in the Georgia, North Carolina, and South Carolina tri-state area. The Technology: This technology consists of a process to eliminate solid wastes generated at glass fiber manufacturing facilities by converting them to value-added materials (VCAS Pozzolans) suitable for use in cement and concrete applications. This technology will help divert up to 250,000 tpy of discarded glass fiber manufacturing wastes into beneficial use applications in the concrete construction industry. This technology can also be used for processing glass fiber waste materials reclaimed from monofills at manufacturing facilities. The addition of take-back materials and reclamation from landfills can help supply over 500,000 tpy of glass fiber waste for processing into value added products. In the Albacem process, waste glass fiber is ground to a fine powder that effectively functions as a reactive pozzolanic admixture for use in portland ce¬ment-based building materials and products, such as concrete, mortars, terrazzo, tile, and grouts. Because the waste fiber from the glass manufacturing industry is vitreous, clean, and low in iron and alkalis, the resulting pozzolan is white in color and highly consistent in chemical composition. This white pozzolan, termed VCAS Pozzolan (for Vitreous Calcium-Alumino-Silicate). is especially suited for white concrete applications where it imparts desirable benefits such as increased long-term strength and improved long-term durability of concrete products. Two U.S. patents entitled have been issued to Albacem covering the technology. Third-party validation testing has confirmed that the pozzolanic product is an excellent, high performance material that conforms to a ASTM standards and improves the strength and durability of concrete. Currently, there are no known significant competing technologies to process glass fiber manufacturing by-products and con¬vert them into value-added products. Most glass fiber-forming and fabrication wastes continue to be disposed in landfills at significant costs and with associated negative environmental impact. It is estimated that in a typical glass fiber manufactur¬ing facility, 10-20% by weight of the processed glass material is sent for dis¬posal to a landfill. Today, supplementary ce¬menting materials or mineral admixtures are key to achieving strong and durable concrete. Recovered materials such as coal fly ash, ground granulated blast furnace slag and silica fume are widely accepted and used in concrete all over the world, espe¬cially in the construction of “high performance” structures such as massive dams, bridges, subway tunnels, etc. These min¬eral admixtures are not suitable for white concrete and light-colored architectural concrete applications. Converting waste glass fibers into a high performance white pozzolan would allow white concrete producers to gain from the same durability benefits currently realized by gray concrete producers. Description of the Benefit: Albacem’s technology will enable the glass fiber industry to eliminate nearly 100% of its glass fiber produc¬tion waste streams by converting them into viable value-added products. With this technology, the glass industry can prevent the landfilling of about 250,000 tons of waste glass fiber annually. Glass manufacturers will realize improved production efficiency by reducing process costs through the elimination of solid waste disposal costs and participation in revenue sharing for the creation of value-added market-ready products. Implementation of the technology will save a net amount of energy (estimated at 1.75-trillion BTU) consumed by eliminating the manufacture of material replaced by the processed waste glass. The technology also reduces the amount of CO2, NOx, and other air pollutants emitted from the manufacturer of the replaced product (Portland cement). In addition, jobs will be created, and the cement industry will benefit from the introduction of a new product that will increase the service life of concrete and improve sustainability.

  17. Global warming impact on the cement and aggregates industries

    SciTech Connect

    Davidovits, J. . Geopolymer Inst.)

    1994-06-01

    CO[sub 2] related energy taxes are focusing essentially on fuel consumption, not on actual CO[sub 2] emission measured at the chimneys. Ordinary Portland cement, used in the aggregates and industries, results from the calcination of limestone and silica. The production of 1 ton of cement directly generates 0.55 tons of chemical-CO[sub 2] and requires the combustion of carbon-fuel to yield an additional 0.40 tons of CO[sub 2]. The 1987 1 billion metric tons world production of cement accounted for 1 billion metric tons of CO[sub 2], i.e., 5% of the 1987 world CO[sub 2] emission. A world-wide freeze of CO[sub 2] emission at the 1990 level as recommended by international institutions, is incompatible with the extremely high cement development needs of less industrialized countries. Present cement production growth ranges from 5% to 16% and suggests that in 25 years from now, world cement CO[sub 2] emissions could equal 3,500 million tons. Eco-taxes when applied would have a spectacular impact on traditional Portland cement based aggregates industries. Taxation based only on fuel consumption would lead to a cement price increase of 20%, whereas taxation based on actual CO[sub 2] emission would multiply cement price by 1.5 to 2. A 25--30% minor reduction of CO[sub 2] emissions may be achieved through the blending of Portland cement with replacement materials such as coal-fly ash and iron blast furnace slag.

  18. Small-particle-size cement

    SciTech Connect

    Ewert, D.P.; Almond, S.W.; Blerhaus, W.M. II )

    1991-05-01

    Successful remedial cementing has historically been difficult in wells with large-interval, multizone, gravel-packed completions. The reason is the inability of conventional oilfield cements to penetrate gravel packs adequately. Small-particle-size cement (SPSC) was developed to penetrate gravel packs and to provide the zonal isolation required. This paper details the laboratory work, job design, and field implementation of this new cement.

  19. The Interaction between Central and Peripheral Processes in Handwriting Production

    ERIC Educational Resources Information Center

    Roux, Sebastien; McKeeff, Thomas J.; Grosjacques, Geraldine; Afonso, Olivia; Kandel, Sonia

    2013-01-01

    Written production studies investigating central processing have ignored research on the peripheral components of movement execution, and vice versa. This study attempts to integrate both approaches and provide evidence that central and peripheral processes interact during word production. French participants wrote regular words (e.g. FORME),…

  20. Product-Process Distinctions in ELT Curriculum Theory and Practice

    ERIC Educational Resources Information Center

    Wette, Rosemary

    2011-01-01

    ELT theory classifies curricula as belonging to one of two contrasting approaches: either process or product. While foundation-level teacher education literature offers strongly product-oriented advice, research- and theory-oriented texts stress the need to negotiate with learners, and to take language-learning processes into account. This article

  1. "Key Moments" as Pedagogical Windows into the Video Production Process

    ERIC Educational Resources Information Center

    Halverson, Erica; Gibbons, Damiana

    2010-01-01

    In this article, we trace learning across the digital video production process through case studies with four youth media arts organizations (YMAOs) across the United States. We hypothesize that what these organizations share is a series of key moments throughout the production process in which youth must articulate the relationship between the

  2. Analysis of process water use in poultry meat production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poultry processing facilities use large quantities of water for chiller unit operations. The chiller is critical for temperature reduction to inhibit microbial growth and preserve product quality and safety. Process water quality can also influence product safety when bacteria present on poultry sk...

  3. Nonperturbative multiphoton processes and electron-positron pair production

    SciTech Connect

    Hatsagortsyan, K. Z.; Mueller, C.; Keitel, C. H.

    2006-04-07

    Various regimes of pair production in laser fields are analyzed. Particularly, the question of the observability of pair production in a nonperturbative multiphoton regime is discussed. A simple heuristic method is employed which gives order-of-magnitude estimates for probabilities of multiphoton processes and allows to describe its main features. The method is initially probed upon the known process of pair production in a Coulomb and a strong laser field. Then it is applied to the nonperturbative multiphoton regime of the pair production process in a standing laser wave.

  4. Fe-containing phases in hydrated cements

    SciTech Connect

    Dilnesa, B.Z.; Wieland, E.; Lothenbach, B.; Dhn, R.; Scrivener, K.L.

    2014-04-01

    In this study synchrotron X-ray absorption spectroscopy (XAS) has been applied, an element specific technique which allows Fe-containing phases to be identified in the complex mineral mixture of hydrated cements. Several Fe species contributed to the overall Fe K-edge spectra recorded on the cement samples. In the early stage of cement hydration ferrite was the dominant Fe-containing mineral. Ferrihydrite was detected during the first hours of the hydration process. After 1 day the formation of Al- and Fe-siliceous hydrogarnet was observed, while the amount of ferrihydrite decreased. The latter finding agrees with thermodynamic modeling, which predicts the formation of Fe-siliceous hydrogarnet in Portland cement systems. The presence of Al- and Fe-containing siliceous hydrogarnet was further substantiated in the residue of hydrated cement by performing a selective dissolution procedure. - Highlights: Fe bound to ferrihydrite at early age hydration Fe found to be stable in siliceous hydrogarnet at longer term age hydration Fe-containing AFt and AFm phases are less stable than siliceous hydrogarnet. The study demonstrates EXAFS used to identify amorphous or poorly crystalline phases.

  5. New technology eliminates bulking in cementing operations

    SciTech Connect

    Anderson, J.W.; Buchanan, A.I.; Susanto, A.

    1996-12-31

    For years the drilling industry has wrestled with the problems associated with well cementing. The introduction of pneumatic bulk systems increased cement slurry mixing rates but accurate density control still eluded the experts. Many companies have introduced process controlled mixing systems but these are both expensive and not totally reliable. A new cementing system, that does not rely on bulking, has become available to the industry a storable oilwell cement slurry that can be kept in a liquid state indefinitely and made to set as and when required. Operators in Indonesia are now benefiting from this new technology. Slurries are mixed and tested to ensure they meet design specifications well before they are required on site. The {open_quotes}Base Slurry{close_quotes} or {open_quotes}Liquid Cement Premix{close_quotes} (LCP), which typically has a density of 16.0 pounds per gallon (ppg), is transported to the rig, diluted to produce the required density and pumped, ensuring a homogeneous slurry from start to finish.

  6. Ethanol and other products from citrus processing waste

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greater than 80 percent of citrus produced in Florida is processed for juice production. The bulk of this waste material is dried as citrus pulp and sold as a cattle feed by-product, often at a price lower than the cost of production. While not profitable, this does solve the problem of waste dispos...

  7. 9 CFR 381.306 - Processing and production records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Processing and production records. 381.306 Section 381.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF.... Container conveyor speed, and for agitating hydrostatic retorts, the rotative chain speed, shall...

  8. 9 CFR 318.306 - Processing and production records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Processing and production records. 318.306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... retort operation. Container conveyor speed, and for agitating hydrostatic retorts, the rotative...

  9. 9 CFR 381.306 - Processing and production records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Processing and production records. 381.306 Section 381.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF.... Container conveyor speed, and for agitating hydrostatic retorts, the rotative chain speed, shall...

  10. 9 CFR 318.306 - Processing and production records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Processing and production records. 318.306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... retort operation. Container conveyor speed, and for agitating hydrostatic retorts, the rotative...

  11. 9 CFR 381.306 - Processing and production records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Processing and production records. 381.306 Section 381.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF.... Container conveyor speed, and for agitating hydrostatic retorts, the rotative chain speed, shall...

  12. 9 CFR 318.306 - Processing and production records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Processing and production records. 318.306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... retort operation. Container conveyor speed, and for agitating hydrostatic retorts, the rotative...

  13. 9 CFR 318.306 - Processing and production records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Processing and production records. 318.306 Section 318.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... retort operation. Container conveyor speed, and for agitating hydrostatic retorts, the rotative...

  14. 9 CFR 381.306 - Processing and production records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Processing and production records. 381.306 Section 381.306 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF.... Container conveyor speed, and for agitating hydrostatic retorts, the rotative chain speed, shall...

  15. Lai Products and Validation For Hydrological Processes

    NASA Astrophysics Data System (ADS)

    Baret, Frdric; Combal, Bruno; Moulin, Sophie; Bacour, Cdric; Weiss, Marie; Garrigues, Sbastien

    Leaf area index (LAI) is a very important variable required in many hydrological processes. It controls evapotranspiration in several ways, rain interception and run- off. However, because LAI may change rapidly with space and time, estimates derived from remote sensing data could be used as input to spatially distributed hydrological models running at a range of scales. The derivation of LAI from remote sensing data is not straightforward since several factors may confound LAI effect on reflectance. We propose to use radiative transfer model inversion to estimate LAI from top of canopy reflectance measurements. Several inversion approaches are compared, with emphasis put on the regularisation of the inverse process by introducing prior information on the variables. Applications of this approach is made over several agricultural data sets at high spatial resolution (few 10th meters) thanks to hyperspectral (CASI, HYMAP) and BRDF (POLDER) airborne sensors. It includes the ReSeDA experiment on the Alpilles site in 1997 based on POLDER sensor, the Blue Earth experiment based on CASI in 1997, the DAISEX experiment in 1999 with POLDER and HYMAP and the Laon experiment based on CASI data in 2000 and 2001. The limitations of these approaches are discussed, with due attention on the way to derive prior information, inverse techniques, uncertainties on measurements and models, and scaling effects.

  16. Integrated coke, asphalt and jet fuel production process and apparatus

    DOEpatents

    Shang, Jer Y. (McLean, VA)

    1991-01-01

    A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.

  17. Differential Scanning Calorimetry Study of Ordinary Portland Cements Mixed with fly Ash and Slag

    NASA Astrophysics Data System (ADS)

    Al-Salami, A. E.; Ahmed, M. A.; Al-Hajry, A.; Taha, S.

    2005-03-01

    The study of the thermal behavior (DSC) of hydration products in ordinary Portland cement (OPC), as a function of water cement ratios (W/C) (0.2, 0.25, 0.4), and the partial substitution of (35 % fly ash), (35 % slag) and (35 % fly ash + 35 % slag) to the OPC system by weight separately was carried out. It was found that the additive materials (pozzlans) increase its durability when added to the OPC. The most important effects in the cement paste microstructure are the changes in pore structure produced by the reduction in the grain size caused by the pozzlanic reactions. The study revealed that the changes in all the thermal parameters depend on the variation of W/C ratios. The systematic changes in the activation energy through all systems occur at (0.3) W/C in the phase (C-H) and (0.35) W/C in the phase (C-S-H). This means that at these ratios of W/C the two phases (C-H) and (C-S-H) further accelerated the process of cement hydration reactions, and at the same time the addition to OPC system may provide enough space for hydration products to be distributed uniformly.

  18. A multistage process to enhance cellobiose production from cellulosic materials.

    PubMed

    Vanderghem, Caroline; Boquel, Pascal; Blecker, Christophe; Paquot, Michel

    2010-04-01

    Cellobiose, a disaccharide, is a valuable product that can be obtained from cellulose hydrolysis. In this study, a simple methodology is presented to enhance the production and improve the selectivity of cellobiose during enzymatic hydrolysis of cellulose. The approach consisted of a multistage removal of filtrate via vacuum filtration and resuspension of the retentate. By this process, the remaining solid was further hydrolyzed without additional enzyme loading. Compared to the continuous hydrolysis process, the production of cellobiose increased by 45%. Increased selectivity of cellobiose is due to the loss of beta-glucosidases in the filtrate, while enhanced productivity is likely due to mitigated product inhibition. PMID:19669625

  19. Cement Mason's Curriculum. Instructional Units.

    ERIC Educational Resources Information Center

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying

  20. Cement Mason's Curriculum. Instructional Units.

    ERIC Educational Resources Information Center

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  1. Product Binding Varies Dramatically between Processive and Nonprocessive Cellulase Enzymes*

    PubMed Central

    Bu, Lintao; Nimlos, Mark R.; Shirts, Michael R.; Ståhlberg, Jerry; Himmel, Michael E.; Crowley, Michael F.; Beckham, Gregg T.

    2012-01-01

    Cellulases hydrolyze β-1,4 glycosidic linkages in cellulose, which are among the most prevalent and stable bonds in Nature. Cellulases comprise many glycoside hydrolase families and exist as processive or nonprocessive enzymes. Product inhibition negatively impacts cellulase action, but experimental measurements of product-binding constants vary significantly, and there is little consensus on the importance of this phenomenon. To provide molecular level insights into cellulase product inhibition, we examine the impact of product binding on processive and nonprocessive cellulases by calculating the binding free energy of cellobiose to the product sites of catalytic domains of processive and nonprocessive enzymes from glycoside hydrolase families 6 and 7. The results suggest that cellobiose binds to processive cellulases much more strongly than nonprocessive cellulases. We also predict that the presence of a cellodextrin bound in the reactant site of the catalytic domain, which is present during enzymatic catalysis, has no effect on product binding in nonprocessive cellulases, whereas it significantly increases product binding to processive cellulases. This difference in product binding correlates with hydrogen bonding between the substrate-side ligand and the cellobiose product in processive cellulase tunnels and the additional stabilization from the longer tunnel-forming loops. The hydrogen bonds between the substrate- and product-side ligands are disrupted by water in nonprocessive cellulase clefts, and the lack of long tunnel-forming loops results in lower affinity of the product ligand. These findings provide new insights into the large discrepancies reported for binding constants for cellulases and suggest that product inhibition will vary significantly based on the amount of productive binding for processive cellulases on cellulose. PMID:22648408

  2. Product Binding Varies Dramatically between Processive and Nonprocessive Cellulase Enzymes

    SciTech Connect

    Bu, L.; Nimlos, M. R.; Shirts, M. R.; Stahlberg, J.; Himmel, M. E.; Crowley, M. F.; Beckham, G. T.

    2012-07-13

    Cellulases hydrolyze {beta}-1,4 glycosidic linkages in cellulose, which are among the most prevalent and stable bonds in Nature. Cellulases comprise many glycoside hydrolase families and exist as processive or nonprocessive enzymes. Product inhibition negatively impacts cellulase action, but experimental measurements of product-binding constants vary significantly, and there is little consensus on the importance of this phenomenon. To provide molecular level insights into cellulase product inhibition, we examine the impact of product binding on processive and nonprocessive cellulases by calculating the binding free energy of cellobiose to the product sites of catalytic domains of processive and nonprocessive enzymes from glycoside hydrolase families 6 and 7. The results suggest that cellobiose binds to processive cellulases much more strongly than nonprocessive cellulases. We also predict that the presence of a cellodextrin bound in the reactant site of the catalytic domain, which is present during enzymatic catalysis, has no effect on product binding in nonprocessive cellulases, whereas it significantly increases product binding to processive cellulases. This difference in product binding correlates with hydrogen bonding between the substrate-side ligand and the cellobiose product in processive cellulase tunnels and the additional stabilization from the longer tunnel-forming loops. The hydrogen bonds between the substrate- and product-side ligands are disrupted by water in nonprocessive cellulase clefts, and the lack of long tunnel-forming loops results in lower affinity of the product ligand. These findings provide new insights into the large discrepancies reported for binding constants for cellulases and suggest that product inhibition will vary significantly based on the amount of productive binding for processive cellulases on cellulose.

  3. Development of a Laboratory Cement Quality Analysis Apparatus Based on Laser-Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fan, Juanjuan; Zhang, Lei; Wang, Xin; Li, Yufang; Gong, Yao; Dong, Lei; Ma, Weiguang; Yin, Wangbao; Wang, Zhe; Li, Zheng; Zhang, Xiangjie; Li, Yi; Jia, Suotang

    2015-11-01

    Determination of the chemical composition of cement and ratio values of clinker plays an important role in cement plants as part of the optimal process control and product quality evaluation. In the present paper, a laboratory laser-induced breakdown spectroscopy (LIBS) apparatus mainly comprising a sealed optical module and an analysis chamber has been designed for possible application in cement plants for on-site quality analysis of cement. Emphasis is placed on the structure and operation of the LIBS apparatus, the sealed optical path, the temperature controlled spectrometer, the sample holder, the proper calibration model established for minimizing the matrix effects, and a correction method proposed for overcoming the ‘drift’ obstacle. Good agreement has been found between the laboratory measurement results from the LIBS method and those from the traditional method. The absolute measurement errors presented here for oxides analysis are within 0.5%, while those of ratio values are in the range of 0.02 to 0.05. According to the obtained results, this laboratory LIBS apparatus is capable of performing reliable and accurate, composition and proximate analysis of cement and is suitable for application in cement plants. supported by National Natural Science Foundation of China (Nos. 61127017, 61378047, 61205216, 61178009, 61108030, 61475093, and 61275213), the National Key Technology R&D Program of China (No. 2013BAC14B01), the 973 Program of China (No. 2012CB921603), the Shanxi Natural Science Foundation, China (Nos. 2013021004-1, 2012021022-1), and the Shanxi Scholarship Council of China (Nos. 2013-011 and 2013-01)

  4. Predicting seal effectiveness of cement-inflated packers

    SciTech Connect

    Sunman, G.O. Jr.; Wood, E.

    1995-05-01

    The use of cement for inflation of inflatable formation packers is desirable for many long-term applications. However, for cement-inflated formation packers (CIFPs) to provide a permanent seal, potential problems with cement bulk volume loss must bey properly understood and dealt with. Free water and particle segregation must be minimized and other bulk volume loss offset by properly dealing with elasticity and thermal expansion/contraction of pipe, cement, rubber and formation. Reasons for using cement, and effects and mitigation of free water and particle segregation are presented in this article. And a proprietary computer program developed by CTC International, called Bore seal, is introduced. This program provides a method of inflating CIFPs to retain the seal during future temperature and pressure changes in the wellbore, e.g., during stimulation or production/injection.

  5. Lightweight cementing program increases profit from Kansas oil field

    SciTech Connect

    McCalmont, A.J. ); Matthews, B.; Crook, R. )

    1992-06-29

    This paper reports that single-stage, lightweight cementing in a Kansas operation improved the cement bond across a permeable oil/water sand. Additionally, pipe movement after pumping helped bond quality by preventing the slurry from beginning its transition time. This delay allowed continued transmission of hydrostatic pressure against the formation. In 1991, OXY USA Inc. completed 12 wells in the Ray field in Kansas. All wells were drilled to the Reagan sand. The sand has a distinct water/oil contact, strong water drive, and good permeability. Because of poor cement bonding across the Reagan, two-stage conventional cementing in the first eight wells did not effectively prevent excessive water production. Some of these wells had to have remedial cement squeezes and be reperforated. This work increased completion costs by about $15,000/well.

  6. Radon emanation from concrete and the influence of using flyash in cement.

    PubMed

    van der Lugt, G; Scholten, L C

    1985-10-01

    In the Netherlands both Portland cement and blast furnace cement (slags from blast furnaces with about 30% Portland cement) are used for concrete. Radon exhalation measurements were carried out on concrete blocks made with these two types of cement and blocks with 15, 25 and 35% of the cement substituted by three different types of flyash. The results show that substituting part of the cement by flyash has no drastic effect on the exhalation rate. For concrete with Portland cement the exhalation rate decreases using flyash with an average radium content. With blast furnace cement a slight increase may be expected. The exhalation of concrete is greater than the sum of the exhalation values of the constituting components. The water in the pores of the concrete plays an essential role in the emanation process. PMID:3853271

  7. Process for production desulfurized of synthesis gas

    DOEpatents

    Wolfenbarger, James K.; Najjar, Mitri S.

    1993-01-01

    A process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content which comprises partially oxidizing said fuel at a temperature in the range of 1900.degree.-2600.degree. F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises a calcium-containing compound portion, a sodium-containing compound portion, and a fluoride-containing compound portion to produce a synthesis gas comprising H.sub.2 and CO with a reduced sulfur content and a molten slag which comprises (1) a sulfur-containing sodium-calcium-fluoride silicate phase; and (2) a sodium-calcium sulfide phase.

  8. Entropy production in oscillatory processes during photosynthesis.

    PubMed

    Lpez-Agudelo, Vctor A; Barragn, Daniel

    2014-01-01

    The flow of matter and heat and the rate of enzymatic reactions are examined using two models of photosynthesis that exhibit sustained and damped oscillatory dynamics, with the objective of calculating the rate of entropy generation and studying the effects of temperature and kinetic constants on the thermodynamic efficiency of photosynthesis. The global coefficient of heat transfer and the direct and inverse constants of the formation reaction of the RuBisCO-CO2 complex were used as control parameters. Results show that when the system moves from isothermal to non-isothermal conditions, the transition from a steady state to oscillations facilitates an increase in the energy efficiency of the process. The simulations were carried out for two photosynthetic models in a system on a chloroplast reactor scale. PMID:24162177

  9. Process for the production of maleic anhydride

    SciTech Connect

    Click, G.T.; Barone, B.J.

    1986-06-24

    A process is described for the vapor phase oxidation of hydrocarbons having 4 carbon atoms to produce maleic anhydride comprising contacting the hydrocarbons with a fixed bed vanadium-phosphorus-oxygen catalyst, containing P:V in an atomic ration of 1/2 to 3:1 whereby the catalyst gradually decreases in selectivity, wherein the improvement comprises contacting the catalyst with phosphorus compound of phosphorus halide, phosphorus oxyhalide, organic phospines, organic phosphites, organic phosphates or mixtures thereof at a temperature in the range of about 0/sup 0/ to 600/sup 0/C and thereafter contacting the catalyst with a flow of stream at a temperature in the range of 300/sup 0/ to 600/sup 0/C in an amount and for a sufficient duration whereby the catalyst is regenerated.

  10. Production process for advanced space satellite system cables/interconnects.

    SciTech Connect

    Mendoza, Luis A.

    2007-12-01

    This production process was generated for the satellite system program cables/interconnects group, which in essences had no well defined production process. The driver for the development of a formalized process was based on the set backs, problem areas, challenges, and need improvements faced from within the program at Sandia National Laboratories. In addition, the formal production process was developed from the Master's program of Engineering Management for New Mexico Institute of Mining and Technology in Socorro New Mexico and submitted as a thesis to meet the institute's graduating requirements.

  11. Set retarded cement compositions and methods for well cementing

    SciTech Connect

    Brothers, L.E.; Lindsey, D.W.; Terry, D.T.

    1990-07-17

    This patent describes a method of cementing a zone in a subterranean formation penetrated by a wellbore; It comprises: forming a pumpable set retarded cement slurry comprising hydraulic cement, fresh water, particulate silica having a particle size in the range of from about 0.02 to about 0.5 micron and a set retarder comprising a copolymer consisting essentially of 2-acrylamido, 2-methylpropane sulfonic acid (AMPS) and acrylic acid having an average molecular weight below about 5000 and comprising from about 40 to about 60 mole percent AMPS; pumping the cement slurry into the zone by way of the wellbore, and allowing the cement slurry to set therein.

  12. Primary cementing improvement by casing vibration during cement curing time

    SciTech Connect

    Cooke, C.E. Jr.; Gonzalez, O.J.; Broussard, D.J.

    1988-08-01

    Vibration of casing to improve primary cementing was investigated in the laboratory and in a 200-ft (60-m) deep test well. The effect of vibration is to decrease or to eliminate gel strength of the cement slurry as it is curing. The slurry then flows downward to compensate for shrinkage and re-establishes the hydrostatic head of the cement. This method can prevent pore-fluid entry into the annulus before the cement cures and can increase the radial stress at the interface between the formation and the cured cement.

  13. Development of fluidized bed cement sintering technology

    SciTech Connect

    Mukai, Katsuji

    1994-12-31

    In the new system presented in this paper, the cement clinker is sintered, not in a rotary kiln, but in two different furnaces: a spouted bed kiln and a fluidized bed kiln. The heat generated in the process of cooling the cement clinker is recovered by a fluidized bed cooler and a packed bed cooler, which are more efficient than the conventional coolers. Compared with the rotary kiln system, the new technology significantly reduces NO{sub x} emissions, appreciably cuts energy consumption, and reduces CO{sub 2} emissions as well. Thus, the new system is an efficient cement sintering system that is friendly to the global environment. In this paper, we describe this new technology as one of the applied technologies at an industrial level that is being developed in the Clean Coal Technology Project, and we present the results from test operations at our pilot plant.

  14. Quantifying microstructural variations in cement pastes: Implications on drying shrinkage

    NASA Astrophysics Data System (ADS)

    Garci, Maria Cecilia

    The objective of this research was to better understand the interrelationship between processing/composition, microstructure, and properties/performance in cement pastes. The most challenging aspect of this process is the investigation of microstructure. The primary hydration product in cement pastes, calcium silicate hydrate (C-S-H), has historically had an elusive chemistry and microstructure. It is generally accepted that both the microstructure and stoichiometry of this phase are variable and highly responsive to environmental changes. This sensitivity makes examination of C-S-H problematic. A method of examining the microstructure of cement pastes must meet two criteria. First, the method must be reproducible and sensitive to minute changes occurring in C-S-H. Second, it is desirable that the method be quantitative so as to facilitate correlation with processing variables and properties. With both of these criteria in mind, the nitrogen sorption method of measuring surface area and porosity was chosen for this investigation. Nitrogen sorption results have historically not been reproducible. This dilemma was approached first, and the effects of sample preparation were examined. Next, the surface area was manipulated using temperature and chemical admixtures. Finally, the effects of these variables on total, reversible, and irreversible drying shrinkage were examined. Results indicate that there are at least two types of C-S-H. One type has a high density (HD) while the other is less dense (LD). Nitrogen sorption measures only LD surfaces. Processing and chemical admixtures influence the ratio of the two types of C-S-H (LD/HD). Drying shrinkage results indicate that the greater the proportion of LD (as seen by higher nitrogen surface area), the greater the irreversible shrinkage.

  15. Hydration of alumina cement containing ferrotitanium slag with polycarboxylate-ethers (PCE) additives

    NASA Astrophysics Data System (ADS)

    Rechkalov, Denis; Chernogorlov, Sergey; Abyzov, Victor

    2016-01-01

    The paper is discussing results of study of alumina binder containing aluminous cement and ferrotitanium slag from aluminothermic process by Kliuchevskoi Ferroalloys corp. with various additives containing polycarboxylate-ethers (PCE). Selecting ferrotitanium slag as additive is based on the fact that its content of alumina and phase composition is closest to the alumina cement. The composition of the ferrotitanium slag is displayed. In order to compensate the decrease in strength caused by addition of ferrotitanium slag having low activity, PCE additives were added. As PCE additives were used Melflux 1641F, Melflux 2651F and Melflux PP200F by BASF. The effect of additives on the hydration of the binder, depending on the amount and time of additives hardening is shown. The composition of the hydration products in the cement was studied by physico-chemical analysis: derivatography and X-ray analysis. It is found that in the early stages of hardening PCE additives have inhibitory effect on hydration processes and promote new phase amorphization. The optimal content of additives was investigated. The basic properties of the binders have been tested. It was observed that the modified binders meet the requirements of Russian National State Standard GOST 969 to the alumina cement.

  16. Increase in the strength characteristics of Portland cement due to introduction of the compound mineral supplements

    NASA Astrophysics Data System (ADS)

    Il'ina, Liliia; Gichko, Nikolai; Mukhina, Irina

    2016-01-01

    At the initial phase of hardening it is the limestone component that plays a major role in the hardening process, which acts as the substrate for the crystallization of hydrate tumors due to its chemical affinity with the products of Portland cement hydration. After 7 days, the diopside supplement influences the processes more significantly. Diopside has a high modulus of elasticity compared to the cement paste. As a result, stresses are redistributed within the cement paste and the whole composition is hardened. An increase in the quantity of diopside in the compound supplement to more than 66.7% does not provide a substantial increase in the strength of the cement paste. As the hardness of diopside is higher than the hardness of limestone, much more energy is required to grind it down to a usable component. Therefore, a further increase in the quantity of diopside in the compound supplement is not economically feasible. An evaluation of the optimum quantity of input compound mineral supplements can be made based on the ideas of close packing of spherical particles and the Pauling rules. The optimum content of the supplement is 8-8.5% provided that its dispersion and density are close to the dispersion and density of the binder. An increase in the dispersion of the supplement reduces its optimal quantity.

  17. Process improvement exploration: mapping multimedia production process to CMMI-DEV

    NASA Astrophysics Data System (ADS)

    Lim, ChienWin; Kamaruddin, Noraida; Daud, Nor Izyani; Zainal Osman, Zosipha

    2013-03-01

    Multimedia takes improvement of multiple computing technologies to incorporate data from a wide variety of resources, without involving users to know how and where the data is encoded and stored. By reason of Multimedia applications interact with users with numerous diverse techniques and incorporate into strong applications that greatly extend the range and strength of applications, the production process are often complicated and complex. Production of such applications requires both process- and product-based quality assurance. Apparently, there are no universally accepted technical production standards. Consequently, Multimedia applications have sometimes diminished the quality of the end product, increased costs, delayed completion and failure. The focus is on the mapping between the current practices of multimedia production process and one of universal process improvement framework, Capability Maturity Model Integration for Development (CMMI-DEV). It shows that how current practices of multimedia production process address the Engineering Process Areas of CMMI-DEV. For each of the relevant process areas, it then explores how current practices can contribute to achieve the specific goals of that process area. This is practical for organizations that have their plan-driven process based on the CMMI-DEV model and are planning to improve the current practices of multimedia production process or to assist organization to define an innovative multimedia production process cycle based on CMMI-DEV practices.

  18. Retention of posts cemented with various dentinal bonding cements.

    PubMed

    Mendoza, D B; Eakle, W S

    1994-12-01

    This investigation evaluated the retention of preformed posts with four different cements: C & B Metabond, Panavia, All-Bond 2, and Ketac-Cem. Sixty intact maxillary canines were selected for the study. The clinical crowns were removed and endodontic therapy done on each root, which was then prepared to receive prefabricated posts. The 60 samples were divided into four groups of 15, and the posts in each group were cemented with one of the four cements. The roots were mounted in acrylic resin blocks and the posts were separated from the canals with an Instron testing machine. Analysis of the forces needed to dislodge the posts with analysis of variance and Student-Newman-Keuls test disclosed that C & B Metabond cement was the most retentive (p < 0.05). No difference in retention was recorded between Ketac-Cem and Panavia cements. All-Bond 2 cement was the least retentive of cements. PMID:7853255

  19. A practical approach to the interpretation of cement bond logs

    SciTech Connect

    Bigelow, E.L.

    1985-03-01

    The Cement Bond Log has been controversial since its inception. Despite its potential, it is possibly the most maligned logging service available to the industry. Effective zone isolation between permeable intervals in a well requires a cement sheath over an appreciable vertical interval. It is necessary for the annular cement sheath to provide an effective hydraulic seal in order to withstand subsequent completion and production operations. The oil industry has used wireline well logs to detect the presence or absence of cement behind pipe for more than twenty years. Users have attempted, not always successfully, to evaluate the effectiveness of cement bond to both pipe and formation, ostensibly, with Cement Bond Logs. Cement Bond Logs do not mislead. Poor interpretation habits mislead. Knowledge of the well completion and the inherent physical restraints placed upon the log measurements is needed in order to properly evaluate the log. The purpose here is to dispel some of the myths created by misguided interpretation practices. Examples of Cement Bond Logs which fall into this category are presented.

  20. A practical approach to the interpretation of cement bond logs

    SciTech Connect

    Bigelow, E.L.

    1985-07-01

    The cement bond log has been controversial since its inception. Despite its potential, it is possibly the most maligned logging service available to the industry. Effective zone isolation between permeable intervals in a well requires a cement sheath over an appreciable vertical interval. It is necessary for the annular cement sheath to provide an effective hydraulic seal to withstand subsequent completion and production operations. The oil industry has used wireline well logs to detect the presence or absence of cement behind pipe for more than 20 years. Users have attempted, not always successfully, to evaluate the effectiveness of cement bond to both pipe and formation with cement bond logs. Cement bond logs do not mislead. Poor interpretation habits mislead. Knowledge of the well completion and the inherent physical restraints placed on the log measurements is needed to evaluate the log properly. The purpose here is to dispel some of the myths created by misguided interpretation practices. Examples of cement bond logs that fall into this category are be presented.

  1. Curing time effect on the fraction of {sup 137}Cs from cement-ion exchange resins-bentonite clay composition

    SciTech Connect

    Plecas, Ilija; Dimovic, Slavko

    2007-07-01

    To assess the safety of disposal of radioactive waste material in cement, curing conditions and time of leaching radionuclides {sup 137}Cs have been studied. Leaching tests in cement-ion exchange resins-bentonite matrix, were carried out in accordance with a method recommended by IAEA. Curing conditions and curing time prior to commencing the leaching test are critically important in leach studies since the extent of hydration of the cement materials determines how much hydration product develops and whether it is available to block the pore network, thereby reducing leaching. Incremental leaching rates R{sub n}(cm/d) of {sup 137}Cs from cement ion exchange resins-bentonite matrix after 180 days were measured. The results presented in this paper are examples of results obtained in a 20-year concrete testing project which will influence the design of the engineer trenches system for future central Serbian radioactive waste storing center. (authors)

  2. Solid recovered fuels in the cement industry with special respect to hazardous waste.

    PubMed

    Thomanetz, Erwin

    2012-04-01

    Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other. PMID:22573713

  3. Study on Product Innovative Design Process Driven by Ideal Solution

    NASA Astrophysics Data System (ADS)

    Zhang, Fuying; Lu, Ximei; Wang, Ping; Liu, Hui

    Product innovative design in companies today relies heavily on individual members experience and creative ideation as well as their skills of integrating creativity and innovation tools with design methods agilely. Creative ideation and inventive ideas generation are two crucial stages in product innovative design process. Ideal solution is the desire final ideas for given problem, and the striving reaching target for product design. In this paper, a product innovative design process driven by ideal solution is proposed. This design process encourages designers to overcome their psychological inertia, to foster creativity in a systematic way for acquiring breakthrough creative and innovative solutions in a reducing sphere of solution-seeking, and results in effective product innovative design rapidly. A case study example is also presented to illustrate the effectiveness of the proposed design process.

  4. A non-linear model of economic production processes

    NASA Astrophysics Data System (ADS)

    Ponzi, A.; Yasutomi, A.; Kaneko, K.

    2003-06-01

    We present a new two phase model of economic production processes which is a non-linear dynamical version of von Neumann's neoclassical model of production, including a market price-setting phase as well as a production phase. The rate of an economic production process is observed, for the first time, to depend on the minimum of its input supplies. This creates highly non-linear supply and demand dynamics. By numerical simulation, production networks are shown to become unstable when the ratio of different products to total processes increases. This provides some insight into observed stability of competitive capitalist economies in comparison to monopolistic economies. Capitalist economies are also shown to have low unemployment.

  5. Fuzzy control of the production environment process parameters

    NASA Astrophysics Data System (ADS)

    Izvekov, V. N.

    2015-04-01

    The fuzzy control process for support of given microclimatic production environment process parameters with loss of one from values, regulating regime of process was shown. The structural schematic decisions with algorithm of functioning and oriented to existing apparatus (means of realization) was presented.

  6. Magnesium-phosphate-glass cements with ceramic-type properties

    DOEpatents

    Sugama, T.; Kukacka, L.E.

    1982-09-23

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  7. Magnesium phosphate glass cements with ceramic-type properties

    DOEpatents

    Sugama, Toshifumi; Kukacka, Lawrence E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  8. Magnesium phosphate glass cements with ceramic-type properties

    SciTech Connect

    Sugama, T.; Kukacka, L.E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono-and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  9. Hydration Characteristics of Metakaolin Admixtured Cement using DTA, XRD and SEM Techniques

    NASA Astrophysics Data System (ADS)

    Govindarajan, D.; Gopalakrishnan, R.

    2008-04-01

    The paper aims to investigate hydration and pozzolanic reaction in Portland cement paste with different replacement percentages (0%, 10%, 20% and 30%) of metakaolin. The compressive strength of the metakaolin admixtured cement was measured at 1 day, 1 week and 4 weeks. The compressive strength developments of the metakaolin admixtured cement are compared with Portland cement. It is found that metakaolin contributes significantly to strength development as an accelerating admixture for Portland cement. The pozzolanic reactions and the reaction products were determined by DTA, XRD and SEM.

  10. Modified-sulfur cements for use in concretes, flexible pavings, coatings, and grouts

    NASA Astrophysics Data System (ADS)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1981-05-01

    A family of modified-sulfur cements was developed for the preparation of construction materials with improved properties. Various types of sulfur cements were prepared by reacting sulfur with mixtures of dicyclopentadiene and oligomers of cyclopentadiene. Durable cements were prepared with structural characteristics ranging from rigid to flexible. These cements were used to prepare corrosion-resistant materials for use in a wide variety of industrial applications where resistance to acidic and salt conditions is needed. These materials were prepared as rigid concretes, flexible pavings, spray coatings, and grouts. Production of modified-sulfur cements in a commercial-size plant was demonstrated.

  11. Microstructure-controllable Laser Additive Manufacturing Process for Metal Products

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Chin; Chuang, Chuan-Sheng; Lin, Ching-Chih; Wu, Chih-Hsien; Lin, De-Yau; Liu, Sung-Ho; Tseng, Wen-Peng; Horng, Ji-Bin

    Controlling the cooling rate of alloy during solidification is the most commonly used method for varying the material microstructure. However, the cooling rate of selective laser melting (SLM) production is constrained by the optimal parameter settings for a dense product. This study proposes a method for forming metal products via the SLM process with electromagnetic vibrations. The electromagnetic vibrations change the solidification process for a given set of SLM parameters, allowing the microstructure to be varied via magnetic flux density. This proposed method can be used for creating microstructure-controllable bio-implant products with complex shapes.

  12. Cements with low Clinker Content

    NASA Astrophysics Data System (ADS)

    Garca-Lodeiro, I.; Fernndez-Jimnez, A.; Palomo, A.

    2015-11-01

    Hybrid alkaline cements are multi-component systems containing a high percentage of mineral additions (fly ash, blast furnace slag), low proportions (<30%) of Portland clinker and scarce amounts of alkaline activators. The substantially lower amount of clinker needed to manufacture these binders in comparison to ordinary Portland cement is both economically and ecologically beneficial. Their enormous versatility in terms of the raw materials used has made them the object of considerable interest. The present study explored the mechanical strength of binary blends mixes; B1= 20% clinker (CK) + 80% fly ash (FA) and B2=20% clinker + 80% blast furnace slag (BFS), both hydrated in the presence and absence of an alkaline activator specifically designed for this purpose. The use of the activator enhanced the development of early age strength considerably. All the hydrated matrices were characterised with XRD, SEM/EDX and (29Si and 27Al) NMR. The use of the alkaline activator generated reaction products consisting primarily of a mix of gels ((N,C)-A-S-H and C-A-S-H) whose respective proportions were found to depend upon system composition and initial reactivity.

  13. Technology for the product and process data base

    NASA Technical Reports Server (NTRS)

    Barnes, R. D.

    1984-01-01

    The computerized product and process data base is increasingly recognized to be the cornerstone component of an overall system aimed at the integrated automation of the industrial processes of a given company or enterprise. The technology needed to support these more effective computer integrated design and manufacturing methods, especially the concept of 3-D computer-sensible product definitions rather than engineering drawings, is not fully available and rationalized. Progress is being made, however, in bridging this technology gap with concentration on the modeling of sophisticated information and data structures, high-performance interactive user interfaces and comprehensive tools for managing the resulting computerized product definition and process data base.

  14. New cement formulation helps solve deep cementing problems

    SciTech Connect

    Brothers, L.E.; DeBlanc, F.X.

    1989-06-01

    Invert-emulsion muds are used in most deep, hot wells. The internal aqueous phase of these muds frequently contains high concentrations of salts. It is desirable to complete these wells with a cement slurry containing salt concentrations up to and including saturation to minimize compatibility problems between cement slurry and mud. Above their effective temperature range, however, saturated salt cements - though still considered desirable for their other properties - pose design difficulties regarding thickening time, fluid loss, and rheology. High salt concentrations tend to decrease the effectiveness of most common cement additives - e.g., retarders, fluid-loss additives, and dispersants. At high temperatures, concentrations of these additives can become unacceptably large, while the additives themselves are not as effective under these conditions. Development of and field experience with a new cementing formulation for deep, high-temperature, saturated-salt applications have helped resolve the cement design problems encountered in south Texas and southern and offshore Louisiana. A single synthetic-polymer additive provides cement retardation, fluid-loss control, and dispersant properties with normal design considerations as opposed to the lengthy design requirements of other cement systems. A particular benefit derived from use of the new cement system involves cementing of long liners. Such liners frequently require squeeze cementing at the liner top because the cement is designed for conditions at the bottom of the liner and is thus frequently over-retarded for the cooler temperatures encountered at the top of the liner. This over-retardation tendency is alleviated greatly by use of the new saturated-salt cement additive.

  15. MCFC integrated system in a biodiesel production process

    NASA Astrophysics Data System (ADS)

    Urbani, F.; Freni, S.; Galvagno, A.; Chiodo, V.

    2011-03-01

    The continuous increasing in biodiesel production by transesterification process is leading to an excess of glycerol production as a byproduct. The utilization of this huge amount of glycerol appears as a not easy solvable problem and thus several authors have proposed alternative ways. The integration of the main production process with a glycerol feed molten carbonate fuel cells bottoming cycle, to satisfy plant energy requirements, seems to be one of the most promising one. The proposed paper reports the main results obtained by authors in the framework of an investigation on a possible use of glycerol as energy sources for a real pilot plant for biodiesel production. An overall evaluation of worldwide biodiesel production plants was made and especially about the production capacity in European Union in the last decade. To make a more detailed study, authors were taken into account a real production plant. After a preliminary step, purported to plant mass and energy flows determination, authors considered the integration of a bottoming cycle based on: (i) steam reforming of glycerol for syn-gas production; (ii) molten carbonate fuel cells (MCFC) system supplied by syn-gas for heat and electricity production. A mathematical model, based on experimental data, has been developed to calculate mass and energy balances for the proposed plant lay-out as well as plant energy efficiency enhancement has been determined. Results have evidenced the feasibility of this process and demonstrated that plant integrated with bottoming cycle can reach a very high level of energy self-production.

  16. Automation and control of off-planet oxygen production processes

    NASA Technical Reports Server (NTRS)

    Marner, W. J.; Suitor, J. W.; Schooley, L. S.; Cellier, F. E.

    1990-01-01

    This paper addresses several aspects of the automation and control of off-planet production processes. First, a general approach to process automation and control is discussed from the viewpoint of translating human process control procedures into automated procedures. Second, the control issues for the automation and control of off-planet oxygen processes are discussed. Sensors, instruments, and components are defined and discussed in the context of off-planet applications, and the need for 'smart' components is clearly established.

  17. Energy Efficiency Improvement and Cost Saving Opportunities for Cement Making. An ENERGY STAR Guide for Energy and Plant Managers

    SciTech Connect

    Galitsky, Christina; Worrell, Ernst; Galitsky, Christina

    2008-01-01

    The cost of energy as part of the total production costs in the cement industry is significant, warranting attention for energy efficiency to improve the bottom line. Historically, energy intensity has declined, although more recently energy intensity seems to have stabilized with the gains. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Most recently, there is a slight increase in the use of waste fuels, including tires. Between 1970 and 1999, primary physical energy intensity for cement production dropped 1 percent/year from 7.3 MBtu/short ton to 5.3 MBtu/short ton. Carbon dioxide intensity due to fuel consumption and raw material calcination dropped 16 percent, from 609 lb. C/ton of cement (0.31 tC/tonne) to 510 lb. C/ton cement (0.26 tC/tonne). Despite the historic progress, there is ample room for energy efficiency improvement. The relatively high share of wet-process plants (25 percent of clinker production in 1999 in the U.S.) suggests the existence of a considerable potential, when compared to other industrialized countries. We examined over 40 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. The report describes the measures and experiences of cement plants around the wold with these practices and technologies. Substantial potential for energy efficiency improvement exists in the cement industry and in individual plants. A portion of this potential will be achieved as part of (natural) modernization and expansion of existing facilities, as well as construction of new plants in particular regions. Still, a relatively large potential for improved energy management practices exists.

  18. The Idaho Chemical Processing Plant Product Denitrator Upgrade

    SciTech Connect

    N /A

    1982-05-01

    The upgrade and redesign of a fluidized-bed denitrator for production of uranium trioxide from uranyl nitrate solution is discussed. The success of the project in improving process efficiency and personnel safety is also addressed based on subsequent operation.

  19. Contact damage failure analyses of fretting wear behavior of the metal stem titanium alloy-bone cement interface.

    PubMed

    Zhang, Lanfeng; Ge, Shirong; Liu, Hongtao; Wang, Qingliang; Wang, Liping; Xian, Cory J

    2015-11-01

    Although cemented titanium alloy is not favored currently in the Western world for its poor clinical and radiography outcomes, its lower modulus of elasticity and good biocompatibility are instrumental for its ability supporting and transforming physical load, and it is more suitable for usage in Chinese and Japanese populations due to their lower body weights and unique femoral characteristics. Through various friction tests of different cycles, loads and conditions and by examining fretting hysteresis loops, fatigue process curves and wear surfaces, the current study investigated fretting wear characteristics and wear mechanism of titanium alloy stem-bone cement interface. It was found that the combination of loads and displacement affected the wear quantity. Friction coefficient, which was in an inverse relationship to load under the same amplitude, was proportional to amplitudes under the same load. Additionally, calf serum was found to both lubricate and erode the wear interface. Moreover, cement fatigue contact areas appeared black/oxidative in dry and gruel in 25% calf serum. Fatigue scratches were detected within contact areas, and wear scars were found on cement and titanium surfaces, which were concave-shaped and ring concave/ convex-shaped, respectively. The coupling of thermoplastic effect and minimal torque damage has been proposed to be the major reason of contact damage. These data will be important for further studies analyzing metal-cement interface failure performance and solving interface friction and wear debris production issues. PMID:26241891

  20. Exclusive processes of charmonium production and charmonium wave functions

    SciTech Connect

    Braguta, V. V. Likhoded, A. K. Luchinsky, A. V.

    2012-01-15

    Results obtained by studying the properties of the leading-twist wave functions for the S- and P-wave states of charmonia are presented. Wave-function models that can be used to calculate various processes involving the production of these mesons were constructed on the basis of these investigations. Calculations for some exclusive processes of charmonium production were performed within the models in question.

  1. Recombinant Protein Production and Insect Cell Culture and Process

    NASA Technical Reports Server (NTRS)

    Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); OConnor, Kim C. (Inventor); Francis, Karen M. (Inventor); Andrews, Angela D. (Inventor); Prewett, Tracey L. (Inventor)

    1997-01-01

    A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using virtually infected or stably transformed insect cells containing a gene encoding the described polypeptide. The insect cells can also be a host for viral production.

  2. Recombinant protein production and insect cell culture and process

    NASA Technical Reports Server (NTRS)

    Spaulding, Glenn (Inventor); Prewett, Tacey (Inventor); Goodwin, Thomas (Inventor); Francis, Karen (Inventor); Andrews, Angela (Inventor); Oconnor, Kim (Inventor)

    1993-01-01

    A process has been developed for recombinant production of selected polypeptides using transformed insect cells cultured in a horizontally rotating culture vessel modulated to create low shear conditions. A metabolically transformed insect cell line is produced using the culture procedure regardless of genetic transformation. The recombinant polypeptide can be produced by an alternative process using the cultured insect cells as host for a virus encoding the described polypeptide such as baculovirus. The insect cells can also be a host for viral production.

  3. Membrane catalysis in the dehydrogenation and hydrogen production processes

    NASA Astrophysics Data System (ADS)

    Basov, N. L.; Ermilova, M. M.; Orekhova, N. V.; Yaroslavtsev, Andrei B.

    2013-04-01

    Data on the applications of membrane catalysis in the dehydrogenation of organic compounds and hydrogen production are analyzed and generalized. It is shown that the integration of membrane reactors into existing plants is necessary for production of hydrogen of high purity. The steam reforming and oxidative reforming of methane and steam reforming of light alcohols seem to be the most promising processes for hydrogen production in membrane reactors. The bibliography includes 165 references.

  4. PROCESS AND EQUIPMENT CHANGES FOR CLEANER PRODUCTION IN FEDERAL FACILITIES

    EPA Science Inventory

    The paper discusses process and equipment changes for cleaner production in federal facilities. During the 1990s, DoD and EPA conducted joint research and development, aimed at reducing the discharge of hazardous and toxic pollutants from military production and maintenance faci...

  5. 40 CFR 161.162 - Description of production process.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Description of production process. 161.162 Section 161.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data...

  6. 40 CFR 161.162 - Description of production process.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Description of production process. 161.162 Section 161.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data...

  7. 40 CFR 161.162 - Description of production process.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Description of production process. 161.162 Section 161.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data...

  8. Natural fiber production, harvesting, and preliminary processing: options and opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The utilization of natural fibers and plant oils in bio-products introduces numerous logistical challenges not typically encountered with non-agricultural resources. Once it has been determined that a plant material is suitable for commercial development, the production, harvesting, and processing s...

  9. NIR spectroscopy for determining soy contents in processed meat products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy products such as soy concentrate, soy protein and soy grits are used as a meat extender in processed meat products to improve meat texture. However, soy allergies are one of the common food allergies, especially in infants and young children, and can be mild to life-threatening. The United State...

  10. 40 CFR 161.162 - Description of production process.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Description of production process. 161.162 Section 161.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data...

  11. Exploring Group Communication and Productivity Improvement: Using an Experiential Process.

    ERIC Educational Resources Information Center

    Mandeville, Mary Y.; Mandeville, David E.

    Engineering students at Oklahoma State University used an experiential process (the ACME Basket Exercise) to develop an understanding of how quality and productivity can be improved. The exercise simulates a traditional production organization in the classroom and mirrors the efforts, the successes, and the frustrations of individuals and work

  12. Method of reducing fluid loss in cement compositions

    SciTech Connect

    Brothers, L.E.

    1989-02-21

    A method is described for cementing a conduit in a borehole penetrating an earthen formation by introducing a cementing composition into the space between the conduit and the formation, the cementing composition comprising: hydraulic content, an aqueous fluid, and a fluid-loss additive consisting essentially of a polymer reaction product of styrene with 2-acrylamido-2-methylpropanesulfonic acid and their salts, the styrene being present in the polymer in an amount of from about 15 to about 60 mole percent of the polymer.

  13. Impact of Wellbore Cement Degradation on CO2 Storage Integrity

    NASA Astrophysics Data System (ADS)

    Kutchko, B.; Strazisar, B.; Lowry, G.; Dzombak, D.; Thaulow, N.

    2007-12-01

    The sequestration of CO2 in underground geologic formations requires a thorough evaluation of potential leakage of the sequestered CO2 through the numerous existing wellbores which penetrate them. Leakage rates of less than 1% per 100 years have been deemed necessary for geologic sequestration to be viable. Well bores are of particular interest because the cement used to line and/or plug the well, may be vulnerable to acid attack. Injected CO2 will dissolve, becoming carbonic acid, which can readily react with calcium hydroxide and calcium silicate hydrate, key components in hardened cement. Laboratory experiments have been performed in order to determine the physical and chemical changes, as well as the rate of degradation of the cement under simulated sequestration reservoir conditions, including both aqueous and supercritical CO2. Upon exposure to aqueous CO2, hardened cement formed well-defined reaction zones by a 2-step process. The first step is the dissolution of Ca(OH) 2 (s) and subsequent precipitation of CaCO3 (s). The formation of CaCO3 (s) has been reported to decrease cement permeability and increase its compressive strength. The second step is the dissolution of CaCO3 (s) resulting in a leaching of calcium from the cement matrix. The resulting cement paste has a significant increase in porosity, is primarily composed of amorphous silica gel, and lacks structural integrity. Although it is clear that cement is degraded, the results of this study suggest that the reactions involved are slow. In fact, long term experiments show that the rate of degradation decreases over time, likely due to the precipitation of CaCO3 (s) within the pore space of the cement. This phenomenon should limit the negative impact that chemical degradation will have on well bores. Supercritical CO2 exposure (saturated with water vapor) led to a very different process by which CaCO3 (s) was deposited throughout the matrix and on the surface, rather than within an isolated reaction zone. Over the one-year time period of the experiments, this condition led to a smaller amount of total degradation than in the aqueous phase. However, in this case, there was no deceleration of the reaction observed. It is unlikely that the diffusion controlled degradation process observed in these experiments would lead to well failure in well completions that are well cemented with neat Portland cement (without additives). Further investigation is required to evaluate the effect of cement additives, fractures or channels in the cement, and geomechanical stress.

  14. Kinetics of cobalt cementation on zinc powder

    SciTech Connect

    Polcaro, A.M.; Palmas, S.; Dernini, S.

    1995-09-01

    The cementation process may be considered an interesting method to treat dilute solutions containing metal ions. The aim of the process may be either the removal of pollutant metals or the recovery of economically valuable metals such as Ag from spent photographic liquors. The kinetics of cobalt cementation on Zn powder from zinc sulfate concentrated solutions in the presence of copper and antimony ions was investigated in stirred tank reactors. The composition of the solutions was in the range usually utilized in industrial zinc electrowinning plants. The results showed that the reaction occurs by means of the formation of crystallization nuclei of noble metals on the zinc powder, followed by the cementation of cobalt ions on these newly-formed nuclei. Mass transfer to the reaction surface is shown to be the controlling step in copper and antimony reduction, and an equation correlating mass transfer coefficients has been determined. A kinetic equation, which interprets the influence of stirring speed and solution composition on cobalt cementation, has also been proposed.

  15. Mechanization and automation of production processes in turbine building

    NASA Astrophysics Data System (ADS)

    Slobodyanyuk, V. P.

    1984-02-01

    Specialists at the All-Union Institute of Planning and Technology of Energy Machine Building are working on the problem of mechanization and automation of production processes. One of the major technological processes being worked on is the production of welded units. At the present time the Institute has designed a centralized cutting and manufacturing shop in use at several metallurgical plants, clamping devices for materials hoists based on permanent magnets, a program controlled installation for driving shaped apertures in welded diaphragm rims and an automated system for planning technological processes involved in manufacturing operations. Even in the manufacture of such individualized devices as turbines, mechanization and automation of production processes are economically justified. During the 11th Five Year Plan, the Institute will continue to develop progressive technological processes and equipment for precise shaping of turbine blade blanks, mechanical working of parts of steam, gas and hydraulic turbines, as well as nuclear powerplant turbines.

  16. Mining manufacturing data for discovery of high productivity process characteristics.

    PubMed

    Charaniya, Salim; Le, Huong; Rangwala, Huzefa; Mills, Keri; Johnson, Kevin; Karypis, George; Hu, Wei-Shou

    2010-06-01

    Modern manufacturing facilities for bioproducts are highly automated with advanced process monitoring and data archiving systems. The time dynamics of hundreds of process parameters and outcome variables over a large number of production runs are archived in the data warehouse. This vast amount of data is a vital resource to comprehend the complex characteristics of bioprocesses and enhance production robustness. Cell culture process data from 108 'trains' comprising production as well as inoculum bioreactors from Genentech's manufacturing facility were investigated. Each run constitutes over one-hundred on-line and off-line temporal parameters. A kernel-based approach combined with a maximum margin-based support vector regression algorithm was used to integrate all the process parameters and develop predictive models for a key cell culture performance parameter. The model was also used to identify and rank process parameters according to their relevance in predicting process outcome. Evaluation of cell culture stage-specific models indicates that production performance can be reliably predicted days prior to harvest. Strong associations between several temporal parameters at various manufacturing stages and final process outcome were uncovered. This model-based data mining represents an important step forward in establishing a process data-driven knowledge discovery in bioprocesses. Implementation of this methodology on the manufacturing floor can facilitate a real-time decision making process and thereby improve the robustness of large scale bioprocesses. PMID:20416347

  17. Cement from magnesium substituted hydroxyapatite.

    PubMed

    Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

    2005-05-01

    Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements. PMID:15875256

  18. Integrating artificial and human intelligence into tablet production process.

    PubMed

    Gams, Matja; Horvat, Matej; Oek, Matej; Lutrek, Mitja; Gradiek, Anton

    2014-12-01

    We developed a new machine learning-based method in order to facilitate the manufacturing processes of pharmaceutical products, such as tablets, in accordance with the Process Analytical Technology (PAT) and Quality by Design (QbD) initiatives. Our approach combines the data, available from prior production runs, with machine learning algorithms that are assisted by a human operator with expert knowledge of the production process. The process parameters encompass those that relate to the attributes of the precursor raw materials and those that relate to the manufacturing process itself. During manufacturing, our method allows production operator to inspect the impacts of various settings of process parameters within their proven acceptable range with the purpose of choosing the most promising values in advance of the actual batch manufacture. The interaction between the human operator and the artificial intelligence system provides improved performance and quality. We successfully implemented the method on data provided by a pharmaceutical company for a particular product, a tablet, under development. We tested the accuracy of the method in comparison with some other machine learning approaches. The method is especially suitable for analyzing manufacturing processes characterized by a limited amount of data. PMID:24970587

  19. Mineral resource of the month: hydraulic cement

    USGS Publications Warehouse

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  20. Processing, quality and safety of irradiation - and high pressure processed meat and seafood products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past two decades, worldwide demands for meat and seafood products have increased dramatically due to the improved economical condition in many countries. To meet the demand, the producers have increased the production of meat and seafood products as well as applied new processing techniques t...

  1. Top-quark processes at NLO in production and decay

    SciTech Connect

    Campbell, John M.; Ellis, R.Keith

    2012-04-01

    We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top production, and t-channel single-top production into the product of an amplitude for production and an amplitude for decay. In this way we can retain all spin correlations. Both the production and the decay amplitudes are calculated consistently at next-to-leading order in alpha_s. The full dependence on the b-quark mass is also kept. Phenomenological results are presented for various kinematic distributions at the LHC and for the top quark forward-backward asymmetry at the Tevatron.

  2. Product and process effectiveness using performance-based auditing techniques

    SciTech Connect

    Horseman, M.L.

    1995-12-01

    Focus is the backbone of genius. Focus is the lifeblood of adequate products and effective processes. Focus is the theme of Performance-Based Audits (PBA). The Civilian Radioactive Waste Management (CRWM) Program is using the PBA tool extensively to focus on the evaluation of product adequacy and process effectiveness. The term Performance-Based Audit has been around for several years. however, the approach presented here for the systematic end-product selection, planning, and measurement of adequacy and effectiveness is new and innovative.

  3. Wet cement: a poorly recognized cause of full-thickness skin burns.

    PubMed

    Boyce, D E; Dickson, W A

    1993-10-01

    Cement is a rare cause of full-thickness burns. We have examined the aetiology, frequency and severity of these burns, and assessed public awareness of the potential of cement as a caustic agent. Of patients, 95 per cent were unaware of the potential of cement to cause burns, and none had seen precautionary warnings on cement bags or delivery dockets. Factors important in burn production appear to be alkalinity, duration of contact and the abrasive nature of the cement particles. It is concluded that doctors, especially casualty officers, should know of the potential of progressive full-thickness burns from wet cement. General public awareness should be increased. The cement manufacturers were asked to comment on the content of this paper. PMID:8288383

  4. Low energy production processes in manufacturing of silicon solar cells

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, A. R.

    1976-01-01

    Ion implantation and pulsed energy techniques are being combined for fabrication of silicon solar cells totally under vacuum and at room temperature. Simplified sequences allow very short processing times with small process energy consumption. Economic projections for fully automated production are excellent.

  5. Image processing system performance prediction and product quality evaluation

    NASA Technical Reports Server (NTRS)

    Stein, E. K.; Hammill, H. B. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

  6. Theoretical Issues in the Process-Product Controversy.

    ERIC Educational Resources Information Center

    de Beaugrande, Robert

    Diagramming composition as a control structure allows us to see the interaction between process and product and to discover that composition is not a linear process but starts and stops, returns and fixes, and moves ahead. In the interaction of three factors--the real world, the writer, and the reader--a text is produced. The objects, social

  7. 21 CFR 113.100 - Processing and production records.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Processing and production records. 113.100 Section 113.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY SEALED CONTAINERS Records and Reports §...

  8. 21 CFR 113.100 - Processing and production records.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Processing and production records. 113.100 Section 113.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY...

  9. 21 CFR 113.100 - Processing and production records.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Processing and production records. 113.100 Section 113.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY...

  10. 21 CFR 113.100 - Processing and production records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Processing and production records. 113.100 Section 113.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY...

  11. 21 CFR 113.100 - Processing and production records.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Processing and production records. 113.100 Section 113.100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION THERMALLY PROCESSED LOW-ACID FOODS PACKAGED IN HERMETICALLY...

  12. Identities and Beliefs in ESL Writing: From Product to Process

    ERIC Educational Resources Information Center

    Li, Xuemei

    2007-01-01

    Studies investigating cultural influences on second-language writing have been mainly product-oriented. Moreover, research on writing processes has mostly focused on the strategies of writing and learning to write. Writing processes where we can see the evolution of the writer's identity and beliefs have been less adequately addressed. Therefore,

  13. Ionic liquid-based green processes for energy production.

    PubMed

    Zhang, Suojiang; Sun, Jian; Zhang, Xiaochun; Xin, Jiayu; Miao, Qingqing; Wang, Jianji

    2014-11-21

    To mitigate the growing pressure on resource depletion and environment degradation, the development of green processes for the production of renewable energy is highly required. As a class of novel and promising media, ionic liquids (ILs) have shown infusive potential applications in energy production. Aiming to offer a critical overview regarding the new challenges and opportunities of ILs for developing green processes of renewable energy, this article emphasises the role of ILs as catalysts, solvents, or electrolytes in three broadly interesting energy production processes from renewable resources, such as CO2 conversion to fuels and fuel additives, biomass pretreatment and conversion to biofuels, as well as solar energy and energy storage. It is expected that this article will stimulate a generation of new ideas and new technologies in IL-based renewable energy production. PMID:24553494

  14. Fish Processed Production Planning Using Integer Stochastic Programming Model

    NASA Astrophysics Data System (ADS)

    Firmansyah, Mawengkang, Herman

    2011-06-01

    Fish and its processed products are the most affordable source of animal protein in the diet of most people in Indonesia. The goal in production planning is to meet customer demand over a fixed time horizon divided into planning periods by optimizing the trade-off between economic objectives such as production cost and customer satisfaction level. The major decisions are production and inventory levels for each product and the number of workforce in each planning period. In this paper we consider the management of small scale traditional business at North Sumatera Province which performs processing fish into several local seafood products. The inherent uncertainty of data (e.g. demand, fish availability), together with the sequential evolution of data over time leads the production planning problem to a nonlinear mixed-integer stochastic programming model. We use scenario generation based approach and feasible neighborhood search for solving the model. The results which show the amount of each fish processed product and the number of workforce needed in each horizon planning are presented.

  15. Image processing and products for the Magellan mission to Venus

    NASA Technical Reports Server (NTRS)

    Clark, Jerry; Alexander, Doug; Andres, Paul; Lewicki, Scott; Mcauley, Myche

    1992-01-01

    The Magellan mission to Venus is providing planetary scientists with massive amounts of new data about the surface geology of Venus. Digital image processing is an integral part of the ground data system that provides data products to the investigators. The mosaicking of synthetic aperture radar (SAR) image data from the spacecraft is being performed at JPL's Multimission Image Processing Laboratory (MIPL). MIPL hosts and supports the Image Data Processing Subsystem (IDPS), which was developed in a VAXcluster environment of hardware and software that includes optical disk jukeboxes and the TAE-VICAR (Transportable Applications Executive-Video Image Communication and Retrieval) system. The IDPS is being used by processing analysts of the Image Data Processing Team to produce the Magellan image data products. Various aspects of the image processing procedure are discussed.

  16. Process and product development in the manufacturing of molecular therapeutics.

    PubMed

    Atkinson, E M; Christensen, J R

    1999-08-01

    In the development of molecular therapies, a great deal of attention has focused on tissue targets, gene delivery vectors, and expression cassettes. In order to become an approved therapy, however, a molecular therapeutic has to pass down the same product registration pathway as any other biological product. Moving from research into industrial production requires careful attention to regulatory, manufacturing and quality concerns. Early work on developing and characterizing robust and scaleable manufacturing processes will ultimately be rewarded by ease of implementation as the product is successful in clinical trials. Regulatory agencies require solid process and product characterization studies to demonstrate control and understanding of the molecular therapeutic. As the gene therapy industry matures, standards will continue to rise, creating an industry that is capable of producing safe, high-quality and effective therapies for many of the world's most difficult disease targets. PMID:11713755

  17. Scale-down of the inactivated polio vaccine production process.

    PubMed

    Thomassen, Yvonne E; van 't Oever, Aart G; Vinke, Marian; Spiekstra, Arjen; Wijffels, Ren H; van der Pol, Leo A; Bakker, Wilfried A M

    2013-05-01

    The anticipated increase in the demand for inactivated polio vaccines resulting from the success in the polio eradication program requires an increase in production capacity and cost price reduction of the current inactivated polio vaccine production processes. Improvement of existing production processes is necessary as the initial process development has been done decades ago. An up-to-date lab-scale version encompassing the legacy inactivated polio vaccine production process was set-up. This lab-scale version should be representative of the large scale, meaning a scale-down model, to allow experiments for process optimization that can be readily applied. Initially the separate unit operations were scaled-down at setpoint. Subsequently, the unit operations were applied successively in a comparative manner to large-scale manufacturing. This allows the assessment of the effects of changes in one unit operation to the consecutive units at small-scale. Challenges in translating large-scale operations to lab-scale are discussed, and the concessions that needed to be made are described. The current scale-down model for cell and virus culture (2.3-L) presents a feasible model with its production scale counterpart (750-L) when operated at setpoint. Also, the current scale-down models for the DSP unit operations clarification, concentration, size exclusion chromatography, ion exchange chromatography, and inactivation are in agreement with the manufacturing scale. The small-scale units can be used separately, as well as sequentially, to study variations and critical product quality attributes in the production process. Finally, it is shown that the scale-down unit operations can be used consecutively to prepare trivalent vaccine at lab-scale with comparable characteristics to the product produced at manufacturing scale. PMID:23192424

  18. Self-tuning process monitoring system for process-based product

    SciTech Connect

    Hillaire, R.; Loucks, C.

    1998-02-01

    The hidden qualities of a product are often revealed in the process. Subsurface material damage, surface cracks, and unusual burr formation can occur during a poorly controlled machining process. Standard post process inspection is costly and may not reveal these conditions. However, by monitoring the proper process parameters, these conditions are readily detectable without incurring the cost of post process inspection. In addition, many unforeseen process anomalies may be detected using an advanced process monitoring system. This work created a process monitoring system for milling machines which mapped the forces, power, vibration, and acoustic emissions generated during a cutting cycle onto a 3D model of the part being machined. The hyperpoint overlay can be analyzed and visualized with VRML (Virtual Reality Modeling Language). Once the Process Monitoring System is deployed, detailed inspection may be significantly reduced or eliminated. The project deployed a Pro-Engineer to VRML model conversion routine, advanced visualization interface, tool path transformation with mesh generation routine, hyperpoint overlay routine, stable sensor array, sensor calibration routine, and machine calibration methodology. The technology created in this project can help validate production of WR (War Reserve) components by generating process signatures for products, processes, and lot runs. The signatures of each product can be compared across all products made within and across lot runs to determine if the processes that produced the product are consistently providing superior quality. Furthermore, the qualities of the processes are visibly apparent, since the part model is overlaid with process data. The system was evaluated on three different part productions.

  19. The JSC Engineering Directorate Product Peer Review Process

    NASA Technical Reports Server (NTRS)

    Jenks, Kenneth C.

    2009-01-01

    The JSC Engineering Directorate has developed a Product Peer Review process in support of NASA policies for project management and systems engineering. The process complies with the requirements of NPR 7120.5, NPR 7123.1 and NPR 7150.2 and follows the guidance in NASA/SP-2007-6105. This presentation will give an overview of the process followed by a brief demonstration of an actual peer review, with audience participation.

  20. Leaching from glass ionomer cements.

    PubMed

    Bapna, M S; Mueller, H J

    1994-09-01

    This study compared the electrical conductivities, pH and leached ion (F-, Ca, Al, Si) concentrations in supernatant liquids obtained from four glassionomer cements, a buffered ionomer cement, a polycarboxylate cement and a zinc phosphate cement, at three different levels of settings. The result indicated that the measured parameters are highest for the unset condition of cements and decreases as the set condition is approached, except for pH, which shows the opposite trend. Two pulp sensitive glassionomer cements, Chem Bond and Ketac Cem showed high Ca:F ratios as well as high Ca and F concentrations. Further, it is suggested that the cytotoxicity of leached F-, Si, Al and Zn at high concentration and at low pH may induce sensitivity in tooth structure. PMID:7996341