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Sample records for cementation process project

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

    CERN Document Server

    Dayley, L

    2000-01-01

    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...

  2. Quantitative modelling of the degradation processes of cement grout. Project CEMMOD

    Energy Technology Data Exchange (ETDEWEB)

    Grandia, Fidel; Galindez, Juan-Manuel; Arcos, David; Molinero, Jorge (Amphos21 Consulting S.L., Barcelona (Spain))

    2010-05-15

    Grout cement is planned to be used in the sealing of water-conducting fractures in the deep geological storage of spent nuclear fuel waste. The integrity of such cementitious materials should be ensured in a time framework of decades to a hundred of years as mimum. However, their durability must be quantified since grout degradation may jeopardize the stability of other components in the repository due to the potential release of hyperalkaline plumes. The model prediction of the cement alteration has been challenging in the last years mainly due to the difficulty to reproduce the progressive change in composition of the Calcium-Silicate-Hydrate (CSH) compounds as the alteration proceeds. In general, the data obtained from laboratory experiments show a rather similar dependence between the pH of pore water and the Ca-Si ratio of the CSH phases. The Ca-Si ratio decreases as the CSH is progressively replaced by Si-enriched phases. An elegant and reasonable approach is the use of solid solution models even keeping in mind that CSH phases are not crystalline solids but gels. An additional obstacle is the uncertainty in the initial composition of the grout to be considered in the calculations because only the recipe of low-pH clinker is commonly provided by the manufacturer. The hydration process leads to the formation of new phases and, importantly, creates porosity. A number of solid solution models have been reported in literature. Most of them assumed a strong non-ideal binary solid solution series to account for the observed changes in the Ca-Si ratios in CSH. However, it results very difficult to reproduce the degradation of the CSH in the whole Ca-Si range of compositions (commonly Ca/Si=0.5-2.5) by considering only two end-members and fixed nonideality parameters. Models with multiple non-ideal end-members with interaction parameters as a function of the solid composition can solve the problem but these can not be managed in the existing codes of reactive

  3. Quantitative modelling of the degradation processes of cement grout. Project CEMMOD

    Energy Technology Data Exchange (ETDEWEB)

    Grandia, Fidel; Galindez, Juan-Manuel; Arcos, David; Molinero, Jorge (Amphos21 Consulting S.L., Barcelona (Spain))

    2010-05-15

    Grout cement is planned to be used in the sealing of water-conducting fractures in the deep geological storage of spent nuclear fuel waste. The integrity of such cementitious materials should be ensured in a time framework of decades to a hundred of years as mimum. However, their durability must be quantified since grout degradation may jeopardize the stability of other components in the repository due to the potential release of hyperalkaline plumes. The model prediction of the cement alteration has been challenging in the last years mainly due to the difficulty to reproduce the progressive change in composition of the Calcium-Silicate-Hydrate (CSH) compounds as the alteration proceeds. In general, the data obtained from laboratory experiments show a rather similar dependence between the pH of pore water and the Ca-Si ratio of the CSH phases. The Ca-Si ratio decreases as the CSH is progressively replaced by Si-enriched phases. An elegant and reasonable approach is the use of solid solution models even keeping in mind that CSH phases are not crystalline solids but gels. An additional obstacle is the uncertainty in the initial composition of the grout to be considered in the calculations because only the recipe of low-pH clinker is commonly provided by the manufacturer. The hydration process leads to the formation of new phases and, importantly, creates porosity. A number of solid solution models have been reported in literature. Most of them assumed a strong non-ideal binary solid solution series to account for the observed changes in the Ca-Si ratios in CSH. However, it results very difficult to reproduce the degradation of the CSH in the whole Ca-Si range of compositions (commonly Ca/Si=0.5-2.5) by considering only two end-members and fixed nonideality parameters. Models with multiple non-ideal end-members with interaction parameters as a function of the solid composition can solve the problem but these can not be managed in the existing codes of reactive

  4. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  5. Hydration process in Portland cement blended with activated coal gangue

    Institute of Scientific and Technical Information of China (English)

    Xian-ping LIU; Pei-ming WANG; Min-ju DING

    2011-01-01

    This paper deals with the hydration of a blend of Portland cement and activated coal gangue in order to determine the relationship between the degree of hydration and compressive strength development.The hydration process was investigated by various means:isothermal calorimetry,thermal analysis,non-cvaporable water measurement,and X-ray diffraction analysis.The results show that the activated coal gangue is a pozzolanic material that contributes to the hydration of the cement blend.The pozzolanic reaction occurs over a period of between 7 and 90 d,consuming portlandite and forming both crystal hydrates and ill-crystallized calcium silicate hydrates.These hydrates are similar to those found in pure Portland cement.The results show that if activated coal gangue is substituted for cement at up to 30% (w/w),it does not significantly affect the final compressive strength of the blend.A long-term compressive strength improvement can in fact be achieved by using activated coal gangue as a supplementary cementing material.The relationship between compressive strength and degree of hydration for both pure Portland cement and blended cement can be described with the same equation.However,the parameters are different since blended cement produces fewer calcium silicate hydrates than pure Portland cement at the same degree of hydration.

  6. Innovative cement plug setting process reduces risk and lowers NPT

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, T.; Rogers, H.; Lloyd, S.; Quinton, C. [Halliburton Energy Services, Calgary, AB (Canada); Tetrault, N. [Apache Canada, Calgary, AB (Canada)

    2006-07-01

    With increased drilling in mature fields and unconventional reservoirs, Canadian operators are experiencing a higher rate of lost circulation events. When drilling into lower fracture-gradient zones, operators face the risk of drilling through shallower depleted zones. The unique challenges associated with setting cement plugs in such open hole wells were described. The best solution to address lost circulation events is a properly designed cement slurry where cement can be squeezed into the lost circulation zones to strengthen the wellbore when set. The cement plug is drilled through, leaving the residual cement setting inside the problem zones. Since cement plugs are used for a wide range of reasons, such as healing losses, abandonment, and directional drilling, it is important that a competent cement plug is placed the first time. This paper presented a newly developed tool and a special process designed to meet the challenges associated with setting cement plugs. It is based on a tubing-release tool (TRT) in which a sacrificial tubing is placed into the lost circulation zone to balance the cement plug. The sacrificial tubing is released from the drillstring and remains in the wellbore. The TRT has been used as a plug-setting aid for lost-circulation plugs; shallow-water shut-off; kick-off plug placement; and multizone plugs to abandon. An overview of the TRT features was presented. The tool and process has been used by more than 20 operating companies around the world to successfully place cement plugs downhole on the first attempt. The disconnect has been used successfully in more than 120 wells throughout North and South America, Europe, the Middle East, and Australia. It has proven to lower the risk and non-productive time associated with drilling in mature fields and unconventional reservoirs. 7 refs., 5 figs.

  7. Influence of relationship water/cement upon the processing of cements with pozzolana in standard mortar

    Directory of Open Access Journals (Sweden)

    Gener Rizo, M.

    2002-03-01

    Full Text Available The processing of standard mortar is completed following different methods in accordance with the country, but they exist two fundamental tendecies, the ISO and the ASTM. The cuban norm for mechanic-physic tests is based in ISO, and so they use a constant relationship water/cement in the processing of standard mortar a great problem concerning the cement users when they tested those mixed with puzzolanes, because they don't take care of the bigger water needs of those materials. In this work we present an study of the behaviour of Pozzolanic Portland cements (PP-250 elaborates with a fix and changeable relationship water/cement, obtained starting from the fluidity of the pure Portland cement. (P-350 The results obtained shows that the mechanical resistance decreased in cement mortars PP-250 realised with changeable relationship water/cement. So we recommend the adoption of an optional procedure to elaborate a quality mortar with pozzolana cements.

    La elaboración del mortero normalizado se realiza internacionalmente por diferentes métodos, pero existen dos tendencias fundamentales, la enunciada por ISO y por ASTM. La norma cubana de ensayos físico-mecánicos de cemento se basa en la norma ISO, por lo que para la elaboración del mortero normalizado se utiliza una relación agua/cemento constante. Esto ha provocado discrepancias con los usuarios del cemento, especialmente cuando se ensayan los cementos que contienen puzolanas, ya que se plantea que no se tiene en cuenta la mayor demanda de agua de estos materiales. En el presente trabajo se presenta un estudio del comportamiento de cementos Portland Puzolánicos (PP-250 elaborados con una relación agua/ cemento fija y variable, lograda a partir de la fluidez de la pasta de cemento Portland puro (P-350. Los resultados obtenidos indican que se producen disminuciones en la resistencia mecánica en los morteros de cemento PP-250 elaborados con agua/ cemento variable y recomienda la

  8. Maximizing the Sustainability of Cement Utilization in Building Projects through the Use of Greener Materials

    Directory of Open Access Journals (Sweden)

    Mark Bediako

    2016-01-01

    Full Text Available Greener technologies and sustainable developments are currently among the main tools used by many industries in shaping the world for a better future. The construction industry that is known to have numerous negative impact on sustainability is now wide awake on sustainable measures which can aid in reducing its negative impact. In this work, green cement was produced from pyroprocessed clay (PC at 800°C and mixed together with Portland cement. This paper presents both laboratory tests and some field applications of green cement application. Laboratory tests performed included setting times, compressive strength, and shrinkage. Field applications of the green cement are shown. Results from the work showed that well-proportioned greener cement gained strengths between 11% and 30% more than Portland cement at standard curing period of 3, 7, 14, and 28 days. However, in real statistical terms, there was no difference between Portland cement and green cement strength performance. Shrinkage from both total and autogenous tests also showed insignificant differences between the two cements. The study recommends the use of green cements with pozzolanic origin than only Portland cement as a way to maximize sustainability in building projects.

  9. Early Implementation of Large Scale Carbon Dioxide Removal Projects through the Cement Industry

    Science.gov (United States)

    Zeman, F. S.

    2014-12-01

    The development of large-scale carbon dioxide reduction projects requires high purity CO2and a reactive cation source. A project seeking to provide both of these requirements will likely face cost barriers with current carbon prices. The cement industry is a suitable early implementation site for such projects by virtue of the properties of its exhaust gases and those of waste concrete. Cement plants are the second largest source of industrial CO2 emissions, globally. It is also the second largest commodity after water, has no ready substitute and is literally the foundation of society. Finally, half of the CO2 emissions originate from process reactions rather than fossil fuel combustion resulting in higher flue gas CO2concentrations. These properties, with the co-benefits of oxygen combustion, create a favorable environment for spatially suitable projects. Oxygen combustion involves substituting produced oxygen for air in a combustion reaction. The absence of gaseous N2 necessitates the recirculation of exhaust gases to maintain kiln temperatures, which increase the CO2 concentrations from 28% to 80% or more. Gas exit temperatures are also elevated (>300oC) and can reach higher temperatures if the multi stage pre-heater towers, that recover heat, are re-designed in light of FGR. A ready source of cations can be found in waste concrete, a by-product of construction and demolition activities. These wastes can be processed to remove cations and then reacted with atmospheric CO2 to produce carbonate minerals. While not carbon negative, they represent a demonstration opportunity for binding atmospheric CO2while producing a saleable product (precipitated calcium carbonate). This paper will present experimental results on PCC production from waste concrete along with modeling results for oxygen combustion at cement facilities. The results will be presented with a view to mineral sequestration process design and implementation.

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

    Science.gov (United States)

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

    2008-04-01

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

  11. Effect of Microwave Processing on Aluminate Cement Clinkering

    Institute of Scientific and Technical Information of China (English)

    DONG Jianmiao; LONG Shizong

    2005-01-01

    When raw materials were preheated to 1000-1300 ℃ by electricity and microwave was inputted for 1 min 5 s-4 mins, then alunminate clinkers were obtained. The f-CaO contents,XRD patterns and lithofacies analysis show that the microwave processing accelerates the clinkering reaction,and Fe2O3 is contributed to the aluminate cement clinkering. The appearance of liquid phase in process of microwave heating increases the microwave absorbability of materials greatly.

  12. Based on the Analytic Hierarchy Process of Cement Production Projects Overseas Staff Safety Quality Assessment%基于层次分析法的海外水泥生产项目员工安全素质评估

    Institute of Scientific and Technical Information of China (English)

    龚腾; 孙祺

    2013-01-01

    Improve the index selection of the safety quality evaluation of the staff for overseas cement production projects is a complicated multi-objective selection problem,this paper uses analytic hierarchy process(AHP)to study the influence factors of overseas staff safety quality,overseas staff safety quality evaluation system is established. Select 7 overseas staff safety quality evaluation system of the main indicators,as a rule layer,and under which set up the index of 34 points,better improve the employee's safety quality evaluation system. After analysis to calculate the weight of each evaluation index,improved priorities of overseas staff safety quality index selection,and improvement measures are put forward.%改进海外水泥生产项目员工安全素质评估指标的选取是一个复杂的多目标选择问题,本文运用层次分析法研究了海外员工安全素质的影响因素,建立了海外员工安全素质评估体系。选取7个海外员工安全素质评估系统的主要指标,作为准则层,并在其下设置了34个分指标,更好地完善了海外员工安全素质的评估体系。分析计算出各个评估指标的权值后,得到改进海外员工安全素质指标选取的优先次序,并提出了改进措施。

  13. Modeling and Optimization of Cement Raw Materials Blending Process

    Directory of Open Access Journals (Sweden)

    Xianhong Li

    2012-01-01

    Full Text Available This paper focuses on modelling and solving the ingredient ratio optimization problem in cement raw material blending process. A general nonlinear time-varying (G-NLTV model is established for cement raw material blending process via considering chemical composition, feed flow fluctuation, and various craft and production constraints. Different objective functions are presented to acquire optimal ingredient ratios under various production requirements. The ingredient ratio optimization problem is transformed into discrete-time single objective or multiple objectives rolling nonlinear constraint optimization problem. A framework of grid interior point method is presented to solve the rolling nonlinear constraint optimization problem. Based on MATLAB-GUI platform, the corresponding ingredient ratio software is devised to obtain optimal ingredient ratio. Finally, several numerical examples are presented to study and solve ingredient ratio optimization problems.

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

    Science.gov (United States)

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

    2016-01-25

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

  15. NEURO-FUZZY MODELLING OF BLENDING PROCESS IN CEMENT PLANT

    Directory of Open Access Journals (Sweden)

    Dauda Olarotimi Araromi

    2015-11-01

    Full Text Available The profitability of a cement plant depends largely on the efficient operation of the blending stage, therefore, there is a need to control the process at the blending stage in order to maintain the chemical composition of the raw mix near or at the desired value with minimum variance despite variation in the raw material composition. In this work, neuro-fuzzy model is developed for a dynamic behaviour of the system to predict the total carbonate content in the raw mix at different clay feed rates. The data used for parameter estimation and model validation was obtained from one of the cement plants in Nigeria. The data was pre-processed to remove outliers and filtered using smoothening technique in order to reveal its dynamic nature. Autoregressive exogenous (ARX model was developed for comparison purpose. ARX model gave high root mean square error (RMSE of 5.408 and 4.0199 for training and validation respectively. Poor fit resulting from ARX model is an indication of nonlinear nature of the process. However, both visual and statistical analyses on neuro-fuzzy (ANFIS model gave a far better result. RMSE of training and validation are 0.28167 and 0.7436 respectively, and the sum of square error (SSE and R-square are 39.6692 and 0.9969 respectively. All these are an indication of good performance of ANFIS model. This model can be used for control design of the process.

  16. Carbon dioxide capture from a cement manufacturing process

    Science.gov (United States)

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

    2011-07-12

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

  17. IT Project Prioritization Process

    DEFF Research Database (Denmark)

    Shollo, Arisa; Constantiou, Ioanna

    2013-01-01

    In most of the large companies IT project prioritization process is designed based on principles of evidencebased management. We investigate a case of IT project prioritization in a financial institution, and in particular, how managers practice evidence-based management during this process. We use...... a rich dataset built from a longitudinal study of the prioritization process for the IT projects. Our findings indicate that managers reach a decision not only by using evidence but from the interplay between the evidence and the judgment devices that managers employ. The interplay between evidence...... and judgment devices is manifested in three ways: supplementing, substituting, and interpreting evidence. We show that while evidence does not fully determine the decision, it plays a central role in discussions, reflections, and negotiations during the IT prioritization process....

  18. Review on Sintering Process of WC-Co Cemented Carbide in Metal Injection Molding Technology

    Science.gov (United States)

    Prathabrao, M.; Amin, Sri Yulis M.; Ibrahim, M. H. I.

    2017-01-01

    The objective of this paper is to give an overview on sintering process of WC-Co cemented carbides in metal injection molding technology. Metal injection molding is an advanced and promising technology in producing cemented nanostructured carbides. Cemented tungsten carbide (WC-Co) hard metal is known for its high hardness and wear resistance in various applications. Moreover, areas include fine grained materials, alternative binders, and alternative sintering techniques has been discussed in this paper.

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

    Science.gov (United States)

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

    2015-01-01

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

  20. Sustainability of cement kiln co-processing of wastes in India: a pilot study.

    Science.gov (United States)

    Baidya, Rahul; Ghosh, Sadhan Kumar; Parlikar, Ulhas V

    2017-02-28

    Co-processing in cement kiln achieves effective utilization of the material and energy value present in the wastes, thereby conserving the natural resources by reducing the use of virgin material. In India, a number of multifolded initiatives have been taken that take into account the potential and volume of waste generation. This paper studies the factors which might influence the sustainability of co-processing of waste in cement kilns as a business model, considering the issues and challenges in the supply chain framework in India in view of the four canonical pillars of sustainability. A pilot study on co-processing was carried out in one of the cement plant in India to evaluate the environmental performance, economical performance, operational performance and social performance. The findings will help India and other developing countries to introduce effective supply chain management for co-processing while addressing the issues and challenges during co-processing of different waste streams in the cement kilns.

  1. Effect of process variables on the preparation of artificial bone cements

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: pinto@peq.coppe.ufrj.br, E-mail: jjunior@peq.coppe.ufrj.br, E-mail: melo@peq.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Macromoleculas; Nele, M., E-mail: nele@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2013-10-15

    The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components. (author)

  2. Development of Pack Cementation Aluminizing Process on Inner Surface of 316L Stainless Steel Tube

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In order to form the FeAl coatings on the inner surface of the 316L stainless steel tube,the pack cementation aluminizing process is introduced in this paper. The outside diameter,wall thickness and

  3. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

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

    Science.gov (United States)

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

    2014-02-18

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

  5. Cement transport properties for wells in the phase 1A area of the Weyburn CO{sub 2} project

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, F.J.; Chalaturnyk, R. [Alberta Univ., Edmonton, AB (Canada)

    2005-07-01

    Geological storage of carbon dioxide (CO{sub 2}) is emerging as a viable way of reducing greenhouse gas emissions without severely changing the use of fossil fuels for power generation. However, the issue of possible leakage through existing wells must be addressed. One of the objectives of the International Energy Agency's (IEA) Weyburn CO2 Monitoring and Storage Project is to determine the long-term failure mechanisms of seals in and around wellbores penetrating the host aquifer. CO{sub 2} plumes can migrate updip from an injection well until it encounters a vertical pathway. This migration may occur very rapidly, in the order of years to tens of years. It is likely that over several hundred years, the main leakage mechanisms will change and chemical degradation of cement will likely play a major role. This paper addressed the computational options for assessing the potential range of cement transport properties needed for a long-term performance assessment of CO{sub 2} storage within the Weyburn system. With time, cement degrades in the form of cracking, and chemical alteration, depending on sealing quality, subsurface environment, and many other factors. The major processes of carbonation, sulfate attack and pH of the pore solution were discussed in terms of their influence on cement transport properties. It was emphasized that safe subsurface storage of CO{sub 2} can be improved with an increased understanding of how the transport properties of a well change under chemical attack, with a focus on hydraulic integrity over the short term (tens of years after shutting down the injection wells). It was concluded that the performance of the cement will depend on its resistance to attack by the CO{sub 2} stored in the reservoir and to the different aggressive ions found in the brine aquifers that are part of the reservoir system. It was estimated that the service life of cement, in regions exposed to moving groundwater within high permeability strata, ranges

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

    Science.gov (United States)

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

    2009-06-15

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

  7. A comprehensive model to describe radiolytic processes in cement medium

    DEFF Research Database (Denmark)

    Bouniol, P.; Bjergbakke, Erling

    2008-01-01

    Basic mechanisms controlling the radiolysis in cementitious matrices are reviewed in the specific context of the gamma irradiation, in closed system without upper vapour space, at 25 degrees C, with a pore solution representative of a Portland cement paste. A general survey of data corresponding...

  8. Cement Manufacturing Plant Guidelines: An Approach to Reconciling the Financing of Cement with Climate Change Objectives

    OpenAIRE

    2010-01-01

    Cement manufacturing is an energy-intensive process, requiring high fuel consumption to operate cement kilns, which in turn generates carbon dioxide (CO2). These Guidelines aim to provide clear and quantitative Minimum Climate Change Performance Criteria necessary for IDB to support projects, as well as guidance on assessing and reducing the greenhouse gas (GHG) emissions of projects. The purpose of the Cement Manufacturing Plant guidelines is to set forth an approach for the financing of new...

  9. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2002-07-30

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

  10. INVESTIGATION OF CEMENT CONCRETE CONGLOMERATE SOLIDIFICATION PROCESS BY IMPEDANCE SPECTROSCOPY METHOD

    Directory of Open Access Journals (Sweden)

    S. N. Bandarenka

    2015-01-01

    Full Text Available One of the most prospective directions in preservation  and increase of service live of  road pavements is a construction of  automobile roads with cement concrete surface. Modern tendencies for provision of road construction quality presuppose a necessity to control processes of solidification and subsequent destruction of the material while forming and using cement concrete conglomerate being considered as a basic element of the road surface.  Multiyear practical experience of  automobile road operation using cement concrete pavements reveals an importance for monitoring  such processes as formation and destruction of cement concrete materials. An impedance spectroscopy method has been tried out and proposed as a tool for solution of the given problem.Experimental samples of cement concrete have been prepared for execution of tests, graded silica sand and granite chippings with particle size from 0.63 to 2.5 mm have been used as a fine aggregate in the samples. Dependencies of resistance (impedance on AC-current frequency  have been studied for samples of various nature and granulometric composition. The Gamry  G300 potentiostat has been used for measurement of complex impedance value. A spectrum analysis and calculation of equivalent circuit parameters calculation have been carried out while using EIS Spectrum Analyzer program.Comparison of impedance spectra for the prepared cement concrete samples have made it possible to reveal tendencies in changing spectrum parameters during solidification and subsequent contact with moisture in respect of every type of the sample. An equivalent electrical circuit has been developed that  characterizes physical and chemical processes which are accompanied by charge transfer in cement concrete conglomerate. The paper demonstrates a possibility to use an impedance spectroscopy for solution of a number of actual problems in the field of cement concrete technology problems. Particularly, the problems

  11. Understanding cement mechanical behavior in SAGD wells

    Energy Technology Data Exchange (ETDEWEB)

    Xie, J.; Zahacy, T. A. [C-FER Technologies (Canada)

    2011-07-01

    In the heavy oil industry, the steam assisted gravity drainage process is often used to enhance oil recovery but it can cause cracks in the cement sheath. These cracks are the result of high steam temperatures and thermal expansion. In order to mitigate this risk, improved well designs are required. The aim of this paper is to present the mechanical behavior of the cement sheath during the heating phase. An analysis of the impact of design and operating parameters was conducted through thermal hydraulic and thermal mechanical analyses to assess cement integrity. These analyses were then performed on an example of an SAGD project in the southern part of the Athabasca oilsands region to assess the performance of the cement sheath. Results showed that potential damage to the cement can be reduced by slow heating and a lower Young's modulus cement blend. This paper makes recommendations for optimizing cement design in thermal recovery wells.

  12. Investigation of a Gas-Solid Separation Process for Cement Raw Meal

    DEFF Research Database (Denmark)

    Maarup, Claus; Hjuler, Klaus; Clement, Karsten

    2015-01-01

    The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation efficienc......The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation...

  13. Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations.

    Science.gov (United States)

    Cisneros-Pineda, Olga G; Herrera Kao, Wilberth; Loría-Bastarrachea, María I; Veranes-Pantoja, Yaymarilis; Cauich-Rodríguez, Juan V; Cervantes-Uc, José M

    2014-07-01

    The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone-water than that obtained for methanol-water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol-water system containing MPS at 3wt.% provides the better results during silanization process of HA.

  14. Effect of Fine Steel Slag Powder on the Early Hydration Process of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Hydration heat evolution, non-evaporative water, setting time and SEM tests were performed to investigate the effect of fine steel slag powder on the hydration process of Portland cement and its mechanism.The results show that the effect of fine steel slag powder on the hydration process of Portland cement is closely related to its chemical composition, mineral phases, fineness, etc.Fine steel slag powder retards the hydration of portland cement at early age.The major reason for this phenomenon is the relative high content of MgO , MnO2, P2 O5in steel slag, and MgO solid solved in C3 S contained in steel slag.

  15. Research Of The Influence Of Reftinskii SDPP’S Ash On The Processes Of Cement Stone’S Structure Forming

    Science.gov (United States)

    Zimakova, G. A.; Solonina, V. A.; Zelig, M. P.

    2017-01-01

    The article describes the experimental research of cement stone. Cement stone forming involves highly dispersive mineral additive - ground ash. It is stated that the substitution of some part of cement with activated ash leaves cement strength high. This is possible due to the activity of ash in structure forming processes. Activation of ash provides the increase in its puzzolanic activity, complete hydration processes. it is stated that ash grinding leads to a selective crystallization hydrated neoformations. Their morthology is different on outer and inner surfaces of ash spheres. The usage of ash can provide cement economy on condition that rheological characteristics of concrete stay constant. Besides, the usage of ash will improve physical and mechanic characteristics of cement stone and concrete.

  16. Phase chemistry in process models for cement clinker and lime production

    OpenAIRE

    2014-01-01

    The goal of the thesis is to evaluate if developed phase chemical process models for cement clinker and lime production processes are reliable to use as predictive tools in understanding the changes when introducing sustainability measures. The thesis describes the development of process simulation models in the application of sustainability measures as well as the evaluation of these models. The motivation for developing these types of models arises from the need to predict the chemical and ...

  17. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    Production of cement is an energy intensive process and is the source of considerable CO2emissions. Itis estimated that the cement industry contributes around 8% of total global CO2emissions. CO2is oneof the major greenhouse gases. In the atmosphere, the CO2concentration has increased from 310...... performed recently has focused on CO2capture from fossil fuel-based power plants. Inherently,this process is especially suitablefor cement plants, as CaO used for CO2capture is also a majoringredient for clinker production. Thus, a detailed investigation was carried outto study the applicationof...... the carbonate looping process to the cement industry. In order to study the application of thecarbonate looping process to cement industry, the project work is divided into three scales: 1) atparticle scale (TGA), 2) at reactor scale (Fluid-bed) and 3) at process scale (process modeling Pro/II).The results from...

  18. Project management of business process

    OpenAIRE

    Jovanović, Slaviša

    2011-01-01

    This thesis presents one of the hottest areas in today's software industry, business process management (. Business Process Management has become an important tool for companies to hone their capabilities and business processes to adjust rapid and sudden changes in the marketplace and achieve the set of plans. Thesis is divided into two parts. The first section provides an overview of the scope of business process management through the project approach, historically defined its...

  19. Optimizing the control system of cement milling: process modeling and controller tuning based on loop shaping procedures and process simulations

    Directory of Open Access Journals (Sweden)

    D. C. Tsamatsoulis

    2014-03-01

    Full Text Available Based on a dynamical model of the grinding process in closed circuit mills, efficient efforts have been made to optimize PID controllers of cement milling. The process simulation is combined with an autoregressive model of the errors between the actual process values and the computed ones. Long term industrial data have been used to determine the model parameters. The data include grinding of various cement types. The M - Constrained Integral Gain Optimization (MIGO loop shaping method is utilized to determine PID sets satisfying a certain robustness constraint. The maximum sensitivity is considered as such a criterion. Both dynamical parameters and PID sets constitute the inputs of a detailed simulator which involves all the main process characteristics. The simulation is applied over all the PID sets aiming to find the parameter region that provides the minimum integral of absolute error, which functions as a performance criterion. For each cement type a PID set is selected and put in operation in a closed circuit cement mill. The performance of the regulation is evaluated after a sufficient time period, concluding that the developed design combining criteria of both robustness and performance leads to PID controllers of high efficiency.

  20. Effects of self-blood on the molding process of polymethyl methacrylate bone cement

    Institute of Scientific and Technical Information of China (English)

    Guo Yingjun; Nie Lin; Zhang Wen; Mu Qing

    2014-01-01

    Objective:To evaluate whether the self-blood has influence on the molding process of polymethyl methacrylate (PMMA) bone cement,and to make sure whether it is valuable for the clinical practice.Methods:An in vitro study was performed to evaluate the prolonging-effect of self-blood on PMMA bone cement.The effect of prolonging was evaluated by the dough time (TD) and operable time (To).Moreover,hardness test,squeezing value test and peak temperature test were also conducted to complete the evaluation of this program.Results:The self-blood,especially the plasma,could greatly prolong the handling time of PMMA bone cement without affecting its basic characteristics including hardness,leakage level and peak temperature.On the other hand,we found that in some abnormal conditions,for example with hyperlipemia,self-blood though can also prolong the handling time,would cause some sideeffects.Conclusion:We report a new effective way to prolong the handling time of PMMA bone cement by adding moderate amount of self-blood.But “individualized medicine” should be noticed because some abnormal conditions like hyperlipemia would cause undesired side-effects.

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

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Saghiri

    2013-01-01

    Full Text Available 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-10

    In this study, the microwave materials interactions were studied through dielectric property measurements, process modeling, and lab scale microwave hybrid calcination tests. Characterization and analysis were performed to evaluate material reactions and energy usage. Processing parameters for laboratory scale and larger scale calcining experiments were developed for MAT limestone calcination. Early stage equipment design concepts were developed, with a focus on microwave post heating treatment. The retrofitting of existing rotary calcine equipment in the lime industry was assessed and found to be feasible. Ceralink sought to address some of the major barriers to the uptake of MAT identified as the need for (1) team approach with end users, technology partners, and equipment manufacturers, (2) modeling that incorporates kiln materials and variations to the design of industrial microwave equipment. This project has furthered the commercialization effort of MAT by working closely with an industrial lime manufacturer to educate them regarding MAT, identifying equipment manufacturer to supply microwave equipment, and developing a sophisticated MAT modeling with WPI, the university partner. MAT was shown to enhance calcining through lower energy consumption and faster reaction rates compared to conventional processing. Laboratory testing concluded that a 23% reduction in energy was possible for calcining small batches (5kg). Scale-up testing indicated that the energy savings increased as a function of load size and 36% energy savings was demonstrated (22 kg). A sophisticated model was developed which combines simultaneous microwave and conventional heating. Continued development of this modeling software could be used for larger scale calcining simulations, which would be a beneficial low-cost tool for exploring equipment design prior to actual building. Based on these findings, estimates for production scale MAT calcining benefits were calculated, assuming uptake of

  3. Modeling and Simulation of Process-Machine Interaction in Grinding of Cemented Carbide Indexable Inserts

    Directory of Open Access Journals (Sweden)

    Wei Feng

    2015-01-01

    Full Text Available Interaction of process and machine in grinding of hard and brittle materials such as cemented carbide may cause dynamic instability of the machining process resulting in machining errors and a decrease in productivity. Commonly, the process and machine tools were dealt with separately, which does not take into consideration the mutual interaction between the two subsystems and thus cannot represent the real cutting operations. This paper proposes a method of modeling and simulation to understand well the process-machine interaction in grinding process of cemented carbide indexable inserts. First, a virtual grinding wheel model is built by considering the random nature of abrasive grains and a kinematic-geometrical simulation is adopted to describe the grinding process. Then, a wheel-spindle model is simulated by means of the finite element method to represent the machine structure. The characteristic equation of the closed-loop dynamic grinding system is derived to provide a mathematic description of the process-machine interaction. Furthermore, a coupling simulation of grinding wheel-spindle deformations and grinding process force by combining both the process and machine model is developed to investigate the interaction between process and machine. This paper provides an integrated grinding model combining the machine and process models, which can be used to predict process-machine interactions in grinding process.

  4. Effect of rheology on flow displacement during cementing process in oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, Andre; Naccache, Monica F.; Fonseca, Marcos I. [Dept. Mechanical Engineering. Pontificia Universidade Catolica (PUR-Rio), Rio de Janeiro, RJ (Brazil)], e-mails: mnaccache@puc-rio.br; Miranda, Cristiane R. de; Martins, Andre L.; Aranha, Pedro E. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)], e-mails: crisrichard@petrobras.com.br, aleibsohn@petrobras.com.br, pearanha@petrobras.com.br

    2010-07-01

    This paper describes a set of numerical simulations of the displacement flow of three non-Newtonian fluids through annular eccentric wells. The main application of this work is the studying of drilling and completion processes of oil wells where a cement slurry pushes the drilling mud, used in the drilling process to lubricate the drill and to remove the produced drilling cuts. To avoid contamination, a spacer fluid is usually inserted between them. Both drilling mud and cement slurry behave as non-Newtonian fluids, and the spacer fluid can be Newtonian or non-Newtonian. The analysis of flow and interface configuration between these fluids helps to determine contamination, and is an important tool for the process optimization. The numerical solution of the governing conservation equations of mass and momentum is obtained with the Fluent software, using the finite volume technique and the volume of fluid method. The effects of rheological parameters, density ratios and pumped volume of the spacer fluid are investigated. The results obtained show that the displacement is better when a more viscous spacer fluid is used. The results also show that using lower amounts of the spacer fluid can lead to contamination, which is worse in the smaller gap region of the annular space, in the case of non-rectilinear well. It was also observed that the density ratios play a major role in the cementing operation. (author)

  5. Towards optimization of the silanization process of hydroxyapatite for its use in bone cement formulations

    Energy Technology Data Exchange (ETDEWEB)

    Cisneros-Pineda, Olga G.; Herrera Kao, Wilberth; Loría-Bastarrachea, María I. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Veranes-Pantoja, Yaymarilis [Centro de Biomateriales, Universidad de la Habana, Avenida Universidad, s/n, e/G y Ronda, C.P. 10600 C. de La Habana (Cuba); Cauich-Rodríguez, Juan V. [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Cervantes-Uc, José M., E-mail: manceruc@cicy.mx [Centro de Investigación Científica de Yucatán, A.C., Unidad de Materiales, Calle 43 No. 130, Col. Chuburná de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico)

    2014-07-01

    The aim of this work was to provide some fundamental information for optimization of silanization of hydroxyapatite intended for bone cement formulations. The effect of 3-(trimethoxysilyl) propyl methacrylate (MPS) concentration and solvent system (acetone/water or methanol/water mixtures) during HA silanization was monitored by X-ray diffraction (XRD), FTIR spectroscopy and EDX analysis. The effect of silanized HA on the mechanical properties of acrylic bone cements is also reported. It was found that the silanization process rendered hydroxyapatite with lower crystallinity compared to untreated HA. Through EDX, it was observed that the silicon concentration in the HA particles was higher for acetone–water than that obtained for methanol–water system, although the mechanical performance of cements prepared with these particles exhibited the opposite behavior. Taking all these results together, it is concluded that methanol–water system containing MPS at 3 wt.% provides the better results during silanization process of HA. - Highlights: • Effect of MPS concentration and solvents during HA silanization was studied. • Silanization rendered HA has lower crystallinity compared to untreated HA. • Silicon concentration was higher for acetone than that obtained using methanol. • Methanol–water system containing MPS at 3 wt.% provides the better results.

  6. Process Simulation of Oxy-combustion CO2 Capture in Cement Plant

    OpenAIRE

    2014-01-01

    The objectives of this master thesis have been to model and simulate oxy-combustion CO2 capture in a cement plant. The model developed is a process simulation of the calcination process with varying degree of air in-leakage, where heat is supplied by combustion in an oxygen rich environment, followed by capture of the CO2. The further gas separation after H2O condensation to achieve the required CO2 quality was evaluated. In addition to the process simulations, a review of literature related ...

  7. Chromium behavior during cement-production processes: a clinkerization, hydration, and leaching study.

    Science.gov (United States)

    Sinyoung, Suthatip; Songsiriritthigul, Prayoon; Asavapisit, Suwimol; Kajitvichyanukul, Puangrat

    2011-07-15

    The behavior of chromium during the production of cement clinker, during the hydration of cement and during the leaching of cement mortars was investigated. The microstructures of clinker and mortar properties were investigated using free lime, XRD, SEM/EDS, and TG/DTA techniques. Chromium was found to be incorporated in the clinker phase. The formation of new chromium compounds such as Ca(6)Al(4)Cr(2)O(15), Ca(5)Cr(3)O(12), Ca(5)Cr(2)SiO(12), and CaCr(2)O(7), with chromium oxidation states of +3, +4.6, +5, and +6, respectively, was detected. After the hydration process, additional chromium compounds were identified in the mortar matrix, including Ca(5)(CrO(4))(3)OH, CaCrO(4)·2H(2)O, and Al(2)(OH)(4)CrO(4), with chromium oxidation states of +4.6, +6, and +6, respectively. Additionally, some species of chromium, such as Cr(3+) from Ca(6)Al(4)Cr(2)O(15) and Cr(6+) from CaCr(2)O(7), CaCrO(4)·2H(2)O, and Al(2)(OH)(4)CrO(4), were leached during leaching tests, whereas other species remained in the mortar. The concentrations of chromium that leached from the mortar following U.S. EPA Method 1311 and EA NEN 7375:2004 leaching tests were higher than limits set by the U.S. EPA and the Environment Agency of England and Wales related to hazardous waste disposal in landfills. Thus, waste containing chromium should not be allowed to mix with raw materials in the cement manufacturing process.

  8. Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM) System.

    Science.gov (United States)

    Wan, Bo; Fu, Guicui; Li, Yanruoyue; Zhao, Youhu

    2016-08-10

    The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM) theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC) tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects.

  9. Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM System

    Directory of Open Access Journals (Sweden)

    Bo Wan

    2016-08-01

    Full Text Available The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects.

  10. Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM) System

    Science.gov (United States)

    Wan, Bo; Fu, Guicui; Li, Yanruoyue; Zhao, Youhu

    2016-01-01

    The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM) theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC) tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects. PMID:27517935

  11. Chromium behavior during cement-production processes: A clinkerization, hydration, and leaching study

    Energy Technology Data Exchange (ETDEWEB)

    Sinyoung, Suthatip [Department of Environmental Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Songsiriritthigul, Prayoon [Synchrotron Light Research Institute, PO Box 93 Nakhon Ratchasima, 30000 (Thailand); School of Physics, Suranaree University of Technology, Nakhon Ratchasima, 30000 (Thailand); Asavapisit, Suwimol, E-mail: suwimol_s@hotmail.com [Environmental Technology, School of Energy and Materials, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); National Center of Excellence for Environmental and Hazardous Waste Management, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Kajitvichyanukul, Puangrat, E-mail: puangratk@nu.ac.th [National Center of Excellence for Environmental and Hazardous Waste Management, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Bangkok, 10140 (Thailand); Department of Civil Engineering, Faculty of Engineering, Naresuan University, Phitsanulok, 65000 (Thailand)

    2011-07-15

    Highlights: {yields} Behavior of chromium during cement-production processes. {yields} Formation of new chromium compounds in clinker with chromium oxidation states of +3, +4.6, +5, and +6. {yields} Addition of chromium altered the composition of the clinker phases, setting time, and compressive strength of hydrated mixes. {yields} Cr{sup 3+} and Cr{sup 6} were leached during leaching tests, whereas other species remained in the mortar. - Abstract: The behavior of chromium during the production of cement clinker, during the hydration of cement and during the leaching of cement mortars was investigated. The microstructures of clinker and mortar properties were investigated using free lime, XRD, SEM/EDS, and TG/DTA techniques. Chromium was found to be incorporated in the clinker phase. The formation of new chromium compounds such as Ca{sub 6}Al{sub 4}Cr{sub 2}O{sub 15}, Ca{sub 5}Cr{sub 3}O{sub 12}, Ca{sub 5}Cr{sub 2}SiO{sub 12}, and CaCr{sub 2}O{sub 7}, with chromium oxidation states of +3, +4.6, +5, and +6, respectively, was detected. After the hydration process, additional chromium compounds were identified in the mortar matrix, including Ca{sub 5}(CrO{sub 4}){sub 3}OH, CaCrO{sub 4}.2H{sub 2}O, and Al{sub 2}(OH){sub 4}CrO{sub 4}, with chromium oxidation states of +4.6, +6, and +6, respectively. Additionally, some species of chromium, such as Cr{sup 3+} from Ca{sub 6}Al{sub 4}Cr{sub 2}O{sub 15} and Cr{sup 6+} from CaCr{sub 2}O{sub 7}, CaCrO{sub 4}.2H{sub 2}O, and Al{sub 2}(OH){sub 4}CrO{sub 4}, were leached during leaching tests, whereas other species remained in the mortar. The concentrations of chromium that leached from the mortar following U.S. EPA Method 1311 and EA NEN 7375:2004 leaching tests were higher than limits set by the U.S. EPA and the Environment Agency of England and Wales related to hazardous waste disposal in landfills. Thus, waste containing chromium should not be allowed to mix with raw materials in the cement manufacturing process.

  12. Process development for utilizing asbestos cement waste in rotary kilns for the cement industry. Final report; Erarbeitung eines Verfahrens zur stofflichen Verwertung von zementgebundenen Asbestprodukten in Drehrohroefen fuer die Zementindustrie. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, R.; Kieser, J.; Kraehner, A.

    1999-11-01

    The law for recycling and waste demands the utilization also for waste of asbestos cement (ac). The procedure of thermal utilization of ac in the flame of a rotary cement kiln was developed and patented by the research institute IBU-tec Weimar, Germany. The ac-material has to be pre-pulverized and grinded to a degree of fineness of R{sub 90}<15%. Considerations of safety engineering lead to the idea of common fine grinding of old oil (oo) and ac. This new procedure was searched in FuE-project in 1998/99 (financial support by BMBF). A mash of ac and oo was generated as a utilization product ready for firing which was injected into the flame of the rotary cement kiln. This particles of ac smelt to spherical shaped particles at a temperature above 1500 C. They were utilized by clinker formation. The material and gas stream leaving the kiln does not contain fibres of asbestos. This was demonstrated in a small equipment burning test. The industrial realization concerning cement plant Ruedersdorf, near Berlin, was searched, technologically described and safety engineeringly and financially assessed by a project study. Process-technical and financial advantages were seen for the dry fine grinding. The wet fine grinding with old oil could be used in cement plants using old oil as fuel. (orig.) [German] Das Kreislaufwirtschafts- und Abfallgesetz (1994) fordert u.a. die stoffliche Verwertung auch fuer Asbestzementabfaelle (AZ). Das vom Institut fuer Baustoff- und Umweltschutz-Technologie Weimar 1995 entwickelte und patentierte Verfahren zur thermischen Verwertung von AZ in der Flamme eines Zementdrehrohrofens erfuellt diese Forderung. Das AZ-Material muss vorzerkleinert und bis zur Rohmehlfeinheit (R{sub 90}<15%) feingemahlen werden. Sicherheitstechnische Ueberlegungen fuehrten zu der Idee, die Feinmahlung zusammen mit Altoel (AOe) zu erproben. Diese Verfahrensvariante wurde im Rahmen eines FuE-Projektes 1998/99 untersucht (finanzielle Foerderung durch das BMBF). Als

  13. Review of technologies for mercury removal from flue gas from cement production processes

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

    2012-01-01

    to the adsorption of mercury on the solids in the cold zone. However, recirculation of the kiln dust to the kiln will cause release of the captured mercury. The mercury chemistry in cement kiln systems is complicated and knowledge obtained from power plants and incinerators cannot be directly applied in cement......Mercury is a pollutant of concern and mercury emissions from cement plants are under environmental regulation. After coal-fired power plants, mercury emissions from cement and mineral production are the second largest anthropogenic sources. Compared to fuels, cement raw materials are the major...... sources of mercury in the cement kiln flue gas. Cement plants are quite different from power plants and waste incinerators regarding the flue gas composition, temperature, residence time, and material circulation. Cement kiln systems have some inherent ability to retain mercury in the solid materials due...

  14. Laser-radiation scattering by cement in the process of hydration: simulation of the dynamics and experiment.

    Science.gov (United States)

    Gorsky, M P; Maksimyak, P P; Maksimyak, A P

    2012-04-01

    This paper discusses simulation of speckle-field dynamics during coherent light scattering by a cement surface in the process of hydration. Cement particles are represented by the spheres whose sizes and reflection indices are changing during the hydration process. The study of intensity fluctuations of scattered coherent radiation is a suitable technique for the analysis of both fast and slow processes of mineral binder hydration and formation of polycrystalline structures in the process of hardening. The results of simulation are in good agreement with the experimental data.

  15. Effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions.

    Science.gov (United States)

    Lv, Dong; Zhu, Tianle; Liu, Runwei; Lv, Qingzhi; Sun, Ye; Wang, Hongmei; Liu, Yu; Zhang, Fan

    2016-09-01

    The effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions were systematically investigated in a cement production line in Beijing. The results show that co-processing the sewage sludge was helpful to reduce NOx emission, which primarily depends on the NH3 amount released from the sewage sludge. Meanwhile, NOx and NH3 concentrations in the flue gas have a negative correlation, and the contribution of feeding the sewage sludge to NOx removal decreased with the increase of injection amount of ammonia water in the SNCR system. Therefore, it is suggested that the injection amount of ammonia water in SNCR system may reduce to cut down the operating costs during co-processing the sewage sludge in cement kiln. In addition, the emission of total PAHs seems to increase with the increased amount of the sewage sludge feeding to the cement kiln. However, the distributions of PAHs were barely changed, and lower molecular weight PAHs were mainly distributed in gaseous phase, accounted for the major portion of PAHs when co-processing sewage sludge in cement kiln.

  16. Synthesis of partial-stabilized cement (PSC) via sol-gel process.

    Science.gov (United States)

    Wang, Wen-Hsi; Lee, Yuan-Ling; Lin, Chun-Pin; Lin, Feng-Huei

    2008-06-15

    The traditional method of preparing partial-stabilized cement (PSC), which is a kind of calcium silicate cement, is through power mixing method. Low reaction efficiency and initial strength limited the application of PSC as a dental root-end filling material. This study provides a one-step sol-gel process for the synthesis of PSC. A complexing ligand is used for tuning down the activity of aluminum sec-butoxide (ASB) in order to avoid possible self-polymerization. After the modification with complex ligand, there is no residue of reactant observed on the analysis of SDT, and bonding between metal atoms is observed in the FTIR spectrum. Each component of PSC is identified using XRD. The hydration product, which is called portlandite, of sol-gel-synthesized PSC is observed after 1 day of hydration, and crystallinity of portlandite increases much faster than that of traditional PSC. The initial strength of sol-gel-synthesized PSC achieves detectable level 24 h earlier than that of traditional PSC; microhardness value of sol-gel-synthesized PSC at 7th day is 2.98 HV, which is much higher than that of traditional PSC (2.05 HV). PSC is successfully synthesized and the initial strength of PSC is improved by this modified sol-gel process.

  17. Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash.

    Science.gov (United States)

    Liu, Guorui; Zhan, Jiayu; Zhao, Yuyang; Li, Li; Jiang, Xiaoxu; Fu, Jianjie; Li, Chunping; Zheng, Minghui

    2016-07-01

    Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.

  18. Effect of Nano-TiO2 Addition on the Hydration and Hardening Process of Sulphoaluminate Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; LI Hainan; MEI Junpeng; OUYANG Pei

    2015-01-01

    The influences of nano-TiO2 on the setting time, hydration process, hydration products and morphology of sulphoaluminate cement were studied by Vicat apparatus, isothermal calorimetry, X-ray diffraction (XRD), thermal analysis and scanning electron microscopy (SEM). The experimental results show that the incorporation of nano-TiO2 can obviously promote the setting and hardening process of sulphoaluminate cement, and shorten the interval between the initial and ifnal setting time, the hydration induction period of sulphoaluminate cement is significantly shortened and the acceleration period begins immediately, but the hydration exothermic rate at hydration stationary phase is not obviously impacted. The nano-TiO2 additives have inlfuence on the formation rate and degree of crystallinity, but do not affect the type of hydration process. The structure of hydration products is compact at middle age, but their content and microstructure do not change.

  19. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  20. FUZZY LOGIC CONTROLLER AS MODELING TOOL FOR THE BURNING PROCESS OF A CEMENT PRODUCTION PLANT

    Directory of Open Access Journals (Sweden)

    P.B. Osofisan

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: A comprehensive optimisation of the cement production process presents a problem since the input variables as well as the output variables are non-linear, interdependent and contain uncertainties. To arrive at a solution, a Fuzzy Logic controller has been designed to achieve a well-defined relationship between the main and vital variables through the instrumentality of a Fuzzy Model. The Fuzzy Logic controller has been simulated on a digital computer using MATLAB 5.0 Fuzzy Logic Tool Box, using data from a local cement production plant.

    AFRIKAANSE OPSOMMING: Die omvattende optimisering van 'n proses wat sement vervaardig, word beskryf deur nie-linieêre inset- en uitsetveranderlikes wat onderling afhanklik is, en ook van onsekere aard is. Om 'n optimum oplossing te verkry, word 'n Wasigheidsmodel gebruik. Die model word getoets deur gebruik te maak van die MATLAB 5.0 Fuzzy Logic Tool Box en data vanaf 'n lokale sementvervaardigingsaanleg.

  1. U.S. EPA requires Cupertino cement company to report toxic chemicals, commit to environmental projects

    Science.gov (United States)

    SAN FRANCISCO - The U.S. Environmental Protection Agency announced a settlement with Lehigh Southwest Cement Company for failing to properly report releases of toxic chemicals at its Cupertino, Calif. plant. The company is required to pay a $47,600

  2. Process-based project proposal risk management

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2016-12-01

    Full Text Available We all are aware of the organizational omnipresence. Projects within the organizations are ubiquitous too. Projects achieve their goals successfully if they are planned, scheduled, controlled and implemented well. The project lifecycle of initiating, planning, scheduling, controlling and implementing are very well-planned by project managers and the organizations. Successful projects have well-developed risk management plans to deal with situations impacting projects. Like any other organisation, a university does try to access funds for different purposes too. For such organisations, running a project is not the issue, rather getting a project proposal approved to fund a project is the key. Project proposal processing is done by the nodal office in every organisation. Usually, these nodal offices help in administration and submission of a project proposal for accessing funds. Seldom are these nodal project offices within the organizations facilitate a project proposal approval by proactively reaching out to the project managers. And as project managers prepare project proposals, little or no attention is made to prepare a project proposal risk plan so as to maximise project acquisition. Risk plans are submitted while preparing proposals but these risk plans cater to a requirement to address actual projects upon approval. Hence, a risk management plan for project proposal is either missing or very little effort is made to treat the risks inherent in project acquisition. This paper is an integral attempt to highlight the importance of risk treatment for project proposal stage as an extremely important step to preparing the risk management plan made for projects corresponding to their lifecycle phases. Several tools and techniques have been proposed in the paper to help and guide either the project owner (proposer or the main organisational unit responsible for project management. Development of tools and techniques to further enhance project

  3. Characterization of a calcium phosphate cement based on alpha-tricalcium phosphate obtained by wet precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Thurmer, M.B.; Diehl, C.E.; Vieira, R.S.; Coelho, W.T.G.; Santos, L.A., E-mail: monicathurmer@yahoo.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia de Materiais

    2012-07-01

    There are several systems of calcium phosphate cements being studied. Those based on alpha-tricalcium phosphate are of particular interest. After setting they produce calcium deficient hydroxyapatite similar to bone like hydroxyapatite. This work aims to obtain alpha-tricalcium phosphate powders by the wet precipitation process, using calcium nitrate and phosphoric acid as reagents. This powder was characterized by infrared spectroscopy, X-ray diffraction and particle size distribution. In order to prepare the calcium phosphate cement, the powder was mixed with an accelerator in an aqueous solution. The mechanical properties of the cement were assessed and it was evaluated by means of apparent density, X-ray diffraction and scanning electron microscopy. The described method produced crystalline alpha-tricalcium phosphate as the major phase. The calcium phosphate cement showed high values of compression strength (50 MPa). The soaking of the cement in a simulated body fluid (SBF) formed a layer of hydroxyapatite like crystals in the surface of the samples. (author)

  4. Sustainable Building through Project Planning Process

    Directory of Open Access Journals (Sweden)

    Anuar Alias

    2014-10-01

    Full Text Available Planning process has a significant impact on the ability of a construction project to success. This is the stage where the detailed directions are given which would affect thewhole course of the project. The process is argued to be the most crucial stage which the principles of sustainability are integrated throughout the whole life of building. The purpose of this research was to investigate the Malaysian building project stakeholders’ perspectives on the most significant strategies to integrate sustainability principles into thewhole life of building through the project planning process. From the review of available literatures, there are 21 strategies to integrate sustainability principles during a building project planning process have been unveiled. A total of 357 Malaysian project stakeholderswho have been directly involved in sustainable building project and/or the stakeholders who are judged to be knowledgeable on the project were selected to be contributed for questionnaire survey. The collected data were analyzed using cronbach’s alpha measurement to assess their internal reliability, and frequency and descriptive analysis tomeasure the relative importance of the factors. The result shows that all the 21 strategies (the factors to integrate sustainability during a project planning process were identified by the respondents to be very crucial to be implemented throughout the planning process ofa sustainable building project in Malaysia. This paper offers ideas and recommendations on the sustainability integration strategies to be practiced throughout the project planningprocess towards delivering a successful sustainable building project. The concept is very useful to be a starting point for the development of a practical ‘Sustainability IntegrationFramework’ during the planning process of a sustainable building project in the future.Keywords: Sustainable Building Project; Construction Project; Project Planning Process

  5. Environmental Assessment of Different Cement Manufacturing Processes Based on Emergy and Ecological Footprint Analysis

    Science.gov (United States)

    Due to its high environmental impact and energy intensive production, the cement industry needs to adopt more energy efficient technologies to reduce its demand for fossil fuels and impact on the environment. Bearing in mind that cement is the most widely used material for housin...

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

    Science.gov (United States)

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

    2015-10-01

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

  7. Process-based software project management

    CERN Document Server

    Goodman, F Alan

    2006-01-01

    Not connecting software project management (SPM) to actual, real-world development processes can lead to a complete divorcing of SPM to software engineering that can undermine any successful software project. By explaining how a layered process architectural model improves operational efficiency, Process-Based Software Project Management outlines a new method that is more effective than the traditional method when dealing with SPM. With a clear and easy-to-read approach, the book discusses the benefits of an integrated project management-process management connection. The described tight coup

  8. Cement Conundrum

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China aims to streamline the crowded cement industry Policymakers are looking to build a concrete wall around the cement-making industry as they seek to solidify the fluid cement market and cut excessive production.

  9. A New Kind of Eco-Cement Made of Cement Kiln Dust and Granular Blast Furnace Slag

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A research project was conducted to manufacture eco-cement for sustainable development using cement kiln dust( CKD ) and granular blast furnace slag( GBFS ).In the project, the burning process and mineral compositions of CKD clinker were investigated.Dife rent mineralizers such as CaSO4 and CaF2 , sulfur and alkali content were considered.The strength of CKD and GBFS eco-cement were evaluated.The results indicate the CKD clinker can not only form ordinary cement clinker minerals such as C3 S, C2 S and C4 AF, but also form strength to the Portland cement grade 32.5 when blend proportion is properly applied.

  10. Investment Projects Evaluation in Decision Making Process

    Directory of Open Access Journals (Sweden)

    Dunja Škalamera-Alilović

    2005-08-01

    Full Text Available One of the most important criteria in classifying investment projects is economic dependence between new and existing projects. Economic dependence causes the neccessity of specific information in decision making process. The prerequisite of shaping incremental effects projections is to take opportunity effects, caused by economic dependence, into account. Basic principles of risk estimation that are well known in the field of financial assets, are concerning real investments as well. An enterprise can be viewed as portfolio of investment projects that cannot be perfectly diversified and where market risk is not the most important risk. In the field of real investments, individual risk and added risk to the total risk of enterprise, besides market risk, have to be estimated. This paper explains basic principles of risk estimation in the field of investment projects in the selection of project variants. It researches types of economic dependence among various investment projects and their influence into decision making process.

  11. SNF project engineering process improvement plan

    Energy Technology Data Exchange (ETDEWEB)

    KELMENSON, R.L.

    1999-05-24

    This Engineering Process Improvement Plan documents the activities and plans to be taken by the SNF Project (the Project) to support its engineering process and to produce a consolidated set of engineering procedures that are fully compliant with the requirements of HNF-PRO-1819 (1819). These requirements are imposed on all engineering activities performed for the Project and apply to all life-cycle stages of the Project's systems, structures and components (SSCs). This Plan describes the steps that will be taken by the Project during the transition period to ensure that new procedures are effectively integrated into the Project's work process as these procedures are issued. The consolidated procedures will be issued and implemented by September 30, 1999.

  12. Long-term model-based projections of energy use and CO2emissions from the global steel and cement industries

    NARCIS (Netherlands)

    Van Ruijven, Bas J.; Van Vuuren, Detlef P.; Boskaljon, Willem; Neelis, Maarten L.; Saygin, Deger; Patel, Martin K.

    2016-01-01

    This paper presents a global simulation-model for the steel and cement industries. The model covers the full modelling chain from economic activity, to materials consumption, trade, technology choice, production capacity, energy use and CO2emissions. Without climate policy, the future projections ba

  13. Variations and factors that influence the formation of polychlorinated naphthalenes in cement kilns co-processing solid waste.

    Science.gov (United States)

    Jin, Rong; Zhan, Jiayu; Liu, Guorui; Zhao, Yuyang; Zheng, Minghui

    2016-09-05

    Pilot studies of unintentionally produced pollutants should be performed before waste being co-processed in cement kilns. Polychlorinated naphthalene (PCN) formation and emission from cement kilns co-processing sorted municipal solid waste, sewage sludge, and waste acid, however, have not previously been studied. Here, PCNs were analyzed in stack gas samples and solid samples from different stages of three cement production runs. PCN destruction efficiencies were higher when waste was co-processed (93.1% and 88.7% in two tests) than when waste was not co-processed (39.1%), so co-processing waste would not increase PCN outputs. The PCN concentrations were higher in particle samples from the C1 preheater and stages at back end of kiln than in particle samples from other stages, suggesting that cyclone preheater and back end of kiln should be focused for controlling PCN emissions. Besides that, based on the variation of PCN concentrations and corresponding operating conditions in different stages, the temperature, feeding materials, and chlorine content were suggested as the main factors influencing PCN formation. The PCN homologue and congener profiles suggested chlorination and dechlorination were the main PCN formation and decomposition pathways, and congeners CN-23, CN-46, and CN-59 appear to be appropriate indicators of PCNs emitted from coal-burning sources.

  14. Mars Aqueous Processing System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mars Aqueous Processing System (MAPS) is an innovative method to produce useful building materials from Martian regolith. Acids and bases produced from the regolith...

  15. Mars Aqueous Processing System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mars Aqueous Processing System (MAPS) is a novel technology for recovering oxygen, iron, and other constituents from lunar and Mars soils. The closed-loop...

  16. Processing of diamond enhanced cemented tungsten carbide insert for rock drilling

    Institute of Scientific and Technical Information of China (English)

    LIU Bao-chang; SUN You-hong; ZHANG Zu-pei

    2004-01-01

    This paper introduced the structure, component and sintering procedure of the Diamond/WC-Co composite insert fabricated by high pressure and high temper ature (HPHT) method as well as by hot pressing method. In HPHT method, to avoid breakage and delamination of the diamond layer, two transition layers were added between the most outer diamond layer and the WC-Co body. The transition layers compensate for differences in thermal expansion coefficient and elastic modulus of diamond layer and WC-Co substrate. Thus reduces the residual stress induced by cooling the inserts from sintering temperature to room temperature. In hot pressing method, to decrease sintering temperature so as to protect diamond, an active sintering process which achieved by adding nickel and phosphorus into the starting mixed powder is adopted. To increase the toughness of the inserts to resist breakage, proper amount of rare earth compound, LaNi5 and CeO2, are added into the original mixed powder, too. Laboratory tests indicated that both of the diamond enhanced inserts fabricated by HPHT method and by hot pressing method have relatively high hardness and impact toughness, while their wear resistance is about hundreds of times greater than that of conventional cemented tungsten carbide inserts. The results of field drilling test indicated that the diamond enhanced inserts can meet the demands of rotary percussion drilling.

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

    Science.gov (United States)

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

    2014-10-01

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

  18. Influence of chemical bonding of chlorides with aluminates in cement hidratation process on corrosion steel bars in concrete

    OpenAIRE

    2010-01-01

    The presence of chlorides in concrete is a permanent subject of research because they cause corrosion of steel bars. Chlorides added to the concrete during preparation, as accelerators of the bonding of cement minerals process, enter into reaction with aluminates, creating a phase known as chloroaluminate hydrates. In everyday conditions the product of chemical bonding between chlorides and aluminates is usually monochloridealuminate C3A·CaCl2·Hx, better known as Friedel's salt. In this paper...

  19. GMTI processing using back projection.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2013-07-01

    Backprojection has long been applied to SAR image formation. It has equal utility in forming the range-velocity maps for Ground Moving Target Indicator (GMTI) radar processing. In particular, it overcomes the problem of targets migrating through range resolution cells.

  20. Human-Systems Integration Processes (HSIP) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In FY12, this project removed the commercial-specific content from the Commercial Human-Systems Integration Design Processes (CHSIP), identified gaps in the...

  1. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2002-01-23

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

  2. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

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

  3. Quantification of the Reduced Environmental Impacts with Use of Co-Processing in Cement Kilns in India

    Directory of Open Access Journals (Sweden)

    Ankur Tiwary

    2014-10-01

    Full Text Available Coupled with resource conservation and reduced carbon emissions, co-processing technology is a preferable alternative for sound and environmental friendly waste disposal over incinerators & non-scientific methods. It is not only solution to the waste disposal menace, but also reduces burden on secured landfills & TSDFs. Apart from using energy and material value of wastes, co-processing not only fixes the inorganic content of the wastes within the clinker, but also, it destroys the wastes completely due to high temperature and long residence time, avoiding need of further processing as in case of incineration. Trial run identifies wastes suitable for co-processing, source emission monitoring assesses environmental impacts and the quantification of reduced environmental impacts gives a clear picture of actual benefits of co-processing. The results show that the suggested process is efficient, economized and environmental friendly, particularly for a populated country, such as India, as there was no adverse effect on quality of cement, stack emission and air quality of environment due to co-processing of variety of identified wastes in cement kiln. Also, the quantified data of coal saved, CO2 emissions reduced & landfill volume avoided by the waste utilization will help in convincing all the stakeholders that co-processing of waste is the best environmentally sound technology for waste disposal. DOI: http://dx.doi.org/10.5755/j01.erem.69.3.6736

  4. Modelling the effect of electrical current flow on the hydration process of cement-based materials

    NARCIS (Netherlands)

    Susanto, A.; Koleva, D.A.; Van Breugel, K.; Koenders, E.A.B.

    2014-01-01

    Stray current is essentially an electrical current “leakage” from metal conductors and electrical installations. When it flows through cement-based systems, electrical energy is converted to thermal energy that causes increasing temperature due to Joule heating phenomena. The aim of this paper is to

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

    NARCIS (Netherlands)

    Zemskov, S.V.; Ahmad, B.; Copuroglu, O.; Vermolen, F.J.

    2013-01-01

    In the current research, a mathematical model for the post-damage improvement of the carbonated blast furnace slag cement (BFSC) exposed to accelerated carbonation is constructed. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate, whi

  6. Optimization and validation of a chemical process for uranium, mercury and cesium leaching from cemented radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Reynier, N.; Lastra, R.; Laviolette, C.; Bouzoubaa, N., E-mail: nicolas.reynier@canada.ca [Natural Resources Canada, CanmetMINING, Ottawa, Ontario (Canada); Chapman, M. [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2015-12-15

    Canadian Nuclear Laboratories (CNL) is developing a treatment and long-term management strategy for a legacy cemented radioactive waste that contains uranium, mercury, and fission products. Extracting the uranium would be advantageous for decreasing the waste classification and reducing the cost of long-term management. The chemical leachability of 3 key elements (U, Hg, and Cs) from a surrogate cemented waste (SCW) was studied with several lixiviants. The results showed that the most promising approach to leach and recover U, Hg, and Cs is the direct leaching of the SCW with H{sub 2}SO{sub 4} in strong saline media. Operating parameters such as particle size, temperature, pulp density, leaching time, acid and salt concentrations, number of leaching/washing steps, etc. were optimized to improve key elements solubilization. Sulfuric leaching in saline media of a SCW (U5) containing 1182 ppm of U, 1598 ppm of Hg, and 7.9 ppm of Cs in the optimized conditions allows key elements solubilisation of 98.5 ± 0.4%, 96.6 ± 0.1%, and 93.8 ± 1.1% of U, Hg, and Cs, respectively. This solubilization process was then applied in triplicate to 7 other SCWs prepared with different cements, liquid ratios, and at different aging times and temperatures. Concentrated sulfuric acid is added to the slurry until the pH is about 2, which causes the complete degradation of cement and the formation of CaSO{sub 4}. Sulfuric acid is particularly useful because it produces a leachate that is amenable to conventional ion exchange technology for the separation and recovery of uranium. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lu, Hongyou [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Williams, Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-07-01

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

  8. PROCESSING OF ZIRCONIA AND CALCIUM ALUMINATE CEMENT MIXTURES BY SPARK PLASMA SINTERING

    Directory of Open Access Journals (Sweden)

    Y. L. Bruni

    2015-12-01

    Full Text Available Spark Plasma sintering (SPS was applied for the densification of Calcia stabilized ZrO2 based composites obtained from mixtures of pure zirconia (m-ZrO2 and calcium aluminate cement (HAC. Two commercial powders of pure zirconia were employed as reactants. One of these powders had a coarse mean particle size (d50 = 8 μm and the other was a submicrometer sized power (d50 = 0.44 μm. Several compositions containing different proportions of HAC (5 to 30 mol. % CaO in ZrO2 were sintered by SPS at temperatures between 1200 and 1400ºC under a pressure of 100 MPa during 10 min. The effect of processing conditions on phase composition, densification, microstructure and Vickers hardness of the obtained composites was examined. SPS significantly enhanced the densification in both type of composites (relative density > 93 % as compared to those previously produced by conventional sintering. Composites with low CaO content consisted of mixtures of c-ZrO2, (Ca0.15Zr0.85O1.85, unreacted m-ZrO2 and calcium dialuminate (CaAl4O7 or CA2. The highest hardness was determined for composites sintered at 1400ºC being related to the maximum relative density (~ 99 %. High densification of composites with 30 mol. % CaO composed by similar proportions of CaAl4O7 and c-ZrO2 were obtained even at 1200ºC but led to a slightly lower hardness. In general, the use of the finer m-ZrO2 powder contributed to increase both the c-ZrO2 content and densification of composite sintered at a relatively lower temperature. For these composites, best hardness (Hv near to 10 GPa resulted when the microstructure consisted of a fine grained ZrO2 matrix surrounding the dispersed CaAl4O7 grains instead of large interconnection between grains of both phases existed.

  9. Influence of chemical bonding of chlorides with aluminates in cement hidratation process on corrosion steel bars in concrete

    Directory of Open Access Journals (Sweden)

    Bikić Farzet H.

    2010-01-01

    Full Text Available The presence of chlorides in concrete is a permanent subject of research because they cause corrosion of steel bars. Chlorides added to the concrete during preparation, as accelerators of the bonding of cement minerals process, enter into reaction with aluminates, creating a phase known as chloroaluminate hydrates. In everyday conditions the product of chemical bonding between chlorides and aluminates is usually monochloridealuminate C3A·CaCl2·Hx, better known as Friedel's salt. In this paper, the influence of chemical bonding of chlorides with aluminates during the process of cement hydration on corrosion of steel bars in concrete was investigated. The process of chlorides bonding with aluminates yielding monochloride aluminate is monitored by XRD analyses. It was found that the amount of chlorides bonding with aluminates increases with an increase of temperature, and as a result, reduces the amount of 'free' chlorides in concrete. Potentiodynamic measurements have shown that increase in temperature of the heat treatment of working electrodes by chlorides leads to a reduction of steel bars corrosion as a result of either the increase of the monochloride-aluminate content or the decrease of free chlorides amount. Chlorides bound in chloroaluminate hydrates do not cause activation of steel bars corrosion in concrete. It was also proven that the increase of free chlorides concentration in the concrete leads to intensification of steel bars corrosion. This additionally approves that free chlorides are only the activators of process of steel bars corrosion in the concrete.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-05-20

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

  11. Accumulating project management knowledge through process theory

    NARCIS (Netherlands)

    Niederman, Fred; March, Salvatore T.; Mueller, Benjamin

    2014-01-01

    This paper describes how the general notion of process theory can provide a foundational component in a portfolio of project management theories. The paper begins by outlining a variety of views pertaining to the nature of theory and theory development. This forms a basis for understanding how theor

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

    Science.gov (United States)

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

    2009-10-01

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

  13. Tympanoplasty with ionomeric cement

    DEFF Research Database (Denmark)

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those...... of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  14. Cement and concrete

    Science.gov (United States)

    Corley, Gene; Haskin, Larry A.

    1992-01-01

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

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

    Science.gov (United States)

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

    2014-09-01

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

  16. Effect of temperature on the hydration process and strength development in blends of Portland cement and activated coal gangue or fly ash

    Institute of Scientific and Technical Information of China (English)

    Pei-ming WANG; Xian-ping LIU

    2011-01-01

    This paper describes the results of an investigation into the effect of the variation of curing temperatures between 0 and 60 ℃ on the hydration process,pore structure variation,and compressive strength development of activated coal gangue-cement blend (ACGC).Hardened ACGC pastes cured for hydration periods from 1 to 360 d were examined using the non-evaporable water method,thermal analysis,mercury intrusion porosimetry,and mechanical testing.To evaluate the specific effect of activated coal gangue (ACG) as a supplementary cementing material (SCM),a fly ash-cement blend (FAC) was used as a control.Results show that raising the curing temperature accelerates pozzolanic reactions involving the SCMs,increasing the degree of hydration of the cement blends,and hence increasing the rate of improvement in strength.The effect of curing temperature on FAC is greater than that on ACGC.The pore structure of the hardened cement paste is improved by increasing the curing temperature up to 40 ℃,but when the curing temperature reaches 60 ℃,the changing nature of the pore structure leads to a decrease in strength.The correlation between compressive strength and the degree of hydration and porosity is linear in nature.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-11-01

    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).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-11-01

    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).

  19. CEMEX: Cement Manufacturer Saves 2.1 Million kWh Annually with a Motor Retrofit Project

    Energy Technology Data Exchange (ETDEWEB)

    2005-11-01

    This DOE Industrial Technologies Program spotlight describes how the CEMEX cement manufacturing plant in Davenport, California, saves 2 million kWh and $168,000 in energy costs annually by replacing 13 worn-out motors with new energy-efficient ones.

  20. CEMEX: Cement Manufacturer Saves 2.1 Million kWh Annually with a Motor Retrofit Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-06-25

    This DOE Industrial Technologies Program spotlight describes how the CEMEX cement manufacturing plant in Davenport, California, saves 2 million kWh and $168,000 in energy costs annually by replacing 13 worn-out motors with new energy-efficient ones.

  1. 7th NCB international seminar on cement and building materials. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Topics covered include: mining and mine environment (including CO{sub 2} mitigation in cement concrete industries), and project engineering and management (in volume 1); productivity enhancement and process optimisation (upgrading/cost reduction, grinding/refractories, process optimisation and control, and maintenance) (in volume 2); plant environment and pollution control (including global climate change) performance of concrete, and Portland and blended cements (in volume 3); special cements and binders, total quality management and energy management (in volume 4); and supplementary papers in volume 5.

  2. Acid attack on hydrated cement — Effect of mineral acids on the degradation process

    Energy Technology Data Exchange (ETDEWEB)

    Gutberlet, T.; Hilbig, H.; Beddoe, R.E., E-mail: robin.beddoe@tum.de

    2015-08-15

    During acid attack on concrete structural components, a degraded layer develops whose properties as a protective barrier are decisive for durability. {sup 29}Si NMR spectroscopy and {sup 27}Al NMR spectroscopy were used with XRD to investigate the degraded layer on hardened cement paste exposed to HCl and H{sub 2}SO{sub 4}. The layer comprises an amorphous silica gel with framework silicates, geminate and single silanol groups in which Si is substituted by Al. Amorphous Al(OH){sub 3} and Fe(OH){sub 3} are present. The gel forms by polycondensation and cross-linking of C-A-S-H chains at AlO{sub 4} bridging tetrahedra. In the transition zone between the degraded layer and the undamaged material, portlandite dissolves and Ca is removed from the C-A-S-H phases maintaining their polymer structure at first. With HCl, monosulphate in the transition zone is converted into Friedel's salt and ettringite. With H{sub 2}SO{sub 4}, gypsum precipitates near the degradation front reducing the thickness of the transition zone and the rate of degradation.

  3. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-10-23

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

  4. Methodological and Practical Considerations for DevelopingMultiproject Baselines for Electric Power and Cement Industry Projects inCentral America

    Energy Technology Data Exchange (ETDEWEB)

    Murtishaw, Scott; Sathaye, Jayant; Galitsky, Christina; Dorion,Kristel

    2004-09-02

    The Lawrence Berkeley National Laboratory (Berkeley Lab) andthe Center for Sustainable Development in the Americas (CSDA) conductedtechnical studies and organized two training workshops to developcapacity in Central America for the evaluation of climate changeprojects. This paper describes the results of two baseline case studiesconducted for these workshops, one for the power sector and one for thecement industry, that were devised to illustrate certain approaches tobaseline setting. Multiproject baseline emission rates (BERs) for themain Guatemalan electricity grid were calculated from 2001 data. Inrecent years, the Guatemalan power sector has experienced rapid growth;thus, a sufficient number of new plants have been built to estimateviable BERs. We found that BERs for baseload plants offsetting additionalbaseload capacity ranged from 0.702 kgCO2/kWh (using a weighted averagestringency) to 0.507 kgCO2/kWh (using a 10th percentile stringency),while the baseline for plants offsetting load-followingcapacity is lowerat 0.567 kgCO2/kWh. For power displaced from existing load-followingplants, the rate is higher, 0.735 kgCO2/kWh, as a result of the age ofsome plants used for meeting peak loads and the infrequency of their use.The approved consolidated methodology for the Clean Development Mechanismyields a single rate of 0.753 kgCO2/kWh. Due to the relatively smallnumber of cement plants in the region and the regional nature of thecement market, all of Central America was chosen as the geographicboundary for setting cement industry BERs. Unfortunately, actualoperations and output data were unobtainable for most of the plants inthe region, and many data were estimated. Cement industry BERs rangedfrom 205 kgCO2 to 225 kgCO2 per metric ton of cement.

  5. Cement corrosion in oil and gas wells. Literature study; Zementkorrosion bei Oel- und Gasbohrungen. Literaturstudie

    Energy Technology Data Exchange (ETDEWEB)

    Plank, J.; Brandl, A. [Technische Univ. Muenchen (Germany). Lehrstuhl fuer Bauchemie

    2009-07-15

    The goal of DGMK-project 652 is to determine the main factors which are responsible for cement corrosion in oil and gas wells, and to develop concepts for improvements with respect to the cement slurry formulation, the cementing process and the impact of factors such as temperature, electrolyte containing reservoir fluids, cement admixtures, sour gas, CO{sub 2} acids etc. To determine the state of the art, a literature survey in relevant journals and monographies with the help of data banks was performed. The results are presented in this report. At first, a detailed description of the chemistry and mineralogy of oil well cement and its corrosion processes is given. Then, current experiences from conventional concrete technology as well as the oilfield are presented. The state of art of cement corrosion in the oilfield was investigated. Overall, little literature about cement corrosion in oil and gas wells exists. In particular, only a few field reports were ever published. The subject of cement corrosion is mainly presented in the form of laboratory tests simulating certain conditions and using common analytical methods. (orig.)

  6. The hardening of Portland cement studied by ? NMR stray-field imaging

    Science.gov (United States)

    Nunes, Teresa; Randall, E. W.; Samoilenko, A. A.; Bodart, P.; Feio, G.

    1996-03-01

    Hydration and hardening processes of Portland cement (type I) were studied by analysis of the one-dimensional projections (profiles) obtained periodically with the 0022-3727/29/3/044/img8 stray-field imaging technique over two days. The influence of additives, such as gypsum, in Portland cement (type IA) was also investigated. The decay of the signal intensity as a function of time was found to be bi-exponential for type I and mono-exponential for type IA.

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

    Science.gov (United States)

    Almuhim, Khalid Salman

    Background. Little is known about the long-term clinical bonding effectiveness of the Fiber-reinforced composite (FRC) posts cemented with self-etch adhesive systems. Bond stability and longevity of the cemented post are adversely affected by physical and chemical factors over time, such as expansion and contraction stresses caused by thermal changes and occlusal load. This clinical condition can be simulated in vitro by thermocyclic loading; and bonding effectiveness can be evaluated by applying the micropush out test. Therefore, more in vitro studies are needed to evaluate the bond strength of the fiber posts cemented with different resin cement systems after simulating the artificial aging induced by thermocycling. The aim of this study was to compare the microtensile bond strength of two different resin cement systems (total etch, and self-etch resin cement system) used for cementation of fiber reinforced composite posts in three different aging periods using thermocycling. Methods. Following IRB approval, sixty freshly extracted bicuspid single rooted natural teeth were endodontically treated, and the post-spaces were prepared to receive a fiber-post cemented with either a total etch resin cement (Rely-X Ultimate) or with a self-etch resin cement (Rely-X Unicem). No thermocycling, 20,000 and 40,000 cycles was used to age the specimens. Teeth were randomly allocated into six different groups: G1 - Control: Rely-X Ultimate cement with no thermocycling. G2: Rely-X Ultimate cement with 20,000 thermocycling. G3: Rely-X Ultimate cement with 40,000 thermocycling. G4: Rely-X Unicem cement. G5: Rely-X Unicem cement. G6: Rely-X Unicem cement. Microtensile bond strength determined using a micropush out test on a universal testing machine (MTS). Additionally, the failure mode of each specimen was observed under a stereomicroscope (Olympus) at 40x magnification. Finally, one representative sample was randomly selected from each of the five failure modes for scanning

  8. Kiln process impact of alternative solid fuel combustion in the cement kiln main burner - Mathematical modelling and full-scale experiment

    OpenAIRE

    Ariyaratne, Hiromi Wijesinghe; Melaaen, Morten Christian; Tokheim, Lars André; Manjula, Edirisinghe V. P. J.

    2014-01-01

    Increased use of alternative fuels in cement kilns is a trend in the world. However, replacing fossil fuels like coal with different alternative fuels will give various impacts on the overall kiln process due to the fuel characteristics. Hence, it is important to know to what extent the fossil fuels can be replaced by different alternative fuels without severely changing process conditions, product quality or emissions. In the present study, a mass and energy balance for the combustion of dif...

  9. Process for capturing CO2 arising from the calcination of the CaCO3 used in cement manufacture.

    Science.gov (United States)

    Rodríguez, N; Alonso, M; Grasa, G; Abanades, J Carlos

    2008-09-15

    This paper outlines a new CaCO3 calcination method for producing a stream of CO2 (suitable for permanent geological storage after purification and compression). The process is based on the use of very hot CaO particles (T >1000 degrees C) to transfer heat from a circulating fluidized bed combustor (CFBC) to a calciner (fluidized with CO2 and/or steam). Since the fluidized bed combustor and calciner have separate atmospheres, the CO2 resulting from the decomposition of CaCO3 can be captured, while the CO2 generated in the combustion of the fuel in air is emitted to the atmosphere. We demonstrate that with this system it is possible to reduce the CO2 emissions of a cement plant by around 60%. Furthermore, since the key pieces of equipment are similar to the commercial CFBCs used in power generation plants, it is possible to establish the additional investment required for the system and to estimate the cost per ton of CO2 avoided for this process to be about 19 $/tCO2 avoided.

  10. The Added Value of the Project Selection Process

    Directory of Open Access Journals (Sweden)

    Adel Oueslati

    2016-06-01

    Full Text Available The project selection process comes in the first stage of the overall project management life cycle. It does have a very important impact on organization success. The present paper provides defi nitions of the basic concepts and tools related to the project selection process. It aims to stress the added value of this process for the entire organization success. The mastery of the project selection process is the right way for any organization to ensure that it will do the right project with the right resources at the right time and within the right priorities

  11. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll

    2013-01-01

    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone...... that raw meal could be used as a sorbent for the easy integration of the carbonate looping process into the cement pyro process for reducing CO2 emissions from the cement production process....

  12. PART II. HYDRATED CEMENTS

    Directory of Open Access Journals (Sweden)

    Milan Drabik

    2014-09-01

    Full Text Available Essential focus of the study has been to acquire thermoanalytical events, incl. enthalpies of decompositions - ΔH, of technological materials based on two types of Portland cements. The values of thermoanalytical events and also ΔH of probes of technological compositions, if related with the data of a choice of minerals of calcium-silicate-sulfate-aluminate hydrates, served as a valued input for the assessment of phases present and phase changes due to the topical hydraulic processes. The results indicate mainly the effects of "standard humidity" or "wet storage" of the entire hydration/hydraulic treatment, but also the presence of cement residues alongside calcium-silicate-sulfate-aluminate hydrates (during the tested period of treatment. "A diluting" effect of unhydrated cement residues upon the values of decomposition enthalpies in the studied multiphase system is postulated and discussed

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

    Science.gov (United States)

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

    2015-12-01

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

  14. Thoughts on the Current Cement Industry Development

    Institute of Scientific and Technical Information of China (English)

    Gan Zhihe

    2003-01-01

    According to the analysis of cement capacity andits relations with macro economy running index, the mainreasons for the present rapid development of cement capacityare the rapid development of economy and the shot up ofwhole society fixed asset investment. According to the presentspeed of economy development, cement still enjoys a po-tential increase, So here has not been an overall excessivepopularity of cement industry. The best way to prevent lowlevel repeated construction is to promote the development ofnew dry- process cement as well as try to get rid of blindness.

  15. The application of soft sensors in the pulp and paper and cement manufacturing sectors for process and energy performance improvement : opportunity analysis and technology assessment

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, M. [Effective Assets Inc., Ottawa, ON (Canada); Amazouz, M.; Platon, R. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

    2005-06-01

    Information from process experts and operators, research and development experts and sensors and control systems developers and providers is presented in order to help with the development and implementation of soft sensor technology. A soft sensor is the correlation from various raw data sources to create a new source of relevant information. Soft sensor technology is a useful tool in reducing energy consumption, operating costs, environmental impact and in improving final product quality. This report presents an introduction to soft sensor technology with reference to the need for soft sensors; first principal models; statistical based models; black box models; key success factors for a soft sensor project; benefits and drawbacks of soft sensor technology; and barriers to implementation of soft sensors. It discusses the state of the art in soft sensor research and development and industrial applications including design techniques and commercial software tools. Potential applications of soft sensors in the pulp and paper industry were discussed with reference to chemical pulping; mechanical pulping; newsprint and papermaking; and current applications of sensors in pulp and paper in Canada. Potential applications of soft sensors in the cement industry were also discussed. A survey was also conducted to obtain the opinions of industry experts, such as developers, suppliers and end-users of soft sensor applications. Interview notes were included in annex form. Key areas of future research and development include development of multi-grade models; development of adaptive models able to cope with production changes and shutdowns; increasing the awareness of plant managers and operators; development of user-friendly software; and recommendations on future work. 26 refs., 3 tabs., 6 figs., 2 appendices.

  16. Process development status report for advanced manufacturing projects

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, J.R.; Homan, D.A.

    1990-03-30

    This is the final status report for the approved Advanced Manufacturing Projects for FY 1989. Five of the projects were begun in FY 1987, one in FY 1988, and one in FY 1989. The approved projects cover technology areas in welding, explosive material processing and evaluation, ion implantation, and automated manufacturing. It is expected that the successful completion of these projects well result in improved quality and/or reduced cost for components produced by Mound. Those projects not brought to completion will be continued under Process development in FY 1990.

  17. PRINCIPLES OF RE-ENGINEERING METHODOLOGY FOR TECHNOLOGICAL PROCESS IN PROCESSING OF RAW MATERIAL COMPONENTS WHILE PRODUCING CEMENT AND SILICATE PRODUCTS

    Directory of Open Access Journals (Sweden)

    I. A. Busel

    2014-01-01

    necessity to modernize technological equipment used for grinding raw material components with the purpose to improve efficiency and quality, power- and resource saving. The possibility of using various grinding aids that permit to increase grinding productivity is shown in the paper. The paper studies an automation concept of the control system which used for grinding process of mineral raw material. A conceptual model for complexation of various methods grinding aids has been proposed in the paper. The paper presents methodological principles for simulation of technological process used for processing of mineral raw material while producing cement and silicate products. The parameters which are to be controlled and which are necessary for development of computer simulations of technological grinding process have been determined in the paper. The paper justifies an application of imitation simulation for creation of computer models. Methodology for imitation simulation of the technological process has been studied in the paper. The paper confirms the possibility to use analytical and probability methods. Imitation simulations of a grinding mill operation have been developed on the basis of experimental data and probability functions. The possibility of controlling technological process of raw material grinding has been demonstrated in the paper.While implementing the proposed complex of organizational and technical recommendations it is possible to increase grinding productivity up to 30-50 % and significantly reduce и существенно снизить energy consumption for mineral raw material grinding during production of cement and silicate products. The combined reengineering methodology for grinding process including all the mentioned intensification methods substantially increases quality of final products and reduces its self-cost that will favour its compatibility and attractiveness for consumers.

  18. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  19. Structure and properties of selected cemented carbides and cermets covered with TiN/(Ti,Al,SiN/TiN coatings obtained by the cathodic arc evaporation process

    Directory of Open Access Journals (Sweden)

    Leszek A. Dobrzañski

    2005-06-01

    Full Text Available This study presents the results of microstructural examinations, mechanical tests and service performance tests carried out on thin TiN/(Ti,Al,SiN/TiN wear resistance coatings obtained by the CAE process on cermet and cemented carbide substrates. Microstructural examinations of the applied coatings and the substrate were made with an OPTON DSM 940 SEM and a LEICA MEF4A light microscope. Adhesion of the coatings on cemented carbides and cermets was measured using the scratch test. The cutting properties of the materials were determined from service tests in which continuous machining of C45E steel was carried out. The hardness of the substrate and the microhardness of the coatings were determined with a DUH 202 SHIMADZU ultra microhardness tester with a load of 70 mN. Roughness tests were also carried out before applying the coatings and after the PVD process. Cutting tests confirmed the advantages of the TiN/(Ti,Al,SiN/TiN type coatings obtained using the PVD method in the CAE mode on cemented carbides and cermets, as a material that undergoes very low abrasive, thermal and adhesion wear. These coatings extend tool life compared to commercially available uncoated tools with single and multi-layer coatings deposited using PVD/CVD methods.

  20. Alternative Fuels in Cement Production

    DEFF Research Database (Denmark)

    Larsen, Morten Boberg

    for the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability...

  1. US cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  2. Lunar cement

    Science.gov (United States)

    Agosto, William N.

    1992-01-01

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

  3. The Use of Project Time Management Processes and the Schedule Performance of Construction Projects in Mexico

    Directory of Open Access Journals (Sweden)

    Rómel G. Solís-Carcaño

    2015-01-01

    Full Text Available Delays have been frequently reported as the cause of several conflicts that affect the different parties involved in construction projects. Project Time Management (PTM includes a number of planning and controlling processes that are recommended for complying with requirements related to project time. The study reported in this paper aimed at assessing the use of PTM processes and its relation with project schedule performance (i.e., timely completion. Seven PTM processes and seventy-seven tasks associated with them were identified from the literature that is globally relevant to project management. The study included the assessment of fourteen school construction projects executed by a public agency in the Yucatan Peninsula, Mexico. These projects were monitored during the construction phase in order to measure two different variables: the use of processes related to PTM (i.e., schedule planning and controlling processes and the project schedule performance. For each of these projects a Use Index was obtained for assessing the first variable, while the Schedule Performance Index and the Schedule Variance were computed to assess the second one. The results demonstrated there is statistical dependence between these two variables. Most of the projects that attained timely completion also made a greater use of the PTM processes.

  4. Software Defined Common Processing System (SDCPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coherent Logix, Incorporated proposes the Software Defined Common Processing System (SDCPS) program to facilitate the development of a Software Defined Radio...

  5. Friction Stir Processing of Cast Superalloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

  6. Software Defined Common Processing System (SDCPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Coherent Logix, Incorporated (CLX) proposes the development of a Software Defined Common Processing System (SDCPS) that leverages the inherent advantages of an...

  7. Software Project Management A Process-Driven Approach

    CERN Document Server

    Ahmed, Ashfaque

    2011-01-01

    To build reliable, industry-applicable software products, large-scale software project groups must continuously improve software engineering processes to increase product quality, facilitate cost reductions, and adhere to tight schedules. Emphasizing the critical components of successful large-scale software projects, Software Project Management: A Process-Driven Approach discusses human resources, software engineering, and technology to a level that exceeds most university-level courses on the subject. The book is organized into five parts. Part I defines project management with information o

  8. BUSINESS PROCESS MODELLING FOR PROJECTS COSTS MANAGEMENT IN AN ORGANIZATION

    Directory of Open Access Journals (Sweden)

    PĂTRAŞCU AURELIA

    2014-05-01

    Full Text Available Using Information Technologies in organizations represents an evident progress for company, money economy, time economy and generates value for the organization. In this paper the author proposes to model the business processes for an organization that manages projects costs, because modelling is an important part of any software development process. Using software for projects costs management is essential because it allows the management of all operations according to the established parameters, the management of the projects groups, as well as the management of the projects and subprojects, at different complexity levels.

  9. Closed Loop Waste Processing Dryer (DRYER) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to develop a gravity-independent pasteurization and hot air drying process suitable for stabilization of ALS wet cabin waste,...

  10. Multicore Rad Hard Processing in Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro proposes to research and develop a high performance computing/processing platform for NASA space missions. Leveraging our previous work for both NASA and...

  11. Friction Stir Processing of Cast Superalloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort examines the feasibility of an innovative fabrication technology incorporating sand casting and friction stir processing (FSP) for producing...

  12. Sets of Reports and Articles Regarding Cement Wastes Forms Containing Alpha Emitters that are Potentially Useful for Development of Russian Federation Waste Treatment Processes for Solidification of Weapons Plutonium MOX Fuel Fabrication Wastes for

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, L J

    2003-06-12

    This is a set of nine reports and articles that were kindly provided by Dr. Christine A. Langton from the Savannah River Site (SRS) to L. J. Jardine LLNL in June 2003. The reports discuss cement waste forms and primarily focus on gas generation in cement waste forms from alpha particle decays. However other items such as various cement compositions, cement product performance test results and some cement process parameters are also included. This set of documents was put into this Lawrence Livermore National Laboratory (LLNL) releasable report for the sole purpose to provide a set of documents to Russian technical experts now beginning to study cement waste treatment processes for wastes from an excess weapons plutonium MOX fuel fabrication facility. The intent is to provide these reports for use at a US RF Experts Technical Meeting on: the Management of Wastes from MOX Fuel Fabrication Facilities, in Moscow July 9-11, 2003. The Russian experts should find these reports to be very useful for their technical and economic feasibility studies and the supporting R&D activities required to develop acceptable waste treatment processes for use in Russia as part of the ongoing Joint US RF Plutonium Disposition Activities.

  13. The Process to Estimate Economical Benefits of Six Sigma Projects

    Directory of Open Access Journals (Sweden)

    Jan Kosina

    2013-07-01

    Full Text Available This paper seeks to define the process for the continuous evaluation of the financial benefits during Six Sigma project life time. The financial criteria are critical success factors of a Six Sigma project. The process has been developed as part of the six sigma project monitoring in order to estimate proper allocation of the resources taking in account the expected project benefits as well as evaluationof real achievements. The evaluation of the finacial benefits based on the quality costs is not sufficient in the real life and has to be accomplished with key financial performance indicators of the business to visualize the results. The evaluation based on the savings seems to be too difficult especially for green belts. The early involvement of the finance department in the project definition as well as ongoing evaluation is key. The defined process has been applied to real business enviroment.

  14. Novel Manufacturing Process for Unique Mixed Carbide Refractory Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR Phase I project will establish the feasibility of an innovative manufacturing process to fabricate a range of unique hafnium/silicon based carbide...

  15. In-Process Monitoring of Additive Manufacturing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The key innovation in this project is the implementation of an Imaging Fourier Transform Spectrometer (IFTS) for in situ metal additive manufacturing process...

  16. Risk Factors in ERP Implementation Projects for Process Oriented

    Directory of Open Access Journals (Sweden)

    Andrzej Partyka

    2009-09-01

    Full Text Available This paper present review and analysis of risk factors, which could affect successful implementation of ERP system, for project performed in project oriented organizations. Presented risk breakdown structure and the list of common risk factors, are well-suited for ERP implementation projects. Considered risk categories allow for complex risk analysis. Additionally, mapping of risk importance for particular implementation phases is presented. Making presented model an important input for project risk management process, especially for the beginning phases which require identification of risk factors.

  17. The Role of Demonstration Projects in Construction innovation processes

    DEFF Research Database (Denmark)

    Clausen, Lennie

    1999-01-01

    The article is describing the methodology of a case-study approach to the investigation of demonstration projects and their impact on the development of process and product innovations in the construction industry.......The article is describing the methodology of a case-study approach to the investigation of demonstration projects and their impact on the development of process and product innovations in the construction industry....

  18. A Systematic Approach to Modelling Change Processes in Construction Projects

    Directory of Open Access Journals (Sweden)

    Ibrahim Motawa

    2012-11-01

    Full Text Available Modelling change processes within construction projects isessential to implement changes efficiently. Incomplete informationon the project variables at the early stages of projects leads toinadequate knowledge of future states and imprecision arisingfrom ambiguity in project parameters. This lack of knowledge isconsidered among the main source of changes in construction.Change identification and evaluation, in addition to predictingits impacts on project parameters, can help in minimising thedisruptive effects of changes. This paper presents a systematicapproach to modelling change process within construction projectsthat helps improve change identification and evaluation. Theapproach represents the key decisions required to implementchanges. The requirements of an effective change processare presented first. The variables defined for efficient changeassessment and diagnosis are then presented. Assessmentof construction changes requires an analysis for the projectcharacteristics that lead to change and also analysis of therelationship between the change causes and effects. The paperconcludes that, at the early stages of a project, projects with a highlikelihood of change occurrence should have a control mechanismover the project characteristics that have high influence on theproject. It also concludes, for the relationship between changecauses and effects, the multiple causes of change should bemodelled in a way to enable evaluating the change effects moreaccurately. The proposed approach is the framework for tacklingsuch conclusions and can be used for evaluating change casesdepending on the available information at the early stages ofconstruction projects.

  19. Motion State of Fuel within Shell in Projection Acceleration Process

    Directory of Open Access Journals (Sweden)

    Qi Zhang

    2003-07-01

    Full Text Available The fuel-air explosive (FAE warheads are charged with the liquid-solid mixture fuel. The fuel is different 'om conventional solid explosives in physical and mechanical properties. The mass centre of the charged fuel changes during projecting the projectile. In this study, a method to calculate the mass centre change of the charged fuel is suggested and the  influence of this change on the projectile motion state in the projection process is discussed. The results show that in projection, the fuel mass centre varies with the projection acceleration and the deformation characteristics of the mixture fuel. The higher is the acceleration, the larger is the displacement of the mass centre. This displacement also increases with the compressibility of the fuel. It constitutes an influence on the state of motion for the whole projectile in the projection process, whose calculation approach is also proposed. The result provides a theoretical basis for the design of the FAE weapons.

  20. Process simulation and parametric modeling for strategic project management

    CERN Document Server

    Morales, Peter J

    2013-01-01

    Process Simulation and Parametric Modeling for Strategic Project Management will offer CIOs, CTOs and Software Development Managers, IT Graduate Students an introduction to a set of technologies that will help them understand how to better plan software development projects, manage risk and have better insight into the complexities of the software development process.A novel methodology will be introduced that allows a software development manager to better plan and access risks in the early planning of a project.  By providing a better model for early software development estimation and softw

  1. Effect of aluminium phosphate as admixture on oxychloride cement

    Indian Academy of Sciences (India)

    M P S Chandrawat; R N Yadav

    2000-02-01

    The effect of admixing of aluminium phosphate on oxychloride cement in the matrix has been investigated. It is shown that aluminium phosphate retards the setting process of the cement and improves water-tightness.

  2. Project Interface Requirements Process Including Shuttle Lessons Learned

    Science.gov (United States)

    Bauch, Garland T.

    2010-01-01

    Most failures occur at interfaces between organizations and hardware. Processing interface requirements at the start of a project life cycle will reduce the likelihood of costly interface changes/failures later. This can be done by adding Interface Control Documents (ICDs) to the Project top level drawing tree, providing technical direction to the Projects for interface requirements, and by funding the interface requirements function directly from the Project Manager's office. The interface requirements function within the Project Systems Engineering and Integration (SE&I) Office would work in-line with the project element design engineers early in the life cycle to enhance communications and negotiate technical issues between the elements. This function would work as the technical arm of the Project Manager to help ensure that the Project cost, schedule, and risk objectives can be met during the Life Cycle. Some ICD Lessons Learned during the Space Shuttle Program (SSP) Life Cycle will include the use of hardware interface photos in the ICD, progressive life cycle design certification by analysis, test, & operations experience, assigning interface design engineers to Element Interface (EI) and Project technical panels, and linking interface design drawings with project build drawings

  3. Substantial global carbon uptake by cement carbonation

    Science.gov (United States)

    Xi, Fengming; Davis, Steven J.; Ciais, Philippe; Crawford-Brown, Douglas; Guan, Dabo; Pade, Claus; Shi, Tiemao; Syddall, Mark; Lv, Jie; Ji, Lanzhu; Bing, Longfei; Wang, Jiaoyue; Wei, Wei; Yang, Keun-Hyeok; Lagerblad, Björn; Galan, Isabel; Andrade, Carmen; Zhang, Ying; Liu, Zhu

    2016-12-01

    Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2 emissions from all industrial process and fossil-fuel combustion in 2013. Considerable attention has been paid to quantifying these industrial process emissions from cement production, but the natural reversal of the process--carbonation--has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondary use of concrete waste to estimate regional and global CO2 uptake between 1930 and 2013 using an analytical model describing carbonation chemistry. We find that carbonation of cement materials over their life cycle represents a large and growing net sink of CO2, increasing from 0.10 GtC yr-1 in 1998 to 0.25 GtC yr-1 in 2013. In total, we estimate that a cumulative amount of 4.5 GtC has been sequestered in carbonating cement materials from 1930 to 2013, offsetting 43% of the CO2 emissions from production of cement over the same period, not including emissions associated with fossil use during cement production. We conclude that carbonation of cement products represents a substantial carbon sink that is not currently considered in emissions inventories.

  4. A project management focused framework for assuring quality work processes

    Energy Technology Data Exchange (ETDEWEB)

    Gamsby, S.O.; Mize, J.D. [Allied Signal, Inc., Albuquerque, NM (United States). Federal Mfg. and Technologies; Reid, R.A. [New Mexico Univ., Albuquerque, NM (United States)

    1996-10-01

    Federal Manufacturing & Technologies/New Mexico (FM&T/NM) of AlliedSignal is an organization of approximately 300 associates providing operations support, engineering, and other technical services for DOE, New Mexico`s National Laboratories, etc. Work performed is primarily project-oriented and ranges from executing a major long-term contract for retrofitting and maintaining a large fleet of escort vehicles to creating a single, small, prototype electronic device for measuring radiation in a unique environment. FM&T/NM is functionally organized and operates in a classic matrix format with functional departments providing personnel with technical expertise, necessary physical resources, and administrative support to several project-based groups. Like most matrix-based organizations that provide support to diverse customers, FM&T/NM has encountered problems that occur when a group of project managers is expected to work together in using and scheduling a shared set of limited resources for the good of the organization as a whole. The framework for managing projects that we present focuses on developing, understanding, and managing the relationships between the functional organization structure, the system of work processes, and the management of projects. FM&T/NM retains its functional structure which primarily assigns personnel to work processes. The evolving role of the process leader focuses primarily on designing, managing, and improving the process, and the interactions among the subprocesses. The project manager is responsible for (1) translating customer requirements into product specifications, (2) determining the sequence of activities needed to meet project goals, (3) scheduling the required work processes, (4) monitoring project progress, (5) providing liaison between the customer and process leaders, and (6) having the desired product and/or service delivered to a satisfied customer in a timely manner.

  5. Project INOVEMAR: Innovation in Sea Produce Processment

    Directory of Open Access Journals (Sweden)

    Maria Alberta Araújo

    2014-06-01

    Following information conveyed by Docapesca, the less valued species captured in the region are different mackerel species, Atlantic horse mackerel, pout, octopus and mullet. Mackerel and Atlantic horse mackerel, due to their high subcutaneous fat were used for smoking and for the production of canned smoked fillets and patés, with different sauces.The smoking process included: washing fresh fish, 30 minutes immersion in a 80º brine, followed by dripping and drying for 48h. Smoking was carried out at 70ºC during 3h, with a final stage at 90ºC. Several paté formulations were developed with mackerel and atlantic horse mackerel, with different types and quantities of ingredients and flavourings to obtain different products. Special attention was paid to the amounts of thickeners and emulsifiers to attain a pleasant spread ability. All preparations were sterilized for 15 minutes at 121ºC. A sensory panel with 10 judges and a consumer panel with 59 consumers were used to test the developed products. The 59 consumers (17-25 years of age classified smoked products as moderately pleasant. 82% of the consumers tested expressed willingness to purchase the product. In what concerns patés, sensory judges as well as consumers rated the majority of products as very good in the several parameters under evaluation, indication that there is a great potential for these type of commodities. Several fish species are being studied for pre-cooking conservation. In all the cases studied, typical Portuguese cuisine is being used, followed by rapid chilling and packing with modified atmospheres. Preparations, preservation and subsequent consumption are being carried out at the school's canteen. The results obtained until now show that low commercial valued species can be used with success, providing some culinary expertise is added. This is a very important aspect since, transferring this technology to industry, may lead to the development of new products and help an easy flow of

  6. Evaluation of a lime-mediated sewage sludge stabilisation process. Product characterisation and technological validation for its use in the cement industry.

    Science.gov (United States)

    Rodríguez, N Husillos; Granados, R J; Blanco-Varela, M T; Cortina, J L; Martínez-Ramírez, S; Marsal, M; Guillem, M; Puig, J; Fos, C; Larrotcha, E; Flores, J

    2012-03-01

    This paper describes an industrial process for stabilising sewage sludge (SS) with lime and evaluates the viability of the stabilised product, denominated Neutral, as a raw material for the cement industry. Lime not only stabilised the sludge, raised the temperature of the mix to 80-100°C, furthering water evaporation, portlandite formation and the partial oxidation of the organic matter present in the sludge. Process mass and energy balances were determined. Neutral, a white powder consisting of portlandite (49.8%), calcite (16.6%), inorganic oxides (13.4%) and organic matter and moisture (20.2%), proved to be technologically apt for inclusion as a component in cement raw mixes. In this study, it was used instead of limestone in raw mixes clinkerised at 1400, 1450 and 1500°C. These raw meals exhibited greater reactivity at high temperatures than the limestone product and their calcination at 1500°C yielded clinker containing over 75% calcium silicates, the key phases in Portland clinker. Finally, the two types of raw meal (Neutral and limestone) were observed to exhibit similar mineralogy and crystal size and distribution.

  7. Hidration kinetics study of tlie mixed cements

    OpenAIRE

    Duque Fernández, Gabriel . L; Díaz Quintanilla, David; Zapata Sierra, Manuel; Rubio Frías, Ester

    1993-01-01

    A study of the hydration process of cements with 10% and 20% addition of a tuff from "Las Carolinas" quarry (Cienfuegos, Cuba) by different methods was done. The results obtained by different methods showed a good agreement. It was proved an increment of the hydration products, an acceleration of alite hydration and a swelling of the fixed water in mixed cements. The resistance of the cement with 10% addition is similar to that of the pure cement for ages of 28 days, whereas with 20% addition...

  8. Cement Formation:A Success Story in a Black Box: High Temperature Phase Formation of Portland Cement Clinker

    OpenAIRE

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledgeabout the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in ...

  9. 77 FR 47337 - Project-Level Predecisional Administrative Review Process

    Science.gov (United States)

    2012-08-08

    ... Forest Service 36 CFR Part 218 RIN 0596-AD07 Project-Level Predecisional Administrative Review Process... establishes the sole process by which the public may file objections seeking predecisional administrative... Rangeland Renewable Resources Planning Act of 1974, and documented with a Record of Decision (ROD)...

  10. VCM Process Design: An ABET 2000 Fully Compliant Project

    Science.gov (United States)

    Benyahia, Farid

    2005-01-01

    A long experience in undergraduate vinyl chloride monomer (VCM) process design projects is shared in this paper. The VCM process design is shown to be fully compliant with ABET 2000 criteria by virtue of its abundance in chemical engineering principles, integration of interpersonal and interdisciplinary skills in design, safety, economics, and…

  11. TECHNIQUES FOR MANAGING PROJECTS RISK IN CAPITAL BUDGETING PROCESS

    Directory of Open Access Journals (Sweden)

    Sinisa Bogdan

    2010-12-01

    Full Text Available The paper examines capital budgeting process and techniques of risk analysis in the process of selecting optimal project. Corporate manager in process of capital budgeting uses numerous techniques some of them are based on intuition and experience of manager, and some of them are analytic based on sensitive, scenario, decision tree and Monte Carlo method. All methods are used to determinate and to predict risk influence on the projects. Article deals with analytical techniques and real problems that can arise in capital budgeting process. Trough case study in article we analyzed risks that may emerge from different techniques. Conclusion that emerges from analyzing different methods of risk techniques is that only with right combination of these techniques corporate manager could decide correctly to choose optimal capital project.

  12. The HRA/Solarium Project: Processing of Widely Varying High- and Medium-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Willems, M.; Luycx, P.; Gilis, R.; Belgoprocess; Renard, Cl.; Reyniers, H.; Cuchet, J. M.

    2003-02-26

    Starting in 2003, Belgoprocess will proceed with the treatment and conditioning of some 200 m{sup 3} of widely varying high- and medium-level waste from earlier research and development work, to meet standard acceptance criteria for later disposal. The gross volume of primary and secondary packages amounts to 2,600 m{sup 3}. The waste has been kept in decay storage for up to 30 years. The project was started in 1997. Operation of the various processing facilities will take 7-8 years. The overall volume of conditioned waste will be of the order of 800 m{sup 3}. All conditioned waste will be stored in appropriate storage facilities onsite. At present (November, 2002), a new processing facility has been constructed, the functional tests of the equipment have been performed and the startup phase has been started. Several cells of the Pamela vitrification facility onsite will be adapted for the treatment of high-level and highly a-contaminated waste; low-level a/a waste will be treated in the existing facility for super compaction and conditioning by embedding into cement (CILVA). The bulk of these waste, of which 95% are solids, the remainder consisting of mainly solidified liquids, have been produced between 1967 and 1988. They originate from various research programs and reactor operation at the Belgian nuclear energy research centre SCK CEN, isotope production, decontamination and dismantling operations.

  13. Application of X-ray Computed Tomography in Characterization Microstrueture Changes of Cement Pastes in Carbonation Process

    Institute of Scientific and Technical Information of China (English)

    HAN Jiande; SUN Wei; PAN Ganghua; WANG Caihui; RONG Hui

    2012-01-01

    The microstructure characteristics and meso-defect volume changes of hardened cement paste before and after carbonation were investigated by three-dimensional (3D) X-ray computed tomography (XCT),where three types water-to-cement ratio of 0.53,0.35 and 0.23 were considered.The high-resolution 3D images of microstructure and filtered defects were reconstructed by an XCT VG Studio MAX 2.0 software.The mesodefect volume fractions and size distribution were analyzed based on 3D images through add-on modules of 3D defect analysis.The 3D meso-defects volume fractions before carbonation were 0.79%,0.38% and 0.05%corresponding to w/c ratio=0.53,0.35 and 0.23,respectively.The 3D meso-defects volume fractions after carbonation were 2.44%,0.91% and 0.14% corresponding to w/c ratio=0.53,0.35 and 0.23,respectively.The experimental results suggest that 3D meso-defects volume fractions after carbonation for above three w/c ratio increased significantly.At the same time,meso-cracks distribution of the carbonation shrinkage and gray values changes of the different w/c ratio and carbonation reactions were also investigated.

  14. Understanding and Managing Process Interaction in IS Development Projects

    DEFF Research Database (Denmark)

    Bygstad, Bendik; Nielsen, Peter Axel

    2005-01-01

    -technical innovation in a situation where the organisational change process and the IS development process are parallel but incongruent. We also argue that iterative software engineering frameworks are well structured to support process interaction. Finally, we advocate that the IS project manager needs to manage......Increasingly, information systems must be developed and implemented as a part of business change. This is a challenge for the IS project manager, since business change and information systems development usually are performed as separate processes. Thus, there is a need to understand and manage...... development approach. The concept of process interaction enabled us to understand critical events in the case, in particular those that were important for the mutual adaptation between the information system and the organisation. We conclude that process interaction is needed to facilitate socio...

  15. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  16. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  17. Application of Liner Cementation Technology in Wenchuan Earthquake Fault Scientific Drilling Project%汶川地震断裂带科学钻探项目尾管固井技术的应用

    Institute of Scientific and Technical Information of China (English)

    樊腊生; 张伟; 李前贵; 李旭东; 赵远刚

    2012-01-01

      介绍了汶川地震断裂带科学钻探项目钻探施工过程中尾管固井技术的应用情况。针对该项目钻探施工的复杂地层条件,研发了适合于破碎地层和小套管间隙的无接箍尾管固井技术,关键技术包括尾管管柱设计、尾管下入及钻柱分离技术和施工工艺、适合于破碎地层和小套管间隙条件的尾管固井浆液设计和施工工艺。采用研发成功的尾管固井技术,在该项目的二号孔和三号孔中共进行了4次下尾管作业,均获得了成功。%  This article introduces the liner cementation technology and its application in Wenchuan earthquake scientific drilling project.According to the conditions of complex formation in this drilling project, liner cementation technology which is suitable for broken formation and small annulus between borehole and casing string, has been developed.The key points of this technology include liner string design and installation and cementing slurry design and construction.This tech-nology has been successfully used in 4 liner cementation operations.

  18. Frozen delivery of brushite calcium phosphate cements.

    Science.gov (United States)

    Grover, Liam M; Hofmann, Michael P; Gbureck, Uwe; Kumarasami, Balamurgan; Barralet, Jake E

    2008-11-01

    Calcium phosphate cements typically harden following the combination of a calcium phosphate powder component with an aqueous solution to form a matrix consisting of hydroxyapatite or brushite. The mixing process can be very important to the mechanical properties exhibited by cement materials and consequently when used clinically, since they are usually hand-mixed their mechanical properties are prone to operator-induced variability. It is possible to reduce this variability by pre-mixing the cement, e.g. by replacing the aqueous liquid component with non-reactive glycerol. Here, for the first time, we report the formation of three different pre-mixed brushite cement formulations formed by freezing the cement pastes following combination of the powder and liquid components. When frozen and stored at -80 degrees C or less, significant degradation in compression strength did not occur for the duration of the study (28 days). Interestingly, in the case of the brushite cement formed from the combination of beta-tricalcium phosphate with 2 M orthophosphoric acid solution, freezing the cement paste had the effect of increasing mean compressive strength fivefold (from 4 to 20 MPa). The increase in compression strength was accompanied by a reduction in the setting rate of the cement. As no differences in porosity or degree of reaction were observed, strength improvement was attributed to a modification of crystal morphology and a reduction in damage caused to the cement matrix during manipulation.

  19. Distributed Processing of Projections of Large Datasets: A Preliminary Study

    Science.gov (United States)

    Maddox, Brian G.

    2004-01-01

    Modern information needs have resulted in very large amounts of data being used in geographic information systems. Problems arise when trying to project these data in a reasonable amount of time and accuracy, however. Current single-threaded methods can suffer from two problems: fast projection with poor accuracy, or accurate projection with long processing time. A possible solution may be to combine accurate interpolation methods and distributed processing algorithms to quickly and accurately convert digital geospatial data between coordinate systems. Modern technology has made it possible to construct systems, such as Beowulf clusters, for a low cost and provide access to supercomputer-class technology. Combining these techniques may result in the ability to use large amounts of geographic data in time-critical situations.

  20. Process competencies in a problem and project based learning environment

    DEFF Research Database (Denmark)

    Du, Xiangyun; Kolmos, Anette

    2006-01-01

    Future engineers are not only required to master technological competencies concerning solving problems, producing and innovating technology, they are also expected to have capabilities of cooperation, communication, and project management in diverse social context, which are referred to as process...... competencies. Consequently, engineering education is facing challenges regarding how to facilitate students with scientific-technological competencies as well as process competencies. Problem based learning (PBL) as an educational model is regarded as an effective example regarding preparing students...... with the expected professional competencies. Based on the educational practice of PBL Aalborg Model, which is characterized by problem-orientation, project-organization and team work, this paper examines the process of developing process competencies through studying engineering in a PBL environment from...

  1. Post-project geomorphic assessment of a large process-based river restoration project

    Science.gov (United States)

    Erwin, Susannah O.; Schmidt, John C.; Allred, Tyler M.

    2016-10-01

    This study describes channel changes following completion of the Provo River Restoration Project (PRRP), the largest stream restoration project in Utah and one of the largest projects in the United States in which a gravel-bed river was fully reconstructed. We summarize project objectives and the design process, and we analyze monitoring data collected during the first 7 years after project completion. Post-project channel adjustment during the study period included two phases: (i) an initial phase of rapid, but small-scale, adjustment during the first years after stream flow was introduced to the newly constructed channel and (ii) a subsequent period of more gradual topographic adjustment and channel migration. Analysis of aerial imagery and ground-survey data demonstrate that the channel has been more dynamic in the downstream 4 km where a local source contributes a significant annual supply of bed material. Here, the channel migrates and exhibits channel adjustments that are more consistent with project objectives. The upstream 12 km of the PRRP are sediment starved, the channel has been laterally stable, and this condition may not be consistent with large-scale project objectives.

  2. Evaluating the Project based Organizational Teaching-Learning Process

    Directory of Open Access Journals (Sweden)

    S. Justus

    2013-06-01

    Full Text Available Organizational Training and Learning are among the 22 key process areas in CMM. These two processes are subject for improvement based on its framework and execution. In this paper, we have worked on project-based frameworks for organizational training and learning and have attempted to validate them in the software developmental organizations and in an institution teaching software engineering.The empirical validation is carried out with those case studies and significant results are obtained in assessing the improvement in the two process areas. Moreover, this work is also extended to accommodate improvement in the regular conventional OTL processes.

  3. 78 FR 18481 - Project-Level Predecisional Administrative Review Process

    Science.gov (United States)

    2013-03-27

    ... controversial or the analysis documents are complex. Response: Neither the administrative appeal process under... basic information about the project, and does not allow the public to review and comment on the requisite environmental analysis and proposed alternatives. Precluding public comments on the...

  4. Examining Perceptions of the Science Fair Project: Content or Process?

    Science.gov (United States)

    Watson, Jinx Stapleton

    2003-01-01

    Discusses student research, information literacy and research skills, and the role of inquiry in the research process. Presents a case study of a middle school science fair project that examined what students should accomplish in their research and what the role of stakeholders is, including teachers, parents, and school library media specialists.…

  5. 33 CFR 385.11 - Implementation process for projects.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Implementation process for projects. 385.11 Section 385.11 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE PROGRAMMATIC REGULATIONS FOR THE COMPREHENSIVE EVERGLADES RESTORATION PLAN...

  6. Asphalt cement poisoning

    Science.gov (United States)

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  7. 小议桥梁工程中水泥混凝土技术性能及其应用%Technical Performance of Cement Concrete and Its Application in the Bridge Project

    Institute of Scientific and Technical Information of China (English)

    宫北辰

    2012-01-01

    在桥梁工程中应用最广泛的是普通混凝土:以水泥为胶凝材料,以砂,石为骨料,加水拌制成的水泥混凝土.普通混凝土normal concrete一般指以水泥为主要胶凝材料,与水、砂、石子,必要时掺入化学外加剂和矿物掺合料,按适当比例配合,经过均匀搅拌、密实成型及养护硬化而成的人造石材.因此,水泥混凝土技术性能控制对工程质量保证至关重要.%What is the most widely used in bridge engineering is the normal concrete which takes the cement as the cementitious material, the sand and stone as the aggregate, and then add water to mix. Normal concrete is generally refers to the artificial stone with cement which is the main cementitious material, water, sand and gravel, including chemical admixtures and mineral admixtures if necessary, with an appropriate proportion, uniform mixing, forming dense and conservation rigidification. Therefore, the technical performance control of cement concrete is essential to project quality assurance.

  8. PROFILING AND THE STUDENT PROJECT PEER APPRAISAL PROCESS

    OpenAIRE

    Rodley C. Pineda; Bonita B. Barger; Linda D. Lerner

    2011-01-01

    Past research on team formation and composition reveals that team member attributes play a role in how students perceive each others’ contributions to a team project. Can attribute-based profiling be used during the peer appraisal process so that a holistic-based assessment tool can still provide meaningful feedback to the student being rated? Our study shows that students can develop a profile of the ideal team member at the start of the project that is consistent with their overall assess...

  9. Green Project System Design of Machine Process Factory

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    As the specialty of the product and the dim conscio us ness of environmental protection, the status of dirty, chaos and difference is l ong-term existed in the machine process factory. It seriously affects workers' work and living environment, and restricts the total level of the environment p rotection in our country. The project is the fatal scientific research task of H enan province in 2001. As the members' endeavor of task group, we have finished the total plan of green project system and some other ...

  10. Isothermal Calorimetry Study of Blended Cements and its Application in Numerical Simulations

    NARCIS (Netherlands)

    Xiong, X.; Van Breugel, K.

    2001-01-01

    Apparent activation energy (E) is generally used to consider the effect of temperature on the kinetics of cement hydration in the numerical simulation of cement hydration processes. This paper deals with an experimental study on the kinetics of Portland cement and blast furnace slag cement using iso

  11. Emission and distribution of PCDD/Fs and CBzs from two co-processing RDF cement plants in China.

    Science.gov (United States)

    Chen, Tong; Zhan, Ming-Xiu; Lin, Xiao-Qing; Li, Ye-Qing; Zhang, Jiang; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-06-01

    An analysis of the emission and distribution characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and chlorobenzenes (CBzs) from two cement kilns (CK1 and CK2) is done. Six measurements in CK1 showed an increase of PCDD/F emission from 76 to 97 pg I-TEQ/Nm(3) after feeding 10 ton/h RDF (refuse derived fuel). For CK2, the effect of increasing the RDF substitution rates from 0 to 21 t/h on the emission of PCDD/Fs was investigated. The correlation analysis indicated that replacing parts of the conventional fuel with RDF could not increase the emission of PCDD/Fs. Furthermore, the gas/particle partitions of PCDD/Fs and CBzs in stack gas were investigated, indicating that PCDD/Fs and CBzs were more associated in gas phase, especially for the lower chlorinated ones. Moreover, the bag filter fly ash was characterized by its particle distribution, XRD- and EDS-analysis. Additionally, the level of PCDD/Fs in outflowing fly ash escalates for smaller particle size. In order to evaluate the environmental effect on inhabitants, the levels of PCDD/Fs were also determined in samples of ambient air collected in the vicinity of CK2 (~200 m).

  12. Energetically Modified Cement (EMC) - Performance Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Ronin, Vladimir; Elfgren, Lennart [Luleaa Univ. of Technology (Sweden). Centre for High Performance Cement

    2003-03-01

    Energetically Modified Cements, EMC, made of intensively milled cement (50%) and fillers (50%) of quartz or fly ash have been compared to blends of Ordinary Portland Cement, OPC, and fillers. The EMCs have better properties than other blends and are comparable to unblended OPC. This remarkable fact can probably be explained as follows. The grinding process reduces the size of both cement grains and fillers. This combined with the creation of micro defects gives the ground cement a very high degree of hydration. The increased early hydration and a better distribution of hydration products results in an extensive pore size refinement of the hardened binder. This pore size refinement leads to a favorably reduced permeability and diffusivity and very good mechanical properties.

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

    Science.gov (United States)

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

    2014-09-01

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

  14. Process Intensification via Membrane Reactors, the DEMCAMER Project

    Directory of Open Access Journals (Sweden)

    Fausto Gallucci

    2016-05-01

    Full Text Available This paper reports the findings of a FP7 project (DEMCAMER that developed materials (catalysts and membranes and new processes for four industrially relevant reaction processes. In this project, active, stable, and selective catalysts were developed for the reaction systems of interest and their production scaled up to kg scale (TRL5 (TRL: Technology Readiness Level. Simultaneously, new membranes for gas separation were developed; in particular, dense supported thin palladium-based membranes for hydrogen separation from reactive mixtures. These membranes were successfully scaled up to TRL4 and used in various lab-scale reactors for water gas shift (WGS, using both packed bed and fluidized bed reactors, and Fischer-Tropsch (FTS using packed bed reactors and in prototype reactors for WGS and FTS. Mixed ionic-electronic conducting membranes in capillary form were also developed for high temperature oxygen separation from air. These membranes can be used for both Autothermal Reforming (ATR and Oxidative Coupling of Methane (OCM reaction systems to increase the efficiency and the yield of the processes. The production of these membranes was scaled up to TRL3–4. The project also developed adequate sealing techniques to be able to integrate the different membranes in lab-scale and prototype reactors.

  15. UMTRA Ground Water Project management action process document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    A critical U.S. Department of Energy (DOE) mission is to plan, implement, and complete DOE Environmental Restoration (ER) programs at facilities that were operated by or in support of the former Atomic Energy Commission (AEC). These facilities include the 24 inactive processing sites the Uranium Mill Tailings Radiation Control Act (UMTRCA) (42 USC Section 7901 et seq.) identified as Title I sites, which had operated from the late 1940s through the 1970s. In UMTRCA, Congress acknowledged the potentially harmful health effects associated with uranium mill tailings and directed the DOE to stabilize, dispose of, and control the tailings in a safe and environmentally sound manner. The UMTRA Surface Project deals with buildings, tailings, and contaminated soils at the processing sites and any associated vicinity properties (VP). Surface remediation at the processing sites will be completed in 1997 when the Naturita, Colorado, site is scheduled to be finished. The UMTRA Ground Water Project was authorized in an amendment to the UMTRCA (42 USC Section 7922(a)), when Congress directed DOE to comply with U.S. Environmental Protection Agency (EPA) ground water standards. The UMTRA Ground Water Project addresses any contamination derived from the milling operation that is determined to be present at levels above the EPA standards.

  16. Implementing a Process for Integration Research: Ecosystem Services Project, Australia

    Directory of Open Access Journals (Sweden)

    Steven J. Cork

    2005-01-01

    Full Text Available This paper reports on the design and implementation of a multi-phase interactive process among a set of scientists, policy makers, land managers, and community representatives, so as to facilitate communication, mutual understanding, and participative decision making. This was part of the Ecosystem Services Project in Australia. The project sought to broaden public understanding about the natural ecosystems in Australia. The study reported here pertains to one of the project sites--the Goulburn Broken catchment, a highly productive agricultural watershed in the south-east of Australia. The paper demonstrates how, starting from a condition of diversity of ideas and interests among the participants, systematic dialogue and mutual learning could be generated, leading to identification of options for more sustainable land management practices. The concept of “ecosystem services” was used as an integrative tool across disciplines and community perspectives. The concept of scenarios was used to encourage future-focussed thinking among the participants. The idea of “stakeholder jury” was used to promote deliberation. A process of multi-criteria evaluation was used to facilitate convergence of viewpoints, through informed trade-offs and compromises. This experience led to the development of a process for integration research, which helped in harmonising across diverse understandings and values in a transparent and structured manner.

  17. Through Lean Manufacturing Techniques Improvement InProduction of Cement Plant

    Directory of Open Access Journals (Sweden)

    Udai Singh Chouhan

    2016-07-01

    Full Text Available The production of cement is a process industry which is distinct from manufacturing and the main objective here is to apply lean manufacturing technique to the eradicate waste to the processes and parameters which are common between process and discrete manufacturing. Lean signifies a major advance over traditional mass production methods. Value stream mapping is used first to identify different waste present in the current state. This paper will describe work undertaken investigating the application of lean thinking to a continuous production environment, in this instance exemplified by the cement industry. Implementation of lean helps many organizations to improve their productivity and efficiency Cement plays a vital role in economic development of any country. Having more than a hundred and fifty years history, it has been used extensively in construction of anything, from a small building to a mammoth multi-purpose project. The need for improving the efficiency of the cement production line is widely acknowledged in order to reduce the downtime rates, and satisfy high levels of market demand where the demand for cement is mostly second substance behind water. This paper articulates a methodology for data collection, knowledge extraction, model creation and experimentation that combines the use of process mapping, computational simulation. A detailed description of each step of the process is given and is illustrated by results from a case study undertaken during the research. This paper describes work undertaken to implement lean practices in the continuous process sector as represented by cement production. One of the major barriers to lean implementation is providing evidence of its potential benefit to end-users. This work aims to overcome this obstacle by producing a tool which can be used to easily visualize the benefits of adopting lean practices without requiring disruption to the production environment

  18. Analysis on Impacts and Co-Abatement Effects of Implementing the Low Carb on Cement Standard

    Institute of Scientific and Technical Information of China (English)

    PANG Jun; SHI Yuan-Chang; FENG Xiang-Zhao; WU Shi-Yu; SUN Wen-Long

    2014-01-01

    Based on the MAP-CGE model, this paper simulated the impacts on the output, energy consumption and pollutant emissions of different cement production processes when implementing a low carbon cement standard in China. It also calculated the impacts on the marginal abatement cost and equilibrium price of the cement industry, and analyzed the co-abatement effects of different pollutants. The results showed that implementing the low carbon cement standard will be beneficial in promoting an upgrading of cement production processes, and strengthening the energy conservation and emission reduction in the cement industry. If there is no change in the existing technology, the cement industry will reduce SO2 emissions by 1.17 kg and NOx emissions by 4.44 kg per ton of CO2 emission reduction. Implementing low carbon cement standard can also promote NOx abatement in the cement industry. However, the cement industry will bear the abatement costs, and their equilibrium price will increase slightly.

  19. Understanding and Managing Process Interaction in IS Development Projects

    DEFF Research Database (Denmark)

    Bygstad, Bendik; Nielsen, Peter Axel

    2012-01-01

    critical events in the case, what led to the events, and what the consequences are. We discuss the implications for information systems research and in particular we discuss the contribution to project management of iterative and incremental software development.......Software-based information systems must be developed and implemented as a part of business change. This is a major challenge, since business change and the development of software-based information systems usually are performed in separate processes. Thus, there is a need to understand and manage...... the relationship between these two kinds of processes. In this paper we draw on a longitudinal case study. We suggest a framework to analyze the case as interaction between software development processes and organizational change processes. In the analysis we find that the framework enables us to understand...

  20. Aligning BIM with FM: streamlining the process for future projects

    Directory of Open Access Journals (Sweden)

    Colleen Kasprzak

    2015-10-01

    Full Text Available A study performed by the National Institute of Standards and Technology (NIST, USA in 2004 found that owners account for approximately $10.6 billion of the $15.8 billion total inadequate interoperability costs of U.S. capital facility projects in 2002. Because of these inefficiency costs, it becomes vital that information produced during the design and construction phases of a project be transferred into operations with maximum leverage to the end users. However, very few owners have defined these informational needs or developed an integration strategy into existing maintenance management systems. To increase operational efficiency, an organization must first develop an understanding of their operating systems, as well as identify how Building Information Modeling (BIM will add value to their daily tasks. The Pennsylvania State University (PSU has a unique opportunity to diversely implement BIM processes because not only does the University act as an owner, but also as designer and construction manager on the majority of projects. The struggle that PSU faces is one that is unique only to owners with a large, existing, multifaceted building inventory. This paper outlines the current initiative by the Office of Physical Plant (OPP, the asset manager at PSU, to develop an information exchange framework between BIM and FM applications to be used internally. As a result of this research, PSU has been able to define owner operational requirements for future projects and develop a flexible integration framework to support additional BIM tasks and information exchanges.

  1. Aligning BIM with FM: streamlining the process for future projects

    Directory of Open Access Journals (Sweden)

    Colleen Kasprzak

    2012-12-01

    Full Text Available A study performed by the National Institute of Standards and Technology (NIST, USA in 2004 found that owners account for approximately $10.6 billion of the $15.8 billion total inadequate interoperability costs of U.S. capital facility projects in 2002. Because of these inefficiency costs, it becomes vital that information produced during the design and construction phases of a project be transferred into operations with maximum leverage to the end users. However, very few owners have defined these informational needs or developed an integration strategy into existing maintenance management systems. To increase operational efficiency, an organization must first develop an understanding of their operating systems, as well as identify how Building Information Modeling (BIM will add value to their daily tasks. The Pennsylvania State University (PSU has a unique opportunity to diversely implement BIM processes because not only does the University act as an owner, but also as designer and construction manager on the majority of projects. The struggle that PSU faces is one that is unique only to owners with a large, existing, multifaceted building inventory. This paper outlines the current initiative by the Office of Physical Plant (OPP, the asset manager at PSU, to develop an information exchange framework between BIM and FM applications to be used internally. As a result of this research, PSU has been able to define owner operational requirements for future projects and develop a flexible integration framework to support additional BIM tasks and information exchanges.

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

    Energy Technology Data Exchange (ETDEWEB)

    Collier, N.C., E-mail: nick.collier@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Milestone, N.B. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Callaghan Innovation, 69 Gracefield Road, PO Box 31310, Lower Hutt 5040 (New Zealand); Gordon, L.E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); Geopolymer and Minerals Processing Group, Department of Chemical and Biomolecular Engineering, University of Melbourne, Parkville, Victoria 3010 (Australia); Ko, S.-C. [Holcim Technology Ltd, Hagenholzstrasse 85, CH-8050 Zurich (Switzerland)

    2014-09-15

    Highlights: • We investigate a supersulfated cement for use as a nuclear waste encapsulant. • High powder fineness requires a high water content to satisfy flow requirements. • Heat generation during hydration is similar to a control cement paste. • Typical hydration products are formed resulting in a high potential for waste ion immobilisation. • Paste pH and aluminium corrosion is less than in a control cement paste. - Abstract: 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.

  3. Strength improvement of fibre cement product

    Directory of Open Access Journals (Sweden)

    Waranya Sonphuak

    2013-10-01

    Full Text Available This paper presents a methodology to improve the strength or the Modulus of Rupture (MOR of fibre cement. The Six Sigma approach with the DMAIC steps was applied to a case study company. This research started from defining problem, setting the project objective and the project scope. Next, the measurement system was analyzed and the process map was set up. The potential factors of the problem was then determined. Due to there were many factors that affect the MOR, the Cause and Effect Matrix and the Failure Mode and Effect Analysis technique were then used to reduce the number of factors to be studied further. Next, three process factors, which were the pulp slurry freeness, the film-layer thickness, and the pressure step, were optimized using the results from the Box-Behnken experimental design. Other 13 remaining factors were improved by creating or revising the standard work instructions and training the operators. After that, the statistical process control and the control plan were set up to control the production processes. After improvement, the process capability index (Ppk significantly increased from 0.26 to 1.35.

  4. Finite element modelling of rheological and penetration characteristics of curing PMMA bone cement in total hip replacement

    OpenAIRE

    2006-01-01

    This thesis is concerned with the study of the rheological properties of PMMA bone cement that is used as a grout for bone and prosthesis in THR and TKR Interdigitation of bone cement through porous cancellous bone depends on the rheological characteristics of bone cement and porosity of the cancellous bone. The rheological characteristics of the bone cement are thus an important factor effecting the optimum penetration of bone cement through cancellous bone. In this project the rheologic...

  5. Secondary fuels and raw materials in the Spanish cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Gordobil, J.C.U.; Guede, Elena [Cementos Lemona s.a. (Spain)

    1997-03-01

    The growing environmental and energy concern are having an impact on the Spanish cement industry. This article describes the impact on waste management, the operation of cement kilns and the possibility for recycling. Current projects and future prospects are described. (UK)

  6. Consideration on the tender offer of overseas cement general contract project%海外水泥总承包工程投标报价的思考浅析

    Institute of Scientific and Technical Information of China (English)

    潘轶

    2015-01-01

    In tender offer of overseas projects, how to obtain competitive advantage under the premise of conrolling and avoiding risk is the key to profit. Combined with practical experiences, from the aspects of biding doucuments reading, field reconnaissance and prepa?ration of tender documents, matters needing attention of tender offer in overseas cement general contract project are introduced in detail.%在海外工程投标报价中,如何在取得竞争优势的同时,又能控制和规避风险,这是项目获利的关键之一.结合具体实践经验,从招标文件的研读和现场踏勘及投标文件的准备方面详细介绍了海外水泥总包工程投标报价的注意事项.

  7. Synthesis of pure Portland cement phases

    DEFF Research Database (Denmark)

    Wesselsky, Andreas; Jensen, Ole Mejlhede

    2009-01-01

    Pure phases commonly found in Portland cement clinkers are often used to test cement hydration behaviour in simplified experimental conditions. The synthesis of these phases is covered in this paper, starting with a description of phase relations and possible polymorphs of the four main phases...... in Portland cement, i.e. tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium alumino ferrite. Details of the The process of solid state synthesis are is described in general including practical advice on equipment and techniques. Finally In addition, some exemplary mix compositions...

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

    Science.gov (United States)

    Hall, Alex Keith

    2011-12-01

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

  9. A research paper of `the basic sciences of the radioactive waste treatment` (Jul. 28,29, 1994) and `Interface and surface science of solid waste processing and disposal -differences between cement and bentonite` (Dec. 14, 1995)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    This report contains copies of OHP at the meetings of which discussions were centered upon the points of sameness and difference between cement and bentonite. There are sixteen papers, eleven in the first meeting and five in the second one. The following studies were read as under, on the first meeting, the role of retardation effect on the safety of high level atomic waste stratum processing, determination of colloid particle diameters by use of fieldflow fractionation, adsorption behavior of uranium, into black mica in granite, masstransfer mechanism of Cs and Se in the compression-bentonite, delay mechanism under conditions of mineral alteration, effects of humus on the behavior of radionuclides in stratum, formation of actinoids - humic acid complex and its effect on adsorption behavior, characteristic properties of water in bentonite, measurement of solubility of uranium and niobium, behavior of colloidal Am in the bentonite, illite - water system, effects of aging deterioration of bentonite on diffusion of nuclides, and on the second meeting, a view of cement materials, chemical behavior and long period stability of cement - relating to Atkinson model -, the present conditions of studies about sorption in cement, chemical properties of pore water in bentonite and interaction of bentonite and nuclides in solid - liquid interface. (S.Y.)

  10. Holocene cemented beach deposits in Belize

    Science.gov (United States)

    Gischler, Eberhard; Lomando, Anthony J.

    1997-06-01

    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.

  11. Statistical Study on Cement-Soil Mixture Strength

    Institute of Scientific and Technical Information of China (English)

    YU Zhiqiang; CAO Yonghua; YAN Shuwang

    2005-01-01

    This paper presents an investigation on strength of cement deep mixing (CDM) mixture. Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, statistical analysis is made on the increment law of the strength of cement-soil mixture with different amount of cement, and strengths under different working conditions are compared. It is found that the amount of cement in the cement-soil mixture is closely related to the unconfined compressive strength of the mixture. At the age of 90 d,the unconfined compressive strength of the cement-soil mixture increased by 0.054 Mpa-0.124 Mpa with each cement increasing 10 kg/m3 in the cement-soil mixture, averagely increased by 0.085 Mpa, while that at the age of 120 d increased by 11% in comparison.The quality of the cement-soil mixture should be comprehensively evaluated in accordance with the trimmed average of strength, coefficient of variation and rock quality designation (RQD) indicators of sampling ratio.

  12. Extension of moment projection method to the fragmentation process

    Science.gov (United States)

    Wu, Shaohua; Yapp, Edward K. Y.; Akroyd, Jethro; Mosbach, Sebastian; Xu, Rong; Yang, Wenming; Kraft, Markus

    2017-04-01

    The method of moments is a simple but efficient method of solving the population balance equation which describes particle dynamics. Recently, the moment projection method (MPM) was proposed and validated for particle inception, coagulation, growth and, more importantly, shrinkage; here the method is extended to include the fragmentation process. The performance of MPM is tested for 13 different test cases for different fragmentation kernels, fragment distribution functions and initial conditions. Comparisons are made with the quadrature method of moments (QMOM), hybrid method of moments (HMOM) and a high-precision stochastic solution calculated using the established direct simulation algorithm (DSA) and advantages of MPM are drawn.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-03-01

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

  14. The Iron Project:. Radiative Atomic Processes in Astrophysics

    Science.gov (United States)

    Nahar, Sultana N.

    2011-06-01

    Astronomical objects, such as, stars, galaxies, blackhole environments, etc are studied through their spectra produced by various atomic processes in their plasmas. The positions, shifts, and strengths of the spectral lines provide information on physical processes with elements in all ionization states, and various diagnostics for temperature, density, distance, etc of these objects. With presence of a radiative source, such as a star, the astrophysical plasma is dominated by radiative atomic processes such as photoionization, electron-ion recombination, bound-bound transitions or photo-excitations and de-excitations. The relevant atomic parameters, such as photoionization cross sections, electron-ion recombination rate coefficients, oscillator strengths, radiative transition rates, rates for dielectronic satellite lines etc are needed to be highly accurate for precise diagnostics of physical conditions as well as accurate modeling, such as, for opacities of astrophysical plasmas. for opacities of astrophysical plasmas. This report illustrates detailed features of radiative atomic processes obtained from accurate ab initio methods of the latest developments in theoretical quantum mechanical calculations, especially under the international collaborations known as the Iron Project (IP) and the Opacity Project (OP). These projects aim in accurate study of radiative and collsional atomic processes of all astrophysically abundant atoms and ions, from hydrogen to nickel, and calculate stellar opacities and have resulted in a large number of atomic parameters for photoionization and radiative transition probabilities. The unified method, which is an extension of the OP and the IP, is a self-consistent treatment for the total electron-ion recombination and photoionization. It incorporates both the radiative and the dielectronic recombination processes and provides total recombination rates and level-specific recombination rates for hundreds of levels for a wide range of

  15. Cement stratigraphy: Image probes of cathodoluminescent facies.

    OpenAIRE

    Vuillemin, Aurèle; Ndiaye, Mapathe; Martini, Rossana; Davaud, Eric Jean

    2011-01-01

    Cement stratigraphy of carbonates aims to establish the chronology of processes involved in the rock diagenesis. Regional cement stratigraphy allows correlations and understanding of the petrological heterogeneities in reservoirs and aquifers, but is a long and rigorous approach. This article exposes a methodology of image analysis that facilitates the spatial correlation of diagenetic events in carbonate rocks. Based on the statistical comparison of signals extracted from the red spectrum em...

  16. Data Processing Center of Radioastron Project: 3 years of operation.

    Science.gov (United States)

    Shatskaya, Marina

    ASC DATA PROCESSING CENTER (DPC) of Radioastron Project is a fail-safe complex centralized system of interconnected software/ hardware components along with organizational procedures. Tasks facing of the scientific data processing center are organization of service information exchange, collection of scientific data, storage of all of scientific data, data science oriented processing. DPC takes part in the informational exchange with two tracking stations in Pushchino (Russia) and Green Bank (USA), about 30 ground telescopes, ballistic center, tracking headquarters and session scheduling center. Enormous flows of information go to Astro Space Center. For the inquiring of enormous data volumes we develop specialized network infrastructure, Internet channels and storage. The computer complex has been designed at the Astro Space Center (ASC) of Lebedev Physical Institute and includes: - 800 TB on-line storage, - 2000 TB hard drive archive, - backup system on magnetic tapes (2000 TB); - 24 TB redundant storage at Pushchino Radio Astronomy Observatory; - Web and FTP servers, - DPC management and data transmission networks. The structure and functions of ASC Data Processing Center are fully adequate to the data processing requirements of the Radioastron Mission and has been successfully confirmed during Fringe Search, Early Science Program and first year of Key Science Program.

  17. Tritium Facilities Modernization and Consolidation Project Process Waste Assessment (Project S-7726)

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, R.H. [Westinghouse Savannah River Company, AIKEN, SC (United States); Oji, L.N.

    1997-11-14

    Under the Tritium Facility Modernization {ampersand} Consolidation (TFM{ampersand}C) Project (S-7726) at the Savannah River Site (SS), all tritium processing operations in Building 232-H, with the exception of extraction and obsolete/abandoned systems, will be reestablished in Building 233-H. These operations include hydrogen isotopic separation, loading and unloading of tritium shipping and storage containers, tritium recovery from zeolite beds, and stripping of nitrogen flush gas to remove tritium prior to stack discharge. The scope of the TFM{ampersand}C Project also provides for a new replacement R&D tritium test manifold in 233-H, upgrading of the 233- H Purge Stripper and 233-H/234-H building HVAC, a new 234-H motor control center equipment building and relocating 232-H Materials Test Facility metallurgical laboratories (met labs), flow tester and life storage program environment chambers to 234-H.

  18. Examination of solidified and stabilized matrices as a result of solidification and stabilization process of arseniccontaining sludge with portland cement and lime

    Directory of Open Access Journals (Sweden)

    Tanapon Phenrat

    2004-02-01

    Full Text Available By solidification and stabilization (S/S with Portland cement and lime, it is possible to reduce arsenic concentration in leachate of the arsenic-containing sludge from arsenic removal process by coagulation with ferric chloride. From the initial arsenic concentration in leachate of unsolidified /unstabilized sludge which was around 20.75 mg/L, the arsenic concentrations in leachate of solidified/stabilized waste were reduced to 0.3, 0.58, 1.09, and 1.85 mg/L for the waste-to-binder ratios of 0.15, 0.25, 0.5, and 1, respectively, due tothe formation of insoluble calcium-arsenic compounds. To be more cost effective for the future, alternative uses of these S/S products were also assessed by measurement of compressive strength of the mortar specimens. It was found that the compressive strengths of these matrices were from 28 ksc to 461 ksc. In conclusion, considering compressive strength and leachability of the solidified matrices, some of these solidified/ stabilized products have potential to serve as an interlocking concrete paving block.

  19. Quantification of the Reduced Environmental Impacts with Use of Co-Processing in Cement Kilns in India

    OpenAIRE

    Ankur Tiwary; Garima Sharma; Gupta, P K

    2014-01-01

    Coupled with resource conservation and reduced carbon emissions, co-processing technology is a preferable alternative for sound and environmental friendly waste disposal over incinerators & non-scientific methods. It is not only solution to the waste disposal menace, but also reduces burden on secured landfills & TSDFs. Apart from using energy and material value of wastes, co-processing not only fixes the inorganic content of the wastes within the clinker, but also, it destroys the wa...

  20. China’s Hongqi Group Invests 500 Million Yuan in Guixi Copper Processing Project

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>China’s Hongqi Group recently signed an agreement with Guixi municipality to invest 500 million yuan in developing the copper processing project in Guixi.It is reported that this is the seveth copper processing project with

  1. Chemical and Physical Reactions of Wellbore Cement under CO2 Storage Conditions: Effects of Cement Additives

    Science.gov (United States)

    Kutchko, B. G.; Strazisar, B. R.; Huerta, N.; Lowry, G. V.; Dzombak, D. A.; Thaulow, N.

    2008-12-01

    Sequestration of CO2 into geologic formations requires long-term storage and low leakage rates to be effective. Active and abandoned wells in candidate storage formations must be evaluated as potential leakage points. Wellbore integrity is an important part of an overall integrated assessment program being developed at NETL to assess potential risks at CO2 storage sites. Such a program is needed for ongoing policy and regulatory decisions for geologic carbon sequestration. The permeability and integrity of the cement in the well is a primary factor affecting its ability to prevent leakage. Cement must be able to maintain low permeability over lengthy exposure to reservoir conditions in a CO2 injection and storage scenario. Although it is known that cement may be altered by exposure to CO2, the results of ongoing research indicate that cement curing conditions, fluid properties, and cement additives play a significant role in the rate of alteration and reaction. The objective of this study is to improve understanding of the factors affecting wellbore cement integrity for large-scale geologic carbon sequestration projects. Due to the high frequency use of additives (pozzolan) in wellbore cement, it is also essential to understand the reaction of these cement-pozzolan systems upon exposure to CO2 under sequestration conditions (15.5 MPa and 50°C). Laboratory experiments were performed to determine the physical and chemical changes, as well as the rate of alteration of commonly used pozzolan-cement systems under simulated sequestration reservoir conditions, including both supercritical CO2 and CO2-saturated brine. The rate of alteration of the cement-pozzolan systems is considerably faster than with neat cement. However, the alteration of physical properties is much less significant with the pozzolanic blends. Permeability of a carbonated pozzolanic cement paste remains sufficiently small to block significant vertical migration of CO2 in a wellbore. All of the

  2. The Setting Chemistry of Glass Ionomer Cement

    Institute of Scientific and Technical Information of China (English)

    CHENG Hanting; LIU Hanxing; ZHANG Guoqing

    2005-01-01

    The setting chemistry of glass ionomer cement was investigated by using mechanical determination of compressive strength at predetermined intervals, and measurement of structure changes of corresponding fracture sample by means of IR spectra and differential scanning calorimetry ( DSC). Zinc polycarboxylate cement was used as a comparison sample. The compressive strength of glass ionomer cement (GIC) increases with aging. IR spectra and DSC of corresponding fracture sample show the structure changes of the matrix and interface layer comprising of silica gel during the predetermined intervals studied, however, no significant changes occur in the zinc polycarxyolate cement. Hence the structure changes of the matrix and/or interface layer are responsible for compressive strength increasing with aging. The structure changes include the crosslink density, the ratio of complex form to ionic form, the content ratio of Al-PAA to Ca-PAA, the forming and mauring process of the interface layer comprising of silica gel.

  3. An Overview of the JPSS Ground Project Algorithm Integration Process

    Science.gov (United States)

    Vicente, G. A.; Williams, R.; Dorman, T. J.; Williamson, R. C.; Shaw, F. J.; Thomas, W. M.; Hung, L.; Griffin, A.; Meade, P.; Steadley, R. S.; Cember, R. P.

    2015-12-01

    The smooth transition, implementation and operationalization of scientific software's from the National Oceanic and Atmospheric Administration (NOAA) development teams to the Join Polar Satellite System (JPSS) Ground Segment requires a variety of experiences and expertise. This task has been accomplished by a dedicated group of scientist and engineers working in close collaboration with the NOAA Satellite and Information Services (NESDIS) Center for Satellite Applications and Research (STAR) science teams for the JPSS/Suomi-NPOES Preparatory Project (S-NPP) Advanced Technology Microwave Sounder (ATMS), Cross-track Infrared Sounder (CrIS), Visible Infrared Imaging Radiometer Suite (VIIRS) and Ozone Mapping and Profiler Suite (OMPS) instruments. The presentation purpose is to describe the JPSS project process for algorithm implementation from the very early delivering stages by the science teams to the full operationalization into the Interface Processing Segment (IDPS), the processing system that provides Environmental Data Records (EDR's) to NOAA. Special focus is given to the NASA Data Products Engineering and Services (DPES) Algorithm Integration Team (AIT) functional and regression test activities. In the functional testing phase, the AIT uses one or a few specific chunks of data (granules) selected by the NOAA STAR Calibration and Validation (cal/val) Teams to demonstrate that a small change in the code performs properly and does not disrupt the rest of the algorithm chain. In the regression testing phase, the modified code is placed into to the Government Resources for Algorithm Verification, Integration, Test and Evaluation (GRAVITE) Algorithm Development Area (ADA), a simulated and smaller version of the operational IDPS. Baseline files are swapped out, not edited and the whole code package runs in one full orbit of Science Data Records (SDR's) using Calibration Look Up Tables (Cal LUT's) for the time of the orbit. The purpose of the regression test is to

  4. Social Psychology of Facts, Processes and Projects. Object and Time

    Directory of Open Access Journals (Sweden)

    Gil, Adriana

    2006-05-01

    Full Text Available A dimension that must be considered, in the reflection that social sciences offer to society, is temporality. I would like to highlight the implicit idea of temporality within the different forms of psychosocial knowledge. In this article I propose that the different types of social psychology orientations can be situated on an axis of temporality which makes a distinction between those orientations that assume that the object of social knowledge is a fact (that is an object without temporality, being change a mere succession of independent facts, and those orientations that assume that their object is a process (that is an object in movement or perpetual change. Finally, I propose a potential social psychology of projects as an essential part of my own concept of what social psychology is

  5. Carbonate Looping for De-Carbonization of Cement Plants

    OpenAIRE

    2011-01-01

    Cement industry is one of the largest emitter of CO2 other than power generation plants, which includes the emissions from combustion of fuel and also from calcination of limestone for clinker production. In order to reduce CO2 emissions from the cement industry an effective an economically feasible technology is to be developed. The carbonate looping process is a promising technology, which is particularly suitable for the cement industry as limestone could be used for capture and release of...

  6. Cemented Volcanic Soils, Martian Spectra and Implications for the Martian Climate

    Science.gov (United States)

    Bishop, J. L.; Schiffman, P.; Drief, A.; Southard, R. J.

    2004-03-01

    Cemented volcanic crusts are studied to learn about their composition, formation processes, and implications for climate interactions with the surface on Mars. Such carbonate, sulfate and opal crusts may be present in cemented soil units on Mars.

  7. Study on the hardening mechanism of cement asphalt binder

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The hydration and hardening mechanism of cement asphalt binder(CAB) was studied.The early hydration process,hydration products and paste microstructure of CAB made by Portland cement and anionic asphalt emulsion were investigated by calorimetry,X-ray diffraction,and environmental scanning electron microscopy.The early hydration process of CAB can be characterized as 5 stages similar to those of Portland cement.There is no chemical reaction detected between cement and asphalt,hence no new hydration products other than those of Portland cement are produced.The hardening of CAB begins with the hydration of cement.When the hydration of cement comes into the acceleration period and its exothermic rate comes to the maximum,the coalescence of asphalt particles in asphalt emulsion is triggered.In the hardened system of CAB,it was found that the hydration products of cement form the skeleton and are covered by the continuous asphalt film.They formed an interpenetrating network system.The emulsifiers in the asphalt emulsion may retard the hydration process of cement.

  8. Development of a novel cement by conversion of hopeite in set zinc phosphate cement into biocompatible apatite.

    Science.gov (United States)

    Horiuchi, Shinya; Asaoka, Kenzo; Tanaka, Eiji

    2009-01-01

    Synthetic bone cement that has zinc oxide core particles covered with hydroxyapatite (HAP) was developed; that is, the conversion of hopeite, the traditional zinc phosphate cement, into HAP was attempted. Here, hopeite is the final product of the reaction between powders and trituration liquid of the traditional zinc phosphate cement. This cement may have many advantages not only in terms of biological functions but also the setting process of the traditional cement and the mechanical properties of the developed compact if the hopeite can be converted into calcium phosphate (CP). In this study, calcium nitrate solutions of various concentrations were used for the conversion of hopeite crystals into CP. The products after the solution treatment were analyzed by X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), and scanning electron microscope (SEM) observation. These results indicated that the converted scholzite crystals could be partially detected. Several types of set zinc phosphate cement with different P/L ratios were arranged. The surface products of the set cement after the solution treatment were analyzed by XRD. However, the crystal phase such as hopeite was not detected except for zinc oxide. The set cement, which was treated with the calcium nitrate solution, was immersed in simulated body fluid (SBF). HAP-like crystals on the set cement could be detected for the specimens immersed for 4 weeks. These findings suggested that the binding phase in the set cement could be converted into HAP by immersion in SBF.

  9. SODIUM CITRATE INFLUENCE ON FORMATION OF CEMENT STONE IN THE ALUMINOUS BINDER

    Directory of Open Access Journals (Sweden)

    S. N. Leonovich

    2016-01-01

    Full Text Available The paper deals with the effect of sodium citrate on the formation of a cement stone in the aluminous binder. Formation of cement stone framework in cement hydraulic binder is accompanied with complicated physical and chemical processes of interphase interactions and dispersion, these processes are predicated on qualitative and quantitative composition of the cement mortar, continuous changes in its properties from preparation stage till curing. Addition of sodium citrate to tempering water enhances hydration of both Portland cement and calcium aluminate cement. Process pertaining to an increase of cement hydration rate is considered as a consequence of destruction in surface formations and exclusion of damping effect in respect of hydration rate and hydrolysis of products resulted from interaction of clinker material with tempering. It has been established that sodium citrate makes it possible to control processes of hydration, hydrolysis, binding and curing for cement mass. High degree of hydration of aluminous cement in the presence of sodium citrate provides fast binding and curing of binder, low porosity and rather high compression breaking strength of cement stone for all curing stages. An increase in concentration of sodium citrate in cement mixture up to 10 % of the cement mass exerts an influence not only on the process of cement mortar liquefaction, reduction of time for cement mass setting and hardening but also increases compression strength of cement stone. An analysis of the structure for cleavage surface of cement stone gives ground to declare that the addition of sodium citrate provides cement stone sealing and reduces its water absorption.

  10. Calibration of stereo rigs based on the backward projection process

    Science.gov (United States)

    Gu, Feifei; Zhao, Hong; Ma, Yueyang; Bu, Penghui; Zhao, Zixin

    2016-08-01

    High-accuracy 3D measurement based on binocular vision system is heavily dependent on the accurate calibration of two rigidly-fixed cameras. In most traditional calibration methods, stereo parameters are iteratively optimized through the forward imaging process (FIP). However, the results can only guarantee the minimal 2D pixel errors, but not the minimal 3D reconstruction errors. To address this problem, a simple method to calibrate a stereo rig based on the backward projection process (BPP) is proposed. The position of a spatial point can be determined separately from each camera by planar constraints provided by the planar pattern target. Then combined with pre-defined spatial points, intrinsic and extrinsic parameters of the stereo-rig can be optimized by minimizing the total 3D errors of both left and right cameras. An extensive performance study for the method in the presence of image noise and lens distortions is implemented. Experiments conducted on synthetic and real data demonstrate the accuracy and robustness of the proposed method.

  11. Research of magnesium phosphosilicate cement

    Science.gov (United States)

    Ding, Zhu

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

  12. Design of Fit-for-Purpose Cement to Restore Cement-Caprock Seal Integrity

    Science.gov (United States)

    Provost, R.

    2015-12-01

    This project aims to study critical research needs in the area of rock-cement interfaces, with a special focus on crosscutting applications in the Wellbore Integrity Pillar of the SubTER initiative. This study will focus on design and test fit-for-purpose cement formulations. The goals of this project are as follows: 1) perform preliminary study of dispersing nanomaterial admixtures in Ordinary Portland Cement (OPC) mixes, 2) characterize the cement-rock interface, and 3) identify potential high-performance cement additives that can improve sorption behavior, chemical durability, bond strength, and interfacial fracture toughness, as appropriate to specific subsurface operational needs. The work presented here focuses on a study of cement-shale interfaces to better understand failure mechanisms, with particular attention to measuring bond strength at the cement-shale interface. Both experimental testing and computational modeling were conducted to determine the mechanical behavior at the interface representing the interaction of cement and shale of a typical wellbore environment. Cohesive zone elements are used in the finite element method to computationally simulate the interface of the cement and rock materials with varying properties. Understanding the bond strength and mechanical performance of the cement-formation interface is critical to wellbore applications such as sequestration, oil and gas production and exploration and nuclear waste disposal. Improved shear bond strength is an indication of the capability of the interface to ensure zonal isolation and prevent zonal communication, two crucial goals in preserving wellbore integrity. Understanding shear bond strength development and interface mechanics will provide an idea as to how the cement-formation interface can be altered under environmental changes (temperature, pressure, chemical degradation, etc.) so that the previously described objectives can be achieved. Sandia National Laboratories is a multi

  13. Case Study of the California Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

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

  14. Solidification of Spent Ion Exchange Resin Using ASC Cement

    Institute of Scientific and Technical Information of China (English)

    周耀中; 云桂春; 叶裕才

    2002-01-01

    Ion exchange resins (IERs) have been widely used in nuclear facilities. However, the spent radioactive IERs result in major quantities of low and intermediate level radioactive wastes. This article describes a laboratory experimental study on solidification processing of IERs using a new type of cement named ASC cement. The strength of the cementation matrix is in the range of 18-20 MPa (28 d); the loading of the spent IER in the cement-resin matrix is over 45% and leaching rates of 137Cs, 90Sr and 60Co are 7.92×10-5, 5.7×10-6, and 1.19×10-8 cm/d. The results show that ASC cement can be a preferable cementation material for immobilization of radioactive spent IER.

  15. Project Management, Critical Praxis, and Process-Oriented Approach to Teamwork

    Science.gov (United States)

    Ding, Huiling; Ding, Xin

    2008-01-01

    To help alleviate issues of free-riding and conflicts in team projects, this study proposes the systematic incorporation of project management methods to introduce a process-oriented approach to and a critical praxis in team projects. We examined how the systematic use of project management methods influenced students' performance in team…

  16. NASA Ocean Altimeter Pathfinder Project. Report 1; Data Processing Handbook

    Science.gov (United States)

    Koblinsky, C. J.; Beckley, Brian D.; Ray, Richard D.; Wang, Yan-Ming; Tsaoussi, Lucia; Brenner, Anita; Williamson, Ron

    1998-01-01

    The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-sedes data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. This report describes the processing schemes used to produce a consistent data set and two of the products derived f rom these data. Other reports have been produced that: a) describe the validation of these data sets against tide gauge measurements and b) evaluate the statistical properties of the data that are relevant to climate change. The use of satellite altimetry for earth observations was proposed in the early 1960s. The first successful space based radar altimeter experiment was flown on SkyLab in 1974. The first successful satellite radar altimeter was flown aboard the Geos-3 spacecraft between 1975 and 1978. While a useful data set was collected from this mission for geophysical studies, the noise in the radar measured and incomplete global coverage precluded ft from inclusion in the Ocean Altimeter Pathfinder program. This program initiated its analysis with the Seasat mission, which was the first satellite radar altimeter flown for oceanography.

  17. POZZOLAN AND CEMENTS WITH POZZOLAN

    OpenAIRE

    Hasan KAPLAN; Hanifi BİNİCİ

    1995-01-01

    Cement, one of the basic material of construction engineering, has an important place in view of strength and cost of structures. Cement consumption is increasing parallel to development of building construction sector. For cement producers, minimal cost is desired by using new and economical material sources. On the other hand, the controllers and contractors need cheaper, safer and higher strength materials. From this respect cement industry tends to use cement with pozzolan. In Türkiye, ce...

  18. Keynote presentation: Project Management, Technology and Evolving Work Processes

    DEFF Research Database (Denmark)

    Kampf, Constance Elizabeth

    Bridging the classroom and workplace is a challenge in the Project Management classroom because students rarely have the opportunity or the experience needed to head up large projects. So how can instructors present the opportunity to develop skills and gain experience needed to understand project...... management in a classroom setting? To begin to answer this question, the presentation describes three key strategies used in a Project Management course developed from a communications perspective in the International Bachelor Program in Marketing and Management Communication, Business & Social Sciences......, Aarhus University. First, this Project Management course involves continual, ongoing development through working with real clients. To learn about project management from a communications perspective, learners were asked to work in teams for project conception and planning. To communicate with the client...

  19. Investigating conceptual models for physical property couplings in solid solution models of cement

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Watson, Claire; Savage, David [Quintesssa Ltd., Henley-on-Thames (United Kingdom)

    2005-11-15

    The long-term behaviour of cementitious engineered barriers is an important process to consider when modelling the migration of radionuclides from a geological repository for nuclear waste. The modelling of cement is complicated by the fact that the cement is dominated by the behaviour of calcium silicate hydrate (CSH) gel which is a complex solid exhibiting incongruent dissolution behaviour. In this report, we have demonstrated the implementation of a solid-solution CSH gel model within a geochemical transport modelling framework using the Raiden computer code to investigate cement/concrete-groundwater interactions. The modelling conducted here shows that it is possible to couple various conceptual models for the evolution of physical properties of concrete with a solid solution model for cement degradation in a fully coupled geochemical transport model to describe the interaction of cement/concrete engineered barriers with groundwater. The results show that changes to the conceptual models and flow rates can give rise to very different evolutions. Most simulations were carried out at a reduced 'experimental' scale rather than full repository scale. The work has shown the possibility to investigate also the changing physical properties of degrading cement. To further develop the model more emphasis is needed on kinetics and the detailed development of a nearly clogged pore space. Modelling of the full repository scale could be another way forward to understand the behaviour of degrading concrete. A general conclusion is that the combined effects of chemical evolution and physical degradation should be analysed in performance assessments of cementitious repositories. Moreover, the project results will be used as one basis in coming reviews of SKB's safety assessments of repositories for spent fuel and low-and intermediate level waste.

  20. Coupled effect of cement hydration and temperature on hydraulic behavior of cemented tailings backfill

    Institute of Scientific and Technical Information of China (English)

    WU Di; CAI Si-jing

    2015-01-01

    Cemented tailings backfill (CTB) is made by mixing cement, tailings and water together, thus cement hydration and water seepage flow are the two crucial factors affecting the quality of CTB. Cement hydration process can release significant amount of heat to raise the temperature of CTB and in turn increase the rate of cement hydration. Meanwhile, the progress of cement hydration consumes water and produces hydration products to change the pore structures within CTB, which further influences the hydraulic behavior of CTB. In order to understand the hydraulic behavior of CTB, a numerical model was developed by coupling the hydraulic, thermal and hydration equations. This model was then implemented into COMSOL Multiphysics to simulate the evolutions of temperature and water seepage flow within CTB versus curing time. The predicted outcomes were compared with correspondent experimental results, proving the validity and availability of this model. By taking advantage of the validated model, effects of various initial CTB and curing temperatures, cement content, and CTB's geometric shapes on the hydraulic behavior of CTB were demonstrated numerically. The presented conclusions can contribute to preparing more environmentally friendly CTB structures.

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

    Science.gov (United States)

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

    2016-03-15

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

  2. Development of nanosilica bonded monetite cement from egg shells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: huanzhou@cczu.edu.cn [Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Luchini, Timothy J.F.; Boroujeni, Nariman Mansouri [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Agarwal, Anand K.; Goel, Vijay K. [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2015-05-01

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

  3. Hydration hardening process control of low alkalinity sulphoaluminate cement and its microstructure analysis%低碱硫铝酸盐水泥水化硬化历程调控及其微结构分析

    Institute of Scientific and Technical Information of China (English)

    周华新; 刘加平; 刘建忠

    2012-01-01

    By using borax as retarder to wrap the low alkalinity sulphoaluminate cement particle,the problem of excessive growth of cement hydration and condensation was effectively solved. By introducing the model of water molecules and smaller ion slow permeating through boric acid calcium wrapped layer, and combining with reducing the liquid concentration mechanism outside the boric acid calcium wrapped layer, the model of retardation and then early strength was established. Effect of borax and lithium compound on the setting time, hydration process, mechanical properties and microstructure of low alkalinity sulphoaluminate cement was studied. The results show that,the hydration exothermic chemical process and the condensation hardening process of low alkalinity sulphoaluminate cement can be controlled by appropriate amounts of borax and lithium compound. Borax only reduces the formation rate of hydration products while lithium only increases the formation rate of hydration products, both have no impact on type of hydration products. The composition of borax and lithium compound can optimize the microstructure of hardened slurry, by reducing the total porosity and average aperture of low alkalinity sulphoaluminate cement.%采用缓凝组分硼砂对低碱硫铝酸盐水泥颗粒实施有效包裹,解决了水化凝结速度过快的难题,引入水分子和较小的离子缓慢渗透通过硼酸钙包裹层模型,并结合降低硼酸钙包裹层外液相浓度机制,建立了先缓凝后早强模型.研究了硼砂、锂化合物对低碱硫铝酸盐水泥凝结时间、水化历程、力学性能及微观结构的影响.试验结果表明,可通过控制硼砂和锂化合物的掺量实现低碱硫铝酸盐水泥水化硬化历程的调控;硼砂仅降低了水化产物的生成速率,锂化合物仅提高了水化产物的生成速率,两者对水化产物种类无影响;硼砂和锂化合物的复合使用能降低总孔隙率和平均孔径,能明显优化硬化浆体微结构.

  4. WHITE CEMENT IN SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Y.C.P RAMANA BABU

    2013-04-01

    Full Text Available India is one among the fast developing countries in the world in the areas of Infrastructure. Now a day, Carbon monoxide (CO and carbon dioxide (CO2 are the temporary atmospheric pollutants in the environment chiefly emitted from the fuel burning vehicles and street lights which lead to global warming and pose a major threat tothe survival and sustainable development. This paper deals with the principal purpose of use of white cement in pavement design which will take care of the Green house gases (i.e., CO and CO2 and also saves lot of money in the long run process. A small amount of these gases in environment can cause major problems over time. Use of white cement in composite pavement design where there is heavy traffic loads are acting as well as number of vehicles are more such as junctions, bus stops, check posts etc., can perform better and acts asenvironment friendly. Its light colour reflects more than bituminous pavement so that it can be easily identified and avoid accidents to some extent. White cement helps to lower the average bus stop, junction temperature providing comfort to the people because it has high solar reflectance there by reducing “urban heat island” effect. In addition to this it has some more advantages which increase the sustainability, durability and workability of the pavements.

  5. Project B610 process control configuration acceptance test procedure

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, G.R.

    1994-09-20

    The purpose of this test is to verify the Westinghouse configuration of the MICON A/S Distributed Control System for project B610. The following will be verified: proper assignment and operation of all field inputs to and outputs from the MICON Termination panels; proper operation of all display data on the operator`s console; proper operation of all required alarms; and proper operation of all required interlocks. The MICON A/S control system is configured to replace all the control, indication, and alarm panels now located in the Power Control Room. Nine systems are covered by this control configuration, 2736-ZB HVAC, 234-5Z HVAC, Process Vacuum, Dry Air, 291-Z Closed Loop Cooling, Building Accelerometer, Evacuation Siren, Stack CAMs, and Fire. The 2736-ZB HVAC system consists of the ventilation controls for 2736-ZB and 2736-Z as well as alarms for the emergency generators and 232-Z. The 234-5Z HVAC system is the ventilation controls for 235-5Z and 236-Z buildings. Process Vacuum covers the controls for the 26 inch vacuum system. Dry Air covers the controls for the steam and electric air dryers. The 291-Z Closed Loop Cooling system consists of the status indications and alarms for the 291-Z compressor and vacuum pump closed loop cooling system. The rest of closed loop cooling was tested earlier. The Building Accelerometer system consists of the status indications for the two seismic system accelerometers. The Evacuation Siren system includes the controls for the evacuation and take cover sirens. Stack CAMs cover the alarms for the various building ventilation stack continuous air monitors. Finally, the Fire system covers the various fire alarms now located in Room 321-A.

  6. Richland Environmental Restoration Project management action process document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This document is the prescribed means for providing direct input to the US Department of Energy Headquarters regarding the status, accomplishments, strategy, and issues of the Richland Environmental Restoration Project. The project mission, organizational interfaces, and operational history of the Hanford Site are provided. Remediation strategies are analyzed in detail. The document includes a status of Richland Environmental Restoration project activities and accomplishments, and it presents current cost summaries, schedules, and technical baselines.

  7. Post Process Characterization of Friction Stir Welded Components Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations Incorporated proposes in this STTR Phase II project to continue development and validation of Luna's amplitude-dependent, nonlinear ultrasonic...

  8. Implications of critical chain methodology for business process flexible automation projects in economic organizations

    Directory of Open Access Journals (Sweden)

    Paul BRUDARU

    2009-12-01

    Full Text Available Business processes flexible automation projects involve the use of methods and technologies from Business Processes Management area (BPM that aim at increasing the agility of organizations in changing the business processes as response to environmental changes. BPM-type projects are a mix between process improvement projects and software development which implies a high complexity in managing them. The successful implementation of these projects involves overcoming problems inherent as delays in the activities of projects, multi-tasking, lack of focus which can not be solved by traditional project management tools. An approach which takes account of the difficulties of BPM projects is critical chain methodology. Using critical chain method provides the methodology fundament necessary for the successful completion of BPM-type projects.

  9. Carbonate Looping for De-Carbonization of Cement Plants

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Andersen, Maria Friberg; Lin, Weigang

    2011-01-01

    Cement industry is one of the largest emitter of CO2 other than power generation plants, which includes the emissions from combustion of fuel and also from calcination of limestone for clinker production. In order to reduce CO2 emissions from the cement industry an effective an economically...... feasible technology is to be developed. The carbonate looping process is a promising technology, which is particularly suitable for the cement industry as limestone could be used for capture and release of CO2. Integration of carbonate looping process into cement pyroprocess has two advantages: 1...... integrated into cement pyro-process. The energy required for regeneration in the calciner increases with increase in average conversion of calcined limestone and energy that can be extracted from carbonator decreases with increasing average conversion. Further the influence of type of limestone...

  10. Ready to Retrofit: The Process of Project Team Selection, Building Benchmarking, and Financing Commercial Building Energy Retrofit Projects

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Mark D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Parrish, Kristen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mathew, Paul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-05-01

    This guide presents a process for three key activities for the building owner in preparing to retrofit existing commercial buildings: selecting project teams, benchmarking the existing building, and financing the retrofit work. Although there are other essential steps in the retrofit process, the three activities presented in this guide are the critical elements where the building owner has the greatest influence on the outcome of the project.

  11. CO2 Capture for Cement Technology

    OpenAIRE

    2013-01-01

    Production of cement is an energy intensive process and is the source of considerable CO2emissions. Itis estimated that the cement industry contributes around 8% of total global CO2emissions. CO2is oneof the major greenhouse gases. In the atmosphere, the CO2concentration has increased from 310 ppmvin 1960 to 390 ppmv in 2012, probably due to human activity. A lot of research is being carried out forreducing CO2emissions from large stationary sources. Ofwhich, the carbonate looping process is ...

  12. Utilisation and Improvement of the Initialisation of Project Communication Processes During the Management of Projects in Industrial Enterprises in Slovakia

    Science.gov (United States)

    Samáková, Jana; Šujanová, Jana; Špirková, Marta

    2016-06-01

    Nowadays, project communication is slowed due to the need for compliance with strict rules. Therefore the aim of this paper is to analyse the use of the communication environment as a basic part of the initialisation of project communication in industrial enterprises in Slovakia, and to propose measures to improve the process of initialisation of project communication in these enterprises. In this paper, theoretical and empirical research (quantitative and qualitative) approaches were chosen. On the basis of the research we can conclude, that communication as a basic part of the "Initialisation of project communication" is not adequately elaborated in international methodologies and standards of project management and in industrial enterprises. Industrial enterprises do not deal with processes of the communication environment and this results in negative consequences.

  13. A new approach to quantify trabecular resorption adjacent to cemented knee arthroplasty.

    NARCIS (Netherlands)

    Mann, K.A.; Miller, M.A.; Pray, C.L.; Verdonschot, N.J.J.; Janssen, D.

    2012-01-01

    A new micro-computed tomography (muCT) image processing approach to estimate the loss of cement-bone interlock was developed using the concept that PMMA cement flows and cures around trabeculae during the total knee arthroplasty procedure. The initial mold shape of PMMA cement was used to estimate t

  14. Using bio-based polymers for curing cement-based materials

    NARCIS (Netherlands)

    Zlopasa, J.; Koenders, E.A.B.; Picken, S.J.

    2014-01-01

    Curing is the process of controlling the rate and extent of moisture loss from the surface of cement based materials. It is the final stage in the production of cement-based materials and it is the essential part for achieving continuous hydration of cement, while avoiding cracking due to drying shr

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

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module deals with the materials used in making concrete hollow blocks. Topics discussed include: (1) igneous, metamorphic, and sedimentary rocks; (2) weathering (the process of breaking down rocks) and its effects on rocks; (3) cement; (4) stages in the manufacturing of Portland cement; and (5) the transformation of cement into concrete…

  16. Pack cementation coatings for alloys

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Rong; Zheng, Minhui; Rapp, R.A. [Ohio State Univ., Columbus, OH (United States)

    1996-08-01

    The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on a Cr-Cr{sub 2}Nb alloy in a single processing step. The morphology and composition of the coating depended both on the composition of the pack and on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi{sub 2} and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. In cyclic and isothermal oxidation in air at 700 and 1050{degrees}C, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation by the formation of a Ge-doped silica film. The codeposition and diffusion of aluminum and chromium into low alloy steel have been achieved using elemental Al and Cr powders and a two-step pack cementation process. Sequential process treatments at 925{degrees}C and 1150{degrees}C yield dense and uniform ferrite coatings, whose compositions are close to either Fe{sub 3}Al or else FeAl plus a lower Cr content, when processed under different conditions. The higher content of Al in the coatings was predicted by thermodynamic calculations of equilibrium in the gas phase. The effect of the particle size of the metal powders on the surface composition of the coating has been studied for various combinations of Al and Cr powders.

  17. Acoustic response of cemented granular sedimentary rocks: molecular dynamics modeling.

    Science.gov (United States)

    García, Xavier; Medina, Ernesto

    2007-06-01

    The effect of cementation processes on the acoustical properties of sands is studied via molecular dynamics simulation methods. We propose numerical methods where the initial uncemented sand is built by simulating the settling process of sediments. Uncemented samples of different porosity are considered by emulating natural mechanical compaction of sediments due to overburden. Cementation is considered through a particle-based model that captures the underlying physics behind the process. In our simulations, we consider samples with different degrees of compaction and cementing materials with distinct elastic properties. The microstructure of cemented sands is taken into account while adding cement at specific locations within the pores, such as grain-to-grain contacts. Results show that the acoustical properties of cemented sands are strongly dependent on the amount of cement, its stiffness relative to the hosting medium, and its location within the pores. Simulation results are in good correspondence with available experimental data and compare favorably with some theoretical predictions for the sound velocity within a range of cement saturation, porosity, and confining pressure.

  18. A Process Towards Societal Value within a Community-Based Regional Development Project

    Directory of Open Access Journals (Sweden)

    Anna Åslund

    2012-12-01

    Full Text Available Processes, activities and tasks of a community-based area development project are described. The main process has been used three times and a model is presented. An earlier developed process map has been verified. The description of the project can help other communities to plan development projects. The illustration can be valuable for entrepreneurs who are planning a societal value initiative and for decision-makers and stakeholders who can contribute to, are concerned with, or may be affected by societal entrepreneurship. Observation, participating studies, dokumentations and an interview with the project leader has been carried out. Data have been analyzed and compared with the previously developed process map to achieve a deeper understanding of the processes within societal entrepreneurship. The purpose was to study and describe the processes of a community-based area development project and to compare it with a previously developed process map and to verify the process map.

  19. Quality control of cemented waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Slate, L.J.

    1994-12-31

    To insure that cemented radwaste remains immobilized after disposal, certain standards have been set in Europe by the Commission of the European Communities. One such standard is compressive strength. If the compressive strength can be predicted during the early curing stages, time and money can be saved and the quality of the final waste form guaranteed. It was determined that the 7- and 28-day compressive strength from radwaste cementation can be predicted during the mixing and early curing stages by at least three methods. The three that were studied were maturity, rheology, and impedance. Maturity is a temperature-to-time measurement, rheology is a shear stress-to-shear rate measurement, and impedance is the opposition offered to the flow of alternating current. These three methods were employed on five different cemented radwaste concentrations with three different water-to-cement ratios; thus, a total of 15 different mix designs were considered. The results showed that the impedance was the easiest to employ for an on-line process. The results of the impedance method showed a very good relationship between impedance and water-to-cement ratio; therefore, an accurate prediction of compressive strength of cemented radwaste can be drawn from this method. The results of the theology method were very good. The method showed that concrete conforms to the Bingham plastic rheologic model, and the theology method can be used to predict the compressive strength of cemented radwaste, but may be too cumbersome. The results of the maturity method were shown to be limited in accuracy for determining compressive strength.

  20. Process-oriented knowledge-sharing platform for chemical engineering design projects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A process-oriented knowledge-sharing platform is studied to improve knowledge sharing and project management of chemical engineering design enterprises. First, problems and characteristics of knowledge sharing in multi-projects of chemical engineering design are analyzed. Then based on theories of project management, process management, and knowledge management, a process-oriented knowledge-sharing platform is proposed. The platform has three characteristics: knowledge is divided into professional knowledge...

  1. An application of stochastic processes for analyzing risks in highway projects

    Directory of Open Access Journals (Sweden)

    S. Meysam Mousavi

    2015-01-01

    Full Text Available The successes on highway projects are uncertain because of organizational features, improper scope definitions and long lasting complicated processes. Highway projects under uncertain environment can effectively be managed with the application of risk management throughout their life cycles. Risk management within highway projects, therefore, has been recognized vital to improve their performances and increase the success of these projects. Processes of the projects are dynamic by nature. Therefore, commonly used static techniques do not analyze the potential risks properly. The stochastic process is a highly effective tool to quantitatively deal with the risk analysis. In this paper, a new approach based on Markov chain is proposed to assess the potential risks of highway projects in a dynamic framework. The approach takes advantage of the capability of probabilistic tools. Furthermore, using an application example in highway projects, the proposed approach is demonstrated in detail. Finally, the risk management effectiveness of using the stochastic processes is illustrated.

  2. Influence of the joint incorporation of CaF2 and CaSO4 in the clinkerization process. Obtainment of new cements

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    1995-09-01

    Full Text Available This article review the state of the art on the effect of the joint incorporation of fluorides and sulfates to the cement crudes. This incorporation may be carried out partially replacing the traditional crudes, thus obtaining a new cement produced with a considerable energy saving and with advantageous characteristics with regard to the traditional cement. The work presents a study of equilibrium diagrams of interest and mentions some industrial experiences developed by the researchers, authors of this article.En el presente artículo se revisa el estado del conocimiento sobre el efecto que ejerce la incorporación conjunta de fluoruros y sulfatos a crudos de cemento. Esta incorporación puede realizarse sustituyendo parcialmente los crudos tradicionales, obteniéndose así un nuevo cemento que se produce con un considerable ahorro energético y con prestaciones ventajosas respecto al tradicional. Se hace un estudio de los diagramas de equilibrio de interés y se citan algunas experiencias industriales desarrolladas por los investigadores autores del artículo.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. ACACIA Project – Development of a Post-Combustion CO2 Capture Process. Case of the DMXTM Process

    Directory of Open Access Journals (Sweden)

    Gomez A.

    2014-11-01

    Full Text Available The objective of the ACACIA project was to develop processes for post-combustion CO2 capture at a lower cost and with a higher energetic efficiency than first generation processes using amines such as MonoEthanolAmine (MEA which are now considered for the first Carbon Capture and Storage (CCS demonstrators. The partners involved in this project were: Rhodia (Solvay since then, Arkema, Lafarge, GDF SUEZ, Veolia Environnement, IFP Energies nouvelles, IRCE Lyon, LMOPS, LTIM, LSA Armines. To validate the relevance of the breakthrough processes studied in this project, techno-economic evaluations were carried out with comparison to the reference process using a 30 wt% MEA solvent. These evaluation studies involved all the industrial partners of the project, each partner bringing specific cases of CO2 capture on their industrial facilities. From these studies, only the process using demixing solvent, DMXTM, developed by IFPEN appears as an alternative solution to the MEA process.

  5. Jinchuan Group Breaks Ground for a 300,000-ton Copper Deep Processing Project

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>According to Jinchang Municipal Government of Gansu,on August 21,Jinchuan Group broke ground for its 400,000-ton ionic membrane caustic soda project,300,000-ton PVC project,300,000-ton copper deep processing project,

  6. The fluid-compensated cement bond log

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, T.H.; Leslie, H.D.; Wheelis, W.B.

    1984-09-01

    An experimental and numerical wave mechanics study of cement bond logs demonstrated that wellsite computer processing can now segregate wellbore fluid effects from the sonic signal response to changing cement strength. Traditionally, cement logs have been interpreted as if water were in the wellbore, without consideration of wellbore fluid effects. These effects were assumed to be negligible. However, with the increasing number of logs being run in completion fluids such as CaCl/sub 2/, ZnBr/sub 2/, and CaBr/sub 2/, large variations in cement bond logs became apparent. A Schlumberger internal paper showing that bond log amplitude is related to the acoustic impedance of the fluid in which the tool is run led to a comprehensive study of wellbore fluid effects. Numerical and experimental models were developed simulating wellbore geometry. Measurements were conducted in 5-, 7-, and 95/8-in. casings by varying the wellbore fluid densities, viscosities, and fluid types (acoustic impedance). Parallel numerical modeling was undertaken using similar parameters. The results showed that the bond log amplitude varied dramatically with the wellbore fluid's acoustic impedance; for example, there was a 70 percent increase in the signal amplitude for 11.5-lb/ gal CaCl/sub 2/ over the signal amplitude in water. This led to the development of a Fluid-Compensated Bond log that corrects the amplitude for acoustic impedance of varying wellbore fluids, thereby making the measurements more directly related to the cement quality.

  7. A Novel Method for Assessing and Optimizing Software Project Process Based Risk Control

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new approach for assessing and optimizing software project process based on software risk control pre-sented, which evaluates and optimizes software project process from the view of controlling the software project risks. A model for optimizing software risk control is given, a discrete optimization algorithm based on dynamic programming is proposed and an example of using above method to solve a problem is also included in this paper. By improving the old passive post-project control into an active effective pre-action, this new method can greatly promote the possibility of success of software projects.

  8. Numerical Simulation of Projection Welding Processes for Door Hinge of Automobile Based on Coupled Fields Analysis

    Institute of Scientific and Technical Information of China (English)

    QIAN Chang-ming; LUO Ai-hui; CHEN Guan-long

    2007-01-01

    Projection welding is a variation of electric resistance welding with the dynamic changes of the flow paths for heat and electrical properties with changing temperature caused by the large plastic deformation collapse of projection. As the joint type between the auto door hinge and the inner plate, projection welding may bring welding distortions and would affect the assembly quality of auto body. A comprehensive electric-thermal-mechanical numerical simulation was performed to quantitatively simulate the processes of projection welding by using a coupled finite element method. The mechanism of projection collapse and the formation process of nugget were discussed and good conclusions have been achieved comparing with the test results.

  9. 硬化砂浆中水泥含量试验制样方法探讨%Discussion about sample processing methods of cement content in hardened mortars

    Institute of Scientific and Technical Information of China (English)

    张亚涛; 刘磊; 张成银; 秦岭; 姬钰

    2016-01-01

    In order to get the result that is close to the real value of cement content in hardened mortars , different samples with varied content of fly ash were prepared .After the mortar samples were cured for a certain age in a standard environment , based on the loss of bound water in hardened cementitious materials,the effect of different sample processing methods on cement content in hardened mortars was investigated via CaO measurements .The authors found an ideal processing method , that is after stopping hydration by anhydrous ethanol , sample was blast dried at 60 ℃, then temperature was increased from room temperature to (520 ±10) ℃ in the rate of 10 ℃/min,and then maintaining for 1h.The bound water content is one of the key factors to the measurement results of cement content in hardened mortars . By using this processing method , the relative deviation of cement content of hardened mortars with different ages and fly ash content is set within ±5%.%为探索处理硬化砂浆试样的方法,使水泥含量测定结果更接近真实值,首先成型不同粉煤灰掺量的砂浆试样,在砂浆试样标准养护到一定龄期后,基于硬化胶凝材料中结合水的损失过程,利用CaO测定法研究不同的试样处理方法对硬化砂浆中水泥含量测定结果的影响,得到处理硬化砂浆试样的方法:即无水乙醇终止水化后,60℃鼓风烘干,然后以10℃/min的速度由室温升到(520±10)℃,保持1 h,并且通过实验证明结合水含量是影响硬化砂浆中水泥含量测定结果的关键因素之一。采用该方法处理后,不同龄期相同胶凝材料含量和同一龄期不同粉煤灰掺量硬化砂浆中水泥含量测定结果的相对误差都在±5%以内。

  10. Cementing Properties of Oil Shale Ash

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The oil crisis has prompted renewed interest in direct burning of oil shale as an alternative energy source.A major problem in this process is the large portion of ash produced.The cementing properties of this ash were investigated to determine its applicability as a building material.By means of XRD, IR, NMR and ICP, we have studied the effects of burning temperature on the reactivity of ash.Maximum reactivity was obtained with ash samples produced at 700 °C to 900 °C.In this range, the strength of oil-shale-based material, with properties similar to cement, which is composed of oil shale and several other kinds of solid wastes, can achieve the standard of 42.5# cement.Our study has provided an experimental foundation and theoretical base for a massive utilization of oil shale.

  11. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    LENUS (Irish Health Repository)

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  12. Cement Mason's Curriculum. Instructional Units.

    Science.gov (United States)

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  13. Cementing a wellbore using cementing material encapsulated in a shell

    Energy Technology Data Exchange (ETDEWEB)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  14. Cementing a wellbore using cementing material encapsulated in a shell

    Science.gov (United States)

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  15. Technology Roadmaps: Cement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  16. Cement og politik

    DEFF Research Database (Denmark)

    Lund, Joachim

    2012-01-01

    as well as in the public sphere. Most of the extensive job creating measures he carried out as a minister for public works necessarily involved the use of great amounts of cement – the primary produce of F.L. Smidth & Co. Gunnar Larsen thus became an easy target for Communist propaganda, picturing him...... of the Soviet Union (including an F.L. Smidth & Co. cement plant in former Estonia). He spent the last 15 months of the occupation in Sweden and was arrested after having returned to Copenhagen in May, 1945. Although a Copenhagen city court prison sentence for economic collaboration was reversed, he had...

  17. Development of a Multipurpose Extruder/Press Food Processing System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is to develop versatile, low mass, energy efficient, and easily maintained multipurpose seed processing (MSP) equipment for food processing in space...

  18. SpiderFab: Process for On-Orbit Construction of Kilometer-Scale Apertures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project develops a process for automated on-orbit construction of very large structures and multifunctional components. The foundation of this process is a...

  19. Process performance indicators in project pre-design stage

    NARCIS (Netherlands)

    Haponava, T.; Al-Jibouri, S.; Reymen, I.

    2006-01-01

    Traditionally performance in construction is measured based on the "iron-triangle”- time, cost and quality. In recent years indicators have been developed to include the measurements of other aspects of project performance. The main shortcoming of these however is that most of them are lagging indic

  20. A functional-dynamic reflection on participatory processes in modeling projects.

    Science.gov (United States)

    Seidl, Roman

    2015-12-01

    The participation of nonscientists in modeling projects/studies is increasingly employed to fulfill different functions. However, it is not well investigated if and how explicitly these functions and the dynamics of a participatory process are reflected by modeling projects in particular. In this review study, I explore participatory modeling projects from a functional-dynamic process perspective. The main differences among projects relate to the functions of participation-most often, more than one per project can be identified, along with the degree of explicit reflection (i.e., awareness and anticipation) on the dynamic process perspective. Moreover, two main approaches are revealed: participatory modeling covering diverse approaches and companion modeling. It becomes apparent that the degree of reflection on the participatory process itself is not always explicit and perfectly visible in the descriptions of the modeling projects. Thus, the use of common protocols or templates is discussed to facilitate project planning, as well as the publication of project results. A generic template may help, not in providing details of a project or model development, but in explicitly reflecting on the participatory process. It can serve to systematize the particular project's approach to stakeholder collaboration, and thus quality management.

  1. Macrodefect-free cements: chemistry and impact of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Drabik, M.; Galikova, L.; Mojumdar, S.C. [Slovak Academy of Sciences, Bratislava (Slovakia). Inst. of Inorganic Chemistry

    2002-07-01

    To control and improve the moisture resistance is a long felt necessity of the MDF cements, chemical approaches together with material science contribute to the progress. Present results support our previous hypothesis about the impregnation or barier effect of poly-P on the MDF cements and enlarge the validity of this hypothesis to the blends of SAFB clinker, Portland cement and HPMC or poly-P. Compactness of Al(Fe)-O-P cross-links increases the intrinsic density and, consequently, impregnates the system against the uptake of moisture. In a sense of the theory of functional polymers, the intensity of grafting of polymer chains to the surface of grains increases if poly-P is used and with the prolonged processing. The scope of moisture attack on MDF cements synthesized from the blends of SAFB clinker, Portland cement and HPMC or poly-P, as quantified using mass changes as measure of moisture resistance, is strongly affected by the nature of polymer. The addition of Portland cement in the raw mix improves the moisture resistance of MDF cements. Thermal analysis shows: (i) the irreversible mass gain of 3 - 10% is arisen from carbonation and secondary hydration of cement grains and (ii) the Al(Fe)-O-C(P) cross-links remain intact in the moist environment at either ambient or extreme levels of humidity. (orig.)

  2. Biocompatibility of alendronate-loaded acrylic cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    T Calvo-Fernández

    2010-10-01

    Full Text Available This paper reports a biological evaluation of a non-resorbable acrylic cement loaded with alendronate for the treatment of osteoporotic vertebral compression fractures. The cement formulation was based on polymethyl methacrylate and acrylic monomers; one of these had covalently linked vitamin E residues. The same cement in the absence of alendronate was used as a control. The setting of the charged cement presented a maximum polymerization temperature of 44ºC, a setting time of 24 min, a residual monomer content lower than 3 wt.%, a compressive strength of 99±10 MPa and an elastic modulus of 1.2±0.2 GPa. Cytotoxicity studies using human osteoblast cultures revealed that the leachable substances of the alendronate loaded cement collected between 1 and 7 days decreased cell viability to values lower than 80%. However, morphological changes and cellular damage in cells produced by the extracts decreased with the leak time. Cell adhesion and growth on charged cement was significantly lower than on the control. Implantation of the cement paste in the intra-femoral cavity of rabbits showed that initially the osteogenic activity was evident for the cement charged with alendronate, and the osteosynthesis process took place mainly in the trabeculae and was manifested by the presence of a non-mineralised osseous spicule. The interface between material and adjacent bone tissue was initially characterized by a variable fibrous response that in many cases it appeared reduced to thin connective tissue after a 24-week-period.

  3. Ageing of Dry Cement Mixes for Finishing Purposes

    Directory of Open Access Journals (Sweden)

    Bronius VEKTARIS

    2013-09-01

    Full Text Available Dry building mixes, stored in the air, absorb water vapor and CO2 gas and ageing because properties of binding materials, mostly Portland cement, deteriorate after its prehydration and carbonation. In this paper the ageing singularities of dry cement mixes for finishing purposes and additives for retarding this process has been determinated. Ordinary and quickly hardening Portland cements absorb H2O and CO2 more than white cement – about 70 % – 75 % and 30 % – 38 % per month of innitial mass, respectively. White cement is more resistant to prehydration and carbonation, because it contains less C3A, C4AF and alkali, characterized initial activity. Dry mixes with white cement, although slower, but still worse after stored. Influence of routine dry mortar mixes ingredients and additives (methyl cellulose, pigments, sand and lime on prehydration properties of the mixes for finishing purpose is not substantial. Significant positive influence comes from the addition of fatty acid salts (zinc stearate or sodium oleate. The dry cement mixes for finishing purpose has been recomended to hydrophobisate with one of these additives, adding about 1 % by weight of cement during preducing mixes. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5243

  4. Autonomous, On-board Processing for Sensor Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fuse high performance reconfigurable processors with emerging fault-tolerance & autonomous processing techniques for a 10-100x decrease in processing time. This...

  5. Assessing CO2 interaction with cement and steel over a two-year injection period: current state and future risks for the MovECBM project in Poland

    NARCIS (Netherlands)

    Loizzo, M.; Bressers, P.; Benedictus, T.; Guen, Y. le; Poupard, O.

    2009-01-01

    On the site of Kaniow (Poland) a new well was used to inject supercritical CO2 into coal seams over a two year period. The injection was part of an experiment on Enhanced Coal-Bed Methane recovery sponsored by the RECOPOL and MovECBM European project. Part of the interest in ECBM is the possibility

  6. Analysis and Development of a Project Evaluation Process.

    Energy Technology Data Exchange (ETDEWEB)

    Coutant, Charles C.; Cada Glenn F.

    1985-01-01

    The Bonneville Power Administration has responsibility, assigned by the Pacific Northwest Electric Power Planning and Conservation Act of 1980 (Public Law 96-501; 16 USC 839), for implementing the Columbia River Basin Fish and Wildlife Program of the Northwest Power Planning Council. One aspect of this responsibility is evaluation of project proposals and ongoing and completed projects. This report recommends formalized procedures for conducting this work in an accurate, professional, and widely respected manner. Recommendations and justifications are based largely on interviews with federal and state agencies and Indian tribes in the Northwest and nationally. Organizations were selected that have evaluation systems of their own, interact with the Fish and Wildlife Program, or have similar objectives or obligations. Perspective on aspects to be considered were obtained from the social science of evaluation planning. Examples of procedures and quantitative criteria are proposed. 1 figure, 2 tables.

  7. YES Africa: Geoscience Projects for Development (GPD) (Strategy and Process)

    Science.gov (United States)

    Barich, A.; Nkhonjera, E.; Venus, J.; Gonzales, L. M.

    2011-12-01

    For various reasons, Earth Science in Africa has been acareer path that has not been promoted or a preferred option. In January 2011, the YES Network in Africa launched the Network in Africa through a symposium. This took place at the University of Johannesburg, in conjunction with the Colloquium of Africa Geology in January 2011. The Symposium brought together young geoscientists from all regions of Africa to talk about their geoscience research that focused on geohazards and professional development within the African continent. The YES Africa Symposium also aimed to improve the participation of students in African geosciences issues and to also discuss how geoscience education in Africa can be promoted to attract more students to choose a career in the profession. The YES Africa Symposium resulted in ambitious short/long term projects. Symposium participants agreed unanimously that spreading awareness throughout the society about geological hazards, climate change, water management strategies and sustainable development remains a priority. As a direct result local projects are being developed by the YES Network's African National Chapters to develop a long-term geoscience taskforce within the continent. These projects will be developed by implementing student chapters in universities and strengthening the ties with local geoscience organizations and governments. Many YES Network African National Chapters have already taken the lead in developing their local projects, and some have been very successful in their efforts. Collaboration with the various YES Network National Chapters will be critical in developing a geo-hazard portal which links regional organizations and institutions together. This will help to disseminate geo-information more efficiently, and also to develop the next generation of young African geoscience students and early-career professionals. This presentation will detail a variety of innovative outreach methods used to connect with the public

  8. Quality tools in a process of technical project management

    OpenAIRE

    Gwiazda, A.

    2006-01-01

    Purpose: The aim of this paper is to show how it could utilize the tools of quality management for the processof project management. Also it could be presented a modification of the Ishikawa diagram.Design/methodology/approach: In presented work has been applied the research methodology that bases onthe theoretical analysis and on the empirical researches. It is also presented a practical solution that proved thevalidity of proposed method.Findings: The base finding of the presented work is t...

  9. Process for planning and control of software projects using XedroGESPRO

    Directory of Open Access Journals (Sweden)

    Jacqueline Marín-Sánchez

    2014-04-01

    Full Text Available The software project management in Cuba has become a key area for improving production processes and decisionmaking in organizations. Several models and standards for process improvement, related with project management, proposed best practices on issues of planning and control of projects. However, they are generic guidelines that describe only those activities to execute, leaving the responsibility for implementing to organizations, using sometimes , expensive proprietary informatics tools to achieve these goals. This research proposes a process for planning and control of software projects using Xedro-GESPRO: an open-source software tool for project management domestically implemented. The proposal is successfully being applied by the network of production centers of the Informatic Sciences University of Cuba, observing greater efficiency and effectiveness in the planning and control of their projects.

  10. Osteotransductive bone cements.

    Science.gov (United States)

    Driessens, F C; Planell, J A; Boltong, M G; Khairoun, I; Ginebra, M P

    1998-01-01

    Calcium phosphate bone cements (CPBCs) are osteotransductive, i.e. after implantation in bone they are transformed into new bone tissue. Furthermore, due to the fact that they are mouldable, their osteointegration is immediate. Their chemistry has been established previously. Some CPBCs contain amorphous calcium phosphate (ACP) and set by a sol-gel transition. The others are crystalline and can give as the reaction product dicalcium phosphate dihydrate (DCPD), calcium-deficient hydroxyapatite (CDHA), carbonated apatite (CA) or hydroxyapatite (HA). Mixed-type gypsum-DCPD cements are also described. In vivo rates of osteotransduction vary as follows: gypsum-DCPD > DCPD > CDHA approximately CA > HA. The osteotransduction of CDHA-type cements may be increased by adding dicalcium phosphate anhydrous (DCP) and/or CaCO3 to the cement powder. CPBCs can be used for healing of bone defects, bone augmentation and bone reconstruction. Incorporation of drugs like antibiotics and bone morphogenetic protein is envisaged. Load-bearing applications are allowed for CHDA-type, CA-type and HA-type CPBCs as they have a higher compressive strength than human trabecular bone (10 MPa).

  11. Destruction of meat and bone meals in cement plants; Destruction des farines animales dans les cimenteries

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-10-01

    Following the crisis of the bovine spongiform encephalopathy disease ('mad cow' disease), the French cement industrialists have been requested by the government since 1996 to eliminate the forbidden meat and bone meals in cement kilns where they are used as fuel substitutes. This article presents the advantages of the cement industry file in the destruction of such wastes, the validation and the safety aspects of this process. Meat and bone meal represents a high-grade fuel that lowers the environmental impact of cement production and does not affect the quality of cement. (J.S.)

  12. PURIFIED WASTE FCC CATALYST AS A CEMENT REPLACEMENT MATERIAL

    Directory of Open Access Journals (Sweden)

    Danute Vaiciukyniene

    2015-06-01

    Full Text Available Zeolites are commonly used in the fluid catalytic cracking process. Zeolite polluted with oil products and became waste after some time used. The quantity of this waste inevitably rises by expanding rapidly oil industry. The composition of these catalysts depends on the manufacturer and on the process that is going to be used. The main factors retarding hydration process of cement systems and modifying them strength are organic compounds impurities in the waste FCC catalyst. The present paper shows the results of using purified waste FCC catalyst (pFCC from Lithuania oil refinery, as Portland cement replacement material. For this purpose, the purification of waste FCC catalyst (FCC samples was treated with hydrogen peroxide. Hydrogen peroxide (H2O2 is one of the most powerful oxidizers known. By acting of waste with H2O2 it can eliminate the aforementioned waste deficiency, and the obtained product becomes one of the most promising ingredients, in new advanced building materials. Hardened cement paste samples with FCC or pFCC were formed. It was observed that the pFCC blended cements developed higher strength, after 28 days, compared to the samples with FCC or reference samples. Typical content of Portland cement substituting does not exceed 30 % of mass of Portland cement in samples. Reducing the consumption of Portland cement with utilizing waste materials is preferred for reasons of environmental protection.

  13. Project and Innovation Management in New Product Development Processes

    DEFF Research Database (Denmark)

    Henriksen, Leif; Gayretli, Ahmet

    2010-01-01

    Although the process of innovation is one of the most important drivers behind the growth and prosperity of today’s global economy, it is one of the least understood. This paper aims to address specific problems in carrying out new product development processes. There are crucial issues related......, a process platform, and a technology platform. Even if there is no single solution to these complex problems the proposed method can offer a more structured way of attacking the issues....

  14. Accelerated Numerical Processing API Based on GPU Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The recent performance increases in graphics processing units (GPUs) have made graphics cards an attractive platform for implementing computationally intense...

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

    Science.gov (United States)

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

    2006-10-01

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

  16. WC基钢结硬质合金磨损机理研究%STUDY OF WEAR MECHANISM OF THE WC STEEL-BONDED CEMENTED CARBIDE MANUFACTURED BY A NEW PROCESS

    Institute of Scientific and Technical Information of China (English)

    杜晓东; 尤显卿; 郑玉春

    2001-01-01

    The WC steel-bonded cemented carbide manufactured by a new process w as oil-quenched at 1150℃ and tempered at the low temperature 150℃ after anneal ing, and its wearability and wear mechanism were analyzed. The results show that the wear of the tested cemented carbide is caused by flaking of the hard phase, and that the development and propagation of cracks along the phase boundary between the hard phase and the substrate or the other hard phase is the reason why the h ard phase flakes.%将新工艺制造的WC钢结硬质合金退火后经1150℃油淬,150℃低温回火,分析其磨损特性和磨损机理,结果表明实验合金的磨损是由硬质相剥落造成的,裂纹沿硬质相与基体或硬质相之间的相界面萌生和扩展是硬质相剥落的原因。

  17. Project B610 process control configuration acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, G.R.

    1995-06-27

    The purpose of this test is to verify the Westinghouse configuration of the MICON A/S Distributed Control System for project B610. The following will be verified: (1) proper assignment and operation of all field inputs to and outputs from the MICON Termination panels; (2) proper operation of all display data on the operators` console; (3) proper operation of all required alarms; and (4) proper operation of all required interlocks. This test only verifies the proper operation of the Westinghouse control configuration (or program). It will not be responsible for verifying proper operation of the MICON hardware or operating software. Neither does it test any of the B610 instrument. The MICON hardware and software has been tested as part of the equipment procurement. Instrumentation and wiring installed under project B620 will be tested under a separate functional test. In some cases, precise transmitter ranges, alarm setpoints, and controller tuning parameters are not available at this time. Therefore, approximate values are used during the test. This should not affect the proper operation of the configuration or the validity of this test. Final values will be assigned during operability testing.

  18. Energy conservation in citrus processing. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Leo, M.A.; Lari, R.I.; Moore, N.R.; Broussard, M.R.; Gyamfi, M.

    1981-11-01

    Alternative energy conserving systems for use in citrus processing plants were synthesized and evaluated in terms of energy savings and economic return. The energy intensive operations that are carried out in citrus processing plants include conveying and extraction, concentration, peel drying, refrigeration, and pasteurization. The alternative energy conserving systems are synthesized from components and subsystems that are arranged to make use of energy cascading and thermodynamic regeneration to reduce the overall energy usage. System requirements such as air pollution rules and plant processing load cycles, a characterization of major operations, description of alternative system concepts, and the evaluation of alternative systems in terms of economic parameters and energy usage are identified.

  19. Durability of pulp fiber-cement composites

    Science.gov (United States)

    Mohr, Benjamin J.

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

  20. Reactive Atom Plasma Processing of Slumped Glass Wedges Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Reactive Atom Plasma (RAPTM) process will be evaluated as a rapid and practical method for fabricating precision wedges in glass sheets. The glass sheets are to...

  1. Reactive-Separator Process Unit for Lunar Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's plans for a lunar habitation outpost call out for process technologies to separate hydrogen sulfide and sulfur dioxide gases from regolith product gas...

  2. Nanorack Compatible Standardized Data Processing, Communication, and Control Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I study will design and develop a NanoRacks Control Module (NCM) that provides communications, control functions and data processing in a NanoRacks...

  3. Enhancing the Processing Characteristics of Edible Beans Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced life-support systems, which use chemical, physical, and biological processes, are being developed to support future long-term human planetary exploration....

  4. Onboard Optical Navigation Measurement Processing in GEONS Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this IRAD is to establish in-house onboard OpNav measurement data processing capabilities through software development and testing.  Software...

  5. Real-Time Smart Tools for Processing Spectroscopy Data Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose novel and real-time smart software tools to process spectroscopy data. Material abundance or compositional maps will be generated for rover guidance,...

  6. Integrating chemical engineering fundamentals in the capstone process design project

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Woodley, John; Johnsson, Jan Erik

    2010-01-01

    to each other. Similarly, in process design, steady state is always assumed for processes (i.e. production of a given chemical occurs at a constant rate, temperature, pressure and composition; feeds enter the plant at constant rates, etc.). However, in practice, chemical plants need to be carefully......, Process Design provides an opportunity for a comprehensive implementation of CDIO principles in a single course. Already the traditional chemical engineering “capstone” design course has for decades embodied many of the essential features of CDIO (for example the focus on group work, development......All B.Eng. courses offered at the Technical University of Denmark (DTU) must now follow CDIO standards. The final “capstone” course in the B.Eng. education is Process Design, which for many years has been typical of chemical engineering curricula worldwide. The course at DTU typically has about 30...

  7. Crack Closure Based Self Healing Process for Metallic Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Analytical Services and Materials, Inc. (AS&M) is proposing to develop and validate a process that can extend the fatigue life of and potentially self-heal...

  8. Fault Management: Degradation Signature Detection, Modeling, and Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fault to Failure Progression (FFP) signature modeling and processing is a new method for applying condition-based signal data to detect degradation, to identify...

  9. Broadband Reflective Coating Process for Large FUVOIR Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ZeCoat Corporation will develop and demonstrate a set of revolutionary coating processes for making broadband reflective coatings suitable for very large mirrors (4+...

  10. In vitro ageing of brushite calcium phosphate cement.

    Science.gov (United States)

    Grover, L M; Knowles, J C; Fleming, G J P; Barralet, J E

    2003-10-01

    In vivo studies investigating the use of brushite cements have demonstrated mixed results with one or more of dissolution, hydrolysis, fragmentation and long term stability being demonstrated. It has been suggested that sample volume, implant location, and species can affect in vivo behaviour. As few in vitro studies on this cement system have been performed, this study aimed to compare the effects of static and dynamic in vitro ageing protocols on the phase composition, weight loss and mechanical properties of brushite cement. The effects of immersion liquid to cement volume ratio (LCVR) and sample volume on phase composition were investigated and comparative in vitro experiments were also performed in foetal bovine serum. It was determined that the weight loss after 28 days was up to seven times higher in serum than in phosphate buffered saline (PBS) and that fragmentation accounted for most of the weight loss observed. Hydroxyapatite was formed in PBS but not in serum when aged in refreshed media at all LCVRs investigated. This study has highlighted that LCVR, media refresh rate and media composition are critical to brushite cement performance. It appears that brushite cement removal from an implant site may be complex and dependent on physiological processes other than simple dissolution. A better understanding of these processes could provide the means to engineer more precise calcium phosphate cement degradation profiles.

  11. Mineral resource of the month: hydraulic cement

    Science.gov (United States)

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  12. Earth Observation data processing in the BEinGRID project

    Energy Technology Data Exchange (ETDEWEB)

    Portela, O.; Tabasco, A.; Perez, O.

    2007-07-01

    Since its emergence as a field of research in the late nineties, grid computing has evolved to become a promising technology for the embalmment of new possibilities in the realms of research and science. However, with regard to the business arena, there is still a lack of acceptance and few companies have embraced its use. Despite this situation, by providing a set of successful examples on different business areas, others will follow and grid technology will gain support as a tool for making profit along with other already established information technologies. Such is the objective of the BEinGRID project, which aims to show how a number of different fields could benefit from the usage of grid technology, among other purposes. The particular case of the Earth Observation niche is here presented in the context of this experiment, with the intention of rendering an overall picture of the real application selected and the expected advantages that the resulting system will pose. (Author)

  13. Image processing methods to obtain symmetrical distribution from projection image.

    Science.gov (United States)

    Asano, H; Takenaka, N; Fujii, T; Nakamatsu, E; Tagami, Y; Takeshima, K

    2004-10-01

    Flow visualization and measurement of cross-sectional liquid distribution is very effective to clarify the effects of obstacles in a conduit on heat transfer and flow characteristics of gas-liquid two-phase flow. In this study, two methods to obtain cross-sectional distribution of void fraction are applied to vertical upward air-water two-phase flow. These methods need projection image only from one direction. Radial distributions of void fraction in a circular tube and a circular-tube annuli with a spacer were calculated by Abel transform based on the assumption of axial symmetry. On the other hand, cross-sectional distributions of void fraction in a circular tube with a wire coil whose conduit configuration rotates about the tube central axis periodically were measured by CT method based on the assumption that the relative distributions of liquid phase against the wire were kept along the flow direction.

  14. Cement from magnesium substituted hydroxyapatite.

    Science.gov (United States)

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

    2005-05-01

    Brushite cement may be used as a bone graft material and is more soluble than apatite in physiological conditions. Consequently it is considerably more resorbable in vivo than apatite forming cements. Brushite cement formation has previously been reported by our group following the mixture of nanocrystalline hydroxyapatite and phosphoric acid. In this study, brushite cement was formed from the reaction of nanocrystalline magnesium-substituted hydroxyapatite with phosphoric acid in an attempt to produce a magnesium substituted brushite cement. The presence of magnesium was shown to have a strong effect on cement composition and strength. Additionally the presence of magnesium in brushite cement was found to reduce the extent of brushite hydrolysis resulting in the formation of HA. By incorporating magnesium ions in the apatite reactant structure the concentration of magnesium ions in the liquid phase of the cement was controlled by the dissolution rate of the apatite. This approach may be used to supply other ions to cement systems during setting as a means to manipulate the clinical performance and characteristics of brushite cements.

  15. POZZOLAN AND CEMENTS WITH POZZOLAN

    Directory of Open Access Journals (Sweden)

    Hasan KAPLAN

    1995-02-01

    Full Text Available Cement, one of the basic material of construction engineering, has an important place in view of strength and cost of structures. Cement consumption is increasing parallel to development of building construction sector. For cement producers, minimal cost is desired by using new and economical material sources. On the other hand, the controllers and contractors need cheaper, safer and higher strength materials. From this respect cement industry tends to use cement with pozzolan. In Türkiye, cement with pozzolan is produced by adding the pozzolan, which has a large reservoir in the country, in cement in sertain amount. However this type of cement is consumed in the construction sector, sortage of scientific investigation and speculative news on the subject.are worried the users and producers. In this paper, prior to an experimental study on the cements having pozzolan additive, historical development of pozzolan, reservoir of Turkiye, and comparison with portland cement is carried out. Advantages and disadvantages of pozzolan are also discussed in some points.

  16. Glass powder blended cement hydration modelling

    Science.gov (United States)

    Saeed, Huda

    .17, H/S ratio of 2.5 and N/S ratio of 0.18. In the second phase of this research, theoretical models are built using a modified version of an existing cement hydration modelling code, "CEMHYD3D", to simulate the chemical reaction of the activated glass powder hydration and glass powder in cement. The modified model, which is referred to as the "MOD-model" is further used to predict the types, compositions and quantities of reaction products. Furthermore, the glass powder hydration data, which is obtained experimentally, is incorporated into the MOD-model to determine the effect of adding glass powder to the paste on the process of cement hydration and resulting paste properties. Comparisons between theoretical and experimental results are made to evaluate the developed models. The MOD-model predictions have been validated using the experimental results, and were further used to investigate various properties of the hydrated glass powder cement paste. These properties include, for example, CH content of the paste, porosity, hydration degree of the glass powder and conventional C-S-H and GP CS-H contents. The results show that the MOD-model is capable of accurately simulating the hydration process of glass powder-blended cement paste and can be used to predict various properties of the hydrating paste.

  17. The crucial effect of early-stage gelation on the mechanical properties of cement hydrates

    Science.gov (United States)

    Ioannidou, Katerina; Kanduč, Matej; Li, Lunna; Frenkel, Daan; Dobnikar, Jure; Del Gado, Emanuela

    2016-07-01

    Gelation and densification of calcium-silicate-hydrate take place during cement hydration. Both processes are crucial for the development of cement strength, and for the long-term evolution of concrete structures. However, the physicochemical environment evolves during cement formation, making it difficult to disentangle what factors are crucial for the mechanical properties. Here we use Monte Carlo and Molecular Dynamics simulations to study a coarse-grained model of cement formation, and investigate the equilibrium and arrested states. We can correlate the various structures with the time evolution of the interactions between the nano-hydrates during the preparation of cement. The novel emerging picture is that the changes of the physicochemical environment, which dictate the evolution of the effective interactions, specifically favour the early gel formation and its continuous densification. Our observations help us understand how cement attains its unique strength and may help in the rational design of the properties of cement and related materials.

  18. The development of stochastic process modeling through risk analysis derived from scheduling of NPP project

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Ho; Roh, Myung Sub [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    There are so many different factors to consider when constructing a nuclear power plant successfully from planning to decommissioning. According to PMBOK, all projects have nine domains from a holistic project management perspective. They are equally important to all projects, however, this study focuses mostly on the processes required to manage timely completion of the project and conduct risk management. The overall objective of this study is to let you know what the risk analysis derived from scheduling of NPP project is, and understand how to implement the stochastic process modeling through risk management. Building the Nuclear Power Plant is required a great deal of time and fundamental knowledge related to all engineering. That means that integrated project scheduling management with so many activities is necessary and very important. Simulation techniques for scheduling of NPP project using Open Plan program, Crystal Ball program, and Minitab program can be useful tools for designing optimal schedule planning. Thus far, Open Plan and Monte Carlo programs have been used to calculate the critical path for scheduling network analysis. And also, Minitab program has been applied to monitor the scheduling risk. This approach to stochastic modeling through risk analysis of project activities is very useful for optimizing the schedules of activities using Critical Path Method and managing the scheduling control of NPP project. This study has shown new approach to optimal scheduling of NPP project, however, this does not consider the characteristic of activities according to the NPP site conditions. Hence, this study needs more research considering those factors.

  19. Investigation of k-struvite formation in magnesium phosphate cements

    OpenAIRE

    LE ROUZIC, Mathieu; Chaussadent, Thierry; Stefan, Lavinia; PLATRET, Gérard

    2014-01-01

    Magnesium phosphate cements can be used as an alternative of Portland cements for the stabilization/solidification (S/S) process of specific wastes like mercury, lead, … These cements are based on the reaction between magnesium oxide (MgO) and monopotassium phosphate (KH2PO4) mixed with water which leads to the formation of the solid skeleton of the matrix: MgO + KH2PO4 + 5H2O  MgKPO4.6H2O. The development of k-struvite crystals (MgKPO4.6H2O) leads to the setting of these ...

  20. Utilization of waste tires as alternative fuel in cement plant

    OpenAIRE

    2016-01-01

    Cement industry is regulated by legislation in which various measures are specified for prevention and reduction of air pollution as well as protection of human health, due to atmospheric emissions, which occur during cement production. Legislation also holds emission limit values for co-incineration of wastes i.e. alternative fuels. Waste tires as an alternative fuel can be co-incinerated i.e. co-processed in cement plants, where the high calorific value of the rubber is used to substitute f...

  1. Pavement management and rehabilitation of portland cement concrete pavements

    Science.gov (United States)

    Zegeer, C. V.; Agent, K. R.; Rizenbergs, R. L.; Curtayne, P. C.; Scullion, T.; Pedigo, R. D.; Hudson, W. R.; Roberts, F. L.; Karan, M. A.; Haas, R.

    Pavement management and rehabilitation projects and techniques are discussed. The following topics are discussed: economic analyses and dynamic programming in resurfacing project selection; implementation of an urban pavement management system; pavement performance modeling for pavement management; illustration of pavement management: from data inventory to priority analysis; rehabilitation of concrete pavements by using portland cement concrete overlays; pavement management study: Illinois tollway pavement overlays; resurfacing of plain jointed-concrete pavements; design procedure for premium composite pavement; model study of anchored pavement; prestressed concrete overlay at O'Hare International Airport: in-service evaluation; and, bonded portland cement concrete resurfacing.

  2. Developing 21st Century Process Skills through Project Design

    Science.gov (United States)

    Yoo, Jeong-Ju; MacDonald, Nora M.

    2014-01-01

    The goal of this paper is to illustrate how the promotion of 21st Century process skills can be used to enhance student learning and workplace skill development: thinking, problem solving, collaboration, communication, leadership, and management. As an illustrative case, fashion merchandising and design students conducted research for a…

  3. An Integrated Course and Design Project in Chemical Process Design.

    Science.gov (United States)

    Rockstraw, David A.; And Others

    1997-01-01

    Describes a chemical engineering course curriculum on process design, analysis, and simulation. Includes information regarding the sequencing of engineering design classes and the location of the classes within the degree program at New Mexico State University. Details of course content are provided. (DDR)

  4. Intensification of the Learning Process: Project Description. A Series of Reports Designed for Classroom Use.

    Science.gov (United States)

    Bucks County Public Schools, Doylestown, PA.

    The Personalizing Educational Prescriptions (PEP) Project has two main objectives: (1) the improvement of the diagnostic process with emphasis on the development of personalized educational prescriptions for all pupils; and (2) the improvement and expansion of multimedia services for all pupils. This report describes project goals, approaches, and…

  5. 75 FR 16820 - Delegated Processing for Certain 202 Supportive Housing for the Elderly Projects

    Science.gov (United States)

    2010-04-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT Delegated Processing for Certain 202 Supportive Housing for the Elderly Projects... 202 Supportive Housing for the Elderly projects. OMB Approval Number: 2502-New. Form Numbers:...

  6. The Interplay Between Evidence and Judgment in the IT Project Prioritization Process

    DEFF Research Database (Denmark)

    Shollo, Arisa; Constantiou, Ioanna; Kreiner, Kristian

    2015-01-01

    Strategic decisions concerning IT investments are based on a project prioritization process designed to accommodate evidence-based management and rational decision-making. Our empirical study of IT project prioritization in a financial institution shows how managers reach decisions under norms...

  7. Enabling Project-Centred Learning through Flexible Processes: The Cooper Experience

    NARCIS (Netherlands)

    Ceri, Stefano; Florian, Daniel; Matera, Maristella; Raffio, Alessandro; Spoelstra, Howard

    2007-01-01

    Ceri, S., Daniel, F., Matera, M., Raffio, A., Spoelstra, H. (2007, September). Enabling Project-Centered Learning through Flexible Processes: the COOPER Experience. Presentation given at the 1st International Workshop on Collaborative Open Environments for Project-Centered Learning, Crete, Greece.

  8. Enabling Project-Centred Learning through Flexible Processes: the COOPER Experience

    NARCIS (Netherlands)

    Ceri, Stefano; Daniel, Florian; Matera, Maristella; Raffio, Alessandro; Spoelstra, Howard

    2007-01-01

    Ceri, S., Daniel, F., Matera, M., Raffio, A., Spoelstra, H. (2007, September). Enabling Project-Centered Learning through Flexible Processes: the COOPER Experience. Paper presented at the 1st International Workshop on Collaborative Open Environments for Project-Centered Learning, Crete, Greece.

  9. The Studies of the Welding Processes and Procedures on the West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    SuiYongli; HuangFuxiang; ZhaoHaihong; YinChanghua

    2004-01-01

    The West-East pipeline project attracted the attention from all over the world for its long distance, huge diameter, complex geographic conditions, and diversified welding techniques being applied. In this paper the detail welding process and procedures used in the project are discussed and the distinguished achievements on welding techniques of China pipeline construction are described.

  10. Diagraphies de cimentation : vers une analyse de la qualité du contact ciment-formation Cement Logging: Toward an Analysis of the Quality of Cement-Formation Bonding

    Directory of Open Access Journals (Sweden)

    Isambourg P.

    2006-11-01

    specialists (VDL tool. The greatest progress that could be made with cementing logs was to detect defects in the cement-formation interface. This is what we have done within the framework of a project financed by ARTEP (Association de Recherche sur les Techniques d'Exploitation du Pétrole, made up of Total, Gaz de France (GDF, Institut Français du Pétrole (IFP and Elf Aquitaine Production (EAP. Laboratory experiments performed in the Fluid Analysis Service at Boussens involved the injecting of cement between a casing and a simulated formation, with or without the presence of mud having varying thicknesses. Fast or slow formations as well as fast or slow cements were used. The ultrasonic echoes obtained by a ceramic CET sonde were recorded and analyzed. Both theory and the experiments showed that ultrasonic echoes are modified in the presence of mud and/or gas. The relations between the shape of the ultrasonic wave and presence of mud and gas between the cement and the formation were determined. A processing procedure is proposed with its limitations. Cementing Quality : If we had to set forth a quality criterion for cementing, we would say: For cementing to be considered as being of good quality, the cement sheath must be at least as leakproof as the formation it replaces. When a borehole is drilled, different zones are effectively brought into communication. The initial isolation will be established by the casing + cement sheath. This function will thus be correctly ensured if this combination lets pass only the start of a fluid leak (water, oil, gas that is less than or equal to what is allowed by an equivalent section of formation drilled through. Naturally, this concept is mainly applied to sensitive zones, e. g. such as the overburden of a reservoir. However, it should be noted that this concept is also applied to the reservoir itself and not only to the overburden. Indeed, a leaky cement sheath at the level of a reservoir with relatively low permeability could, for

  11. Energy Efficiency Improvement Opportunities for the Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-31

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

  12. The Characteristics and the Countermeasures of the Occupational Hazards for New Dry Process Cement Production Line%新型干法水泥生产线职业危害特点及防治对策

    Institute of Scientific and Technical Information of China (English)

    王超洋; 秦文华

    2013-01-01

      为探讨新型干法水泥生产工艺的职业病危害因素的特点,并提出相应的防治对策,选取某企业5000 t/d新型干法水泥熟料生产线为代表,对其工作场所中存在的职业病危害因素进行识别,并对该规模下职业病危害因素的浓度或强度进行检测.结果表明,粉尘和噪声为该工艺的主要职业病危害因素,其岗位达标率分别为60%和51.5%,毒物及工频电场等均满足职业卫生标准限值的要求.根据职业危害的关键控制岗位,提出防治对策以减少职业病发生.%  For discussing the characteristics of the occupational hazards for new dry process cement production line, and advancing the corresponding countermeasures,the authors select a company with the production of 5000 t/d new dry process cement as the representative,identify the factors of occupational hazards in workplace and detect the concentration or intensity of occupational hazards. The results show that dust and noise are the major occupational hazards in the process,the post compliance rates were 60% and 51.5%. The poison and power frequency electric field,etc. meet the requirements of occupational health standard limits. According to the occupational hazards of critical control positions,the control measures for reducing occupational diseases is put forward.

  13. Hidration kinetics study of tlie mixed cements

    Directory of Open Access Journals (Sweden)

    Duque Fernández, Gabriel . L

    1993-09-01

    Full Text Available A study of the hydration process of cements with 10% and 20% addition of a tuff from "Las Carolinas" quarry (Cienfuegos, Cuba by different methods was done. The results obtained by different methods showed a good agreement. It was proved an increment of the hydration products, an acceleration of alite hydration and a swelling of the fixed water in mixed cements. The resistance of the cement with 10% addition is similar to that of the pure cement for ages of 28 days, whereas with 20% addition they were similar only after 180 days.

    Se hizo un estudio por diferentes métodos de la hidratación de cementos con 10% y 20% de adición de una toba del yacimiento "Las Carolinas", en la provincia de Cien fuegos (Cuba. Hubo una buena correspondencia entre las diferentes técnicas de análisis utilizadas, comprobándose que en los cementos mezclados se incrementan los productos de hidratación, se acelera la hidratación de la alita, aumenta el contenido de agua fija, así como que la resistencia del cemento, con hasta 10% de adición, es similar al cemento puro para tiempos de curado de 3 y 28 días, mientras que con 20% de adición sólo se igualan después de los 180 días.

  14. Kinetics of strength gain of biocidal cements

    Directory of Open Access Journals (Sweden)

    Rodin Aleksandr Ivanovich

    Full Text Available Biocorrosion becomes the determinative durability factor of buildings and constructions. Damages of construction materials caused by bacteria, filamentous fungi, actinomycetes constitute a serious danger to the constructions of a building or a structure and to the health of people. Biodeteriorations are typical both in old and new constructions. A great quantity of destruction factors of industrial and residential buildings under the influence of microorganisms was established in practice. Providing products and constructions based on concretes fungicidal and bactericidal properties is an important direction of modern construction material science. The most efficient way to solve this task is creation of biocidal cements. The article presents the results of experimental studies of kinetic dependences of strength gain by biocidal cements by physico-mechanical and physico-chemical analysis methods. The identical velocity character of initial hydration of the developed compositions of biocidal cements is set, as well as a more calm behavior of hardening processes at later terms. It has been established that the compositions of biocidal cements modified by sodium sulfate and sodium fluoride possess the greatest strength.

  15. Thermal/Heat Transfer Analysis Using a Graphic Processing Unit (GPU) Enabled Computing Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this project was to use GPU enabled computing to accelerate the analyses of heat transfer and thermal effects. Graphical processing unit (GPU)...

  16. Process-Hardened, Multi-Analyte Sensor for Characterizing Rocket Plum Constituents Under Test Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project aims to develop a process-hardened, simple and low cost multi-analyte sensor for detecting components of rocket engine plumes. The sensor will be...

  17. Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard 3.8 kW silicon carbide (SiC) Power Processing Unit (PPU) for Hall Effect...

  18. Foaming in Hanford River Protection Project Waste Treatment Plant LAW Evaporation Processes - FY01 Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Calloway, T.B.

    2002-07-23

    The LAW evaporation processes currently being designed for the Hanford River Protection Project Waste Treatment Plant are subject to foaming. Experimental simulant studies have been conducted in an effort to achieve an effective antifoam agent suitable to mitigate such foaming.

  19. GENERAL ALGORITHMIC SCHEMA OF THE PROCESS OF THE CHILL AUXILIARIES PROJECTION

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The general algorithmic diagram of systematization of the existing approaches to the process of projection is offered and the foundation of computer system of the chill mold arming construction is laid.

  20. Largest domestic tungsten and molybdenum deep processing project finding its home in Luan-chuan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Recently, a tungsten and molybdenum deep processing project was formally executed with a joint investment of 300 million yuan from Luanchuan Molybdenum Mining & Smelting Co., Ltd, Beijing Tian-Long Tungsten & Mo-

  1. Improvement of the Biogas Production Process : Explorative project (EP1)

    OpenAIRE

    Karlsson, Anna; Björn, Annika; Sepehr, Shakeri Yekta; Svensson, Bo

    2014-01-01

    There are several ways to improve biogas production in anaerobic digestion processes and a number of strategies may be chosen. Increased organic loading in existing plants will in most cases demand the introduction of new substrate types. However, to substantially increase the Swedish biogas production new, large-scale biogas plants digesting new substrate types need to be established. Better utilization of existing digester volumes can be linked to:  Increase of organic loading rates and/or ...

  2. Improving Packet Processing Performance in the ATLAS FELIX Project

    CERN Document Server

    Schumacher, Jorn; The ATLAS collaboration; Borga, Andrea; Boterenbrood, Hendrik; Chen, Hucheng; Chen, Kai; Drake, Gary; Francis, David; Gorini, Benedetto; Lanni, Francesco; Lehmann Miotto, Giovanna; Levinson, Lorne; Narevicius, Julia; Roich, Alexander; Ryu, Soo; Schreuder, Frans Philip; Vandelli, Wainer; Zhang, Jinlong; Vermeulen, Jos

    2015-01-01

    Experiments in high-energy physics (HEP) and related fields often impose constraints and challenges on data acquisition systems. As a result, these systems are implemented as unique mixtures of custom and commercial-off-the-shelf electronics (COTS), involving and connecting radiation-hard devices, large high-performance networks, and computing farms. FELIX, the Frontend Link Exchange, is a new PC-based general purpose data routing device for the data-acquisition system of the ATLAS experiment at CERN. Performance is a very crucial point for devices like FELIX, which have to be capable of processing tens of gigabyte of data per second. Thus it is important to understand the performance limitations for typical workloads on modern hardware. We present an analysis of a packet processing algorithm that is used in FELIX, and show how the PC system's memory architecture plays a key factor in the overall data throughput achieved by the application. Finally, we present optimizations that increase the processing throug...

  3. UTILIZATION OF AGARWOOD DISTILLATION WASTE IN OILWELL CEMENT AND ITS EFFECT ON FREE WATER AND POROSITY

    Directory of Open Access Journals (Sweden)

    Arina Sauki

    2013-10-01

    Full Text Available The intent of this research is to utilize the waste produced by distillation process of Agarwood oil and convert it into a profitable oilwell cement additive. Common problem during oilwell cementing is free wáter separation. This problem could weaken cement at the top, gas migration problem and non uniform density of cement slurry that are even worst in cementing deviated well. Another concern on cementing design is the porosity of the hardened cement. If the cement is too porous, it can lead to gas migration and casing corrosion. All tests were conducted according to API Specification-10B. Free water test was determined at different concentrations of Agarwood Waste Additive (AWA, different inclination angles and different temperatures. Based on the findings, it was observed that zero free water was produced when 2% BWOC of AWA was used at all angles. The findings also revealed that AWA can maintain good thermal stability as it could maintain zero free water at increased temperature up to 60˚C.  The porosity of AWA cement was comparable with standard API neat cement as the porosity did not differ much at 2% BWOC of AWA. Therefore, it can be concluded that the AWA is suitable to  be used as an additive in oil well cement (OWC  with 2% BWOC is taken as the optimum concentration.

  4. Advances in Glass Ionomer Cements

    OpenAIRE

    KAYA, Dt. Tuğba; TİRALİ, Yard. Doç. Dr. Resmiye Ebru

    2013-01-01

    In recent years there have been a number of innovations and developments with respect to glass ionomer cements and their applications in clinical dentistry. This article considers some of the recent outstanding studies regarding the field of glass ionomer cement applications, adhesion and setting mechanisms, types, advantage and disadvantages among themselves and also to enhance the physical and antibacterial properties under the title of 'Advances in Glass Ionomer Cements'. As their biologic...

  5. Cement penetration after patella venting.

    Science.gov (United States)

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

    2009-01-01

    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 non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

  6. Improving the CO2 performance of cement, part III : The relevance of industrial symbiosis and how to measure its impact

    OpenAIRE

    2015-01-01

    Cement production contributes to extensive CO2 emissions. However, the climate impact can vary significantly between different production systems and different types of cement products. The market is dominated by ordinary Portland cement, which is based on primary raw materials and commonly associated with combustion of vast amounts of fossil fuels. Therefore, the production of Portland cement can be described as a rather linear process. But there are alternative options, for example, involvi...

  7. A genetic fuzzy analytical hierarchy process based projection pursuit method for selecting schemes of water transportation projects

    Science.gov (United States)

    Jin, Juliang; Li, Lei; Wang, Wensheng; Zhang, Ming

    2006-10-01

    The optimal selection of schemes of water transportation projects is a process of choosing a relatively optimal scheme from a number of schemes of water transportation programming and management projects, which is of importance in both theory and practice in water resource systems engineering. In order to achieve consistency and eliminate the dimensions of fuzzy qualitative and fuzzy quantitative evaluation indexes, to determine the weights of the indexes objectively, and to increase the differences among the comprehensive evaluation index values of water transportation project schemes, a projection pursuit method, named FPRM-PP for short, was developed in this work for selecting the optimal water transportation project scheme based on the fuzzy preference relation matrix. The research results show that FPRM-PP is intuitive and practical, the correction range of the fuzzy preference relation matrix A it produces is relatively small, and the result obtained is both stable and accurate; therefore FPRM-PP can be widely used in the optimal selection of different multi-factor decision-making schemes.

  8. A Genetic Fuzzy Analytical Hierarchy Process Based Projection Pursuit Method for Selecting Schemes of Water Transportation Projects

    Institute of Scientific and Technical Information of China (English)

    JIN Juliang; LI Lei; WANG Wensheng; ZHANG Ming

    2006-01-01

    The optimal selection of schemes of water transportation projects is a process of choosing a relatively optimal scheme from a number of schemes of water transportation programming and management projects, which is of importance in both theory and practice in water resource systems engineering. In order to achieve consistency and eliminate the dimensions of fuzzy qualitative and fuzzy quantitative evaluation indexes, to determine the weights of the indexes objectively, and to increase the differences among the comprehensive evaluation index values of water transportation project schemes, a projection pursuit method, named FPRM-PP for short, was developed in this work for selecting the optimal water transportation project scheme based on the fuzzy preference relation matrix. The research results show that FPRM-PP is intuitive and practical, the correction range of the fuzzy preference relation matrix A it produces is relatively small, and the result obtained is both stable and accurate; therefore FPRM-PP can be widely used in the optimal selection of different multi-factor decision-making schemes.

  9. Collaborative Project: Improving the Representation of Coastal and Estuarine Processes in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frank [Univ. of Washington, Seattle, WA (United States); Dennis, John [Univ. of Washington, Seattle, WA (United States); MacCready, Parker [Univ. of Washington, Seattle, WA (United States); Whitney, Michael [Univ. of Washington, Seattle, WA (United States)

    2016-10-20

    This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation.

  10. West Valley demonstration project: alternative processes for solidifying the high-level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Holton, L.K.; Larson, D.E.; Partain, W.L.; Treat, R.L.

    1981-10-01

    In 1980, the US Department of Energy (DOE) established the West Valley Solidification Project as the result of legislation passed by the US Congress. The purpose of this project was to carry out a high level nuclear waste management demonstration project at the Western New York Nuclear Service Center in West Valley, New York. The DOE authorized the Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute, to assess alternative processes for treatment and solidification of the WNYNSC high-level wastes. The Process Alternatives Study is the suject of this report. Two pretreatment approaches and several waste form processes were selected for evaluation in this study. The two waste treatment approaches were the salt/sludge separation process and the combined waste process. Both terminal and interim waste form processes were studied.

  11. Embodied energy in cement stabilised rammed earth walls

    Energy Technology Data Exchange (ETDEWEB)

    Venkatarama Reddy, B.V.; Prasanna Kumar, P. [Department of Civil Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2010-03-15

    Rammed earth walls are low carbon emission and energy efficient alternatives to load bearing walls. Large numbers of rammed earth buildings have been constructed in the recent past across the globe. This paper is focused on embodied energy in cement stabilised rammed earth (CSRE) walls. Influence of soil grading, density and cement content on compaction energy input has been monitored. A comparison between energy content of cement and energy in transportation of materials, with that of the actual energy input during rammed earth compaction in the actual field conditions and the laboratory has been made. Major conclusions of the investigations are (a) compaction energy increases with increase in clay fraction of the soil mix and it is sensitive to density of the CSRE wall, (b) compaction energy varies between 0.033 MJ/m{sup 3} and 0.36 MJ/m{sup 3} for the range of densities and cement contents attempted, (c) energy expenditure in the compaction process is negligible when compared to energy content of the cement and (d) total embodied energy in CSRE walls increases linearly with the increase in cement content and is in the range of 0.4-0.5 GJ/m{sup 3} for cement content in the rage of 6-8%. (author)

  12. PHYSICO-CHEMICAL MODIFICATION OF MONOLITHIC CONCRETE CEMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    D. V. Rudenko

    2015-10-01

    Full Text Available Purpose. The paper is aimed to the development of scientific bases of the technology of modified concrete of new generation for special facilities by managing the processes of structure formation of modified cement system in conditions of hardening. Methodology. For the achievement the goal: 1 the research of rheological characteristics of modified concrete mixes for special facilities purpose and processes of structure formation of modified cement system of natural curing concrete was conducted; 2 there were defined methods of reliable evaluation of concrete strength at the removal time of formwork and transmission of loads to the constructions where the concrete has not reached the designed strength. Findings. The author found that the structure formation process develops in the hydrating modified cement system as a result of interaction of various macroions. In this process its active parts prevail, which considerably exceed its dissipative part compared to normal conditions of hardening. Originality. There were established the regularities of structure formation of modified cement system, reinforced with synthesized, well crystallized helical filamentary crystals, mechanical grip of which is considered as a principal source of strength in combination with an additional coupling achieved due to cross-germination of crystals. Practical value. In the study the increased binding capacity of cement in high strength concretes and the use of modified cement systems in the special conditions of concreting were considered. The organo-mineral modifying complex that provides the dispersed reinforcement of concrete cement matrix which allows modifying the process of cement matrix structure formation by changing the nature of the surface of binder and modifier was developed. The temperature factor has no negative influence on the hardening concrete and complex modifier provides the improved physico-mechanical characteristics of cement matrix and concrete

  13. Combustion of solid alternative fuels in the cement kiln burner

    DEFF Research Database (Denmark)

    Nørskov, Linda Kaare

    In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... modelling, data collection and observations at an industrial cement plant firing alternative fuels. Alternative fuels may differ from conventional fossil fuels in combustion behaviour through differences in physical and chemical properties and reaction kinetics. Often solid alternative fuels are available...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-22

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

  15. Signal Processing System for the CASA Integrated Project I Radars

    Energy Technology Data Exchange (ETDEWEB)

    Bharadwaj, Nitin; Chandrasekar, V.; Junyent, Francesc

    2010-09-01

    This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation of range velocity ambiguity. The operational waveform is designed based on operational requirements and system/hardware requirements. A dual Pulse Repetition Frequency (PRF) waveform was developed and implemented for the first generation X-band radars deployed by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This paper presents an evaluation of the performance of the waveforms based on simulations and data collected by the first-generation CASA radars during operations.

  16. Resistance Factors in the Implementation of Software Process Improvement Project in Malaysia

    Directory of Open Access Journals (Sweden)

    Mohd H.N.M. Nasir

    2008-01-01

    Full Text Available For the past two decades, improving the quality of software has become an important agenda in the software industries as they have been assessed according to standards such as the CMM, CMM-I, ISO 9000 SIX-SIGMA and etc. As the result, software process improvement project implementations have been the main targets by most software companies. However, many initiatives are facing variety of problems and difficulties due to lack of guidance and experience. Hence, this research attempted to identify and analyze main resistance factors which influenced the implementation of the software process improvement project specifically companies operated in Malaysia including local and multi-national companies. The findings helped other software companies to manage future projects through the use of preventive actions or proper planning which intended to lessen anticipated problems during software process improvement projects implementation. This research used a survey instrument to gather data from 29 companies operated across Malaysia with the total of 174 business and software professionals responded. Average of 4 to 8 questionnaires were distributed to each company with the objective of getting wider views on each SPI project. The questionnaires were mainly distributed to professionals who are directly involved in SPI projects. The results showed that the most critical resistance factor is lack of adhesion and participation of the entire individual involved in SPI projects. This result is similar with the result gained by Brietzke and Rabello which they have conducted it in Brazil and corroborated the research findings experience in SPI project.

  17. Penetration of natural gas in industrial processes for direct burning: the case of ceramics, cement and glass industries; Penetracao do gas natural em processos industriais de queima direta: caso das industrias ceramica, cimento e vidro

    Energy Technology Data Exchange (ETDEWEB)

    Berni, Mauro Donizeti; Leite, Alvaro A. Furtado [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Dorileo, Ivo Leandro [Universidade Federal do Mato Grosso (NIEPE/UFMT), Cuiaba, MT (Brazil). Nucleo Interdisciplinar de Estudos em Planejamento Energetico; Bajay, Sergio Valdir [Universidade estadual de Campinas (FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Energia], e-mail: bajay@fem.unicamp.com.br

    2008-07-01

    Industrial sector can use the natural gas (NG) as raw material, as fuel and in co-generation. The NG as fuel is used, predominantly, to produce heat in the Brazilian industries. That rate, both main forms of industrial use of the NG are its direct burning in kilns - when the direct contact is had with the product - and the supply of process heat through boilers, for instance. Direct burning is used in the ceramic, cement and glass industries. This work discuss the penetration opportunity of the NG in the direct burning regarding the fuel oil and other energy that it can substitute, the environmental effects and the co-generation possibilities in each one of the analyzed industrial blanches in this work. (author)

  18. ICT and mobile health to improve clinical process delivery. a research project for therapy management process innovation.

    Science.gov (United States)

    Locatelli, Paolo; Montefusco, Vittorio; Sini, Elena; Restifo, Nicola; Facchini, Roberta; Torresani, Michele

    2013-01-01

    The volume and the complexity of clinical and administrative information make Information and Communication Technologies (ICTs) essential for running and innovating healthcare. This paper tells about a project aimed to design, develop and implement a set of organizational models, acknowledged procedures and ICT tools (Mobile & Wireless solutions and Automatic Identification and Data Capture technologies) to improve actual support, safety, reliability and traceability of a specific therapy management (stem cells). The value of the project is to design a solution based on mobile and identification technology in tight collaboration with physicians and actors involved in the process to ensure usability and effectivenes in process management.

  19. By-product materials in cement clinker manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gadayev, A. [ICS and E, Aurora, CO (United States); Kodess, B. [VNIIMS Gosstandart of Russia, Moscow (Russian Federation)

    1999-02-01

    The use of Cl- and SO{sub 3}-containing by-products from chemical industries for manufacturing Portland cement clinker using a wet process was examined. The chemical and mineralogical compositions of the by-products and raw materials were determined. Homogeneous raw mixes containing different concentrations of by-products (5--30%) were prepared and the influence of the by-products on all steps of burning the mixes in a kiln to form a cement clinker was investigated. It was shown that introducing Cl- and SO{sub 3}-containing by-products to the raw mixes significantly changes all the cement clinker producing stages and changes the chemical and mineralogical compositions at all intermediate stages and in the finished products, forming new minerals containing Cl and SO{sub 3} [CaO{sub x} (SiO{sub 2}){sub y} CaCl{sub 2}] or [CaO{sub x} (SiO{sub 2}){sub y} CaSO{sub 4}] and increasing the amount of well-known intermediate minerals. The presence of the chlorides and sulfates in the cement clinker burning processes removes alkali from the raw mixes, turning them to volatile forms, accelerating the raw mineral decomposition processes and accelerating the formation processes of cement minerals (C{sub 2}S, C{sub 12}A{sub 7}, C{sub 4}AF) and formation of chloride and sulfate cycles in the kiln, forming clinker liquids and decreasing the formation and growth of the main cement minerals (C{sub 3}A, C{sub 3}S). The cement clinker contains some quantity of minerals with Cl or SO{sub 3}. Their presence in the final product decreases cement quality by reducing the amount of active CaO (C) and reducing the active CaO/SiO{sub 2} ratio.

  20. Modeling of Pulverized Coal Combustion in Cement Rotary Kiln

    OpenAIRE

    2006-01-01

    In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rot...

  1. Ionic modification of calcium phosphate cement viscosity. Part II: hypodermic injection and strength improvement of brushite cement.

    Science.gov (United States)

    Barralet, J E; Grover, L M; Gbureck, U

    2004-05-01

    Brushite-forming calcium phosphate cements are of great interest as bone replacement materials because they are resorbable in physiological conditions. However, their short setting times, low mechanical strengths and limited injectability limit broad clinical application. In this study, we showed that a significant improvement of these properties of brushite cement could be achieved by the use of sodium citrate or citric acid as setting retardants, such that workable cement pastes with a powder to liquid ratio of up to 5 could be manufactured. The cement used in this study consisted of an equimolar powder mixture of beta-tricalcium phosphate and monocalcium phosphate hydrate The use of 500 mM-1M retardant solutions as liquid phase enabled initial setting times of 8-12 min. Wet compressive strength were found to be in the range between 12-18 MPa after immersion of uncompacted cement samples in serum for 24 h. A further strength improvement to 32 MPa was obtained by compaction of the cement paste during samples preparation. This is significant because high-temperature processes cannot be used to fabricate hydrated calcium phosphate materials. Cement pastes were injectable through a hypodermic needle at a powder to liquid ratio of 3.3 g/ml when a 1M citric acid was used as liquid phase, thus enabling precise controlled delivery to small defects.

  2. Processamento de concretos refratários zero-cimento contendo alumina e microssílica Processing of zero-cement refractory castables containing alumina and microsilica

    Directory of Open Access Journals (Sweden)

    P. Bonadia Neto

    2000-03-01

    Full Text Available Os concretos auto-escoantes de reduzido teor de cimento aliam facilidade de aplicação a um bom desempenho em temperaturas elevadas. Estudos anteriores mostraram que a auto-escoabilidade e o empacotamento de partículas necessário para redução do teor de cimento são função da granulometria e do estado de dispersão da matriz do concreto. Bonadia e outros propuseram, então, uma metodologia de formulação de concretos baseada nestes dois conceitos, enfocando a otimização dos parâmetros granulométricos. Com a granulometria otimizada, Studart et al. geraram mapas de estabilidade, que fornecem as condições ideais para dispersão de uma matriz contendo apenas alumina. Com o auxílio destes mapas foi possível preparar concretos auto-escoantes isentos de cimento (zero-cimento. Devido à importância da microssílica como precursora da fase mulita no concreto, o objetivo deste trabalho foi gerar mapas de estabilidade para matrizes contendo alumina e microssílica. Os resultados mostraram uma correlação entre a fluidez dos concretos e as regiões de menor viscosidade e tensão de escoamento indicadas nos mapas.Low and ultra-low cement self-flow castables combine good high temperature performance and faster application rate. It has been shown that the castable self-flow ability and packing is a function of its particle size distribution and matrix rheological conditions. Bonadia and others proposed a castable formulation methodology based on these two concepts, focusing mainly the particle size distribution parameters. Stability maps, which predict the ideal matrix dispersion conditions, were generated by Studart et al. for aluminous castables in order to complete the proposed methodology. Such maps allowed the preparation of self-flow zero-cement (without any hydraulic binder castables compatible with industrial applications. Since microsilica is essential for mullite formation in castables, the main objective of this work is to generate

  3. Interaction of cerium and calcium-enriched phase in the preparation process of YG6 cemented carbide%铈与YG6硬质合金制备过程中富钙相的交互作用

    Institute of Scientific and Technical Information of China (English)

    何文; 谭敦强; 朱红波; 邝海; 欧阳国霞

    2016-01-01

    在硬质合金的原材料仲钨酸铵(APT)粉末中添加Ca和稀土Ce元素,探讨稀土Ce元素与硬质合金制备过程中富钙相的交互作用。材料的物相组成、显微结构及成分分别通过X射线衍射仪、扫描电子显微镜及能谱进行检测与分析。结果表明:氧化钨还原过程中会产生CaWO4和Ca4.26W10O30两种富钙相,分布在钨颗粒内部和周围,使钨颗粒的棱角钝化,碳化后富钙相转变为Ca4.26W10O30和CaC2相,富钙相可急剧降低YG6硬质合金的性能;添加适量稀土Ce可降低富钙相对钨粉的影响,钨粉颗粒的棱角变得明显,颗粒尺寸变小且分布均匀,稀土Ce与富钙相发生反应生成Ce0.9Ca0.1O1.9三元相;稀土Ce与富钙相的交互作用效果显著,与1% Ca-YG6硬质合金相比,1% Ce+1% Ca-YG6硬质合金的致密度、硬度和断裂韧性分别提高了7.8%,34.3%和67.8%。%The elements of Ca and rare earth Ce were added in APT powder. The interaction of rare earth element Ce with calcium-enriched phase was discussed during the preparation process of cemented carbide. The phase composition, microstructure and element distribution were tested by using X-ray diffractometer, scanning electron microscope and energy disperse spectroscopy, respectively. The results show that two kinds of calcium-enriched phases, CaWO4 and Ca4.26W10O30, are generated in the process of reducing tungsten oxide, which passivate tungsten particles. After carburization, calcium-enriched phases transform into the Ca4.26W10O30 and CaC2 phases. Calcium-enriched phases can sharply reduce the property of YG6 cemented carbide. Adding a moderate amount of rare earth Ce can decrease the influence of calcium-enriched phases on tungsten particles. The edges and corners of tungsten particles become more obvious, and the particle size of tungsten powders becomes smaller and uniform. During carburization process, rare earth Ce reacts with calcium-enriched phase and forms

  4. Power Processing for a Conceptual Project Prometheus Electric Propulsion System

    Science.gov (United States)

    Scina, Joseph E., Jr.; Aulisio, Michael; Gerber, Scott S.; Hewitt, Frank; Miller, Leonard; Elbuluk, Malik; Pinero, Luis R. (Technical Monitor)

    2005-01-01

    NASA has proposed a bold mission to orbit and explore the moons of Jupiter. This mission, known as the Jupiter Icy Moons Orbiter (JIMO), would significantly increase NASA s capability to explore deep space by making use of high power electric propulsion. One electric propulsion option under study for JIMO is an ion propulsion system. An early version of an ion propulsion system was successfully used on NASA's Deep Space 1 mission. One concept for an ion thruster system capable of meeting the current JIMO mission requirement would have individual thrusters that are 16 to 25 kW each and require voltages as high as 8.0 kV. The purpose of this work is to develop power processing schemes for delivering the high voltage power to the spacecraft ion thrusters based upon a three-phase AC distribution system. In addition, a proposed DC-DC converter topology is presented for an ion thruster ancillary supply based upon a DC distribution system. All specifications discussed in this paper are for design convenience and are speculative in nature.

  5. Providing a framework to improve the performance of business process management projects based on BPMN

    Directory of Open Access Journals (Sweden)

    Mojtaba Ahmadi

    2016-01-01

    Full Text Available Modeling of business processes, based on Business Process Modeling Notation (BPMN, helps analysts and managers to understand business processes, and, identify their shortages. These models provide a context to make rational decision of organizing business processes activities in an understandable manner. The purpose of this paper is to provide a framework for better understanding of business processes and their problems by reducing the cognitive load of displayed information for their audience at different managerial levels while keeping the essential information which are needed by them. For this reason, we integrate business process diagrams across the different managerial levels to develop a framework to improve the performance of business process management (BPM projects. This framework, which is referred to as “Business Process Improvement Framework Based on Managerial Levels (BPIML” in this paper, considers three levels of management (Organizational level managers, Process /Departmental level managers and Activity level managers for manager of an organization. Then, defines certain types of models based on BPMN, for each management level, by taking into the account the objectives and tasks of various managerial levels in organizations and their role in Business Process Management (BPM projects. This framework will make us able to provide the necessary support for making decisions about business processes. The framework is evaluated with a case study in a real business process improvement project, to demonstrate its superiority over the conventional method. A questionnaire consisted of 10 questions using Likert scale was designed and given to the participants (three managerial levels. The results of this questionnaire suggested that, managers and senior experts of the organization considered utilization of the proposed framework improving for implementation of BPM projects and provide support for correct and timely decisions by

  6. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-01

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

  7. Phosphate based oil well cements

    Science.gov (United States)

    Natarajan, Ramkumar

    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 that is being used presently has several shortcomings for borehole sealant. The setting of the Portland cement in permafrost regions is poor because the water in it will freeze even before the cement sets and because of high porosity and calcium oxide, a major ingredient it gets easily affected by the down hole gases such as carbon dioxide. The concept of phosphate bonded cements was born out of considerable work at Argonne National Laboratory (ANL) on their use in stabilization of radioactive and hazardous wastes. Novel cements were synthesized by an acid base reaction between a metal oxide and acid phosphate solution. The major objective of this research is to develop phosphate based oil well cements. We have used thermodynamics along with solution chemistry principles to select calcined magnesium oxide as candidate metal oxide for temperatures up to 200°F (93.3°C) and alumina for temperatures greater than 200°F (93.3°C). Solution chemistry helped us in selecting mono potassium phosphate as the acid component for temperatures less than 200°F (93.3°C) and phosphoric acid solution greater than 200°F (93.3°C). These phosphate cements have performance superior to common Portland well cements in providing suitable thickening time, better mechanical and physical properties.

  8. Decision Process Analysis on Project Priority Strategy: A Case Study of an ICT Design Firm

    Directory of Open Access Journals (Sweden)

    Vincent F. Yu

    2014-01-01

    Full Text Available Project priority strategy is the benchmarking of a corporate operation management strategy and in particular is used by a projects-based research and development firm in the complex competence environment of the information and communication technology (ICT industry. This research takes the variables of external environments and internal resources into account for a firm’s market, technology, and finance assets in order to present a decision process on a project priority strategy. This empirical study also addresses the key factors of the interaction between business on a project development’s supply chain: clients, the examined firm, and suppliers. The findings indicate that a profit-driven project can dominate the firm’s strategic operations and management from the resource-based view and analytic hierarchy process technique perspectives. At the same time, the analysis results contribute significant values to project decision management, which is highly recommended for small-medium enterprises conducting product/project development, project portfolio management, and strategic business management.

  9. 不同分解工艺下磷石膏分解制水泥熟料的LCA研究%LCA Study on the Preparation of Cement Clinker by the Phosphogypsum Decomposition Under Different Decomposition Process

    Institute of Scientific and Technical Information of China (English)

    张杭; 马丽萍; 胡建红; 毛宇; 戴取秀; 谢龙贵

    2013-01-01

    Phosphogypsum was a by-production of the production of wet phosphoric acid,which caused environmental pollution containing water and air pollution.The method of life cycle assessment was used to analyze the test method of circulating fluidized bed reduced and decomposed phosphogypsum to make cement clinker,and it was compared with the traditional method of rotary kiln.The results show that the impact of cement production on environmental load mainly reflected on the consumption of non-generation energy and non-reclaiming source,as well as green house effect.The test method which reduced the impact of the manufacturing process on the environment was proposed.%磷石膏是湿法磷酸生产过程中的副产品,大量的磷石膏废渣可引起水体和空气的环境污染,运用生命周期评价的方法,对循环流化床还原分解磷石膏制水泥熟料试验方法进行分析,并与传统的回转窑方法进行比较.研究结果表明,在工艺过程中的环境负荷主要体现在不可再生资源的消耗、不可再生能源的消耗和温室效应,所提出的试验方法较传统方法可减少工艺过程中对环境负荷的影响.

  10. Thermal analysis of cement pastes with superabsorbent polymers

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Jensen, Ole Mejlhede; Lukosiute, Irena

    2013-01-01

    Thermal analysis of cement systems is very helpful in the understanding of many different properties of cementitious compounds, both for the original reacting compounds, and also for the resulting hydration products. Superabsorbent polymers can be added to cement systems with many different reasons......, so it is relevant that fundamental knowledge of this new compound on the development of hydration is well understood [1-3]. This paper reports research on thermal analysis of cement pastes with superabsorbent polymers. We have studied several parameters: the concentration of SAP in the system......, the effect of particle size distribution, and their influence on the hydration process with focus on cement-silica systems. This is done at different thermodynamic conditions, so the energy of activation in the different systems can be accessed. This paper provides information relevant to hydration modelling...

  11. Reduction of soil pollution by usingwaste of the limestone in the cement industry

    Science.gov (United States)

    Muñoz, M. Cecilia Soto; Robles Castillo, Marcelo; Blanco Fernandez, David; Diaz Gonzalez, Marcos; Naranjo Lamilla, Pedro; Moore Undurraga, Fernando; Pardo Fabregat, Francisco; Vidal, Manuel Miguel Jordan; Bech, Jaume; Roca, Nuria

    2016-04-01

    In the cement manufacturing process (wet) a residue is generated in the flotation process. This builds up causing contamination of soil, groundwater and agricultural land unusable type. In this study to reduce soil and water pollution 10% of the dose of cement was replaced by waste of origin limestone. Concretes were produced with 3 doses of cement and mechanical strengths of each type of concrete to 7, 28 and 90 days were determined. the results indicate that the characteristics of calcareous residue can replace up to 10% of the dose of cement without significant decreases in strength occurs. It is noted that use of the residue reduces the initial resistance, so that the dose of cement should not be less than 200 kg of cement per m3. The results allow recommends the use of limestone waste since it has been observed decrease in soil and water contamination without prejudice construction material Keywords: Soil contamination; Limestone residue; Adding concrete

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

    Science.gov (United States)

    Duvallet, Tristana Yvonne Francoise

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

  13. Competitive and sustainable growth - new European research programmes (projects and actions concerning waste processing and recovery)

    Energy Technology Data Exchange (ETDEWEB)

    Adjemian, A. [European Commission, DG-RTD, Brussels (Belgium)

    2001-07-01

    Eco-efficient processes and design, production with zero waste, life cycle optimization and material recycling characterize the Fifth Framework Program of the European Union's Directorate General for Science, Research and Development. Some new projects under this Program, related to waste prevention and recovery are described. Workshops, conferences, international cooperation, networks, and virtual institutes are discussed to illustrate the process of program development. Major achievements in the field of liquid effluent processing, solid waste incineration, recycling, recovery and reuse of materials from waste, projects undertaken as part of the Forth Framework Program, which are now nearing completion, are also reviewed. 4 tabs.

  14. The PHARUS Project; Real Time Digital Processing of Airborne Polarimetric Radar Signals

    NARCIS (Netherlands)

    Pouwels, H.; Hoogeboom, P.; Koomen, P.J.; Snoeij, P.

    1992-01-01

    The Dutch PHARUS project aims for the developrlenÈ of a polarimetric C-band aircraft SAR, to be finalized in 1994. The PHARUS systen consists of three subsystens: the radar, the subsystem for the onboard data processing and recording and the ground-based subsystem for SAR processing. PHARUS is a ver

  15. Basalt Waste Isolation Project technical program evaluation process: A criteria-based method

    Science.gov (United States)

    Babad, H.; Evans, G. C.; Wolfe, B. A.

    The need to objectively evaluate the progress being made by the Basalt Waste Isolation Project (BWIP) toward establishing the feasibility of siting a nuclear waste repository in basalt (NWRB) mandates a process for evaluating the technical work of the project. To assist BWIP management in the evaluation process, the Systems Department staff has developed a BWIP Technical Program Evaluation Process (TPEP). The basic process relates progress on project technical work to the SWIP Functional and System Performance Criteria as defined in National Waste Terminal Storage (MWTS) Criteria Documents. The benefits of the TPEP to BWIP and future plans for TPEP are discussed. During fiscal year (FY) 1982, TPEP will be further formalized and further applied to the review of BWIP technical activities.

  16. Basalt Waste Isolation Project Technical Program Evaluation Process: a criteria-based method

    Energy Technology Data Exchange (ETDEWEB)

    Babad, H.; Evans, G.C.; Wolfe, B.A.

    1982-01-01

    The need to objectively evaluate the progress being made by the Basalt Waste Isolation Project (BWIP) toward establishing the feasibility of siting a nuclear waste repository in basalt (NWRB) mandates a process for evaluating the technical work of the project. To assist BWIP management in the evaluation process, the Systems Department staff has developed a BWIP Technical Program Evaluation Process (TPEP). The basic process relates progress on project technical work to the SWIP Functional and System Performance Criteria as defined in National Waste Terminal Storage (MWTS) Criteria Documents. The benefits of the TPEP to BWIP and future plans for TPEP are discussed. During fiscal year (FY) 1982, TPEP wll be further formalized and further applied to the review of BWIP technical activities.

  17. Harmonization and development of resources and tools for Italian natural language processing within the PARLI project

    CERN Document Server

    Bosco, Cristina; Delmonte, Rodolfo; Moschitti, Alessandro; Simi, Maria

    2015-01-01

    The papers collected in this volume are selected as a sample of the progress in Natural Language Processing (NLP) performed within the Italian NLP community and especially attested by the PARLI project. PARLI (Portale per l’Accesso alle Risorse in Lingua Italiana) is a project partially funded by the Ministero Italiano per l’Università e la Ricerca (PRIN 2008) from 2008 to 2012 for monitoring and fostering the harmonic growth and coordination of the activities of Italian NLP. It was proposed by various teams of researchers working in Italian universities and research institutions. According to the spirit of the PARLI project, most of the resources and tools created within the project and here described are freely distributed and they did not terminate their life at the end of the project itself, hoping they could be a key factor in future development of computational linguistics.

  18. In vitro studies of calcium phosphate silicate bone cements.

    Science.gov (United States)

    Zhou, Shuxin; Ma, Jingzhi; Shen, Ya; Haapasalo, Markus; Ruse, N Dorin; Yang, Quanzu; Troczynski, Tom

    2013-02-01

    A novel calcium phosphate silicate bone cement (CPSC) was synthesized in a process, in which nanocomposite forms in situ between calcium silicate hydrate (C-S-H) gel and hydroxyapatite (HAP). The cement powder consists of tricalcium silicate (C(3)S) and calcium phosphate monobasic (CPM). During cement setting, C(3)S hydrates to produce C-S-H and calcium hydroxide (CH); CPM reacts with the CH to precipitate HAP in situ within C-S-H. This process, largely removing CH from the set cement, enhances its biocompatibility and bioactivity. The testing results of cell culture confirmed that the biocompatibility of CPSC was improved as compared to pure C(3)S. The results of XRD and SEM characterizations showed that CPSC paste induced formation of HAP layer after immersion in simulated body fluid for 7 days, suggesting that CPSC was bioactive in vitro. CPSC cement, which has good biocompatibility and low/no cytotoxicity, could be a promising candidate as biomedical cement.

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

    Science.gov (United States)

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

    2015-05-01

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

  20. Cement industry control system based on multi agent

    Institute of Scientific and Technical Information of China (English)

    王海东; 邱冠周; 黄圣生

    2004-01-01

    Cement production is characterized by its great capacity, long-time delay, multi variables, difficult measurement and muhi disturbances. According to the distributed intelligent control strategy based on the multi agent, the multi agent control system of cement production is built, which includes integrated optimal control and diagnosis control. The distributed and multiple level structure of multi agent system for the cement control is studied. The optimal agent is in the distributed state, which aims at the partial process of the cement production, and forms the optimal layer. The diagnosis agent located on the diagnosis layer is the diagnosis unit which aims at the whole process of the cement production, and the central management unit of the system. The system cooperation is realized by the communication among optimal agents and diagnosis agent. The architecture of the optimal agent and the diagnosis agent are designed. The detailed functions of the optimal agent and the diagnosis agent are analyzed.At last the realization methods of the agents are given, and the application of the multi agent control system is presented. The multi agent system has been successfully applied to the off-line control of one cement plant with capacity of 5 000 t/d. The results show that the average yield of the clinker increases 9.3% and the coal consumption decreases 7.5 kg/t.

  1. Alternative fuels in cement industry; Alternativa braenslen i cementindustrin

    Energy Technology Data Exchange (ETDEWEB)

    Nyman, K.E.; Ek, R. [Finnsementti Oy, Parainen (Finland); Maekelae, K. [Finreci Oy (Finland)

    1997-10-01

    In this project the cement industry`s possibilities to replace half of the fossil fuels with waste derived fuels are investigated. Bench-scale experiments, pilot plant tests and full scale tests have been done with used tires and plastics wastes

  2. Cultural differences and process adaptation in international R&D project management

    DEFF Research Database (Denmark)

    Li, Xing; Li, J. Z.

    2009-01-01

    In the era of globalization, Western companies have started to explore China as a source of technology. Yet, Western R&D project management processes in China are frequently facing many problems. Some of the problems can be conceptualized by analyzing a number of known cultural contrasts between ...... project success. At the same time, lessons and recommendations on the adaptability to Chinese style business and management interactions will be drawn from the case study for international companies that locate R&D projects in China.......In the era of globalization, Western companies have started to explore China as a source of technology. Yet, Western R&D project management processes in China are frequently facing many problems. Some of the problems can be conceptualized by analyzing a number of known cultural contrasts between...

  3. Evaluating Public Participation Process in Development Projects in Thailand: A Case Study of the Hin Krut Power Plant Project

    Directory of Open Access Journals (Sweden)

    Chutarat Chompunth

    2012-01-01

    Full Text Available Problem statement: Public participation has become a vital element of environmental decision-making. Although public participation has grown tremendously in Thailand due to a rising pressure from the public, this practice often fails to solve environmental problems and conflicts. There is a keen for a systematic evaluation of the public participation process to investigate whether the participation process is effective and what works or does not work in this respect. Approach: This study evaluates the effectiveness of the public participation process of the Hin Krut power plant project through an evaluation model developed from relevant literatures. Results: It was found that the public participation process of the case study was not completely effective when tested against the evaluation criteria. The affected people had no chance to present any comments at the very beginning. The public participation process started too late, after a decision had been made and conflicts among stakeholders already occurred. Conclusion: The public participation process is not yet properly established in the Thai context. There is an urgent need to find a working model and conditions of public participation which can assist in resolving environmental problems. Finally, a set of recommendations for improving public participation process are suggested.

  4. Cemented total hip arthroplasty with Boneloc bone cement.

    Science.gov (United States)

    Markel, D C; Hoard, D B; Porretta, C A

    2001-01-01

    Boneloc cement (WK-345, Biomet Inc, Warsaw, Ind) attempted to improve cement characteristics by reducing exotherm during polymerization, lowering residual monomer and solubility, raising molecular weight, and lowering airborne monomer and aromatic amines. To study the efficacy of this cement, a selected group of 20 patients were prospectively enrolled and followed up after hip arthroplasty. All components were cemented. During the enrollment period, approximately 70 other hip arthroplasties were performed. Clinical evaluation was based on the Harris hip score. Radiographic evaluation was based on assessment of position of the components, subsidence, and/or presence of radiolucencies. Patients had follow-up for an average of 42 months (11 to 58 months); 1 was lost to follow-up. Of these, 7 (35%) had failure at last follow-up. Despite its initial promise, Boneloc cement had an unacceptably high failure rate over a relatively short follow-up period and is not recommended for use. Despite the longevity and odor toxicity problems with conventional bone cement, new cement technologies must be approached with caution.

  5. Data-driven fault detection for industrial processes canonical correlation analysis and projection based methods

    CERN Document Server

    Chen, Zhiwen

    2017-01-01

    Zhiwen Chen aims to develop advanced fault detection (FD) methods for the monitoring of industrial processes. With the ever increasing demands on reliability and safety in industrial processes, fault detection has become an important issue. Although the model-based fault detection theory has been well studied in the past decades, its applications are limited to large-scale industrial processes because it is difficult to build accurate models. Furthermore, motivated by the limitations of existing data-driven FD methods, novel canonical correlation analysis (CCA) and projection-based methods are proposed from the perspectives of process input and output data, less engineering effort and wide application scope. For performance evaluation of FD methods, a new index is also developed. Contents A New Index for Performance Evaluation of FD Methods CCA-based FD Method for the Monitoring of Stationary Processes Projection-based FD Method for the Monitoring of Dynamic Processes Benchmark Study and Real-Time Implementat...

  6. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    A K Misra; Renu Mathur

    2007-06-01

    The scope of magnesium oxychloride (MOC) cement in concrete works has been evaluated. MOC cement concrete compositions of varying strengths having good placing and finishing characteristics were prepared and investigated for their compressive and flexural strengths, -values, abrasion resistance etc. The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ratio of compressive to flexural strength varies between 6 and 8. The elastic moduli of the compositions studied are found to be 23–85 GPa and the abrasion losses between 0.11 and 0.20%. While alternate heating–cooling cycles have no adverse effect on MOC concrete, it can be made durable against freezing–thawing and the excessive exposure to water and salt attack by replacing 10% magnesium chloride solution by magnesium sulphate solution of the same concentration.

  7. Including hydrological self-regulating processes in peatland models: Effects on peatmoss drought projections.

    Science.gov (United States)

    Nijp, Jelmer J; Metselaar, Klaas; Limpens, Juul; Teutschbein, Claudia; Peichl, Matthias; Nilsson, Mats B; Berendse, Frank; van der Zee, Sjoerd E A T M

    2017-02-15

    The water content of the topsoil is one of the key factors controlling biogeochemical processes, greenhouse gas emissions and biosphere - atmosphere interactions in many ecosystems, particularly in northern peatlands. In these wetland ecosystems, the water content of the photosynthetic active peatmoss layer is crucial for ecosystem functioning and carbon sequestration, and is sensitive to future shifts in rainfall and drought characteristics. Current peatland models differ in the degree in which hydrological feedbacks are included, but how this affects peatmoss drought projections is unknown. The aim of this paper was to systematically test whether the level of hydrological detail in models could bias projections of water content and drought stress for peatmoss in northern peatlands using downscaled projections for rainfall and potential evapotranspiration in the current (1991-2020) and future climate (2061-2090). We considered four model variants that either include or exclude moss (rain)water storage and peat volume change, as these are two central processes in the hydrological self-regulation of peatmoss carpets. Model performance was validated using field data of a peatland in northern Sweden. Including moss water storage as well as peat volume change resulted in a significant improvement of model performance, despite the extra parameters added. The best performance was achieved if both processes were included. Including moss water storage and peat volume change consistently reduced projected peatmoss drought frequency with >50%, relative to the model excluding both processes. Projected peatmoss drought frequency in the growing season was 17% smaller under future climate than current climate, but was unaffected by including the hydrological self-regulating processes. Our results suggest that ignoring these two fine-scale processes important in hydrological self-regulation of northern peatlands will have large consequences for projected climate change impact on

  8. Grout cement. ; Grout cement to fill ground/grout cement to fill cracks. Chunyuyo cement. ; Jiban chunyuyo cement /hibiware chunyuyo cement

    Energy Technology Data Exchange (ETDEWEB)

    Okaue, H. (Nittetsu Cement Co. Ltd., Hokkaido (Japan))

    1991-09-01

    Ground grout cement is grouted into the ground under high pressure in high water ratio (100 to 1000%) in the form of milk differing from concrete in terms of the water-cement ratio. The grouted milk is governed by characteristics of the cement the milk itself possesses, resulting in variable grouting modes, which are divided in fracture grouting, permeation grouting and boundary grouting. Their applications include cutting off of water in dams, ground reinforcement, prevention of water gushing in tunnel excavation, natural ground reinforcement, improvement of sandy soil and prevention of its collapse, and stabilization of ground for urban civil engineering works such as subway, water supply and sewerage constructions. Grout cement to fill cracks in concrete structures is so grouted into cracks that the slurry fills up contiguous cracks to a certain level and goes upward while pushing out air or water existing in the cracks. The slurry filled into the cracks solidifies and hardens while being absorbed into the concrete, and finally integrates with the concrete. The grout cement is used to rework such concrete structures as dams, tunnels, and bridge bases. 6 figs., 4 tabs.

  9. Economic evaluation of investment project in the area of sheet metal processing

    Directory of Open Access Journals (Sweden)

    P. Trebuňa

    2017-01-01

    Full Text Available The article is oriented on the process modelling in selected company. The aim of the process modelling is a possibility to prevent the formation of future risks as a consequence of a wrong decision concerning a capital project. The analysis of actual state in society with the focus on the means of processing the lamination using computer numeric control technology is also a part of article. Based on the analysis mentioned above, the selection and the definition of the capital project have already been carried out. Final section evaluates the capital project using methodology of economic indicators by means of economic indicators of effectiveness and brings a decision whether to accept or refuse given investment.

  10. Underground void filling by cemented mill tailings

    Institute of Scientific and Technical Information of China (English)

    Choudhary Bhanwar Singh; Kumar Santosh

    2013-01-01

    Underground mining always create voids. These voids can cause subsidence of surface. So it is always a demand to fill the void in such a manner that the effect of underground mining can be minimized. Void filling using mill tailings especially in metal mining is one of the best techniques. The tailings produced in milling process have traditionally been disposed in tailing ponds creating a waste disposal and environ-mental problems in terms of land degradation, air and water pollution, etc. This disposal practice is more acute in the metal milling industry where the fine grinding, required for value liberation, results in the production of very fine tailings in large percentage. This paper includes discussions on the effectiveness of different paste mixes with varying cement contents in paste backfilling operations. The results revealed that material composition and use of super plasticizer strongly influenced the strength of cemented backfill.

  11. DESIGN OF CEMENT COMPOSITES WITH INCREASED IMPERMEABILITY

    Directory of Open Access Journals (Sweden)

    Fedyuk Roman Sergeevich

    2016-05-01

    Full Text Available The paper deals with the development of composite binders for producing concrete with improved characteristics of gas, water and vapor permeability. The authors investigate the processes of composite materials formation in order of decreasing scale levels from macro to nanostructures. The criteria for optimization of the volume of dispersed additives in concrete are offered. The authors theoretically studied the technological features of the formation of hydrated cement stone structure. A positive effect of nanodispersed additives on the structure and physico-mechanical properties of cement composite materials are predicted. Thanks to its improved features, such as good ratio of strength and body density, high density and lifetime, the modified concrete may be used when solving various practical tasks of the construction branch.

  12. 21 CFR 888.4200 - Cement dispenser.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027)...

  13. Evaluating Process Quality Based on Change Request Data - An Empirical Study of the Eclipse Project

    Science.gov (United States)

    Schackmann, Holger; Schaefer, Henning; Lichter, Horst

    The information routinely collected in change request management systems contains valuable information for monitoring of the process quality. However this data is currently utilized in a very limited way. This paper presents an empirical study of the process quality in the product portfolio of the Eclipse project. It is based on a systematic approach for the evaluation of process quality characteristics using change request data. Results of the study offer insights into the development process of Eclipse. Moreover the study allows assessing applicability and limitations of the proposed approach for the evaluation of process quality.

  14. Cements containing by-product gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Bensted, J. [University of Greenwich, London (United Kingdom). School of Biological and Chemical Sciences

    1995-12-31

    Chemical by-product gypsum can readily replace natural gypsum in Portland cements and in blended cements like Portland pfa cement and Portland blast furnace cement without technical detriment in many instances. Indeed, sometimes the technical performance of the cement can be enhanced. The hydration chemistry is often changed, in that where there is at least some retardation of setting, more AFT phase (ettringite) is formed during early hydration at the expense of calcium silicate hydrates. By-product gypsum can also replace natural gypsum in speciality products like calcium aluminate cement-Portland cement mixes for producing quick setting cements and in calcium sulphoaluminate-type expansive cements. However, by-products gypsum have proved to be less successful for utilization in API Classes of oilwell cements, because of the greater difficulty in obtaining batch-to-batch consistency in properties like thickening time and slurry rheology. 11 refs., 3 figs., 5 tabs.

  15. A Study of Metal-Cement Composites with Additives

    Directory of Open Access Journals (Sweden)

    Mironov Victor

    2014-12-01

    Full Text Available The application of small-sized metal fillers (SMF provides a combination of high bulk density, increased durability and ferromagnetic properties of composite materials on the cement basis. However, the total strength of the composite can be compromised by poor adhesion of metal particles with the cement matrix. The use of versatile additives like microsilica and metakaolin is able to improve the structural integrity and mechanical properties of heavy concretes. The paper considers the results of a study using specimens of heavy concretes with SMF aiming to estimate its strength, structural features and ultrasonic parameters. It was found that the contact of SMF particles with the cement was not perfect, since the voids appeared between them and the cement matrix during the cement hydration process (exothermal reaction. Due to the border porosity, the specimens with the metal fillers have lower compressive strength, lower ultrasound velocity and increased frequency slope of attenuation. Microsilica and metakaolin additives facilitate better contact zone between the cement matrix and metal fillers.

  16. Porous and adsorption properties of hydrated cement paste

    Directory of Open Access Journals (Sweden)

    Marina Biljana S.

    2004-01-01

    Full Text Available Adsorption isotherms of benzene on hydrated cement pastes prepared by cement ground with and without the addition of grinding aids, triethanol amine (TEA and ethylene glycol (EG were investigated. The adsorption isotherms were interpreted by means of the Dubinin-Astakhov (DA and Dubinin-Radushkevich-Stoeckli (DRS equations. The microporous structure of cement gel (C-S-H in the cement pastes, and changes in the Gibbs free energy of adsorption were determined. The mechanical properties of the cement pastes were also measured. It was evident that pastes with additives had different parameters of the DRS and DA equations: the volume and dimensions of the gel pores, the distribution of the dimensions, the characteristic energy of adsorption, and the change in the Gibbs free energy of adsorption. The mechanical properties were also different. The dispersity of the additive-containing ground cements had a favorable effect on the hydration processes. When applying TEA, it was also necessary to analyze its influence on the chemical behavior of hydration in the starting period.

  17. How mobile are protons in the structure of dental glass ionomer cements?

    Science.gov (United States)

    Benetti, Ana R.; Jacobsen, Johan; Lehnhoff, Benedict; Momsen, Niels C. R.; Okhrimenko, Denis V.; Telling, Mark T. F.; Kardjilov, Nikolay; Strobl, Markus; Seydel, Tilo; Manke, Ingo; Bordallo, Heloisa N.

    2015-03-01

    The development of dental materials with improved properties and increased longevity can save costs and minimize discomfort for patients. Due to their good biocompatibility, glass ionomer cements are an interesting restorative option. However, these cements have limited mechanical strength to survive in the challenging oral environment. Therefore, a better understanding of the structure and hydration process of these cements can bring the necessary understanding to further developments. Neutrons and X-rays have been used to investigate the highly complex pore structure, as well as to assess the hydrogen mobility within these cements. Our findings suggest that the lower mechanical strength in glass ionomer cements results not only from the presence of pores, but also from the increased hydrogen mobility within the material. The relationship between microstructure, hydrogen mobility and strength brings insights into the material's durability, also demonstrating the need and opening the possibility for further research in these dental cements.

  18. The Hydration of Blended Cement at Low W/B Ratio

    Institute of Scientific and Technical Information of China (English)

    HU Shu-guang; LU Lin-nu; HE Yong-jia; LI Yue; DING Qing-jun

    2003-01-01

    The hydration process, hydration product and hydration heat of blended cement paste mixed with mineral admixture and expansive agent at low W/B ratio are studied by XRD , thermo analysis , and calorimetry instrument, and they were compared with those of pure cement paste. The results show that pure cement and blended cement at low W/B ratio have the same types of hydration products, but their respective amounts of hydration products of various blended cements at same ages and the vatiation law of the amount of same hydration products with ages are different; Tim joint effect of tumefaction of gel-ettringite due to water absorption and the expansive pressure on the pore and riff caused by the crystalloid ettringite is the impetus of the volume expansion of cement paste , and the former effect is much greater than the latter one .

  19. Doxycycline sustained release from brushite cements for the treatment of periodontal diseases.

    Science.gov (United States)

    Tamimi, Faleh; Torres, Jesús; Bettini, Ruggero; Ruggera, Francesca; Rueda, Carmen; López-Ponce, Manuel; Lopez-Cabarcos, Enrique

    2008-06-01

    Doxycycline (DOXY) is a wide spectrum antibiotic used in the treatment of dental, periodontal, and bone infections. Brushite cements are calcium phosphate biomaterials especially interesting for bone regeneration processes. In this work, we describe the preparation of a brushite cement containing DOXY and the drug release from the cement. DOXY solutions were mixed with the cement powder and after a 50% burst release in the first 12 h, a slow and controlled release was achieved over 3.5 days. The release of DOXY hyclate was controlled by both, diffusion and Ca(2+) interaction. Formation of DOXY-Ca(2+) chelates was detected in the cement structure using solid state fluorescence. The brushite cement loaded with DOXY hyclate had antibacterial activity against periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides frosthytus. This new biomaterial may be helpful for the treatment of periodontal diseases.

  20. Hybrid Polyvinyl Alcohol and Cellulose Fiber Pulp Instead of Asbestos Fibers in Cement-Based Composites

    Science.gov (United States)

    Shokrieh, M. M.; Mahmoudi, A.; Shadkam, H. R.

    2015-05-01

    The Taguchi method was used to determine the optimum content of a four-parameters cellulose fiber pulp, polyvinyl alcohol (PVA) fibers, a silica fume, and bentonite for cement-based composite sheets. Then cement composite sheets from the hybrid of PVA and the cellulose fiber pulp were manufactured, and their moduli of rapture were determined experimentally. The result obtained showed that cement composites with a hybrid of PVA and cellulose fiber pulp had a higher flexural strength than cellulose-fiber- reinforced cement ones, but this strength was rather similar to that of asbestos-fiber-reinforced cement composites. Also, using the results of flexural tests and an analytical method, the tensile and compressive moduli of the hybrid of PVA and cement sheet were calculated. The hybrid of PVA and cellulose fiber pulp is proposed as an appropriate alternative for substituting asbestos in the Hatschek process.

  1. A new resin-reinforced glass ionomer cement for use with orthodontic attachments.

    Science.gov (United States)

    Cohen, M; Silverman, E

    1997-08-01

    Resin cements are commonly used to bond orthodontic appliances. However, etching enamel and bracket bonding is an extremely technique-sensitive process. Moisture and saliva control, particularly in the gingival third of posterior teeth, is difficult and time-consuming, but is critical to success. Recently, a light-cure resin-reinforced glass ionomer cement was shown to perform with equal bonding capacity. This is accomplished in a wet field, without etching, and with the glass ionomer feature of fluoride release. Now, a self-cure resin-reinforced glass ionomer cement has been introduced. The self-cure cement will provide equal clinical success in areas where light curing is not possible or desired. This article compares traditional resin cements and glass ionomer cements for bonding orthodontic appliances.

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

    Science.gov (United States)

    Mossotti, Victor G.

    2014-01-01

    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

  3. Radioactive Waste Treatment and Disposal——Application Process for Immobilization of Spent Organic Ion Exchanger

    Institute of Scientific and Technical Information of China (English)

    LINMei-qiong; GANXue-ying; BAOLiang-jin; CHENHui

    2003-01-01

    Cementation process used ASC matrix is developed by CIAE. The primary objective of the project is to provide 200 L drum scale process parameter and make an improved formulation of waste form.Scientific researchers of Tsinghua take the responsibility for improving on formulation in final waste form and ensuring quality can meet requirement of GB 14569.1-93.

  4. Clean Development Mechanism: Laterite as Supplementary Cementing Material (SCM

    Directory of Open Access Journals (Sweden)

    Syed Zaighum Abbass

    2013-02-01

    Full Text Available Carbon dioxide (CO2 a major Green House Gas (GHG in the atmosphere, is believed to be largely responsible for global climate change through industrial emissions. The level of CO2 concentration has exponentially increased from about 280 ppm at the start of the industrial revolution to about 380 ppm to date. Although Kyoto protocol has bound industrialized nations to reduce green house gas emissions by 5.2% below 1990 levels around year 2008-2012, but violation continues. The cement industry is one of the major emitter of green house gases, particularly CO2 due to its energy intensive production process. It is estimated that approximately 1 tone of CO2 is released during the manufacturing of each tone of Portland cement. Most of CO2 emissions originate from burning fossil fuels and de-carbonization of limestone in a cement plant. During past several decades, the use of by-product materials in concrete, either as components of blended cements or as admixtures, has increased significantly. In this study, another alternate Supplementary Cementing Material (SCM, Laterite has been used with the objectives: to evaluate the performance of cement containing different percentages of laterite (5, 10, 15, 20, 25, and 30 %; to identify the optimum replacement percentage; and to investigate the effects of different concentrations of laterite on various properties of cement. For that purpose, laterite was tested: before blending (for elemental and mineralogical composition by using XRF, SEM and XRD: after blending (Elemental analysis using XRF, fineness test by using Blaine’s air permeability test and for particle size % on 45, 90 and 200 µ sieve, respectively; and after hydration (for mineralogical analysis using SEM. Furthermore, physical tests of manufactured cement, i.e., water consistency, setting time, Le-Chatlier-expansion and compressive strength were also evaluated and compared with limestone and fly-ash cement blends. The results show that with the

  5. New methodology for gas migration prediction before oil well cementing

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, G.H.V.P.; Martins, A.L.; Rocha, J.M.S. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)], E-mail: gustavo_cep@yahoo.com.br; Martinelli, A.E. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-04-15

    Many challenges have been presented in oil well drilling including preventing gas migration after cementing operations. This phenomenon is potentially dangerous since the gas can migrate to the surface causing the annular pressurization or lead to a blowout with catastrophic results that may include the loss of the well. If the hydrostatic pressure in front of the gas zone becomes lower than the pressure in this zone, the gas will invade the well. This work presents a comprehensive methodology to evaluate gas migration after cementing operations taking into account the critical static gel strength concept associated with time dependent viscosity behavior. A mechanistic model based on a force balance acting on gas bubble was proposed to predict the bubble displacement through the cement slurry while it gels and evaluate if the hydraulic isolation will be affected allowing project operation changes to ensure well construction safely. (author)

  6. A Stream Processing Engine Approach to Earth Science Data Processing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Timely processing of raw Earth science data for calibration and validation in a highly distributed and networked environment, and its storage at Distributed Active...

  7. Feasibility study of fluxless brazing cemented carbides to steel

    Science.gov (United States)

    Tillmann, W.; Sievers, N.

    2017-03-01

    One of the most important brazing processes is the joints between cemented carbides and steel for the tool industry such as in rotary drill hammers or saw blades. Even though this technique has already been used for several decades, defects in the joint can still occur and lead to quality loss. Mostly, the joining process is facilitated by induction heating and the use of a flux to enhance the wetting of the filler alloy on the surface of the steel and cemented carbide in an ambient atmosphere. However, although the use of flux enables successful joining, it also generates voids within the joint, which reduces the strength of the connection while the chemicals within the flux are toxic and polluting. In this feasibility study, a fluxless brazing process is used to examine the joint between cemented carbides and steel for the first time. For this, ultrasound is applied during induction heating to enable the wetting between the liquid filler metal and the surfaces of the cemented carbide and steel. The ultrasound generates cavitations within the liquid filler metal, which remove the oxides from the surface. Several filler metals such as a silver based alloy Ag449, pure Zn, and an AlSi-alloy were used to reduce the brazing temperature and to lower the thermal residual stresses within the joint. As a result, every filler metal successfully wetted both materials and led to a dense connection. The ultrasound has to be applied carefully to prevent a damage of the cemented carbide. In this regard, it was observed that single grains of the cemented carbide broke out and remained in the joint. This positive result of brazing cemented carbides to steel without a flux but using ultrasound, allows future studies to focus on the shear strength of these joints as well as the behavior of the thermally induced residual stresses.

  8. Prioritizing the countries for BOT nuclear power project using Analytic Hierarchy Process

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Woo; Roh, Myung Sub [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    This paper proposes factors influencing the success of BOT nuclear power projects and their weighting method using Analytic Hierarchy Process (AHP) to find the optimal country which developer intends to develop. To summarize, this analytic method enable the developer to select and focus on the country which has preferable circumstance so that it enhances the efficiency of the project promotion by minimizing the opportunity cost. Also, it enables the developer to quantify the qualitative factors so that it diversifies the project success strategy and policy for the targeted country. Although the performance of this study is insufficient due to the limitation of time, small sampling and security of materials, it still has the possibility to improve the analytic model more systematically through further study with more data. Developing Build-Own(or Operate)-Transfer (BOT) nuclear power project carrying large capital in the long term requires initially well-made multi-decision which it prevents sorts of risks from unexpected situation of targeted countries. Moreover, the nuclear power project in most case is practically implemented by Government to Government cooperation, so the key concern for such nuclear power project would be naturally focused on the country situation rather than project viability at planning stage. In this regard, it requires the evaluation of targeted countries before involving the project, comprehensive and proper decision making for complex judgment factors, and efficient integration of expert's opinions, etc. Therefore, prioritizing and evaluating the feasibility of country for identification of optimal project region is very meaningful study.

  9. Equilibrium Analysis of Lead in Hazardous Waste During Co-Processing with Cement Kiln%危险废物水泥窑共处置过程Pb的热力学平衡

    Institute of Scientific and Technical Information of China (English)

    王雷; 金宜英; 李润东; 聂永丰

    2011-01-01

    An equilibrium analysis was performed to determine the migration characteristics of lead under the conditions of sintering in cement kiln and municipal solid waste (MSW) incineration. Using the thermodynamic equilibrium software CHEMK1N, the Gibbs free energy of the reaction system was minimized according to chemical potentials combined with atom population constraints. The results indicate that both chloride and SiO2 have great effect on the thermodynamic behavior of lead. Chlorides promote the evaporation of lead, while SiO2 stabilizes lead into silicate. When the incineration temperature in incinerator is higher than 900 K, chlorides mainly exist as HC1. When the sintering temperature is lower than 1 450 K, the ratio of HC1 to chloride is lower than 50%, and the highest ratio of HC1 to total chloride occurs at about 1800 K which is about 80%. Because the main component of cement raw materials is CaCO3, which generates a large amount of CaO after decomposition, an alkaline atmosphere is generated and the generation of HC1 is inhibited. The stabilized rate of lead is 45% in the sintering process in cement kiln, which is much higher than that in the incineration process in incinerator which is only 11%.%采用热力学平衡分析的方法对比研究了水泥窑煅烧条件下重金属Pb的迁移特性,并与焚烧炉焚烧条件下Pb的迁移特性进行了对比.采用CHEMKIN计算软件根据系统吉布斯白南能最小的原理进行计算.结果表明,Cl和SiO2都对重金属Pb的热力学行为有重要影响,Cl促进Pb的挥发,而SiO2有利于Pb的固定.在焚烧炉内,在温度高于900 K的条件下氯几乎全部以HCl的形式存在.在水泥窑中,温度低于1 450 K,HCl占氯的比例低于50%,HCl在约1 800K时所占的比例最大,约为80%.南于水泥生料的主要成分为CaCO3,煅烧后分解产生大量的CaO,使水泥窑内呈现碱性气氛,抑制了HCl气体的生成.水泥窑煅烧过程Pb的固定率为45

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-30

    The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per

  11. Savannah River Site Salt Processing Project: FY2002 Research and Development Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, Harry D.; Leugemors, Robert K.; Schlahta, Stephan N.; Fink, Samuel D.; Thompson, Major C.; Walker, Darrell D.

    2001-10-31

    This Plan describes the technology development program for alpha/strontium removal and Caustic Side Solvent Extraction cesium removal in FY2002. Crystalline Silicotitanate and Small Tank Tetratphenylborate Precipitation are discussed as possible backup technologies. Previous results are summarized in the Savannah River Site Salt Processing Project Research and Development Summary Report

  12. Participation, Roles and Processes in a Collaborative Action Research Project: A Reflexive Account of the Facilitator

    Science.gov (United States)

    Avgitidou, Sofia

    2009-01-01

    This paper analyses and discusses the roles and participation of those involved in a collaborative action research project to highlight the factors that influenced their content, quality and intensity. Emphasis is given to the reflections of the facilitator (author) on the processes employed to achieve equal participation and roles in the action…

  13. Facilitating Work Based Learning Projects: A Business Process Oriented Knowledge Management Approach

    NARCIS (Netherlands)

    Miao, Yongwu; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Sloep, P. B., & Koper, R. (2009). Facilitating Work Based Learning Projects: A Business Process Oriented Knowledge Management Approach. Presented at the 'Open workshop of TENCompetence - Rethinking Learning and Employment at a Time of Economic Uncertainty-event'. November, 19, 2009, Manche

  14. Savannah River Site Salt Processing Project: FY2002 Research and Development Program Plan, Rev. 1

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, Harry D.; Leugemors, Robert K.; Schlahta, Stephan N.; Fink, Samuel D.; Thompson, Major C.; Walker, Darrell D.

    2001-12-10

    This Plan describes the technology development program for alpha/strontium removal and Caustic Side Solvent Extraction cesium removal in FY2002. Crystalline Silicotitanate and Small Tank Tetratphenylborate Precipitation are discussed as possible backup technologies. Previous results are summarized in the Savannah River Site Salt Processing Project Research and Development Summary Report.

  15. Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard 3.8 kW silicon carbide (SiC) power supply for the Power Processing Unit (PPU) of...

  16. A formal risk management process for instrumentation projects at the Anglo-Australian Observatory

    Science.gov (United States)

    Orr, David R.; Heng, Anthony

    2010-07-01

    Risk management is a dynamic activity that takes place throughout the development process from the concept phase to the retirement phase of the project. The successful management of risk is a critical part of the instrumentation development process at the AAO. The AAO has a risk management process based on the AS/ISO standard for risk management. Brainstorming sessions are conducted with the project team. Potential project risks are identified by the team and grouped into the categories of technical, political, operational, logistical, environmental, and safety. A risk matrix is populated with details of each risk. The risk is then ranked based on the consequence and likelihood according to the scale of Low, Moderate, Significant, and High. The level of risk is evaluated; mitigation control mechanisms are identified, and assigned to a specific team member for resolution. Risk management is used as a management tool for the HERMES project. The top 5 risks are identified, and management efforts are then concentrating on reducing these risks. Risk management is also used during the development process as a trade study tool to evaluate different design options and assist senior management to make informed decisions.

  17. Facilitating Work Based Learning Projects: A Business Process Oriented Knowledge Management Approach

    NARCIS (Netherlands)

    Miao, Yongwu; Sloep, Peter; Koper, Rob

    2009-01-01

    Miao, Y., Sloep, P. B., & Koper, R. (2010). Facilitating Work Based Learning Projects: A Business Process Oriented Knowledge Management Approach. In D. Griffiths & R. Koper (Eds.), Rethinking Learning and Employment at a Time of Economic Uncertainty. Proceedings of the 6th TENCompetence Open worksho

  18. The Aluminum Deep Processing Project of North United Aluminum Landed in Qijiang

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>On April 10,North United Aluminum Company respectively signed investment cooperation agreements with Qijiang Industrial Park and Qineng Electricity&Aluminum Co.,Ltd,signifying the landing of North United Aluminum’s aluminum deep processing project in Qijiang.

  19. Magnesium substitution in brushite cements.

    Science.gov (United States)

    Alkhraisat, Mohammad Hamdan; Cabrejos-Azama, Jatsue; Rodríguez, Carmen Rueda; Jerez, Luis Blanco; Cabarcos, Enrique López

    2013-01-01

    The use of magnesium-doped ceramics has been described to modify brushite cements and improve their biological behavior. However, few studies have analyzed the efficiency of this approach to induce magnesium substitution in brushite crystals. Mg-doped ceramics composed of Mg-substituted β-TCP, stanfieldite and/or farringtonite were reacted with primary monocalcium phosphate (MCP) in the presence of water. The cement setting reaction has resulted in the formation of brushite and newberyite within the cement matrix. Interestingly, the combination of SAED and EDX analyses of single crystal has indicated the occurrence of magnesium substitution within brushite crystals. Moreover, the effect of magnesium ions on the structure, and mechanical and setting properties of the new cements was characterized as well as the release of Ca(2+) and Mg(2+) ions. Further research would enhance the efficiency of the system to incorporate larger amounts of magnesium ions within brushite crystals.

  20. Radionuclide and metal sorption on cement and concrete

    CERN Document Server

    Ochs, Michael; Wang, Lian

    2016-01-01

    Cementitious materials are being widely used as solidification/stabilisation and barrier materials for a variety of chemical and radioactive wastes, primarily due to their favourable retention properties for metals, radionuclides and other contaminants. The retention properties result from various mineral phases in hydrated cement that possess a high density and diversity of reactive sites for the fixation of contaminants through a variety of sorption and incorporation reactions. This book presents a state of the art review and critical evaluation of the type and magnitude of the various sorption and incorporation processes in hydrated cement systems for twenty-five elements relevant for a broad range of radioactive and industrial wastes. Effects of cement evolution or ageing on sorption/incorporation processes are explicitly evaluated and quantified. While the immobilisation of contaminants by mixing-in during hydration is not explicitly addressed, the underlying chemical processes are similar. A quantitativ...

  1. Portland cement-blast furnace slag blends in oilwell cementing applications

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.T.; DiLullo, G.; Hibbeler, J. [and others

    1995-12-31

    Recent investigations of blast furnace slag cementing technologies. have been expanded to include Portland cement/blast furnace slag blends. Mixtures of Portland cement and blast furnace slag, while having a long history of use in the construction industry, have not been used extensively in oilwell cementing applications. Test results indicate that blending blast furnace slag with Portland cement produces a high quality well cementing material. Presented are the design guidelines and laboratory test data relative to mixtures of blast furnace slag and Portland cements. Case histories delineating the use of blast furnace slag - Portland cement blends infield applications are also included.

  2. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Deok Hyun, E-mail: dmoon10@hotmail.com [W.M. Keck Geoenvironmental Laboratory, Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Department of Environmental Engineering, Chosun University, Gwangju 501-759 (Korea, Republic of); Grubb, Dennis G. [W.M. Keck Geoenvironmental Laboratory, Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Schnabel Engineering, LLC, 510 East Gay Street, West Chester, PA 19380 (United States); Reilly, Trevor L. [W.M. Keck Geoenvironmental Laboratory, Center for Environmental Systems, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO{sub 3}{sup 2-}) and selenate (SeO{sub 4}{sup 2-}). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10 mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration <10 mg/L. Several treatments satisfied the USEPA TCLP best demonstrated available technology (BDAT) limits (5.7 mg/L) for selenium at pozzolan doses up to 10 times less than the treatments that established the BDAT. Neither pozzolan was capable of reducing the TCLP-Se(VI) concentrations below 25 mg/L. Se-soil-cement slurries aged for 30 days enabled the identification of Se precipitates by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX). XRD and SEM-EDX analyses of the Se(IV)- and Se(VI)-soil-cement slurries revealed that the key selenium bearing phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO{sub 3}.H{sub 2}O) and selenate substituted ettringite (Ca{sub 6}Al{sub 2}(SeO{sub 4}){sub 3}(OH){sub 12}.26H{sub 2}O), respectively.

  3. Structural and phase characterization of bioceramics prepared from tetracalcium phosphate-monetite cement and in vitro osteoblast response.

    Science.gov (United States)

    Stulajterova, Radoslava; Medvecky, Lubomir; Giretova, Maria; Sopcak, Tibor

    2015-05-01

    Biphasic porous calcium phosphate ceramics was prepared by sintering of transformed tetracalcium phosphate-monetite cement. After annealing hydroxyapatite, β- or α-TCP were found as main phases in ceramic substrates and a highly microporous microstructure of cement ceramics was created without an addition of porosifier. The origin microstructure features characteristic by the presence of hollow particle agglomerates in cement were preserved in microstructure of cement ceramics after annealing but the hydroxyapatite particles rose in size up to 2 µm and obtained a more regular shape. A small decrease in compressive strength was demonstrated in ceramics sintered up to 1150 °C and enhanced osteoblast proliferation was revealed on cement ceramic substrates in comparison with cement sample and conventional ceramics. The ALP activity of osteoblasts decreased with rise in sintering temperature. The prepared cement microporous ceramics could be utilized as carrier for antibiotics, drugs, growth factors, enzymes or other substances stimulating healing process.

  4. UMTRA Surface Project management action process document. Final report: Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    A critical mission of the US Department of Energy (DOE) is the planning, implementation, and completion of environmental restoration (ER) programs at facilities that were operated by or in support of the former Atomic Energy Commission (AEC) from the late 1940s into the 1970s. Among these facilities are the 24 former uranium mill sites designed in the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 (42 USC {section} 7901 et seq.) Title 1 of the UMTRCA authorized the DOE to undertake remedial actions at these designated sites and associated vicinity properties (VP), which contain uranium mill tailings and other residual radioactive materials (RRM) derived from the processing sites. Title 2 of the UMTRCA addresses uranium mill sites that were licensed at the time the UMTRCA was enacted. Cleanup of these Title 2 sites is the responsibility of the licensees. The cleanup of the Title 1 sites has been split into two separate projects: the Surface Project, which deals with the mill buildings, tailings, and contaminated soils at the sites and VPs; and the Ground Water Project, which is limited to the contaminated ground water at the sites. This management action process (MAP) document discusses the Uranium Mill Tailings Remedial Action (UMTRA) Surface Project only; a separate MAP document has been prepared for the UMTRA Ground Water Project.

  5. Calcium Orthophosphate Cements and Concretes

    Directory of Open Access Journals (Sweden)

    Sergey V. Dorozhkin

    2009-03-01

    Full Text Available In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone, calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

  6. A new approach to quantify trabecular resorption adjacent to cemented knee arthroplasty

    NARCIS (Netherlands)

    Mann, K.A.; Miller, M.A.; Pray, C.L.; Verdonschot, N.J.J.; Janssen, D.

    2012-01-01

    A new micro-computed tomography (μCT) image processing approach to estimate the loss of cement–bone interlock was developed using the concept that PMMA cement flows and cures around trabeculae during the total knee arthroplasty procedure. The initial mold shape of PMMA cement was used to estimate th

  7. Mitigating the effects of system resolution on computer simulation of Portland cement hydration

    NARCIS (Netherlands)

    Chen, W.; Brouwers, H.J.H.

    2008-01-01

    CEMHYD3D is an advanced, three-dimensional computer model for simulating the hydration processes of cement, in which the microstructure of the hydrating cement paste is represented by digitized particles in a cubic domain. However, the system resolution (which is determined by the voxel size) has a

  8. Study of the relation between hydrated portland cement composition and leaching resistance

    NARCIS (Netherlands)

    Eijk, van R.J.; Brouwers, H.J.H.

    1998-01-01

    The present paper addresses cement compositions that have an optimal resistance against acid attack and hence, low leaching rates and optimal waste containment. To this end a shrinking core leaching model is used that describes the leaching of metals from a cement sample. This process is directly re

  9. Corrosion of steel bars in cracked concrete made with ordinary portland, slag and fly ash cements

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, T.U.; Yamaji, T.; Hamada, H. [Port and Harbor Research Inst., Ministry of Land, Infrastructure and Transport (Japan); Aoyama, T. [PS Corp. (Japan)

    2001-07-01

    A study was conducted in which the marine durability of ordinary portland cement, slag and fly ash cement was examined using 15 year old plain and reinforced concrete cylindrical specimens. The performance of these cements was then examined for pre-cracked reinforced concrete prism samples. The process of manufacturing cement emits huge amounts of carbon dioxide into the global atmosphere. Replacing a portion of the cement with by-products from the steel industry and thermal power plants (which are both huge emitters of carbon dioxide) can lower carbon dioxide emissions and also solve the disposal issue of slag and fly ash while increasing the long-term durability of concrete structures. In this study, concrete cylindrical specimens were made of ordinary portland cement, slag and fly ash cements. The specimens were 100 x 100 x 600 mm prisms of different types of cement. Water-to-cement ratios were 0.45 and 0.55. Both tap water and seawater were used as mixing water. The samples were exposed in tidal pools for 15 years to evaluate the compressive strength of the concrete, corrosion of the steel bars, and chloride-ion concentrations in the concrete. It was shown that, with the exception of fly ash cements, the compressive strength of most cements increased after 15 years of exposure compared to its 28 day strength. Type C slag cement demonstrated the best performance against chloride-ion at the surface of concrete made with slag and fly ash. Voids in the steel-concrete interface make it possible for corrosion pits to develop. The use of seawater as mixing water results in earlier strength development at 28 days and does not cause to the strength of the concrete to regress after 15-years of exposure, but it causes more corrosion of steel bars at a lower cover depth. Corrosion of steel bars is not an issue at deeper cover depths. 15 refs., 19 tabs., 13 figs.

  10. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    Energy Technology Data Exchange (ETDEWEB)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  11. Mechanical Properties and Cytocompatibility Improvement of Vertebroplasty PMMA Bone Cements by Incorporating Mineralized Collagen

    Directory of Open Access Journals (Sweden)

    Hong-Jiang Jiang

    2015-05-01

    Full Text Available Polymethyl methacrylate (PMMA bone cement is a commonly used bone adhesive and filling material in percutaneous vertebroplasty and percutaneous kyphoplasty surgeries. However, PMMA bone cements have been reported to cause some severe complications, such as secondary fracture of adjacent vertebral bodies, and loosening or even dislodgement of the set PMMA bone cement, due to the over-high elastic modulus and poor osteointegration ability of the PMMA. In this study, mineralized collagen (MC with biomimetic microstructure and good osteogenic activity was added to commercially available PMMA bone cement products, in order to improve both the mechanical properties and the cytocompatibility. As the compressive strength of the modified bone cements remained well, the compressive elastic modulus could be significantly down-regulated by the MC, so as to reduce the pressure on the adjacent vertebral bodies. Meanwhile, the adhesion and proliferation of pre-osteoblasts on the modified bone cements were improved compared with cells on those unmodified, such result is beneficial for a good osteointegration formation between the bone cement and the host bone tissue in clinical applications. Moreover, the modification of the PMMA bone cements by adding MC did not significantly influence the injectability and processing times of the cement.

  12. Sustainability and Governance in Developing Open Source Projects as Processes of In-Becoming

    Directory of Open Access Journals (Sweden)

    Daniel Curto-Millet

    2013-01-01

    Full Text Available Sustainability is often thought of as a binary state: an open source project is either sustainable or not. In reality, sustainability is much more complex. What makes this project more sustainable than that one? Why should it be assumed in the first place that sustainability is a prolonged state of an ingraced project? The threads are pulled from their yarns in many directions. This article attempts to reconceptualize some assumed notions of the processes involved in developing open source software. It takes the stance in favour of studying the fluctuant nature of open source and the associated artefacts, not as well-defined objects, but as commons that are continually built upon, evolved, and modified; sometimes in unexpected ways. Further, the governance of these commons is an ongoing process, tightly linked with the way in which these commons are allowed to further develop. This perspective of "in-becoming" is useful in understanding the efforts and processes that need to be provided to sustainably govern the development of open source projects and the advantages for managing requirements derived therein.

  13. Planning and leading of the technological processes by mechanical working with microsoft project

    Science.gov (United States)

    Nae, I.; Grigore, N.

    2016-08-01

    Nowadays, fabrication systems and methods are being modified; new processing technologies come up, flow sheets develop a minimum number of phases, the flexibility of the technologies grows up, new methods and instruments of monitoring and leading the processing operations also come up. The technological course (route, entry, scheme, guiding) referring to the series of the operation, putting and execution phases of a mark in order to obtain the final product from the blank is represented by a sequence of activities realized by a logic manner, on a well determined schedule, with a determined budget and resources. Also, a project can be defined as a series of specific activities, methodical structured which they aim to finish a specific objective, within a fixed schedule and budget. Within the homogeneity between the project and the technological course, this research is presenting the defining of the technological course of mechanical chip removing process using Microsoft Project. Under these circumstances, this research highlights the advantages of this method: the celerity using of other technological alternatives in order to pick the optimal process, the job scheduling being constrained by any kinds, the standardization of some processing technological operations.

  14. Low SO2 Emission Preheaters for Cement Production

    DEFF Research Database (Denmark)

    Rasmussen, Martin Hagsted

    Themost common way of producing cement today is effected through what is known as the dry process. If the raw materials used in this process contain sulphide, the plant layout can lead to emissions of SO2 from the preheater tower. SO2 emissions are most often caused by the oxidation of pyritic...... showed that this figure could be between 90 kJ/mole and 140 kJ/mole, with a corresponding change of preexponential factors. The ability to predict emissions is very important in the design of cement plants. In this thesis the zone model concept has been applied to the modelling of the cyclone stages...

  15. Dust extraction from gas in cement kilns, using bag filters; Depoussierage des gaz de four cimentier par les filtres a manches

    Energy Technology Data Exchange (ETDEWEB)

    Harmegnies, M. [CALCIA, 78 - Guerville (France). Direction Technique

    1996-12-31

    After a review of regulations concerning cement plant emissions, the two main cement production techniques (dry and semi-dry processes) are described and the electrostatic and bag filter de-dusting techniques are compared. Examples of pilot applications of these techniques in two French cement plants are presented and operating results (performances, transient procedures, costs) are discussed

  16. Advanced Coal Conversion Process Demonstration Project. Final technical progress report, January 1, 1995--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    This report describes the technical progress made on the Advanced Coal Conversion Process (ACCP) Demonstration Project from January 1, 1995 through December 31, 1995. This project demonstrates an advanced, thermal, coal upgrading process, coupled with physical cleaning techniques, that is designed to upgrade high-moisture, low-rank coals to a high-quality, low-sulfur fuel, registered as the SynCoal Process. The coal is processed through three stages (two heating stages followed by an inert cooling stage) of vibrating fluidized bed reactors that remove chemically bound water, carboxyl groups, and volatile sulfur compounds. After thermal upgrading, the coal is put through a deep-bed stratifier cleaning process to separate the pyrite-rich ash from the coal. The SynCoal Process enhances low-rank, western coals, usually with a moisture content of 25 to 55 percent, sulfur content of 0.5 to 1.5 percent, and heating value of 5,5000 to 9,000 British thermal units per pound (Btu/lb), by producing a stable, upgraded, coal product with a moisture content as low as 1 percent, sulfur content as low as 0.3 percent, and heating value up to 12,000 Btu/lb. During this reporting period, the primary focus for the ACCP Demonstration Project team was to expand SynCoal market awareness and acceptability for both the products and the technology. The ACCP Project team continued to focus on improving the operation, developing commercial markets, and improving the SynCoal products as well as the product`s acceptance.

  17. Multimode Process Monitoring Based on Fuzzy C-means in Locality Preserving Projection Subspace

    Institute of Scientific and Technical Information of China (English)

    解翔; 侍洪波

    2012-01-01

    For complex industrial processes with multiple operational conditions, it is important to develop effective monitoring algorithms to ensure the safety of production processes. This paper proposes a novel monitoring strategy based on fuzzy C-means. The high dimensional historical data are transferred to a low dimensional subspace spanned by locality preserving projection. Then the scores in the novel subspace are classified into several overlapped clusters, each representing an operational mode. The distance statistics of each cluster are integrated though the membership values into a novel BID (Bayesian inference distance) monitoring index. The efficiency and effectiveness of the proposed method are validated though the Tennessee Eastman benchmark process.

  18. MEASUREMENT PROCESS OF SOFTWARE DEVELOPMENT PROJECTS FOR SUPPORTING STRATEGIC BUSINESS OBJECTIVES IN SOFTWARE DEVELOPING COMPANIES

    Directory of Open Access Journals (Sweden)

    Sandra Lais Pedroso

    2013-08-01

    Full Text Available Software developing companies work in a competitive market and are often challenged to make business decisions with impact on competitiveness. Models accessing maturity for software development processes quality, such as CMMI and MPS-BR, comprise process measurements systems (PMS. However, these models are not necessarily suitable to support business decisions, neither to achieve strategic goals. The objective of this work is to analyze how the PMS of software development projects could support business strategies for software developing companies. Results taken from this work show that PMS results from maturity models for software processes can be suited to help evaluating operating capabilities and supporting strategic business decisions.

  19. Factors influencing calcium phosphate cement shelf-life.

    Science.gov (United States)

    Gbureck, Uwe; Dembski, Sofia; Thull, Roger; Barralet, Jake E

    2005-06-01

    Long-term stability during storage (shelf-life) is one major criterion for the use of a material as medical device. This study aimed to investigate the ageing process of beta-tricalcium phosphate/monocalcium phosphate cement powders when stored in sealed containers at ambient conditions. This kind of cement type is of interest because it is forming dicalcium phosphate dihydrate (brushite) when set, which is in contrast to hydroxyapatite resorbable in physiological conditions. The stability of cements was checked by either measuring the phase composition of powders as well as the setting time and compressive strength when mixed with sodium citrate as liquid. Critical factors influencing ageing were found to be temperature, humidity and the mixing regime of the powders. Mechanically mixed cement powders which were stored in normal laboratory atmosphere (22 degrees C, 60% rel. humidity) converted to dicalcium phosphate anhydrous (monetite) within a few days; this could be mechanistically related to a dissolution/precipitation process since humidity condensed on the particles' surfaces and acted as reaction medium. Various storage conditions were found to be effective in prolonging cement stability which were in order of effectiveness: adding solid citric acid retardant>dry argon atmosphere=gentle mixing (minimal mechanical energy input) low temperature.

  20. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  1. NOx from cement production - reduction by primary measures

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup

    1999-01-01

    cement production processes cement is typically produced by thermally treating a mixture of limestone and clay minerals in kiln systems consisting of a rotary kiln and a calciner. Clinker burning at a temperature of about 1450 °C takes place in the internally fired rotary kiln and calcination, which...... is the most energy demanding process, takes place at lower temperature in the calciner. When dealing with NOx from solid fuel combustion it is important to consider reactions of volatile contents and char separately.Chapter 4 presents an overview of NOx from cement production. Thermal NOx dominates from......, calciner operation, fuel properties and on the NOx level from the rotary kiln. The low-NOx calciner types presently marketed are based on combinations of reburning, air staging and temperature control and seem equivalent in their ability to restrict NOx formation. If fuels with a significant volatile...

  2. Letter of Intent for RPP Characterization Program Process Engineering and Hanford Analytical Services and Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    ADAMS, M.R.

    2000-02-25

    The Characterization Project level of success achieved by the River Protection Project (RPP) is determined by the effectiveness of several organizations across RPP working together. The requirements, expectations, interrelationships, and performance criteria for each of these organizations were examined in order to understand the performances necessary to achieve characterization objectives. This Letter of Intent documents the results of the above examination. It formalizes the details of interfaces, working agreements, and requirements for obtaining and transferring tank waste samples from the Tank Farm System (RPP Process Engineering, Characterization Project Operations, and RPP Quality Assurance) to the characterization laboratory complex (222-S Laboratory, Waste Sampling and Characterization Facility, and the Hanford Analytical Service Program) and for the laboratory complex analysis and reporting of analytical results.

  3. Cementation of Loose Sand Particles based on Bio-cement

    Institute of Scientific and Technical Information of China (English)

    RONG Hui; QIAN Chunxiang

    2014-01-01

    Loose sand particles could be cemented to sandstone by bio-cement (microbial induced magnesium carbonate). The bio-sandstone was firstly prepared, and then the compressive strength and the porosity of the sandstone cemented by microbial induced magnesium carbonate were tested to characterize the cementation effectiveness. In addition, the formed mineral composition and the microstructure of bio-sandstone were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The experimental results show that the feasibility of binding loose sand particles using microbial induced magnesium carbonate precipitation is available and the acquired compressive strength of bio-sandstone can be excellent at certain ages. Moreover, the compressive strength and the porosity could be improved with the increase of microbial induced magnesium carbonate content. XRD results indicate that the morphology of magnesium carbonate induced by microbe appears as needles and SEM results show that the cementation of loose sand particles to sandstone mainly relies on the microbial induced formation of magnesium carbonate precipitation around individual particles and at particle-particle contacts.

  4. Advanced Coal Conversion Process Demonstration Project. Technical progress report, January 1, 1993--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    This report describes the technical progress made on the Advanced Coal Conversion Process (ACCP) Demonstration Project from January 1, 1993, through December 31, 1993. This project demonstrates an advanced, thermal, coal drying process, coupled with physical cleaning techniques, that is designed to upgrade high-moisture, low- rank coals to a high-quality, low-sulfur fuel, registered as the SynCoal{reg_sign} process. The coal is processed through three stages (two heating stages followed by an inert cooling stage) of vibrating fluidized bed reactors that remove chemically bound water, carboxyl groups, and volatile sulfur compounds. After thermal processing, the coal is put through a deep-bed stratifier cleaning process to separate the pyrite-rich ash from the coal. Rosebud SynCoal Partnership`s ACCP Demonstration Facility entered Phase III, Demonstration Operation, in April 1992 and operated in an extended startup mode through August 10, 1993, when the facility became commercial. Rosebud SynCoal Partnership instituted an aggressive program to overcome startup obstacles and now focuses on supplying product coal to customers. Significant accomplishments in the history of the SynCoal{reg_sign} process development are shown in Appendix A.

  5. Embodied Energy and CO2 Analyses of Mud-brick and Cement-block Houses

    Directory of Open Access Journals (Sweden)

    Abanda F.Henry

    2014-01-01

    Full Text Available In building projects, the extraction of vast quantities of materials is too common. The extraction of materials and the erection of buildings consume embodied energy and emit carbon dioxide (CO2 that impact negatively on the environment. Therefore it is necessary to consider embodied energy and CO2 amongst other factors in selecting building materials for use in building projects. In most developing countries, building environmental performance analysis has yet to gain interest from the construction community. However, with recent increase in sustainability awareness, both developed and developing nations have engaged in efforts to tackle this challenge. Embodied energy and CO2 are among the leading parameters in assessing environmental building performance. In Cameroon, studies about the assessment of embodied energy and CO2 of building projects are scarce. Hence, professionals find it difficult to make alternative choices for building materials to use in their different building projects. This study uses a detailed process analysis approach supported by two popular housing types in Cameroon (mud-brick and cement-block houses to assess the embodied energy and CO2 impacts from building materials. The emerging Building Information Modelling (BIM tool was used to validate the computational results of the process analysis method. The findings revealed the embodied energy and CO2 for the mud-brick houses are 137934.91 MJ (2007.8 MJ/m2 and 15665.56 Kg CO2 (228.03 Kg CO2/m2; the cement-block houses are 292326.81 MJ (3065.51 MJ/m2 and 37829.19 Kg CO2 (396.7 Kg CO2/m2 respectively. Thus, the cement-block house expends at least 1.5 times more embodied energy and emits at least 1.7 times more embodied CO2 than mud-brick house. Although these findings cannot be generalized, they nonetheless indicate the importance of considering embodied energy and CO2 in making alternative choices for use in different building projects.

  6. California Food Processing Industry Wastewater Demonstration Project: Phase I Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Glen; Atkinson, Barbara; Rhyne, Ivin

    2009-09-09

    Wastewater treatment is an energy-intensive process and electricity demand is especially high during the utilities summer peak electricity demand periods. This makes wastewater treatment facilities prime candidates for demand response programs. However, wastewater treatment is often peripheral to food processing operations and its demand response opportunities have often been overlooked. Phase I of this wastewater demonstration project monitored wastewater energy and environmental data at Bell-Carter Foods, Inc., California's largest olive processing plant. For this monitoring activity the project team used Green Energy Management System (GEMS) automated enterprise energy management (EEM) technologies. This report presents results from data collected by GEMS from September 15, 2008 through November 30, 2008, during the olive harvest season. This project established and tested a methodology for (1) gathering baseline energy and environmental data at an industrial food-processing plant and (2) using the data to analyze energy efficiency, demand response, daily peak load management, and environmental management opportunities at the plant. The Phase I goals were to demonstrate the measurement and interrelationship of electricity demand, electricity usage, and water quality metrics and to estimate the associated CO{sub 2} emissions.

  7. Implementation of quality improvement techniques for management and technical processes in the ACRV project

    Science.gov (United States)

    Raiman, Laura B.

    1992-01-01

    Total Quality Management (TQM) is a cooperative form of doing business that relies on the talents of everyone in an organization to continually improve quality and productivity, using teams and an assortment of statistical and measurement tools. The objective of the activities described in this paper was to implement effective improvement tools and techniques in order to build work processes which support good management and technical decisions and actions which are crucial to the success of the ACRV project. The objectives were met by applications in both the technical and management areas. The management applications involved initiating focused continuous improvement projects with widespread team membership. The technical applications involved applying proven statistical tools and techniques to the technical issues associated with the ACRV Project. Specific activities related to the objective included working with a support contractor team to improve support processes, examining processes involved in international activities, a series of tutorials presented to the New Initiatives Office and support contractors, a briefing to NIO managers, and work with the NIO Q+ Team. On the technical side, work included analyzing data from the large-scale W.A.T.E.R. test, landing mode trade analyses, and targeting probability calculations. The results of these efforts will help to develop a disciplined, ongoing process for producing fundamental decisions and actions that shape and guide the ACRV organization .

  8. Hydraulic Conductivity of Residual Soil-Cement Mix

    Science.gov (United States)

    Govindasamy, P.; Taha, M. R.

    2016-07-01

    In Malaysia, although there are several researches on engineering properties of residual soils, however study on the hydraulic conductivity properties of metasedimentary residual soils is still lacking. Construction of containment walls like slurry wall techniques can be achieved with hydraulic conductivity of approximately 5 x 10-7cm/sec. The objectives of the study were to determine the physical properties of metasedimentary residual soils and to determine the influence of 1%, 3%, 5% and 10% of cement on hydraulic conductivity parameters. The coefficient of hydraulic conductivity of the soil naturally and soil-cement mixtures were determined by using the falling head test. According to the test, the hydraulic conductivity of the original soil was 4.16 x 10-8 m/s. The value decreases to 3.89 x 10-8 m/s, 2.78 x 10-8 m/s then 6.83 x 10-9 m/s with the addition of 1%, 3% and 5% of cement additives, respectively. During the hydration process, cement hydrates is formed followed by the increase in pH value and Ca(OH)2 which will alter the modification of pores size and distribution. When the quantity of cement increases, the pores size decrease. But, the addition of 10% cement gives an increased hydraulic conductivity value to 2.78 x 10-8 m/s. With 10%, the pore size increase might due to flocculation and agglomeration reaction. The generated hydraulic conductivity values will indirectly become a guide in the preliminary soil cement stabilization to modify the properties of the soil to become more like the properties of a soft rock.1. Introduction

  9. Factor ten emission reductions : the key to sustainable development and economic prosperity for the cement and concrete industry

    Energy Technology Data Exchange (ETDEWEB)

    Horton, R. [Alchemix Corp., Pittsburgh, PA (United States)

    2001-07-01

    This paper proposes that the negative environmental effects of current cement/concrete production can be reduced by a factor of 10 by using cement blends with minimum portland cement and maximum pozzolanic loading. In addition to extending the longevity of concrete, such cement blends also avoid the huge cost of repairs and replacement cycles. Market forces will drive this transition toward sustainable development in the concrete and cement industry. The economic advantages of improving the quality of the concrete are great. Even if improving the concrete doubles the price of the highest quality cement, this would only add 2 per cent to the cost of the overall construction project, but the service life of the structure would give a many-fold return on this added investment. Also, regulations on carbon dioxide emissions in the near future will assume economic importance in the manufacturing of cement and concrete. While portland cements have dominated the construction industry for more than 150 years, new blended cements priced on a performance basis will become the standard in the twenty first century. Currently, the typical cement formulation in the United States, if it contains fly ash, contains 15 to 20 per cent fly ash by weight of the total cementitious material. This paper states that soon the number will be 50 to 60 per cent ash. Fly ash will be widely acknowledged for improving critical performance characteristics of concrete such as workability, impermeability and durability. Carbon dioxide credits will also be a major economic factor that will drive the cement industry toward a factor ten environmental improvement. The Kyoto Protocol calls for the trading of greenhouse gas credits which includes carbon dioxide credits. Under the new system, cement producers will be taxed on excess emissions, while those using pozzolans in their cements will earn credits to offset these penalties. 10 refs.

  10. Successful field implementation of novel cementing solution for ISC wells : case histories

    Energy Technology Data Exchange (ETDEWEB)

    Meher, R.K.; Suyan, K.M.; Dasgupta, D. [Society of Petroleum Engineers, Dubai (United Arab Emirates)]|[Oil and Natural Gas Corp. Ltd., Tel Bhavan, Dehradun (India); Deodhar, S.; Sharma, V.; Jain, V.K. [Oil and Natural Gas Corp. Ltd., Tel Bhavan, Dehradun (India)

    2008-10-15

    Cementation of in-situ combustion (ISC) wells is challenging since wells are frequently associated with weak and unconsolidated formation. However, cement rise up to surface is desired to prevent casing failure. Moreover, the cement sheath is also required to withstand extreme stresses due to high temperature cycling experienced during in-situ combustion process. In response to the problem of inadequate placement time and flash setting, Portland cement-silica blends were used for cementation of ISC wells in India instead of alumina cement blends. However, the use of the cement-silica blends has resulted in insufficient cement rise because of losses during cementation. The cured cement failed to contain the strength and permeability in course of ISC process causing charge of sub-surface shallower layers. This paper discussed the development and implementation of a non-alumina based thermally stable lightweight lead slurry and a ductile high temperature resistance tail slurry for mitigating these problems. The paper provided details of the study as well as four successful case histories. The cementing practice for ISC wells around the world was first described and illustrated. Next, the paper outlined the formulation of thermally stable tail slurry through laboratory studies. Slurry parameters of the tail slurry were presented, including slurry weight; thickening time; fluid loss; free fluid; and rheology. The paper also reviewed a study of compressive strength and permeability of thermal slurry; slurry parameters of the lightweight lead slurry; and study of compressive strength and permeability of lightweight thermal slurry. 8 refs., 4 tabs., 12 figs.

  11. Determination of risk identification process employed by NHS for a PFI hospital project in the UK

    Directory of Open Access Journals (Sweden)

    F. E. Mohamed Ghazali

    2009-12-01

    Full Text Available Long-term concession contracts associated with Private Finance Initiative (PFI projects, such as National Health Service (NHS hospitals, are subject to substantial risks, which may not only emerge from project activities such as design and construction, but also from global issues beyond the control of project parties, such as commercial, legal and political risks. Therefore, the principal parties involved must manage risks effectively and efficiently, as early as the project initiation stage, in order to ensure a successful delivery. The aim of this paper is to examine the risk identification process of the NHS PFI hospital in the UK, as a case study, in order to determine the techniques used in risk identification, and their significance, based on estimated probabilities of occurrence. These objectives were achieved through interviews with key personnel within the NHS Trust involved. Results found the sole technique used in risk identification to be brainstorming, through which more than thirty risks were identified and classified under six risk categories: planning, pre-commissioning, design, land purchasing, construction and operation. Thirteen risks were identified as significant based on their estimated probability of occurrence had the project been developed via public procurement. The results of this research will enable public sector clients like the NHS Trust to not only identify the significant risks, which will allow them to focus more attention on developing appropriate mitigation strategies and contingency plans, but also to improve its risk identification process through the use of other techniques in order to support findings from the brainstorming process.

  12. Effects of Static Magnetic Fields on the Physical, Mechanical, and Microstructural Properties of Cement Pastes

    Directory of Open Access Journals (Sweden)

    Juan J. Soto-Bernal

    2015-01-01

    Full Text Available This paper presents the results of an experimental study carried out to comprehend the physical, mechanical, and microstructural behavior of cement pastes subjected to static magnetic fields while hydrating and setting. The experimental methodology consisted in exposing fresh cement pastes to static magnetic fields at three different magnetic induction strengths: 19.07, 22.22, and 25.37 Gauss. The microstructural characterization makes evident that there are differences in relation to amount and morphology of CSH gel; the amount of CSH is larger and its morphology becomes denser and less porous with higher magnetostatic induction strengths; it also shows the evidence of changes in the mineralogical composition of the hydrated cement pastes. The temperature increasing has no negative effects over the cement paste compressive strength since the magnetostatic field affects the process of hydration through a molecular restructuring process, which makes cement pastes improve microstructurally, with a reduced porosity and a higher mechanical strength.

  13. Studies of some phenomena in control engineering projects - With application to precipitation processes

    Energy Technology Data Exchange (ETDEWEB)

    Stoele-Hansen, Kjell

    1998-12-31

    This thesis deals with the life-cycle of a control engineering project and some phenomena encountered in such projects. Different types of control strategies are discussed and an attempt is made to classify them into categories. Some case projects are presented and forms the basis for discussing the individual`s role in a change project. Further conditions for successful implementation of new control strategies are discussed in general, but also conditions for successful implementation of new control strategies at a process section of a nickel work. Procedures for implementing new control strategies are treated and some remarks are made about operation of control strategies. An introduction is given to the modelling of precipitation in pH systems and different model formulations are discused. The modelling of pH controlled precipitations is discussed in general. A variety of dynamic models, ranging from complex to simple, are proposed and discussed. A rigorous dynamic nonlinear mechanistic model of a precipitation reactor is developed. It is based on the theory of reaction invariants and variants. The model is verified against real process data. The dynamics and characteristics of the precipitation reactor are analysed and some remarks are made with respect to controllability. A new strategy for pH control is proposed. A new model based strategy for controlling the precipitation reactions is also proposed. 93 refs., 63 figs., 10 tabs.

  14. Development of an Improved Process for Installation Projects of High Technology Manufacturing Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Sarah V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-30

    High technology manufacturing equipment is utilized at Los Alamos National Laboratory (LANL) to support nuclear missions. This is undertaken from concept initiation where equipment is designed and then taken through several review phases, working closely with system engineers (SEs) responsible for each of the affected systems or involved disciplines (from gasses to HVAC to structural, etc.). After the design is finalized it moves to procurement and custom fabrication of the equipment and equipment installation, including all of the paperwork involved. Not only are the engineering and manufacturing aspects important, but also the scheduling, financial forecasting, and planning portions that take place initially and are sometimes modified as the project progresses should requirements, changes or additions become necessary. The process required to complete a project of this type, including equipment installation, is unique and involves numerous steps to complete. These processes can be improved and recent work on the Direct Current Arc (DC Arc) Glovebox Design, Fabrication and Installation Project provides an opportunity to identify some important lessons learned (LL) that can be implemented in the future for continued project improvement and success.

  15. Flash calcination of kaolinite rich clay and impact of process conditions on the quality of the calcines: A way to reduce CO2 footprint from cement industry

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2016-01-01

    deplete metakaolin into unwanted products (e.g., mullite), which limits the use of the calcines as a supplementary cementitious material. With this regard, a dynamic model of flash calcination of kaolinite rich clay particles is developed using gPROMS (general PROcess Modeling System) to predict...... suspension calciner. The model is validated by the experimental data (e.g., the degree of dehydroxylation and the density of the calcines). Based on the model, the impacts of process conditions and feed properties on the quality of the calcination products are thoroughly examined....

  16. Discrete Return Lidar in Natural Resources: Recommendations for Project Planning, Data Processing, and Deliverables

    Directory of Open Access Journals (Sweden)

    Alistair M. S. Smith

    2009-10-01

    Full Text Available Recent years have seen the progression of light detection and ranging (lidar from the realm of research to operational use in natural resource management. Numerous government agencies, private industries, and public/private stakeholder consortiums are planning or have recently acquired large-scale acquisitions, and a national U.S. lidar acquisition is likely before 2020. Before it is feasible for land managers to integrate lidar into decision making, resource assessment, or monitoring across the gambit of natural resource applications, consistent standards in project planning, data processing, and user-driven products are required. This paper introduces principal lidar acquisition parameters, and makes recommendations for project planning, processing, and product standards to better serve natural resource managers across multiple disciplines.

  17. [Analysis of projects funded by NSFC in field of processing Chinese materia medica in recent five years].

    Science.gov (United States)

    Chen, Lei; Xia, Xing; He, Bo-sai; Hah, Li-wei

    2015-05-01

    The general situation of the approved and concluded projects of National Natural Science Foundation of China in the field of processing Chinese Materia Medica in recent five years has been reviewed. The progresses and achievements of some projects have been summarized in accordance with research area such as the processing principle, the processing technology, quality evaluation, toxicity and safety evaluation, etc. The researchers and project support units of the funded projects have been analyzed, and the problems of the applications have been also summarized.

  18. Successful Completion of Outward Transport Disposal Stage Ⅰ of Radioactive Cement Solidification

    Institute of Scientific and Technical Information of China (English)

    DU; Hong-ming; LIU; Fu-guo; JIN; Song

    2013-01-01

    As the last batch of solidification barrels arriving at the repository on May 5th,2013,the outward transport disposal stage I of radioactive cement solidification completed successfully.This project started in May,2011,lasted for 19 months,during which 9 batches,3 300 barrels of cement solidification,had been retrieved and transferred.It is a lot of preparation work and continuous improvement that to ensure the safety of the outbound work.

  19. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  20. 76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

    Science.gov (United States)

    2011-12-08

    ... Portland Cement and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the... antidumping duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... the Commission are contained in USITC Publication 4281 (December 2011), entitled Gray Portland...

  1. CO2 REDUCTION OPTIONS IN CEMENT INDUSTRY - THE NOVI POPOVAC CASE

    Directory of Open Access Journals (Sweden)

    Gordana M Stefanović

    2010-01-01

    Full Text Available The cement industry contributes about 5% to global anthropogenic CO2 emissions, and is thus an important sector in CO2-emission mitigation strategies. Carbon dioxide is emitted from the calcination process of limestone, from combustion of fuels in the kiln, and from the coal combustion during power generation. Strategies to reduce these CO2 emissions include energy efficiency improvement, new processes, shift to low carbon fuels or waste fuels in cement production, increased use of additives in cement production, alternative cements, and CO2 removal from flue gases in clinker kilns. Increased use of fly ash as an additive to cement and concrete has a number of advantages, the primary being reduction of costs of fly ash disposal, resource conservation, and cost reduction of the product. Since the production of cement requires a large amount of energy (about 2.9-3.2 GJt-1, the substitution of cement by fly ash saves not only energy but also reduces the associated greenhouse gas emissions. The paper evaluates the reduction of CO2 emissions that can be achieved by these mitigation strategies, as well as by partial substitution of cement by fly ash. The latter is important because the quality of the produced concrete depends on the physical-chemical properties of the fly ash and thus partial substitution as well as the type of fly ash (e.g., the content of CaO has an effect not only on energy consumption and emissions, but also on the produced concrete quality.

  2. Antibacterial potential of contemporary dental luting cements.

    Science.gov (United States)

    Daugela, Povilas; Oziunas, Rimantas; Zekonis, Gediminas

    2008-01-01

    The aims of this investigation were to evaluate the antibacterial activities of different types of dental luting cements and to compare antibacterial action during and after setting. Agar diffusion testing was used to evaluate the antibacterial properties of seven types of dental luting cements (glass ionomer cements (GICs), resin modified GICs, resin composite, zinc oxide eugenol, zinc oxide non-eugenol, zinc phosphate, zinc polycarboxylate cements) on Streptococcus mutans bacteria. Instantly mixed zinc phosphate cements showed the strongest antibacterial activity in contrast to the non-eugenol, eugenol and resin cements that did not show any antibacterial effects. Non-hardened glass ionomer, resin modified and zinc polycarboxylate cements exhibited moderate antibacterial action. Hardened cements showed weaker antibacterial activities, than those ones applied right after mixing.

  3. Freezing resistance of high iron phoasphoaluminate cement

    Science.gov (United States)

    Zhang, S. X.; Lu, L. C.; Wang, S. D.; Zhao, P. Q.; Gong, C. C.

    2017-03-01

    The influence of freeze-thaw cycle on the mechanical properties of high iron phoasphoaluminate cement was investigated in the present study. The visual examination was conducted to evaluate the surface damage. The deterioration considering the weight loss, modulus loss of relative dynamic elastic and strength loss of mortar were also investigated. The morphology of hydration products were analysed by SEM. Compared with ordinary Portland cement and sulphoaluminate cement, the frost resistance of high iron phosphoraluminate cement is better. Hydration products of high iron phoasphoaluminate cement contain sheet crystals, and a lot of gel form a dense three-dimensional network structure, which results in a lower porosity. Different from ordinary Portland cement, the hydration product of high iron phoasphoaluminate cement does not contain Ca(OH)2, and low alkalinity reduces its osmotic pressure. The lower porosity and osmotic pressure are the two main reasons which causes in the higher frost resistance of high iron phoasphoaluminate cement.

  4. Dual-setting brushite-silica gel cements.

    Science.gov (United States)

    Geffers, Martha; Barralet, Jake E; Groll, Jürgen; Gbureck, Uwe

    2015-01-01

    The current study describes a dual-mechanism-setting cement that combines a brushite-forming cement paste with a second inorganic silica-based precursor. Materials were obtained by pre-hydrolyzing tetraethyl orthosilicate (TEOS) under acidic conditions following the addition of a calcium phosphate cement (CPC) powder mixed of β-tricalcium phosphate and monocalcium phosphate. Cement setting occurred by a dissolution-precipitation process, while changes in pH during setting simultaneously initiated the condensation reaction of the hydrolyzed TEOS. This resulted in an interpenetrating phase composite material in which the macropores of the CPC were infiltrated by the microporous silica gel, leading to a higher density and a compressive strength ∼5-10 times higher than the CPC reference. This also altered the release of vancomycin as a model drug, whereby in contrast to the quantitative release from the CPC reference, 25% of the immobilized drug remained in the composite matrix. By varying the TEOS content in the composite, the cement phase composition could be controlled to form either brushite, anhydrous monetite or a biphasic mixture of both. The composites with the highest silicate content showed a cell proliferation similar to a hydroxyapatite reference with a significantly higher activity per cell. Surprisingly, the biological response did not seem to be attributed to the released silicate ions, but to the release of phosphate and the adsorption of magnesium ions from the cell culture medium.

  5. Utilization of Palm Oil Clinker as Cement Replacement Material

    Directory of Open Access Journals (Sweden)

    Jegathish Kanadasan

    2015-12-01

    Full Text Available The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  6. Managing the maintenance inventory of a cement manufacturer

    Directory of Open Access Journals (Sweden)

    Morne Eloff

    2013-05-01

    Full Text Available Inventory management is a crucial aspect of managing a company successfully. This is even more apparent in the case of maintenance inventories for production equipment, which impact directly on production equipment efficiency. This is a typical inventory management issue for a cement manufacturer that faces the problem of managing its maintenance inventories optimally when certain maintenance items have exceptionally long lead times (100 weeks and values in excess of R500 000. An assessment of the cement manufacturer’s approach to managing its maintenance inventories indicated various shortcomings, which have resulted in a significant level of obsolescence. One approach to managing maintenance inventories efficiently is to implement a classification of the inventory items in terms of their criticality to the cement production process. The critical nature of a component could be established through a risk-based approach (minimisation of the risk of production loss and taking into account the type of maintenance (planned vs unplanned that the component is required for. A risk-based approach should form the basis of the maintenance inventory management of the cement manufacturer as this would allow the cement manufacturer to utilise other inventory management methods effectively. In addition, it is important to ensure that employees are well versed in the different inventory management approaches utilised and that high levels of integration between departments are pursued.

  7. Chemistry of glass-ionomer cements: a review.

    Science.gov (United States)

    Nicholson, J W

    1998-03-01

    Studies of the setting of glass-ionomer cements have been carried out for over twenty years, and there is now a considerable body of information concerning the steps that lead to the conversion of a freshly mixed cement paste into a solid, durable dental restorative. This paper reviews these studies, paying particular attention to more recent work. The conclusion is that glass-ionomers consist of interpenetrating networks of inorganic and organic components forming a matrix in which particles of unreacted glass are embedded. However, there remain uncertainties over aspects of the setting chemistry, for example over the role of (+)-tartaric acid in the setting reaction, and over the nature of the fluoride species which form during the reaction. The chemistry of resin-modified glass-ionomers is also discussed and shown to be more complex than that of the simple cements. The presence of the resin component slows down the ionic cure reaction of the conventional cement, and leads to both a significant exotherm and a set material capable of absorbing water reversibly. The paper concludes that the microstructure of the set cement depends completely on chemical composition and the kinetics of the setting process, and that an understanding of the setting chemistry of these materials is thus important for optimal clinical use.

  8. Water-resisting ability of cemented broken rocks

    Institute of Scientific and Technical Information of China (English)

    Yu Bangyong; Chen Zhanqing; Yu Linli

    2016-01-01

    Using the self-designed testing system, the seepage tests for cemented broken rocks were conducted, and the impact of different factors on water-resisting ability was analyzed. The results show that (1) seepage process of the cemented broken rocks can be divided into two categories:in one category, seepage insta-bility occurs after a period of time, in the other, the permeability decreases slowly and tends to be stable, and seepage instability does not occur;(2) cementing performance of cementing agent and grain size dis-tribution are the decisive factors for water-resisting ability, with the increase of cementing performance and the mass percentage of large grains, the water-resisting ability of the specimen strengthens; (3) aggregate type has little effect on seepage stability, for the specimens with different aggregate types, the permeability and the duration of seepage instability have small difference; (4) initial porosity has a certain effect on the water-resisting ability of the specimen, but has no decisive role. With the increase of the initial porosity, the duration of seepage instability decreases.

  9. 76 FR 24519 - Gray Portland Cement and Cement Clinker From Japan; Institution of a Five-Year Review Concerning...

    Science.gov (United States)

    2011-05-02

    ... COMMISSION Gray Portland Cement and Cement Clinker From Japan; Institution of a Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United States... determine whether revocation of the antidumping duty order on gray portland cement and cement clinker...

  10. 76 FR 50252 - Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review...

    Science.gov (United States)

    2011-08-12

    ... COMMISSION Gray Portland Cement and Cement Clinker From Japan; Scheduling of an Expedited Five-Year Review Concerning the Antidumping Duty Order on Gray Portland Cement and Cement Clinker From Japan AGENCY: United... cement and cement clinker from Japan would be likely to lead to continuation or recurrence of...

  11. 电改袋技术在回转窑窑头烟气净化中的应用%Application of ESP Retroft to FF Technology in Rotary Kiln Back’s Flue Gas Cleaning System of New Dry Cement Process

    Institute of Scientific and Technical Information of China (English)

    章潮鸿

    2012-01-01

      在对水泥生产线篦冷机尾气除尘进行分析的基础上,提出了电除尘改袋式除尘的必要性,可有效控制新型干法窑烟尘和粉尘的排放浓度;针对具体案例的使用结果进行了阐述。%  The important point of environmental protection at the new dry cement kiln is that how to effectively control the concentration of dust emission under the new environmental standards in China. This paper puts forward the necessity of ESP retroft to FF technology based on the analysis on cement processing tail gas dedusting, and an introduction of the use result of specifc case concerned.

  12. Release Process on Quality Improvement in Open Source Software Project Management

    Directory of Open Access Journals (Sweden)

    S. Chandra Kumar Mangalam

    2012-01-01

    Full Text Available Problem statement: The Software Industry has changed and developed as a consequence of the impact of Open Source Software (OSS since 1990s. Over a period of time, OSS has evolved in an integrated manner and most of the participants in OSS activity are volunteers. Approach: This coordination form of development has produced a considerable quantity of software; and often, the development method has been viewed as an unorganized and unstructured method of development. Few existing researches deal with the Open Source Software phenomenon from a quality perception point of view and studies where enhancements are possible in the development process. Results: Release Process in OSS plays a key role in most of the OSS projects. As this process is related to the evolution of a quality software from the community of OSS developers, this research attempts to explore the process practices which are employed by OSS developers and examines the problems associated with the development process. The scope of the study is mainly confined to process management in OSS. “Prototype development and iterative development process” approaches were adapted as a methodology. Conclusion/Recommendations: The major finding and conclusion drawn is ‘lack of coordination among developers’ who are geographically isolated. Hence, the study suggests the need for coordination among developers to line up their development process for achieving the goal of the software release process.

  13. Effects of laser ablation on cemented tungsten carbide surface quality

    Energy Technology Data Exchange (ETDEWEB)

    Tan, J.L.; Butler, D.L.; Sim, L.M.; Jarfors, A.E.W. [Singapore Institute of Manufacturing Technology, Singapore (Singapore)

    2010-11-15

    Although laser micromachining has been touted as being the most promising way to fabricate micro tools, there has been no proper evaluation of the effects of laser ablation on bulk material properties. The current work demonstrates the effects of laser ablation on the properties of a cemented tungsten carbide surface. Of particular interest is the resultant increase in compressive residual stresses in the ablated surface. From this study it is seen that there are no adverse effects from laser ablation of cemented tungsten carbide that would preclude its use for the fabrication of micro-tools but a finishing process may not be avoidable. (orig.)

  14. Effects of laser ablation on cemented tungsten carbide surface quality

    Science.gov (United States)

    Tan, J. L.; Butler, D. L.; Sim, L. M.; Jarfors, A. E. W.

    2010-11-01

    Although laser micromachining has been touted as being the most promising way to fabricate micro tools, there has been no proper evaluation of the effects of laser ablation on bulk material properties. The current work demonstrates the effects of laser ablation on the properties of a cemented tungsten carbide surface. Of particular interest is the resultant increase in compressive residual stresses in the ablated surface. From this study it is seen that there are no adverse effects from laser ablation of cemented tungsten carbide that would preclude its use for the fabrication of micro-tools but a finishing process may not be avoidable.

  15. Statistical process monitoring based on orthogonal multi-manifold projections and a novel variable contribution analysis.

    Science.gov (United States)

    Tong, Chudong; Shi, Xuhua; Lan, Ting

    2016-11-01

    Multivariate statistical methods have been widely applied to develop data-based process monitoring models. Recently, a multi-manifold projections (MMP) algorithm was proposed for modeling and monitoring chemical industrial processes, the MMP is an effective tool for preserving the global and local geometric structure of the original data space in the reduced feature subspace, but it does not provide orthogonal basis functions for data reconstruction. Recognition of this issue, an improved version of MMP algorithm named orthogonal MMP (OMMP) is formulated. Based on the OMMP model, a further processing step and a different monitoring index are proposed to model and monitor the variation in the residual subspace. Additionally, a novel variable contribution analysis is presented for fault diagnosis by integrating the nearest in-control neighbor calculation and reconstruction-based contribution analysis. The validity and superiority of the proposed fault detection and diagnosis strategy are then validated through case studies on the Tennessee Eastman benchmark process.

  16. SCIENTIFIC AND TECHNICAL PRECONDITIONS FOR EXTRUDED LIGHTWEIGHT CEMENT SYSTEMS

    Directory of Open Access Journals (Sweden)

    Oreshkin Dmitriy Vladimirovich

    2012-10-01

    The paper also presents the results of the research of the microstructure of spilt Portland cement and hollow glass spheres, their mineral and chemical analyses, as well as the properties of masonry mortars. The paper presents a conclusion that their high process-dependent parameters and superior operating performance are attainable through the introduction of effective hollow glass spheres into masonry mortars and the application of the extrusion method. The aforementioned novelties may reduce the water consumption rate, improve the strength, freeze resistance and durability of cement mortars. The preparation of this paper involved the study of nine reference books. This paper is the first one of a series of papers covering the method of extrusion of lightweight cement mortars.

  17. Composite Control of Precalciner Exit Temperature in Cement Rotary Kiln

    Institute of Scientific and Technical Information of China (English)

    赵晨; 诸静

    2003-01-01

    A composite control strategy for the precalciner exit temperature in cement kiln is introduced based on a mathematical model. In this model, the raw meal flow, coal powder flow and wind flow are taken as three input variables, the clinker fow and exit teperature of cement kiln are output variables, and other influencing factors are considered as disturbance. A composite control system is synthesied by integrating self-learning PID, fuzzy and feedforward function into a combined controller, and the arithmetics for the self-learning PID controller, fuzzy controller and feedforward controller are elaborated respectively. The control strategy has been realized by software in real practice at cement factory. Application results show that the composite control technology is superior to the general PID control in control effect, and is suitable to the industrial process control with slow parameter variation, nonlinearity and uncertainty.

  18. Test plan for formulation and evaluation of grouted waste forms with shine process wastes

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, W. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Jerden, J. L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    The objective of this experimental project is to demonstrate that waste streams generated during the production of Mo99 by the SHINE Medical Technologies (SHINE) process can be immobilized in cement-based grouted waste forms having physical, chemical, and radiological stabilities that meet regulatory requirements for handling, storage, transport, and disposal.

  19. PERFORMANCE OF PULVERIZED SLAG-SUBSTITUTED CEMENT

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The Portland cement is equivalently substituted by slag micropowders with various specific areas. The workability,activity and acid-corrosion resistance of the slag-substituted cements are investigated,the activation of gypsum is discussed,also the porosity and pore distribution of mortars of the slag micropowders cement are determined by mercury intrusion porosimetry.

  20. 21 CFR 872.3275 - Dental cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental cement. 872.3275 Section 872.3275 Food and... DENTAL DEVICES Prosthetic Devices § 872.3275 Dental cement. (a) Zinc oxide-eugenol—(1) Identification... filling or as a base cement to affix a temporary tooth filling, to affix dental devices such as crowns...

  1. Cementation in adhesive dentistry: the weakest link

    NARCIS (Netherlands)

    Jongsma, L.A.

    2012-01-01

    Het succesvol bevestigen van tandrestauraties is een belangrijke en veeleisende procedure. Met behulp van cement wordt het restauratiemateriaal aan de tandstructuur verbonden. Op die manier worden twee hechtvlakken gecreëerd: het raakvlak tussen tand en cement, en het raakvlak tussen cement en resta

  2. The Improvement Project in Postponement of Bankruptcy Process: An Evaluation from the Business Point of View

    Directory of Open Access Journals (Sweden)

    Mahmut Ozdevecioglu

    2010-07-01

    Full Text Available It is inevitable for the capital companies and cooperatives in Turkey to go bankrupt in case the assets of the company are insufficient to meet the obligations. However, the law enacted in 2004 has enabled the bankruptcy to be postponed. The company requesting the adjournment of bankruptcy should not only fulfill the legal requirements but also present the court a convincing and serious improvement project. The main objective of this study is to discuss how to prepare such a plan from the point of view of business manager. The improvement project is a financial project based on objective and solid data which contains precautionary measures envisaged to rescue the company. In general the project should incorporate financial and administrative measures. Financial measures include direct and indirect cash inflows from sources like finding new partners, selling personal assets of existing partners and focusing on high profit margin products to ensure that the assets can cover the liabilities. The administrative measures in the field of accounting, finance and human resources contribute to the healing process indirectly. This paper explains the financial and administrative measures in detail.

  3. The process evaluation of It's Your Move!, an Australian adolescent community-based obesity prevention project

    Directory of Open Access Journals (Sweden)

    Simmons Annie M

    2010-07-01

    Full Text Available Abstract Background Evidence on interventions for preventing unhealthy weight gain in adolescents is urgently needed. The aim of this paper is to describe the process evaluation for a three-year (2005-2008 project conducted in five secondary schools in the East Geelong/Bellarine region of Victoria, Australia. The project, 'It's Your Move!' aimed to reduce unhealthy weight gain by promoting healthy eating patterns, regular physical activity, healthy body weight, and body size perception amongst youth; and improve the capacity of families, schools, and community organisations to sustain the promotion of healthy eating and physical activity in the region. Methods The project was supported by Deakin University (training and evaluation, a Reference Committee (strategic direction, budgetary approval and monitoring and a Project Management Committee (project delivery. A workshop of students, teachers and other stakeholders formulated a 10-point action plan, which was then translated into strategies and initiatives specific to each school by the School Project Officers (staff members released from teaching duties one day per week and trained Student Ambassadors. Baseline surveys informed intervention development. Process data were collected on all intervention activities and these were collated and enumerated, where possible, into a set of mutually exclusive tables to demonstrate the types of strategies and the dose, frequency and reach of intervention activities. Results The action plan included three guiding objectives, four on nutrition, two on physical activity and one on body image. The process evaluation data showed that a mix of intervention strategies were implemented, including social marketing, one-off events, lunch time and curriculum programs, improvements in infrastructure, and healthy school food policies. The majority of the interventions were implemented in schools and focused on capacity building and healthy eating strategies as

  4. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well

  5. Transient and residual stresses and displacements in self-curing bone cement - Part I: characterization of relevant volumetric behavior of bone cement.

    Science.gov (United States)

    Ahmed, A M; Pak, W; Burke, D L; Miller, J

    1982-02-01

    In this first part of a two-part report, some aspects of the volumetric behavior of bone cement during its curing process are examined as a prelude to an analysis for the transient and residual stresses and displacements in stem fixation systems. Experiments show that stress generation in the cement is associated with its temperature while curing and that during the cooling phase, the stresses are mainly due to thermal as opposed to bulk shrinkage. The appropriate coefficient of thermal expansion of bone cement has been evaluated from measurements in a simulated fixation system in conjuction with a thermoelastic analysis.

  6. 3D Simulation of micromechanical behavior of cement paste

    NARCIS (Netherlands)

    Qian, Z.; Ye, G.; Schlangen, H.E.J.G.; Van Breugel, K.

    2010-01-01

    Numerical modeling of fracture processes of brittle materials, such as cement paste, mortar, concrete and rocks, started in the late 1960s when the discrete and smeared cracking models were introduced. In the 1990s, Schlangen and van Mier proposed another numerical model to compensate the drawbacks

  7. Ensemble Eclipse: A Process for Prefab Development Environment for the Ensemble Project

    Science.gov (United States)

    Wallick, Michael N.; Mittman, David S.; Shams, Khawaja, S.; Bachmann, Andrew G.; Ludowise, Melissa

    2013-01-01

    This software simplifies the process of having to set up an Eclipse IDE programming environment for the members of the cross-NASA center project, Ensemble. It achieves this by assembling all the necessary add-ons and custom tools/preferences. This software is unique in that it allows developers in the Ensemble Project (approximately 20 to 40 at any time) across multiple NASA centers to set up a development environment almost instantly and work on Ensemble software. The software automatically has the source code repositories and other vital information and settings included. The Eclipse IDE is an open-source development framework. The NASA (Ensemble-specific) version of the software includes Ensemble-specific plug-ins as well as settings for the Ensemble project. This software saves developers the time and hassle of setting up a programming environment, making sure that everything is set up in the correct manner for Ensemble development. Existing software (i.e., standard Eclipse) requires an intensive setup process that is both time-consuming and error prone. This software is built once by a single user and tested, allowing other developers to simply download and use the software

  8. Microstructure and mechanical properties of WC-Ni-Al based cemented carbides developed for engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Edmilson O.; Santos, Julio N. [Universidade Federal de Itajuba, Minas Gerais (Brazil). Inst. de Engenharia Mecanica; Klein, Aloisio N. [Universidade Federal de Santa Catarina, Florianopolis (Brazil). Dept. de Engenharia de Materiais

    2011-11-15

    In this paper the influence of the Ni binder metal and Al as an additional alloying element on the microstructure and mechanical properties of WC-based cemented carbides processed by conventional powder metallurgy was studied. Microstructural examinations of the cemented carbides with 3 and 5 wt.% of Al in the binder metal indicated the presence of a very low and evenly distributed porosity as well as the presence of islands of metal binder in the microstructure. With the cemented carbide with 7 wt.% of Al in the metal binder, the presence of brittle needle-like regions was observed. The WC particles inside these regions were rounded and had a larger mean free path. Vickers hardness and flexural strength tests indicated that the cemented carbide WC-Ni - Al with addition of 5 wt.% of Al in the binder metal presented bulk hardness similar to the conventional WC-Co cemented carbides as well as superior flexure strength and fracture toughness. (orig.)

  9. SO2 Release as a Consequence of Alternative Fuel Combustion in Cement Rotary Kiln Inlets

    OpenAIRE

    Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter; Dam-Johansen, Kim

    2015-01-01

    The combustion of alternative fuels in direct contact with the bed material of the rotary kiln may cause local reducing conditions and, subsequently, decomposition of sulfates from cement raw materials, increasing the SO2 concentration in the gas phase. The decomposition of sulfates increases the sulfur circulation and may be problematic because high sulfur circulation can cause sticky material buildup, affecting the process operation of the cement kiln system. The SO2 release from cement raw...

  10. Technical Difficulties of Environmental Protection Acceptance for Cement Projects in Electronic Components Manufacturing Industry%电子元件行业环保验收监测技术难点研究

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    This paper discussed the technical difficulties of environmental protection for the acceptance and monitoring of e-lectronic components manufacturing industry based on the practical experience and regulatory requirements in combination with technical guidelines for environmental protection acceptance of completed construction projects and the current situation in elec-tronic components manufacturing industry .In view of the technical difficulties of the process analysis of electronic components in-dustry, the determination of pollution factors, the verification of hazardous waste, and the implementation of the inspection and acceptance standards.This works provide a reference for environmental protection in electronic components manufacturing industry construction projects for check/acceptance completed project.%根据建设项目竣工环境保护验收规范要求及当前电子元件行业的发展情况,结合工作实践,探讨新形势下电子元件行业项目竣工环境保护验收监测工作中的技术难点,针对电子元件行业工艺分析及特征污染因子的确定、危险废物核查、验收监测标准执行等技术难点提出了具体解决建议,为电子元件行业项目竣工环境保护验收监测提供参考。

  11. Final Report Collaborative Project. Improving the Representation of Coastal and Estuarine Processes in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frank [National Center for Atmospheric Research, Boulder, CO (United States); Dennis, John [National Center for Atmospheric Research, Boulder, CO (United States); MacCready, Parker [Univ. of Washington, Seattle, WA (United States); Whitney, Michael [Univ. of Connecticut

    2015-11-20

    This project aimed to improve long term global climate simulations by resolving and enhancing the representation of the processes involved in the cycling of freshwater through estuaries and coastal regions. This was a collaborative multi-institution project consisting of physical oceanographers, climate model developers, and computational scientists. It specifically targeted the DOE objectives of advancing simulation and predictive capability of climate models through improvements in resolution and physical process representation. The main computational objectives were: 1. To develop computationally efficient, but physically based, parameterizations of estuary and continental shelf mixing processes for use in an Earth System Model (CESM). 2. To develop a two-way nested regional modeling framework in order to dynamically downscale the climate response of particular coastal ocean regions and to upscale the impact of the regional coastal processes to the global climate in an Earth System Model (CESM). 3. To develop computational infrastructure to enhance the efficiency of data transfer between specific sources and destinations, i.e., a point-to-point communication capability, (used in objective 1) within POP, the ocean component of CESM.

  12. Formation, release and control of dioxins in cement kilns.

    Science.gov (United States)

    Karstensen, Kåre Helge

    2008-01-01

    Co-processing of hazardous wastes in cement kilns have for decades been thought to cause increased emissions of PCDD/PCDFs--a perception that has been evaluated in this study. Hundreds of PCDD/PCDF measurements conducted by the cement industry and others in the last few years, on emissions and solid materials, as well as recent test burns with hazardous wastes in developing countries do not support this perception. Newer data has been compared with older literature data and shows in particular that many emission factors have to be reconsidered. Early emission factors for cement kilns co-processing hazardous waste, which are still used in inventories, are shown to be too high compared with actual measurements. Less than 10 years ago it was believed that the cement industry was the main contributor of PCDD/PCDFs to air; data collected in this study indicates however that the industry contributes with less than 1% of total emissions to air. The Stockholm Convention on POPs presently ratified by 144 parties, classifies cement kilns co-processing hazardous waste as a source category having the potential for comparatively high formation and release of PCDD/PCDFs. This classification is based on early investigations from the 1980s and 1990s where kilns co-processing hazardous waste had higher emissions compared to those that did not burn hazardous waste. However, the testing of these kilns was often done under worst case scenario conditions known to favour PCDD/PCDF formation. More than 2000 PCDD/PCDF cement kiln measurements have been evaluated in this study, representing most production technologies and waste feeding scenarios. They generally indicate that most modern cement kilns co-processing waste today can meet an emission level of 0.1ngI-TEQ/m(3), when well managed and operated. In these cases, proper and responsible use of waste including organic hazardous waste to replace parts of the fossil fuel does not seem to increase formation of PCDD/PCDFs. Modern preheater

  13. Cement Pastes and Mortars Containing Nitrogen-Doped and Oxygen-Functionalized Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Mauricio Martínez-Alanis

    2016-01-01

    Full Text Available Cement pastes and mortars based on ordinary Portland cement containing nitrogen-doped multiwalled carbon nanotubes (MWCNT-Nx or oxygen-functionalized multiwalled carbon nanotubes (MWCNT-Ox are investigated. To incorporate MWCNTs into the cementitious matrix, the as-produced carpets are dispersed over periods of 1 and 2 hours in distilled water at pH levels of 1 and 7. The cement pastes are prepared by adding 0.1 wt% of MWCNTs to cement powder, followed by characterization with SEM and X-ray diffraction (XRD at an early age (first hours of hydration. The mortars are mechanically characterized during the hydration process for a period of 28 days. SEM characterization of cement pastes revealed that the carbon nanotubes are well incorporated in the cementitious matrix, with the hydrated cement grains interconnected by long carbon nanotubes. XRD characterizations demonstrated that, during the hydration of cement pastes, different peaks emerged that were associated with ettringite, hydrated calcium silicate, and calcium hydroxide, among other structures. Results of the compressive strength measurements for mortars simultaneously mixed with MWCNT-Nx and MWCNT-Ox reached an increment of approximately 30% in compressive strength. In addition, density functional theory calculations were performed in nitrogen-doped and oxygen-functionalized carbon nanotubes interacting with a cement grain.

  14. The use of RANKL-coated brushite cement to stimulate bone remodelling.

    Science.gov (United States)

    Le Nihouannen, Damien; Hacking, S Adam; Gbureck, Uwe; Komarova, Svetlana V; Barralet, Jake E

    2008-08-01

    Calcium phosphate cements were first proposed as synthetic bone substitutes over two decades ago, however, they are characterised by slow chemical or cellular resorption and a slow osteointegration. In contrast, bone autograft has been shown to stimulate osteoclastogenesis and angiogenesis resulting in active bone remodelling and rapid graft incorporation. Therefore, we aimed to develop a biomaterial able to release a key stimulator of the bone remodelling process, cytokine RANKL. Cylinders of brushite cement, hydroxyapatite cement and sodium alginate were loaded with RANKL either by incorporation into the cement or by coating the material with soluble RANKL. To test the biological activity of these formulations, we assessed their effectiveness in inducing osteoclast formation from RAW 264.7 monocytic cell line. Only brushite and hydroxyapatite cements coated with RANKL allowed for retaining sufficient biological activity to induce osteoclast formation. Most efficient was coating 40 mg cylinder of brushite cement with 800 ng RANKL. We have found that RANKL-coated brushite cement exhibits osteoclastogenic activity for at least 1 month at 37 degrees C. Thus, we developed a formulation of brushite cement with RANKL - a synthetic bone graft that is similar to autografts in its ability to actively induce osteoclastogenesis.

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

    Science.gov (United States)

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

    2015-06-01

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

  16. The biocompatibility of porous vs non-porous bone cements: a new methodological approach

    Directory of Open Access Journals (Sweden)

    C. Dall'Oca

    2014-06-01

    Full Text Available Composite cements have been shown to be biocompatible, bioactive, with good mechanical properties and capability to bind to the bone. Despite these interesting characteristic, in vivo studies on animal models are still incomplete and ultrastructural data are lacking. The acquisition of new ultrastructural data is hampered by uncertainties in the methods of preparation of histological samples due to the use of resins that melt methacrylate present in bone cement composition. A new porous acrylic cement composed of polymethylmetacrylate (PMMA and β-tricalciumphosphate (β-TCP was developed and tested on an animal model. The cement was implanted in femurs of 8 New Zealand White rabbits, which were observed for 8 weeks before their sacrifice. Histological samples were prepared with an infiltration process of LR white resin and then the specimens were studied by X-rays, histology and scanning electron microscopy (SEM. As a control, an acrylic standard cement, commonly used in clinical procedures, was chosen. Radiographic ultrastructural and histological exams have allowed finding an excellent biocompatibility of the new porous cement. The high degree of osteointegration was demonstrated by growth of neo-created bone tissue inside the cement sample. Local or systemic toxicity signs were not detected. The present work shows that the proposed procedure for the evaluation of biocompatibility, based on the use of LR white resin allows to make a thorough and objective assessment of the biocompatibility of porous and non-porous bone cements.

  17. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust.

    Science.gov (United States)

    Moon, Deok Hyun; Grubb, Dennis G; Reilly, Trevor L

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO(3).H(2)O) and selenate substituted ettringite (Ca(6)Al(2)(SeO(4))(3)(OH)(12).26H(2)O), respectively.

  18. Evaluation of helium impurity impacts on Spent Nuclear Fuel project processes (OCRWM)

    Energy Technology Data Exchange (ETDEWEB)

    SHERRELL, D.L.

    1999-09-21

    This document identifies the types and quantities of impurities that may be present within helium that is introduced into multi-canister overpacks (MCO)s by various SNF Project facilities, including, but not limited to the Cold Vacuum Drying (CVD) Facility (CVDF). It then evaluates possible impacts of worst case impurity inventories on MCO drying, transportation, and storage processes. Based on the evaluation results, this document: (1) concludes that the SNF Project helium procurement specification can be a factor-of-ten less restrictive than a typical vendor's standard offering (99.96% pure versus the vendor's 99.997% pure standard offering); (2) concludes that the CVDF's current 99.5% purity requirement is adequate to control the quality of the helium that is delivered to the MCO by the plant's helium distribution system; and (3) recommends specific impurity limits for both of the above cases.

  19. Watching Cement Dry

    Institute of Scientific and Technical Information of China (English)

    Stephen Green

    2010-01-01

    @@ Today, we look at what is happening in China's investment sector. We make a number of observations: A large number of new projects continue to start under local government sponsorship, meaning that real investment activity will continue to be strong in 2010. We have not yet seen the peak in demand for construction-related commodities (or labour) generated by China's stimulus package.

  20. Substitution of the clayey mineral component by lignite fly ash in portland cement clinker synthesis

    Directory of Open Access Journals (Sweden)

    Jovanović Nataša

    2006-01-01

    Full Text Available Fly ash from four power plants in Serbia (PP "Morava" - Svilajnac, PP "Kolubara" - Veliki Grijani, PP "Kostolac" - units B1 and B2 - Kostolac and PP "Nikola Tesla" - units A and B - Obrenovac was utilized as the starting raw component for Portland cement clinker synthesis. Limestone and quartz sand from the "Holcim - Serbia, a.d." cement factory were the other two starting raw components. Based on the chemical composition of the raw components and from the projected cement moduli, the amounts of raw components in the raw mixtures were calculated. Six different raw mixtures were prepared - each one consisted of limestone, sand and different fly ash. A raw mixture from the industrial production of the "Holcim - Serbia, a.d." cement factory was used as the reference material. The prepared raw mixtures were sintered in a laboratory furnace at 1400°C. The chemical and mineralogical compositions of the synthesized clinkers were determined. The characteristics of clinkers, based on fly ash, were compared to the characteristics of the industrial Portland cement clinker from the "Holcim - Serbia, a.d." cement factory. The results of the investigation showed that fly ash from power plants in Serbia can be suitable for Portland cement clinker synthesis.

  1. Commercial Light Water Reactor -Tritium Extraction Facility Process Waste Assessment (Project S-6091)

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, R.H.; Delley, A.O.; Alexander, G.J.; Clark, E.A.; Holder, J.S.; Lutz, R.N.; Malstrom, R.A.; Nobles, B.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Carson, S.D. [Sandia National Laboratories, New Mexico, NM (United States); Peterson, P.K. [Sandia National Laboratories, New Mexico, NM (United States)

    1997-11-30

    The Savannah River Site (SRS) has been tasked by the Department of Energy (DOE) to design and construct a Tritium Extraction Facility (TEF) to process irradiated tritium producing burnable absorber rods (TPBARs) from a Commercial Light Water Reactor (CLWR). The plan is for the CLWR-TEF to provide tritium to the SRS Replacement Tritium Facility (RTF) in Building 233-H in support of DOE requirements. The CLWR-TEF is being designed to provide 3 kg of new tritium per year, from TPBARS and other sources of tritium (Ref. 1-4).The CLWR TPBAR concept is being developed by Pacific Northwest National Laboratory (PNNL). The TPBAR assemblies will be irradiated in a Commercial Utility light water nuclear reactor and transported to the SRS for tritium extraction and processing at the CLWR-TEF. A Conceptual Design Report for the CLWR-TEF Project was issued in July 1997 (Ref. 4).The scope of this Process Waste Assessment (PWA) will be limited to CLWR-TEF processing of CLWR irradiated TPBARs. Although the CLWR- TEF will also be designed to extract APT tritium-containing materials, they will be excluded at this time to facilitate timely development of this PWA. As with any process, CLWR-TEF waste stream characteristics will depend on process feedstock and contaminant sources. If irradiated APT tritium-containing materials are to be processed in the CLWR-TEF, this PWA should be revised to reflect the introduction of this contaminant source term.

  2. New process modeling [sic], design, and control strategies for energy efficiency, high product quality, and improved productivity in the process industries. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Ray, W. Harmon

    2002-06-05

    This project was concerned with the development of process design and control strategies for improving energy efficiency, product quality, and productivity in the process industries. In particular, (i) the resilient design and control of chemical reactors, and (ii) the operation of complex processing systems, was investigated. Specific topics studied included new process modeling procedures, nonlinear controller designs, and control strategies for multiunit integrated processes. Both fundamental and immediately applicable results were obtained. The new design and operation results from this project were incorporated into computer-aided design software and disseminated to industry. The principles and design procedures have found their way into industrial practice.

  3. Improving science literacy: The knowledge-transforming process within an on-line professional development project

    Science.gov (United States)

    Sherwood, Susan A.

    2008-10-01

    This study examined connections between science literacy and writing. Science e-mails were written as content-oriented professional development materials for K-8 teachers. E-mail drafts underwent multiple revisions. The study data included drafts, final e-mails, and feedback from the supervising scientist and the e-mails' teacher audience. The analyses, informed by Bereiter & Scardamalia's knowledge-transforming process (1987), Schindler's audience theories (2001), and Johnson and Aragon's on-line instruction framework (2003), sought connections among three components: the writer's struggle between content and discourse, audience, and format. The e-mail drafts indicated a large percentage of text changes involving two or more of the components, primarily concerning discourse. Redundancies surfaced among the components, indicating Bereiter and Scardamalia's knowledge-transforming process sufficiently explained the e-mail project; additional format and audience models were unnecessary. Recommendations for extending the knowledge-transforming process specifically for science are included.

  4. Energy recovery from wastes : experience with solid alternative fuels combustion in a precalciner cement kiln

    OpenAIRE

    Tokheim, Lars-André; Gautestad, Tor; Axelsen, Ernst Petter; Bjerketvedt, Dag

    2001-01-01

    Today virtually all cement clinker burning processes take place in rotary kilns. A mixture of calcareous and argilaceous materials is heated to a temperature of about 1450 °C. In this process decarbonation followed by partial fusion occurs, and nodules of so-called clinker are formed. The cooled clinker is mixed with a few percent of gypsum, and ground into a fine meal – cement. The most modern cement kilns are equipped with a precalciner, in which most of the calcium carbonate...

  5. Microwave assisted preparation of magnesium phosphate cement (MPC) for orthopedic applications: A novel solution to the exothermicity problem

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Huan, E-mail: Huan.Zhou@rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH 43606 (United States); Agarwal, Anand K.; Goel, Vijay K. [Department of Bioengineering, The University of Toledo, Toledo, OH 43606 (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH 43606 (United States); Division of Dentistry, The University of Toledo, Toledo, OH 43606 (United States)

    2013-10-15

    There are two interesting features of this paper. First, we report herein a novel microwave assisted technique to prepare phosphate based orthopedic cements, which do not generate any exothermicity during setting. The exothermic reactions during the setting of phosphate cements can cause tissue damage during the administration of injectable compositions and hence a solution to the problem is sought via microwave processing. This solution through microwave exposure is based on a phenomenon that microwave irradiation can remove all water molecules from the alkaline earth phosphate cement paste to temporarily stop the setting reaction while preserving the active precursor phase in the formulation. The setting reaction can be initiated a second time by adding aqueous medium, but without any exothermicity. Second, a special emphasis is placed on using this technique to synthesize magnesium phosphate cements for orthopedic applications with their enhanced mechanical properties and possible uses as drug and protein delivery vehicles. The as-synthesized cements were evaluated for the occurrences of exothermic reactions, setting times, presence of Mg-phosphate phases, compressive strength levels, microstructural features before and after soaking in (simulated body fluid) SBF, and in vitro cytocompatibility responses. The major results show that exposure to microwaves solves the exothermicity problem, while simultaneously improving the mechanical performance of hardened cements and reducing the setting times. As expected, the cements are also found to be cytocompatible. Finally, it is observed that this process can be applied to calcium phosphate cements system (CPCs) as well. Based on the results, this microwave exposure provides a novel technique for the processing of injectable phosphate bone cement compositions. - Highlights: • A microwave assisted system for bone cement manufacturing • A solution to exothermicity problem of acid–base reaction based bone cement

  6. ACSEPT a European project for a new step in the future demonstration of advanced fuel processing

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, S.; Hill, C. [CEA, DRCP - Bat 181, CEA Marcoule, BP17171, 30207 Bagnols/Ceze (France); Caravaca, C.; Espartero, A. [CIEMAT, Avda. Complutense, 22 - 28040 Madrid (Spain); Rhodes, C.; Taylor, R.; Harrison, M. [National Nuclear Laboratory, Sellafield, Seascale, Cumbria, CA20 1PG (United Kingdom); EKBERG, C. [Chalmers tekniska hoegskola, Institutionen foer kemi- och bioteknik, Aemnesomraadets namn, 412 96 Goeteborg (Sweden); GEIST, A. [Forschungszentrum Karlsruhe, Institut fuer Nukleare Entsorgungstechnik, P.O.B. 3640, D-76021 Karlsruhe (Germany); Modolo, G. [Forschungszentrum Juelich - FZJ, D-52425 Juelich (Germany); Cassayre, L. [CNRS, Laboratoire de Genie Chimique, Toulouse (France); Malmbeck, R. [JRC-ITU, Karlsruhe (Germany); De Angelis, G. [ENEA, Casaccia, Rome (Italy); Bouvet, S. [Rio Tinto Alcan, Centre de Recherche de Voreppe, Voreppe (France); Klaassen, F. [NRG, PO Box 25, NL-1755 ZG Petten (Netherlands)

    2010-07-01

    For more than fifteen years, a European scientific community has joined its effort to develop and optimise processes for the partitioning of actinides from fission products. In an international context of 'nuclear renaissance', the upcoming of a new generation of nuclear reactor (Gen IV) will require the development of associated advanced closed fuel cycles which answer the needs of a sustainable nuclear energy: the minimization of the production of long lived radioactive waste but also the optimization of the use of natural resources with an increased resistance to proliferation. Actually, Partitioning and Transmutation (P and T), associated to a multi-recycling of all transuranics (TRUs), should play a key role in the development of this sustainable nuclear energy. By joining together 34 Partners coming from European universities, nuclear research bodies and major industrial players in a multidisciplinary consortium, the FP7 EURATOM-Fission Collaborative Project ACSEPT (Actinide recycling by Separation and Transmutation), started in 2008 for four year duration, provides the sound basis and fundamental improvements for future demonstrations of fuel treatment in strong connection with fuel fabrication techniques. Consistently with potentially viable recycling strategies, ACSEPT therefore provides a structured R and D framework to develop chemical separation processes compatible with fuel fabrication techniques, with a view to their future demonstration at the pilot level. ACSEPT is organized into three technical domains: (i) Considering technically mature aqueous separation processes, ACSEPT works to optimize and select the most promising ones dedicated either to actinide partitioning or to group actinide separation. (ii) Concerning high temperature pyrochemical separation processes, ACSEPT focuses on the enhancement of the two reference cores of process selected within previous projects. R and D efforts are now devoted to key scientific and technical

  7. Development of a set of process and structure indicators for palliative care: the Europall project

    Directory of Open Access Journals (Sweden)

    Woitha Kathrin

    2012-11-01

    Full Text Available Abstract Background By measuring the quality of the organisation of palliative care with process and structure quality indicators (QIs, patients, caregivers and policy makers are able to monitor to what extent recommendations are met, like those of the council of the WHO on palliative care and guidelines. This will support the implementation of public programmes, and will enable comparisons between organisations or countries. Methods As no European set of indicators for the organisation of palliative care existed, such a set of QIs was developed. An update of a previous systematic review was made and extended with more databases and grey literature. In two project meetings with practitioners and experts in palliative care the development process of a QI set was finalised and the QIs were categorized in a framework, covering the recommendations of the Council of Europe. Results The searches resulted in 151 structure and process indicators, which were discussed in steering group meetings. Of those QIs, 110 were eligible for the final framework. Conclusions We developed the first set of QIs for the organisation of palliative care. This article is the first step in a multi step project to identify, validate and pilot QIs.

  8. Nonoptimal component placement, but short processing paths, due to long-distance projections in neural systems.

    Directory of Open Access Journals (Sweden)

    Marcus Kaiser

    2006-07-01

    Full Text Available It has been suggested that neural systems across several scales of organization show optimal component placement, in which any spatial rearrangement of the components would lead to an increase of total wiring. Using extensive connectivity datasets for diverse neural networks combined with spatial coordinates for network nodes, we applied an optimization algorithm to the network layouts, in order to search for wire-saving component rearrangements. We found that optimized component rearrangements could substantially reduce total wiring length in all tested neural networks. Specifically, total wiring among 95 primate (Macaque cortical areas could be decreased by 32%, and wiring of neuronal networks in the nematode Caenorhabditis elegans could be reduced by 48% on the global level, and by 49% for neurons within frontal ganglia. Wiring length reductions were possible due to the existence of long-distance projections in neural networks. We explored the role of these projections by comparing the original networks with minimally rewired networks of the same size, which possessed only the shortest possible connections. In the minimally rewired networks, the number of processing steps along the shortest paths between components was significantly increased compared to the original networks. Additional benchmark comparisons also indicated that neural networks are more similar to network layouts that minimize the length of processing paths, rather than wiring length. These findings suggest that neural systems are not exclusively optimized for minimal global wiring, but for a variety of factors including the minimization of processing steps.

  9. Transient and residual stresses and displacements in self-curing bone cement - Part II: thermoelastic analysis of the stem fixation system.

    Science.gov (United States)

    Ahmed, A M; Nair, R; Burke, D L; Miller, J

    1982-02-01

    In this second part of a two-part report, an idealized model of the stem fixation system is analyzed to determine the adverse effects of the thermal stresses and displacements of bone cement during its curing process. The Shaffer-Levitsky stress-rate strain-rate law for chemically hardening material has been used. The results show that if the cement is surrounded by cancellous bone, as opposed to cortical bone, then transient tensile circumferential stresses in the cement and similar radial stresses at the stem/cement interface are generated. The former may cause flaws and voids within the still cement, while the latter may cause gaps at the interface.

  10. Software tools of the Computis European project to process mass spectrometry images.

    Science.gov (United States)

    Robbe, Marie-France; Both, Jean-Pierre; Prideaux, Brendan; Klinkert, Ivo; Picaud, Vincent; Schramm, Thorsten; Hester, Atfons; Guevara, Victor; Stoeckli, Markus; Roempp, Andreas; Heeren, Ron M A; Spengler, Bernhard; Gala, Olivier; Haan, Serge

    2014-01-01

    Among the needs usually expressed by teams using mass spectrometry imaging, one that often arises is that for user-friendly software able to manage huge data volumes quickly and to provide efficient assistance for the interpretation of data. To answer this need, the Computis European project developed several complementary software tools to process mass spectrometry imaging data. Data Cube Explorer provides a simple spatial and spectral exploration for matrix-assisted laser desorption/ionisation-time of flight (MALDI-ToF) and time of flight-secondary-ion mass spectrometry (ToF-SIMS) data. SpectViewer offers visualisation functions, assistance to the interpretation of data, classification functionalities, peak list extraction to interrogate biological database and image overlay, and it can process data issued from MALDI-ToF, ToF-SIMS and desorption electrospray ionisation (DESI) equipment. EasyReg2D is able to register two images, in American Standard Code for Information Interchange (ASCII) format, issued from different technologies. The collaboration between the teams was hampered by the multiplicity of equipment and data formats, so the project also developed a common data format (imzML) to facilitate the exchange of experimental data and their interpretation by the different software tools. The BioMap platform for visualisation and exploration of MALDI-ToF and DESI images was adapted to parse imzML files, enabling its access to all project partners and, more globally, to a larger community of users. Considering the huge advantages brought by the imzML standard format, a specific editor (vBrowser) for imzML files and converters from proprietary formats to imzML were developed to enable the use of the imzML format by a broad scientific community. This initiative paves the way toward the development of a large panel of software tools able to process mass spectrometry imaging datasets in the future.

  11. Experimental Evaluation of Cement Replacement Fillers on the Performance of Slurry Seal

    Science.gov (United States)

    Fakhri, Mansour; Alrezaei, Hossein Ali; Naji Almasi, Soroush

    2016-10-01

    Reducing the level of roads service is a process that starts from the first day of the operation of road and the slope of deterioration curve of road sustainability becomes faster with the passage of time. After building the road, adopting an economic approach in order to maintain the road is very important. Slurry seal as one type of protective asphalts that works by sealing inactive cracks of the road and increasing skid resistance is the most effective types of restoration with environmentally friendly behaviour. Fillers are responsible for adjusting set time in slurry seal. Cement is the most common filler used in slurry seal. Cements having suitable properties as a filler, has a very energy demanding manufacturing process and a notable amount of energy is used for manufacturing cement in the country annually. On the other hand, manufacturing process and application of cement have increased levels of pollutant gases, followed by significant environmental pollution. So in this study other options as a filler such as hydrated lime, stone powder and the slag from iron melting furnace were compared with two common types of cement (Portland and type-v cement) in the mixtures of slurry seal by wet abrasion and cohesion tests. Results indicated that, in both tests, lime and slag fillers had behaviours close to the cement filler.

  12. Research Project Entitled "The Dynamics and Physical Processes in The Weather and Climate System" --Part Ⅰ: A Brief Introduction

    Institute of Scientific and Technical Information of China (English)

    罗云峰; 郑文静; 周小刚

    2004-01-01

    In the beginning of the 21st century, the Tenth Five-Year Priority Research Projects of the Earth Sciences of the National Natural Science Foundation of China (NSFC) were initiated. After nearly a two-year long process to prepare, the first version of six Priority Research Projects of Earth Sciences was published in October 2001 by NSFC, viz., Local Response to Global Changes, Life Process and Environment,Dynamics and Physical Processes in the Weather and Climate System, Continental Dynamics, Regional Sustainable Development, Solar-Terrestrial Environment and Space Weather. The process involved more than 200 renowned Chinese scientists and many departments and agencies in China. The six Priority Research Projects guide the research effort of the earth sciences for the NSFC from year 2001 to 2005.This paper provides a brief introduction to the Third Priority Research Project of the Department of Earth Sciences of NSFC-Dynamics and Physical Processes in the Weather and Climate System (DPWOS).

  13. Implementation of visitor pattern in processing a syntax tree in Qlab project

    Directory of Open Access Journals (Sweden)

    Đenić Aleksandar

    2012-01-01

    Full Text Available Qlab is an open-source project that supports various mathematical calculations, specialized for academic use. It has been developed at the Faculty of Mathematics, University of Belgrade, and is supported by Microsoft Serbia. In this paper we present some of Qlab’s successfully implemented core solutions. More precisely, in our approach we use a specialized Visitor pattern to optimize the management of syntax tree commands that our parser sends to our engine. This allows the processing of a larger scale of tree implementation using the Visitor interface.

  14. Expected Limits on R-symmetric $\\mu \\to e $ Processes at Project X

    CERN Document Server

    Fok, Ricky

    2012-01-01

    We investigate $\\mu \\to e$ processes in the Minimal R-symmetric Standrad Model (MRSSM) with the expected limits from Project X. It is found that $\\mu \\to e$ conversion provides the tightest bound on the $\\mu \\to e$ mixing parameters at the order of $\\lesssim O(10^{-3})$. Whereas $\\mu \\to eee$ only slightly improves the bound in the region where incoherence among different contributions to $\\mu \\to e$ is significant. No improvements on the bounds are obtained from $\\mu \\to e \\gamma$.

  15. Searching for the Unknowable: A Process of Detection — Abductive Research Generated by Projective Techniques

    Directory of Open Access Journals (Sweden)

    Miri Levin-Rozalis

    2004-06-01

    Full Text Available This article looks at the process of doing research ‘from scratch.’ The author began a project investigating children of Ethiopian origin living in Israel to see how ones who attended a kindergartern program years earlier differed from those who had not attended. However, the problem from the outset was that there may not be a difference to find. In this article, the author compares inductive, deductive, and abductive reasoning, and argues that abductive reasoning is the proper technique when nothing is known about the research at the outset.

  16. How different is mining from mineral processing? A general equilibrium analysis of new resources projects in Western Australia

    OpenAIRE

    Qiang, Ye

    1999-01-01

    Western Australia has experienced an investment surge in the minerals sector of the economy in recent years. Unlike previous surges, this one involves a large proportion of mineral‐processing projects. In this study, the differential effects on the WA economy of 25 mining and 10 mineral‐processing projects are analysed using an economy‐wide model of WA. The results indicate that: (i) both the mining and mineral‐processing projects will have substantial flow‐on benefits to the WA economy as a ...

  17. Some durability aspects of hybrid alkaline cements

    Directory of Open Access Journals (Sweden)

    Donatello S.

    2014-04-01

    Full Text Available Blended cements that contain a high content of fly ash and a low content of Portland cement typically suffer from low early strength development and long setting times. Recently, one method of overcoming these problems has been to use an alkali activator to enhance the reactivity of fly ash particles at early ages. Such cements can be grouped under the generic term “hybrid alkaline cements”, where both cement clinker and fly ash, encouraged by the presence of alkalis, are expected to contribute to cementitious gel formation. The work presented here examines some of the durability aspects of high fly ash content hybrid alkaline cement. Specifically, the aspects investigated were: exposure at high temperatures (up to 1000°C, resistance to immersion in aggressive solutions and susceptibility to the alkali aggregate reaction. All tests were repeated with a commercially available sulfate resistant Portland cement for comparison. When exposed to high temperatures, the hybrid alkaline cement showed strikingly different behaviour compared to the control Portland cement, showing fewer micro-cracks and maintaining residual compressive strengths at least equal to original strengths. Beyond 700°C, the hybrid alkaline cement began to sinter, which resulted in shrinkage of around 5% and a 100% increase in residual compressive strengths. No such sintering event was noted in the control Portland cement, which showed a drastic loss in residual compressive strengths upon heating. In immersion tests, the hybrid alkaline cement possessed excellent resistance to sulfate and seawater attack, similar to the control sulfate resistant cement. Both cements were however severely degraded by immersion in 0.1M HCl for 90 days. Both binders complied with the accelerated alkali-aggregate test but when this test was extended, the hybrid alkaline binder showed much greater dimensional stability. Possible reasons for the differences in durability behaviour in both cements

  18. Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume V: Process development

    OpenAIRE

    Gallagher, B.; P. Alexander; D.Burger

    1986-01-01

    The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. The goal of the Process Development Area, as part of the FSA Project, was to develop ...

  19. Endoscopic fringe projection for in-situ inspection of a sheet-bulk metal forming process

    Science.gov (United States)

    Matthias, Steffen; Kästner, Markus; Reithmeier, Eduard

    2015-05-01

    Sheet-bulk metal forming is a new production process capable of performing deep-drawing and massive forming steps in a single operation. However, due to the high forming forces of the forming process, continuous process control is required in order to detect wear on the forming tool before production quality is impacted. To be able to measure the geometry of the forming tool in the limited space of forming presses, a new inspection system is being developed within the SFB/TR 73 collaborative research center. In addition to the limited space, the process restricts the amount of time available for inspection. Existing areal optical measurement systems suffer from shadowing when measuring the tool's inner elements, as they cannot be placed in the limited space next to the tool, while tactile measurement systems cannot meet the time restrictions for measuring the areal geometries. The new inspection system uses the fringe projection optical measurement principle to capture areal geometry data from relevant parts of the forming tool in short time. Highresolution image fibers are used to connect the system's compact sensor head to a base unit containing both camera and projector of the fringe projection system, which can be positioned outside of the moving parts of the press. To enable short measurement times, a high intensity laser source is used in the projector in combination with a digital micro-mirror device. Gradient index lenses are featured in the sensor head to allow for a very compact design that can be used in the narrow space above the forming tool inside the press. The sensor head is attached to an extended arm, which also guides the image fibers to the base unit. A rotation stage offers the possibility to capture measurements of different functional elements on the circular forming tool by changing the orientation of the sensor head next to the forming tool. During operation of the press, the arm can be travelled out of the moving parts of the forming press

  20. Evaluation of shredder residue as cement manufacturing feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Boughton, Bob [California Environmental Protection Agency, Department of Toxic Substances Control, Office of Pollution Prevention and Technology Development, 1001 I Street, P.O. Box 806, Sacramento, CA 95812 (United States)

    2007-09-15

    Metal recycling from automobiles, appliances and scrap steel occurs at over 200 dedicated metal shredding operations in the US. Shredder residue (SR) consists of glass, rubber, plastics, fibers, dirt, and fines that remain after ferrous and non-ferrous metals have been removed. Over 3 million tonnes of SR generated in the US each year are landfilled. The results of a previous end-of-life impact assessment showed that use of SR as a fuel supplement for cement manufacturing was environmentally beneficial to the current practice of landfilling and appears better in comparison to the other management methods studied. However, because many reuse and recycling options may not be cost effective, there is a need for further study. Simplistic methods to separate SR into energy and mineral rich streams may facilitate the use of a sizable fraction of SR. Due to the large scale of the cement industry in the US, a significant amount of SR is recoverable. The goal of this study was to identify the feedstock quality parameters needed to satisfy kiln operators and then to assess the mechanical means necessary to process SR into material acceptable as coal and mineral substitutes. Field tests were conducted to separate and beneficiate the coarse SR waste stream. Density separation techniques commonly used by shredders in the past were tested to separate rubber and plastics from non-combustibles and contaminants (e.g., PVC and copper wire). A fraction constituting about 30 wt% of the total SR had fuel characteristics mirroring those of coal. However, remaining levels of potentially problematic constituents (e.g., total chlorine and heavy metals) may limit use to a low relative addition rate at some kilns. An economic review of a full-scale separation system showed that processing SR appears to be economically marginal considering avoided landfilling costs alone. However, significant economic benefits would result from additional non-ferrous metals recovery (namely copper). The