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1

STAGE MULTI----SITE AGGREGATE PRODUCTION AND SITE AGGREGATE PRODUCTION AND SITE AGGREGATE PRODUCTION AND SITE AGGREGATE PRODUCTION AND DISTRIBUTION PLANNING MODEL FOR A CONTINUOUS DISTRIBUTION PLANNING MODEL FOR A CONTINUOUS DISTRIBUTION PLANNING MODEL FOR A CONTINUOUS DISTRIBUTION PLANNING MODEL FOR A CONTINUOUS CEMENT MANUFACTURING PROCESS CEMENT MANUFACTURING PROCESS CEMENT MANUFACTURING PROCESS CEMENT MANUFACTURING PROCESS  

Microsoft Academic Search

Abstract: Abstract: Abstract: Production planning is an important activity in process companies, since it deals with production resources (work-force and production capacity) dimensioning and inventory management. This paper presents an Aggregate Production and Distribution Planning (APDP) model for cement industry to help managers to evaluate the need and the relevance of integrate production and distribution decisions. The Mixed Integer Linear

Luiz Otavio; Zavalloni Proto; Marco Aurélio de Mesquita

2

Well cementing process  

Microsoft Academic Search

This is a method of cementing a pipe by jetting a slurry of cement against the well bore wall while continuously moving the pipe in the well bore. After a jetting tool is placed on the drill pipe, tubing, casing, first string of multiple casing settings or other pipe, it is then positioned below the deepest possible production zone in

Havens

1968-01-01

3

Inspecting rotating kilns used in cement production: line IR scanners and data processing  

NASA Astrophysics Data System (ADS)

The paper will describe the parameters of the IR systems used for inspecting the quality of thermal insulation in rotating kilns used in cement production. The systems are provided with a laser targeting device and a remote radio control device. They include: an 'Introcon-05' IR scanner, a laptop PC, an adapter of the communication line, a synchro-unit and a 'Thermoinspector' software. The latter one allows data filtering and thresholding in order to indicate defect zones. The built-in defect characterization algorithm enables estimates of a residual thickness of the thermal insulation layer. The systems are being used by several Russian producers of cement.

Torgunakov, Vladimir G.; Vavilov, Vladimir P.

2003-04-01

4

Wet process rotary cement kilns: modeling and simulation  

Microsoft Academic Search

The knowledge of wet process kilns design and operation in the cement industry has not been improved substantially during the last decades since the pre-calcination process has been developed to become the technological standard. In spite of the tendency to replace wet process rotary kilns for cement production by modern dry process kilns with pre-calcination, there are still a substantial

F. Mintus; S. Hamel; W. Krumm

2006-01-01

5

[Environment load from China's cement production].  

PubMed

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

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

2006-10-01

6

Optimization and characterization of a cemented ultimate-storage product  

NASA Astrophysics Data System (ADS)

The U- and Pu-containing packaging wastes can be homogeneously cemented after a washing and fragmentation process. Both finely crushed and coarsely fragmented raw wastes yield products with sufficient mechanical stability. The processability limit of the coarsely fragmented raw waste using cement paste or mortar is largely determined by the cellulose content, which is not to exceed 1.3% by weight in the end waste. Of 9 binders studied, the most corrosion-resistant products were obtained with blast-furnace slag cement, whereas poured concrete and Maxit are much less resistant in five-component brine. In the cemented product, hydrolysis of plasticizers (DOP) from plastics (PVC) occurs, leading to release of 2-ethyl-hexanol. This reaction occurs to a much lower degree with blast-furnace slag cement than with all other binders studied. The binder chosen for further tests consists of blast-furnace slag cement, concrete fluidizer and a stabilizer, and is processed at a W/C ratio of 0.43.

Brunner, H.

1981-12-01

7

Multi-performance optimization of cement blending process  

Microsoft Academic Search

In order to effectively solve the blending optimization problem in cement production process, an optimization model integrating production indices, the cost and its solution method are provided. Firstly, the cost and the rate values of raw materials are incorporated into the optimization model respectively as the objective function. Penalty function is used to transform optimization problem with constraints into an

Junli Li; Jianlin Mao; Guanghui Zhang

2011-01-01

8

Process for cementing geothermal wells  

DOEpatents

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.

Eilers, Louis H. (Inola, OK)

1985-01-01

9

Characterization of cement minerals, cements and their reaction products at the atomic and nano scale   

E-print Network

Recent advances and highlights in characterization methods are reviewed for cement minerals, cements and their reaction products. The emphasis is on X-ray and neutron diffraction, and on nuclear magnetic resonance methods, although X-ray absorption...

Skibsted, Joergen; Hall, Christopher

10

CONSTRUCTION-GRADE CEMENT PRODUCTION FROM CONTAMINATED SEDIMENTS USING  

E-print Network

1 CONSTRUCTION-GRADE CEMENT PRODUCTION FROM CONTAMINATED SEDIMENTS USING CEMENT-LOCKTM TECHNOLOGY A developed the Cement-LockTM Technology a versatile, cost-effective, and environmentally friendly manufacturing technology for producing construction-grade cements from a wide variety of contaminated waste

Brookhaven National Laboratory

11

Modeling and control of cement grinding processes  

Microsoft Academic Search

In this study, a nonlinear dynamic model of a cement grinding process, including a ball mill and an air separator in closed loop, is developed. This gray-box model consists of a set of algebraic and partial differential equations containing a set of unknown parameters. The selection of a model parametrization, the design of experiments, the estimation of unknown parameters from

Michaël Boulvin; Alain Vande Wouwer; Renato Lepore; Christine Renotte; Marcel Remy

2003-01-01

12

THE PULTRUSION TECHNOLOGY FOR THE PRODUCTION OF FABRIC-CEMENT  

E-print Network

THE PULTRUSION TECHNOLOGY FOR THE PRODUCTION OF FABRIC-CEMENT COMPOSITES Alva Peled Structural Engineering, Arizona State University, USA #12;Advantages of Fabrics in Cement Composites 0 300 600 900 0 2 4 6 8 Deflection, mm FlexuralLoad,N Fabrics Continuous Fibers Cement Matrix #12;Fabrics

Mobasher, Barzin

13

Microscale investigation of arsenic distribution and species in cement product from cement kiln coprocessing wastes.  

PubMed

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

Yang, Yufei; Xue, Jingchuan; Huang, Qifei

2013-01-01

14

Utilization of red mud in cement production: a review.  

PubMed

Red mud is a solid waste residue of the digestion of bauxite ores with caustic soda for alumina production. Its disposal remains a worldwide issue in terms of environmental concerns. During the past decades, extensive work has been done by a lot of researchers to develop various economic ways for the utilization of red mud. One of the economic ways is using red mud in cement production, which is also an efficient method for large-scale recycling of red mud. This paper provides a review on the utilization of red mud in cement production, and it clearly points out three directions for the use of red mud in cement production, namely the preparation of cement clinkers, production of composite cements as well as alkali-activated cements. In the present paper, the chemical and mineralogical characteristics of red mud are summarized, and the current progresses on these three directions are reviewed in detail. PMID:21930526

Liu, Xiaoming; Zhang, Na

2011-10-01

15

Productivity increase of the vertical roller mill for cement grinding  

Microsoft Academic Search

The specific power consumption, product quality and other performance of the “OK” and “CK” vertical roller mills for cement grinding are briefly stated. Hence, the enhancement in increasing the productivity of the vertical roller mill at Chichibu Onoda Cement Corporation (COCC) is introduced. These include: (a) restoring a table liner and roller tires by hard-facing to reduce maintenance costs; (b)

M. Ito; K. Sato; Y. Naoi

1997-01-01

16

Sustainable cement production-present and future  

SciTech Connect

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.

Schneider, M., E-mail: sch@vdz-online.de [VDZ, Duesseldorf (Germany); Romer, M.; Tschudin, M. [Holcim Group Support Ltd, Holderbank (Switzerland); Bolio, H. [CEMEX, Monterrey (Mexico)

2011-07-15

17

Energy, environmental and greenhouse gas effects of using alternative fuels in cement production  

E-print Network

1 Energy, environmental and greenhouse gas effects of using alternative fuels in cement-sponsored by #12; 2 EXECUTIVE SUMMARY Cement is by far the most widely used man-made material. The global cement industry produces about 3.3 billion tonnes of cement annually. Cement production is energy

Columbia University

18

Carbonation of cement-based products with pure carbon dioxide and flue gas.  

E-print Network

??CO2 absorption behaviour of four commonly used cement based building products: cement paste, concrete block, expanded polystyrene bead (EPB) and cement-bonded cellulose fiberboard are studied.… (more)

Wang, Sanwu, 1971-

2007-01-01

19

The Impact of Mathematical Modeling on the Production of Special Purpose Cement  

E-print Network

The Impact of Mathematical Modeling on the Production of Special Purpose Cement Domenico Lahaye in the production industry? Our partnership with Almatis B.V., a special purpose cement manufacturer, resulted with experts in various engineering disciplines. Production of Special Purpose Cement Commonly used cement

Vuik, Kees

20

Cementation process for minerals recovery from Salton Sea geothermal brines  

SciTech Connect

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.

Maimoni, A.

1982-01-26

21

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

PubMed

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

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

2014-02-18

22

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

Federal Register 2010, 2011, 2012, 2013, 2014

...and Production Act of 1993--Portland Cement Association Notice is hereby given that...et seq. (``the Act''), Portland Cement Association (``PCA'') has filed...to this venture. Also, Texas-Lehigh Cement Company, Buda, TX; Arizona Cement...

2012-02-03

23

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

SciTech Connect

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.

Wagner, J.C. [Institute of Gas Technology, Chicago, IL (United States); Bhatty, J.I.; Mishulovich, A. [Construction Technology Labs., Inc., Washington, DC (United States)

1995-12-31

24

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

Federal Register 2010, 2011, 2012, 2013, 2014

...TA-W-72,048] FLSMidth, Inc., Cement Division, Product Engineering, Including...applicable to workers of FLSmidth, Inc., Cement Division, Product Engineering, including...employed on-site at FLSmidth, Inc., Cement Division, Product Engineering,...

2010-01-05

25

Properties and hydration products of lightweight and expansive cements. Part II: Hydration products  

SciTech Connect

The type and quantity of hydration products in cement stone (plain cement, lightweight cement with cenospheres, and cement mixed with expansive additive) hydrated at 20 and 75 C were studied. The changes in the cement stone structure under the influence of lightweight and expansive additives and raised hardening temperature were studied with complex thermal analysis, infrared spectroscopy, powder X-ray diffraction analysis, and scanning electron microscopy. In the case of raised hardening temperature, the cenospheres and the expansive additive improve the crystallization of hydration products. A chemical reaction between the cenospheres and portlandite formed from the cement hydration was observed, accompanied by a decrease of the portlandite quantity. The expansive additive stimulates the formation of hydration products, which were thermally stable and decompose at temperatures above 600 C.

Lilkov, V.; Djabarov, N.; Bechev, G.; Petrov, O.

1999-10-01

26

Formulation of criteria for pollution control on cement products produced from solid wastes in China.  

PubMed

The process of producing cement products from solid waste can increase the level of pollutants in the cement products. Therefore, it is very important to establish a pollution control standard for cement products to protect the environment and human health. This paper presents acceptance limits for the availability of heavy metals in cement products which have been produced from solid wastes and explains how the limits have been calculated. The approach and method used to formulate these criteria were based on EN 12920. The typical exposure scenarios used in this paper involve concrete being used for drinking water supply pipelines and concrete pavements and are based on an analysis of typical applications of cement in China, and the potential for contact with water. The parameters of a tank test which was based on NEN 7375 were set in accordance with the environmental conditions of typical scenarios in China. Mechanisms controlling the release of heavy metals in concrete and a model for that release were obtained using the leaching test. Finally, based on acceptance criteria for drinking water and groundwater quality in China, limit values for the availability of heavy metals in concrete were calculated. PMID:21514989

Yang, Yufei; Huang, Qifei; Yang, Yu; Huang, Zechun; Wang, Qi

2011-08-01

27

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

SciTech Connect

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.

Schumacher, Katja; Sathaye, Jayant

1999-07-01

28

Recycling Coal Gangue as Raw Material for Portland Cement Production in Dry Rotary Kiln  

Microsoft Academic Search

Coal gangue (CG) is one of industrial solid wastes with biggest discharging. The disposal of such a large quantity of this solid waste requires lots of land and many serious environmental problems have been occurred. In this paper, CG as one of cement raw materials, and production experiments were performed in a 5000t-d-1 dry process rotary kiln to calcinations Portland

Guohua Qiu; Weiqiang Zeng; Zhenglun Shi; Leming Cheng; Zhongyang Luo

2010-01-01

29

Experiences with the design of large size cement plants - Process and layout considerations in pyroprocess systems  

Microsoft Academic Search

The important task to update production process by means of latest technological developments must be accomplished by both the equipment supplier and the cement producer. The equipment supplier, being the technological partner to the industry can thus help greatly to stay competitive in the changing face of the industry. Off late due to the rapid growth rate of Indian economy

A. K. Dembla; M. Mersmann

2007-01-01

30

Glass recycling in cement production--an innovative approach.  

PubMed

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

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

2002-01-01

31

Influence of the processed sunflower oil on the cement properties  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

32

Evaluation of cement production using a pressurized fluidized-bed combustor  

SciTech Connect

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.

DeLallo, M.; Eshbach, R.

1994-01-01

33

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

Federal Register 2010, 2011, 2012, 2013, 2014

...and Production Act of 1993; Portland Cement Association Notice is hereby given that...et seq. (``the Act''), Portland Cement Association (``PCA'') has filed...specified circumstances. Specifically, Drake Cement, LLC, Scottsdale, AZ; Argos USA...

2011-06-13

34

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

Federal Register 2010, 2011, 2012, 2013, 2014

...and Production Act of 1993--Portland Cement Association Notice is hereby given that...et seq. (``the Act''), Portland Cement Association (``PCA'') has filed...circumstances. Specifically, Continental Cement, Hannibal, MO has been added as a...

2010-01-27

35

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

Federal Register 2010, 2011, 2012, 2013, 2014

...and Production Act of 1993--Portland Cement Association Notice is hereby given that...et seq. (``the Act''), Portland Cement Association (``PCA'') has filed...Metso Minerals, York, PA; Lehigh Cement Company LLC, Allentown, PA;...

2011-03-07

36

Alkaline stability of cellulose ethers and impact of their degradation products on cement hydration  

E-print Network

1 Alkaline stability of cellulose ethers and impact of their degradation products on cement-mail address: pourchez@emse.fr emse-00449712,version1-18Sep2010 Author manuscript, published in "Cement the potential role of cellulose ethers degradation on the alteration of the cement hydration kinetics

Paris-Sud XI, Université de

37

Superplasticized portland cement: production and compressive strength of mortars and concrete  

Microsoft Academic Search

This paper deals with the effect of intergrinding different percentages of a naphthalene-based superplasticizer with Portland cement clinker and gypsum on the fineness of the product, and on the water requirement and the compressive strength of the mortars made with the superplasticized cement. The properties of the fresh and hardened concrete made with the superplasticized cements were also investigated. The

N. Bouzoubaa; M. H. Zhang; V. M. Malhotra

1998-01-01

38

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

E-print Network

cement production process are (Stockholm Convention 2006): ? the main burner at the rotary kilncement production. Figure 4 shows the temperature profile at different points in a rotary kilncement production are associated with calcination during clinker production. Once the clinker is formed in the rotary kiln,

Hasanbeigi, Ali

2013-01-01

39

Effect of burning supplementary waste fuels on the pollutant emissions by cement plants: a statistical analysis of process data  

Microsoft Academic Search

This paper shows how some statistical tools can be applied in the process analysis of real plant data, e.g. in the clinker production process by using alternative fuels (shredded tyres and waste oils) as alternative fuels in clinker kilns of two different cement plants. Statistical Student's t-tests, stepwise linear regression models and factor analysis were employed in the data analysis

M. Prisciandaro; G. Mazziotti; F. Veglió

2003-01-01

40

Study of cement apparatus, cement production and transportation in adult male Neoechinorhynchus rutili (Acanthocephala, Eoacanthocephala).  

PubMed

Investigation with light and electron microscopy has been made of the cement apparatus of the mature male Neoechinorhynchus rutili, a parasite of Gasterosteus aculeatus. N. rutili possesses a single compact mass of glandular tissue (cement gland) with eight giant nuclei. The nucleus is lobe-shaped and has a conspicuous nucleolus with a granular appearance. The cytoplasm of the gland contains prominent rough endoplasmic reticulum, mitochondria and electron dense secretory granules. A short duct connects the gland with a single, separate cement reservoir. The duct appears to lack a lumen and is seen as an electron-dense, compact structure. Many microtubules of approximately 150 nm outer diameter are located throughout the cytoplasm of the duct. It is proposed that the microtubules in N. rutili are responsible for the transport of cement granules from the gland to the reservoir. The cement reservoir appears as a compact organ filled with granules measuring at least 0.5 microm in diameter. PMID:11068810

Dezfuli, B S

2000-10-01

41

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...

42

Recent developments in the lime-fly ash process for alumina and cement  

Microsoft Academic Search

Recent developments from research of the limestone-fly ash sinter process for the extraction of alumina from coal fly ash and use of the residue in the manufacture of portland cement may result in substantial reductions in processing costs. It has been found that cement kiln dust can be used in place of limestone, and that the addition of coal refuse

M. J. Murtha; G. Burnet

1981-01-01

43

Investigative and management techniques for cement kiln dust and pulp and paper process wastes  

Microsoft Academic Search

Knowledge of the characteristics of industrial process wastes allows for some innovative and cost savings techniques for investigating and managing these wastes over conventional methods. This paper explores examples of some of these techniques employed on cement kiln dust (CKD) and pulp and paper mill process waste. Similar to Portland Cement, unleached CKD contains free lime and sources of reactive

Christopher S. Peters

1998-01-01

44

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 ...

45

Improved control of the finish grinding process in cement manufacture  

SciTech Connect

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.

Menacho, J.M.; Austin, L.G.; Cuhadaroglu, M.S. (Pennsylvania State Univ., University Park, PA (USA). Dept. of Mineral Processing)

1985-01-01

46

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

USGS Publications Warehouse

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 bot

Mossotti, Victor G.

2014-01-01

47

Functionally-graded fiber-reinforced cement composite: Processing, microstructure, and properties  

E-print Network

Functionally-graded fiber-reinforced cement composite: Processing, microstructure, and properties-graded fiber-reinforced cement composite (FGFRCC). Fiber volume fractions were increased linearly from 0. Flexural tests were carried out to characterize the mechanical behavior and to evaluate the effectiveness

Paulino, Glaucio H.

48

DHP algorithm based multi-variable optimal control for cement calcination process  

Microsoft Academic Search

Cement precalciner kiln(PCK) clinker calcination process is a matter of mass transfer, heat transfer, physical and chemical reactions, and more complex multi-variable nonlinear system with more disturbances. In order to reduce energy consumption and to ensure the quality of cement clinker burning, one needs to explore different control methods from the traditional way. In this paper, PCK technology is conducted

Baosheng Yang; Xiushui Ma

2010-01-01

49

Electrical conductivity is a parameter that can be used to monitor the entire hardening process of oilwell cement slurries. The theo-  

E-print Network

process of oilwell cement slurries. The theo- retical relationship among conductivity, porosity, cement and that rapid hydration will reduce the risk of gas migration. Introduction The main purposes of oilwell cements hardening process of oilwell cement slurries is important for successful cementing operations. Several

Backe, Knut

50

Asbestos fibre release by corroded and weathered asbestos-cement products.  

PubMed

A description is given of portable equipment and a method of sampling and measuring asbestos fibre emissions from solid plane surfaces of asbestos-cement products (roofs and facades). Asbestos-cement products, e.g., roof tiles, contain as much as 11-12% of chrysotile asbestos. As a result of continuing exposure to the weather and to acid rain, the surface of asbestos-cement products becomes corroded and weathered. Cement particles, asbestos fibres and agglomerates of particles and fibres are therefore released from the surface and dispersed in air and water. The method described has been used to measure asbestos fibre emissions and ambient air concentrations in the Federal Republic of Germany over the period 1984-1986. PMID:2744837

Spurny, K R

1989-01-01

51

Utilization of separator bag filter dust for high early strength cement production  

Microsoft Academic Search

This paper presents the feasibility of incorporating ultra-fine particles collected in the separator bag filter during the process of manufacturing cement (SBFC) as an substitution material for cement. Approximately 2.5% of SBFC is produced during OPC manufacturing process. Also, the average size of SBFC particles is about 5?m, the average size of OPC particles is about 14?m. This method does

Kwang Ho Sho; Sang Joon Park; Yong Jic Kim; Gun Cheol Lee; Kyoung Min Kim

2011-01-01

52

The use of Devonian oil shales in the production of portland cement  

SciTech Connect

The Lafarge Corporation operates a cement plant at Alpena, Michigan in which Antrim shale, a Devonian oil shale, is used as part of the raw material mix. Using this precedent the authors examine the conditions and extent to which spent shale might be utilized in cement production. They conclude that the potential is limited in size and location but could provide substantial benefit to an oil shale operation meeting these criteria.

Schultz, C.W.; Lamont, W.E. (Alabama Univ., University, AL (United States)); Daniel, J. (Lafarge Corp., Alpena, MI (United States))

1991-01-01

53

The use of Devonian oil shales in the production of portland cement  

SciTech Connect

The Lafarge Corporation operates a cement plant at Alpena, Michigan in which Antrim shale, a Devonian oil shale, is used as part of the raw material mix. Using this precedent the authors examine the conditions and extent to which spent shale might be utilized in cement production. They conclude that the potential is limited in size and location but could provide substantial benefit to an oil shale operation meeting these criteria.

Schultz, C.W.; Lamont, W.E. [Alabama Univ., University, AL (United States); Daniel, J. [Lafarge Corp., Alpena, MI (United States)

1991-12-31

54

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

PubMed

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

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

2009-06-15

55

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

SciTech Connect

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.

Maimoni, A.

1982-01-01

56

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

NASA Astrophysics Data System (ADS)

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 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

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

57

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...

58

Cement and concrete  

NASA Technical Reports Server (NTRS)

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.

Corley, Gene; Haskin, Larry A.

1992-01-01

59

Sculpting with Cement.  

ERIC Educational Resources Information Center

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)

Olson, Lynn

1983-01-01

60

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

Microsoft Academic Search

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)

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

2009-01-01

61

Dolomite magnesium oxychloride cement properties control method during its production  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

62

Alex Benson Cement Plants  

E-print Network

Alex Benson ATOC 3500 Cement Plants 4 Step Production Line: o Mine the Limestone: Cement plants usually located near quarries to lower transportation costs. o Cement Kiln: Limestone is mixed with sand with steel balls which grind mix into a fine powder -> Final Cement Product Associated Air Pollution: o From

Toohey, Darin W.

63

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

NASA Astrophysics Data System (ADS)

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 = 20-1200°C 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.

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

2014-06-01

64

Biphasic products of dicalcium phosphate-rich cement with injectability and nondispersibility.  

PubMed

In this study, a calcium phosphate cement was developed using tetracalcium phosphate and surface-modified dicalcium phosphate anhydrous (DCPA). This developed injectable bone graft substitute can be molded to the shape of the bone cavity and set in situ through the piping system that has an adequate mechanical strength, non-dispersibility, and biocompatibility. The materials were based on the modified DCPA compositions of calcium phosphate cement (CPC), where the phase ratio of the surface-modified DCPA is higher than that of the conventional CPC for forming dicalcium phosphate (DCP)-rich cement. The composition and morphology of several calcium phosphate cement specimens during setting were analyzed via X-ray diffractometry and transmission electron microscopy coupled with an energy dispersive spectroscopy system. The compressive strength of DCP-rich CPCs was greater than 30MPa after 24h of immersion in vitro. The reaction of the CPCs produced steady final biphasic products of DCPs with apatite. The composites of calcium phosphate cements derived from tetracalcium phosphate mixed with surface-modified DCPA exhibited excellent mechanical properties, injectability, and interlocking forces between particles, and they also featured nondispersive behavior when immersed in a physiological solution. PMID:24863195

Ko, Chia-Ling; Chen, Jian-Chih; Hung, Chun-Cheng; Wang, Jen-Chyan; Tien, Yin-Chun; Chen, Wen-Cheng

2014-06-01

65

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

SciTech Connect

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.

Park, S.B. [Chungnam National Univ., Taejon (Korea, Republic of). Dept. of Civil Engineering] [Chungnam National Univ., Taejon (Korea, Republic of). Dept. of Civil Engineering; Yoon, E.S. [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of). Dept. of Structural Systems and Site Evaluation] [Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of). Dept. of Structural Systems and Site Evaluation; Lee, B.I. [Clemson Univ., SC (United States). Dept. of Ceramic and Materials Engineering] [Clemson Univ., SC (United States). Dept. of Ceramic and Materials Engineering

1999-02-01

66

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...

67

A study on the process for formation of spherical cement through an examination of the changes of powder properties and electrical charges of the cement and its constituent materials during surface modification  

Microsoft Academic Search

In the initial stage of surface modification treatment to form cement particles into a spherical shape, the fine cement particles below 3 ?m increased and the specific surface area also increased. However, in the final stage of treatment, both the fine particles and the specific surface area decreased when compared to raw cement. These results seem to endorse a process

Isao Tanaka; Masumi Koishi; Kunio Shinohara

2002-01-01

68

Silicon production process evaluations  

NASA Technical Reports Server (NTRS)

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.

1982-01-01

69

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)...

70

Elman neural network based temperature prediction in cement rotary kiln calcining process  

Microsoft Academic Search

Cement rotary kiln calcining process is a kind of functional equipment for fuel combustion, heat exchange, and chemical reaction. A complex succession of chemical reactions takes place as the temperature rises. One can not establish a precise mathematical model of rotary kiln, so it is difficult to achieve its optimal control. In order to accurately reflect the system dynamic characteristics,

Baosheng Yang; Xiushui Ma; Qian Zhang

2010-01-01

71

INDUSTRIAL PROCESS PROFILES FOR ENVIRONMENTAL USE: CHAPTER 21. THE CEMENT INDUSTRY  

EPA Science Inventory

The catalog of Industrial Process Profiles for Environmental Use was developed as an aid in defining the environmental impacts of industrial activity in the United States. Entries for each industry are in consistent format and form separate chapters of the study. The cement indus...

72

Reuse of de-inking sludge from wastepaper recycling in cement mortar products.  

PubMed

This paper presents results of an investigation into the use of de-inking sludge from a paper recycling mill as feedstock material in the manufacture of cement mortar products, including masonry blocks and mortar renders. Both physical and mechanical properties of mortar specimens containing various amounts of de-inking sludge were investigated. It was observed that the addition of de-inking sludge to cement mortar at a fixed water-to-cement ratio significantly reduced flow properties and increased setting time. Water absorption and volume of permeable voids of cement mortar increased with increased dosage of de-inking sludge, with a corresponding reduction of bulk density. The 91-day compressive strength of mortar samples with 2.5 wt% and 20 wt% de-inking sludge loadings retained 83% and 62% respectively of the reference mortar strength. The corresponding drying shrinkage increased by up to 160% compared to reference samples. However, a de-inking sludge loading of up to 2.5 wt% did not significantly alter measured physical and mechanical properties. The results demonstrate that despite the high moisture absorbance of de-inking sludge due to its organic matter and residual cellulose fibre content, it serves as a potential supplementary additive and its cellulosic content proving to be an active set retardant to cementitious masonry products. PMID:21507557

Yan, Shiqin; Sagoe-Crentsil, Kwesi; Shapiro, Gretta

2011-08-01

73

Sustainability of the cement and concrete industries UWM Center for By-Products Utilization, University of Wisconsin-Milwaukee, Milwaukee, WI, USA  

E-print Network

Sustainability of the cement and concrete industries T.R. Naik UWM Center for By of the most widely used construction materials in the world. However, the production of portland cement); production of one ton of portland cement produces about one ton of CO2 and other GHGs. The environmental

Wisconsin-Milwaukee, University of

74

EVOLUCIÓN MINERALÓGICA DEL CEMENTO PORTLAND DURANTE EL PROCESO DE HIDRATACIÓN MINERALOGICAL EVOLUTION OF PORTLAND CEMENT DURING HYDRATION PROCESS  

Microsoft Academic Search

An investigation about mineralogical evolution during hydration process of the portland cement was carried out in this work using techniques of materials characterization, such as X ray diffraction (XRD) and scanning electron microscopy (SEM) in order to understand the behaviour shown by the different minerals of the cement (alite, belite, celite and felite) and their transformation in the stables hydrate

JORGE IVÁN TOBÓN

75

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

PubMed Central

To evaluate the effects of thermocycling (500 cycles, 5°C/55°C) 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

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

2013-01-01

76

Investigative and management techniques for cement kiln dust and pulp and paper process wastes  

SciTech Connect

Knowledge of the characteristics of industrial process wastes allows for some innovative and cost savings techniques for investigating and managing these wastes over conventional methods. This paper explores examples of some of these techniques employed on cement kiln dust (CKD) and pulp and paper mill process waste. Similar to Portland Cement, unleached CKD contains free lime and sources of reactive silica and/or alumina. Thus, it can set up in the presence of water. Properly moisture-conditioned CKD has been successfully used in Michigan as a landfill liner and cover material on closures of old CKD piles and newly permitted fills. However, CKD also contains high concentrations of soluble salts and when improperly managed can generate a leachate with high total dissolved solid concentrations. Surface and downhole geophysical methods employing electromagnetic conductivity have proven effective in delineating the horizontal and vertical extent of groundwater plumes caused by releases of CKD leachate.

Peters, C.S. [RMT, Inc., Okemos, MI (United States)

1998-12-31

77

CEMENT MANUFACTURING USING ALTERNATIVE FUELS AND THE ADVANTAGES OF PROCESS MODELLING  

Microsoft Academic Search

Energy costs and environmental standards encouraged cement manufacturers world-wide to evaluate to what extent conventional fuels can be replaced by alternative fuels, i.e. processed waste materials. Clinker burning is well suited for various alternative fuels. In order select a suitable alternative fuel a commercial modelling tool (ASPEN PLUS®) is used to model the four- stage pre-heater kiln system of a

Ursula Kääntee; Ron Zevenhoven; Rainer Backman; Mikko Hupa

2004-01-01

78

Sintering status recognition system for cement rotary kiln  

Microsoft Academic Search

Because of complex status of the burning zone, cement rotary kiln production control depends on man-watch operation mode, which causes problems of weak coherence of product quality and big depletion of resources. Put forward a computer-recognition system for Sintering status recognition by image processing and pattern recognition techniques, then design and develop a recognition system for cement rotary kiln process

Jinxin Liu; Yunlong Zhu; Peng Sun

2010-01-01

79

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

SciTech Connect

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.

Dimotakis, E.D.; Klemperer, W.G.; Young, J.F. [Univ. of Illinois, Urbana, IL (United States)

1993-12-31

80

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

SciTech Connect

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.

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

2012-02-10

81

Support vector machine model based predictive pid control system for cement rotary kiln  

Microsoft Academic Search

The rotary kiln calcination is the most important part of cement production including complicated physical and chemical reaction processes with large inertia, pure hysteresis, nonlinearity and strong coupling characteristics. Considering the need of advanced process control in cement industry, this paper presents the application of support vector machine modeling and generalized predictive control PID control algorithm to the conventional cement

Zheng Li

2010-01-01

82

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

PubMed

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

Viani, Alberto; Gualtieri, Alessandro F

2013-09-15

83

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

SciTech Connect

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.

Generosi, A. [Istituto di Struttura della Materia, CNR, via del Fosso del Cavaliere, 100-00133 Rome (Italy); Smirnov, V.V. [Institute for Physical Chemistry of Ceramics, Russian Academy of Sciences, Ozernaya 48, Moscow 119361 (Russian Federation); Rau, J.V. [Istituto per lo Studio dei Materiali Nanostrutturati, CNR, Piazzale Aldo Moro, 5-00185 Rome (Italy); Albertini, V. Rossi [Istituto di Struttura della Materia, CNR, via del Fosso del Cavaliere, 100-00133 Rome (Italy); Ferro, D. [Istituto per lo Studio dei Materiali Nanostrutturati, CNR, Piazzale Aldo Moro, 5-00185 Rome (Italy); Barinov, S.M. [Institute for Physical Chemistry of Ceramics, Russian Academy of Sciences, Ozernaya 48, Moscow 119361 (Russian Federation)], E-mail: barinov_s@mail.ru

2008-03-04

84

Improved processing for oil well cement evaluation-a with theoretical and laboratory data.  

PubMed

A processing technique to measure cement impedance from ultrasonic pulse-echo waveforms, called normalized single mode (NSM) processing, is described. The technique is based on a physical model that represents the transducer in terms of its continuous plane wave kernel. Narrowband filtering to process a single resonant mode and all processing parameters are normalized to the modal frequency. The performance of NSM and a digital simulation of the present analog commercial processing, W2/W1, is compared for several environmental effects: casing thickness, eccentering, and added Gaussian noise. The computation is based on waveforms from a mathematical model and laboratory data. Results on model data show that NSM processing significantly reduces the impedance errors due to thickness variations, eccentering, and noise. Results on laboratory data indicate that the techniques yield comparable results for smooth machined casings, but that NSM processing significantly reduces measurement error and variance in a sample of the actual oil field casing. PMID:18263130

Kimball, C V

1992-01-01

85

Production of cytokines around loosened cemented acetabular components. Analysis with immunohistochemical techniques and in situ hybridization.  

PubMed

The chronic inflammatory response to wear particles from orthopaedic joint implants is believed to cause osteolysis and to contribute to prosthetic loosening. Previous in vitro experiments have demonstrated that particulate debris from joint implants causes cells in culture to release products that have been implicated in this pathological bone resorption. The purpose of the current study was to investigate the in vivo features of this complex process in patients who had had a total hip replacement. Membraneous tissue was obtained from the cement-bone interface of ten polyethylene acetabular components that had been revised for aseptic loosening in ten patients. The immunoperoxidase technique, which involves the use of specific antibodies for each cell type, showed that macrophages were the predominant cellular constituents but also that fibroblasts, many of which were not identified on plain histological study, were present and were actively producing collagen. T lymphocytes were present variably, but they generally composed less than 10 percent of the cells. Particulate debris (polyethylene, methylmethacrylate, and metal) was present in all membrane specimens but was intracellular only in macrophages and multinucleated giant cells. 35S-labeled nucleic-acid probes, complementary to human interleukin-1-beta and to platelet-derived growth-factor-2 messenger RNA (mRNA), were hybridized with serial tissue sections. Hybridization demonstrated interleukin-1-beta mRNA predominantly in macrophages, and not in fibroblasts or in T lymphocytes to any major extent. In contrast, immunolocalization demonstrated interleukin-1-beta protein on both macrophages and fibroblasts, suggesting that macrophages release interleukin-1-beta, which then binds to both fibroblasts and macrophages. Platelet-derived growth-factor transcripts were found in both macrophages and fibroblasts. PMID:8314826

Jiranek, W A; Machado, M; Jasty, M; Jevsevar, D; Wolfe, H J; Goldring, S R; Goldberg, M J; Harris, W H

1993-06-01

86

Sponsors of CIEEDAC: Natural Resources Canada, Canadian Industry Program for Energy Conservation, Aluminium Industry Association, Canadian Petroleum Products Institute, Canadian Portland Cement Association, Canadian Pulp  

E-print Network

, Aluminium Industry Association, Canadian Petroleum Products Institute, Canadian Portland Cement Association increases, alternative collection of industry specific data may be carried out through ICE, considered

87

Recent developments in the lime-fly ash process for alumina and cement  

SciTech Connect

Recent developments from research of the limestone-fly ash sinter process for the extraction of alumina from coal fly ash and use of the residue in the manufacture of portland cement may result in substantial reductions in processing costs. It has been found that cement kiln dust can be used in place of limestone, and that the addition of coal refuse to the sinter mixture will increase alumina recovery and reduce kiln temperatures required. The soluble compound formed in the sintering reactions has been identified through use of XRD methods. Compound formation conditions have been determined for a range of sinter compositions. A systematic investigation of minor additives to sinter compositions has resulted in the determination of a group of ions which, when present in sintered material, will prevent the auto-disintegration (dusting) of the clinker formed. Several ions, even at very low concentrations, can enter the lattice of the major sinter compound, calcium orthosilicate (C/sub 2/S) and inhibit the phase transformation of ..beta..-C/sub 2/S to ..gamma..-C/sub 2/S and the accompanying lattice expansion that causes clinker disintegration. The understanding gained about clinker disintegration, conditions for formation of specific soluble compounds in the clinker, and the roles of coal refuse-derived iron and sulfur in sinter reactions can lead to improvements in the sinter process and enhanced profitability. Use in the process of other wastes provides further incentive for coal ash processing to meet our nation's requirements for alumina and cement, and provide an alternative form of coal combustion waste disposal.

Murtha, M.J.; Burnet, G.

1981-01-01

88

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

SciTech Connect

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.

DAYLEY, L.

2000-06-14

89

Identification of cement rotary kiln using hierarchical wavelet fuzzy inference system  

Microsoft Academic Search

Rotary kiln is the central and the most complex component of cement production process. It is used to convert calcineous raw meal into cement clinkers, which plays a key role in quality and quantity of the final produced cement. This system has complex nonlinear dynamic equations that have not been completely worked out yet. In conventional modeling procedure, a large

A. Sharifi; M. Aliyari Shoorehdeli; M. Teshnehlab

90

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

Microsoft Academic Search

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,

S. J. Weiss; S. W. Tresouthick

1987-01-01

91

Properties and hydration products of lightweight and expansive cements. Part I: Physical and mechanical properties  

SciTech Connect

Results from studies on the physical and mechanical properties of lightweight and expansive cements cured at 20 and 75 C are presented. Lightweight additive (cenospheres from thermoelectric power station Bobov Dol, Bulgaria) and expansive additive (Bulexa with hydroxide type of expansion) were used. The compressive and flexural strength, the gas and water impermeability, and the pore structure of the cement stone of lightweight and expansive cements were investigated. The results are compared with corresponding parameters of cement stone without additives. It was found that the cenospheres are appropriate lightweight additives. The use of expansive additive helps overcome the dry shrinkage of cement stone and strengthens the bond with the bounding surfaces.

Lilkov, V.; Djabarov, N.; Bechev, G.; Kolev, K.

1999-10-01

92

SEM/EDX characterization of the hydration products of belite cements from class C coal fly ash  

SciTech Connect

This paper presents the microscopic characterization of two types of fly ash belite cements and their hydration products by means of scanning electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction analysis. The cements were obtained from ASTM class C coal fly ash by the hydrothermal-calcination route in water (FABC-2-W) and NaOH 1M solution (FABC-2-N). The hydration was studied during a period of 180 days at 21{sup o}C and >95% RH. The results showed significant incorporation of aluminum (Al) into the C-S-H gel and other minor elements, with a presumable composition close to that of aluminum-tobermorite. The C-S-H composition of the FABC-2-W is more stable over the hydration time than that of the FABC-2-N cement. Portlandite is scarcely formed during hydration.

Goni, S.; Guerrero, A. [CSIC, Madrid (Spain)

2007-12-15

93

Model predictive control of a rotary cement kiln  

Microsoft Academic Search

A first principles model of a cement kiln is used to control and optimize the burning of clinker in the cement production process. The model considers heat transfer between a gas and a feed state via convection and radiation. Furthermore, it contains effects such as chemical reactions, feed transport, energy losses and energy input. A model predictive controller is used

Konrad S. Stadler; Jan Poland; Eduardo Gallestey

2011-01-01

94

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

NASA Astrophysics Data System (ADS)

A colluvial origin is postulated for the enigmatic relic mantle of immature, carbonate-cemented rudites on the bedrock slope of Kraków 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 Kraków Highland was probably extensive, but was removed by subsequent erosion where non-cemented.

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

2014-06-01

95

Acrylamide in processed potato products  

Technology Transfer Automated Retrieval System (TEKTRAN)

Trace amounts of acrylamide are found in many foods cooked at high temperatures. Acrylamide in processed potato products is formed from reducing sugars and asparagine and is a product of the Maillard reaction. Processed potato products including fries and chips are relatively high in acrylamide comp...

96

Investigative and management techniques for cement kiln dust and pulp and paper mill process wastes  

SciTech Connect

Knowledge of the characteristics of industrial process wastes allows for some innovative and cost savings techniques for investigating and managing these wastes over conventional methods. This paper explores examples of some of these techniques employed on cement kiln dust (CKD) and pulp and paper mill process waste. Similar to Portland Cement, unleached CKD contains free lime and sources of reactive silica and/or alumina. Thus, it can set up in the presence of water. Properly moisture conditioned CKD has been successfully used in Michigan as a landfill liner and cover material on closures of old CKD piles and newly permitted fills. In addition to its pozzolanic properties, CKD contains high concentrations of soluble salts, generating a leachate with high total dissolved solids concentrations. Surface and downhole geophysical methods employing electromagnetic conductivity have proven effective in delineating the horizontal and vertical extent of groundwater plumes. At one paper mill in Alabama where dewatered filter cake had been placed in a lined solid waste facility, liquids that had migrated to the surface due to excessive gas pressures caused unstable working conditions at the surface. Large, vertical french drains and a horizontal drainage blanket consisting of geogrid and sand constructed over the existing waste resulted in dewatering and a substantial increase in waste stability, allowing a vertical expansion to proceed. At a kraft mill in the southeastern US, a geotechnical investigation of a lime mud pond revealed that the stability of the unit would increase by construction of an overlying dike, thereby allowing a vertical expansion to proceed. Finally, laboratory testing and modeling of the behavior of paper mill sludges indicates that they can be used as a landfill cover with permeabilities equivalent to or better than compacted clay.

Peters, C.S. [RMT, Inc., Okemos, MI (United States)

1997-12-31

97

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...

98

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...

99

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...

100

Identification, Prediction and Detection of the Process Fault in a Cement Rotary Kiln by Locally Linear Neuro-Fuzzy Technique  

Microsoft Academic Search

In this paper, we use nonlinear system identification method to predict and detect process fault of a cement rotary kiln. After selecting proper inputs and output, an input-output model is identified for the plant. To identify the various operation points in the kiln, Locally Linear Neuro-Fuzzy (LLNF) model is used. This model is trained by LOLIMOT algorithm which is an

Masoud Sadeghian; Alireza Fatehi

2009-01-01

101

Product Automata and Process Algebra  

Microsoft Academic Search

We dene a model of labelled product systems of automata and explore its connections with process calculi and trace languages. Bisimilarity of labelled product systems is de- ned using a new denition of bisimulation with renam- ing. Concurrent \\

Kamal Lodaya

2006-01-01

102

Biorefineries – Multi Product Processes  

Microsoft Academic Search

The development of biorefineries represents the key for access to an integrated production of food, feed, chemicals, materials, goods, and fuels of the future?[1]. Biorefineries combine the necessary technologies of the biogenic raw materials with those of intermediates and final products. The main focus is directed at the precursors carbohydrates, lignin, oils, and proteins and the combination between biotechnological and

B. Kamm; M. Kamm

103

Optimization of copper cementation process by iron using central composite design experiments  

Microsoft Academic Search

In this study, the effects of various experimental parameters on the cementation yield of copper by iron were investigated statistically. A statistical experimental design based on the second-order central composite rotatable design (CCRD) was planned fixing the cementation period at 2h. The experimental design was done at five levels of the operating parameters which were the initial copper concentration, temperature,

W. Djoudi; F. Aissani-Benissad; S. Bourouina-Bacha

2007-01-01

104

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

PubMed

This investigation focuses on the reuse of grits waste as a raw material for replacing Portland cement by up to 30 wt.% 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

Siqueira, F B; Holanda, J N F

2013-12-15

105

Silicon production process evaluations  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

106

Cement grinding optimisation  

Microsoft Academic Search

The current world consumption of cement is about 1.5 billion tonnes per annum and it is increasing at about 1% per annum. The electrical energy consumed in cement production is approximately 110kWh\\/tonne, and around 40% of this energy is consumed for clinker grinding. There is potential to optimise conventional cement clinker grinding circuits and in the last decade significant progress

Alex Jankovic; Walter Valery; Eugene Davis

2004-01-01

107

NASA Product Peer Review Process  

NASA Technical Reports Server (NTRS)

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.

Jenks, Ken

2009-01-01

108

Neuro-controller of cement rotary kiln temperature with adaptive critic designs  

Microsoft Academic Search

The production process of the cement rotary kiln is a typical engineering thermodynamics with large inertia, lagging and nonlinearity. So it is very difficult to control this process accurately using traditional control theory. In order to guarantee the process to be stable, and to produce the high-grade cement clinker, it is important to make the temperature of the sintering zone

Xiaofeng Lin; Tangbo Liu; Shaojian Song; Chunning Song

2009-01-01

109

Soft sensor for real-time cement fineness estimation.  

PubMed

This paper describes the design and implementation of soft sensors to estimate cement fineness. Soft sensors are mathematical models that use available data to provide real-time information on process variables when the information, for whatever reason, is not available by direct measurement. In this application, soft sensors are used to provide information on process variable normally provided by off-line laboratory tests performed at large time intervals. Cement fineness is one of the crucial parameters that define the quality of produced cement. Providing real-time information on cement fineness using soft sensors can overcome limitations and problems that originate from a lack of information between two laboratory tests. The model inputs were selected from candidate process variables using an information theoretic approach. Models based on multi-layer perceptrons were developed, and their ability to estimate cement fineness of laboratory samples was analyzed. Models that had the best performance, and capacity to adopt changes in the cement grinding circuit were selected to implement soft sensors. Soft sensors were tested using data from a continuous cement production to demonstrate their use in real-time fineness estimation. Their performance was highly satisfactory, and the sensors proved to be capable of providing valuable information on cement grinding circuit performance. After successful off-line tests, soft sensors were implemented and installed in the control room of a cement factory. Results on the site confirm results obtained by tests conducted during soft sensor development. PMID:25451819

Staniši?, Darko; Jorgovanovi?, Nikola; Popov, Nikola; Congradac, Velimir

2014-10-23

110

Hafnium powder production processes  

NASA Astrophysics Data System (ADS)

The conditions for the production of hafnium nanopowders via magnesium-thermic reduction of chlorides and the effect of these conditions on the phase composition and dispersion of the powders are studied analytical chemistry, X-ray diffractin, and electron microscopy. The results of phase and structural analysis of the powders, the results of microscopic studies, the measured specific surface, and the data of atomicemission analysis are presented.

Dzidziguri, E. L.; Salangina, E. A.; Sidorova, E. N.

2010-09-01

111

Lunar cement  

NASA Technical Reports Server (NTRS)

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.

Agosto, William N.

1992-01-01

112

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

SciTech Connect

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.

Lu, Hongyou; Masanet, Eric; Price, Lynn

2009-05-29

113

Performance Cements Focus on Sustainability  

E-print Network

. Production and quality control of limestone cements Limestone grinds more easily than clinker OverallPerformance Cements Focus on Sustainability Tim Cost, P.E. Senior Technical Service Engineer tim.cost@holcim.com NCC Meeting Baton Rouge April 9, 2008 #12;2 High Limestone Cements 5/21/08 Cost Holcim (US) Inc

114

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

SciTech Connect

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.

Cruz, J.M. [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain)] [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Fita, I.C., E-mail: infifer@fis.upv.es [Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera, 46022, Valencia (Spain); Soriano, L.; Payá, J.; Borrachero, M.V. [ICITECH, Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València (Spain)] [ICITECH, Instituto de Ciencia y Tecnología del Hormigón, Universitat Politècnica de València (Spain)

2013-08-15

115

Products and Processes: Synergistic Relationships  

ERIC Educational Resources Information Center

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.…

Wallace, Virginia; Husid, Whitney

2013-01-01

116

Control system design of cement rotary kiln based on PID neuron networks  

Microsoft Academic Search

In the process of cement production, the rotary kiln calcination is the most important technology link which includes complicated physical and chemical reaction process with large inertia, pure hysteresis, nonlinearity and strong coupling characteristics. It is hard to derive the exact mathematical model and can not reach satisfied results with conventional control algorithms. Now, the cement rotary kilns are mainly

Zengtao Xue; Zheng Li

2009-01-01

117

Design of fuzzy neural network based control system for cement rotary kiln  

Microsoft Academic Search

This paper presents a fuzzy neural network control system for the process of cement production with rotary cement kiln. Since the dynamic characteristics and reaction process parameters are with large inertia, pure hysteresis, nonlinearity and strong coupling, a fuzzy neural network controller combining both the advantages of neural network and fuzzy control is applied. This fuzzy neural network controller adjusts

Zheng Li

2010-01-01

118

High temperature lightweight foamed cements  

DOEpatents

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.

Sugama, Toshifumi.

1989-10-03

119

Reducing cement's CO2 footprint  

USGS Publications Warehouse

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.

van Oss, Hendrik G.

2011-01-01

120

High temperature lightweight foamed cements  

DOEpatents

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.

Sugama, Toshifumi (Mastic Beach, NY)

1989-01-01

121

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

SciTech Connect

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.

Robert Weber; Norman Whitton

2010-09-30

122

Designing of Cement-Based Formula for Solidification\\/Stabilization of Hazardous, Radioactive, and Mixed Wastes  

Microsoft Academic Search

Solidification\\/stabilization (S\\/S) is often used to treat waste or to remediate contaminated sites. Many people feel S\\/S is just a process to consolidate waste into a solid product for disposal using cementing materials. This article describes designing a cement-based formula for solidification\\/stabilization of wastes or contaminated soils from aspects of both the cement chemistry and the environmental chemistry. The discussion

CAIJUN SHI; ROGER SPENCE

2004-01-01

123

Asphalt cement  

MedlinePLUS

... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. This is ... Road paving materials Roofing materials Tile cements Note: This list may not include all uses of asphalt.

124

Bone cement  

PubMed Central

The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc.

Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

2013-01-01

125

Discovery Reconceived: Product before Process  

ERIC Educational Resources Information Center

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…

Abrahamson, Dor

2012-01-01

126

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

SciTech Connect

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.

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

2010-12-22

127

Modern production process for magnesium  

SciTech Connect

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.

Wilson, C.B. [Dow Chemical Co., Freeport, TX (United States)

1996-10-01

128

Change in pore structure and composition of hardened cement paste during the process of dissolution  

SciTech Connect

An understanding about the dissolution phenomena of cement hydrates is important to assess changes in the long-term performance of radioactive waste disposal facilities. To investigate the alteration associated with dissolution, dissolution tests of ordinary Portland cement (OPC) hydrates were performed. Through observation of the samples after leaching, it was confirmed that ettringite precipitation increased as the dissolution of the portlandite and the C-S-H gel progressed. EPMA performed on cross-sections of the solid phase showed a clear difference between the altered and unaltered parts. The boundary between the two parts was termed the portlandite (CH) dissolution front. As the leaching period became longer, the CH dissolution front shifted toward the inner part of the sample. A linear relationship was derived by plotting the distance moved by the CH dissolution front against the square root of the leaching time. This indicated Ca ion movement by diffusion.

Haga, Kazuko; Shibata, Masahito; Hironaga, Michihiko; Tanaka, Satoru; Nagasaki, Shinya

2005-05-01

129

Neutron diffraction for studying the influence of the relative humidity on the carbonation process of cement pastes  

NASA Astrophysics Data System (ADS)

The effect of humidity on hydrated cement carbonation has been studied by means of in-situ neutron diffraction measurements. The evolution of the main crystalline phases in the bulk of the sample, portlandite and calcite, has been monitored during the process. Data obtained from neutron diffraction allow the quantification of the phases involved. The results highlight the great influence of humidity on carbonation. At very low humidity there are almost no changes. Between 53 and 75% relative humidity, portlandite decrease and calcite increase data can be fitted to exponential decay functions. At very high humidity portlandite remains nearly constant while calcite increases slightly with time, almost linearly.

Galan, I.; Andrade, C.; Castellote, M.; Rebolledo, N.; Sanchez, J.; Toro, L.; Puente, I.; Campo, J.; Fabelo, O.

2011-10-01

130

Performance of Concrete Made With Slag Cement and  

E-print Network

Performance of Concrete Made With Slag Cement and Portland-Limestone Blended Cement Philadelphia;Today's Discussion ! The materials ! Slag cement ! Portland-limestone cement ! Use in concrete is slag cement? #12;! Non-metallic product of an iron blast furnace ! Granulated ! Ground ! Cementitious

131

C emQUANT ® software Mathematical modeling in quantitative phase analysis of Portland cement  

Microsoft Academic Search

It is necessary to determine a complete mineralogy of clinker cement to correctly understand, interpret, and predict the outcome of any plant production process. The cement industry's standard method (ASTM C 150) used in quantitative phase analysis of alite, belite, aluminate, and ferrite has long been known to provide approximate concentrations. The wet chemical and optical microscopy methods are too

B. Feret; C. F. Feret

1999-01-01

132

Synthesis: Intertwining product and process  

NASA Technical Reports Server (NTRS)

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.

Weiss, David M.

1990-01-01

133

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

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

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

2013-01-01

134

Comparison of intergrinding and separate grinding for the production of natural pozzolan and GBFS-incorporated blended cements  

Microsoft Academic Search

A portland cement clinker, a natural pozzolan, and a granulated blast furnace slag (GBFS) were used to obtain blended cements that contain 25% mineral additives. The natural pozzolan, which was softer, was more grindable and granulated blast furnace slag, which was harder, was less grindable than the clinker. Two of the cements produced were obtained by intergrinding and the other

K Erdogdu; M Tokyay; P Türker

1999-01-01

135

Reuse of fresh water sludge in cement making.  

PubMed

With the increasing demand for high quality water, a large quantity of chemical agent must be added in the water purification process, which in turn generates enormous amount of fresh water sludge. Of all the options for sludge disposal, sludge reuse has been considered most economical and environmentally sound. This study evaluated the possibility of incorporating fresh water sludge in the making of Portland cement through the sintering process. The goal was to search for the optimal condition to maximize the replacement of clay with the fresh water sludge. Characteristics of fresh water sludge were collected and analyzed. The analysis showed that water source and water treatment process dominate th characteristics, particularly the chemical composition of the fresh water sludge. The fresh water sludge was mixed with the cement clay in various percentages, from 0% to 100%, as raw material for cement-making. The effects of its addition on the sintering condition and the quality of cement were evaluated. The analysis of the clinkers showed that the addition of the fresh water sludge did not change the phase form and the f-CaO content of the cement. The compressive strength of the masonry increased with the increasing addition of fresh water sludge. All cement products made from various replacement ratios met the Chinese National Standard of first degree Portland cement. PMID:15581011

Pan, R; Huang, C; Lin, S

2004-01-01

136

The FGM Concept in the Development of Fiber Cement Components  

SciTech Connect

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.

Dias, C. M. R.; John, V. M. [Department of Construction Engineering, Polytechnic School, University of Sao Paulo, 05508 900 Sao Paulo, SP (Brazil); Savastano, H. Jr. [Faculty of Animal Science and Food Engineering, University of Sao Paulo, Av. Duque de Caxias Norte 225, P.O. Box 23, 13635-900 Pirassununga, SP (Brazil)

2008-02-15

137

Thermodynamics and cement science  

SciTech Connect

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.

Damidot, D., E-mail: damidot@ensm-douai.fr [Universite Lille Nord de France (France); EM Douai, LGCgE-MPE-GCE, Douai (France); Lothenbach, B. [Empa, Lab. Concrete and Construction Chemistry, Duebendorf (Switzerland); Herfort, D. [Cementir Holding (Denmark); Glasser, F.P. [Chemistry Department, University of Aberdeen, Aberdeen (United Kingdom)

2011-07-15

138

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

SciTech Connect

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.

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

1998-12-31

139

Research of magnesium phosphosilicate cement  

NASA Astrophysics Data System (ADS)

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.)

Ding, Zhu

140

Fundamental study of clay-cement kiln dust (CKD) interaction to determine the effectiveness of CKD as a potential clay soil stabilizer  

Microsoft Academic Search

Cement kiln dusts (CKDs) are by-products of the cement manufacturing process that are removed from the stream of kiln gases as they pass through the kiln’s dust collection system during clinker production. The feasibility of using cement kiln dusts (CKDs) as potential stabilizing agents for kaolinite, Na-montmorillonite and Ca-montmorillonite clay was investigated in this research. A suite of four CKDs

Sulapha Peethamparan

2006-01-01

141

Chemical production processes and systems  

SciTech Connect

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.

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

2014-06-17

142

Thermal Shock-resistant Cement  

SciTech Connect

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.

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

2012-02-01

143

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

SciTech Connect

The simultaneous chromizing-aluminizing of low-alloy steels has achieved Kanthal-like surface compositions of 16--2lCr and 5--8 wt%Al 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 core of the austenitic substrate, thereby preventing 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 in air were observed over a wide range of relatively low temperatures (637--923{degrees}C).

Geib, F.D.; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering

1992-11-01

144

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

SciTech Connect

The simultaneous chromizing-aluminizing of low-alloy steels has achieved Kanthal-like surface compositions of 16--2lCr and 5--8 wt%Al 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 core of the austenitic substrate, thereby preventing 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 in air were observed over a wide range of relatively low temperatures (637--923[degrees]C).

Geib, F.D.; Rapp, R.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering)

1992-11-01

145

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

SciTech Connect

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.

Dulam, C.S.; Hoag, G.E.; Dahmani, A.; Nadim, F. [Univ. of Connecticut, Storrs, CT (United States). Environmental Research Inst.

1996-11-01

146

Fuzzy Decision Modeling of Product Development Processes  

Microsoft Academic Search

\\u000a Product development has become a focus of competition in many industries. Due to decreasing product life cycle, it is important\\u000a to reduce the time and cost of product development. The product development process includes six main phases: product planning,\\u000a concept development, system-level design, detailed design, testing and refinement, and production ramp-up [34]. Concept development process consists of four stages: identifying

Juite Wang; Andrew Kusiak

147

Wood Technology: Techniques, Processes, and Products  

ERIC Educational Resources Information Center

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…

Oatman, Olan

1975-01-01

148

XML-based product information processing method for product design  

NASA Astrophysics Data System (ADS)

Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.

Zhang, Zhen Yu

2012-01-01

149

XML-based product information processing method for product design  

NASA Astrophysics Data System (ADS)

Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.

Zhang, Zhen Yu

2011-12-01

150

Injectable bone cement based on mineralized collagen.  

PubMed

A novel injectable bone cement based on mineralized collagen was reported in this paper. The cement was fabricated by introducing calcium sulfate hemihydrate (CaSO(4).1/2H(2)O, CSH) into nano-hydroxyapatite/collagen (nHAC). The workability, in vitro degradation, in vitro and in vivo biocompatibility of the cement (nHAC/CSH) were studied. The comparative tests via in vitro and in vivo showed that the nHAC/CSH composite cement processed better biocompatibiltiy than that of pure CSH cement. The results implied that this new injectable cement should be very promising for bone repair. PMID:20336741

Liu, Xi; Wang, Xiu-Mei; Chen, Zonggang; Cui, Fu-Zhai; Liu, Huan-Ye; Mao, Keya; Wang, Yan

2010-07-01

151

Blended cement using volcanic ash and pumice  

Microsoft Academic Search

This paper reports the results of investigation to assess the suitability of volcanic ash (VA) and pumice powder (VPP) for blended cement production. Tests were conducted on cement where Portland cement (PC) was replaced by VA and VPP within the range of 0 to 50%. The physical and chemical properties of VA and VPP were critically reviewed to evaluate the

Khandaker M. Anwar Hossain

2003-01-01

152

Influence of ferrite phase in alite-calcium sulfoaluminate cements  

NASA Astrophysics Data System (ADS)

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.

Duvallet, Tristana Yvonne Francoise

153

Speciality cements with advanced properties  

SciTech Connect

The subject matter, specialty cements with advanced properties, highlight some of the recent progress in the non-standard cementitious systems. The topic was intended to be broad enough to include MDF and DSP cement, as well as phosphate-based and other binders. The response to this broad request resulted in a wide variational sampling of potential binder systems, which included calcium phosphates, magnesium phosphates, silica systems derived from sodium fluosilicates, stratlingite glasses, alkali-activated blended cements, and aluminophosphates. Presentations also addressed in depth, the underlying processing and fundamental insight into macro defect cements and DSP.

Scheetz, B.E. (Pennsylvania State Univ., University Park, PA (United States)); Landers, A.G. (Armstrong World Industries, Lancaster, PA (US)); Odler, I. (Technische Univ., Clausthal (DE)); Jennings, H. (Northwestern Univ., Evanston, IL (United States))

1991-01-01

154

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

Microsoft Academic Search

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.

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

2008-01-01

155

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

PubMed

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

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

2011-10-01

156

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

PubMed Central

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 ?m fraction subsample were analyzed to obtain the elemental source profile. The particle deposition flux in the study area was higher (24–83 mg/m2 day) than at the background sites (13–17 mg/m2·day). 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

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

2014-01-01

157

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

SciTech Connect

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.

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

1994-10-01

158

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

SciTech Connect

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.

Not Available

1990-12-31

159

Product Innovation, Process Innovation, and Size  

Microsoft Academic Search

We test the hypothesis that large firms devote a higher proportion of their research and development (R & D) expenditure on process innovation thansmaller firms. According to the estimates, process- and product R & D expenditure rise less than in proportion to size. The size effect is somewhat stronger for process R & D but the difference to product R

Michael Fritsch; Monika Meschede

2001-01-01

160

Modeling of Integrated Product Development Processes  

Microsoft Academic Search

The development process has to be modeled and documented for its reengineering and continuous improvement. A development process model is the basis for how a system will be designed. Due to the special nature of integrated product devel- opment processes, a method for process modeling has to be able to support and easily map the high interconnectivity between processes of

Herbert Negele; Ernst Fricke; Lutz Schrepfer; Nicole Härtlein; BMW AG; München Germany

161

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

PubMed

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

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

2006-08-25

162

Basic studies on hydroxy apatite cement: I. Setting reaction.  

PubMed

Self-setting cements, alpha D-Cement and alpha DT-Cement, were prepared. They consisted of only the calcium phosphates alpha-TCP, TTCP and DCPA. These cements reacted and hardened in a moist environment at 37 degrees C. The powder X-ray diffraction patterns were taken to examine the conversion of their reactions as a function of time. The cements reacted and produced hydroxyapatite. The optimum powder/liquid ratio of alpha D-Cement was 2.0 and that of alpha DT-Cement was 1.8. The initial setting time of alpha D-Cement was 87.5 m and that of alpha DT-Cement was 107.5 m. The component and the product of these cements are calcium phosphates which are the putative minerals in teeth and bones. Therefore, these cements are useful for oral surgery as bone-filling materials. PMID:9680764

Fukase, Y; Wada, S; Uehara, H; Terakado, M; Sato, H; Nishiyama, M

1998-06-01

163

DATA PROCESSING PROCEDURES ALSEP PRODUCTION  

E-print Network

of Effective Pages Total number of pages in this document is 101 consisting of the following: Page number-11 Chart of moon positions. ALSEP data reduction request form. Typical labels of five data products

Rathbun, Julie A.

164

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

NASA Astrophysics Data System (ADS)

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.

Chen, Irvin Allen

165

Productivity enhancement through process integration  

E-print Network

between reactor yield and process yield???????????????????????.. 3 2.1 Graphical representation of the HEN synthesis task????????. 9 2.2 Graphical representation of single mass exchanger????...???? 12 2.3 Mass Exchange Network (MEN... 2.7 Graphical representation of HIWAMIN and EIWAMIN synthesis??.. 18 4.1 General process scheme to differentiate between reactor yield and process yield???????????????????????.. 47 4.2a Evaluating feed to reactor...

Alotaibi, Meteab Aujian

2006-10-30

166

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

NASA Astrophysics Data System (ADS)

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 ?4.8 × 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.

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

2014-12-01

167

Generative inspection process planner for integrated production  

SciTech Connect

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.

Brown, C.W. (Allied-Signal Aerospace Co., Kansas City, MO (USA). Kansas City Div.) [Allied-Signal Aerospace Co., Kansas City, MO (USA). Kansas City Div.; Gyorog, D.A. (Kansas Univ., Lawrence, KS (USA). Dept. of Mechanical Engineering) [Kansas Univ., Lawrence, KS (USA). Dept. of Mechanical Engineering

1990-04-01

168

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

Microsoft Academic Search

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·3Al2O3·SO3) and dicalcium silicate (2CaO·SiO2) at ?1250°C if nodulized raw meal is

P. Arjunan; Michael R. Silsbee; Della M. Roy

1999-01-01

169

Integration of software process and product quality  

SciTech Connect

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.

Schneidewind, N.F. [Naval Postgraduate School, Monterey, CA (United States)

1996-12-31

170

The virtual cement plant - the benefits and technology of simulators  

Microsoft Academic Search

Today, employing well qualified control room operators, engineers, and support personnel, is an economic necessity for cement manufacturers. Training is the only way to achieve higher qualification, resulting in immediate financial benefits for the modern cement producers. This paper will describe a progressive tool for such process related training: a SIMULATOR, tailor-made for the cement industry. A cement plant simulator

Thomas Binninger

2004-01-01

171

Cementation of Upper Miocene reefs in western Mediterranean  

Microsoft Academic Search

Coral reefs in the western Mediterranean (southeast Spain, Balearic Island, northern Morocco, Sicily, and Italy) show a wide variety of cement types, ranging from completely tight, well-cemented, to poorly cemented reefs with most of the primary porosity still preserved. Cementation processes in those coral reefs appear to be controlled to a great extent by repeated changes of relative sea levels

M. Esteban; F. Calvet

1983-01-01

172

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

SciTech Connect

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.

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

1999-08-01

173

New textile product development: Processes, practices, and products  

Microsoft Academic Search

With today's global competitive marketplace, new textile product development requires a design, marketing, materials and technology interface. An opportunity existed to examine the new textile product development processes being used by global textile companies with a variety of textile product end-uses: apparel, home textiles, transportation, industrial, nonwovens, carpets, and medical textiles. The Crawford and DiBenedetto model (2003) was used as

N. B. Powell; N. L. Cassill

2006-01-01

174

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

Microsoft Academic Search

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

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

2012-01-01

175

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

SciTech Connect

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.

Jarabo, Rocio; Fuente, Elena; Moral, Ana; Blanco, Angeles [Chemical Engineering Department, University Complutense of Madrid. Avda. Complutense s/n, Madrid 28040 (Spain); Izquierdo, Laura [I-D Department, TOLSA S.A., Rd. Vallecas-Mejorada del Campo, Km 1600, Madrid 28031 (Spain); Negro, Carlos, E-mail: cnegro@quim.ucm.e [Chemical Engineering Department, University Complutense of Madrid. Avda. Complutense s/n, Madrid 28040 (Spain)

2010-10-15

176

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

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

177

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...

178

Treatment and recycling of asbestos-cement containing waste  

Microsoft Academic Search

The remediation of industrial buildings covered with asbestos-cement roofs is one of the most important issues in asbestos risk management. The relevant Italian Directives call for the above waste to be treated prior to disposal on landfill. Processes able to eliminate the hazard of these wastes are very attractive because the treated products can be recycled as mineral components in

F. Colangelo; R. Cioffi; M. Lavorgna; L. Verdolotti; L. De Stefano

2011-01-01

179

Development of corn cob ash blended cement  

Microsoft Academic Search

In an attempt to convert waste product into useful material for the construction industry, this research considered the use of corn cob ash (CCA) as a pozzolan in cement production. The study investigated the chemical composition of CCA. Factory production of the CCA – blended cement was carried out by replacing 0%, 2%, 4%, 6%, 8%, 10%, 15%, 20% and

D. A. Adesanya; A. A. Raheem

2009-01-01

180

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

Microsoft Academic Search

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

A Maimoni

1982-01-01

181

Accelerated ageing of blended OPC cements  

SciTech Connect

An accelerated experimental technique using high water:cement ratios has been developed to study the long term hydration of blended cements that may be used in a repository for the disposal of radioactive waste. This technique has been used to investigate the hydration reactions of Ordinary Portland Cement (OPC) blended with ground granulated blastfurnace slag (ggbs) or pulverised fuel ash (pfa). The effects of high sulphate-bearing and high carbonate-bearing ground waters on the compounds formed on hydration were investigated. Solid/solution compositional data were collected during the course of the hydration process for periods up to 2 years. Thomsonite, thaumasite, afwillite and a tobermorite-like phase were found in addition to the expected cement hydration products. The pH of the aqueous solution in contact with 60 pfa:40 OPC blends hydrated at 90{degrees}C fell to below 8. This is lower than the value required to inhibit the corrosion of steel canisters in a repository. The pH of the aqueous solution in contact with OPC and 75 ggbs:25 OPC blends remained above 11, although if the ground waters in contact with the OPC/ggbs blends were periodically replaced the pH eventually fell below 10.

Quillin, K.C.; Duerden, S.L.; Majumdar, A.J. [Building Research Establishment, Herts (United Kingdom)

1994-12-31

182

Process for improving metal production in steelmaking processes  

DOEpatents

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.

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

1996-01-01

183

Process for improving metal production in steelmaking processes  

DOEpatents

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.

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

1996-06-18

184

Cement industry: sustainability, challenges and perspectives  

Microsoft Academic Search

Cement-based materials, such as concrete and mortars, are used in extremely large amounts. For instance, in 2009 concrete\\u000a production was superior to 10 billion tons. Cement plays an important role in terms of economic and social relevance since\\u000a it is fundamental to build and improve infrastructure. On the other hand, this industry is also a heavy polluter. Cement production\\u000a releases

F. A. Rodrigues; I. Joekes

2011-01-01

185

Bacterial Production Lab State variables and processes  

E-print Network

: Bacterial Growth Rate (gC h-1) Why do we want to measure processes? Objective: Measure bacterial growth rateBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 G. Process #12;Growth Equations dt tt txtx 0 20 )()( td Where: td Doubling time of population. x(t) Number

Vallino, Joseph J.

186

Bacterial Production Lab State variables and processes  

E-print Network

B: Bacterial Growth Rate (gC h-1) Why do we want to measure processes? Objective: Measure bacterial growth rateBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 r Var. Process #12;Growth Equation td Where: td Doubling time of population. x(t) Number or mass

Vallino, Joseph J.

187

Bacterial Production Lab State variables and processes  

E-print Network

: Bacterial Growth Rate (gC h-1) Why do we want to measure processes? Objective: Measure bacterial growth rateBacterial Production Lab State variables and processes BDOM Other compounds (e.g., EtOH) CO2 G. Process #12;Growth Equations dt tt txtx 0 20 - = )()( td Where: td Doubling time of population. x

Vallino, Joseph J.

188

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

DOEpatents

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.

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

1989-01-01

189

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

DOEpatents

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.

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

1988-05-04

190

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

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.

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

191

Retrieval processes in arithmetic production and verification.  

PubMed

To investigate whether arithmetic production and verification involve the same retrieval processes, we alternated multiplication production trials (e.g., 9 x 6 = ?) with verification trials (4 x 9 = 36, true or false?) and analyzed positive error priming. Positive error priming is the phenomenon in which errors frequently match correct answers from preceding problems. Production errors were strongly primed by previous production trials (the error-answer matching rate was about 90% greater than expected by chance), but production errors were not strongly primed by previous verification trials (approximately 13% above chance). Conversely, false-verification errors were primed by previous verification trials (approximately 25% above chance), but not by production trials. The results indicated that arithmetic production and verification were mediated by different memory processes and suggest a familiarity-based over a retrieval-based model of arithmetic verification. PMID:8881320

Campbell, J I; Tarling, D P

1996-03-01

192

A cement kiln flue-dust evaluated as a soil liming material  

E-print Network

A CEMENT KILN FLUE-DUST EVALUATED AS A SOIl LIMING MATERIAL A Thesis by RAIMUND STACHA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE 1973 NJSbj t.... Such is the case with "flue-dust" materials formed in portland cement production processes. Since this flue-dust material has a 78. 67. CaCO& equivalent, it may have promise as an agricultural liming material. The use of industrial cement kiln by...

Stacha, Raimund

1973-01-01

193

Temperature Control in Cement Rotary Kiln with Neural Network-Based Heuristic Dynamic Programming  

Microsoft Academic Search

During the production process of modern cement industry, the rotary kiln is the key equipment .The temperature of cement rotary\\u000a kiln is a large lag, large inertia, complex nonlinear controlled object. There are many external factors influencing the temperature,\\u000a and there exist coupling and uncertainties among various factors. Approximate Dynamic Programming (ADP) is an on line control\\u000a approach that based

Xiaofeng Lin; Tangbo Liu; Deguang Cao; Qingbao Huang

2009-01-01

194

High-temperature wear of cemented tungsten carbide tools while machining particleboard and fiberboard  

Microsoft Academic Search

Published research on the wear processes of cemented tungsten carbide tools used for machining reconstituted wood products\\u000a was reviewed, and the current state of knowledge in this area was evaluated. Underlying assumptions and conclusions regarding\\u000a high-temperature oxidation\\/corrosion wear during machining were examined in view of known reaction kinetics of cemented tungsten\\u000a carbide alloys in oxidative and corrosive environments at temperatures

Jannal Y. Sheikh-Ahmad; J. A. Bailey

1999-01-01

195

Advanced Multi-Product Coal Utilization By-Product Processing Plant  

SciTech Connect

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.

Thomas Robl; John Groppo

2009-06-30

196

Mariner 9-Image processing and products  

USGS Publications Warehouse

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.

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

197

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

PubMed Central

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

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

2005-01-01

198

Cell culture processes for monoclonal antibody production  

PubMed Central

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

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

2010-01-01

199

The nature of CSH in hardened cements  

Microsoft Academic Search

Calcium silicate hydrates (C-S-H) are the main binding phases in all Portland cement-based systems. This paper considers the morphology, composition, and nanostructure of C-S-H in a range of hardened cements. Inner product (Ip) C-S-H present in larger Portland cement grains typically has a fine-scale and homogeneous morphology with pores somewhat under 10 nm in diameter. Ip from larger slag grains

I. G Richardson

1999-01-01

200

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

SciTech Connect

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.

Chen, Cheng-Gang [Department of Water Resources and Environmental Engineering, Tamkang University, 151, Ying-chung Road, Tamsui Dist., New Taipei City 251, Taiwan, ROC (China); Sun, Chang-Jung, E-mail: sun.3409@hotmail.com [Department of Environmental Technology and Management, Taoyuan Innovation Institute of Technology, 414, Sec. 3, Jhongshan E. Rd., Zhongli City, Taoyuan County 320, Taiwan, ROC (China); Gau, Sue-Huai; Wu, Ching-Wei; Chen, Yu-Lun [Department of Water Resources and Environmental Engineering, Tamkang University, 151, Ying-chung Road, Tamsui Dist., New Taipei City 251, Taiwan, ROC (China)

2013-04-15

201

Continuous process of production of pentaerythritol  

SciTech Connect

To meet the rising needs of the national economy for pentaerythritol, used in the production of alkyd resins, polyurethane foams, ester lubricants, and so forth, it is necessary to set up large-tonnage continuous production meeting the modern level of technology with a precise system of automatic process control. A continuous method for production of pentaerythritol in the presence of sodium hydroxide has been developed at the Uralkhimplast production association. The technology of the process was tested and developed on an experimental-industrial installation in the present pentaerythritol plant. The basic merit of the continuous process for production of pentaerythritol using NaOH as catalyst over the traditional method based on calcium hydroxide as catalyst, besides the increase of productivity, is the simpler technological scheme of the process. In the continuous production of pentaerythritol, the steps of catalyst preparation (roasting of limestone, slaking of lime, preparation of milk of lime), vacuum filtration of the condensation solution to remove gypsum (elimination of solid wastes in the form of gypsum) are eliminated. In addition, the specific consumption of acetaldehyde, formaldehyde, formic acid, electric power and steam is reduced. A characteristic distinction of the process using sodium hydroxide from that using calcium hydroxide is the fact that the condensation solutions produced in the former case are almost colorless and do not change color at the end of the reaction. Therefore, the finished product produced in the presence of NaOH is superior with regard to physicochemical properties to that produced in the presence of Ca(OH)/sub 2/.

Pakulin, V.V.; Rogachev, Y.V.; Gulevich, P.E.; Kruglikov, A.A.

1982-12-01

202

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

PubMed

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 (C3S) 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+ attacks on cement phases and the precipitation of calcium heavy metal double hydroxides, which consumes calcium ions and then promotes the decomposition of C3S. In this work, molecular models of calcium silicate hydrate gel are presented based on the examination of 29Si 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. PMID:18367391

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

2009-01-01

203

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

SciTech Connect

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.

Chen, Q.Y. [School of Environmental Science and Engineering, Donghua University, Shanghai 200051 (China)], E-mail: qychen@dhu.edu.cn; Tyrer, M. [Department of Materials, Imperial College of Science, Technology and Medicine, London SW7 4AZ (United Kingdom); Hills, C.D. [Centre for Contaminated Land Remediation, Medway School of Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB (United Kingdom); Yang, X.M. [School of Environmental Science and Engineering, Donghua University, Shanghai 200051 (China); Carey, P. [Centre for Contaminated Land Remediation, Medway School of Science, University of Greenwich, Chatham Maritime, Kent ME4 4TB (United Kingdom)

2009-01-15

204

Improving efficiency in product and process development : a case study on a consumer products creation process  

E-print Network

This research examines how an athletic footwear company should establish its new product development and launch process to eliminate wastes in the processes and improve the time to market. Currently, it typically takes an ...

Dong, Xiaoqin, 1971-

2004-01-01

205

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

PubMed

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

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

2013-01-01

206

In-vitro Comparison of the Antimicrobial Properties of Glass Ionomer Cements with Zinc Phosphate Cements  

PubMed Central

White spot lesions are observed in nearly 50% of patients undergoing orthodontic treatment. Long-lasting antibacterial properties of orthodontic cements can reduce this phenomenon. The aim of this research was to compare antimicrobial activity of three commercial glass ionomer cements with three commercial zinc phosphate cements, over time, against streptococcus mutans and candida albicans. Direct contact test (DCT) was used to evaluate the antibacterial and antifungal activity of products after 48 h and 7 days of incubation. The results demonstrated that all the cements presented antibacterial activity but the antibacterial activity of glass ionomer cements was more than that of zinc phosphate cements. Counts of C. albicans after 48 h were lower and statistically different in the GIC group in relation to the control groups. But no differences were observed between GIC and control groups at 7 days. Based on the results of this study, the antimicrobial and mainly antifungal effects of all the cements were so short. PMID:25317187

Vahid Dastjerdie, Elaheh; Oskoui, Mahvash; Sayanjali, Elham; Tabatabaei, Fahimeh Sadat

2012-01-01

207

Influence of granule properties and concentration on cork-cement compatibility  

Microsoft Academic Search

Cork granules are produced as by-products and waste by the cork processing industries that make ‘bottle stoppers’ as a main product. These granules are of low density and could be used as lightweight aggregates for making concrete. This paper describes an investigation carried out to assess the compatibility of cork granules with cement for the manufacture of lightweight cementitious composites.

Sukhdeo R. Karade; Mark Irle; Kevin Maher

2006-01-01

208

New polymer additives for mortar cement  

SciTech Connect

Mortar cement is a hydraulic cement similar to masonry cement in use and function, introduced to enhance one or more of the latter's properties, such as workability, durability, and water retention. In addition, mortar cement must have lower air content and it has minimum flexural bond strength requirements. In response to fulfilling these needs, a new family of water soluble polymers has been developed. The new polymer additives are designed to optimize air void distribution and rheology of wet mortar, allowing improved workability with low air content. Furthermore, these polymers impart high water retention to the mortar, and allow the production of mortar with enhanced board life and flexural bond strength.

Chu, S.G.; Podlas, T.J.; Young, T.S.

1999-07-01

209

Overcoming interpretation problems of gas-contaminated cement using ultrasonic cement logs  

SciTech Connect

The primary objective of cement sheath evaluation logs is to determine whether the production or injection zones, as well as other critical zones, are hydraulically isolated. Ultrasonic measurements have been used in cement evaluation since the early 1980s. Ultrasonic tools evaluate the cement sheath by measuring the acoustic impedance of the material outside the casing. Cement has a higher acoustic impedance than drilling fluids or water, and gas has an acoustic impedance near zero. Gas-contaminated cement poses the main problem in interpretation of ultrasonic cement tools. To understand the problem, the acoustic impedance of what might be in the casing-to-formation annulus must be considered. The acoustic impedance of cement can range from slightly over 3.0 MRayl to about 7.0 MRayl. Drilling fluids can be 1.5 MRayl to 3.0 MRayl. Water has an acoustic impedance of 1.5, and gas has an acoustic impedance of less than 0.04 MRayl. As long as there is sufficient difference between the acoustic impedance of the cement and the acoustic impedance of the liquid phase, channels in the cement can quickly be identified. In the case of gas-cut cement the texture of the material tends to be that of a honeycomb. This paper proposes a technique for using high-resolution ultrasonic data to identify gas-contaminated cement, while maintaining nearly the same vertical and radial resolution, thus allowing the identification of liquid-and gas-filled channels. The proposed technique allows improved interpretation of the high-resolution ultrasonic data when gas-contaminated cement is encountered. Even when attenuation-type logs are run, this technique will aid the interpretation. The results to date indicate that this technique can be applied to eliminate unnecessary cement squeeze jobs caused by misinterpretation of the ultrasonic data. Examples are shown to compare the technique to other cement log data and cement squeeze results.

Butsch, R.J.

1995-12-31

210

Mass balance of dioxins over a cement kiln in China.  

PubMed

The cement production process may be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, "dioxins"), due to the widespread distribution of dioxins and potential precursors in raw materials and to conditions favorable to de novo formation in the heat exchangers. The emission, gas/particle distribution, and mass balance of PCDD/Fs were investigated at a typical state-of-the-art Chinese cement kiln. Input and output inventories were established for three campaigns, including two in normal operation and one while co-processing refuse derived fuel (RDF). Sample analysis from stack gas, cement kiln dust, raw meal, fly dust and clinker for the analysis of PCDD/Fs were reported in this study. Dioxins were also analyzed at various positions in the pre-heater, presenting an adsorption-desorption circulation process of PCDD/Fs. The over-all dioxin mass balance was negative, indicating that this cement kiln is not a source but a sink process of dioxins. PMID:25532674

Li, Yeqing; Chen, Tong; Zhang, Jiang; Meng, Weijie; Yan, Mi; Wang, Huanzhong; Li, Xiaodong

2015-02-01

211

CELLULOSE CEMENT COMPOSITE MODIFIED BY POLYMER  

Microsoft Academic Search

The durability of the cellulose-cement composites is a deciding factor to introduce such material in the market. Several researches have been developed aiming to avoid the degradation of vegetable fiber-cement, some using chemically treated fibers and others modifying the matrix. Polymers have been used in concrete and mortar production to increase its durability. The goal of this work is to

L. L. Pimentel; A. L. Beraldo; H. Savastano Jr

212

Syllables as Processing Units in Handwriting Production  

ERIC Educational Resources Information Center

This research focused on the syllable as a processing unit in handwriting. Participants wrote, in uppercase letters, words that had been visually presented. The interletter intervals provide information on the timing of motor production. In Experiment 1, French participants wrote words that shared the initial letters but had different syllable…

Kandel, Sonia; Alvarez, Carlos J.; Vallee, Nathalie

2006-01-01

213

Process for the production of ammonia  

Microsoft Academic Search

A process for the production of ammonia, comprising the steps of: gasifying a feedstock containing carbon and a source of hydrogen with air as the only source of free oxygen, to produce a raw synthesis gas comprising nitrogen, hydrogen, carbon oxides, and methane; subjecting the raw synthesis gas to a shift conversion reaction; removing the carbon oxides from the shift

Banquy

1985-01-01

214

Scleroglucan: Fermentative Production, Downstream Processing and Applications  

Microsoft Academic Search

Summary Exopolysaccharides produced by a variety of microorganisms find multifarious indus- trial applications in foods, pharmaceutical and other industries as emulsifiers, stabilizers, binders, gelling agents, lubricants, and thickening agents. One such exopolysaccharide is scleroglucan, produced by pure culture fermentation from filamentous fungi of genus Scle- rotium. The review discusses the properties, fermentative production, downstream process- ing and applications of scleroglucan.

Shrikant A. Survase; Parag S. Saudagar; Ishwar B. Bajaj; Rekha S. Singhal

215

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...

216

Corn processing coproducts from ethanol production  

Microsoft Academic Search

Increase in demand for ethanol as a fuel additive has resulted in growth in ethanol production. Ethanol is produced from corn by either wet milling or dry grind processing. In wet milling, the corn kernel is fractionated into different components, resulting in several coproducts. Wet mill plants are capital intensive because of equipment requirements and typically are corporate owned. In

Kent D. Rausch; Ronald L. Belyea; Vijay Singh; M. E. Tumbleson

2007-01-01

217

A supervisory fuzzy control of back-end temperature of rotary cement kilns  

Microsoft Academic Search

Rotary Kiln is the central and the most complex components of cement production process. The first point at the beginning of the process, which is called back-end, is the calcining zone of the kiln and has a significant role on the quality of the clinker. In this paper to control the back-end temperature of a rotary kiln, we propose a

Maryam Fallahpour; Alireza Fatehi; Babak N. Araabi; Morteza Azizi

2007-01-01

218

Energy-saving cements obtained from chemical gypsum and other industrial wastes  

Microsoft Academic Search

The main sources, properties and uses of chemical gypsum are reviewed and the possibility of its utilization for the manufacturing process of calcium sulphoaluminate cements is explored. In this process other industrial wastes, as sources of reactive silica and alumina, can be employed. Phosphogypsum, blast-furnace slag and fly ash were the main by-products investigated. The principal properties of calcium sulphoaluminate

M. Marroccoli; G. L. Valenti

1996-01-01

219

Portland cements characterized, evaluated  

Microsoft Academic Search

This article discusses behavior during placement in the well and longterm stability after the cement has set, with emphasis on the chemical and physical nature of the cement itself. Presents graphs showing particle size distribution and hydration of CâS vs. time. Summarizes the current understanding of cement chemistry as applied to oil well cementing. Points out that the principal deficiencies

1983-01-01

220

Properties of volcanic pumice based cement and lightweight concrete  

Microsoft Academic Search

The results of investigations on the suitability of using volcanic pumice (VP) as cement replacement material and as coarse aggregate in lightweight concrete production are reported. Tests were conducted on cement by replacing 0% to 25% of cement by weight and on concrete by replacing 0% to 100% of coarse aggregate by volume. The physical and chemical properties of VP

Khandaker M Anwar Hossain

2004-01-01

221

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2002-07-30

222

CEMENT RELATED RESEARCH HYDROGEOCHEMISTRY GROUP  

E-print Network

CEMENT RELATED RESEARCH HYDROGEOCHEMISTRY GROUP Josep M. Soler Jordi Cama Carles Ayora Ana Trapote.soler@idaea.csic.es #12;NOMECLATURE cement + water = hardened cement paste cement + water + sand = mortar cement + waterC) clinker + gypsum portland cement PORTLAND CEMENT #12;GTS-HPF Core Infiltration Experiment Experimental

Politècnica de Catalunya, Universitat

223

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

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.

Snellings, R., E-mail: ruben.snellings@ees.kuleuven.b [Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B-3001 Heverlee (Belgium); Mertens, G. [Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B-3001 Heverlee (Belgium); Cizer, O. [Department of Civil Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 40, B-3001 Heverlee (Belgium); Elsen, J. [Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B-3001 Heverlee (Belgium)

2010-12-15

224

Research of magnesium phosphosilicate cement.  

E-print Network

??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)… (more)

Ding, Zhu

2005-01-01

225

Simulation assisted capacity improvement of cement grinding circuit: Case study cement plant  

Microsoft Academic Search

Extensive sampling campaign was performed around the cement grinding circuit of a cement plant in Turkey, for different production types of cement, as CEM I 42.5, CEM II 32.5\\/42.5\\/52.5, for the modelling and simulation purposes. During the sampling surveys; samples were collected from around the circuit for the steady state condition of the operation and, following a crash stop, from

H. Dundar; H. Benzer; N. A. Aydogan; O. Altun; N. A. Toprak; O. Ozcan; D. Eksi; A. Sarg?n

2011-01-01

226

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

SciTech Connect

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.

SUGAMA,T.; BROTHERS, L.E.

2005-01-01

227

Multiphase Flow Modeling of Biofuel Production Processes  

SciTech Connect

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.

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

2011-06-01

228

USE OF VATERITE AND CALCITE IN FORMING CALCIUM PHOSPHATE CEMENT A. Cuneyt Tas  

E-print Network

USE OF VATERITE AND CALCITE IN FORMING CALCIUM PHOSPHATE CEMENT SCAFFOLDS A. Cuneyt Tas Department calcium phosphate (CaP+CaCO3) cements have been developed. The common point in these cements in the end-product of these cements was carbonated, Ca-deficient, apatitic calcium phosphate, together

Tas, A. Cuneyt

229

Amphoteric surfactants: processing, product composition and properties.  

PubMed

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

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

1997-10-01

230

Measurement of transient and residual stresses during polymerization of bone cement for cemented hip implants.  

PubMed

The initial fixation of a cemented hip implant relies on the strength of the interface between the stem, bone cement and adjacent bone. Bone cement is used as grouting material to fix the prosthesis to the bone. The curing process of bone cement is an exothermic reaction where bone cement undergoes volumetric changes that will generate transient stresses resulting in residual stresses once polymerization is completed. However, the precise magnitude of these stresses is still not well documented in the literature. The objective of this study is to develop an experiment for the direct measurement of the transient and residual radial stresses at the stem-cement interface generated during cement polymerization. The idealized femoral-cemented implant consists of a stem placed inside a hollow cylindrical bone filled with bone cement. A sub-miniature load cell is inserted inside the stem to make a direct measurement of the radial compressive forces at the stem-cement interface, which are then converted to radial stresses. A thermocouple measures the temperature evolution during the polymerization process. The results show the evolution of stress generation corresponding to volumetric changes in the cement. The effect of initial temperature of the stem and bone as well as the cement-bone interface condition (adhesion or no adhesion) on residual radial stresses is investigated. A maximum peak temperature of 70 degrees C corresponds to a peak in transient stress during cement curing. Maximum radial residual stresses of 0.6 MPa in compression are measured for the preheated stem. PMID:18692188

Nuño, N; Madrala, A; Plamondon, D

2008-08-28

231

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

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.

Boden, T.A.; Marland, G. [Oak Ridge National Lab., TN (United States); Andres, R.J. [University of Alaska, Fairbanks, AK (United States). Inst. of Northern Engineering

1995-12-01

232

A Blackboard Architecture for Integrating Process Planning and Production Scheduling  

E-print Network

process plans and (2) quickly integrate process plans for new orders into the existing production schedule a decoupled approach to building process planning/production scheduling solutions. Relevant keywords: PROCESS) quickly integrate process plans for new orders into existing production schedules to best accommodate

Sadeh, Norman M.

233

In situ vitrification: Process and products  

SciTech Connect

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.

Kindle, C.; Koegler, S.

1991-06-01

234

Power Ultrasound to Process Dairy Products  

NASA Astrophysics Data System (ADS)

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.

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

235

Advanced Multi-Product Coal Utilization By-Product Processing Plant  

SciTech Connect

The objective of the project is to build a multi-product ash beneficiation plant at Kentucky Utilities 2,200-MW Ghent Generating Station, located in Carroll County, Kentucky. This part of the study includes an investigation of the secondary classification characteristics of the ash feedstock excavated from the lower ash pond at Ghent Station. The secondary classification testing was concluded using a continuous demonstration-scale lamella classifier that was operated at a feed rate of 0.3 to 1.5 tons/hr. Feed to the secondary classifier was generated by operating the primary classifier at the conditions shown to be effective previously. Samples were taken while the secondary classifier was operated under a variety of conditions in order to determine the range of conditions where the unit could be efficiently operated. Secondary classification was effective for producing an ultra-fine ash (UFA) product. Inclined lamella plates provided an effective settling surface for coarser ash particles and plate spacing was shown to be an important variable. Results showed that the closer the plate spacing, the finer the size distribution of the UFA product. Flotation of the secondary classifier feed provided a lower LOI UFA product (2.5% LOI vs. 4.5% LOI) and a dispersant dosage of 2 to 2.5 g/kg was adequate to provide UFA grade (3.8 to 4.4 {micro}m) and recovery (53 to 68% 5{micro}m recovery). The UFA yield without flotation was {approx}33% and lower ({approx}20%) with flotation. Demonstration plant product evaluations showed that water requirements in mortar were reduced and 100% of control strength was achieved in 28 days for the coarser products followed by further strength gain of up to 130% in 56 days. The highest strengths of 110% of control in 7 days and 140% in 56 days were achieved with the finer products. Mortar air requirements for processed products were essentially the same as those for standard mortar, suggesting that the unburned carbon remaining does not have an affinity for air entraining admixture (AEA), a consideration that is a significant benefit. In concrete, substitution of 20% showed that the UFA product outperformed a typical ash by achieving 105 to 107% of control strength after 28 days and 109.5 to 112% after 56 days. Higher substitution levels were shown to delay early strength development, but surpass control strength after 28 days while lower substitution levels provide both early and longer term strength. One of the most significant benefits provided by using UFA in concrete mix designs is the improved resistance to chloride permeability while some improvements is flexural strength were realized and tensile strength was essentially unchanged. Potentially significant benefits may also be offered by using UFA as a process addition in the manufacture of cement clinker.

John Groppo; Thomas Robl; Robert Rathbone

2006-06-01

236

Process for production of a metal hydride  

SciTech Connect

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.

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

2014-08-12

237

Cellulase production by the anaerobic digestion process  

SciTech Connect

An anaerobic digestion process is described for the production of cellulolytic enzymes using a methanogenic cellulose-enrichment culture. After a heat treatment designed to destroy all but spore-forming bacteria, this culture produced cellulase from a variety of cellulosic materials as well as from cellobiose. The enzyme system contained endo- and exoglucanase, acted on filter paper, and showed cellobiase and xylanase activities. It was stable at 2/sup 0/C under aerobic conditions and showed a pH optimum at 5 and a temperature optimum at 50/sup 0/C. Endoglucanase and filter paper activities were mostly exogenic, whereas cellobiase and xylanase activities were cell associated. The cellulolytic activity produced by this mixed culture was comparable to that of commercially available fungal preparations, and the process could be useful as an alternate source for these enzymes.

Khan, A.W.; van den Berg, L.

1981-01-01

238

[ ]March 2013 The Louisiana Department ofTransportation and Development (DOTD) has been using cement  

E-print Network

using cement stabilized base course (soil cement) in flexible pavement construction for more than 50 on the cement stabilized base shortly after the base construction. The micro-cracks will help relieve the contracting stress of the cement stabilized layer during its drying process, thus preventing it from forming

Harms, Kyle E.

239

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

SciTech Connect

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.

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

240

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...

241

Do cement nanotubes exist?  

PubMed

Using atomistic simulations, this work indicates that cement nanotubes can exist. The chemically compatible nanotubes are constructed from the two main minerals in ordinary Portland cement pastes, namely calcium hydroxide and a calcium silicate hydrate called tobermorite. These results show that such nanotubes are stable and have outstanding mechanical properties, unique characteristics that make them ideally suitable for nanoscale reinforcements of cements. PMID:22589176

Manzano, H; Enyashin, A N; Dolado, J S; Ayuela, A; Frenzel, J; Seifert, G

2012-06-26

242

Thermcoat Cement INSTRUCTION  

E-print Network

CO and COL Thermcoat Cement INSTRUCTION SHEET M0101/0801 OMEGA® Thermcoat CO and COL consists of a powder (CO) and a liquid (COL) which, upon proper mixing, will yield a strong, insoluble cement. It has, which means it generates heat. For this reason, the heat must be dissipated or the cement will set too

Kleinfeld, David

243

Soy protein products: processing and use.  

PubMed

Soy protein products are mainly used as ingredients in formulated foods and seldom are seen by the public. They consist of four broad categories. (1) Most soy proteins are derived from "white flakes," made by dehulling, flaking and defatting soybeans by hexane extraction. These may then be milled into defatted flours or grits containing approximately 50-54% protein; extracted with ethanol or acidic waters to remove flavor compounds and flatulence sugars, producing soy protein concentrates containing 65-70% protein; or processed into soy protein isolates containing 90+% protein by alkali extraction of the protein, removal of fiber by centrifugation and reprecipitation and drying of the protein. (2) Full-fat products are made in enzyme-active and in toasted forms. (3) Various dried soyfoods, including soy milk and tofu, are produced. (4) Mixtures of soy proteins with cereals, dried milk or egg fractions, gelatin, stabilizers and emulsifiers are offered for specific baking, whipping, breading and batter applications. Texturized products, resembling meat chunks or bacon chips, are made by extrusion of flours and concentrates or spinning of isolates. Soy protein ingredients are used in compounded foods for their functional properties, including water and fat absorption, emulsification, aeration (whipping) and heat setting and for increasing total protein content and improving the essential amino acids profile. PMID:7884536

Lusas, E W; Riaz, M N

1995-03-01

244

Quartz cement in sandstones: a review  

NASA Astrophysics Data System (ADS)

Quartz cement as syntaxial overgrowths is one of the two most abundant cements in sandstones. The main factors that control the amount of quartz cement in sandstones are: framework composition; residence time in the "silica mobility window"; and fluid composition, flow volume and pathways. Thus, the type of sedimentary basin in which a sand was deposited strongly controls the cementation process. Sandstones of rift basins (arkoses) and collision-margin basins (litharenites) generally have only a few percent quartz cement; quartzarenites and other quartzose sandstones of intracratonic, foreland and passive-margin basins have the most quartz cement. Clay and other mineral coatings on detrital quartz grains and entrapment of hydrocarbons in pores retard or prevent cementation by quartz, whereas extremely permeable sands that serve as major fluid conduits tend to sequester the greatest amounts of quartz cement. In rapidly subsiding basins, like the Gulf Coast and North Sea basins, most quartz cement is precipitated by cooling, ascending formation water at burial depths of several kilometers where temperatures range from 60° to 100° C. Cementation proceeds over millions of years, often under changing fluid compositions and temperatures. Sandstones with more than 10% imported quartz cement pose special problems of fluid flux and silica transport. If silica is transported entirely as H 4SiO 4, convective recycling of formation water seems to be essential to explain the volume of cement present in most sandstones. Precipitation from single-cycle, upward-migrating formation water is adequate to provide the volume of cement only if significant volumes of silica are transported in unidentified complexes. Modeling suggests that quartz cementation of sandstones in intracratonic basins is effected by advecting meteoric water, although independent petrographic, isotopic or fluid inclusion data are lacking. Silica for quartz cement comes from both shale and sandstone beds within the depositional basin, including possibly deeply buried rocks undergoing low-grade metamorphism, but the relative importance of potential sources remains controversial and likely differs for different formations. The most likely important silica sources within unmetamorphosed shales include clay transformation (chiefly illitization of smectite), dissolution/pressure solution of detrital grains, and dissolution of opal skeletal grains; the most likely important sources of silica within unmetamorphosed sandstones include pressure solution of detrital quartz grains at grain contacts and at stylolites, feldspar alteration/dissolution, and perhaps carbonate replacement of silicate minerals and the margins of some quartz grains. Silica released by pressure solution in many sandstones post-dates the episode of cementation by quartz; thus, this silica must migrate and cement shallower sandstones in the basin or escape altogether. Some quartz-cemented sandstones are separated vertically from potential silica source beds by a kilometer or more, requiring silica transport over long distances. The similarity of diagenetic sequences in sandstones of different composition and ages apparently is the result of the normal temperature and time-dependent maturation of sediments, organic matter and pore fluids during burial in sedimentary basins. Silica that forms overgrowths is released by one or more diagenetic processes that apparently are controlled by temperature and time. Most cementation by quartz takes place when sandstone beds were in the silica mobility window specific to a particular sedimentary basin. Important secondary controls are introduced by compartmentalized domains produced by faults (e.g., North Sea) or overpressure boundaries (e.g., Gulf Coast Tertiary). Shallow meteoric water precipitates only small amounts of silica cement (generally less than 5% in most fluvial and colian sandstones), except in certain soils and at water tables in high-flux sand aquifers. Soil silcretes are chiefly cemented by opal and microcrystalline quartz, whereas water-tab

McBride, Earle F.

245

China: Emissions pattern of the world leader in CO2 emissions from fossil fuel consumption and cement production  

SciTech Connect

Release of carbon dioxide (CO2) from fossil fuel combustion and cement manufacture is the primary anthropogenic driver of climate change. Our best estimate is that China became the largest national source of CO2 emissions during 2006. Previously, the United States (US) had occupied that position. However, the annual emission rate in the US has remained relatively stable between 2001-2006 while the emission rate in China has more than doubled, apparently eclipsing that of the US in late 2006. Here we present the seasonal and spatial pattern of CO2 emissions in China, as well as the sectoral breakdown of emissions. Though our best point estimate places China in the lead position in terms of CO2 emissions, we qualify this statement in a discussion of the uncertainty in the underlying data (3-5% for the US; 15-20% for China). Finally, we comment briefly on the implications of China's new position with respect to international agreements to mitigate climate change.

Gregg, J [University of Maryland; Andres, Robert Joseph [ORNL; Marland, Gregg [ORNL

2008-01-01

246

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

Code of Federal Regulations, 2011 CFR

...processed in exempted egg products processing plants. 590.680 Section 590.680 Animals...INSPECTION ACT) Exempted Egg Products Plants § 590.680 Approval of labeling...processed in exempted egg products processing plants. (a) The labels for egg...

2011-01-01

247

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

Code of Federal Regulations, 2010 CFR

...processed in exempted egg products processing plants. 590.680 Section 590.680 Animals...INSPECTION ACT) Exempted Egg Products Plants § 590.680 Approval of labeling...processed in exempted egg products processing plants. (a) The labels for egg...

2010-01-01

248

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

Code of Federal Regulations, 2014 CFR

...processed in exempted egg products processing plants. 590.680 Section 590.680 Animals...INSPECTION ACT) Exempted Egg Products Plants § 590.680 Approval of labeling...processed in exempted egg products processing plants. (a) The labels for egg...

2014-01-01

249

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

Code of Federal Regulations, 2012 CFR

...processed in exempted egg products processing plants. 590.680 Section 590.680 Animals...INSPECTION ACT) Exempted Egg Products Plants § 590.680 Approval of labeling...processed in exempted egg products processing plants. (a) The labels for egg...

2012-01-01

250

The suitability of a supersulfated cement for nuclear waste immobilisation  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

251

Cement industry control system based on multi agent  

Microsoft Academic Search

Cement production is characterized by its great capacity, long-time delay, multi variables, difficult measurement and multi\\u000a disturbances. According to the distributed intelligent control strategy based on the multi agent, the multi agent control\\u000a system of cement production is built, which includes integrated optimal control and diagnosis control. The distributed and\\u000a multiple level structure of multi agent system for the cement

Hai-dong Wang; Guan-zhou Qiu; Sheng-sheng Huang

2004-01-01

252

INVESTIGATIONS ON HYDRAULIC CEMENTS FROM SPENT OIL SHALE  

SciTech Connect

A process for making hydraulic cements from spent oil shale is described in this paper. Inexpensive cement is needed to grout abandoned in-situ retorts of spent shale for subsidence control, mitigation of leaching, and strengthening the retorted mass in order to recover oil from adjacent pillars of raw shale. A hydraulic cement was produced by heating a 1:1 mixture of Lurgi spent shale and CaCO{sub 3} at 1000 C for one hour. This cement would be less expensive than ordinary portland cement and is expected to fulfill the above requirements.

Mehta, P.K.; Persoff, P.

1980-04-01

253

40 CFR 158.330 - Description of production process.  

Code of Federal Regulations, 2010 CFR

...REQUIREMENTS FOR PESTICIDES Product Chemistry § 158.330 Description...information on the production (reaction) processes used to produce...not continuous (a single reaction process from starting materials...equations of each intended reaction occurring at each step...

2010-07-01

254

40 CFR 161.162 - Description of production process.  

Code of Federal Regulations, 2010 CFR

...ANTIMICROBIAL PESTICIDES Product Chemistry Data Requirements § 161...information on the production (reaction) processes used to produce...not continuous (a single reaction process from starting materials...equations of each intended reaction occurring at each step...

2010-07-01

255

Phosphate-bonded calcium aluminate cements  

DOEpatents

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.

Sugama, T.

1993-09-21

256

Phosphate-bonded calcium aluminate cements  

DOEpatents

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.

Sugama, Toshifumi (Mastic Beach, NY)

1993-01-01

257

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2001-04-15

258

Optimal Multi-scale Capacity Planning for Power-Intensive Continuous Processes under  

E-print Network

is the group of power-intensive processes, such as air separation plants (compression), cement production (grinding), chlor-alkali synthesis, steel and aluminum production (electrolysis) and paper pulp pro- duction

Grossmann, Ignacio E.

259

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2001-07-18

260

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2002-04-29

261

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2002-10-31

262

Mineral of the month: cement  

USGS Publications Warehouse

Hydraulic cement is a virtually ubiquitous construction material that, when mixed with water, serves as the binder in concrete and most mortars. Only about 13 percent of concrete by weight is cement (the rest being water and aggregates), but the cement contributes all of the concrete’s compressional strength. The term “hydraulic” refers to the cement’s ability to set and harden underwater through the hydration of the cement’s components.

van Oss, Hendrik G.

2006-01-01

263

Atmospheric Processing Module for Mars Propellant Production  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

264

Atmospheric Processing Module for Mars Propellant Production  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

265

Product-level bill of material development process : managing complexity  

E-print Network

Cisco's current process for developing and maintaining product-level bills of materials (BOMs) has resulted in inconsistencies in BOM structure leading to product launch delays, increased product support costs, and lower ...

Lester, Ryan John

2009-01-01

266

Optical evaluation on the setting of cement paste  

NASA Astrophysics Data System (ADS)

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.

De León Martínez, H. A.; Bernal, J. J. Soto; González Mota, R.; Rosales-Candelas, I.

2015-01-01

267

Process for production of a borohydride compound  

DOEpatents

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.

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

2014-08-19

268

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

SciTech Connect

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)

Kascheev, Vladimir; Musatov, Nikolay [Joint Stock Company 'A.A. Bochvar High-Technology Scientific Research Institute of Inorganic Materials' (VNIINM), Rogova st., 5A (Russian Federation)

2012-07-01

269

The contemporary cement cycle of the United States  

USGS Publications Warehouse

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.

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

2009-01-01

270

Cementation and Neomorphism: Incorporating the Basics of Diagenesis into Any Sedimentary Geology Course  

NSDL National Science Digital Library

Two or three weeks of the course are dedicated to studying diagenesis. Lectures start with a general definition of diagenesis, the range of conditions under which it occurs, and examples of diverse diagenetic environments and features. I use rice crispy cereal and rice crispy treats to introduce cement (the marshmellow is the cement that "glues" the rice krispies together). I also incorporate basic hydrogeology to show how pores filled with (or partially filled with) groundwater provide both the space and the material for cementation. As part of this lecture, I show the students various rock samples and photomicrographs in which they can see cement examples. I outline the different cement minerals and shapes and how they can be used to interpret past diagenetic conditions (eg., gravitational "pendant" calcite cements indicate that the host sediment was once in a vadose zone with groundwater rich in calcium and carbonate). I also discuss types of pores during these lectures and the ways that pores form. We also discuss criteria for recognizing cements. After two one-hour lectures about cements, we have a lab exercise in which the students are given ~10 samples (including hand samples and thin sections) and asked to sketch and describe the cement types. The next one-hour lecture focuses on neomorphic processes and their products, including replacement, recrystallization, and polymorphic transition. As part of the lecture, we look at photomicrographs and hand samples that illstrate various neomorphic features, such as replacement dolomite and replacement chert. We establish criteria for distinguishing cements from neomorphic fabrics. This lecture is followed by a lab exercise that presents the students with ~10 rocks and thin sections and asks them to sketch and identify neomorphic fabrics. This lab is follwed by another one-hour lecture on compaction features, dissolution evidence, and determining paragentic sequences. If I am short on time, that is all I do for diagenesis. However, ideally, I continue with a lecture focused on the "dolomite problem" and some case studies of other types of diagenesis, as well as a third lab assignment that combines cementation, neomorphism, compaction, dissolution, and paragenetic sequences. As part of this section, I also try to incorporate examples of methods other than petrology (eg., fluid inclusion studies, stable isotope studies, dating) that are used for diagenetic studies. Later in the course, we take several field trips in which the students examine diagenetic features.

Kathy Benison

271

A Process for COTS Software Product Evaluation  

Microsoft Academic Search

The growing use of commercial products in large systems makes evaluation and selection of appropriate products an increasingly essential activity. However, many organizations struggle in their attempts to select an appropriate product for use in systems. As part of a cooperative effort, the Software Engineering Institute (SEI) and the National Research Council Canada (NRC) have defined a tailorable software product

Santiago Comella-dorda; John C. Dean; Edwin J. Morris; Patricia A. Oberndorf

2002-01-01

272

THE NEW PRODUCT DEVELOPMENT PROCESS IN AUSTRALIAN GROCERY ORGANISATIONS  

Microsoft Academic Search

The idea that new product development is vital to many organisations' business survival and growth is widely acknowledged. New products provide many business opportunities for organisations. The relationship between new product development and business strategy is critical, as corporate purpose and scope sets the guidelines for new product planning. This paper examines the new product development process in the Australian

Jerry SOLDATOS; Jurate HARDY

2007-01-01

273

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2001-01-15

274

QUAUTE DES PRODUITS — QUALITY OF PRODUCTS Processing ability of pork products  

E-print Network

QUAUTE DES PRODUITS — QUALITY OF PRODUCTS Processing ability of pork products B. JACQUET of national consumption as in terms of production of fresh, processed and cured products, canned meat in 1986. As regards the pork meat products, the distribution of imports and exports per category

Paris-Sud XI, Université de

275

Reduced product yield in chemical processes by second law effects  

Microsoft Academic Search

An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value

C. England; J. E. Funk

1980-01-01

276

Communication Improving silica fume cement by using silane  

E-print Network

furnaces as a by-product of the production of metallic silicon or ferrosilicon alloys. It is a powder an increasingly common admixture in cement-based materials [52±55]. Surface treatment of silica fume with sulfuric acid prior to incorporation in a cement matrix results in mortars exhibiting increases in tensile

Chung, Deborah D.L.

277

Experience with roller press systems at Southern Province Cement Company  

Microsoft Academic Search

The upgrade of the circuit #1 cement grinding system at the Southern Province Cement Company Bisha plant has proved to be a successful design of a clinker pre-grinding circuit. The simple layout has fulfilled expectations not only on the basis of production and product quality, but also on installed power and equipment cost, equipment selection, and operating and maintenance costs.

M. N. Sukkar; K. Happ; A. Shahid

2005-01-01

278

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

USGS Publications Warehouse

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.

Kelly, Thomas

1998-01-01

279

Atmospheric Processing Module for Mars Propellant Production  

NASA Technical Reports Server (NTRS)

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.

Muscatello, Anthony C.

2014-01-01

280

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

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.

Wong, H.S. [Concrete Durability Group, Imperial College London, SW7 2AZ (United Kingdom)], E-mail: hong.wong@imperial.ac.uk; Buenfeld, N.R. [Concrete Durability Group, Imperial College London, SW7 2AZ (United Kingdom)

2009-10-15

281

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

PubMed Central

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

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

2004-01-01

282

Soft X-ray Microscopy of Green Cements  

SciTech Connect

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.

Monteiro, P. J. M.; Mancio, M.; Chae, R.; Ha, J. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States); Kirchheim, A. P. [Department of Civil Engineering, Federal University of Rio Grande do Sul, Porto Alegre, RS, 90035-190 (Brazil); Fischer, P. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley CA, 94720 (United States); Tyliszczak, T. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley CA, 94720 (United States)

2011-09-09

283

CARBON DIOXIDE EMISSIONS FROM THE GLOBAL CEMENT INDUSTRY1  

Microsoft Academic Search

Abstract The cement industry contributes about 5% to global anthropogenic CO2 emissions, making the cement industry an important sector for CO2-emission mitigation strategies. CO2 is emitted from the calcination process of limestone, from combustion of fuels in the kiln, as well as from power generation. In this paper, we review the total CO2 emissions from cement making, including process and

Ernst Worrell; Lynn Price; Nathan Martin; Chris Hendriks; Leticia Ozawa Meida

2001-01-01

284

Holocene cemented beach deposits in Belize  

NASA Astrophysics Data System (ADS)

Two types of cemented beach deposits occur on reef islands off the coast of Belize. These are (1) intertidal beachrock that is dominantly cemented by marine aragonite and high-magnesium-calcite cements, and (2) supratidal cayrock that is cemented mainly by vadose low-magnesium-calcite cements. Besides differences in position relative to present sea level and resulting early diagenesic features, beachrock and cayrock can be distinguished on the basis of differences in composition, texture, geographical position, and age. Whereas the composition of beachrock is similar to that of the adjacent marginal reef sediments, cayrock is enriched in benthic foraminifera. Intertidal beachrock is moderately to well sorted and well cemented, while supratidal cayrock is very well sorted, poorly cemented and friable. Beachrock occurs preferentially on windward beaches of sand-shingle Gays on the middle and southern barrier reefs and on the isolated platforms Glovers and Lighthouse Reefs. Cayrock only occurs on larger mangrove-sand Gays of the isolated platforms Turneffe Islands, Lighthouse Reef, and the northern barrier reef. 14C-dating of ten whole-rock and mollusk shell samples produced calibrated dates between AD 345 and AD 1435 for beachrock and between BC 1085 and AD 1190 for cayrock. The large-scale distribution of beachrock in Belize supports the contention that physical processes such as water agitation rather than biological processes control beachrock formation and distribution. Only on windward sides of cays that are close to the reef crest, where large amounts of seawater flush the beaches, considerable amounts of cements can be precipitated to produce beachrock. Cayrock forms due to cementation in the vadose zone and is only preserved on larger, stable mangrove-sand cays.

Gischler, Eberhard; Lomando, Anthony J.

1997-06-01

285

Enhancing the mechanical properties of cement paste by growing in-situ fiber reinforcement during hydration  

NASA Astrophysics Data System (ADS)

Efforts to improve the mechanical properties of concrete by modifying the cement paste matrix have focused entirely on strength enhancement. But the intrinsic brittleness of the cement paste matrix limits the possible improvement in the mechanical properties of concrete, and in particular the toughness of the material. Increasing the toughness of the cement paste matrix could lead to a reduction in flaw sensitivity by delaying unstable crack propagation. Consequently, the resistance of the material to cracking due to drying shrinkage, thermal shrinkage, expansive deterioration processes, and applied loads could increase considerably. The goal of this study was to grow in-situ fiber reinforcement in cement paste, a technique never before applied to cement-based materials, to enhance the toughness of the material. Ettringite, an existing, fiber-like hydration product was selected as the fiber reinforcement. Ettringite met all the necessary criteria to act as reinforcement in cement paste: adequate distribution in the matrix; adjustable volume fraction, aspect ratio and size; high stiffness along the fiber length; and finally compatibility with existing hydration products. Alkali-free accelerators were selected as the admixtures used to grow the ettringite in the cement paste. X-ray diffraction and scanning electron microscopy experiments were performed to study the volume fraction, distribution, size, and morphology of the ettringite crystals in the cement paste matrix (both plain and accelerator-containing). Mechanical tests (compression, splitting tension, flexural, compact tension) were used to evaluate the effect of the accelerators on the strength and toughness of cement paste. Microindentations on the surface of the cement paste matrix were performed to study the morphology of the cracks and the toughening mechanisms taking place. Through the characterization tests we identified that while more ettringite forms with the addition of the alkali-free accelerators, some of that ettringite forms in highly-porous inclusions distributed throughout the matrix. The compact tension specimen results showed that the accelerated specimens had a higher toughness and ductility compared to the control specimens. The dominant toughening mechanism identified was constrained microcracking, with the ettringite inclusions contributing to microcracking.

Constantinides, Margarita

286

Uniqueness and the Multiple Fractal Character of Product Engineering Processes  

Microsoft Academic Search

\\u000a This metaphor, taken from an article about the Christian church, is also valid for the complex system of product engineering.\\u000a Every product engineering process is unique and individual. This is the first out of five hypotheses about product engineering\\u000a processes (Albers, 2010). In this paper we investigate where the differences between product engineering processes originate\\u000a from. We examine the integrated

A. Albers; A. Braun; S. Muschik

287

Bagasse-reinforced cement composites  

Microsoft Academic Search

Bagasse is abundantly available in many countries as a by-product from sugar mills and is being mostly used as fuel or disposed of by incineration. An attempt has been made to convert this byproduct into useful eco-friendly cement-bonded composites, which can be used for various internal and external applications in buildings. The investigations include optimization of parameters such as bagasse

L. K. Aggarwal

1995-01-01

288

Laboratory-produced high-volume fly ash blended cements: physical properties and compressive strength of mortars  

Microsoft Academic Search

This paper describes the production of laboratory-produced high-volume fly ash blended cements. The effect of grinding of the Portland cement clinker, fly ash, and gypsum with or without a superplasticizer on the physical properties of the cements, and the compressive strength of the mortars made with the resulting blended cements, is discussed. The use of ground fly ash compared with

N. Bouzoubaa; M. H. Zhang; A. Bilodeau; V. M. Malhotra

1998-01-01

289

Process management applications in biopharmaceutical drug production  

E-print Network

Genzyme's manufacturing and supply chain organization is responsible for the production and delivery of medically necessary medicines for patients with rare diseases around the world. Because of the nature of the products ...

Smith, Stephen E

2011-01-01

290

Nano-ChemoMechanical assessment of Rice Husk Ash cement by wavelength dispersive spectroscopy and nanoindentation  

E-print Network

Cement global production stands at 3 Giga tons making concrete the most consumed structural mateial worldwide. This massively produced material comes with a heavy environmental footprint rendering the cement industry ...

Abuhaikal, Muhannad (Muhannad A. R.)

2011-01-01

291

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2003-01-31

292

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

PubMed Central

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

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

2013-01-01

293

Diverse Applications of Pinch Technology Within the Process Industries  

E-print Network

the use of pinch technology in a wider range of industries including food, pulp and paper, cement brewing and dairy product processes. These processes have featured; batch and continuous operations; solids, liquids and gas processing; use... by Linnhoff March. The projects listed include examples from the food, paper, dairy, brewing, cement and speciality chemical industries, and the results illustrate features common to many advanced pinch technology application. Batch Processes Pinch...

Spriggs, H. D.; Ashton, G.

294

48 CFR 870.111-5 - Frozen processed food products.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Frozen processed food products. 870.111-5 Section 870.111-5 Federal...Controls 870.111-5 Frozen processed food products...paragraph (c)(1) of this section was not met (no seal... (d) Producers of frozen bakery products...

2010-10-01

295

48 CFR 870.111-5 - Frozen processed food products.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Frozen processed food products. 870.111-5 Section 870.111-5 Federal...Controls 870.111-5 Frozen processed food products...paragraph (c)(1) of this section was not met (no seal... (d) Producers of frozen bakery products...

2011-10-01

296

Modelling Product Innovation Processes, from Linear Logic to Circular Chaos  

Microsoft Academic Search

Product innovation is the focal point of the Delft Design School in the Netherlands. During its more than thirty years of existence different models of the product innovation process were and are used for education and for research. This paper will describe the development of these models. The first models tried to describe the product innovation process in a logical

Jan Buijs

2003-01-01

297

Optimal levels of process parameters for products with multiple characteristics  

Microsoft Academic Search

The purpose of off-line quality control is to design robust products using robust manufacturing processes before the actual manufacturing of the product. Most of the research work has focused on determining the optimal level settings of process parameters for products with a single quality characteristic. In this paper, we employ the loss function approach to determine the optimal level settings

E. A. ELSAYED; ARGON CHEN

1993-01-01

298

Low fluid leakoff cementing compositions and filtration control additive for cement  

SciTech Connect

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.

Forrest, G.T.

1993-07-20

299

From Sentence Production to Text Production: Investigating Fundamental Processes.  

ERIC Educational Resources Information Center

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…

Fayol, Michel

1991-01-01

300

Lunar cement and lunar concrete  

NASA Technical Reports Server (NTRS)

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.

Lin, T. D.

1991-01-01

301

Multi-Spectral Analysis Of Frying Processes For Meat Products  

E-print Network

Multi-Spectral Analysis Of Frying Processes For Meat Products Søren Blond Daugaard Kongens Lyngby properties in relation to the frying process of various meat products, using multi-spectral imaging process for meat using multi-spectral vision technology. The project examines the possibility of creating

302

Work Structuring to Achieve Integrated ProductProcess Design  

E-print Network

Work Structuring to Achieve Integrated Product­Process Design Cynthia C. Y. Tsao, A.M.ASCE1 ; Iris presents "work structuring," a term used to describe the effort of integrating product and process design throughout the project development process. To illustrate current work structuring practice, we describe

Tommelein, Iris D.

303

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

NASA Astrophysics Data System (ADS)

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, ?m-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.

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

2008-12-01

304

TerraSAR-X SAR products and processing algorithms  

Microsoft Academic Search

This paper describes SAR products and algorithms of the DLR Payload Ground Segment for the TerraSAR-X satellite. The unified design of the processor is capable to generate consistent products from all imaging modes. Characteristic features of processor and products are given as they are relevant for the user. Keywords-component; TerraSAR-X, SAR products, SAR processing.

M. Eineder; B. Schattler; H. Breit; T. Fritz; A. Roth

2005-01-01

305

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

SciTech Connect

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.

O`Neal, G.W.

1996-04-01

306

PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS  

SciTech Connect

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.

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

2006-02-23

307

Process for the production of phthalic anhydride  

SciTech Connect

A system for producing phthalic anhydride by the catalytic oxidation of nathphalene, wherein without creating a significant pressure drop in the system substantially aff of the catalyst particles are removed from the product stream before the product stream is sent to a battery of switch condensers for recovery of the phthalic anhydride.

Miserlis, C. D.

1984-03-06

308

Hydrogen in the Methanol Production Process  

ERIC Educational Resources Information Center

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…

Kralj, Anita Kovac; Glavic, Peter

2006-01-01

309

Fundamental concepts of product/technology/process informational integration for process modelling and process planning  

E-print Network

(logistics, recycling, etc...). It remains, in a global vision of the enterprise, many prospective fields dramatically decreased mainly due to product versatility and diversity. The main reason is an increasing demand and processes (from the concepts to the physical industrial objects and environments). The base of knowledge

Boyer, Edmond

310

Cement rotary kiln control: A supervised adaptive model predictive approach  

Microsoft Academic Search

Considering the need of an advanced process control in cement industry, this paper presents an adaptive model predictive algorithm to control a white cement rotary kiln. As any other burning process, the control scenario is to expect the controller to regulate the temperature and the period of baking a fixed quantity of raw material as desired, as well as to

Javaneh Ziatabari; Alireza Fatehi; Mohamad T. H. Beheshti

2008-01-01

311

Classification and recognition of detecting parameters for cement rotary kiln  

Microsoft Academic Search

In view of the complex hot-working process of cement rotary kiln, all relative factors to process are measured and classified as faulty condition and normal condition. Alarming faulty condition. the running patterns of system are built with an improved ART-2 cluster parsing algorithm under normal condition, carry on the correct recognition to the status of cement rotary kiln.

Yuan Zhugang; Li Yongliang; Yu Hongliang

2008-01-01

312

Calculation of the corporate carbon footprint of the cement industry by the application of MC3 methodology  

Microsoft Academic Search

Cement is one of the most widely used construction materials in the world. Its characteristics, physicochemical properties and manufacturing process have long been the object of study. However, at this moment in time, the production of this basic construction material still accounts for 5% of worldwide emissions of CO2 into the atmosphere. Thus, in this age of the ongoing battle

Juan Cagiao; Breixo Gómez; Juan Luis Doménech; Salvador Gutiérrez Mainar; Hortensia Gutiérrez Lanza

2011-01-01

313

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

PubMed

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

Iyengar, S R; Al-Tabbaa, Abir

2007-12-01

314

Multivariable decoupling Fuzzy-Smith predictive control of cement rotary kiln temperature system  

Microsoft Academic Search

Cement rotary kiln thermal process can be viewed as an uncertain and complex temperature system with multivariable, strong coupling and time delays. The performance of combustion process control system will directly affect the quality of cement clinker, so it is necessary to control the temperature of every part in the kiln strictly in order to ensure the quality of cement

Li Dong-Sheng; Fang Yi-Ming; Li Jian-Xiong; Deng Li-Guang

2010-01-01

315

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2002-01-23

316

Matrix control cementing slurry  

SciTech Connect

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.

Arpenter, R.B.

1986-02-11

317

SOA Production From Cloud Processing of Glycolaldehyde  

NASA Astrophysics Data System (ADS)

Recent studies suggest that aqueous cloud chemistry contributes to secondary organic aerosol (SOA) production. Gas phase primary precursors, such as ethene and isoprene, can oxidize in the interstitial spaces of clouds to form water-soluble species, including glycolaldehyde. These water-soluble products can partition into cloud droplets and undergo further oxidation (e.g., via hydroxyl radicals). If low-volatility products (e.g., oxalate) are formed, these products can remain in the particle phase following droplet evaporation, forming organic aerosol. Organic aerosol plays an important role in cloud microphysics, visibility, and human health, yet little is known about aqueous phase reaction pathways and products that contribute to SOA. The kinetics of aqueous phase glycolaldehyde oxidation were studied and products were identified. Hydroxyl radical was generated via continuous UV photolysis of hydrogen peroxide inside a glass photochemical vessel. The reaction of glycolaldehyde and hydroxyl radical was monitored in real-time via continuous electrospray ionization mass spectrometry (ESI-MS). Organic products (acids and aldehydes) formed and destroyed during the reaction were identified and quantified via negative and positive mode ionization. Based on ESI-MS data obtained, glycolaldehyde is oxidized via hydroxyl radical to glycolic acid, glyoxylic acid, and ultimately oxalic acid, as previously suggested. In addition, several unexpected higher molecular weight compounds were produced, and identification of these reaction products is currently underway. The results obtained from this study serve to validate and refine the aqueous SOA-producing pathway for glycolaldehyde in cloud chemistry models and can be used to increase the accuracy of SOA prediction in atmospheric air quality and climate models.

Perri, M. J.; Seitzinger, S. P.; Tan, Y.; Turpin, B. J.

2007-12-01

318

Mitigating the impact of a time-dependent production process  

E-print Network

Value-added processes that bear associated wait times occur frequently during production manufacturing and increase cycle time. Since the wait time is integral to the value created by the process, it can be difficult to ...

Dudnik, Sara A

2007-01-01

319

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...

320

Reduced product yield in chemical processes by second law effects  

NASA Technical Reports Server (NTRS)

An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value of a product. As a result, it is particularly convenient in analyzing fuel conversion plants and their potential for improvement. Relationships are also given for the effects of irreversibilities on requirements for process heat and for feedstocks.

England, C.; Funk, J. E.

1980-01-01

321

Processing maize flour and corn meal food products  

PubMed Central

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

Gwirtz, Jeffrey A; Garcia-Casal, Maria Nieves

2014-01-01

322

Technical Writing: Process and Product. Third Edition.  

ERIC Educational Resources Information Center

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…

Gerson, Sharon J.; Gerson, Steven M.

323

Current Composition: Beyond Process vs. Product.  

ERIC Educational Resources Information Center

Reviews the development of writing paradigms from Aristotle's emphasis on invention, to eighteenth-century emphasis on induction and style, to the recent process approach, and the current expressive and cognitive approaches to writing instruction. Notes problems left unresolved by process theory and recommends the socio-contextual approach which…

Farris, Christine R.

1987-01-01

324

The density of cement phases  

SciTech Connect

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.

Balonis, M. [Department of Chemistry, Meston Building, University of Aberdeen, Aberdeen, AB24 3UE, Scotland (United Kingdom)], E-mail: m.balonis@abdn.ac.uk; Glasser, F.P. [Department of Chemistry, Meston Building, University of Aberdeen, Aberdeen, AB24 3UE, Scotland (United Kingdom)

2009-09-15

325

The Design and Implementation of a Cement kiln Expert System  

Microsoft Academic Search

This paper describes a cement production expert system developed in the way of integrating CLIPS with VC++ and based on SIMENS PCS7.The configuration, principle, exploiting methods of the system and the extraction of features of cement rotary kiln are presented. The system can give online guiding operations and increase economic profits. The experiment result shows its high adaptability and the

Shaolin Wang; Fengbo Dong; DongFeng Yuan

2007-01-01

326

PORTUGUESE RICE HUSK ASH AS A PARTIAL CEMENT REPLACEMENT  

Microsoft Academic Search

This paper presents a study of Portuguese rice husk ash as a partial cement replacement, in different percentages. Portuguese rice husk is a by-product which may be incinerated industrially. Various tests were carried out to evaluate durability of concrete made with 10, 15 and 20% replacement of rice husk ash by weight of cement. Tests carried out and reported in

Joaquim Sampaio; J. Sousa Coutinho; M. N. Sampaio

327

Interface abrasion between rough surface femoral stems and PMMA cement results in extreme wear volumes-A retrieval study and failure analysis.  

PubMed

During the loosening cascade of cemented rough femoral stems, the destruction of the mantle and the production of cement and metal wear debris occur after the loss of constraint at the interface. Two-dimensional (2D) measurements (light microscopy based morphometry on fragments of mantles and vertical scanning interferometry of femoral stems) permitted mathematical 3D-extrapolations to estimate the wear volumes. Fragments of the cement mantles available lost volumes from 0.85 mm(3) to 494.10 mm(3) (median amount of bone cement wear?=?178,426 mg). The harder metal surfaces lost between 1.459 mm(3) and 5.688 mm(3) of material (the median amount of metal wear per surface?=?1.504 mg/100 mm(2) ). Compared to the loss of material due to the fretting of stems, the abrasion of metal, and cement in defective cement mantles produced wear volumes sufficiently high to induce osteolysis. Though the design of the femoral stem and the handling of bone cement do not represent contemporary design and clinical practice, respectively, an extremely high number of joint replacements still in daily use may be impacted by this study because of possible predicted failures. Once the processes of fragmentation, abrasion, and osteolysis have been realized, the time until revision surgery should not be unduly prolonged. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 229-241, 2015. PMID:24820132

Buchhorn, Gottfried Hans; Bersebach, Petra; Stauch, Tilo; Schultz, Wolfgang; Köster, Georg

2015-01-01

328

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

329

Phosphate based oil well cements  

Microsoft Academic Search

The main application of the cement in an oil well is to stabilize the steel casing in the borehole and protect it from corrosion. The cement is pumped through the borehole and is pushed upwards through the annulus between the casing and the formation. The cement will be exposed to temperature and pressure gradients of the borehole. Modified Portland cement

Ramkumar Natarajan

2005-01-01

330

Cement penetration after patella venting  

Microsoft Academic Search

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement–bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration.Ten paired cadaver patellae were allocated prior to resurfacing to be vented or

Christopher W. Jones; Li-On Lam; Adam Butler; David J. Wood; William R. Walsh

2009-01-01

331

Pharmaceutical tablet compaction : product and process design  

E-print Network

This thesis explores how tablet performance is affected by microstructure, and how microstructure can be controlled by selection of excipients and compaction parameters. A systematic strategy for formulation and process ...

Pore, Mridula

2009-01-01

332

New products introduction process at Sun Microsystems  

Microsoft Academic Search

Explains the importance of concurrent engineering and its impact on product development success. Several cases studies of how Sun Microsystems practices concurrent engineering are presented. Sun Microsystems Computer Corporation is the world's largest leading supplier of open client-server computing solutions. The headquarters is located in Mountain View, California and Sun Microsystems has manufacturing plants in Milpitas, California; Linlithgow, Scotland and

C. Natale

1994-01-01

333

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

PubMed

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

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

2014-08-15

334

The Interaction between Central and Peripheral Processes in Handwriting Production  

ERIC Educational Resources Information Center

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),…

Roux, Sebastien; McKeeff, Thomas J.; Grosjacques, Geraldine; Afonso, Olivia; Kandel, Sonia

2013-01-01

335

Product-Process Distinctions in ELT Curriculum Theory and Practice  

ERIC Educational Resources Information Center

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…

Wette, Rosemary

2011-01-01

336

"Key Moments" as Pedagogical Windows into the Video Production Process  

ERIC Educational Resources Information Center

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…

Halverson, Erica; Gibbons, Damiana

2010-01-01

337

The DCS of Waste Heat Power Generation of Cement Plant Based on Fuzzy Control  

Microsoft Academic Search

The heat source of waste heat power generation of cement plant is the waste heat gas of cement rotary kiln. Influenced by the impact of cement production, the control system is complex, so the existing control scheme cannot make the satisfactory effect. Based on a thorough analysis of the existing control scheme and the reference to manual operation experience of

Shaoyun Wang; Qingjin Meng; Jingjian Wu

2009-01-01

338

Temperature prediction and analysis based on BP and Elman neural network for cement rotary kiln  

Microsoft Academic Search

In order to reduce energy consumption and improve the stability of cement burning system production, it is necessary to conduct in-depth analysis of the cement burning system, control the operation state and law of the system. In view of the rotary kiln consumes most of the fuel, we establish the simulation model of the cement kiln used to find effective

Baosheng Yang; Xiushui Ma

2010-01-01

339

Energy auditing and recovery for dry type cement rotary kiln systems––A case study  

Microsoft Academic Search

Cement production has been one of the most energy intensive industries in the world. In order to produce clinker, rotary kilns are widely used in cement plants. This paper deals with the energy audit analysis of a dry type rotary kiln system working in a cement plant in Turkey. The kiln has a capacity of 600 ton-clinker per day. It

Tahsin Engin; Vedat Ari

2005-01-01

340

ULTRA-LIGHTWEIGHT CEMENT  

SciTech Connect

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.

Fred Sabins

2003-07-31

341

Timing of syntaxial cement  

SciTech Connect

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.

Perkins, R.D.

1985-02-01

342

Fingerprinting of South African ordinary Portland cements, cement blends and mortars for identification purposes — Discrimination with starplots and PCA  

Microsoft Academic Search

This investigation is an attempt to analyse some of the current commercial cements and cement blends in South Africa and mortars produced from them (1:3 mixtures of cementitious material with different sands) for a suite of minor and trace elements that will provide a unique fingerprint of the final product. It was found in both the case of the OPC

S. S. Potgieter-Vermaak; J. H. Potgieter; A. Worobiec; R. van Grieken; L. Marjanovic; S. Moeketsi

2007-01-01

343

Integrated coke, asphalt and jet fuel production process and apparatus  

DOEpatents

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.

Shang, Jer Y. (McLean, VA)

1991-01-01

344

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...

345

Optimal biodiesel production using bioethanol: Towards process integration.  

E-print Network

Optimal biodiesel production using bioethanol: Towards process integration. Kristen Severson is to simultaneously optimize and heat integrate the production of biodiesel using ethanol in terms of the reaction). Because current biorefineries are becoming petrochemical complexes where a number of different products

Grossmann, Ignacio E.

346

Cognitive pragmatics relations in product symbol accepted process  

Microsoft Academic Search

The purpose of this paper is to present systemic cognitive pragmatics relations between product symbol and user for product symbol innovation. According to the theories of cognitive pragmatics, the cognitive pragmatics theory in product design was established. Combining with elements of semiotics, the work presented in this paper analyzed cognitive process with `denotation-connotation-function¿ and cognitive methods with `analogical relationship, logic

Zhi-jun Wu; Cheng-ai Na; Zhao-hui Bao

2008-01-01

347

Product Binding Varies Dramatically between Processive and Nonprocessive Cellulase Enzymes  

SciTech Connect

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.

Bu, L.; Nimlos, M. R.; Shirts, M. R.; Stahlberg, J.; Himmel, M. E.; Crowley, M. F.; Beckham, G. T.

2012-07-13

348

Production process for advanced space satellite system cables/interconnects.  

SciTech Connect

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.

Mendoza, Luis A.

2007-12-01

349

Significance of biotechnological processes in food production  

E-print Network

Knowledge Based BioEconomy [KBBE] is based mainly on taking advantages of modern, innovative technologies, including genetic engineering and biotechnology. Genetically modified products and technologies used for their production [particularly in the case of agro-food industry] raise a lot of emotions among the public. Majority of people is not oriented that: • the competitiveness of the agri-food industry is the result of low-cost feed, • Polish (as well as UE) nutritional self-sufficiency is not higher than 50%. In this situation public opinion is a political and economical factor. Legislation friendly for innovation is a major enhancer for scientific and technical progress. The answer for the question “Are we ready for GMO? ” is critically important and will be discussed in this lecture. L12.2

Legislation A. D; Tomasz Twardowski; Ra Ma?yska; W?odzimierz Bednarski; Waldemar Rymowicz

350

Low-cost process for hydrogen production  

DOEpatents

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.

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

1993-01-01

351

Low-cost process for hydrogen production  

DOEpatents

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.

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

1993-03-30

352

Process improvement exploration: mapping multimedia production process to CMMI-DEV  

NASA Astrophysics Data System (ADS)

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.

Lim, ChienWin; Kamaruddin, Noraida; Daud, Nor Izyani; Zainal Osman, Zosipha

2013-03-01

353

Improvement of casing cementation of deep and ultradeep wells. Part 2: Oilfield cements and cement additives  

Microsoft Academic Search

Oilfield cements and cement additives were investigated in order to improve the casing cementation of deep and ultradeep wells. Characterization and evaluation of the main oil field cements commercially available were studied. The testing was carried out according to American Petroleum Institute API standards and nonstandardized test methods (dynamic modulus of elasticity, expansion\\/shrinkage), especially the rheology, thickening time and the

K. H. Arens; M. Akstinat

1982-01-01

354

Sweet sorghum processing for alcohol production  

SciTech Connect

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.

Schmulevich, I.; Coble, C.G.; Egg, R.P.

1983-12-01

355

Process for the production of hydrogen peroxide  

DOEpatents

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.

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

1997-01-01

356

Biohydrogen gas production from food processing and domestic wastewaters  

Microsoft Academic Search

The food processing industry produces highly concentrated, carbohydrate-rich wastewaters, but their potential for biological hydrogen production has not been extensively studied. Wastewaters were obtained from four different food-processing industries that had chemical oxygen demands of 9g\\/L (apple processing), 21g\\/L (potato processing), and 0.6 and 20g\\/L (confectioners A and B). Biogas produced from all four food processing wastewaters consistently contained 60%

Steven W. Van Ginkel; Sang-Eun Oh; Bruce E. Logan

2005-01-01

357

Product review: lucis image processing software.  

PubMed

Lucis is a software program that allows the manipulation of images through the process of selective contrast pattern emphasis. Using an image-processing algorithm called Differential Hysteresis Processing (DHP), Lucis extracts and highlights patterns based on variations in image intensity (luminance). The result is that details can be seen that would otherwise be hidden in deep shadow or excessive brightness. The software is contained on a single floppy disk, is easy to install on a PC, simple to use, and runs on Windows 95, Windows 98, and Windows NT operating systems. The cost is $8,500 for a license, but is estimated to save a great deal of money in photographic materials, time, and labor that would have otherwise been spent in the darkroom. Superb images are easily obtained from unstained (no lead or uranium) sections, and stored image files sent to laser printers are of publication quality. The software can be used not only for all types of microscopy, including color fluorescence light microscopy, biological and materials science electron microscopy (TEM and SEM), but will be beneficial in medicine, such as X-ray films (pending approval by the FDA), and in the arts. PMID:10206154

Johnson, J E

1999-04-01

358

A non-linear model of economic production processes  

NASA Astrophysics Data System (ADS)

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.

Ponzi, A.; Yasutomi, A.; Kaneko, K.

2003-06-01

359

Neutron scattering studies of hydrating cement pastes  

NASA Astrophysics Data System (ADS)

The progress of the hydration reactions of tricalcium silicate (C 3S) has been followed using quasielastic neutron scattering (QNS) at an energy resolution of 60 ?eV and a momentum transfer of q = 1 Å-1. The degree of reaction in the hydrating cement paste is inferred from the fraction of water that is chemically bound to the cement reaction products and the known stoichiometry of C 3S hydration. Three different water-to-cement ratios were studied in this experiment: W/C = 0.7, 0.5 and 0.3. The results of an Avrami-model analysis of the first 15 h of the reaction are consistent with three types of C 3S?H 2O reaction product morphology and growth mechanisms: (i) a plate-type product phase from either phase boundary growth with no nucleation; (ii) diffusion-limited growth with constant nucleation; or (iii) a needle-type product phase with phase boundary growth and constant nucleation. Analysis of the later-time diffusion-limited portion of the reaction provides apparent diffusion constants for the migration of water through the C 3S hydration products. These data indicate that the diffusion constants vary approximately exponentially over the range of water-to-cement values studied.

Berliner, R.; Popovici, M.; Herwig, K.; Jennings, H. M.; Thomas, J.

360

Neutron scattering studies of hydrating cement pastes  

NASA Astrophysics Data System (ADS)

The progress of the hydration reactions of tricalcium silicate (C3S) has been followed using quasielastic neutron scattering (QNS) at an energy resolution of 60 ?eV and a momentum transfer of q=1 Å-1. The degree of reaction in the hydrating cement paste is inferred from the fraction of water that is chemically bound to the cement reaction products and the known stoichiometry of C3S hydration. Three different water-to-cement ratios were studied in this experiment: W/C=0.7, 0.5 and 0.3. The results of an Avrami-model analysis of the first 15 h of the reaction are consistent with three types of C3S-H2O reaction product morphology and growth mechanisms: (i) a plate-type product phase from either phase boundary growth with no nucleation; (ii) diffusion-limited growth with constant nucleation; or (iii) a needle-type product phase with phase boundary growth and constant nucleation. Analysis of the later-time diffusion-limited portion of the reaction provides apparent diffusion constants for the migration of water through the C3S hydration products. These data indicate that the diffusion constants vary approximately exponentially over the range of water-to-cement values studied.

Berliner, R.; Popovici, M.; Herwig, K.; Jennings, H. M.; Thomas, J.

1998-04-01

361

Monitoring the ettringite formation in cement paste using low field T2-NMR  

NASA Astrophysics Data System (ADS)

In the present work, we study the transverse relaxation time evolution of water molecules confined inside cement paste during the hydration process. The cement paste under study was manufactured with different water-to-cement ratios and using two types of cement: gray cement (CEM I 52.5 R) having a high content of magnetic impurities and white cement (CEM I 52.5 N) with lower amount of magnetic impurities. The two cement types were chosen in order to better distinguish the surface contribution to the relaxation process. On this basis a relationship between porosity evolution, ettringite formation and the transverse relaxation time evolution was established. It was also observed that the increase in the water-to-cement ratio better reveals the ettringite formation.

Pop, Alexandra; Badea, Codruta; Ardelean, Ioan

2013-11-01

362

PRODUCTION OF SYNTHETIC NATURAL GAS FROM BIOMASS - PROCESS INTEGRATED DRYING  

Microsoft Academic Search

Opportunities for process integrated feedstock drying in connection with the production of synthetic natural gas (SNG) from wet biomass via indirect gasification are investigated in this study. Drying is a very energy-intensive process step - corresponding to about 10% of the dry fuel lower heating value for woody biomass. Process integrated drying offers opportunities for reducing the external energy supply

Stefan Heyne; Simon Harvey

363

A Modeling Framework for Product Development Process Considering its Characteristics  

Microsoft Academic Search

Product development (PD) processes are complex and unstructured compared to business or manufacturing processes, as they have iterative, evolutionary, uncertain, and cooperative features. In order to effectively manage and control a complex PD process, appropriate and logical descriptions are needed. This requires a modeling framework that can capture its characteristics. However, previous modeling methodologies are limited in terms of representing

Hong-Bae Jun; Hyo-Won Suh

2008-01-01

364

Tensile Behavior of Fabric Cement-Based Composites: Pultruded and Cast  

E-print Network

Tensile Behavior of Fabric Cement-Based Composites: Pultruded and Cast A. Peled1 and B. Mobasher2 Abstract: There is a growing interest in the use of fabrics as reinforcements for cement composites due processing methods, casting and pultrusion, on the tensile properties of fabric-cement composites. Four

Mobasher, Barzin

365

From Rocks to Cement. What We Make. Science and Technology Education in Philippine Society.  

ERIC Educational Resources Information 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…

Philippines Univ., Quezon City. Science Education Center.

366

Prediction of Cement Physical Properties by Virtual Testing D.P. Bentza  

E-print Network

Prediction of Cement Physical Properties by Virtual Testing by D.P. Bentza , C.J. Haeckerb , X Process Technology of Cement Manufacturing. Fifth International VDZ Congress. Proceedings. Düsseldorf Institute of Standards and Technology and is not subject to copyright. #12;PREDICTION OF CEMENT PHYSICAL

Bentz, Dale P.

367

Measurement of Particle Size Distribution in Portland Cement Powder: Analysis of ASTM Round Robin Studies  

Microsoft Academic Search

A distribution of particle sizes or particle size distribution (PSD) is a fundamental characteristic of cement powder. Accurate PSDs are required in computational efforts to model the hydration process and it is an important practical issue for the cement industry. Presently, the only available standard method for measuring the PSD of cement, namely ASTM C115, is limited in scope, with

Chiara F. Ferraris; Vincent A. Hackley; Ana Ivelisse Avilés

2004-01-01

368

Sandstone cementation and fluids in hydrocarbon basins R.S. Haszeldinea,*, C.I. Macaulaya  

E-print Network

Sandstone cementation and fluids in hydrocarbon basins R.S. Haszeldinea,*, C.I. Macaulaya , A there is an intermediate view. Processes governing sandstone cementation in the deep sub-surface are elusive, case have driven studies of sandstone cementation in the past ten years: Firstly, the economic motive

Haszeldine, Stuart

369

Mechano-chemical modification of cement with high volumes of blast furnace slag  

Microsoft Academic Search

The application of chemical admixtures significantly improves the performance of cement-based materials. Some admixtures can also be used to modify the cement grinding process and induce changes in the structure of cement minerals due to mechano-chemical activation. A reactive silica-based complex admixture was developed for the modification of cement grinding. This paper examines the effect of grinding on the strength

Konstantin Sobolev

2005-01-01

370

Process for production desulfurized of synthesis gas  

DOEpatents

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.

Wolfenbarger, James K. (Torrance, CA); Najjar, Mitri S. (Wappingers Falls, NY)

1993-01-01

371

Early-age heat evolution of clinker cements in relation to microstructure and composition: implications for temperature development in large concrete elements  

Microsoft Academic Search

This paper presents an assessment of the range and extent of variation of heat evolution of nominally similar cement clinkers from a range of cement production facilities in South Africa. Clinker samples were collected at nine cement plants and cements were prepared by grinding each clinker with a uniform quality of gypsum. X-ray fluorescence and optical microscope techniques were then

Y. Ballim; P. C. Graham

2004-01-01

372

A descriptive model of the consumer co-production process  

Microsoft Academic Search

Purpose  This article presents a model of consumer engagement in co-production.\\u000a \\u000a \\u000a \\u000a Method  A theoretical paper which develops a five-stage dynamic model of consumer involvement in co-production.\\u000a \\u000a \\u000a \\u000a Results and Conclusions  The article discusses the basic linkages between co-production and customization and presents co-production as a dynamic process\\u000a which is composed of five distinct stages. It also specifies five distinct phases of the production activity

Michael Etgar

2008-01-01

373

7 CFR 926.11 - Processed cranberries or cranberry products.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

374

7 CFR 926.11 - Processed cranberries or cranberry products.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

375

7 CFR 926.11 - Processed cranberries or cranberry products.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

376

7 CFR 926.11 - Processed cranberries or cranberry products.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

377

7 CFR 926.11 - Processed cranberries or cranberry products.  

Code of Federal Regulations, 2014 CFR

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

2014-01-01

378

GREENING STANDARDS FOR GREEN STRUCTURES: PROCESS AND PRODUCTS  

EPA Science Inventory

The goal of this project is to provide a mechanism that equips consumers with the means for encouraging the homebuilding industry—designers, homebuilders, retail suppliers—to use environmentally preferable products (ENP) and processes in the design and con...

379

STATE OF THE ART: SWINE WASTE PRODUCTION AND PRETREATMENT PROCESSES  

EPA Science Inventory

A review of waste generation and pretreatment processes was compiled, expanded, and interpreted for the swine production industry. Typical swine units based upon waste management techniques were detailed as concrete slab facilities, slotted floorpit units, and swine drylot or pas...

380

Recombinant protein production and insect cell culture and process  

NASA Technical Reports Server (NTRS)

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.

Spaulding, Glenn (inventor); Prewett, Tacey (inventor); Goodwin, Thomas (inventor); Francis, Karen (inventor); Andrews, Angela (inventor); Oconnor, Kim (inventor)

1993-01-01

381

Constraints Based Modeling for Innovative Product & Process Designs  

Microsoft Academic Search

An innovative, constraints based modeling (CBM) approach proved successful for product developments and process improvements.\\u000a The product developments involved specifying the chemical composition range for a set of chromium-free, high-performance consumable\\u000a electrodes intended for gas-metal arc welding (GMAW) of high-strength steels used in hull constructions while significantly\\u000a reducing energy costs. The process improvements involved selecting appropriate non-carcinogenic chemicals for a

K. Sampath

2007-01-01

382

Membrane catalysis in the dehydrogenation and hydrogen production processes  

NASA Astrophysics Data System (ADS)

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.

Basov, N. L.; Ermilova, M. M.; Orekhova, N. V.; Yaroslavtsev, Andrei B.

2013-04-01

383

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...

384

GRAPH-BASED PRODUCT AND PROCESS MANAGEMENT IN  

E-print Network

- ment, and monitoring. Resource management refers to both human and computer resources. In particular is concerned with products, processes, and resources: Product management deals with the documents created, it comprises the organization of human resources, the repre- sentation of computer resources

Westfechtel, Bernhard

385

Cranberry processing waste for solid state fungal inoculant production  

Microsoft Academic Search

Cranberry pomace is a primary by-product of the traditional cranberry juice processing industry and its disposal presents economic and environmental problems. Microbial conversion of cranberry pomace into various value-added products is a practical approach for solving such disposal problems. The present research was undertaken to test the growth of several agriculturally and industrially important fungi on cranberry pomace substrate through

Zuoxing Zheng; Kalidas Shetty

1998-01-01

386

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...

387

Vehicle and Heavy Equipment Integrated Product & Process Development (IPPD)  

E-print Network

Vehicle and Heavy Equipment Integrated Product & Process Development (IPPD) Technology Development City, IA 52242 Beckermann, C., and Fischer, G.W., "Vehicle and Heavy Equipment Integrated Product, 1993. #12;Abstract An overview is presented of the recently proposed Vehicle and Heavy Equipment

Beckermann, Christoph

388

Challenges in Capitalizing Knowledge in Innovative Product Design Process  

Microsoft Academic Search

Capitalizing on company's knowledge is increasingly being recognized in a private organizations environment since managing knowledge productivity is considered a source of competitive advantage. In this paper we present a generalization of GAMETH framework, that play an important role in identifying crucial knowledge used and created in innovative product design process. Thus, we have developed a method based on three

Inès SAAD; Michel GRUNDSTEIN

389

Standardization of Components, Products and Processes with Data Mining  

E-print Network

1 Standardization of Components, Products and Processes with Data Mining Bruno AGARD Département de - 1527, USA andrew-kusiak@uiowa.edu ABSTRACT Data mining offers tools for extracting knowledge from databases. This paper discusses applications of data mining in standardization of components, products

Kusiak, Andrew

390

PROCESSING OF FATS AND OILS INTO VALUE-ADDED PRODUCTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The modification of fats and oils and their co-products for added value is a major theme of lipid research. Biotechnological processes often are favored for their mild reaction conditions and low environmental impact; they sometimes are the only practical routes to desired products. Nevertheless, ...

391

Solid recovered fuels in the cement industry with special respect to hazardous waste.  

PubMed

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 CO?-intensive. But most CO? 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

Thomanetz, Erwin

2012-04-01

392

Foamed cement: A second generation. [Foamed cement slurries  

Microsoft Academic Search

Advanced technology in design and implementation of stable foamed cement systems now offers new solutions to critical oil-field cementing problems well beyond the original utility of lightweight slurries in reducing hydrostatic pressure across fracture-sensitive zones. Implications of new high-performance foamed cement capabilities are discussed for specialized applications such as thermal recovery, deep cementing in a narrow annular gap, lost-circulation control

Loeffler

1984-01-01

393

Top-quark processes at NLO in production and decay  

NASA Astrophysics Data System (ADS)

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 {{? }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.

Campbell, John M.; Ellis, R. Keith

2015-01-01

394

Instrumental neutron activation analysis for the elemental analysis of cement  

Microsoft Academic Search

Cement is widely used as a construction material in Libya. Production plants introduce certain contaminants to the environment.\\u000a The dust from such plants is carried away to neighbouring areas. This dust contains a substantial amount of contaminants depending\\u000a on the origin of clays used in the production. In this study, a survey of elemental concentration of clay and cement was

Y. S. Khrbish; I. O. Abugassa; N. Benfaid; A. A. Bashir

2007-01-01

395

The Analysis of Taupo Pumice as an Effective Partial Cement Replacement in Concrete.  

E-print Network

??Concrete is an integral material in modern infrastructural requirements worldwide. The production of Portland cement is however expensive, energy intensive, and results in globally significant… (more)

Mason, Blair Joseph

2012-01-01

396

Hydrogen production by biological processes: a survey of literature  

Microsoft Academic Search

Hydrogen is the fuel of the future mainly due to its high conversion efficiency, recyclability and nonpolluting nature. Biological hydrogen production processes are found to be more environment friendly and less energy intensive as compared to thermochemical and electrochemical processes. They are mostly controlled by either photosynthetic or fermentative organisms. Till today, more emphasis has been given on the former

Debabrata Das; T. Nejat Veziro?lu

2001-01-01

397

Image processing system performance prediction and product quality evaluation  

NASA Technical Reports Server (NTRS)

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.

Stein, E. K.; Hammill, H. B. (principal investigators)

1976-01-01

398

A hierarchical approach to simultaneous design of products and processes  

Microsoft Academic Search

Product and process design involve algorithmic and heuristic processing of symbolic and numeric data. Therefore, for such a design task, a hybrid approach that interweaves numerical and heuristic paradigms is warranted. The increasing rigor in modeling along with the necessary knowledge feedback results in a generalized system architecture that forms the basis of this paper. The approach is implemented using

Burak Ozyurt; Praveen Mogili; Brad Mierau; Sermin G. Sunol; Aydin K. Sunol

1996-01-01

399

Supporting medical device development: a standard product design process model  

Microsoft Academic Search

This article describes the complex nature of the medical device development (MDD) process and presents a product design process model to aid designers engaged in MDD. Basically, the model serves as a conceptual framework and provides a set of formalisms to define the development landscape for medical devices. Specifically, the model describes the phases of MDD and their relationships, including

Lourdes A. Medina; Gül E. Okudan Kremer; Richard A. Wysk

2012-01-01

400

Zein purification: the process, the product, market potential  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objectives of this article intend to give an overview of a zein purification, decolorization and deodorization process, methodologies to assess those properties and applications of the purified product. The process involves column filtration of commercial zein solutions through a combination of ...

401

U.S. Productivity and Electronic Business Processes in Manufacturing  

Microsoft Academic Search

Recent studies argue that the use of information technology is a significant source of U.S. productivity growth. Official U.S. data on this use have been scarce. New official data on the use of electronic business processes (business processes such as procurement, payroll, inventory, etc., conducted over computer networks) in the manufacturing sector of the United States were recently released. Preliminary

B. K. Atrostic; John Gates

402

Production of concentrated kiwifruit juice by integrated membrane process  

Microsoft Academic Search

The concentration of fruit juices is industrially performed in order to reduce storage, packaging, handling and shipping costs. This paper describes the research efforts to develop and optimise an integrated membrane process, on laboratory scale, for the production of concentrated kiwifruit juice as alternative to the traditional vacuum evaporation. Fresh depectinated kiwifruit juice was previously clarified by ultrafiltration (UF) process.

A. Cassano; B. Jiao; E. Drioli

2004-01-01

403

PAPER PRODUCTION AND PROCESSING - OCCUPATIONAL EXPOSURE AND ENVIRONMENTAL RELEASE STUDY  

EPA Science Inventory

This report presents an analysis of chemicals and processes used during the production and processing of paper and paper goods with emphasis on the workplace exposure and environmental release of chemicals from these operations. Reviews of chemical substances in this report are i...

404

Cement composition and method of cement casing in a well  

SciTech Connect

A novel cement composition for the preparation of a novel aqueous slurry useful in cementing casing in the borehole of a well comprising cement, a hydroxyethylcellulose ether or a mixture of a hydroxyethylcellulose ether and a hydroxypropylcellulose ether a polysaccharide produced as a result of microbial action and a dispersant.

Baker, W.S.; Harrison, J.J.

1984-07-31

405

Cement composition and method of cement casing in a well  

SciTech Connect

A novel cement composition for the preparation of a novel aqueous slurry useful in cementing casing in the borehole of a well comprising cement, a hydroxyethylcellulose ether having a critical viscosity or a mixture of a hydroxyethylcellulose ether having a critical viscosity and of a hydroxypropylcellulose ether having a critical viscosity and a dispersant.

Baker, W.S.; Harrison, J.J.

1984-07-31

406

Control of the dehydration process in production of intermediate-moisture meat products: a review.  

PubMed

IM meat products are produced by lowering the aw to 0.90 to 0.60. Such products are stable at ambient temperature and humidity and are produced in nearly every country in the world, especially in developing areas where refrigeration is limited or unavailable. Traditionally IM meats use low cost sources of energy for drying, such as sun drying, addition of salt, or fermentation. Products produced by different processes are of interest since they do not require refrigeration during distribution and storage. Many different IM meat products can be produced by utilizing modern processing equipment and methods. Production can be achieved in a relatively short period of time and their advantages during marketing and distribution can be utilized. Nevertheless, a better understanding of the principles involved in heat transfer and efficiency of production are still needed to increase efficiency of processing. A basic understanding of the influence of water vapor pressure and sorption phenomena on water activity can materially improve the efficiency of drying of IM meats. Predrying treatments, such as fermentation and humidity control, can also be taken advantage of during the dehydration process. Such information can lead to process optimization and reduction of energy costs during production of IM meats. The development of sound science-based methods to assure the production of high-quality and nutritious IM meats is needed. Finally, such products also must be free of pathogenic microorganisms to assure their success in production and marketing. PMID:8794551

Chang, S F; Huang, T C; Pearson, A M

1996-01-01

407

Ionic liquid-based green processes for energy production.  

PubMed

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

Zhang, Suojiang; Sun, Jian; Zhang, Xiaochun; Xin, Jiayu; Miao, Qingqing; Wang, Jianji

2014-11-21

408

Self-tuning process monitoring system for process-based product  

SciTech Connect

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.

Hillaire, R. [Sandia National Labs., Livermore, CA (United States); Loucks, C. [Sandia National Labs., Albuquerque, NM (United States)

1998-02-01

409

Image processing and products for the Magellan mission to Venus  

NASA Technical Reports Server (NTRS)

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.

Clark, Jerry; Alexander, Doug; Andres, Paul; Lewicki, Scott; Mcauley, Myche

1992-01-01

410

Fish Processed Production Planning Using Integer Stochastic Programming Model  

NASA Astrophysics Data System (ADS)

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.

Firmansyah, Mawengkang, Herman

2011-06-01

411

Development of fluidized bed cement sintering technology  

SciTech Connect

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.

Mukai, Katsuji [Sumitomo Cement Co., Ltd. (Japan)

1994-12-31

412

Analytical calculation of heavy quarkonia production processes in computer  

NASA Astrophysics Data System (ADS)

This report is devoted to the analytical calculation of heavy quarkonia production processes in modern experiments such as LHC, B-factories and superB-factories in computer. Theoretical description of heavy quarkonia is based on the factorization theorem. This theorem leads to special structure of the production amplitudes which can be used to develop computer algorithm which calculates these amplitudes automatically. This report is devoted to the description of this algorithm. As an example of its application we present the results of the calculation of double charmonia production in bottomonia decays and inclusive the ?cJ mesons production in pp-collisions.

Braguta, V. V.; Likhoded, A. K.; Luchinsky, A. V.; Poslavsky, S. V.

2014-06-01

413

Curing time effect on the fraction of {sup 137}Cs from cement-ion exchange resins-bentonite clay composition  

SciTech Connect

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)

Plecas, Ilija; Dimovic, Slavko [Vinca Institute of Nuclear Sciences, P.O.BOX 522, 11001 Belgrade (Serbia)

2007-07-01

414

The JSC Engineering Directorate Product Peer Review Process  

NASA Technical Reports Server (NTRS)

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.

Jenks, Kenneth C.

2009-01-01

415

Hydration Characteristics of Metakaolin Admixtured Cement using DTA, XRD and SEM Techniques  

NASA Astrophysics Data System (ADS)

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.

Govindarajan, D.; Gopalakrishnan, R.

2008-04-01

416

Recent advances in lactic acid production by microbial fermentation processes.  

PubMed

Fermentative production of optically pure lactic acid has roused interest among researchers in recent years due to its high potential for applications in a wide range of fields. More specifically, the sharp increase in manufacturing of biodegradable polylactic acid (PLA) materials, green alternatives to petroleum-derived plastics, has significantly increased the global interest in lactic acid production. However, higher production costs have hindered the large-scale application of PLA because of the high price of lactic acid. Therefore, reduction of lactic acid production cost through utilization of inexpensive substrates and improvement of lactic acid production and productivity has become an important goal. Various methods have been employed for enhanced lactic acid production, including several bioprocess techniques facilitated by wild-type and/or engineered microbes. In this review, we will discuss lactic acid producers with relation to their fermentation characteristics and metabolism. Inexpensive fermentative substrates, such as dairy products, food and agro-industrial wastes, glycerol, and algal biomass alternatives to costly pure sugars and food crops are introduced. The operational modes and fermentation methods that have been recently reported to improve lactic acid production in terms of concentrations, yields, and productivities are summarized and compared. High cell density fermentation through immobilization and cell-recycling techniques are also addressed. Finally, advances in recovery processes and concluding remarks on the future outlook of lactic acid production are presented. PMID:23624242

Abdel-Rahman, Mohamed Ali; Tashiro, Yukihiro; Sonomoto, Kenji

2013-11-01

417

Cement Mason's Curriculum. Instructional Units.  

ERIC Educational Resources Information Center

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…

Hendirx, Laborn J.; Patton, Bob

418

Communication Cement-based thermocouples  

E-print Network

Communication Cement-based thermocouples Sihai Wen, D.D.L. Chung* Composite Materials Research Received 31 May 2000; accepted 4 August 2000 Abstract A cement-based thermocouple in the form of a junction between dissimilar cement pastes and exhibiting thermocouple sensitivity 70 7 mV/°C is provided

Chung, Deborah D.L.

419

Cement-Lock for Decontaminating  

E-print Network

Cement-Lock® Technology for Decontaminating Dredged Estuarine Sediments Topical Report N O L O G Y I N S T I T U T E Cement-Lock Demo Plant Prepared by: Michael C. Mensinger GAS conducted as part of the overall program "Cement-Lock®1 Technology for Decontaminating Dredged Estuarine

Brookhaven National Laboratory

420

Research of magnesium phosphosilicate cement  

Microsoft Academic Search

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

Zhu Ding

2005-01-01

421

Magnesium-phosphate-glass cements with ceramic-type properties  

DOEpatents

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.

Sugama, T.; Kukacka, L.E.

1982-09-23

422

Magnesium phosphate glass cements with ceramic-type properties  

DOEpatents

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.

Sugama, Toshifumi (Mastic Beach, NY); Kukacka, Lawrence E. (Port Jefferson, NY)

1984-03-13

423

Magnesium phosphate glass cements with ceramic-type properties  

SciTech Connect

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.

Sugama, T.; Kukacka, L.E.

1984-03-13

424

Monosaccharide production in an acid sulfite process: kinetic modeling.  

PubMed

Spent sulfite liquor is a lignocellulosic waste obtained after the sulfite pulping process. It is mainly formed by sugars and lignosulfonates which are isolated from the pulp during the cooking process. The current work investigates the kinetic modeling of the sulfite process from a biorefinery point of view since monosaccharides present in the spent liquor can be used as a raw material in further biorefinery processes to produce other value-added products. Kinetic parameters of carbohydrate degradation have been determined following sugar and inhibitors from wood to spent liquor, using laboratory scale reactors and different temperatures, 130, 140 and 150 °C. Three types of reaction schemes were developed. Kinetic parameters were obtained for each one using first and n order reactions, using Aspen Custom Modeler. Results show that the best temperature to be used in the process is 130 °C, giving the maximum sugar conversion, 33.91 mol% and obtaining 13.81 mol% of decomposition products. PMID:25458268

Rueda, C; Fernández-Rodríguez, J; Ruiz, G; Llano, T; Coz, A

2015-02-13

425

Production of organic acids by electrodialysis/pervaporation process.  

SciTech Connect

Lactate esters produced from carbohydrates have potential markets as nontoxic replacements for halogenated and toxic solvents and as feedstocks for large-volume chemicals and polymers. Argonne National Laboratory has developed a novel process for the production of high-purity lactate esters from carbohydrates. The process uses advanced electrodialysis and pervaporation technologies to overcome major technical barriers in product separation; more specifically, the process involves cation elimination without the generation of salt waste and efficient esterification for final purification. This patented process requires little energy input, is highly efficient and selective, avoids the large volumes of salt waste produced by conventional processes, and significantly reduces manufacturing costs. The enabling membrane separation technologies make it technically and commercially feasible for lactate esters to penetrate the potential markets.

Tsai, S. P.; Datta, R.; Henry, M.; Halpern, Y.; Frank, J. R.; Energy Systems

1999-05-01

426

Physicochemical characterization of cement kiln dust for potential reuse in acidic wastewater treatment.  

PubMed

Cement kiln dust (CKD) is a fine-grained material produced during the manufacture of cement. Current reuse options are limited and the bulk of CKD not reused in the cement manufacturing process is sent to landfills or stored on-site. Due to the calcium oxide (CaO) content of CKD, it has the potential to be used as a replacement for lime in treating acidic wastewaters such as acid rock drainage (ARD). This paper outlines the results of an examination of the physical and chemical properties of CKD samples collected from six cement plants. The CKD samples were analyzed for major oxides using X-ray diffraction (XRD), available lime, specific surface area, particle size, and morphology using scanning electron microscope (SEM) and compared with a commercial quicklime product. Conductivity, pH, and calcium concentrations of slaked CKD and quicklime solutions were used as indicators of reactivity of the CKD. Slaking of two of the CKD samples with the highest free lime contents (e.g., 34 and 37% free CaO) gave elevated pH values statistically comparable to those of the commercial quicklime sample that was characterized as having 87% available CaO. Acid neutralization trials indicate that even CKD samples with low free lime contents could be effective at neutralizing acidic wastewaters. PMID:19744781

Mackie, A; Boilard, S; Walsh, M E; Lake, C B

2010-01-15

427

Product development using process monitoring and NDE data fusion  

NASA Astrophysics Data System (ADS)

Composite process/product development relies on both process monitoring information and nondestructive evaluation measurements for determining application suitability. In the past these activities have been performed and analyzed independently. Our present approach is to present the process monitoring and NDE data together in a data fusion workstation. This methodology leads to final product acceptance based on a combined process monitoring and NDE criteria. The data fusion work station combines process parameter and NDE data in a single workspace enabling all the data to be used in the acceptance/rejection decision process. An example application is the induction welding process, a unique joining method for assembling primary composite structure, that offers significant cost and weight advantages over traditional fasted structure. The determination of the required time, temperature and pressure conditions used in the process to achieve a complete weld is being aided by the use of ultrasonic inspection techniques. Full waveform ultrasonic inspection data is employed to evaluate the quality of spar cap to skin fit, an essential element of the welding process, and is processed to find a parameter that can be used for weld acceptance. Certification of the completed weld incorporates the data fusion methodology.

Peterson, Todd; Bossi, Richard H.

1998-03-01

428

Benzene distribution in product streams from in-tank processing  

SciTech Connect

Benzene is the major product of radiolytic decomposition of tetraphenylborate salts during in-tank salt decontamination. Its production rate has been measured at the Savannah River Laboratory (SR) and at the University of Florida under various conditions of importance to the in-tank process. Recent work has been concerned with the extent of decomposition for long storage periods, and the composition of the product streams from the process. The major results from this work are: the stored potassium tetraphenylborate precipitate will decompose at a rate of 7.3 {plus minus} 1.1% per year; the major products of the decomposition are benzene, phenol, biphenyl, and phenylboric acid; decomposition is directly proportional to the total dose and is unaffected by dose rate; the decomposition produces acidic compounds which will cause a decrease in the pH of the storage tank. 13 refs., 6 figs., 6 tabs.

Walker, D.D.

1987-01-15

429

For the last decades, cement technologies encountered a very rapid evolution following the will to always built quicker with more efficient materials. The additional young appearance of ecological trends pushed cement industries to an adaption and improve  

E-print Network

For the last decades, cement technologies encountered a very rapid evolution following pushed cement industries to an adaption and improvement of their production methods in order to mini of the cement with supplementary cementitious mate- rials (SCMs) being generally waste from other industries

Dalang, Robert C.

430

NGNP Process Heat Applications: Hydrogen Production Accomplishments for FY2010  

SciTech Connect

This report summarizes FY10 accomplishments of the Next Generation Nuclear Plant (NGNP) Engineering Process Heat Applications group in support of hydrogen production technology development. This organization is responsible for systems needed to transfer high temperature heat from a high temperature gas-cooled reactor (HTGR) reactor (being developed by the INL NGNP Project) to electric power generation and to potential industrial applications including the production of hydrogen.

Charles V Park

2011-01-01

431

Economics of Milk Products Processing Plants in Texas.  

E-print Network

BULLETIN 883 &@+; ' Economics of ~ilk'Pioducts " / @* !@ Processing Plants -i~*T&s Location of milk products manufacturing plants in Texas. by types of product. summer 1957. DECEMBER 1957 TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS.... DIRECTOR. COLLEGE STATION, TEXAS ' Summary The 12,800 Texas farmers selling milk during 1957 marketed an estimated 260 million gallons of milk havigg a farm value of 115 million dollars and a retail value of more than 230 million dollars. The average...

Stelly, Randall

1957-01-01

432

Search for polarization effects in the antiproton production process  

E-print Network

For the production of a polarized antiproton beam various methods have been suggested including the possibility that antiprotons may be produced polarized which will be checked experimentally. The polarization of antiprotons produced under typical conditions for antiproton beam preparation will be measured at the CERN/PS. If the production process creates some polarization a polarized antiproton beam could be prepared by a rather simple modification of the antiproton beam facility. The detection setup and the expected experimental conditions are described.

Grzonka, D; Ritman, J; Sefzick, T; Oelert, W; Diermaier, M; Widmann, E; Zmeskal, J; Glowacz, B; Moskal, P; Zielinski, M; Wolke, M; Nadel-Turonski, P; Carmignotto, M; Horn, T; Mkrtchyan, H; Asaturyan, A; Mkrtchyan, A; Tadevosyan, V; Zhamkochyan, S; Malbrunot-Ettenauer, S; Eyrich, W; Hauenstein, F; Zink, A

2015-01-01

433

Effect of mixing water magnetic activation cycle on cement stone structure  

NASA Astrophysics Data System (ADS)

The paper presents results of investigations of hydration processes and structure formation of the cement paste matrix mixed with water activated by magneto static field using water treatment cycle technology. It is shown that crystallization of phases occurs in the cement-water system at different rates, and phase redistribution in the structure of the cement paste matrix is described before and after magnetic activation of mixing water. Also, modeling of the cement-water system and calculations of amorphous and crystalline phases using the Rietveld refinement method before and after magnetic activation show that strength properties of the cement paste matrix depend not only on quantitative but also qualitative relationship between phases.

Kugaevskaya, S. A.; Abzaev, Yu A.; Safronov, V. N.; Sarkisov, Yu S.; Gorlenko, N. P.; Ermilova, T. A.

2015-01-01

434

A clinical retrospective evaluation of 2 orthodontic band cements.  

PubMed

This study aimed to compare the time to first failure of stainless steel orthodontic first permanent molar bands cemented with either a modified composite (Band-Lok, Reliance Orthodontic Products) or a conventional glass ionomer cement (AquaCem, De Trey Dentsply). The effect of patient sex, patient age at the start of treatment, the presenting malocclusion, treatment mechanics, and the operator proficiency on band survival was also assessed. Data for 219 bands cemented with Band-Lok in 108 patients and for 395 bands cemented with AquaCem in 183 patients were analyzed. For each case, a single molar band, either the band that was first to fail or the band that had the shortest follow-up time, was chosen for analysis. For each cement, whether headgear was used or not, there was no significant difference in time to first band failure (P = .398). Twenty-six percent of patients had at least one band failure with Band-Lok, and 30% of patients had at least one band failure with AquaCem, representing an 18% band failure rate for each cement. There was no significant difference in time to first band failure for either cement with respect to sex of the patient (P = .842), patient age at the start of treatment (P = .257), presenting malocclusion (P = .319), or operator proficiency (P = .062). The use of headgear, however, reduced significantly the time to first band failure irrespective of cement type (P = .0069). Headgear use was identified as a predictor of first permanent molar band survival. Clinical performance of bands cemented with either cement appears to be similar and was influenced significantly by the use of headgear. PMID:11771786

Millett, D T; Hallgren, A; McCluskey, L A; McAuley, F; Fornell, A C; Love, J; Christie, H

2001-12-01

435

Mechanics of aeolian processes: Soil erosion and dust production  

NASA Technical Reports Server (NTRS)

Aeolian (wind) processes occur as a result of atmosphere/land-surface system interactions. A thorough understanding of these processes and their physical/mechanical characterization on a global scale is essential to monitoring global change and, hence, is imperative to the fundamental goal of the Earth observing system (Eos) program. Soil erosion and dust production by wind are of consequence mainly in arid and semi arid regions which cover 36 percent of the Earth's land surface. Some recent models of dust production due to wind erosion of agricultural soils and the mechanics of wind erosion in deserts are reviewed and the difficulties of modeling the aeolian transport are discussed.

Mehrabadi, M. M.

1989-01-01

436

Satellite Imagery Production and Processing Using Apache Hadoop  

NASA Astrophysics Data System (ADS)

The United States Geological Survey's (USGS) Earth Resources Observation and Science (EROS) Center Land Science Research and Development (LSRD) project has devised a method to fulfill its processing needs for Essential Climate Variable (ECV) production from the Landsat archive using Apache Hadoop. Apache Hadoop is the distributed processing technology at the heart of many large-scale, processing solutions implemented at well-known companies such as Yahoo, Amazon, and Facebook. It is a proven framework and can be used to process petabytes of data on thousands of processors concurrently. It is a natural fit for producing satellite imagery and requires only a few simple modifications to serve the needs of science data processing. This presentation provides an invaluable learning opportunity and should be heard by anyone doing large scale image processing today. The session will cover a description of the problem space, evaluation of alternatives, feature set overview, configuration of Hadoop for satellite image processing, real-world performance results, tuning recommendations and finally challenges and ongoing activities. It will also present how the LSRD project built a 102 core processing cluster with no financial hardware investment and achieved ten times the initial daily throughput requirements with a full time staff of only one engineer. Satellite Imagery Production and Processing Using Apache Hadoop is presented by David V. Hill, Principal Software Architect for USGS LSRD.

Hill, D. V.; Werpy, J.

2011-12-01

437

Modelling cement grinding circuits  

Microsoft Academic Search

Modelling and simulation studies were carried out at 26 cement clinker grinding circuits including tube mills, air separators and high pressure grinding rolls in 8 plants. The results reported earlier have shown that tube mills can be modelled as several mills in series, and the internal partition in tube mills can be modelled as a screen which must retain coarse

H. Benzer; L. Ergun; A. J. Lynch; M. Oner; A. Gunlu; I. B. Celik; N. Aydogan

2001-01-01

438

Mechanisms of Carbon Nanotube Production by Laser Ablation Process  

NASA Technical Reports Server (NTRS)

We will present possible mechanisms for nanotube production by laser oven process. Spectral emission of excited species during laser ablation of a composite graphite target is compared with that of laser irradiated C60 vapor. The similarities in the transient and spectral data suggest that fullerenes are intermediate precursors for nanotube formation. The confinement of the ablation products by means of a 25-mm diameter tube placed upstream of the target seems to improve the production and purity of nanotubes. Repeated laser pulses vaporize the amorphous/graphitic carbon and possibly catalyst particles, and dissociate fullerenes yielding additional feedstock for SWNT growth.

Scott, Carl D.; Arepalli, Sivaram; Nikolaev, Pavel; Smalley, Richard E.; Nocholson, Leonard S. (Technical Monitor)

2000-01-01

439

Dry-ADU process for UO 2 production  

NASA Astrophysics Data System (ADS)

Scattered granular ammonium diuranate (ADU) products were prepared directly by reacting atomized liquid droplets of uranyl fluoride or uranyl nitrate with ammonia gas. After calcination in nitrogen and reduction with the steam-hydrogen gas, the ADU products were converted to UO 2 powders which were pelletized and then sintered for characterization. No waste liquid filtrate was generated in the process. The ADU product and UO 2 powder were easy-handling. Uranium dioxide powders with low fluorine content and good pelletizing and sintering properties were prepared.

Ching-Tsven, Huang

1992-12-01

440

A Review on Biomass Torrefaction Process and Product Properties  

SciTech Connect

Biomass Torrefaction is gaining attention as an important preprocessing step to improve the quality of biomass in terms of physical properties and chemical composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of approximately 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-280 C. Thus, the process can be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, which produces a final product that will have a lower mass but a higher heating value. The present review work looks into (a) torrefaction process and different products produced during the process and (b) solid torrefied material properties which include: (i) physical properties like moisture content, density, grindability, particle size distribution and particle surface area and pelletability; (ii) chemical properties like proximate and ultimate composition; and (iii) storage properties like off-gassing and spontaneous combustion.

Jaya Shankar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; J. Richard Hess; Richard D. Boardman

2011-08-01

441

UCN production by multiphonon processes in superfluid Helium under pressure  

E-print Network

Cold neutrons are converted to ultra-cold neutrons (UCN) by the excitation of a single phonon or multiphonons in superfluid helium. The dynamic scattering function S(q, omega) of the superfluid helium strongly depends on pressure, leading to a pressure- dependent differential UCN production rate. A phenomenological expression for the multiphonon part of the scattering function s(lambda) describing UCN production has been derived from inelastic neutron scattering data. When combined with the production rate from single phonon processes this allows us to calculate the UCN production for any incident neutron flux. For calculations of the UCN production from single phonon processes we propose to use the values for S*(SVP) = 0.118(8) and S*(20 bar) = 0.066(6). As an example we will calculate the expected UCN production rate at the cold neutron beam for fundamental physics PF1b at the Institut Laue Langevin. We conclude that UCN production in superfluid helium under pressure is not attractive.

P. Schmidt-Wellenburg; K. H. Andersen; O. Zimmer

2009-01-29

442

Process Integration of Bioethanol from Sugar Cane and Hydrogen Production  

NASA Astrophysics Data System (ADS)

In this study several alternatives for process integration of bioethanol from sugar cane and hydrogen production were evaluated. Bioethanol was produced above all in the fermentation of sweetened juice from sugar cane, stillage was removed. Stillage and bagasse are the process byproducts. The bioethanol steam reforming is an endothermic catalytic process when vaporized ethanol and steam are fed using a 1:6 molar ratio to reformer with a Ni-catalyst at atmospheric pressure and 350xC. Taking into account the processes properties mentioned above, it is possible to integrate the bioethanol production from sugar cane and its reforming by using byproducts like bagasse and stillage and to produce energy for steam reforming and bioethanol solution concentration by direct firing (for bagasse) or anaerobic digestion to get methane (for stillage).

Hernandez, L.; Kafarov, V.

443

Monitoring lignocellulosic bioethanol production processes using Raman spectroscopy.  

PubMed

Process control automation in the emerging biorefinery industry may be achieved by applying effective methods for monitoring compound concentrations during the production processes. This study examines the application of Raman spectroscopy with an excitation wavelength of 785nm and an immersion probe for in situ monitoring the progression of pretreatment, hydrolysis and fermentation processes in the production of lignocellulosic ethanol. Raman signals were attenuated by light scattering cells and lignocellulosic particulates, which the quantification method to some degree could correct for by using an internal standard in the spectra. Allowing particulates to settle by using a slow stirring speed further improved results, suggesting that Raman spectroscopy should be used in combination with continuous separation when used to monitor process mixtures with large amounts of particulates. The root mean square error of prediction (RMSE) of ethanol and glucose measured in real-time was determined to be 0.98g/L and 1.91g/L respectively. PMID:25255187

Iversen, Jens A; Ahring, Birgitte K

2014-11-01

444

Impact of Wellbore Cement Degradation on CO2 Storage Integrity  

NASA Astrophysics Data System (ADS)

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.

Kutchko, B.; Strazisar, B.; Lowry, G.; Dzombak, D.; Thaulow, N.

2007-12-01

445

Optimal biorefinery product allocation by combining process and economic modeling  

Microsoft Academic Search

The integrated biorefinery has the opportunity to provide a strong, self-dependent, sustainable alternative for the production of bulk and fine chemicals, e.g. polymers, fiber composites and pharmaceuticals as well as energy, liquid fuels and hydrogen. Although most of the fundamental processing steps involved in biorefining are well-known, there is a need for a methodology capable of evaluating the integrated processes

N. E. Sammons Jr; W. Yuana; M. R. Eden; B. Aksoy; H. T. Cullinan

2008-01-01

446

Production of thermoelectric materials by mechanical alloying extrusion process  

Microsoft Academic Search

The extrusion process offers one of the greatest prospects for the industrial production of Bi2Te3-based thermoelectric alloys. When coupled with mechanical alloying, this process promises substantial cost savings because of its ability to deliver net shape components, leading to a reduction in the so-called kerf losses and higher material yields. It is also well known that materials produced using one

J.-M. Simard; D. Vasilevskiy; F. Belanger; J. L'Ecuyer; S. Turenne

2001-01-01

447

An extended model of design process of lean production systems by means of process variables  

Microsoft Academic Search

In this paper, we present an axiomatic modeling of lean production system design, using process variables (PVs). So far, we had developed a model for conceptual design of lean production systems by means of FR–DP relationships, the key characteristics of axiomatic design (AD) methodology, appeared in the proceedings of Second International Conference of Axiomatic Design. Albeit the model in question

Mahmoud Houshmand; Bizhan Jamshidnezhad

2006-01-01

448

Novel pyrolysis-gas chromatography\\/mass spectrometric techniques for the characterization of chemical additives in portland cement and concrete  

Microsoft Academic Search

The application of pyrolysis gas chromatography mass spectrometry (py-GC\\/MS) has been improved for the determination of chemical additives that are either interground with cement clinker during the manufacture of Portland cement or admixed with a mixture of cement, sand, and stone, and water for the production of concrete. This technique has been found to be readily applicable for phenol-based cement

Ara A. Jeknavorian; E. F. Barry; J. J. Litzau

1998-01-01

449

Evaluating Building Systems Based on Production Process Management and Lean Construction Concepts  

E-print Network

Evaluating Building Systems Based on Production Process Management and Lean Construction Concepts Proceedings IGLC `98 EVALUATING BUILDING SYSTEMS BASED ON PRODUCTION PROCESS MANAGEMENT AND LEAN CONSTRUCTION construction technologies. KEY WORDS Construction technology; production processes; lean construction. 1 Civil

Tommelein, Iris D.

450

27 CFR 41.1 - Importation of tobacco products, cigarette papers and tubes, and processed tobacco.  

Code of Federal Regulations, 2010 CFR

...Importation of tobacco products, cigarette papers and tubes, and processed tobacco. ...IMPORTATION OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Scope...Importation of tobacco products, cigarette papers and tubes, and processed tobacco....

2010-04-01

451

27 CFR 40.1 - Manufacture of tobacco products, cigarette papers and tubes, and processed tobacco.  

Code of Federal Regulations, 2010 CFR

...Manufacture of tobacco products, cigarette papers and tubes, and processed tobacco. ...MANUFACTURE OF TOBACCO PRODUCTS, CIGARETTE PAPERS AND TUBES, AND PROCESSED TOBACCO Scope...Manufacture of tobacco products, cigarette papers and tubes, and processed...

2010-04-01

452

Characterization of various cement grinding aids and their impact on grindability and cement performance  

Microsoft Academic Search

The aim of the present research work was the evaluation of six commercial grinding additives, which were used for the production of Portland cement (ground in a ball mill at a laboratory stage). For this purpose, a reference sample was also produced without using any admixture. The characterization of the grinding aids (GA) was carried out by Fourier transform infra-red

M. Katsioti; P. E. Tsakiridis; P. Giannatos; Z. Tsibouki; J. Marinos

2009-01-01

453

76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan  

Federal Register 2010, 2011, 2012, 2013, 2014

...No. 731-TA-461 (Third Review)] Gray Portland Cement and Cement Clinker From Japan Determination On the basis of the...revocation of the antidumping duty order on gray Portland cement and cement clinker from Japan would be likely to...

2011-12-08

454

Fuel ethanol production from crop residues and processing byproducts  

Technology Transfer Automated Retrieval System (TEKTRAN)

In 2007, the production of fuel ethanol from corn starch reached 6.5 billion gallons in the U.S.A. Various crop residues such as corn stover, wheat straw, and barley straw, and crop processing byproducts such as corn fiber and rice hulls can serve as low-cost lignocellulosic feedstocks for conversi...

455

Discourse Processes and Products: Land Surveyors in Hong Kong  

ERIC Educational Resources Information Center

The study reported in this paper aims to provide a description of professional communication pertaining to land surveying project management in Hong Kong, achieved through a comprehensive analysis of both workplace discourse processes and products. The study, situated in Hong Kong, represents a collaborative effort between English and Land…

Cheng, Winnie; Mok, Esmond

2008-01-01

456

NATO/CCMS PILOT STUDY ON CLEAN PRODUCTS & PROCESSES  

EPA Science Inventory

Led by the United States, represented by the U.S. Environmental Protection Agency's (EPA's) National Risk Management Research Laboratory, the Pilot Study on Clean Products and Processes was instituted to create an international forum where current trends, developments, and expert...

457

Teaching Introductory Geology by a Paradigm, Process and Product Approach  

Microsoft Academic Search

Students in introductory geology courses can easily become lost in the minutiae of terms and seemingly random ideas and theories. One way to avoid this and provide a holistic picture of each major subject area in a beginning course is to introduce, at the start of each section, the ruling paradigm, the processes, and resultant products. By use of these

M. Reams

2008-01-01

458

Discourse processes and products: Land surveyors in Hong Kong  

Microsoft Academic Search

The study reported in this paper aims to provide a description of professional communication pertaining to land surveying project management in Hong Kong, achieved through a comprehensive analysis of both workplace discourse processes and products. The study, situated in Hong Kong, represents a collaborative effort between English and Land Surveying and Geo-Informatics departments in a university and a civil engineering

Winnie Cheng; Esmond Mok

2008-01-01

459

The product–process–organisation relationship in complex development projects  

Microsoft Academic Search

This paper provides a framework linking products to innovation processes in order to show how knowledge, technology and organisation are all interrelated. These interactions create specific innovation management problems for companies developing complex, systemic capital goods. Firms can reduce development schedules and costs by efficiently allocating resources to reduce uncertainty about the implications of different design options. The paper proposes

P. Nightingale

2000-01-01

460

Handwriting Evaluation for Developmental Dysgraphia: Process Versus Product  

ERIC Educational Resources Information Center

The act of writing presents difficulties for 10-30% of elementary school children. This study's objectives were to compare the abilities of digitizer-based evaluation of the handwriting process and conventional evaluation of the handwriting product to discriminate between children with proficient and dysgraphic handwriting. Copied and dictated…

Rosenblum, Sara; Weiss, Patrice L.; Parush, Shula

2004-01-01

461

An electrolytic process for magnesium and its alloys production  

SciTech Connect

The largest amount of magnesium is used for aluminum-magnesium alloy production. The second largest use is in desulfurization of steel. A magnesium {minus}10 weight percent (w/o) aluminum alloy can also be used in both the above processes. Pure magnesium metal is not of much use for structural purposes. However, a magnesium {minus}10 w/o aluminum alloy melt which is also suitable for structural applications, can be produced as a bottom layer in an electrolytic magnesium production cell using a potassium chloride-magnesium chloride electrolyte at {approximately} 750 C. In this situation, the magnesium production process and the cell can be similar to the aluminum production process and its cell. The magnesium-aluminum alloys can be produced by electrolysis at far less cost than these alloys produced from the respective metals. The process can also be used to produce other magnesium alloys for use in the auto industry at comparatively far less cost. The largest increase in the magnesium usage in the future is going to be only in the magnesium alloys sector.

Sharma, R. [General Motors Research and Development Center, Warren, MI (United States). Physical Chemistry Dept.

1996-10-01

462

Integrated process for the production of methanol and ammonia  

Microsoft Academic Search

Disclosed is an integrated process for the production of methanol and ammonia which comprises the steps of subjecting a gaseous hydrocarbon feed to primary reforming with steam to produce a methanol synthesis gas containing H2 and CO, synthesizing methanol from this methanol synthesis gas, subjecting the purge gas resulting from the methanol synthesis step to secondary reforming with steam and

K. Miyashita; S. Nozawa

1982-01-01

463

Language Production and Reception: A Processability Theory Study  

ERIC Educational Resources Information Center

Pienemann's Processability Theory (PT) predicts an order of emergence of morphosyntactic elements in second language (L2) production data. This research investigates whether the same order of emergence can be detected in L2 reception data, specifically, data from a timed audio grammaticality judgment task (GJT). The results from three related…

Spinner, Patti

2013-01-01

464

Aligning products with supply chain processes and strategy  

Microsoft Academic Search

Purpose – As supply chain management has become more strategic (rather than transactional) in nature the need for a more integrated perspective of how products, and processes should be aligned with strategic decisions to enhance competitive advantage has been amplified. The purpose of this paper is to provide a better understanding of how this alignment should be done. Design\\/methodology\\/approach –

Euthemia Stavrulaki; Mark Davis

2010-01-01

465

Processes for combined production of hydrogen and other chemical products without using fossil fuels  

NASA Astrophysics Data System (ADS)

The advantages and disadvantages of the combined production of hydrogen and other chemical products are discussed. Potential feedstocks in addition to water are examined. Aside from fossil fuels, the most attractive hydrogen-producing system is found to be that using sulfur compounds and water. This system permits substantial quantities of hydrogen to be produced together with various amounts of sulfuric acid, ammonium sulfate, or calcium sulfate. The way in which the output of the by-product can be reduced with the aid of new processes is described. It is noted that hydrogen produced by such processes could be much cheaper than hydrogen from water electrolysis.

Schuetz, G. H.

466

Quality control throughout the production process of infant food.  

PubMed

The manufacture of infant food is a highly complex process and needs an effective quality control beyond classical in-process parameters and a final microbiological analysis. To ensure a safe end -product, various tools, such as the Hazard Analysis Critical Control Points (HACCP), have been developed to facilitate the management of food safety. Every single infant formula ingredient must have an excellent quality and safety approach because even if an ingredient is used in very small quantities in a single product, serious consequences may arise if the quality and product safety are not taken seriously by the ingredient manufacturer. The purpose of this article was twofold: firstly, to briefly describe existing Quality Management Systems and, secondly, to highlight the consequences of non-quality. PMID:22699770

Hamrin, Pia; Hoeft, Birgit

2012-01-01

467

Cell culture process operations for recombinant protein production.  

PubMed

The market for protein therapeutics has grown significantly over the past two decades and the pace of development continues to increase. It is a challenge to the industry to maintain the desired quality attributes while accelerating delivery to patients, reducing the cost of goods, and providing production flexibility. Efficient manufacturing scale production of protein therapeutics is required to continue to meet the needs of the patients and stockholders. This chapter describes batch, fed-batch, and perfusion processes and their utilization in the production of monoclonal antibodies and other therapeutic proteins. In addition, we have provided detailed discussions of the ongoing challenges of lactate metabolism and the future prospects of process monitoring and control. PMID:24153406

Abu-Absi, Susan; Xu, Sen; Graham, Hugh; Dalal, Nimish; Boyer, Marcus; Dave, Kedar

2014-01-01

468

Mineral resource of the month: hydraulic cement  

USGS Publications Warehouse

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.

van Oss, Hendrik G.

2012-01-01

469

INNOVATIVE FRESH WATER PRODUCTION PROCESS FOR FOSSIL FUEL PLANTS  

SciTech Connect

An innovative Diffusion Driven Desalination (DDD) process was recently described where evaporation of mineralized water is driven by diffusion within a packed bed. The energy source to drive the process is derived from low pressure condensing steam within the main condenser of a steam power generating plant. Since waste heat is used to drive the process, the main cost of fresh water production is attributed to the energy cost of pumping air and water through the packed bed. This report describes the annual progress made in the development and analysis of a Diffusion Driven Desalination (DDD) system. A combined thermodynamic and dynamic analysis demonstrates that the DDD process can yield a fresh water production of 1.03 million gallon/day by utilizing waste heat from a 100 MW steam power plant based on a condensing steam pressure of only 3'' Hg. Throughout the past year, the main focus of the desalination process has been on the diffusion tower and direct contact condenser. Detailed heat and mass transfer analyses required to size and analyze these heat and mass transfer devices are described. An experimental DDD facility has been fabricated, and temperature and humidity data have been collected over a range of flow and thermal conditions. The analyses agree quite well with the current data and the information available in the literature. Direct contact condensers with and without packing have been investigated. It has been experimentally observed that the fresh water production rate is significantly enhanced when packing is added to the direct contact condensers.

James F. Klausner; Renwei Mei; Yi Li; Jessica Knight

2004-09-01

470

Investigation of glass-ionomer cements using differential scanning calorimetry.  

PubMed

Six commercial glass-ionomer cements commonly used for various dental applications have been investigated using differential scanning calorimetry (DSC). The heat-flow behaviour and heat capacity of the cements were measured during isothermal (at 37 degrees C) setting reactions. The DSC results show that all materials undergo an exothermic setting process, but with different enthalpies of reactions and different heat capacities; there are no remaining endo- or exothermic reactions after the setting of the cement. All materials examined were found to be effective thermal insulators. PMID:15348851

Khalil, S K; Atkins, E D

1998-09-01

471

Correlation-optical method for cement particle size definition  

NASA Astrophysics Data System (ADS)

Optical correlation technique of cement particle size distribution determining is described. It is based on transverse coherent function measuring using a polarization transverse shearing interferometer. It is shown that set of particles with random form can be substituted with set of spherical particles. This result was obtained by simulation of different particles sets with different forms and orientations. The proposed technique of data processing decreases dependence of the result on interferometer noise, emission source intensity fluctuations and difference of refractive index magnitudes of different cement particles. Described technique allows fast and reliable determining the size distribution function of cement particles.

Gorsky, Mykhaylo P.; Maksimyak, Peter P.; Maksimyak, Andrew P.

2014-09-01

472

Matching top-bottom processes in charged higgs production  

NASA Astrophysics Data System (ADS)

Top is a very important probe to test theories for the electroweak symmetry breaking such as two-Higgs doublet models. One process of great interest in theories with extended Higgs sectors is the associated production of top, bottom and charged Higgs, described by gb ? H -t (where the extra b is described by parton showering) and gg ? H -tb. To get a reliable description of this production when the extra b-quark is observed, these processes must be matched to remove double-counting, a problem similar to that in the single top processes pp ? tbW ± and ub ? dt. In this talk, we present our method for doing this matching at a fully differential level, and its implementation in the event generator Pythia. The implementation files can be downloaded from http://www.isv.uu.se/thep/MC/matchig/ .

Alwall, Johan

2006-01-01

473

Cement from magnesium substituted hydroxyapatite.  

PubMed

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

Lilley, K J; Gbureck, U; Knowles, J C; Farrar, D F; Barralet, J E

2005-05-01

474

Preliminary process engineering evaluation of ethanol production from vegetative crops  

NASA Astrophysics Data System (ADS)

Vegetative crops show good potential as feedstock for ethanol production via cellulose hydrolysis and yeast fermentation. The low levels of lignin encountered in young plant tissues show an inverse relationship with the high cellulose digestibility during hydrolysis with cellulose enzymes. Ensiled sorghum species and brown midrib mutants of sorghum exhibit high glucose yields after enzyme hydrolysis as well. Vegetative crop materials as candidate feedstocks for ethanol manufacture should continue to be studied. The species studied so far are high value cash crops and result in relatively high costs for the final ethanol product. Unconventional crops, such as pigweed, kochia, and Russian thistle, which can use water efficiently and grow on relatively arid land under conditions not ideal for food production, should be carefully evaluated with regard to their cultivation requirements, photosynthesis rates, and cellulose digestibility. Such crops should result in more favorable process economics for alcohol production.

Moreira, A. R.; Linden, J. C.; Smith, D. H.; Villet, R. H.

1982-12-01

475

The crystallization processes in the aluminum particles production technology  

NASA Astrophysics Data System (ADS)

The physical and mathematical model of the crystallization process of liquid aluminum particles in the spray-jet of the ejection-type atomizer was proposed. The results of mathematical modeling of two-phase flow in the spray-jet and the crystallization process of fluid particles are given. The influence of the particle size, of the flow rate and the stagnation temperature gas in the ranges of industrial technology implemented for the production of powders aluminum of brands ASD, on the crystallization characteristics were investigated. The approximations of the characteristics of the crystallization process depending on the size of the aluminum particles on the basis of two approaches to the mathematical description of the process of crystallization of aluminum particles were obtained. The results allow to optimize the process parameters of ejection-type atomizer to produce aluminum particles with given morphology.

Arkhipov, Vladimir; Bondarchuk, Sergey; Goldin, Victor; Zharova, Irina

2015-01-01

476

Comparison of rotary cement kiln identified models  

Microsoft Academic Search

Rotary cement kiln is the main part of a cement plant that clinker is produced in it. Clinker is the main ingredient of cement. Continual and prolonged operation of rotary cement kiln is vital in cement factories. However, prolonged operation of the kiln is not possible and periodic repairs of the refractory lining would become necessary, due to non-linear phenomena

G. Noshirvani; A. Fatehi; B. Araabi; M. Shirvani; M. Azizi

2009-01-01

477

Solvent degradation products in nuclear fuel processing solvents  

SciTech Connect

The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

Shook, H.E. Jr.

1988-06-01

478

The calcination process in a system for washing, calcinating, and converting treated municipal solid waste incinerator fly ash into raw material for the cement industry.  

PubMed

Calcination is the second step in a washing-calcination-conversion system in which treated municipal solid waste incinerator fly ash and bottom ash can be reused as raw material in the cement industry and can decompose or stabilize hazardous compounds, reduce residue amounts, and alter residue characteristics. In this research, only fly ash is discussed. Chloride reduction is important if treated fly ash is to be reused in cement; however, the relationship between washed fly ash properties and chloride reduction by calcination is not well understood. This study used washed residues of three types of fly ash-raw fly ash (RFA) from the boiler or economizer of an incineration system, fly ash collected in a bag filter injected with calcium hydroxide (Ca(OH)2) for acid removal (CaFA), and fly ash collected in a bag filter injected with sodium bicarbonate (NaHCO3) for acid removal (NaFA)-in calcination experiments with varying temperature (400-1100 degrees C) and atmosphere (100% nitrogen [N2] at 25 mL/min or 10% oxygen [O2] [90% N2] at fluxes of 25, 50, and 75 mL/min). From the perspective of chloride reduction, heating to 1000 degrees C with 1-hr heating time, 1-hr holding time, and an atmosphere of 10% O2/90% N2 was most suitable for calcination. Under these conditions, chloride levels were reduced by 91, 52, and 96% in washed residues of RFA, CaFA, and NaFA, respectively. Among the washed residues, the weight of the washed residue of NaFA decreased the most. PMID:21850828

Zhu, Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Morisawa, Shinsuke

2011-07-01

479